| 摘要 |
An electronically commutated direct current machine, comprising a rotor and a stator, has a stator winding arrangement which can be supplied with power fr om a direct current source (73, 74) by a full bridge circuit (78). A commutatio n arrangement (49, 50, 52, 54) for commutating the semiconductor switches (1) (80 to 85) is provided and is configured for switching on one of the semiconductor switches in dependence on at least the position of the rotor (110) at a first bridge branch, respectively and for alternately switching o n and off a semiconductor switch that is allocated to the switched on semiconductor switch of the first bridge branch, at a second bridge branch, controlled by a clocking signal (PWM2). The invention also provides an arrangement that is configured for generating a reference clocking signal (PWM1), which controls the duty ratio for the alternate switching on and off of the semiconductor switch that is allocated to the first bridge branch by its intensity. A current limiting arrangement (131, 161) which can be controlled by a current desired value signal (PWM I+; PWM I-) is also provided. When a current defined by the current desired value signal is reached in the direct current machine, said arrangement modifies the referen ce clocking signal in such a way that the current in the direct current machine is not greater than a limit current that is set by the current desired value signal. |
