Communication protocol

• US 9,407,253 B2
• Filed: 03/08/2013
• Issued: 08/02/2016
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: Maschinenfabrik Reinhausen GmbH (Richard Scheubeck Beteiligungs-Gmbh & Co. KG)
• Original Assignee: Maschinenfabrik Reinhausen GmbH (Richard Scheubeck Beteiligungs-Gmbh & Co. KG)
• Inventors: Cronin, Ivan
• Primary Examiner(s): Hernandez, William
• Application Number:
  US14/391,171
• Publication Number:
  US 20150097598A1
• Time in Patent Office: 1,243 Days
• Field of Search: 326/82, 326/83, 326/87, 326/89, 326/91, 327108-112
• US Class Current: 1/1
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H03K 17/18 Modifications for indicating state of switch

Abstract

The application generally relates to apparatus for driving high voltage power switching devices such as IGBTs. An aspect provides a method of adding a sensing capability to a device driver for driving at least one high voltage power switching device of a power switching apparatus having device side circuitry comprising said at least one device and said driver and having control side circuitry comprising a driver controller, the device driver arranged to be coupled to a said driver controller by a communications link, the device driver arranged to drive said at least one device on or off in response to a switching signal received on said communications link from the driver controller, the device driver further arranged to transmit an acknowledge signal to said driver controller in response to said received switching signal, said acknowledge signal detectable at said driver controller as a valid said acknowledge signal, the method comprising: providing a sense circuit to output an indication of a condition of said device side circuitry; providing a modulation circuit to modulate a said acknowledge signal dependent on said condition indication prior to said transmission such that said modulated acknowledge signal is said acknowledge signal to be transmitted by said device driver to said driver controller in response to said received switching signal and detectable at said driver controller as a valid said acknowledge signal.

Claims

1. A method of adding a sensing capability to a device driver for driving a high-voltage power-switching device of a power switching apparatus having device-side circuitry comprising the power-switching device and the device driver and having control-side circuitry comprising a driver controller, the device driver arranged to be coupled to the driver controller by a communications link, the device driver arranged to drive the power-switching device on or off in response to a switching signal received on said communications link from the driver controller, the device driver further arranged to transmit an acknowledge signal to the driver controller in response to the, said acknowledge signal being detectable at the driver controller as valid, the method comprising:

outputting with a sense circuit an indication of a condition of said device-side circuitry; and

modulating with a modulation circuit the acknowledge signal dependent on said condition indication prior to said transmission and to transmit the modulated acknowledge signal by said device driver to the driver controller in response to the received switching signal and detectable at the driver controller as valid.

2. The method of claim 1, wherein the acknowledge signal detectable at the driver controller as valid has a duration compliant with predefined minimum and/or maximum values.

3. The method of claim 1, wherein said condition represents a status of the device-side circuitry or a measured value of a parameter of the device-side circuitry, and

said modulation comprises modulating the acknowledge signal to encode said status or measured value into the acknowledge signal, the acknowledge signal being generated in response to a respective said switching signal.

4. The method of claim 3, wherein said status represents whether a parameter of the device-side circuitry is below a threshold to indicate whether the power-switching device is operating within a safe operating limit of said power-switching device.

5. The method of claim 3, wherein said parameter comprises:

a temperature, voltage or current of said power-switching device;

or

a timing of a peak voltage or peak current of the power-switching device.

6. The method of claim 3, wherein said parameter comprises:

a power-switching device gate or gate-emitter voltage;

a power supply voltage of said device-side circuitry;

a power-switching device collector-emitter saturation voltage;

a power-switching device collector or collector-emitter voltage;

an ambient temperature of said device-side circuitry;

or

a power-switching device switching time.

7. The method of claim 1, wherein the modulation modulates each of a plurality of said acknowledge signals to represent a bit of a multi-bit value representing the condition, to thereby transmit said multi-bit value from the device driver.

8. The method of claim 1, wherein said modulation modulates the acknowledge signal to represent a plurality of bits of a multi-bit value representing the condition.

9. The method of claim 1, wherein said acknowledge signal comprises a pulse and said modulation adjusts a duration of said pulse signal dependent on said condition such that the adjusted duration is between a minimum duration and a maximum duration of a valid said acknowledge pulse.

10. The method of claim 9, wherein said minimum duration of said valid acknowledge pulse is about 0.6 μ

s and said maximum duration of said valid acknowledge pulse is about 1.8 μ

s.

11. The method of claim 9, wherein said modulation adjusts said duration to be about 0.8 μ

s to indicate a data bit and to be about 1.6 μ

s to indicate another data bit.

12. The method of claim 1, wherein said modulation comprises frequency modulation, amplitude modulation, and/or pulse width modulation, and said modulation is for encoding of multi-level digital data.

13. A method of adding a monitoring capability to a driver controller for controlling a device driver to drive a high-voltage power-switching device of a power switching apparatus, the apparatus having device-side circuitry comprising the power-switching device and the device driver and having control-side circuitry comprising the driver controller, the driver controller arranged to be coupled to the device driver by a communications link, the driver controller arranged to transmit a switching signal on the communications link to control the device driver to drive the power-switching device on or off, the driver controller further arranged to receive an acknowledge signal from said communications link and to detect a valid said received acknowledge signal as a response to said switching signal, the method comprising:

providing a demodulation circuit to demodulate the detected valid acknowledge signal to thereby output a condition of said device-side circuitry, said condition encoded in said acknowledge signal.

14. A device driver for driving a high-voltage power-switching device of a power switching apparatus, the apparatus having device-side circuitry comprising the power-switching device and the device driver and having control-side circuitry comprising a driver controller, the device driver arranged to be coupled to the driver controller by a communications link, the device driver arranged to drive the power-switching device on or off in response to a switching signal received on said communications link from the driver controller, the device driver further arranged to transmit an acknowledge signal to the driver controller in response to the received switching signal, said acknowledge signal detectable at the driver controller as valid, the device driver comprising:

an input arranged to receive a condition indication of said device-side circuitry; and

a modulator configured to modulate the acknowledge signal dependent on said received condition indication, wherein the device driver is configured to transmit said modulated acknowledge signal as said acknowledge signal detectable at the driver controller as valid.

15. A driver controller for controlling a device driver to drive a high-voltage power-switching device of a power switching apparatus, the apparatus having device-side circuitry comprising the power-switching device and the device driver and having control-side circuitry comprising the driver controller, the driver controller arranged to be coupled by a communications link to the device driver, the driver controller arranged to transmit on said communications link a switching signal to control said device driver to drive the power-switching device on or off, the driver controller arranged to receive an acknowledge signal on said communications link from said device driver and to detect a valid said received acknowledge signal, the driver controller comprising:

a demodulator configured to demodulate said received acknowledge signal to thereby determine data encoded in said acknowledge signal; and

an output configured to provide an indication of a condition of the device-side circuitry on the basis of said determined data.

16. The power switching apparatus of claim 15, wherein the apparatus comprises an inverter.

17. The power switching apparatus of claim 15, wherein said power-switching device comprises an IGBT or an FET such as a JFET or a MOSFET, and wherein said device driver is arranged to drive a gate of said IGBT or FET.

18. A method of communicating configuration/measurement data in a power semiconductor switching device control system, said power semiconductor switching device control system comprising a coordinating control system and a plurality of switching device controllers, each coupled to said coordinating control system and each configured to control one or more respective power semiconductor switching devices;

the method comprising;

sending control data comprising data for controlling switching to one or more of said switching device controllers;

receiving an acknowledgment signal at said coordinating control system, wherein said acknowledgment signal comprises a pulse having leading and trailing edges, and wherein a timing interval between said leading and trailing edges has a permitted variation within which said acknowledgment signal is a valid signal;

the method further comprising;

encoding said configuration/measurement data into said acknowledgment signal within a timing window defined by said permitted variation such that said acknowledgment signal is an encoded acknowledgment signal;

sending said encoded acknowledgment signal from the switching device controller to said coordinating control system; and

decoding said configuration/measurement data from said encoded acknowledgment signal at said coordinating control system;

wherein said configuration/measurement data comprises data relating to a configuration of, or measurement on, said switching device controller or said power semiconductor switching device respectively.

19. A method as claimed in claim 18 wherein said encoding comprises changing said timing interval to encode said configuration/measurement data within a permitted variation of a duration of said pulse for said acknowledgment signal to be valid.

20. A method of retrofitting a configuration/measurement capability to an existing power semiconductor switching device control system, said power semiconductor switching device control system comprising a coordinating control system and a plurality of switching device controllers, each coupled to said coordinating control system and each configured to control one or more respective power semiconductor switching devices;

the method comprising;

using the method of claim 18 to encode said configuration/measurement data within a permitted variation of a duration of said pulse for said acknowledgment signal to be valid within said existing power semiconductor switching device control system.