风储系统中储能SOC优化控制方法研究

发布时间：2018-05-11 13:33

本文选题：风储系统 + 功率波动平抑　；参考：《电子科技大学》2014年硕士论文

【摘要】：为风电场配置储能系统是解决风电输出功率波动性和间歇性问题的主要手段,但是,在利用储能系统平抑风电功率波动的时候,无法保证对其进行有规律的充放电,容易出现过充过放,这不仅会影响储能系统的使用寿命,而且在功率波动剧烈时可能会使其充放电能力不足,影响风电并网运行的安全。如果在制定储能系统的充放电策略时,加入对其荷电状态(SOC)的额外控制,就可以在平抑风电场功率波动的同时,避免储能系统的过充过放,使其能够长期平滑风电场的输出功率。因此,研究风储系统中储能SOC的控制方法是十分重要的。本文针对基于全钒液流电池(VRB)的风储联合发电系统,研究了一种储能SOC的优化控制方法,主要工作如下:1.研究了风储系统的结构,并分析了风电功率波动特性,阐述了储能平抑风电场功率波动的原理。研究了基于VRB的储能系统等效模型,并对其充放电特性进行了分析。2.设计了储能SOC优化控制方法的控制结构,主要包括最优SOC计算模块和SOC实时控制模块。最优SOC计算模块根据风电场未来一段时间的预测功率计算最优SOC范围,该范围要保证储能系统有足够的充放电能力来平抑未来一段时间的功率波动;SOC实时控制模块为储能系统制定合理的充放电策略,使其在平抑当前功率波动的同时,将SOC逐渐调整到最优SOC范围之内。3.研究了基于目标优化的最优SOC计算算法,通过建立目标优化模型来计算储能系统的最优SOC范围。该目标优化模型以最小化储能系统的过充过放时间和最大化最优SOC范围的可达性为目标函数,考虑了电网对风电场功率波动的约束,并采用粒子群算法对目标优化模型进行求解。4.研究了基于滤波时间常数模糊自调整的储能SOC实时控制策略。该控制策略采用基于低通滤波原理的功率平抑方法,通过对储能SOC的实时反馈来调整滤波器的时间常数,进而调整储能系统的设定功率,最终达到控制SOC的目的。5.利用仿真软件PSCAD和MATLAB对储能SOC的优化控制方法进行了仿真验证,分别针对三种不同功率波动情况下的控制效果进行了对比分析,结果表明,本文所研究的储能SOC优化控制方法可以在保证功率波动平抑效果的同时,有效地避免储能系统的过充过放,使其长期平滑风电场的输出功率。
[Abstract]:Installing energy storage system for wind farm is the main method to solve the problem of fluctuation and intermittency of wind power output. However, when the energy storage system is used to stabilize the fluctuation of wind power, it cannot be guaranteed to charge and discharge it regularly. It is easy to overcharge and overdischarge, which will not only affect the service life of the energy storage system, but also may make the charging and discharging capacity insufficient when the power fluctuation is severe, and affect the safety of wind power grid connection. If additional control is added to the charging and discharging strategy of the energy storage system, the excess charge and overdischarge of the energy storage system can be avoided while suppressing the fluctuation of the power of the wind farm. Make it possible to smooth the output power of the wind farm for a long time. Therefore, it is very important to study the control method of energy storage SOC in air storage system. In this paper, an optimal control method of energy storage SOC is studied for a combined wind storage generation system based on a vanadium liquid flow battery. The main work is as follows: 1. In this paper, the structure of wind storage system is studied, and the characteristics of wind power fluctuation are analyzed, and the principle of energy storage to stabilize the power fluctuation of wind farm is expounded. The equivalent model of energy storage system based on VRB is studied, and its charge-discharge characteristics are analyzed. The control structure of the optimal control method for energy storage SOC is designed, including the optimal SOC calculation module and the SOC real-time control module. The optimal SOC calculation module calculates the optimal SOC range according to the predicted power of the wind farm for some time to come. This range should ensure that the energy storage system has sufficient charge-discharge capacity to stabilize the power fluctuation in the future. The SOC real-time control module can make reasonable charging and discharging strategy for the energy storage system, so that it can stabilize the current power fluctuation at the same time. Gradually adjust the SOC to the optimal SOC range. 3. 3. The optimal SOC algorithm based on objective optimization is studied, and the optimal SOC range of energy storage system is calculated by establishing an objective optimization model. The objective optimization model takes minimization of overcharging time of energy storage system and maximization of reachability of optimal SOC range as objective functions, and the constraints of power fluctuation of wind farm are considered. Particle swarm optimization algorithm is used to solve the target optimization model. The real-time control strategy of energy storage SOC based on filtering time constant fuzzy self-adjustment is studied. The control strategy adopts the power suppression method based on the principle of low-pass filter, adjusts the time constant of the filter through the real-time feedback of the energy storage SOC, and then adjusts the set power of the energy storage system, and finally achieves the purpose of controlling the SOC. 5. The simulation software PSCAD and MATLAB are used to verify the optimal control method of energy storage SOC. The control effects of three different power fluctuations are compared and analyzed respectively. The results show that, The energy storage SOC optimal control method studied in this paper can effectively avoid overcharging and over-releasing of the energy storage system and smooth the output power of the wind farm for a long time while ensuring the power fluctuation and stabilizing effect.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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