| 摘要 |
Method and apparatus for controlling a frequency converter, which frequency converter comprises a rectifier (REC) connected to the input voltage, a three-phase inverter (INU) provided with controllable solid-state switches, an intermediate voltage circuit between these, and also a control system, which is supplied with two auxiliary voltage sources, and
which frequency converter controls the operation of an electric motor (M) connected to it, and
which frequency converter comprises two auxiliary voltage sources (PS1, PS2), operating in different voltage ranges and to be connected to the intermediate voltage circuit, to each of which auxiliary voltage sources an own control unit (CU1, CU2) is connected, both of which control units are able to form a three-phase control pulse pattern controlling the inverter (INU),
which first auxiliary voltage source (PS1) is controlled to operate when the intermediate circuit voltage rises to a first level, and it supplies operating voltage at least to the first control unit (CU1) and to the gate drivers controlling the power semiconductors of the inverter,
which second auxiliary voltage source (PS2) is controlled to operate when the intermediate circuit voltage rises to a second level, and it supplies operating voltage at least to the second control unit (CU2) and to the gate drivers controlling the power semiconductors of the inverter, and
wherein when the second control unit energizes to operate, the using of the control signals formed by the first control unit for controlling the power semiconductors of the inverter is prevented. |
