DESIGN OF SERIES SILICON-CONTROLLED RECTIFIER INVERTER.

摘要

There are two methods by which switches of similar devices can be used to generate AC. In a parallel inverter circuit, a constant current source is used and the switches are used to pass square waves of constant current. In a series inverter circuit, a constant voltage source is used and the switches are used to pass halfsine waves of current. A series inverter in which siliconcontrolled rectifiers were used as the switching elements was designed and constructed for this thesis. Siliconcontrolled rectifiers can be used for generating high power frequencies up to 10 kilocycles per second. However,because of cost considerations,the series inverter that was designed was a low power 400cycles per second inverter. The same design criteria can be used to generate much higher frequencies and outputs of several KVA. An important requirement for the inverter is that the timing pulses for one silicon-controlled rectifier occur midway between the timing pulses for the other silicon-controlled rectifier. A bistable multivibrator triggered by a unijunction transistor relaxation oscillator of 800pulses per second was used to satisfy this requirement. A transformer was connected in series with the series resonant circuit. The silicon-controlled rectifiers switched half-sine waves of current alternately through the primary and the output sine wave of voltage was taken from the secondary. (Author)