Safety circuit arrangement for an electrical drive unit

Abstract

A safety circuit arrangement is provided for an electrical drive unit, wherein the electrical drive unit includes a traction battery, an intermediate circuit capacitance connected in parallel to the traction battery, and an electric machine which can be supplied with electrical power by the traction battery. The electric machine has a plurality of phases which can be connected to the traction battery via a controllable inverter having a plurality of switch elements. The safety circuit arrangement includes: a discharge circuit which is designed to take a predeterminable discharge current from the intermediate circuit capacitance in the activated operational state of the discharge circuit, a short-circuit control circuit which is designed to short-circuit at least some of the phases of the electric machine by controlling some of the switch elements in the activated operational state of the short-circuit control circuit, a supply voltage circuit which is designed to provide a supply voltage on the basis of input voltage delivered to the supply voltage circuit, an intermediate circuit voltage applied to the intermediate circuit capacitor being delivered as input voltage, and an activating element which is designed to close an activation path when a switch-on condition is present in order to activate the discharge circuit and the short-circuit control circuit by providing the supply voltage.