UTILITY INTERACTIVE INVERTER OF THREE PHASE-INDIRECT CURRENT CONTROL TYPE AND CONTROL METHOD

摘要

PURPOSE: A control method of a three phase-indirect current control type utility interactive inverter is provided to maintain uniform size and frequency of voltage at critical loads by compensating voltage at the critical loads. CONSTITUTION: A target value of an inverter output current is obtained from a target power value applied to a system. A voltage required for both ends of a filter capacitor is obtained according to the target value. An error is calculated by comparing the target value with the actual current. An external loop controller calculates a voltage compensation value required for both ends of the filter capacitor using the error. A target value of voltage required for both ends of the final filter capacitor is obtained by adding the voltage required for both ends of the filter capacitor to the voltage compensation value. A voltage error is calculated by comparing the target voltage value with the actual voltage at both ends of the filter capacitor. An internal loop controller calculates the final voltage compensation value using the voltage error. A pulse width modulation signal is output based on the final voltage compensation value.