PHASE SYNCHRONIZATION CONTROLLER FOR SERIES INSTANTANEOUS POWER-DROP COMPENSATING DEVICE

摘要

PROBLEM TO BE SOLVED: To shorten a time that is taken to synchronize a system voltage at power restoration with a load voltage.;SOLUTION: In a phase synchronization controller, a preset value of a load voltage setting unit 41 and a detected value of a load voltage V_LOAD are added to an adder 43, and a difference between the preset value and the detected value is determined as output from the adder 43. The determined difference is given to a PWM command value making unit 44, and a PWM command value is made in output from the PWM command value making unit 44. The made PWM command value is input to a comparing unit 46 via a variable gain unit 47 interposed in an electronic path connecting the PWM command value making unit 44 to the comparing unit 46. The variable gain unit 47 is so configured that a gain G is gradually changed with time from "1" to "0" by a power-restoring detected signal from a power-restoring signal detecting unit 48. When a power-restoring signal is detected, the gain G gradually changes as well from "1" to "0", which causes the PWM command value to reduce. This leads to output of an inverter gate signal that gradually reduces an output voltage from an inverter 33b to "0".;COPYRIGHT: (C)2009,JPO&INPIT