Robert Boschgmbh

Thomas Heese

Gerhard Knecht

Markus Heidrich

Harald Witzig

A method for driving at least one inductive load using pulse width modulated control signals, via a PWM control unit, the control pulses of the PWM control signals connecting the load to and disconnecting it from a d.c. supply voltage via a semiconductor output stage. To prevent the formation of an a.c. voltage occurring on the d.c. supply voltage in the case of pulse-wise loading of the same by the PWM control signal, the PWM control unit is assignable a supplementary device including a storage capacitor and/or storage inductor having a semiconductor switch, and the semiconductor switch is controllable by the PWM control unit switch on one charging current circuit powered by the d.c. supply voltage for the storage capacitor and/or the storage inductor.

Method for driving at least one inductive load using pulse width modulated control signals

The method of controlling a converter of a switched reluctance machine includes clocking a power switch with a frequency that depends on the width of the hysteresis band. The hysteresis width is varied according to reluctance machine speed, especially so that a difference between maximum and minimum values with which the current is switched on and off either increases with decreasing speed, decreases with increasing load, or both. The changing of the hysteresis width occurs so that a difference between maximum and minimum threshold values either increases with decreasing speed, decreases with increasing load, or both. The width of the hysteresis band preferably varies linearly with speed, load and/or current, especially so that the width of the hysteresis band varies linearly so that the clocking frequency is maintained substantially constant. Also targeted changes in the width of the hysteresis band are made to move the clocking frequency from near noise-critical resonance frequencies.

Method of controlling a frequency converter of a reluctance machine

A reluctance motor electric machine including a number of stator pole teeth and a number of rotor pole teeth selected so that with a minimal reluctance, due to the rotational alignment of the rotor in relation to the stator, three air gaps that can be flowed through are produced between three pairs of stator pole teeth and rotor pole teeth. This results in the fact that now three regions of the yoke body are elastically pulled in the direction of the rotor rotational axis and consequently, the elastically deformed zones of the yoke body only extend over essentially and therefore act in a more rigid fashion. This results in the advantage that with the same excitation frequency, the deformations take place with small amplitudes and therefore with less generation of noise.

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Buehl, Germany

Thomas Heese