基于改进PSO算法的非理想电压条件下电力弹簧控制策略

电力弹簧(ES)的提出旨在实现用电量随发电量的变化而变化，可有效缓解新能源发电引起的间歇性问题，为关键负载(CL)提供稳定电能质量。然而当非理想电网(电压不平衡与低次谐波共存)时，ES采用传统比例-积分控制无法稳定CL电压，针对这个问题，首先提出一种基于四阶广义积分器的有源滤波器滤除电网中所含谐波并补偿CL母线的不平衡电流，保证CL电压和电流谐波含量符合要求且逆变器输出电流平衡。在此基础上，提出利用改进粒子群优化算法实时检测CL两端电压的不平衡度信息，实时优化串联非关键负载(NCL)的ES电压脉宽调制控制信号，使CL电压稳定且电能质量符合要求，以消除电网电压不平衡及波动的影响。最后，通过仿真不同负载工况，对所提算法进行了验证。

Control Strategy of Electric Spring Under Non-ideal Voltage Conditions Based on Improved PSO Algorithm

The purpose of electric spring(ES)can effectively alleviate the intermittent problems caused by new energy generation and provide stable power quality for critical loads(CL)by realizing the variance of electricity consumption with the change of power generation. However, ES adopts with the traditional proportional-integral(PI)control method and can not effectively stabilize the CL voltage under non-ideal grid voltages(voltage imbalance and low-order harmonics coexist). To solve this problem, the active power filter(APF)based on fourth-order generalized integrator(FOGI)is firstly developed, which can filter out the harmonics in the grid and compensate for the unbalanced current of the CL bus. The proposed method can meet the requirements of the CL voltage and current harmonics and can balance the output current in the inverter. Furthermore, the improved particle swarm optimization(PSO)algorithm is used to detect the unbalanced voltage information of CL two ends in real time, and optimize the pulse width modulation(PWM)control signal of ES voltage in series with non-critical load(NCL)to make the voltage across the CL stable and meet the requirements of the power quality, which would eliminate the impact of imbalance and fluctuations of grid voltage. Finally, the proposed algorithm is verified by simulating different load conditions.