Method for controlling an active bridge rectifier during load shedding, rectifier system, and computer program product

Patent metadata

Field	Value
Publication number	US-9985625-B2
Application number	US-201314425497-A
Country	US
Kind code	B2
Filing date	Jul 31, 2013
Priority date	Sep 3, 2012
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A method for controlling a bridge rectifier which includes active switching elements is provided, in which, during normal operation, at least one of the active switching elements is controlled using a voltage signal, the voltage of which is changed from a first voltage value to a second voltage value within at least one switching time. The at least one switching time is extended by a predefinable time period if load shedding at the bridge rectifier is determined. Also described is a corresponding rectifier system and a computer program product.

First claim

What is claimed is:

1. A method for controlling a bridge rectifier having active switching elements, the method comprising:
controlling, during normal operation, at least one of the active switching elements using a voltage signal, the voltage of which is changed, within at least one switching time, from a first voltage value at the start of the switching time to a second voltage value at the end of the switching time, wherein the lower of the first and second voltage values is below a threshold voltage of the switching element and the higher of the first and second voltage values is above the threshold voltage of the switching element; and
extending, when load shedding at the bridge rectifier is determined, the at least one switching time by a predefinable time period to decrease a slope of the voltage signal used to switch the at least one of the active switching elements.

2. The method of claim 1 , wherein in the at least one active switching element different resistance values are generatable between switching terminals which are switchable by the active switching element, the different resistance values generated by controlling the at least one of the active switching elements with different voltage values of the voltage signal between the first and the second voltage value.

3. The method of claim 2 , wherein controlling the at least one active switching element by continuously adjusting the voltage values between the first and the second voltage value results in a continuous change in the resistance between the switching terminals.

4. The method of claim 2 , wherein the at least one active switching element includes at least one transistor, and wherein a gate of the at least one transistor is acted on by the voltage signal.

5. The method of claim 4 , wherein the first voltage value is a voltage value which is below a threshold voltage of the at least one transistor, and wherein the second voltage value is a voltage value which is above the threshold voltage of the at least one transistor.

6. The method of claim 1 , wherein load shedding is determined based on an output signal which is output by the bridge rectifier during normal operation.

7. The method of claim 1 , wherein when load shedding is determined, a voltage signal which is present at a half bridge is diverted, at least temporarily, to a ground terminal via the at least one active switching element.

8. The method of claim 1 , wherein the time period by which the switching time is extended is determined based on a maximum allowed voltage rise and at least one inductance value in a network which the active bridge rectifier feeds.

9. A rectifier system, comprising:
a bridge rectifier having active switching elements;
a control device to control at least one of the active switching elements using a voltage signal, the voltage of which is changed, within at least one switching time, from a first voltage value at the start of the switching time to a second voltage value at the end of the switching time, wherein the lower of the first and second voltage values is below a threshold voltage of the switching element and the higher of the first and second voltage values is above the threshold voltage of the switching element;
a determining arrangement to determine load shedding at the bridge rectifier; and
an extending arrangement to extend, when loading shedding at the bridge rectifier is determined, the at least one switching time by a predefinable time period to decrease a slope of the voltage signal used to switch the at least one of the active switching elements.

10. A non-transitory machine-readable storage medium having program instructions, which when executed by a processor perform a method for controlling a bridge rectifier having active switching elements, the method comprising:
controlling, during normal operation, at least one of the active switching elements using a voltage signal, the voltage of which is changed, within at least one switching time, from a first voltage value at the start of the switching time to a second voltage value at the end of the switching time, wherein the lower of the first and second voltage values is below a threshold voltage of the switching element and the higher of the first and second voltage values is above the threshold voltage of the switching element; and
extending, when load shedding at the bridge rectifier is determined, the at least one switching time by a predefinable time period to decrease a slope of the voltage signal used to switch the at least one of the active switching elements.

11. The rectifier system of claim 9 , wherein the determining arrangement includes a comparator to compare a voltage at an output terminal of a generator including the bridge rectifier to a threshold voltage.

12. The rectifier system of claim 9 , wherein the extending arrangement includes a ramp controller to control to the slope of the voltage signal.

13. The method of claim 1 , wherein the at least one switching time is extended, and the slope of the voltage signal is decreased, relative to the at least one switching time and the slope of the voltage signal during normal operation.

14. The method of claim 1 , wherein the at least one active switching element is switched using the extended at least one switching time during a deactivation of a short circuit produced during load shedding by the at least one active switching element.

15. The method of claim 1 , wherein the at least one active switching element is switched using the extended at least one switching time during an activation of a short circuit produced during load shedding by the at least one active switching element.

16. The method of claim 1 , wherein only a single one of the at least one active switching elements is switched at any given time during load shedding.

Assignees

• Seg Automotive Germany Gmbh

Inventors

• Mehringer Paul
• Otte Christopher

Classifications

• H02M3/158

  including plural semiconductor devices as final control devices for a single load · CPC title

• H02H7/1252

  responsive to overvoltage in input or output, e.g. by load dump · CPC title

• H03K17/163 Primary

  Soft switching · CPC title

• H02H7/067

  on occurrence of a load dump (control on sudden change of load H02P9/10) · CPC title

• H02H7/10

  for converters; for rectifiers {(forming part of the control circuit of the converter, see the relevant group in H02M)} · CPC title