US4382745A — Method of controlling wicket gates of a pump-turb…

Claim 1

Independent Claim 141 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value out of said S-section to a negative value.

Claim 2

Dependent Claim 141 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value out of said S-section to a negative value.

Claim 3

Dependent Claim 141 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being or the type having in the turbine operation area S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value out of said S-section to a negative value.

Claim 4

Dependent Claim 141 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being or the type having in the turbine operation area S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value out of said S-section to a negative value.

Claim 5

Dependent Claim 117 words

In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area S-section where discharge per unit head (Q1) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected on the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.

Claim 6

Dependent Claim 117 words

In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area S-section where discharge per unit head (Q1) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected on the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.

Claim 7

Independent Claim 120 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having a S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: upon removal of load from the pump-turbine, reducing Q 1 and approaching the S-section; thereafter opening the wicket gates within the S-section; and thereafter closing the wicket gates.

Claim 8

Independent Claim 120 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having a S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: upon removal of load from the pump-turbine, reducing Q 1 and approaching the S-section; thereafter opening the wicket gates within the S-section; and thereafter closing the wicket gates.

Claim 9

Dependent Claim 41 words

The method of claim 4, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said step of opening when Q 1 is decreasing.

Claim 10

Dependent Claim 45 words

The method of claim 5, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 11

Dependent Claim 45 words

The method of claim 4, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 12

Dependent Claim 45 words

The method of claim 7, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 13

Dependent Claim 45 words

The method of claim 4, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 14

Dependent Claim 47 words

The method of claim 4, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.

Claim 15

Dependent Claim 55 words

A method according to claim 4, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 16

Dependent Claim 38 words

A method according to claim 4, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said step of opening when dT/dt<0 and dN/dt<0.

Claim 17

Dependent Claim 43 words

The method of claim 4, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 18

Dependent Claim 53 words

The method of claim 4, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.

Claim 19

Dependent Claim 54 words

The method of claim 14, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 20

Dependent Claim 19 words

The method of claim 4, including discontinuing said opening of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 21

Dependent Claim 41 words

The method of claim 16, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said step of opening when Q 1 is decreasing.

Claim 22

Dependent Claim 15 words

The method of claim 4, wherein said step of reducing partially closes the wicket gates.

Claim 23

Dependent Claim 41 words

The method of claim 18, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said step of opening when Q 1 is decreasing.

Claim 24

Dependent Claim 45 words

The method of claim 19, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 25

Dependent Claim 45 words

The method of claim 18, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 26

Dependent Claim 45 words

The method of claim 21, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 27

Dependent Claim 45 words

The method of claim 18, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 28

Dependent Claim 47 words

The method of claim 18, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.

Claim 29

Dependent Claim 54 words

The method of claim 18, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 30

Dependent Claim 37 words

The method of claim 18, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said step of opening when dT/dt<0 and dN/dt<0.

Claim 31

Dependent Claim 43 words

The method of claim 18, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 32

Dependent Claim 54 words

The method of claim 18, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.

Claim 33

Dependent Claim 54 words

The method of claim 28, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 34

Dependent Claim 17 words

The method of claim 18, discontinuing opening of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 35

Dependent Claim 41 words

The method of claim 30, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said step of opening when Q 1 is decreasing.

Claim 36

Dependent Claim 47 words

The method of claim 21, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.

Claim 37

Dependent Claim 54 words

The method of claim 32, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 38

Dependent Claim 43 words

The method of claim 32, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 39

Dependent Claim 19 words

The method of claim 32, including discontinuing said opening of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 40

Dependent Claim 26 words

The method of claim 18, wherein said step of closing closes the wicket gates at a rate at least as great as said step of reducing.

Claim 41

Dependent Claim 41 words

The method of claim 36, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said step of opening when Q 1 is decreasing.

Claim 42

Dependent Claim 45 words

The method of claim 37, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 43

Dependent Claim 45 words

The method of claim 36, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 44

Dependent Claim 45 words

The method of claim 39, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 45

Dependent Claim 45 words

The method of claim 36, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 46

Dependent Claim 47 words

The method of claim 36, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.

Claim 47

Dependent Claim 54 words

The method of claim 36, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 48

Dependent Claim 37 words

The method of claim 36, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said step of opening when dT/dt<0 and dN/dt<0.

Claim 49

Dependent Claim 43 words

The method of claim 36, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 50

Dependent Claim 54 words

The method of claim 36, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.

Claim 51

Dependent Claim 54 words

The method of claim 46, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 52

Independent Claim 199 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having an S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: detecting the removal of load from the turbine and in response to detecting the load removal, closing the wicket gates upon removal of load from the pump-turbine to reduce Q 1 and approach the S-section without completely closing the wicket gates; thereafter detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and discontinuing said step of closing when Q 1 is decreasing; and thereafter detecting when the discharge per unit head Q 1 is increasing within the S-section and closing the wicket gates in the S-section when the discharge per unit head Q 1 is increasing.

Claim 53

Independent Claim 199 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having an S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: detecting the removal of load from the turbine and in response to detecting the load removal, closing the wicket gates upon removal of load from the pump-turbine to reduce Q 1 and approach the S-section without completely closing the wicket gates; thereafter detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and discontinuing said step of closing when Q 1 is decreasing; and thereafter detecting when the discharge per unit head Q 1 is increasing within the S-section and closing the wicket gates in the S-section when the discharge per unit head Q 1 is increasing.

Claim 54

Dependent Claim 43 words

The method of claim 48, wherein the turbine speed and the lapsed time is detected, and said step of discontinuing is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0.

Claim 55

Dependent Claim 28 words

The method of claim 48, wherein both said steps of discontinuing and last mentioned closing are conducted when the turbine is operating below its no load discharge line.

Claim 56

Dependent Claim 56 words

The method of claim 48, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said last mentioned closing step when dP/dt<0, and dN/dt<0, wherein t is time.

Claim 57

Dependent Claim 37 words

The method of claim 48, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said step of discontinuing when dT/dt<0 and dN/dt<0.

Claim 58

Dependent Claim 43 words

The method of claim 48, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 59

Independent Claim 194 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closeable and openable to control the flow of fluid through the turbine impeller under the control of a regular controller, such as a speed governor, and having an S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: upon removal of load from the pump-turbine, reducing Q 1 and approaching the S-section with the wicket gates being closed under control from the regular controller; thereafter putting the wicket gates under an overriding control within the S-section which allows only closing speed substantially stopping and very slow closing or opening signals from said regular controller and, for any faster closing signals from said regular controller outside said closing speed range, gives an overriding signal for substantially holding at the current wicket gate position; and thereafter closing the wicket gates.

Claim 60

Independent Claim 194 words

A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closeable and openable to control the flow of fluid through the turbine impeller under the control of a regular controller, such as a speed governor, and having an S-section of its performance as a turbine defined by ∂Q 1 /∂N 1 >0, wherein Q 1 is the discharge fluid through the impeller per unit head and N 1 is the impeller speed per unit head, comprising the steps of: upon removal of load from the pump-turbine, reducing Q 1 and approaching the S-section with the wicket gates being closed under control from the regular controller; thereafter putting the wicket gates under an overriding control within the S-section which allows only closing speed substantially stopping and very slow closing or opening signals from said regular controller and, for any faster closing signals from said regular controller outside said closing speed range, gives an overriding signal for substantially holding at the current wicket gate position; and thereafter closing the wicket gates.

Claim 61

Dependent Claim 40 words

The method of claim 54, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said overriding control when Q 1 is decreasing.

Claim 62

Dependent Claim 45 words

The method of claim 55, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 63

Dependent Claim 44 words

The method of claim 54, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 64

Dependent Claim 45 words

The method of claim 57, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 65

Dependent Claim 45 words

The method of claim 54, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 66

Dependent Claim 46 words

The method of claim 54, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.

Claim 67

Dependent Claim 55 words

A method according to claim 54, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 68

Dependent Claim 37 words

A method according to claim 54, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said overriding control when dT/dt<0 and dN/dt<0.

Claim 69

Dependent Claim 43 words

The method of claim 54, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 70

Dependent Claim 54 words

The method of claim 54, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.

Claim 71

Dependent Claim 54 words

The method of claim 64, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 72

Dependent Claim 20 words

The method of claim 54, including discontinuing said overriding control of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 73

Dependent Claim 40 words

The method of claim 66, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said overriding control when Q 1 is decreasing.

Claim 74

Dependent Claim 15 words

The method of claim 54, wherein said step of reducing partially closes the wicket gates.

Claim 75

Dependent Claim 40 words

The method of claim 68, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said overriding control when Q 1 is decreasing.

Claim 76

Dependent Claim 45 words

The method of claim 69, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 77

Dependent Claim 44 words

The method of claim 68, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 78

Dependent Claim 45 words

The method of claim 71, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 79

Dependent Claim 45 words

The method of claim 68, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 80

Dependent Claim 46 words

The method of claim 68, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.

Claim 81

Dependent Claim 54 words

The method of claim 68, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0 wherein t is time.

Claim 82

Dependent Claim 36 words

The method of claim 68, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said overriding control when dT/dt<0 and dN/dt<0.

Claim 83

Dependent Claim 43 words

The method of claim 68, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 84

Dependent Claim 54 words

The method of claim 68, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.

Claim 85

Dependent Claim 54 words

The method of claim 78, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 86

Dependent Claim 19 words

The method of claim 68, discontinuing said overriding control of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 87

Dependent Claim 40 words

The method of claim 80, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said overriding control when Q 1 is decreasing.

Claim 88

Dependent Claim 46 words

The method of claim 71, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.

Claim 89

Dependent Claim 54 words

The method of claim 82, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 90

Dependent Claim 43 words

The method of claim 82, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio dQ 1 /dN 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 91

Dependent Claim 20 words

The method of claim 82, including discontinuing said overriding control of the wicket gates when ∂Q 1 /∂N 1 <0.

Claim 92

Dependent Claim 26 words

The method of claim 68, wherein said step of closing closes the wicket gates at a rate at least as great as said step of reducing.

Claim 93

Dependent Claim 40 words

The method of claim 86, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q 1 is decreasing and conducting said overriding control when Q 1 is decreasing.

Claim 94

Dependent Claim 45 words

The method of claim 87, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 95

Dependent Claim 44 words

The method of claim 86, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d 2 N/dt 2 <0, wherein t is time.

Claim 96

Dependent Claim 45 words

The method of claim 89, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 97

Dependent Claim 45 words

The method of claim 86, further including the step of detecting when the discharge per unit head Q 1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q 1 is increasing.

Claim 98

Dependent Claim 46 words

The method of claim 86, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.

Claim 99

Dependent Claim 54 words

The method of claim 86, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 100

Dependent Claim 36 words

The method of claim 86, further including the steps of: detecting the speed of rotation of the impeller N; detecting the torque T produced by turbine operation; and conducting said overriding control when dT/dt<0 and dN/dt<0.

Claim 101

Dependent Claim 43 words

The method of claim 86, further comprising the steps of: rapidly closing the wicket gates when it is detected that the ratio ∂Q 1 /∂N 1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.

Claim 102

Dependent Claim 54 words

The method of claim 86, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure P within the penstock; detecting the speed of rotation N of the impeller; and conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.

Claim 103

Dependent Claim 54 words

The method of claim 96, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of: detecting the hydraulic pressure p within the penstock; detecting the speed of rotation N of the impeller; and conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.

Claim 104

Dependent Claim 92 words

In a method of controlling wicket gates of a pump-turbine of the type showing during turbine operation the performance that discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, comprising the steps of: slowly opening said wicket gates upon removal of load from said pump-turbine; temporarily increasing the opening speed of said wicket gates during said slowly opening step when the pump-turbine is operated tracing the S-section in the Q 1 -reducing direction (dQ 1 /dt is negative).

Claim 105

Dependent Claim 92 words

In a method of controlling wicket gates of a pump-turbine of the type showing during turbine operation the performance that discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, comprising the steps of: slowly opening said wicket gates upon removal of load from said pump-turbine; temporarily increasing the opening speed of said wicket gates during said slowly opening step when the pump-turbine is operated tracing the S-section in the Q 1 -reducing direction (dQ 1 /dt is negative).

Claim 106

Dependent Claim 33 words

A method of controlling wicket gates as set forth in claim 98, wherein said opening speed increasing step is carried out when a fixed time period has elapsed after the removal of load.

Claim 107

Dependent Claim 48 words

A method of controlling wicket gates as set forth in claim 98, wherein said opening speed increasing step is carried out when number of rotation (N) of said pump-turbine and time lapse (t) after the removal of load satisfy the relationships, dN/dt<0 and d 2 N/dt 2 <0.

Claim 108

Dependent Claim 32 words

A method of controlling wicket gates as set forth in claim 4, wherein said wicket gates temporarily opening step is engaged when number of rotation of said pump-turbine attains a maximum value.

Claim 109

Independent Claim 131 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -reducing direction; and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only opening signals of a faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate, opening signals or closing signals from said regular controller gives an overriding opening signal of faster than or equal to said fixed rate.

Claim 110

Independent Claim 131 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -reducing direction; and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only opening signals of a faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate, opening signals or closing signals from said regular controller gives an overriding opening signal of faster than or equal to said fixed rate.

Claim 111

Independent Claim 130 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction; and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only closing signals of faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate closing signals or opening signals from said regular controller gives an overriding closing signal of faster than or equal to said fixed rate.

Claim 112

Independent Claim 130 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction; and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only closing signals of faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate closing signals or opening signals from said regular controller gives an overriding closing signal of faster than or equal to said fixed rate.

Claim 113

Dependent Claim 99 words

A method of controlling wicket gates as set forth in claim 102, further comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only closing signals of faster rate than a second fixed rate from said regular controller and, for any slower rate closing signals or opening signals from said regular controller, gives an overriding closing signal of faster than or equal to said second fixed rate.

Claim 114

Independent Claim 121 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -reducing direction, and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only substantially stopping or opening signals from a regular controller (such as a speed-governor) and, for any faster closing signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.

Claim 115

Independent Claim 121 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a condition where said pump-turbine is operating tracing said S-section in the Q 1 -reducing direction, and when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only substantially stopping or opening signals from a regular controller (such as a speed-governor) and, for any faster closing signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.

Claim 116

Independent Claim 123 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under an overriding control which allows only substantially stopping or closing signals from a regular controller (such as a speed-governor) and, for any faster opening signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.

Claim 117

Independent Claim 123 words

A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under an overriding control which allows only substantially stopping or closing signals from a regular controller (such as a speed-governor) and, for any faster opening signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.

Claim 118

Dependent Claim 89 words

A method of controlling wicket gates as set forth in claim 106, further comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only substantially stopping or closing signals from said regular controller and, for any faster opening signals from said regular controller, gives a second overriding signal for substantially holding at the current wicket gate position.

Claim 119

Dependent Claim 89 words

A method of controlling wicket gates as set forth in claim 102, further comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only substantially stopping or closing signals from said regular controller and, for any faster opening signals from said regular controller, gives a second overriding signal for substantially holding at the current wicket gate position.

Claim 120

Dependent Claim 97 words

A method of controlling wicket gates as set forth in claim 105, further comprising the steps of: detecting a second condition where said pump-turbine is operating tracing said S-section in the Q 1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only closing signals of faster rate than a fixed rate from said regular controller and, for any slower rate closing signals or opening signals from said regular controller, gives an overriding closing signal of faster than or equal to said fixed rate.

Claim 121

Dependent Claim 52 words

A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that both number of rotation (N) of said pump-turbine and hydraulic flow rate (Q) through said pump-turbine reduce with the lapse of time.

Claim 122

Dependent Claim 51 words

A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that, with the lapse of time, number of rotation (N) of said pump-turbine reduces and hydraulic pressure (P) in a penstock increases.

Claim 123

Dependent Claim 48 words

A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that both pump-turbine torque (T) and number of rotation (N) of said pump-turbine reduce with the lapse of time.

Claim 124

Dependent Claim 51 words

A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that number of rotation (N) of said pump-turbine and time lapse (t) satisfy the relationships, dN/dt<0 and d 2 N/dt 2 <0.

Claim 125

Dependent Claim 43 words

A method of controlling wicket gates as set forth in claim 102, 104 or 109, wherein said overriding control for closing is carried out when it is detected that hydraulic flow rate (Q) through said pump-turbine increases sharply with the lapse of time.

Claim 126

Dependent Claim 42 words

A method of controlling wicket gates as set forth in claim 102, 104 or 109, wherein said overriding control for closing is carried out when it is detected that, with the lapse of time, hydraulic pressure (P) in a penstock sharply reduces.

Claim 127

Dependent Claim 40 words

A method of controlling wicket gates as set forth in claim 98, further comprising the step of closing said wicket gates when it is detected that said pump-turbine operation tracing said S-section in the Q 1 -reducing direction is terminated.

Claim 128

Dependent Claim 50 words

A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that both number of rotation (N) of said pump-turbine and hydraulic flow rate (Q) through said pump-turbine reduce with the lapse of time.

Claim 129

Dependent Claim 49 words

A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that, with the lapse of time, number of rotation (N) of said pump-turbine reduces and hydraulic pressure (P) in a penstock increases.

Claim 130

Dependent Claim 47 words

A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that both the pump-turbine torque (T) and number of rotation (N) of said pump-turbine reduce with the lapse of time.

Claim 131

Dependent Claim 49 words

A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that number of rotation (N) of said pump-turbine and time lapse (t) satisfy the relationships, dN/dt<0 and d 2 N/dt 2 <0.

Claim 132

Dependent Claim 39 words

A method of controlling wicket gates as set forth in claim 102, 103 or 104, wherein said wicket gates closing and opening steps are carried out by forcibly controlling a hydraulic distributing valve of servomotors for the wicket gates.

Claim 133

Dependent Claim 146 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value to a negative value, out of said S-section.

Claim 134

Dependent Claim 146 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value to a negative value, out of said S-section.

Claim 135

Dependent Claim 146 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value to a negative value, out of said S-section.

Claim 136

Dependent Claim 146 words

In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (∂Q 1 /∂N 1 ) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, ∂Q 1 /∂N 1 , is once reversed from a positive value to a negative value, out of said S-section.

Claim 137

Dependent Claim 136 words

In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected in the Q 1 -reducing direction in the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, or tracing the S-section in the Q 1 -increasing direction, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.

Claim 138

Dependent Claim 136 words

In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q 1 ) and speed per unit head (N 1 ) satisfy the relationship, ∂Q 1 /∂N 1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected in the Q 1 -reducing direction in the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, or tracing the S-section in the Q 1 -increasing direction, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-05-09	1986-11-08	1987-05-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-05-09	1990-11-08	1991-05-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-05-09	1994-11-08	1995-05-10	$7700.00	Window Closed / Lapsed

Method of controlling wicket gates of a pump-turbine

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