초록 ▼

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

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.

대표청구항 ▼

A system characterized by: a motor, an inverter, for operating the motor, having one or more output power transistors, an inverter control for providing a drive signal to drive each transistor, inverter protection means for providing power to a portion of the inverter control and removing said power

A system characterized by: a motor, an inverter, for operating the motor, having one or more output power transistors, an inverter control for providing a drive signal to drive each transistor, inverter protection means for providing power to a portion of the inverter control and removing said power to turn off said transistor drive in response to a particular transistor operating condition of one of the transistors that occurs during one or more pre-established time intervals while the drive signal is applied; said inverter protection means comprising means for removing said power if the time it takes for the transistor collector-emitter voltage to drop to the transistor\s saturation voltage after the drive signal is applied exceeds a certain predetermined time interval.