Power conversion control system

Abstract

A power distribution system (10) comprises a power conversion module (12) for performing power conversion between a DC voltage at a DC side (14), an AC power at an AC side (16) and a conversion control system. The AC side of the power conversion module is electrically coupled to a grid (18). The conversion control system comprises a phase-locked-loop circuit (32) for receiving a multi-phase reference signal (40) of a grid voltage and for generating a synchronized signal (42), a regulator (52) for receiving reference commands, a two-phase grid feedback signal and the synchronized signal and for generating a control signal for the power conversion module and a phase compensation circuit (64) for receiving the synchronized signal and the multi-phase reference signal of the grid voltage, for obtaining a phase displacement signal (70), and for generating a phase compensation signal (66); for compensating the reference commands or for compensating the synchronized signal when the phase displacement signal exceeds a threshold value.

Description

technical field [0001] The present invention generally relates to power conversion control systems. Background technique [0002] A typical power distribution system includes a power conversion module including a DC side and an AC side, a power grid electrically coupled to the AC side of the power conversion module, a power distribution unit electrically coupled to the DC side of the power conversion module, and a Controlled conversion control system. Conversion control systems typically include phase-locked loop (PLL) circuitry for generating synchronized phase and frequency signals. [0003] PLL circuits are generally closed loop circuits and work well under substantially steady operating conditions of the power distribution system. However, when transient conditions such as low-voltage ride-through (LVRT), zero-voltage ride-through (ZVRT), or high-voltage ride-through (HVRT) occur, the grid voltage has large phase jumps, and the PLL circuit may not provide fast enough ...

AI Technical Summary

Problems solved by technology

However, when transient conditions such as low-voltage ride-through (LVRT), zero-voltage ride-through (ZVRT), or high-voltage ride-through (HVRT) occur, the grid voltage has large phase jumps, and the PLL circuit may not provide fast enough Response to prevent reverse flow of real power or possibly lead to inappropriate reactive power control in distribution systems

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