A power converter apparatus for use in supplying power from a DC power source to a load, including a chopper connected to the DC power source; an inverter connected to a DC output of the chopper for supplying converted AC power to the load; an error amplifier for detecting an output voltage of the power converter apparatus and controlling the output voltage so as to maintain the output voltage equal to a predetermined reference value; and a voltage control circuit for generating a gate signal for the chopper, including an oscillator circuit for producing a variable frequency signal having a frequency varied in accordance with an output signal of the error amplifier, and a phase shifter for producing the gate signal with a pulse width varied in synchronism with the output signal of the oscillator circuit and for applying the pulse width varied gate signal to the chopper. In this way the chopper frequency is decreased to improve the operating efficiency during light-load operation.

Power converter apparatus including a chopper regulated inverter system

According to the invention, the system comprises a resonance type inverter, a diode rectifier bridge and single regulation loop controlling controlled switching means, forming a chopper, interconnected between the rectifier bridge and the inverter. The system is applied to X-ray equipment.

Input regulated high voltage D.C. power supply system

The invention concerns the transformation of alternating or direct current input power to alternating current output power with intermediary transformation in direct current by means of static converters. According to the invention, an adapter placed in the direct current intermediary circuit (4) comprises a branch connected between the output terminals of the input converter (5), and contains in series a free wheel thyristor (18) and an inductance (16) whose value is equal to the total loss inductance of the motor (1) connected to the reversible output inverter (20). The purpose is to reduce the current wave harmonics in the power supply.

Adapter for intermediary circuit of a static converter assembly

Single-phase frequency converter

The present invention is an AC--AC converter device comprising a converter circuit capable of producing an instantaneously varying output voltage, and a coupled reactor commutating inverter circuit cascade-connected thereto, the inverter circuit having a plurality of thyristors which are rendered conductive in a predetermined sequence, in which the output voltage of the converter circuit is rendered positive, negative or zero as necessary to effect commutation and current control in the inverter circuit.

Tunghai Chin

Papers

AC-AC Converter device