Electrical device with a pulsed power supply and method for testing the power supply of the electrical device

Patent metadata

Field	Value
Publication number	US-9817057-B2
Application number	US-201314060785-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Oct 23, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An electrical device having a clocked circuitry, and a method for testing the power supply unit of the electrical device. The electrical device comprises an electrical load, a clocked power supply unit, at least one pulse transformer and an evaluation device. The power supply unit comprises a power stack having at least one power semiconductor switch and is configured for generating a clocked voltage for the electrical load from an electric voltage based on an alternating on/off switching of the power semiconductor switch. The power stack exhibits at least one current path, through which an electric current flows during operation. The pulse transformer generates a signal assigned to the change in the charge and/or the direction of the electric current flowing through the current path. The evaluation device evaluates the signal coming from the pulse transformer and draws a conclusion regarding the operational reliability of the power semiconductor switch.

First claim

What is claimed is:

1. An electrical device, in particular an electrical machine, comprising
an electrical load,
a controller that generates a pulse width modulated signal having a pulse pattern,
a clocked power supply unit, comprising a power stack including a semiconductor switch, the power supply unit configured to generate an electrical supply voltage or an electric current for the electrical load from an electric voltage based on an alternating switching on and off of the semiconductor switch by the pulse width modulated signal, wherein the power stack exhibits at least one current path through which the electric current flows when the power supply unit is in operation,
a pulse transformer connected to a current path of the semiconductor switch, the pulse transformer configured to generate an output signal corresponding to a change of at least one of an absolute value or a direction of the electric current flowing through the current path of the semiconductor switch,
an evaluation circuit connected to the pulse transformer that couples the output signal to the controller,
wherein the controller is configured to determine the semiconductor switch is functioning properly if the output signal changes in accordance with the pulse pattern of the pulse width modulation signal.

2. The electrical device according to claim 1 , in which the power stack in the form of an inverter, and/or in which the semiconductor switch in the form of a power transistor, is designed, in particular, as a FET or a MOSFET, and/or in which the electrical load is implemented as an electrical inductive load.

3. The electrical device according to claim 2 , in which the inductive load is implemented as an electromechanical brake.

4. The electrical device according to claim 1 , in which the semiconductor switch is a component of a first current path of the at least one current path.

5. The electrical device according to claim 1 , the power stack of which is designed as an H-bridge, which exhibits a first current path, through which a first electric current flows when the power supply unit is in operation, a second current path, through which a second electric current flows when the power supply unit is in operation, a third current path, through which a third electric current flows when the power supply unit is in operation, and a fourth current path, through which a fourth electric current flows when the power supply unit is in operation, wherein the first current path and the fourth current path are connected by a first common node and the second current path and the third current path are connected by a second common node, between which the electrical load is connected, wherein the pulse transformer is assigned to one of the first current path, the second current path, the third current path, or the fourth current path, the pulse transformer being configured for generating the output signal corresponding to the change of the absolute value and/or the direction of the electric current flowing through the respective current path, and the controller is configured to determine a respective semiconductor switch is functioning properly if the respective output signal changes in accordance with the pulse pattern of the pulse width modulation signal.

6. The electrical device according to claim 5 , in which each of the current paths comprises one of the respective semiconductor switches.

7. The electrical device according to claim 5 , in which the first current path and the second current path each comprises at least one semiconductor switch and the third current path and the fourth current path comprise a diode.

8. The electrical device according to claim 5 , in which each of the current paths is assigned a respective pulse transformer, each of which is configured for generating a respective output signal corresponding to the change of the absolute value and/or the direction of the electric current flowing through the respective current path, and the controller is configured to determine the respective semiconductor switches are functioning properly if the respective output signals change in accordance with the pulse pattern of the pulse width modulation signal.

9. A method for testing a power supply unit of an electrical device having an electrical load, the power supply unit comprising a clocked power stack including a semiconductor switch and a current path through which an electric current flows when the power supply unit is in operation, the method comprising:
generating a pulse width modulated signal having a pulse pattern,
alternating switching on and off the semiconductor switch using the pulse width modulated signal to generate an electrical supply voltage or the electric current for the electrical load from an electric voltage,
generating, by a pulse transformer, an output signal corresponding to a change of at least one of an absolute value or a direction of the electric current through the current path of the semiconductor switch, and
determining the semiconductor switch is functioning properly if the output signal changes in accordance with the pulse pattern of the pulse width modulation signal.

10. An electrical device, in particular an electrical machine, comprising
an electrical load,
a controller that generates a pulse width modulated signal having a pulse pattern,
a clocked power supply unit, designed as an H-bridge, having at least two power semiconductor switches, the power supply unit exhibits a first current path, through which a first electric current flows when the power supply unit is in operation, a second current path, through which a second electric current flows when the power supply unit is in operation, a third current path, through which a third electric current flows when the power supply unit is in operation, and a fourth current path, through which a fourth electric current flows when the power supply unit is in operation, wherein the first current path and the fourth current path are connected by a first common node and the second current path and the third current path are connected by a second common node, between which the electrical load is connected, and in which a first semiconductor switch is a component of the first current path, and a second semiconductor switch is a component of the second current path,
a separate pulse transformer assigned to each of the current paths, each pulse transformer configured for generating an output signal corresponding to a change of an absolute value and/or a direction of the electric current flowing through the respective current path; and
an evaluation circuit connected to each pulse transformer that couples the corresponding output signal to the controller,
wherein the controller is configured to determine the semiconductor switches are functioning properly if the output signals change in accordance with the pulse pattern of the pulse width modulation signal.

Assignees

• Kuka Lab Gmbh
• Kuka Roboter Gmbh

Inventors

• Langhans Michael
• Zehetbauer Sebastian

Classifications

• H02M3/155 Primary

  using semiconductor devices only · CPC title

• G01R31/42 Primary

  AC power supplies · CPC title

• G01R31/2621 Primary

  for testing field effect transistors, i.e. FET's · CPC title

• G01R31/40

  Testing power supplies (testing photovoltaic devices H02S50/10) · CPC title

• H02M3/145

  using devices of a triode or transistor type requiring continuous application of a control signal · CPC title