SYSTEM INTERCONNECTION TYPE INVERTER CONTROLLER

摘要

PURPOSE: To prevents backflow of a current or a transient current by setting an inverter output voltage equal to or several volts higher than the commercial system voltage when linking the commercial system power source to a systems interconnection type inverter controller. CONSTITUTION: A signal transfer section 18 selects an inverter output voltage detecting signal (d) as a feedback signal during starting. This feedback signal is compared to a reference sine wave signal (b) generated by a signal arithmetic processing unit 19 in an error amplifier 17. This result is output to the PWM controller 16, and the amplitude of the signal (d) is made equal to the amplitude of the signal (b). Amplitude of the signal (b) is determined in such a manner that the inverter output voltage becomes equal to or several volts higher than the setting voltage for the commercial system voltage. The signal arithmetic processing unit 19 outputs the signals for closing an interconnection relay 10 and also outputs signals for transferring the feedback signals from signal (d) to inverter output current detecting signal (c) to the signal transfer section 18.