초록 ▼

A power converter for driving an AC motor includes a main circuit and a control circuit such that: the main circuit includes a forward conversion circuit that forwardly converts AC power from an input AC power source into DC power, and an inverter circuit that inversely converts the thus forwardly c

A power converter for driving an AC motor includes a main circuit and a control circuit such that: the main circuit includes a forward conversion circuit that forwardly converts AC power from an input AC power source into DC power, and an inverter circuit that inversely converts the thus forwardly converted and smoothed DC power into AC power of a specified voltage and frequency; the control circuit includes a calculation device that calculates a torque current component of the AC motor, a detection device that detects occurrence of an instantaneous interruption in the AC power source, a command device that commands a frequency to be fed into the AC motor, a control device that receives a signal relative to an output signal of the command device so as to control a terminal voltage of the AC motor, and a compensation device that adjusts the output signal of the command device so that the output signal of the calculation device is caused to be substantialloy zero in response to the output signal of the detection device.

대표청구항 ▼

A power converter for converting a first AC power from an AC power source to a second AC power for a load comprising: forward conversion means, connected to the AC power source, for converting said first AC power into a DC power; filter means, connected to the forward conversion means and including

A power converter for converting a first AC power from an AC power source to a second AC power for a load comprising: forward conversion means, connected to the AC power source, for converting said first AC power into a DC power; filter means, connected to the forward conversion means and including at least a capacitor, for filtering said DC power; inverter means, connected to the filter means, for converting the DC power into said second AC power and adapted for driving the load; calculation means, coupled to said second AC power, for calculating a torque current component of the load from a voltage and a current thereof; detection means for detecing an occurrence of an instantaneous interruption in the AC power source and producing an output signal indicative thereof; command means, coupled to said inverter means, for commanding a frequency of said second AC power by producing a command output signal; control means, coupled to said command means and said inverter means, for controlling said voltage of said load in accordance with said command output signal of said command means and a reference value; and first compensation means for compensating the command output signal of said command means so that said torque-current component of the load as indicated by the output signal of said calculation means becomes substantially zero in response to said output signal of said detection means.