Electric vehicle charger based on single-cycle control strategy

Abstract

The invention discloses a novel electric automobile battery charger based on a single-cycle control strategy, which comprises a three-phase power source connected with an LCL filter, wherein the LCL filter is connected with an input end of a main circuit of a three-phase PWM (Pulse-width Modulation) power converter; a DC output end of the three-phase PWM power converter is connected in parallel with a support capacitor, while a first load and a discharge loop are connected in parallel to the DC output end of the three-phase PWM power converter through a selective switch; and a control system of the three-phase PWM power converter acquires induction current signals of an LCL filter, voltage signals of the connection point of the input end of the main circuit of the three-phase PWM power converter with the LCL filter and DC voltage signals of the support capacitor C and controls the three-phase PWM power converter to operationally output corresponding pulse switch signals. The electric automobile battery charger has the advantages of simplicity in controlling, high response speed, low manufacturing cost, and capability of realizing seamless switch between rectification and inversion.

Description

technical field [0001] The invention relates to an electric vehicle charger based on a single-cycle control strategy. Background technique [0002] Electric vehicle chargers are nonlinear loads, which generate harmonic currents during charging, causing voltage distortion. At present, eliminating and suppressing current harmonics has become a hot spot in electric vehicle chargers. [0003] 1. Three-phase PWM power converters are widely used in electric vehicle chargers due to their sinusoidal grid-side current, high power factor, and bidirectional energy flow. The control strategies for three-phase PWM power converters include hysteresis control, predictive control, vector control, direct power control, etc., but these control methods all need to use dq coordinate transformation and SPWM or SVPWM modulation, the system is relatively complex, and the production cost is high. [0004] 2. The single-cycle control circuit has a compact structure, few components and fast respons...

AI Technical Summary

Problems solved by technology

The control strategies for three-phase PWM power converters include hysteresis control, predictive control, vector control, direct power control, etc., but these control methods all need to use dq coordinate transformation and SPWM or SVPWM modulation, the system is relatively complex, and the production cost is high

[0004] 2. The single-cycle control circuit has compact structure, few components and fast response speed, but there are limitations of unstable system operation under light load or reverse-phase inverter mode, and there are many difficulties in applying it to electric vehicle chargers

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