EXCITATIVE SYSTEM FOR ELECTRIC GENERATOR DOUBLY CONTROLLED IN PULSE WIDTH MODULATION METHOD AND CONTROL METHOD THEREOF

摘要

PURPOSE: An excitative system for an electric generator doubly controlled in a Pulse Width Modulation(PWM) method and a control method thereof are provided to vary the selecting width of a following time by adjusting the period of a saw teeth wave generator. CONSTITUTION: Signals controlling the outputs of excitative systems in operation and in waiting are compared for deciding if increasing or decreasing the value of the signal of an automatic voltage standard fed to the waiting excitative system. And, the difference of the signals controlling the outputs of the excitative systems and the saw teeth wave generated by a saw teeth wave generator are compared. If the value of the signal of automatic voltage standard fed to the waiting excitative system is decided to be increased, the value of the signal of the automatic voltage standard fed to the waiting excitative system is increased for the period having a larger value of the difference than the saw teeth wave. Also, if the value of the signal of automatic voltage standard fed to the waiting excitative system is decided to be decreased, the value of the signal of the automatic voltage standard is decreased for the period having smaller value of the difference than the saw teeth wave.