Robert Boschgmbh

Robert Bosch Gmbh

Michael Heeb

Michele Hirsch

Torsten Heidrich

Markus Kretschmer

Tobias Werner

Christian Djonga

Stefan Gaab

The invention relates to a method for determining the temperature of a power electronics unit () which has at least one commutator circuit () and a load () which is powered/can be powered by the commutator circuit (). The commutator circuit () comprises a first semiconductor switch device (), which has a first semiconductor switch () and optionally a first diode (), and a second diode (), wherein the second diode () and the load () are connected in parallel to the first semiconductor switch (). The curve of an electric current flowing through the second diode () is monitored at least when a reverse current is produced in the second diode () after the semiconductor switch () has been switched so as to become conductive. On the basis of the current curve, the temperature of a barrier layer of the second diode () is determined. A difference between a current value of a circuit current flowing through the commutator circuit () and an extremal current value {Imax) produced by the reverse current is ascertained on the basis of the current curve, and the temperature of the barrier layer of the second diode () is determined on the basis of the difference.

Method for determining the temperature of a power electronics unit, device, and power electronics unit

The invention relates to a method for operating an electrical machine () controlled by an inverter (), wherein the inverter () comprises half-bridge branches (-U,-V,-W) having power components in the form of controllable power switching elements () and power diodes () respectively connected in parallel therewith, wherein each of the half-bridge branches (-U;-V;-W) is arranged on a separate semiconductor module (-U;-V;-W), which are arranged jointly on a baseplate (), wherein the phase currents (1_U, 1_V, 1_W) flowing through the half-bridge branches (-U,-V,-W), the voltages present at the power components and temperatures (t_Sens_U, t_Sens_V, t_Sens_W) on the semiconductor modules (-U,-V,-W) are determined, from the current (1_U; 1_V; 1_W) respectively flowing at a power component and from the voltage respectively present a power loss (P) is calculated for each of the power components, from the power losses (P) a relevant temperature swing (&#x394;t; &#x394;t_Sens) is determined for each of the power components and for temperature sensors (-U,-V,-W) serving to determine the temperatures on the semiconductor modules, a temperature (TempCooler) of the baseplate () is determined from the determined temperatures (t_Sens_U, t_Sens_V, t_Sens_W) on the semiconductor modules (--V,-W) and the determined temperature swings (&#x394;t_Sens) at the temperature sensors (-U,-V,-W), and a torque or a power of the electrical machine () is determined in a manner dependent on the determined temperature swings (&#x394;t) and the determined temperature (TempCooler) of the baseplate ().

Control device and method for operating an electrical machine driven by an inverter

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Stuttgart, Germany

Michael Heeb