虚拟同步发电机频率特性与储能设备容量及充放电特性的关系

Relationship Between Frequency Characteristics of Virtual Synchronous Generator and Parameters of Energy Storage Equipment

虚拟同步发电机(virtual synchronous generator,VSG)没有实际的转子,而是通过控制算法模拟实现实际转子的转动惯量和阻尼特性,本质上依赖于储能容量及其充放电特性。基于VSG原理,推导出VSG在输入功率和电网频率变化时的频率特性与所需要的储能容量之间的关系式,据此揭示了VSG虚拟惯性系数、阻尼系数和频率特性与储能容量及其充放电特性之间的关系,并分析了储能设备容量不足对VSG输出特性的影响,提出了一种满足VSG频率特性要求的储能配置方法。仿真结果验证了VSG虚拟惯性系数、阻尼系数、频率特性和储能需求之间的关系,表明VSG预期输出特性的实现需要有合适的储能容量及其充放电特性予以支撑。

Virtual synchronous generator(VSG) does not have actual rotor, and it’s designed to simulate rotor inertia and damping characteristics by the control algorithm, but which are essentially dependent on capacity and charging-discharging characteristics of VSG energy storage equipment. Therefore, the relationship between the VSG frequency characteristics and the required energy storage capacity under the changing of the input power or the grid frequency is deduced based on the principle of VSG. The relationship between VSG virtual inertia coefficient, damping coefficient and frequency characteristic and energy storage capacity and its charging-discharge characteristic is revealed. The influence of insufficient capacity of energy storage equipment on the output characteristic of VSG is analyzed, and an energy storage configuration method satisfying the frequency characteristic of VSG is proposed. The relationship between VSG virtual inertia coefficient, damping coefficient, frequency characteristic and energy storage demand is verified by simulation, which shows that the realization of VSG expected output characteristic needs to be supported by appropriate energy storage capacity and charge and discharge characteristic.