Safe shutdown of an inverter
AssigneeZF Friedrichshafen AG
InventorRobert Maier
Life of this patent
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Abstract
An output stage for an inverter for driving an electrical machine includes a half-bridge containing a current valve embodied as a JFET. The current valve is configured to be controlled by a driver. The output stage comprises a cutout circuit for opening the current valve when the driver has no supply voltage, wherein the cutout circuit includes a capacitor and a diode, which are connected in series between a gate terminal and a source terminal of the current valve, an additional JFET for bypassing the diode, and a drive, which keeps a voltage between a gate terminal and a source terminal of the additional JFET small enough to close the additional JFET as long as a supply voltage of the driver is large enough.
Claims11
An output stage for an inverter for driving an electrical machine, the output stage comprising:
- a half-bridge containing a current valve embodied as a JFET, wherein the current valve is configured to be controlled by a driver;
- a cutout circuit configured to open the current valve when the driver has no supply voltage, wherein the cutout circuit comprises:
- a capacitor and a diode connected in series between a gate terminal and a source terminal of the current valve;
- an additional JFET configured to bypass the diode;
- and
- a drive configured to keep a voltage between a gate terminal and a source terminal of the additional JFET low enough to close the additional JFET as long as a supply voltage of the driver is above a predetermined threshold value.
Dependencies are inferred from the claim text.