虚拟同步机运行状态下并网储能系统自动能量控制

Automatic Energy Control of Grid-connected Energy Storage System Under Virtual Synchronous Generator Operation

虚拟同步机控制可以模拟同步机的惯性、阻尼和调频特征。针对虚拟同步机运行状态下储能系统的能量调节问题,提出了自动能量控制方法,将储能荷电状态(SOC)负反馈加入虚拟同步机控制的角频率指令值,使储能系统能量相对其指令值的偏差自动跟踪角频率指令值相对其额定值的偏差。储能系统可以在其储能容量限额范围内自动进行充放电以抑制电网频率波动,避免储能电池过度充放电而损坏。在电网二次调频作用下,储能系统能量也将自动恢复至其指令值。自动能量控制仅使用本地控制量,不依赖额外的通信系统,也无须测量电网频率。自动能量控制取消了传统能量控制SOC负反馈的积分环节,避免了SOC控制超调。通过时域仿真验证了储能系统自动能量控制的效果。

The control of virtual synchronous generator can simulate the inertia,damping and frequency regulation characteristics of the synchronous generator.Aiming at the energy regulation problem of the energy storage system(ESS)under virtual synchronous generator operation,the automatic energy control method is proposed.The negative feedback of the state of charge(SOC)of the ESS is added to the angular frequency command value of the virtual synchronous generator control,so that the deviation of the ESS energy from its command value can automatically track the deviation of the angular frequency command value from its rated value.The ESS can automatically charge and discharge within the limit of its energy storage constraints to suppress the fluctuation of power grid frequency,and avoid the damage to the energy storage battery due to excessive charging and discharging.Under the operation of secondary frequency regulation of the power grid,the energy of the ESS will also automatically recover to its command value.Automatic energy control only uses local control quantities without additional communication system or grid frequency measurement.The integral term of SOC negative feedback of the traditional energy control is canceled,and the overshoot of SOC control is avoided by the automatic energy control.The effect of the automatic energy control of ESS is verified by time-domain simulation.