Device for switching a semiconductor-based switch and sensor for detecting a current change velocity at a semiconductor-based switch

Patent metadata

Field	Value
Publication number	US-2017040802-A1
Application number	US-201615331694-A
Country	US
Kind code	A1
Filing date	Oct 21, 2016
Priority date	Apr 24, 2014
Publication date	Feb 9, 2017
Grant date	—

Abstract

A device for switching a semiconductor-based switch includes a terminal that is configured to be connected to a control terminal of the semiconductor-based switch. A controllable activation voltage source is configured to provide a time-varying activation voltage potential. A controllable resistive circuit includes at least two ohmic resistances connected in parallel that are controllable such that at least three resistance values of the parallel connection result. A control device is configured to control the controllable activation voltage source and the controllable resistive circuit independently of one another. The controllable activation voltage source and the controllable resistive circuit are connected to a series connection connected to the terminal. The control device is configured to control the controllable activation voltage source and the controllable resistive circuit in a time-varying manner to obtain time-varying resistance values of the controllable resistive circuit and the time-varying activation voltage potential of the controllable activation voltage source.

First claim

1 . Device for switching a semiconductor-based switch, comprising:
a terminal configured to be connected to a control terminal of the semiconductor-based switch; a controllable activation voltage source configured to provide a time-varying activation voltage potential; a controllable resistive circuit comprising at least two ohmic resistances connected in parallel, which are controllable such that at least three resistance values of the parallel connection result; and a control device configured to control the controllable activation voltage source and the controllable resistive circuit independently of one another; wherein the controllable activation voltage source and the controllable resistive circuit are connected in a series connection that is connected to the terminal; and wherein the control device is configured to control the controllable activation voltage source and the controllable resistive circuit in a time-varying manner in order to acquire time-varying resistance values of the controllable resistive circuit and the time-varying activation voltage potential of the controllable activation voltage source, such that a time-varying voltage potential based on the time-varying resistance values and the time-varying activation voltage potential can be applied to the control terminal.

2 . Device according to claim 1 , wherein the controllable activation voltage source comprises a first circuit path connected to a source potential and comprising a first controllable switch, and a second circuit path connected to an adjustable voltage potential and comprising a second controllable switch, wherein the first circuit path and the second circuit path are connected to one another at a circuit node at an end facing away from the source potential and the adjustable voltage potential, wherein the circuit node is connected to the controllable resistive circuit, such that based on a position of the first and second controllable switches the adjustable voltage potential or the source potential can be applied to the controllable resistive circuit.

3 . Device according to claim 2 , wherein the controllable activation voltage source is a digitally adjustable voltage regulator, wherein the source voltage is an operating voltage of the device and wherein the voltage regulator is configured to control the adjustable voltage potential gradually between a minimum value and the source potential.

4 . Device according to claim 3 , wherein the minimum value is a threshold voltage of the semiconductor-based switch or a control potential of the semiconductor-based switch, which enables an active state of the semiconductor-based switch.

5 . Device according to claim 2 , wherein the control device is configured to place the first controllable switch and the second controllable switch simultaneously in an open state, such that current flow from the controllable activation voltage source to the terminal is prevented.

6 . Device according to claim 2 , wherein the control device is configured to convert, during an activation phase, the semiconductor-based switch from the first switching state to the second switching state and to connect, during the activation phase, the controllable resistive circuit to the adjustable voltage potential and to connect, during a time interval preceding the activation phase, the source potential to the controllable resistive circuit.

7 . Device according to claim 1 , wherein the control device is configured to acquire, in intervals, in a preceding control time interval, a comparative result based on a comparison of a current change velocity of a power current flowing through the semiconductor-based switch with a comparative value, and to adjust the controllable activation voltage source based on the comparative result for a control time interval following the preceding control time interval, such that the time-varying voltage potential is increased when the comparative result is less than a predefined lower limit and that the time-varying voltage potential is reduced when the comparative result is greater than a predefined upper limit.

8 . Device according to claim 1 , wherein the control device comprises a digital control that is configured to control the controllable resistive circuit and the controllable activation voltage source for a current control time interval based on a comparison of set values of a current change velocity of a power current flowing through the semiconductor-based switch and a control current flowing to or away from the control terminal of the semiconductor-based switch with measurement values of the current change velocity of the power current, wherein the set values are valid for a current control time interval, wherein the set values are derived from actual values of a preceding control time interval and wherein the digital control is configured to determine, based on the comparison, an amended time period of a time interval for the current control time interval.

9 . Device according to claim 1 , further comprising a controllable deactivation voltage source connected to the terminal and configured to provide, at least temporarily, a switching potential, wherein the switching potential is galvanically coupled to a supply potential of the control device and has a lower potential value than a threshold voltage of the semiconductor-based switch and wherein the control device is configured to control the controllable deactivation voltage source such that, based on the provided switching potential, charge carriers stored in a control capacitance of the semiconductor-based switch flow out of the control capacitance and contribute to an operation of the control device based on the galvanic coupling.

10 . Device according to claim 1 , further comprising a sensor for detecting a current change velocity of a power current flowing through the semiconductor-based switch, the sensor comprising:
an insulating foil configured to be connected to the first or second terminal of the semiconductor-based switch; and an inductance arranged on the insulating foil on a side of the same that is arranged opposite to a side facing the semiconductor-based switch during a measurement operation of the sensor in order to detect a magnetic field generated by the power current and to provide a measurement voltage based on the detected magnetic field; wherein the inductance is spaced apart from the semiconductor-based switch during the measurement operation at least by the insulating foil, such that contactless measurement of the current change velocity by the sensor is enabled; wherein the insulating foil further comprises a mounting portion; and wherein the first or second terminal of the semiconductor-based switch is connected to the mounting portion of the insulating foil.

11 . Device according to claim 1 , further comprising an inverse feedback branch that is configured to connect, based on a current rise velocity of a power current flowing through the semi-conductor based switch, the terminal to a static OFF-voltage, such that current flowing from the terminal to the control terminal of the semi-conductor based switch is reduced, wherein the inverse feedback branch is configured to be effective when the current rise velocity reaches or exceeds a predefined threshold.

12 . Device according to claim 10 , wherein the inverse feedback branch comprises a transistor and wherein the current rise velocity is represented as a measurement signal of a sensor connected to the transistor at a control input of the transistor.

13 . Device according to claim 1 , further comprising:
a controllable deactivation voltage source connected to the terminal and configured

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• Hopperdietzel René

Classifications

• H10W42/80

  protecting against overcurrent or overload, e.g. fuses or shunts (integrated devices comprising arrangements for electrical protection H10D89/60) · CPC title

• G01R19/14

  Indicating direction of current; Indicating polarity of voltage · CPC title

• H02J4/00 Primary

  Circuit arrangements for mains or distribution networks not specified as AC or DC; Circuit arrangements for mains or distribution networks combining AC and DC sections or sub-networks (arrangements using intermediate DC-AC-DC conversion H02J1/002; arrangements using high-voltage DC [HVDC] links H02J3/36) · CPC title

• H03K17/0828 Primary

  in composite switches · CPC title

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title