MOTOR CONTROL SYSTEM

• US 20120319625A1
• Filed: 06/17/2011
• Published: 12/20/2012
• Est. Priority Date: 06/17/2011
• Status: Abandoned Application

• Current Assignee: Sanyi Heavy Equipment Company Limited (Sany Heavy Equipment International Holdings Co., Ltd.)
• Original Assignee: Sany Heavy Equipment, USA R&D Institute
• Inventors: Thomas, David G., Boggs, Hugh Jr., Twigger, Michael
• Application Number:
  US13/163,518
• Publication Number:
  US 20120319625A1
• Time in Patent Office: Days
• US Class Current: 318/51
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 5/74 controlling two or more ac dynamo-electric motors H02P5/46, H02P5/60 take precedence

Abstract

In one aspect of the present invention, a motor control system includes a rectifier module enclosed in a first flame-proof enclosure, and having a first input and one or more rectifier circuits configured to convert a first AC voltage at the first input to a DC voltage to be output to a DC bus, and one or more variable-frequency drive (VFD) modules, each VFD module being enclosed in a respective second flame-proof enclosure and having a second input coupled to the DC bus, where each VFD module includes one or more inverter circuits configured to convert the DC voltage on the DC bus to a second AC voltage to be output to one or more motors.

Claims

1. A motor control system, comprising:

(a) a rectifier module enclosed in a first flame-proof enclosure, wherein the rectifier module has a first input and includes one or more rectifier circuits configured to convert a first AC voltage at the first input to a DC voltage to be output to a DC bus; and

(b) one or more variable-frequency drive (VFD) modules, each VFD module being enclosed in a respective second flame-proof enclosure and having a second input coupled to the DC bus, wherein each VFD module includes one or more inverter circuits configured to convert the DC voltage on the DC bus to a second AC voltage to be output to one or more motors.

2. The motor control system of claim 1, wherein the first AC voltage is a three-phase AC voltage, and the one or more rectifier circuits comprise three rectifier circuits, each rectifier circuit coupled to a respective phase of the first AC voltage.

3. The motor control system of claim 2, wherein each rectifier circuit comprises a full-bridge rectifier circuit.

4. The motor control system of claim 3, wherein the full-bridge rectifier circuit comprises four insulated-gate bipolar transistors (IGBTs).

5. The motor control system of claim 1, wherein the second AC voltage is a three-phase AC voltage, and the one or more inverter circuits comprise three inverter circuits, each inverter circuit corresponding to a respective phase of the second AC voltage.

6. The motor control system of claim 5, wherein each inverter circuit comprises a full-bridge inverter circuit.

7. The motor control system of claim 6, wherein the full-bridge inverter circuit comprises four IGBTs.

8. The motor control system of claim 1, wherein the rectifier module further comprises a first inductor and a second inductor coupled to the one or more rectifier circuits in series and to a positive terminal and a negative terminal of the DC bus, respectively.

9. The motor control system of claim 8, wherein the rectifier module further comprises a filtering and energy storage circuit coupled between the positive terminal and the negative terminal of the DC bus.

10. The motor control system of claim 9, wherein the filtering and energy storage circuit comprises a diode and a resistor coupled to each other in parallel, and an energy-storage capacitor coupled to the diode and the resistor in parallel via an IGBT.

11. A motor control system for a mining equipment, comprising:

(a) a rectifier module enclosed in a first flame-proof enclosure, wherein the rectifier module has a first input and includes three rectifier circuits configured to convert a three-phase first AC voltage at the first input to a DC voltage to be output to a DC bus, each rectifier circuit coupled to a respective phase of the first AC voltage; and

(b) one or more VFD modules, each VFD module being enclosed in a respective second flame-proof enclosure and having a second input coupled to the DC bus, wherein each VFD module includes three inverter circuits configured to convert the DC voltage on the DC bus to a three-phase second AC voltage to be output to one or more motors, each inverter circuit corresponding to a respective phase of the second AC voltage.

12. The motor control system of claim 11, wherein each rectifier circuit comprises a full-bridge rectifier circuit.

13. The motor control system of claim 12, wherein the full-bridge rectifier circuit comprises four IGBTs.

14. The motor control system of claim 11, wherein each inverter circuit comprises a full-bridge inverter circuit.

15. The motor control system of claim 14, wherein the full-bridge inverter circuit comprises four IGBTs.

16. The motor control system of claim 11, wherein the rectifier module further comprises a first inductor and a second inductor coupled to the three rectifier circuits in series and to a positive terminal and a negative terminal of the DC bus, respectively.

17. The motor control system of claim 16, wherein the rectifier module further comprises a filtering and energy storage circuit coupled between the positive terminal and the negative terminal of the DC bus.

18. The motor control system of claim 17, wherein the filtering and energy storage circuit comprises a diode and a resistor coupled to each other in parallel, and an energy-storage capacitor coupled to the diode and the resistor in parallel via an IGBT.