US5847533A — Procedure and apparatus for braking a synchronous…

Claim 1

Independent Claim 96 words

A method for braking a synchronous motor having input connectors for the supply of a voltage into its stator windings, comprising the steps of: (a) determining whether braking is needed; and (b) if braking is needed, then connecting at least one braking resistor having a non-linear resistance characteristic to the input connectors of the synchronous motor, thereby closing the stator windings of the synchronous motor through the at least one braking resistor, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases as the voltage across the braking resistor increases.

Claim 2

Independent Claim 96 words

A method for braking a synchronous motor having input connectors for the supply of a voltage into its stator windings, comprising the steps of: (a) determining whether braking is needed; and (b) if braking is needed, then connecting at least one braking resistor having a non-linear resistance characteristic to the input connectors of the synchronous motor, thereby closing the stator windings of the synchronous motor through the at least one braking resistor, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases as the voltage across the braking resistor increases.

Claim 3

Dependent Claim 39 words

The method as defined in claim 1, wherein the synchronous motor is fed by a frequency converter having an intermediate circuit, and further wherein said step (b) connects the braking resistor to the intermediate circuit of the frequency converter.

Claim 4

Dependent Claim 26 words

The method as defined in claim 1, further comprising the step of (c) shortcircuiting the stator windings when the speed of the motor is substantially zero.

Claim 5

Dependent Claim 37 words

The method as defined in claim 3, wherein the motor is magnetized with permanent magnets, and further wherein said step (b) connects the braking resistor by closing a switch controlled by the electromotive force of the motor.

Claim 6

Dependent Claim 31 words

The method as defined in claim 3, wherein the short-circuiting of said step (c) causes the braking resistor to no longer be connected to the input connectors of the synchronous motor.

Claim 7

Dependent Claim 24 words

The method as defined in claim 1, wherein said step (b) connects the at least one braking resistor by closing at least one switch.

Claim 8

Dependent Claim 26 words

The method as defined in claim 1, wherein the non-linear resistance characteristic is such that a resistance value of the braking resistor increases with increased temperature.

Claim 9

Dependent Claim 27 words

The method as defined in claim 1, wherein the motor is an elevator motor, and said step (b) slows an elevator car controlled by the elevator motor.

Claim 10

Independent Claim 106 words

An apparatus for braking a synchronous motor provided with input connectors for the supply of a voltage into the motor's stator windings, said apparatus comprising: at least one braking resistor having a non-linear resistance characteristic, said at least one braking resistor being selectively connected to the input connectors of the synchronous motor; and at least one switch for selectively connecting said at least one braking resistor to the input connectors such that the stator windings of the synchronous motor can be closed, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases as the voltage across said braking resistor increases.

Claim 11

Independent Claim 106 words

An apparatus for braking a synchronous motor provided with input connectors for the supply of a voltage into the motor's stator windings, said apparatus comprising: at least one braking resistor having a non-linear resistance characteristic, said at least one braking resistor being selectively connected to the input connectors of the synchronous motor; and at least one switch for selectively connecting said at least one braking resistor to the input connectors such that the stator windings of the synchronous motor can be closed, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases as the voltage across said braking resistor increases.

Claim 12

Dependent Claim 39 words

The apparatus as defined in claim 9, further comprising a frequency converter provided with an intermediate circuit having d.c. conductors, said at least one braking resistor and said switch being mounted between the d.c. conductors of said intermediate circuit.

Claim 13

Dependent Claim 31 words

The apparatus as defined in claim 10, further comprising a second switch connected in parallel with said at least one braking resistor for selectively short-circuiting the stator windings of the motor.

Claim 14

Dependent Claim 26 words

The apparatus as defined in claim 10, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases with increased temperature.

Claim 15

Dependent Claim 28 words

The apparatus as defined in claim 9, wherein the synchronous motor is magnetized with permanent magnets, and said switch is controlled by the electromotive force of the motor.

Claim 16

Dependent Claim 34 words

The apparatus as defined in claim 9, wherein said motor is an elevator motor and said switch selectively connects said braking resistor in order to slow an elevator car controlled by the elevator motor.

Claim 17

Dependent Claim 26 words

The apparatus as defined in claim 9, wherein the non-linear resistance characteristic is such that a resistance value of said braking resistor increases with increased temperature.

Claim 18

Dependent Claim 44 words

The apparatus as defined in claim 9, further comprising: a second braking resistor connected in series with said braking resistor and in parallel with said switch; and a second switch for selectively connecting said second braking resistor to the input connectors of the motor.

Claim 19

Dependent Claim 14 words

The apparatus as defined in claim 16, wherein said second switch is a transistor.

Claim 20

Independent Claim 145 words

A method for braking a synchronous motor having input connectors for the supply of a voltage into its stator windings, comprising the steps of: (a) determining whether braking is needed; and (b) if braking is needed, then connecting at least one braking resistor having a non-linear resistance characteristic to the input connectors of the synchronous motor, thereby closing the stator windings of the synchronous motor through the at least one braking resistor, wherein said step (b) connects the at least one braking resistor by closing at least one switch, and wherein there are a plurality of the braking resistors equal in number to the number of input connectors of the motor, the plurality of braking resistors being arranged in a star configuration, and further wherein said step (b) connects a respective one of the three braking resistors to a respective pair of the input connectors.

Claim 21

Independent Claim 145 words

A method for braking a synchronous motor having input connectors for the supply of a voltage into its stator windings, comprising the steps of: (a) determining whether braking is needed; and (b) if braking is needed, then connecting at least one braking resistor having a non-linear resistance characteristic to the input connectors of the synchronous motor, thereby closing the stator windings of the synchronous motor through the at least one braking resistor, wherein said step (b) connects the at least one braking resistor by closing at least one switch, and wherein there are a plurality of the braking resistors equal in number to the number of input connectors of the motor, the plurality of braking resistors being arranged in a star configuration, and further wherein said step (b) connects a respective one of the three braking resistors to a respective pair of the input connectors.

Claim 22

Dependent Claim 37 words

The method as defined in claim 18, wherein there are exactly three of the braking resistors and exactly three of the switches, and said step (b) controls the three switches such that they open and close together.

Claim 23

Independent Claim 134 words

An apparatus for braking a synchronous motor provided with input connectors for the supply of a voltage into the motor's stator windings, said apparatus comprising: at least one braking resistor having a non-linear resistance characteristic, said at least one braking resistor being selectively connected to the input connectors of the synchronous motor; and at least one switch for selectively connecting said at least one braking resistor to the input connectors such that the stator windings of the synchronous motor can be closed, wherein there are a plurality of said braking resistors equal in number to the number of input connectors of the motor, said plurality of braking resistors being arranged in a star configuration such that a respective one of said braking resistors is selectively connected between a respective pair of the input connectors.

Claim 24

Independent Claim 134 words

An apparatus for braking a synchronous motor provided with input connectors for the supply of a voltage into the motor's stator windings, said apparatus comprising: at least one braking resistor having a non-linear resistance characteristic, said at least one braking resistor being selectively connected to the input connectors of the synchronous motor; and at least one switch for selectively connecting said at least one braking resistor to the input connectors such that the stator windings of the synchronous motor can be closed, wherein there are a plurality of said braking resistors equal in number to the number of input connectors of the motor, said plurality of braking resistors being arranged in a star configuration such that a respective one of said braking resistors is selectively connected between a respective pair of the input connectors.

Claim 25

Dependent Claim 22 words

The apparatus as defined in claim 20, wherein there are exactly three of said braking resistors and exactly three of said switches.

Claim 26

Dependent Claim 20 words

The apparatus as defined in claim 21, wherein said three switches are controlled such that they open and close together.

Claim 27

Independent Claim 80 words

A method for braking a motor having stator windings, the method comprising the steps of: (a) supplying power to the motor in order to drive the motor; (b) determining when braking of the motor is needed; (c) connecting, when said step (b) determines that braking is needed, at least one braking resistor across the stator windings, the braking resistor having a resistance characteristic such that a rise in voltage across the braking resistor increases the resistance of the braking resistor.

Claim 28

Independent Claim 80 words

A method for braking a motor having stator windings, the method comprising the steps of: (a) supplying power to the motor in order to drive the motor; (b) determining when braking of the motor is needed; (c) connecting, when said step (b) determines that braking is needed, at least one braking resistor across the stator windings, the braking resistor having a resistance characteristic such that a rise in voltage across the braking resistor increases the resistance of the braking resistor.

Claim 29

Dependent Claim 31 words

The method as defined in claim 23, wherein said step (b) determines that braking is needed in response to a break in the power supplied to the motor in step (a).

Claim 30

Dependent Claim 49 words

The method as defined in claim 23, wherein the motor is an elevator motor mechanically linked to an elevator car, and said step (b) includes detecting an overspeed condition of the elevator car and determining that braking is needed when the overspeed condition of the elevator car is detected.

Claim 31

Dependent Claim 16 words

The method as defined in claim 23, wherein the resistance characteristic is a non-linear voltage-current characteristic.

Claim 32

Dependent Claim 28 words

The method as defined in claim 23, wherein the resistance characteristic is non-linear and is such that a rise in temperature increases the resistance of the braking resistance.

Claim 33

Dependent Claim 38 words

The method as defined in claim 23, wherein a plurality of the braking resistors are connected in series, and said step (c) selectively connects or short-circuits the braking resistors individually as the speed of the elevator car changes.

Claim 34

Dependent Claim 14 words

The method as defined in claim 23, wherein the motor is a synchronous motor.

Claim 35

Dependent Claim 28 words

The method as defined in claim 29, wherein the synchronous motor is mechanically liked to an elevator car such that said step (a) moves the elevator car up/down.

Claim 36

Independent Claim 83 words

A method for minimizing sink speed of an elevator car driven by a synchronous motor, said method comprising: (a) connecting a first braking resistance across stators of the synchronous motor when the elevator car is being braked from a first speed; and (b) connecting a second braking resistance across the stators when the elevator car is being braked from a second speed, the second speed being slower than the first speed, wherein the second braking resistance is lower than the first braking resistance.

Claim 37

Independent Claim 83 words

A method for minimizing sink speed of an elevator car driven by a synchronous motor, said method comprising: (a) connecting a first braking resistance across stators of the synchronous motor when the elevator car is being braked from a first speed; and (b) connecting a second braking resistance across the stators when the elevator car is being braked from a second speed, the second speed being slower than the first speed, wherein the second braking resistance is lower than the first braking resistance.

Claim 38

Dependent Claim 42 words

The method as defined in claim 31, wherein the same resistor is used for the first and second braking resistances, and a voltage across the resistor is higher at the first speed than the voltages across the resistor at the second speed.

Claim 39

Dependent Claim 33 words

The method as defined in claim 31, wherein said step (b) is performed when the elevator car is released from a stopped state and no power is being supplied to the synchronous motor.

Claim 40

Independent Claim 102 words

A method for braking an elevator car mechanically linked to an elevator motor having stator windings, the method comprising the steps of: (a) moving the elevator car by supplying power to the motor; (b) determining when braking of the moving elevator car is needed; (c) connecting, when said step (b) determines that braking is needed, a braking resistance across the stator windings, the braking resistance having a non-linear resistance characteristic, wherein the braking resistance includes a plurality of series-connected resistors, and the non-linear characteristic is accomplished by selectively connecting or short-circuiting the individual resistors as the speed of the elevator car changes.

Claim 41

Independent Claim 102 words

A method for braking an elevator car mechanically linked to an elevator motor having stator windings, the method comprising the steps of: (a) moving the elevator car by supplying power to the motor; (b) determining when braking of the moving elevator car is needed; (c) connecting, when said step (b) determines that braking is needed, a braking resistance across the stator windings, the braking resistance having a non-linear resistance characteristic, wherein the braking resistance includes a plurality of series-connected resistors, and the non-linear characteristic is accomplished by selectively connecting or short-circuiting the individual resistors as the speed of the elevator car changes.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-12-07	2002-06-08	2002-12-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-12-07	2006-06-08	2006-12-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-12-07	2010-06-08	2010-12-08	$7700.00	Window Closed / Lapsed

Procedure and apparatus for braking a synchronous motor

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