混合储能系统改善鼠笼式风电机组性能控制方法研究

This project launches a research on the coordinated control strategy of hybrid energy storage system to improve power quality, generator torque oscillation and low voltage ride through capability of wind turbine generation system with squirrel cage induction generator. The coordinated control strategy of hybrid energy storage system to improve power quality of wind turbine generation system with squirrel cage induction generator under the normal operation is studied. In order to effectively smooth wind power and prevent overcharge and over discharge of energy storage devices the target powers of system are adjusted dynamically based on the charged state of energy storage devices and multi-level fuzzy. The coordinated control strategy for improving dynamic torque is investigated under unbalanced fault to reduce the torque oscillations so as to reduce the mechanical stresses of gear box and drive train, and extend their lifetime. The coordinated control strategy is studied under balanced fault to increase low voltage ride through capability, and limit the generator electromagnetic torque during voltage recovery process. The smooth switching of the coordinated control strategy of hybrid energy storage system under different working conditions is investigated. The simulation model of whole system which contains both hybrid energy storage system and wind turbine generation system is established, and a small capacity physics experimental setup is built up. Furthermore, the correctness and feasibility of the proposed control strategies are verified by the simulation and experimental study. The research of this project provides the necessary theoretical fundamentals and technical support for the large scale integration of wind turbine generation system with squirrel cage induction generator into the grid, and has important theoretical significance and giant practical value.

本项目研究混合储能系统改善鼠笼式风电机组电能质量、发电机转矩脉动及低电压穿越能力的协调控制策略。研究正常运行下改善鼠笼式风电机组电能质量的混合储能系统协调控制策略，基于储能荷电状态和多层模糊控制动态调节储能系统目标功率，更好平滑风电功率同时防止储能过充过放；研究不平衡故障下改善鼠笼式风电机组动态转矩的协调控制策略，减小发电机转矩脉动，从而减小齿轮箱和传动装置的应力，延长其使用寿命；研究平衡故障下既能提高低电压穿越能力又能限制电压恢复期间发电机电磁转矩的协调控制策略；研究各种工况下可平滑切换的混合储能系统协调控制策略。建立包含混合储能系统和风电机组的完整系统仿真模型及搭建小容量的物理实验系统，通过仿真和实验研究验证所论控制策略的正确性和可行性。本项目的研究工作为鼠笼式风电机组大规模接入电网提供必要的理论依据及技术支撑，具有重要的理论意义及实际应用价值。

本项目主要研究混合储能系统改善鼠笼式风电机组电能质量、发电机转矩脉动及低电压穿越能力的协调控制策略。研究基于零相位低通滤波器的混合储能系统平抑笼型风电机组电功率波动控制策略，采用基于零相位低通滤波器风电功率分配算法，并给出参数优化设计方法，可实时准确地检测风电功率中高、中和低频功率，从而取得更好的平抑功率波动效果和减小储能单元的容量。研究基于DSP和AUKF的锂离子电池SOC估计方法，在SOC估计时对系统过程噪声和测量噪声的协方差进行实时预测和修正，进而提高SOC的估算精度。研究基于SOC反馈的混合储能系统协调控制策略，根据SOC动态调整电池和超级电容的目标功率，既可以很好的平抑风电功率波动，又避免了储能系统的过度充电和过度放电，延长蓄电池寿命。研究基于多组蓄电池SOC均衡的的混合储能平滑鼠笼式风电机组电功率控制策略，给出基于SOC偏差的多组蓄电池功率优化分配方法，在保证每组电池不超过额定充放电功率的情况下，实现SOC的快速均衡。研究平衡故障下提高鼠笼式风电机组低电压穿越能力和抑制转矩过高的混储能系统协调控制策略，通过控制DC/AC输出或吸收无功功率使公共连接点电压按转差率函数关系恢复，从而间接控制发电机电磁转矩，提高了鼠笼式风电机组低电压穿越能力。研究不平衡故障下改善鼠笼式风电机组动态转矩的混合储能系统正负序电压协调控制策略，DC/AC输出负序电流以补偿负序电压，从而减小发电机电磁转矩脉动，采用混合储能稳定DC/AC直流侧电压，吸收直流侧因负序电压引起的波动功率，从而减小直流侧电压的脉动。根据SOGI-FLL检测的公共链接点正负序电压幅值，实现故障下和正常情况下的控制策略的平滑切换。研制鼠笼式风电机组和混合储能系统的仿真和物理实验平台，验证理论分析的正确性。