Bayerische Motoren Werke Aktiengesellschaft

Georg Goetz

Michael Bauer

Markus Kaindl

Juergen Gebert

Hans Glonner

Marcel Fenkart

Florian Oesterreicher

Michael Preis

Andreas Buchner

Florian Pfattrisch

Sylvester Burckhardt

Karl Brinz

Siegfried Friedmann

Jurgen Krause

A method of operating an electric system of a motor vehicle, consisting of a fuel cell system, an accumulator and an electric driving motor is provided. Without implementing an electric voltage conversion and therefore without an electric voltage converter, as a function of the level of the electric voltage made available by the fuel cell system and by the accumulator and the electric power demanded by the electric motor, a first switching element in the connection between the fuel cell system and a node point electrically connected with the accumulator and the electric motor, as well as a second switching element in the connection between the accumulator and this node point are opened or closed as needed. This is done such that the power requirement of the electric motor is met primarily from the fuel cell system, and in an auxiliary fashion, additionally from the accumulator. If the electric power offered by the fuel cell system exceeds the electric power demanded by the electric motor, the excess power will be fed to the accumulator for as long as its permissible charging current is not exceeded and the accumulator still has a defined residual storage capacity.

Operating method for an electric energy system of a motor vehicle comprising a fuel cell system, an accumulator and an electric motor

A motor vehicle (KFZ) including an electric power source (EQ) for providing DC current, a converter (U) for converting the DC current into three-phase AC current of identical phase angle or polyphase current as a function of the vehicle operating state, and an electric machine (EM), to which the current provided by the converter is fed, is provided.

Motor Vehicle

A motor vehicle is provided with a capacitor device for storing electric energy. The capacitor device is specifically discharged by a short-circuiting switch, which is arranged in parallel to the terminal posts of the capacitor device, without any intermediary activity of a separate discharge resistor.

Motor vehicle with a capacitor device for storing electric energy

In a power control system for motor vehicles with a plurality of power-converting elements as well as sensors for determining the efficiency of the individual elements, a processor determines the overall system efficiency from the efficiencies of the individual components, and calculates and adjusts a value for a parameter that influences the efficiency of at least one component to achieve an optimum total efficiency. Surplus power is used to charge an energy storage device. Preferably the parameters that influence the efficiency, whose values are adjusted to achieve an optimum total efficiency, are the power, or a parameter that is proportional to the power, that is to be delivered by a power-generating component, and/or the rpm or a parameter that is proportional to the rpm of a component.

Power control system for motor vehicles with a plurality of

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Steinkirchen, Germany

Georg Goetz