| 摘要 |
An elevator system is powered by a multiphased motor to which power is supplied from an inverter, which is powered by a battery. The collector-emitter voltage across the output transistors in the inverter is sensed as the transistors are turned on, and if the voltage does not drop to the saturation voltage within a certain time, the drive to the inverter is discontinued. If at any time while the transistors are in saturation saturation voltage rises, the drive is turned off. To start the drive, the transistors are permitted to turn on for a short interval of time. If, following that interval of time, the saturation voltage is not correct, the drive is turned off. The inverter has separate sections for driving each winding of the motor, and each of these sections has a separate power supply and fault detection circuit, which operates to measure the saturation voltage across the transistor and provide a fault signal which indicates that the drive should be terminated. |
