应用于储能逆变器中网侧继电器拓扑、自检方法和能量控制策略

Applied to Grid-Side Relay Topology, Self-Test Method, and Energy Control Strategy in Energy Storage Inverters

摘要: 本文提出了一种储能逆变器网侧继电器拓扑结构及其自检方法与能量控制策略。该拓扑采用三只双触点继电器(RY1, RY2, RY3)分为两个组合：第一组合由RY2和RY3的常开触点串联构成储能逆变器交流侧母线与电网之间的电气通道；第二组合由RY1单独构成逆变器输出端与交流侧母线之间的通道。通过控制继电器线包通断电，检测组合继电器两侧电压有效值差值，据此准确诊断出继电器触点是否存在短路或开路故障，从而实现网侧继电器自检方法。在此基础上，给出高效的市电掉电快速检测方法，进而实现储能逆变器由并网到离网的快速切换，并实现安全、快速的能量控制，确保后备负载连续供电。搭建了5 kW储能逆变器实验平台，实验结果证明本文提出的网侧继电器拓扑及其自检方法与能量控制策略的有效性。

Abstract: The paper proposes a grid-side relay topology structure for energy storage inverters, as well as its self-checking method and energy control strategy. This topology employs three double-contact relays (RY1, RY2, RY3) divided into two combinations: The first combination consists of the normally open contacts of RY2 and RY3 connected in series to form an electrical channel between the AC side of the inverter and the power grid. The second combination is composed of RY1 alone, which forms the channel between the inverter output terminal and the AC bus. The self-check method accurately diagnoses short circuit or open circuit faults of the contacts by controlling the on and off of the relay coil and detecting the difference in effective values of the voltages on both sides of the combined relay, thereby achieving highly reliable self-check. By integrating efficient rapid detection technology for power failure, this strategy can achieve safe and rapid energy control during the grid-connected and off-grid switching process, ensuring continuous power supply to the backup load. An experimental platform for a 5 KW energy storage inverter was established. The experimental results proved the correctness of the topological structure, self-checking method and energy control strategy proposed in this paper.