Robert Boschgmbh

Albrecht Schwarz

Peter Pfeffer

Daniel Raichle

Martin Trunk

Matthias Heil

Klaus Dressler

Axel Haas

An inverter for an electric machine as well as a method for operating an inverter for an electric machine. In this context, the inverter has at least one output stage unit for producing a connection between the electric machine and a power supply network, a control unit for controlling the at least one output stage unit, a supply unit independent of the power supply network for the power supply of the output stage unit(s), at least one emergency operation control assigned to the output stage unit(s) for controlling the output stage unit(s) in the fault case, as well as at least one emergency operation supply assigned to the output stage unit(s) for generating a power supply for the output stage unit(s) from the power supply network in the fault case.

Inverter for an electric machine and method for operating an inverter for an electric machine

The invention relates to a method for operating a power output stage (), in particular an electrical machine, which comprises a bridge circuit () with at least one half-bridge (), wherein the half-bridge () has two power semiconductor switches () which are connected in series and which are each supplied with an operating control voltage during normal operation in order to set a power voltage, and wherein the power voltage (u4, u5) of the respective power semiconductor switch () is detected for the purpose of short-circuit monitoring. In this case, provision is made, in order to check the functioning of the short-circuit monitoring means in a check mode for the power semiconductor switches (), for a test control voltage which is below the operating control voltage to be set at least temporarily at the same time.

Method and apparatus for operating a power output stage

An inverter system for operating an electric motor includes an input port for providing an electrical voltage, a bridge inverter circuit connected downstream from the input port for generating an electrical alternating voltage for the electric motor based on the electrical voltage. The bridge inverter circuit has at least one half-bridge branch including switching elements configured to be open for transferring the electric motor into a freewheeling state, and a decoupling switching element designed for decoupling the at least one half-bridge branch in the freewheeling state of the electric motor from the input port, in order to suppress a reaction of the freewheeling electric motor on the input port.

Inverter system for operating an electric motor

Measuring device for detecting a differential angle of rotation or

To provide for high efficiency of recuperation of energy stored in the rotating and electromagnetic system of a dynamo electric machine, upon dynamic braking thereof, in which the dynamo electric machine is connected in a chopper-controlled series circuit, a field diode (10) is connected across the field winding (11); a controlled switch (18), for example a transistor or a thyristor, is connected to the junction between the field winding (11) and the aramature (12, 13) and a return line (N) to a storage battery, the controlled switch being controlled to close by a control circuit (19) which opens a brake switch (16) connected between the battery and the dynamo electric machine series circuit under motor operating conditions, to provide for continued current flow through the field, which then is reversely connected by a field reversal switch (8, 9), with continued current flow being maintained by a free-wheeling diode (10) connected across the field. The chopper may be a thyristor (2) connected to a turn-off circuit, the turn-off capacitor (4) also furnishing initial field current through the controlled switch (18) or it may be a transistor (2') which is energized to conduction with a slight delay with respect to closing of the controlled switch (18).

Electric motor dynamic braking energy recuperating system

To reliably turn OFF a pulse-controlled thyristor in series with a battery supplied motor circuit, in case of malfunction of the control circuit, or even of the supervisory circuit itself, the voltage across the thyristor is sensed and, if an ON condition of the thyristor, as represented by sensed voltage, is determined while the pulse source does not provide an ON command, a disabling control signal is applied to the pulse source to provide an OFF command; in case of failure of the sensing element, an additional voltage is supplied, through a time delay circuit to the disabling input. Time delay circuits are interposed between the respective sensed signal and command signal and applied through a logic circuit to prevent spurious operation of the monitoring and safety circuit.

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Rutesheim, Germany

Albrecht Schwarz