ELECTRICAL MACHINE HAVING A SERIES CHOPPER CIRCUIT

Abstract

A controller and a motor assembly having a controller. The controller includes a first switch assembly in a series configuration with the motor, where the first switch assembly has a first transistor, a second switch assembly in a parallel configuration with the motor, where the second switch assembly has a second transistor, and a control circuit electrically connected to the first transistor and to the second transistor to control the first switch assembly and the second switch assembly to provide a chopped voltage to a motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial block diagram, partial side view of an electrical machine having a motor coupled to a controller.

FIG. 2 is a block diagram of the controller of FIG. 1.

FIG. 3 is a circuit schematic of the controller of FIG. 1.

FIG. 4 is a partial block diagram, partial circuit schematic of the machine of FIG. 1.

FIG. 5A is an illustration of motor voltage with the prior art triac control.

FIG. 5B is an illustration of motor voltage generated by the controller of FIG. 1.

FIG. 6 is a block diagram of an alternate chopper control circuit.

FIG. 7 is a circuit schematic of the block diagram shown FIG. 6.

Claims

1. A controller for controlling an electric motor, the controller comprising: a first switch assembly connectable in a series configuration with the motor, the first switch assembly having a first transistor configured to control the first switch assembly at least between a first state and a second state;a second switch assembly connectable in a parallel configuration with the motor, the second switch assembly having a second transistor configured to control the second switch assembly at least between the first state and the second state; anda control circuit electrically connected to the first transistor and to the second transistor to control the first switch assembly and the second switch assembly, respectively, the control circuit configured to control the first and second switch assemblies for providing a chopped voltage to the motor.

2. The controller of claim 1, wherein at least one of the first switch assembly and the second switch assembly is configured to be a bidirectional switching element.

3. The controller of claim 1, wherein the first transistor and the second transistor include at least one of a snubbered IGBT element and a MOSFET.

4. The controller of claim 1, wherein at least one of the first switch assembly and the second switch assembly includes a set of four diodes in a full-wave rectifier configuration.

5. The controller of claim 4, wherein at least one of the first switch assembly and the second switch assembly includes a sensor to detect a current supplied to the motor.

6. The controller of claim 1, wherein the control circuit is operable to supply a speed command to control the first switch assembly and the second switch assembly, and includes at least one of an EMI filter, a power supply, a driver circuit, a current limiter, a deadband generator, an under-voltage lockout circuit, and a PWM generator.

7. The controller of claim 1, wherein the control circuit includes a low voltage circuit, a power line circuit, an isolator barrier to at least partially separate the power line circuit and the low voltage circuit, and external controls.

8. The controller of claim 7, wherein the power line circuit is operable to relay power from a power line to the motor and includes at least one of an EMI filter, a driver circuit, and a first power supply.

9. The controller of claim 7, wherein the low voltage circuit includes at least one of a current limiter, a deadband generator, a PWM generator, and under-voltage lockout circuit, a PWM to DC converter circuit, and a second power supply, and wherein the low voltage circuit interacts with the external controls to receive at least one of a DC voltage to operate the low voltage circuit and a speed command to operate the motor.

10. A controller operable to control a motor, the controller comprising: a first switch assembly configured in a series arrangement with the motor, the first switch assembly including a sensor to detect a characteristic of the power supplied to the motor and a first MOSFET operable to control the first switch assembly between a first state and a second state;a second switch assembly configured in a parallel arrangement with the motor, the second switch assembly including a second MOSFET operable to control the second switch assembly between the first state and the second state; anda control circuit operable to control the first MOSFET to switch the first switch assembly from the first state to the second state, and the second MOSFET to switch the second switch assembly from the second state to the first state to provide a chopped voltage to the motor.

11. The controller of claim 10, wherein at least one of the first switch assembly and the second switch assembly includes a set of four diodes in a full-wave rectifier configuration.

12. The controller of claim 10, wherein the control circuit is operable to generate a speed command to control the motor, and includes at least one of an EMI filter, a power supply, a driver circuit, a current limiter, a deadband generator, an under-voltage lockout circuit, and a PWM generator.

13. The controller of claim 10, wherein the control circuit includes a low voltage circuit, a power line circuit, an isolator barrier at least partially separating the low voltage circuit and the power line circuit, and external controls coupled to the low voltage circuit, the external controls operable to receive a DC voltage and a speed command to control the motor.

14. The controller of claim 13, wherein the power line circuit is operable to relay power from a power line to the motor and includes at least one of an EMI filter, a driver circuit, and a first power supply.

15. The controller of claim 13, wherein the low voltage circuit includes at least one of a current limiter, a deadband generator, a PWM generator, under-voltage lockout circuit, a PWM to DC converter circuit, and a second power supply.

16. A motor assembly comprising: an electric motor; anda controller operable to control the electric motor, the controller including a first switch assembly connectable in a series configuration with the electric motor, the first switch assembly having a first transistor configured to control the first switch assembly at least between a first state and a second state;a second switch assembly connectable in a parallel configuration with the electric motor, the second switch assembly having a second transistor configured to control the second switch assembly at least between the first state and the second state; anda control circuit electrically connected to the first transistor and to the second transistor to control the first switch assembly and the second switch assembly, respectively, the control circuit configured to control the first and second switch assemblies to provide a chopped voltage to the electric motor.

17. The motor assembly of claim 16, wherein the first transistor and the second transistor include at least one of a snubbered IGBT element and a MOSFET.

18. The motor assembly of claim 16, wherein at least one of the first switch assembly and the second switch assembly includes a set of four diodes in a full-wave rectifier configuration.

19. The motor assembly of claim 16, wherein the control circuit is operable to supply a speed command to control the motor assembly, and includes at least one of an EMI filter, a power supply, a driver circuit, a current limiter, a deadband generator, an under-voltage lockout circuit, and a PWM generator.

20. The motor assembly of claim 16, wherein the control circuit includes a low voltage circuit, a power line circuit, an isolator barrier to at least partially separate the power line circuit and the low voltage circuit, and external controls.

21. The motor assembly of claim 20, wherein the power line circuit is operable to relay power from a power line to the electric motor and includes at least one of an EMI filter, a driver circuit, and a first power supply.

22. The motor assembly of claim 20, wherein the low voltage circuit includes at least one of a current limiter, a deadband generator, a PWM generator, and under-voltage lockout circuit, a PWM to DC converter circuit, and a second power supply, and wherein the low voltage circuit interacts with the external controls to receive at least one of a DC voltage to operate the low voltage circuit and a speed command to operate the electric motor.