Active power equalization method of AC-DC-AC converter

Abstract

The invention discloses an active power equalization method of an AC-DC-AC converter, and relates to the technical field of electric energy quality management. The method comprises the steps: carrying out the rotation coordinate transformation of a load current, a compensation current and a grid-side current, and obtaining active components and reactive components of the load current, the compensation current and the grid-side current; processing active and reactive components of the load current, and then obtaining a compensation current reference value through rotational coordinate inverse transformation; carrying out PI operation on the compensation current reference value and the compensation current to obtain a primary compensation modulation wave; carrying out PI operation on the active and reactive components of the grid-side current, and then obtaining secondary compensation modulation waves through rotation coordinate transformation. According to the method, the modulation waves of the primary compensation and the modulation waves of the secondary compensation are added, the control signal of a converter is obtained through PWM modulation, control is carried out through the modulation waves of the secondary compensation, grid-side current unbalance can be rapidly compensated, the grid-side current unbalance degree is remarkably reduced, and the reliability and stability of a control system are enhanced.

Description

technical field [0001] The invention belongs to the technical field of electric energy quality control, and in particular relates to an active power balancing method of an AC-DC converter. Background technique [0002] At present, most of the civil loads in my country's low-voltage distribution network are mainly single-phase loads. Due to the randomness and volatility of power consumption by users, the distribution network often suffers from three-phase unbalanced problems. The unbalance of three-phase system will cause voltage and current to contain a large number of negative sequence and zero sequence components, which will affect the normal operation of electrical equipment. Therefore, three-phase unbalance compensation has become a research hotspot. [0003] With the development of power electronics technology, an AC-DC-AC converter is used to balance the active current of the three-phase grid, so that the current of the three-phase grid is in a balanced state. This ki...

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Problems solved by technology

[0004] The purpose of the present invention is to provide an active power equalization method of AC-DC-AC converter, thereby overcoming the disadvantage that the existing control method of AC-DC-AC converter cannot reduce the current unbalance degree of three-phase power grid

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