Common direct-current bus bidirectional converter with electric energy quality treatment function and control method thereof

Abstract

The invention discloses a common direct-current bus bidirectional converter and a control method thereof. The bidirectional converter mainly comprises an active and reactive controller, a CPS-SPWM controller and a plurality of converter modules. The control method mainly comprises the following steps: judging whether a load is accessed to a direct-current bus or not; if yes, detecting the number of converter modules connected to the system; judging whether an alternating-current power grid needs active feedback or not; if the alternating-current power grid does not need active feedback, controlling all the modules connected to the system in a voltage and current double-closed-loop mode, controlling all the modules through the same reference voltage, or else, averagely distributing active power needing to be fed back to all the working converter modules, changing the feedback current direction of the working converter modules, and then adopting power outer-loop current and inner-loop double-closed-loop control; when no load exists, judging whether the alternating-current power grid needs electric energy quality management or not, and if yes, adopting a voltage and current double-closed-loop control method under a d-q coordinate system, and adding reactive power and harmonic waves needing to be output into current loop control; and if not, only keeping the direct-current voltage.

Description

technical field [0001] Embodiments of the present invention relate to a bidirectional converter, in particular, to a common DC bus bidirectional converter with power quality control and a control method thereof. Background technique [0002] Due to the continuous development of the electric vehicle industry, the charging of pure electric and plug-in hybrid electric vehicles has gradually become the focus of social development. Most charging stations use AC-DC (ie, rectification) to charge the power battery. The rectification link mostly uses a PWM rectifier, and its power flows in one direction, and then in the DC conversion charging link, the output is precisely adjusted according to the voltage, current or power demand of the load. [0003] At present, many AC or DC charging piles have begun to be used: [0004] In the first way, the DC charging pile is only used as a DC power supply. When multiple DC charging piles are arranged in parallel at the charging station, the m...

AI Technical Summary

Problems solved by technology

[0007] At present, the third method is relatively advanced, but it still has shortcomings, that is, it cannot realize the coordinated control of multiple parallel multiple bidirectional converters and realize power quality management.

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