Drive circuit for electric motors
AssigneeRegal Beloit America, Inc.
InventorsLudovic Andre Chretien, Paul Bryan Snipes
Life of this patent
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Abstract
A method of operating a drive circuit for parallel electric motors is provided. The method includes receiving measurements of stator phase currents in the parallel electric motors. The method includes selecting a target PM motor, from among the parallel electric motors, that generates a largest torque output. The method includes executing a vector control algorithm to generate a complex command voltage vector for the target PM motor. The method includes generating and transmitting a pulse width modulation (PWM) signal based on the complex command voltage vector for controlling an inverter. The method includes operating the inverter according to the PWM signal to supply three-phase alternating current (AC) power to the parallel electric motors.
Claims24
A method of operating a drive circuit for parallel electric motors, at least one of which is a permanent magnet (PM) motor, said method comprising:
- receiving measurements of stator phase currents in the parallel electric motors;
- selecting a target PM motor, from among the parallel electric motors, that generates a largest torque output;
- executing a vector control algorithm to generate a complex command voltage vector for the target PM motor;
- generating and transmitting a pulse width modulation (PWM) signal based on the complex command voltage vector for controlling an inverter;
- and
- operating the inverter according to the PWM signal to supply three-phase alternating current (AC) power to the parallel electric motors.
A drive circuit for parallel electric motors, at least one of which is a permanent magnet (PM) motor, said drive circuit comprising:
- an inverter coupled to the parallel electric motors and configured to supply an alternating current (AC) signal to stator windings thereof based on a PWM signal;
- and
- a digital signal processor (DSP) coupled to said inverter and configured to:
- receive respective stator phase current measurements for the parallel electric motors;
- select a target PM motor, of the parallel electric motors, having a largest torque output among the parallel electric motors;
- execute a vector control algorithm to generate a complex command voltage vector for the target PM motor;
- generate the PWM signal based on the complex command voltage vector for the target PM motor;
- and
- transmit the PWM signal to said inverter to operate said inverter and supply the AC signal to the stator windings of the parallel electric motors.
A system, comprising:
- a first three-phase motor configured to drive a load;
- an inverter coupled to said first three-phase motor and configured to supply a three-phase output power thereto;
- an induction motor configured to drive the load, and further configured to be selectively coupled in parallel to said first three-phase motor and said inverter;
- a three-phase AC line-frequency bus configured to be selectively coupled to said induction motor;
- and
- a digital signal processor (DSP) coupled to said inverter and configured to:
- selectively, when in a direct operating mode, couple said induction motor to said three-phase AC line-frequency bus, and decouple said induction motor from said first three-phase motor and said inverter;
- selectively, when in a parallel operating mode, couple said induction motor to said inverter, and decouple said induction motor from said three-phase AC line-frequency bus;
- control said inverter to supply the three-phase output power from said inverter to said first three-phase motor;
- and
- control said inverter to supply the three-phase output power from said inverter to said induction motor when in the parallel operating mode.
A method of controlling fluid flow generated by fluid-moving equipment driven by a plurality of motors, said method comprising:
- receiving a fluid flow demand signal indicating an amount of fluid flow commanded to be output by the fluid-moving equipment driven by the plurality of motors;
- determining a state of operation, of a plurality of predefined states of operation, in which to operate a drive circuit coupled to the plurality of motors to generate the commanded amount of fluid flow;
- adjusting at least one relay associated with at least one motor of the plurality of motors to activate and selectively couple the at least one motor to an inverter or an AC line-frequency power according to the determined state of operation;
- and
- adjusting operation of the inverter to generate the commanded amount of fluid flow.
Dependencies are inferred from the claim text.