Energy-saving system and control method of unified power quality controller

Abstract

The invention provides an energy-saving system of a unified power quality conditioner (UPQC) and a controlling method thereof. During normal running, an anti-parallel thyristor is triggered and conducted; a series isolation transformer and a series current converter are in a bypass state; and a load current flows through the anti-parallel thyristor and a trigger pulse of the series current converter is blocked. When a voltage swelling or voltage dip phenomenon at a system side is detected, the anti-parallel thyristor is turned off by a forced way within short time, the load current flows through the primary side of the series isolation transformer, and the series current converter carries out compensation on the voltage swelling or voltage dip of the system side, so that the voltage of the load side goes back to normal. When the voltage of the system side goes back to normal, a trigger pulse is sent to the anti-parallel thyristor, so that the anti-parallel thyristor is conducted; and then the series isolation transformer and the series current converter are in a bypass state. Therefore, power losses of the series isolation transformer and the series current converter can be reduced, thereby realizing the energy conservation effect; and meanwhile, the compensation response time of the series portion of the UPQC is not influenced basically by controlling on and off of the thyristor in a forced mode.

Description

technical field [0001] The invention relates to the technical field of electric power protection control, in particular to an energy-saving system with a unified power quality controller and a control method thereof. Background technique [0002] Unified Power Quality Conditioner (UPQC for short) is a power quality control device based on power electronics technology, which integrates the characteristics of dynamic voltage restorer, static synchronous compensator, active filter and other devices. UPQC is mainly composed of two parts, a series converter and a parallel converter, which transmit energy through the DC bus. The UPQC series part is mainly used to solve voltage-type quality problems, such as voltage swell / sag, and the latter can mainly solve current-type power quality problems, such as harmonic current, reactive current, three-phase unbalanced current, etc. [0003] Like other power electronic devices, although the unified power quality controller has excellent co...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem that the loss of the unified power quality controller is too high, the present invention proposes an energy-saving system and control method of the unified power quality controller that makes the unified power quality controller more energy-saving

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