초록 ▼

The logic control system of the invention regulates the frequency of operation of an inverter which drives an electric motor, and also regulates the level of the d-c bus voltage supplied to the inverter. This is accomplished by sensing the level of the bus voltage and the level of the current suppli

The logic control system of the invention regulates the frequency of operation of an inverter which drives an electric motor, and also regulates the level of the d-c bus voltage supplied to the inverter. This is accomplished by sensing the level of the bus voltage and the level of the current supplied to the motor, and comparing the sensed values to a reference or set point signal. The motor drives a compressor, and a capacity control system cooperates with the logic control system in the regulation of the compressor. The capacity control system provides signals, such as start/stop and inverter set point, to the logic control system to assist in regulating operation of the inverter which drives the compressor. In particular the logic control system includes a reference conductor on which a basic reference control signal is developed for use in controlling both the amplitude and the frequency of the a-c energy supplied by the inverter to the motor.

대표청구항 ▼

A logic control system for an inverter connected to drive an electric motor which in turn drives a load, the inverter providing an a-c voltage over an output line to the motor upon receipt of a d-c voltage over a d-c bus, which logic control system comprises: a reference conductor on which a referen

A logic control system for an inverter connected to drive an electric motor which in turn drives a load, the inverter providing an a-c voltage over an output line to the motor upon receipt of a d-c voltage over a d-c bus, which logic control system comprises: a reference conductor on which a reference control signal is developed for use in regulating both the level of d-c voltage on the d-c bus and the frequency of the a-c voltage provided by the inverter; a ramp generator circuit coupled to the reference conductor, for providing a gradually increasing output signal during system start-up to function as the reference signal; and a capacity circuit, having an output portion coupled to the reference conductor and an input portion connected to receive a signal varying as a function of the inverter operating frequency, said output portion including components connected such that the reference control signal developed on the reference conductor is the lower of the output signals from the ramp generator circuit and the capacity circuit.