新型电力系统具有高比例可再生能源和高比例电力电子设备（即“双高”）特征，其中可再生能源出力的随机性与系统惯性水平降低将导致电网面临高频次的频率波动风险，储能是解决电网调频困难的关键技术之一。本文以飞轮储能阵列为研究对象，包括惯量飞轮与高速飞轮两种储能单元，研究两者建模与运行策略，并结合电池储能提出了一种参与电网调频的全过程协调控制策略。首先，介绍了飞轮储能阵列的运行结构，惯量飞轮采用双馈异步电机，用于满足电网的高惯量支撑需求；高速飞轮采用永磁同步电机，用于满足电网的大容量储能需求。分别建立了两类电机的数学模型，针对电网调频功能研究飞轮的充放电控制策略：对于响应电网调频的正常工况，采用有功无功解耦的功率环控制策略，以实现对有功功率的控制从而改善电网频率；对于SOC越界而无法响应调频的工况，采用转速环的控制策略将飞轮转速调回正常区间。对惯量飞轮进行过载测试，结果表明该惯量飞轮表明具备短时输出大功率的能力，可以确保其在调频过程中起到惯量支撑作用。其次，针对储能系统网侧多并联变换器的环流问题，基于环流数学模型提出了一种环流抑制策略，可以同时有效抑制低频差模环流与零序环流。加入该环流抑制方法之后的系统控制特性发生变化，需要研究并网稳定性。为此，采用一种考虑耦合频率的多频模型对并网变换器系统的各个环节进行建模，该建模方法对于系统振荡情形可以准确计算出振荡频率。通过建模得到系统传递函数从而计算零极点，确保所设计的环流抑制器不影响原系统的并网稳定性，结合并网变换器的仿真结果验证了上述理论分析的正确性。最后，提出了一种混合储能系统参与电网调频的协调控制策略。在惯性响应阶段的频率恶化期，由惯量飞轮同时提供惯量与阻尼支撑；在一次调频阶段由高速飞轮出力，同时惯量飞轮退出调频以减小系统惯性，加快电网频率恢复；二次调频阶段由电池储能辅助火电机组进行调节。以该控制策略为基础，研究具体工况下不同惯量飞轮阵列容量对系统调频性能指标的影响，确定了最佳的惯量飞轮数量。最终的仿真结果表明，该混合储能系统能够依次完成惯性响应、一次调频与二次调频阶段的衔接与调节。

A new type of power system with high proportion of renewable energy and high proportion of power electronic equipment (i.e. "dual high") characteristics faces the risk of high-frequency frequency fluctuations in power grid due to the randomness of renewable energy output and the reduction of system inertia level. Energy storage is one of the key technologies to solve the difficulty of grid frequency regulation. This article takes the flywheel energy storage array as the research object, including two types of energy storage units: inertia flywheel and high-speed flywheel. The modeling and operation strategies of the two are studied, and a coordinated control strategy for the entire process of participating in grid frequency regulation is proposed in combination with battery energy storage.Firstly, the operating structure of the flywheel energy storage array is introduced. The inertia flywheel adopts doubly fed induction motor to meet the high inertia support requirements of power grid; The high-speed flywheel adopts permanent magnet synchronous motor to meet the high-capacity energy storage needs of power grid. Two types of motor mathematical models are established separately, and the charging and discharging control strategy of the flywheel is studied for the frequency regulation function of power grid. For the normal working conditions of responding to the frequency regulation of power grid, a power loop control strategy of active and reactive power decoupling is adopted to achieve control of active power and improve the frequency of power grid; For the condition where SOC exceeds the limitation and cannot respond to frequency regulation, the strategy of using speed loop is adopted to control the flywheel speed back to the normal range. Overload testing is conducted on the inertia flywheel, and the results show that it has the ability to output high power in a short period of time, which can ensure the inertia support during the frequency regulation process.Secondly, a circulating current suppression strategy based on the mathematical model is proposed for the circulating current problem of multiple parallel converters on the grid side of energy storage systems, which can effectively suppress both low-frequency differential mode circulating current and zero-sequence circulating current. After adding this circulation suppression method, the control characteristic of the system has changed, it is necessary to study the stability of grid connection. Therefore, a multi-frequency model considering coupling frequency is adopted to model each link of the grid connected converter system. This modeling method can accurately calculate the oscillation frequency for the system oscillation situation. By modeling, the system transfer function is obtained to calculate the zero and pole points, ensuring that the designed circulating current suppressor does not affect the grid connection stability of the original system. The correctness of the theoretical analysis is verified by the simulation results of the grid connected converter.Finally, a coordinated control strategy for the participation of hybrid energy storage system in grid frequency regulation is proposed. During the frequency degradation period of inertial response stage, the inertia flywheel provides both inertia and damping support simultaneously; During primary frequency regulation, the high-speed flywheel outputs power, while the inertia flywheel exits the frequency regulation stage to reduce system inertia and accelerate the frequency recovery of power grid; Secondary frequency regulation is regulated by battery energy storage assisted thermal power plant. Based on this control strategy, the influence of different inertia flywheel array capacities on the frequency regulation performance indicators of the system under specific operating conditions is studied, and the optimal number of inertia flywheels is determined. The final simulation results indicate that the hybrid energy storage system can sequentially complete the connection and adjustment of inertial response, primary frequency regulation, and secondary frequency regulation stages.