A current controller and method for a DC motor

Claim 2

A current controller including: modulating means (6) for which employs a pulse width modulation signal having a first period with which a current change is periodically repeated and in which a plurality of pulses with a second period are included, for modulating a current within said first period by said pulse width modulation signal; detection means (5, 11) for detecting a current in a load at least once within said second period; and means (16) for producing said pulse width modulation signal in accordance with a current flow rate in order to make said detected current agree with a command value; characterized in that said current controller further comprises; assumed response generating means (13) for generating an assumed response (17) as a current response within said first period in accordance with a command current; and load model means (151) for finding said current flow rate in accordance with an initial value (151) stored in a readable and writable memory element in order to flow a current corresponding to said assumed response means (15) for modifying the initial value of said load model means in accordance with the difference between said detected current and said assumed response output, and generating the necessary current flow rate at said second period as time elapses after the start of said first period.

Claim 3

A current controller for motors including; a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response as a current response within said commutation period in accordance with the command current; and motor model means (125) for finding said current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and generating the necessary flow rate at said pulse width modulation period as time elapses after the start of the commutation period.

Claim 4

A current controller for motors including; a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response as a current response within said commutation period in accordance with the command current; and motor model means (125) for finding said current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and generating the necessary flow rate at said pulse width modulation period as time elapses after the start of the commutation period.

Claim 5

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (31) for generating the pulse width modulation signal according to a flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and numerical formula based motor model means (125) for generating an control output associated with a motor current in accordance with said assumed response and the initial value stored in a readable and writable memory element, modifying means for generating the flow rate as said control output in accordance with the output of said motor model means which changes as time elapses after the commutation within said commutation period, and modifying after the end of said commutation period the initial value of said motor model means in accordance with the difference between a sequence of current detected values detected within said finished commutation period and a sequence of assumed responses at the time when said control output is produced within the finished commutation period.

Claim 6

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (31) for generating the pulse width modulation signal according to a flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and numerical formula based motor model means (125) for generating an control output associated with a motor current in accordance with said assumed response and the initial value stored in a readable and writable memory element, modifying means for generating the flow rate as said control output in accordance with the output of said motor model means which changes as time elapses after the commutation within said commutation period, and modifying after the end of said commutation period the initial value of said motor model means in accordance with the difference between a sequence of current detected values detected within said finished commutation period and a sequence of assumed responses at the time when said control output is produced within the finished commutation period.

Claim 7

A current controller for motors including: a motor (21); a pulse width modulation inverted (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; motor model means (125) for finding a current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response modifying means for modifying said current flow rate in accordance with the difference between said detected current and said assumed response modifying means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response, generating the necessary current flow rate as time elapses after commutation in turn; and modifying means for modifying said generated flow rate in accordance with the difference between the just previously detected current value and the assumed response value associated with said detected current.

Claim 8

A current controller for motors including: a motor (21); a pulse width modulation inverted (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting the current a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; motor model means (125) for finding a current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response modifying means for modifying said current flow rate in accordance with the difference between said detected current and said assumed response modifying means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response, generating the necessary current flow rate as time elapses after commutation in turn; and modifying means for modifying said generated flow rate in accordance with the difference between the just previously detected current value and the assumed response value associated with said detected current.

Claim 9

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (125) for finding the current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response and at least one parameter (1252) relating to the amount of change of the current flow rate changing within said commutation period; and means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response, modifying said parameter in accordance with the changed pattern within one commutation period of said detected current and the changed pattern within the commutation period of said assumed response, and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 10

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (125) for finding the current flow rate in accordance with an initial value (1251) stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response and at least one parameter (1252) relating to the amount of change of the current flow rate changing within said commutation period; and means for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response, modifying said parameter in accordance with the changed pattern within one commutation period of said detected current and the changed pattern within the commutation period of said assumed response, and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 11

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (125) for generating the flow rate necessary for flowing a motor current corresponding to said assumed response by calculating a parameter (12562, 12563) stored in at least one readable and writable memory element from an initial value (12561) stored in a readable and writable memory element calculator means (12560) for calculating said initial value (12561) and said parameter (12562, 12563); and means for modifying said initial value in accordance with the integrated value of the difference between said detected current and said assumed response, modifying the parameter on the basis of the current response state, and generating the current flow rate in turn by calculating the initial value and said parameter as time elapses after the commutation.

Claim 12

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller further comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (125) for generating the flow rate necessary for flowing a motor current corresponding to said assumed response by calculating a parameter (12562, 12563) stored in at least one readable and writable memory element from an initial value (12561) stored in a readable and writable memory element calculator means (12560) for calculating said initial value (12561) and said parameter (12562, 12563); and means for modifying said initial value in accordance with the integrated value of the difference between said detected current and said assumed response, modifying the parameter on the basis of the current response state, and generating the current flow rate in turn by calculating the initial value and said parameter as time elapses after the commutation.

Claim 13

A controller including: calculator means (70) having a first period in which an control output is calculated, and a second period in which a plurality of control output are produced within said first period, and making calculation within said first period to determine a series of value of control output; output means (706) for producing an amount of control during said second period; and at least one readable and writable memory element for storing a parameter associated with said value of control output; characterized in that said controller further comprises: two pattern tables (7051A, 7051B) each formed of a plurality of readable and writable memory elements; and means for modifying the parameter associated with the value of control output of the n-th period in said first period before at least the (n-2)-th period, calculating, control output produced at said second period in the n-th period, within the (n-1)-th period, storing said control output in one of said two pattern tables, and producing amounts of control associated with the (n-1)-th period from the other pattern table in which said control output are stored, within the (n-2)-­th period of said first period at each said second period.

Claim 14

A controller including: calculator means (70) having a first period in which an control output is calculated, and a second period in which a plurality of control output are produced within said first period, and making calculation within said first period to determine a series of value of control output; output means (706) for producing an amount of control during said second period; and at least one readable and writable memory element for storing a parameter associated with said value of control output; characterized in that said controller further comprises: two pattern tables (7051A, 7051B) each formed of a plurality of readable and writable memory elements; and means for modifying the parameter associated with the value of control output of the n-th period in said first period before at least the (n-2)-th period, calculating, control output produced at said second period in the n-th period, within the (n-1)-th period, storing said control output in one of said two pattern tables, and producing amounts of control associated with the (n-1)-th period from the other pattern table in which said control output are stored, within the (n-2)-­th period of said first period at each said second period.

Claim 15

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (70) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; characterized in that said motor model means comprises: two current flow rate pattern tables (7051A, 7051B) each formed of a plurality of readable and writable memory elements and which store the flow rates of the pulse width modulation signal within said commutation in turn; and means having at least two initial values (701A, 701B) of said motor model means, and which modifies the initial value of the motor model means in the n-th commutation period in accordance with the difference between said detected current and said assumed response before at least the (n-2)-th commutation period, stores the output from said motor model means in accordance with the time lapse after the commutation due to said initial value within the (n-1)-­th commutation period, in one of said two flow rate pattern tables, and producing the flow rates associated with the (n-1)-th commutation period from the other flow rate pattern table in which said current flow rates are stored within the (n-2)-th commutation period at each output of said pulse width modulated signal.

Claim 16

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; and motor model means (70) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; characterized in that said motor model means comprises: two current flow rate pattern tables (7051A, 7051B) each formed of a plurality of readable and writable memory elements and which store the flow rates of the pulse width modulation signal within said commutation in turn; and means having at least two initial values (701A, 701B) of said motor model means, and which modifies the initial value of the motor model means in the n-th commutation period in accordance with the difference between said detected current and said assumed response before at least the (n-2)-th commutation period, stores the output from said motor model means in accordance with the time lapse after the commutation due to said initial value within the (n-1)-­th commutation period, in one of said two flow rate pattern tables, and producing the flow rates associated with the (n-1)-th commutation period from the other flow rate pattern table in which said current flow rates are stored within the (n-2)-th commutation period at each output of said pulse width modulated signal.

Claim 17

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller for motor further comprises: altering means for altering the on or off time of the pulse width modulation signal in asynchronism with the pulse width modulation signal period; and calculator means for permitting the on or off time of the pulse width modulation signal to agree with said commutation at each commutation at which the previous commutation period ends and the next commutation period starts, and determining the current flow rate in accordance with the difference between said command current and said detected current.

Claim 18

A current controller for motors including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said current controller for motor further comprises: altering means for altering the on or off time of the pulse width modulation signal in asynchronism with the pulse width modulation signal period; and calculator means for permitting the on or off time of the pulse width modulation signal to agree with said commutation at each commutation at which the previous commutation period ends and the next commutation period starts, and determining the current flow rate in accordance with the difference between said command current and said detected current.

Claim 19

A calculator unit including: a calculator element; a counting element which increments or decrements in accordance with the change of an input signal; a readable and writable memory element for storing a numerical value; and determining means for determining either one of the two output states in accordance with the comparison between the contents of said counting element (1005) and said memory element (1006); characterized in that said calculator unit further comprises: a signal control element (1002, 1007) for generating an initialized signal in accordance with the change of a signal from the external or a signal from the calculator unit; and means (104) for reset the value of said counting element into an arbitrary value by said initializing signal.

Claim 20

A calculator unit including: a calculator element; a counting element which increments or decrements in accordance with the change of an input signal; a readable and writable memory element for storing a numerical value; and determining means for determining either one of the two output states in accordance with the comparison between the contents of said counting element (1005) and said memory element (1006); characterized in that said calculator unit further comprises: a signal control element (1002, 1007) for generating an initialized signal in accordance with the change of a signal from the external or a signal from the calculator unit; and means (104) for reset the value of said counting element into an arbitrary value by said initializing signal.

Claim 21

A motor system including: a pulse width modulation inverter (20) for flowing a current in an armature winding (211); modulation means (26) for modulating said commutation period by a pulse width modulation signal having a plurality of pulses within the commutation period in which said current is changed in its direction; means (5, 11) for detecting the current (720) a plurality of times within said commutation period; and means (16) for generating a pulse width modulation output in accordance with a current flow rate in order to make said detected current coincident with a command current; characterized in that said motor system comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; motor model means (125) for finding the current flow rate in accordance with an initial value stored in a readable and writable memory element in order to flow a winding current corresponding to said assumed response; and current control means for modifying the initial value of said motor model means in accordance with said detected current and said assumed response, and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 22

A motor system including: a pulse width modulation inverter (20) for flowing a current in an armature winding (211); modulation means (26) for modulating said commutation period by a pulse width modulation signal having a plurality of pulses within the commutation period in which said current is changed in its direction; means (5, 11) for detecting the current (720) a plurality of times within said commutation period; and means (16) for generating a pulse width modulation output in accordance with a current flow rate in order to make said detected current coincident with a command current; characterized in that said motor system comprises: assumed response generating means (123) for generating an assumed response (17) as a current response within said commutation period in accordance with the command current; motor model means (125) for finding the current flow rate in accordance with an initial value stored in a readable and writable memory element in order to flow a winding current corresponding to said assumed response; and current control means for modifying the initial value of said motor model means in accordance with said detected current and said assumed response, and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 23

A compressor system including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said compressor system further comprises: assumed response generating means (123) for motor which generates an assumed response (17) as a current response within said commutation period in accordance with said command current; motor model means (125) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; and a current controller for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 24

A compressor system including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means (26) for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said compressor system further comprises: assumed response generating means (123) for motor which generates an assumed response (17) as a current response within said commutation period in accordance with said command current; motor model means (125) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; and a current controller for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 25

An air blower system including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said air blower system comprises: assumed response generating means (123) for motor which generates an assumed response (17) as a current response within said commutation period in accordance with said command current; motor model means (125) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; and a current controller for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 26

An air blower system including: a motor (21); a pulse width modulation inverter (20) for driving said motor; modulating means for modulating a commutation period by a pulse width modulation signal having a plurality of pulses within said commutation period in which the direction of current to said motor is changed; detection means (5, 11) for detecting a current (720) a plurality of times within said commutation period; and means (16) for generating the pulse width modulation signal according to a current flow rate in order to make said detected current agree with a command current; characterized in that said air blower system comprises: assumed response generating means (123) for motor which generates an assumed response (17) as a current response within said commutation period in accordance with said command current; motor model means (125) for finding the current flow rate in accordance with the initial value stored in a readable and writable memory element in order to flow a motor current corresponding to said assumed response; and a current controller for modifying the initial value of said motor model means in accordance with the difference between said detected current and said assumed response and sequentially generating the necessary flow rate as time elapses after the commutation.

Claim 27

A current control method including: a load (3); an inverter (4) for driving said load; modulation means (6) for pulse width modulating said inverter at each predetermined period to make a plurality of pulses modulated present within each of these periods; load current detecting means (5, 11) for detecting a load current at least once within the period of the modulated pulses; and means (12, 13, 15) for adjusting the modulation frequency of said pulse width modulation in accordance with the difference between the load current obtained by said load current detecting means and the current command value for driving said load in a desired state; characterized in that said current control method comprises the step of adjusting the pulse width modulated state within said period on the basis of the difference between it and the load current detected value so as to match the most satisfactory load driving state characteristic which is determined by the current command value, and the torque and inertia of the load.

Claim 28

A current control method including: a load (3); an inverter (4) for driving said load; modulation means (6) for pulse width modulating said inverter at each predetermined period to make a plurality of pulses modulated present within each of these periods; load current detecting means (5, 11) for detecting a load current at least once within the period of the modulated pulses; and means (12, 13, 15) for adjusting the modulation frequency of said pulse width modulation in accordance with the difference between the load current obtained by said load current detecting means and the current command value for driving said load in a desired state; characterized in that said current control method comprises the step of adjusting the pulse width modulated state within said period on the basis of the difference between it and the load current detected value so as to match the most satisfactory load driving state characteristic which is determined by the current command value, and the torque and inertia of the load.

Claim 29

A current control method according to claim 14, wherein said most satisfactory load driving state is the load starting state, and the pulse width modulated state within said period is adjusted on the basis of the difference between the load current detected value detected in a period before said period, and the current command value.

Claim 30

A current controlling apparatus including: modulation means having a first period in which a load current repeats a rising, for modulating during a second period a current flowing within said first period with a pulse-width modulation signal having a plurality of pulses within said first period; and means for detecting a load current several times within said first period, characterized by comprising: means for storing data related to a current detection value previously provided within said first period and a current conduction rate of the pulse-width modulation signal at the time of current detection; means for presuming a load state from the stored data; means responsive to the load state presumed by said presuming means for generating a train of pulse­width modulation signals which are outputted within said first period.

Claim 31

A current controlling apparatus including: modulation means having a first period in which a load current repeats a rising, for modulating during a second period a current flowing within said first period with a pulse-width modulation signal having a plurality of pulses within said first period; and means for detecting a load current several times within said first period, characterized by comprising: means for storing data related to a current detection value previously provided within said first period and a current conduction rate of the pulse-width modulation signal at the time of current detection; means for presuming a load state from the stored data; means responsive to the load state presumed by said presuming means for generating a train of pulse­width modulation signals which are outputted within said first period.

Claim 32

A current controlling apparatus including: modulation means having a first period in which a load current repeats a rising, for modulating said first period with a pulse-width modulation signal having a second period in which plurality of periods are included within said first period; and means for detecting a load current several times within said first period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said first period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a constant current rise; means for presuming a load state from the stored data; means responsive to the load state presumed by said presuming means for generating a train of pulse­width modulation signals which are outputted within said first period; means for detecting a difference between the data related to the current detection value previously provided within said first period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and means for generating a train of pulse-width modulation signals which are outputted within said first period and obtained from said modified data in sychronization with said first period.

Claim 33

A current controlling apparatus including: modulation means having a first period in which a load current repeats a rising, for modulating said first period with a pulse-width modulation signal having a second period in which plurality of periods are included within said first period; and means for detecting a load current several times within said first period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said first period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a constant current rise; means for presuming a load state from the stored data; means responsive to the load state presumed by said presuming means for generating a train of pulse­width modulation signals which are outputted within said first period; means for detecting a difference between the data related to the current detection value previously provided within said first period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and means for generating a train of pulse-width modulation signals which are outputted within said first period and obtained from said modified data in sychronization with said first period.

Claim 34

An air-conditioning apparatus including: a compressor; a motor for driving said compressor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals which are outputted within said commutation period and obtained from said modified data in sychronization with said first period.

Claim 35

An air-conditioning apparatus including: a compressor; a motor for driving said compressor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals which are outputted within said commutation period and obtained from said modified data in sychronization with said first period.

Claim 36

A fan apparatus including: a motor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals which are outputted within said commutation period and obtained from said modified data.

Claim 37

A fan apparatus including: a motor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within said commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals which are outputted within said commutation period and obtained from said modified data.

Claim 38

An air cleaner including: a motor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within the commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals hich are outputted within said commutation period and obtained from said modified data.

Claim 39

An air cleaner including: a motor; a pulse-width modulation inverter for driving said motor; modulation means for modulating a commutation period with a pulse-width modulation signal having a plurality of pulses within said commutation period in which a current conduction direction of said motor is changed; and means for detecting a current several times within said commutation period, characterized by comprising: first memory means for storing data related to a current detection value previously provided within the commutation period and a current conduction rate of the pulse-width modulation signal at the time of current detection; second memory means for storing data related to a current rise; means for detecting a difference between the data related to the current detection value previously provided within said commutation period which is stored by said first memory means and the data related to the current which is stored by said second memory means; means responsive to the detected difference for modifying the data related to the current conduction rate of said stored previous pulse-width modulation signal; and current control means for generating a train of pulse-width modulation signals hich are outputted within said commutation period and obtained from said modified data.