ELECTRIC POWER CONVERTING APPARATUS

• US 20120001597A1
• Filed: 12/21/2010
• Published: 01/05/2012
• Est. Priority Date: 07/02/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: GOKAN, Hiroshi, Suetake, Naruki, Tsujimoto, Katsuya
• Granted Patent: US 8,450,983 B2
• Time in Patent Office: Days
• US Class Current: 322/15
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 29/032 Preventing damage to the motor, e.g. setting individual current limits for different drive conditions
• CPC Class Codes: H02P 9/10 Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load
• CPC Class Codes: H02P 9/102 for limiting effects of transients

Abstract

A microcomputer that exercises driving control and power-generation control over a motor generator unit and a power-generation maintaining unit that, separately from the power-generation control exercised by the microcomputer, maintains a power-generation process performed by the motor generator unit are provided. While the microcomputer is operating normally, the power-generation maintaining unit allows the microcomputer to exercise the power-generation control. When an abnormality has occurred in the microcomputer, the power-generation maintaining unit maintains the power-generation process performed by the motor generator unit, in an autonomous manner independently of the microcomputer.

Claims

1. An electric power converting apparatus comprising:

a microcomputer that, based on a rotor current and stator phase voltages of a motor generator, exercises driving control and power-generation control over the motor generator; and

a power-generation maintaining unit that, separately from the power-generation control exercised by the microcomputer, maintains a power-generation process performed by the motor generator.

2. The electric power converting apparatus according to claim 1, wherein

the power-generation maintaining unit includes:

a power-generation maintaining circuit that monitors a power-generation state of the motor generator based on the stator phase voltages of the motor generator; and

a power-generation maintaining duty generating unit that, based on a result of the monitoring on the power-generation state performed by the power-generation maintaining circuit, controls a duty so that the power-generation process performed by the motor generator is maintained.

3. The electric power converting apparatus according to claim 2, wherein in a case where an overvoltage has been detected during the power-generation process performed by the motor generator, the power-generation maintaining duty generating unit controls the duty so that rotations of the motor generator are maintained.

4. The electric power converting apparatus according to claim 1, wherein

the power-generation maintaining unit includes a load dump detecting unit that, based on a stator bus voltage, monitors fluctuations in a load, independently of the microcomputer, and

the power-generation maintaining unit blocks the rotor current of the motor generator, based on a result of the monitoring on the fluctuations in the load performed by the load dump detecting unit.

5. The electric power converting apparatus according to claim 1, wherein

while the microcomputer is operating normally, the power-generation maintaining unit allows the microcomputer to exercise the power-generation control, whereas

in a case where an abnormality has occurred in the microcomputer, the power-generation maintaining unit maintains the power-generation process performed by the motor generator, in an autonomous manner independently of the microcomputer.

6. The electric power converting apparatus according to claim 1, wherein

the power-generation maintaining unit monitors itself, and

in a case where an abnormality has occurred in the power-generation maintaining unit, the power-generation maintaining unit allows the microcomputer to exercise the power-generation control.

7. The electric power converting apparatus according to claim 2, wherein

the power-generation maintaining circuit includes:

an overcurrent detecting unit that detects an overcurrent based on a result of monitoring on the rotor current;

a power-generation detecting unit that detects the power-generation process performed by the motor generator, based on results of monitoring on the rotor current, the stator bus voltage, and the stator phase voltages;

an undervoltage detecting unit that detects an undervoltage, based on a result of monitoring on the stator bus voltage; and

an overvoltage detecting unit that detects an overvoltage, based on a result of monitoring on the stator bus voltage, and

in a case where an undervoltage has been detected, the power-generation maintaining circuit raises the duty so that the power-generation process performed by the motor generator is maintained, whereas in a case where an overvoltage has been detected, the power-generation maintaining circuit lowers the duty so that rotations of the motor generator are maintained, and in a case where an overcurrent has been detected, the power-generation maintaining circuit turns off a switching element that drives a rotor.

8. The electric power converting apparatus according to claim 1, wherein

the power-generation maintaining unit includes:

a rotor rotation detecting unit that, based on a result of monitoring on a stator phase voltage, detects rotations of a rotor included in the motor generator; and

a rotation detection duty generating unit that, based on a result of the detection of the rotations of the rotor, maintains the rotations of the rotor.

9. The electric power converting apparatus according to claim 1, wherein

the power-generation maintaining unit includes:

a microcomputer monitoring unit that monitors operations of the microcomputer;

a rotor clock monitoring unit that monitors a clock used for an operation performed by the power-generation maintaining unit; and

a selector unit that switches signals so that, in a case where an abnormality has occurred in the microcomputer monitored by the microcomputer monitoring unit, a rotor included in the motor generator is controlled by the power-generation maintaining unit, whereas in a case where an abnormality has occurred in the clock monitored by the clock monitoring unit, the rotor included in the motor generator is controlled by the microcomputer.

10. The electric power converting apparatus according to claim 1, wherein the microcomputer exercises driving control over a stator, based on a result of detecting an angular position of a rotor.

11. The electric power converting apparatus according to claim 1, further comprising a stator controlling unit that exercises driving control over a stator, based on a result of detecting an angular position of a rotor.

12. The electric power converting apparatus according to claim 11, wherein the microcomputer performs communication with the power-generation maintaining unit and the stator controlling unit so as to detect an operation state of the motor generator.

13. The electric power converting apparatus according to claim 12, wherein in a case where normal communication has never been established with the microcomputer after a power-on reset is performed, if no abnormality is detected in the microcomputer, the power-generation maintaining unit switches a setting so that driving control or power-generation control is exercised over the motor generator by the microcomputer and the power-generation maintaining unit.

14. The electric power converting apparatus according to claim 12, wherein in a case where, when a communication failure has been detected in communication with the microcomputer, normal communication has been established with the microcomputer after a power-on reset is performed, the power-generation maintaining unit switches a setting so that the power-generation maintaining unit exercises power-generation control over the motor generator.

15. The electric power converting apparatus according to claim 11, wherein

the stator controlling unit includes:

a rotor angular position detecting unit that detects an angular position of the rotor;

a stator abnormality detecting unit that detects abnormalities in the stator based on a result of monitoring on stator phase voltages;

a stator control logic unit that exercises driving control over the stator, based on a result of the detection of the angular position of the rotor and a result of the detection of the abnormalities in the stator; and

a first serial communication interface that receives an operation instruction from the microcomputer and transmits information indicating an operation state of the stator to the microcomputer.

16. The electric power converting apparatus according to claim 15, wherein

the stator controlling unit includes a stator clock monitoring unit that monitors a clock used for an operation performed by the stator controlling unit, and

in a case where an abnormality has occurred in the clock monitored by the stator clock monitoring unit, the stator control logic unit stops the driving control exercised over the stator.

17. The electric power converting apparatus according to claim 1, wherein the power-generation maintaining unit includes a second serial communication interface that transmits information indicating an operation state of the rotor to the microcomputer.

18. The electric power converting apparatus according to claim 1, wherein when a setting has been switched so that driving control is exercised over the motor generator by the microcomputer, the power-generation maintaining unit allows the microcomputer to exercise the driving control, whereas when a setting has been switched so that power-generation control is exercised over the motor generator by the microcomputer, the power-generation maintaining unit either allows the microcomputer to exercise the power-generation control or allows the power-generation maintaining unit itself to maintain the power-generation process performed by the motor generator.

19. An electric power converting apparatus comprising:

a microcomputer that, based on a rotor current and stator phase voltages of a motor generator, exercises driving control and power-generation control over the motor generator;

a load dump detecting unit that, based on a stator bus voltage, monitors fluctuations in a load, independently of the microcomputer; and

a selector unit that, based on a result of the monitoring on the fluctuations in the load performed by the load dump detecting unit, blocks a rotor gate command signal that controls the rotor current.

20. An electric power converting apparatus comprising:

a microcomputer that, based on a rotor current and stator phase voltages of a motor generator, exercises driving control and power-generation control over the motor generator; and

a rotor control logic unit that, separately from the power-generation control exercised by the microcomputer, maintains rotations of the motor generator so that the rotations are detectable.