可再生能源自身出力具有波动性和随机性，导致电力系统面临越来越严重的频率稳定问题。在传统电网中，同步发电机等可以向电网提供惯性，而高比例可再生能源并入电网引入了大量电力电子装置，导致了电力系统面临着惯性和阻尼严重不足的问题。飞轮储能具有高功率密度、循环寿命长、绿色无污染的特点，适合解决电力系统面临的惯性和频率稳定问题。本文开展了将飞轮储能和电池储能组成混合储能系统的惯性响应和调频控制研究，研究了在常规工况下的建模、控制及电网调频需求下的惯性频率响应控制策略。首先，建立了自然坐标系及 双解耦变换、空间矢量解耦变换下飞轮储能系统双三相永磁同步电机的数学模型。基于 双解耦变换，研究了两种充放电控制模式：机侧转速外环、网侧直流母线电压外环和机侧直流母线电压外环、网侧功率外环控制策略，分析了其优缺点和应用场景。基于空间矢量解耦变换，研究了引入虚拟电压矢量的双三相永磁同步电机模型预测控制，分析了其性能特点，并进行了仿真验证。其次，分析新型电力系统的惯性支撑和调频需求，提出了一种飞轮-电池混合储能系统参与电网惯性响应的控制方法：考虑飞轮惯性、飞轮SOC和电网频率状态，提出飞轮储能惯量模拟控制策略；考虑电网阻尼需求、飞轮SOC恢复，提出了电池阻尼模拟控制策略。仿真结果表明该策略在系统频率突增、连续负荷扰动、阵列运行下，有效抑制了系统频率变化率，减小了频率偏差，验证了上述控制策略的有效性和正确性。再次，根据新型电力系统在不同时间尺度上的频率调节需求，提出了一种飞轮-电池混合储能系统参与电网频率调节的协调控制策略：考虑飞轮储能适合提供短时高功率的特点，确定了飞轮储能参与电网惯性响应、一次调频阶段频率调节控制策略；根据电池储能适合提供长时间功率的特点，确定了电池储能与飞轮储能配合参与电网一次调频，与电池储能配合参与电网二次调频阶段频率控制的控制策略，通过仿真验证了上述控制策略的有效性和正确性。最后，在双三相永磁同步电机飞轮储能实验平台上进行了实验研究，通过兆瓦级充放电测试，证明了本文提出的飞轮储能控制策略的有效性。
The output of renewable energy has volatility and randomness, which leads to more and more serious frequency stability problems in power system. In traditional power grid, synchronous generators can provide inertia to the power grid. With a high proportion of renewable energy integrating into the power grid, a large number of power electronic devices are introduced, which resulting in serious shortage of inertia and damping of the power system.Flywheel energy storage has the characteristics of high power density, long cycle life, green and pollution-free. It is suitable to solve the problems of inertia and frequency stability faced by power system. In this paper, the inertial response and frequency regulation control of hybrid energy storage system composed of flywheel energy storage and battery energy storage are studied. The modeling and control under normal working conditions and the inertial frequency response control strategy under the demand of power grid frequency modulation are studied.Firstly, the mathematical models of dual three-phase permanent magnet synchronous motor in flywheel energy storage system under natural coordinate system, decoupling transformation and space vector decoupling transformation are established. Based on decoupling transformation, two charge discharge control modes are studied: speed outer loop on motor-side, DC bus voltage outer loop on grid-side; DC bus voltage outer loop on motor side and power outer loop on grid-side. Their advantages, disadvantages and application scenarios are analyzed. Based on space vector decoupling transformation, the model predictive control of dual three-phase permanent magnet synchronous motor with virtual voltage vector is studied, its performance characteristics are analyzed and verified by simulation.Secondly, the inertia support and frequency modulation requirements of the new power system are analyzed, and a control method of flywheel battery hybrid energy storage system participating in grid inertia response and frequency regulation is proposed: Considering flywheel inertia, flywheel SOC and grid frequency state, a flywheel energy storage inertia emulation control strategy is proposed; Considering the demand of power grid primary frequency regulation and flywheel SOC recovery, a battery damping emulation control strategy is proposed. The simulation results show that the strategy effectively suppresses the system frequency change rate and reduces the frequency deviation under the sudden increase of system frequency, continuous load disturbance and array operation, which verifies the effectiveness and correctness of the above control strategy.Thirdly, according to the frequency regulation requirements of the new power system on different time scales, a coordinated control strategy of flywheel battery hybrid energy storage system participating in power grid frequency regulation is proposed: considering the characteristics that flywheel energy storage is suitable for providing short-term high power, the frequency regulation control strategy of flywheel energy storage participating in power grid inertia response and primary frequency regulation is determined; According to the characteristics that battery energy storage is suitable for providing power for a long time, the control strategy of battery energy storage cooperating with flywheel energy storage to participate in the primary frequency regulation of power grid and cooperating with battery energy storage to participate in the frequency control in the secondary frequency regulation stage of power grid is determined. The effectiveness and correctness of the above control strategy are verified by simulation.Finally, the experimental research is carried out on the flywheel energy storage experimental platform of dual three-phase permanent magnet synchronous motor. The megawatt charge discharge test proves the effectiveness of the flywheel energy storage control strategy proposed in this paper.
