NOVELTY - The circuit has a measuring circuit (5) that measures a value of DC voltage (Uc) of a DC voltage intermediate circuit and outputs a voltage signal. A current sensor (4) measures a current flowing between a DC intermediate circuit air supplying inverter (7) and a DC intermediate circuit energy storage device. A control circuit (6) activates and deactivates the operation of a low pass filter (6a) in response to a current value (Is), and outputs a drive signal for the inverter based on the filtered or unfiltered voltage signal in response to an activation state of the filter.    USE - Protection circuit for direct current (DC) voltage intermediate circuit for electrical propulsion system such as wind-power plants, photovoltaic systems or force heat coupling plants, energy store plants, reservoir power plants, accumulator battery power plants, flywheel storage, and pump storages, for use in electrical driven vehicle such as electric vehicle or hybrid vehicle, ships, motorboats, etc.    ADVANTAGE - The voltage which is increased over the critical maximum value over outside is prevented. The increase of the voltage remains limited according to the point of time due to residual currents on the critical maximum value is ensured. The robustness is ensured opposite voltage peaks by a clock operation in the generator mode of operation electrical propulsion system and a quick response time in the event of an error is decreased, without damaging the electric components. The direct voltage intermediate circuit is protected without expensive and costly capacitors with high buffer capacity. The installation space and system weight are saved in the electrical propulsion system.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) an electrical propulsion system; and    (2) a method for protecting a direct voltage intermediate circuit.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the electrical propulsion system.    Current sensor (4)    Measuring circuit (5)    Control circuit (6)    Low pass filter (6a)    DC intermediate circuit air supplying inverter (7)    Current value (Is)    DC voltage (Uc)