Apparatus and method for detecting an electric current flow through a diode, and electric drive system
AssigneeRobert Bosch GmbH
InventorsDaniel Schweiker, Ekard Grossmann
Life of this patent
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Abstract
Detection of an electric current through a diode arranged parallel to a semiconductor switching element. For this purpose, an output signal of a circuit arrangement for saturation monitoring (desat circuit) is used. The output signal is evaluated at periods in which the semiconductor switching element is opened.
Claims12
An apparatus for detecting an electric current through a diode (D), wherein the diode (D) is arranged parallel to a semiconductor switching element (S1-S6) of a half-bridge, and wherein the apparatus comprises:
- a circuit arrangement (21) for saturation monitoring of the semiconductor switching element (S1-S6), configured to detect an electrical voltage across the semiconductor switching element (S1-S6) and the diode (D) arranged parallel thereto, and to provide an output signal corresponding to the detected voltage, wherein the circuit arrangement (21) is configured as a DESAT circuit that simulates the electrical voltage across the semiconductor switching element (S1-S6), the electric voltage being limited to an amount of a supply voltage;
- and
- a detection device (22) configured to detect an electric current through the diode (D) using the output signal from the circuit arrangement (21) for saturation monitoring when the semiconductor switching element (S1-S6) of the half-bridge arranged parallel to the diode is opened.
A method for detecting an electric current through a diode (D), wherein the diode (D) is arranged parallel to a semiconductor switching element (S1-S6) in a half-bridge, the method comprising:
- detecting (100) an electrical voltage across the semiconductor switching element (S1-S6) and the diode (D) arranged parallel thereto by means of a circuit arrangement (21) for saturation monitoring of the semiconductor switching element (S1-S6) and providing an output signal corresponding to the detected voltage, wherein the detected voltage across the semiconductor switch element (S1-S6) is simulated by a circuit arrangement (21) configured as a DESAT circuit, the electric voltage being limited to an amount of a supply voltage;
- and
- detecting (200) an electric current through the diode (D) using the provided output signal when the semiconductor switching element (S1-S6) of the half-bridge arranged parallel to the diode (D) is opened.
Dependencies are inferred from the claim text.