凭借高功率密度、长使用寿命、低维护成本、绿色环保等特点，飞轮储能系统在新能源发电、再生制动能量回收、电网调频和不间断供电电源等领域得到了越来越广泛的应用。本文围绕飞轮储能系统在电网电压故障和电机缺相故障时的运行控制进行了理论分析、仿真和实验研究，以提高飞轮储能系统在高转速、大功率工况下的运行控制可靠性。首先，论文分析了飞轮储能系统拓扑结构及运行机理，在建立静止坐标系数学模型的基础上，建立了基于4d-q变换的十二相永磁同步电机数学模型；深入地讨论了正常运行工况下基于4d-q变换模型的机侧和网侧变流器矢量控制策略。基于Matlab/Simulink平台，对飞轮储能系统正常充放电工况下的控制策略进行仿真验证。其次，论文对十二相永磁同步电机缺相故障后的磁动势和基于合成磁动势不变原则的容错控制策略进行了理论推导及分析。基于飞轮电机正常运行时的控制策略，针对电机一相缺相故障，提出了将绕组故障后同一套三相变流器切除和同一套绕组等效为单相永磁电机的电机容错控制策略；另外，针对等效单相永磁电机转矩二倍频波动分量问题，提出了电机磁阻转矩补偿方法。针对电机两相缺相故障，分别讨论了故障相是否同属一套三相绕组及故障相是否为正交两相的工况，对一相缺相故障时提出的电机容错控制策略进行了扩展理论推导和使用。通过Matlab/Simulink仿真，验证了所提容错控制策略的有效性和可行性。再次，论文分析了电网电压对称故障和不对称故障下飞轮储能系统的动态特性，针对电网电压对称故障，提出了一种基于功率平衡的机侧与网侧变流器协调控制方法；针对电网电压不对称故障，提出了一种基于正负序分量分离的机侧与网侧变流器协调控制方法；实现了飞轮储能系统的电网电压故障穿越。对所提故障穿越控制策略的可行性和有效性进行了仿真验证。最后，基于十二相永磁同步电机的飞轮储能系统实验平台开展了系统正常工况和故障工况下的充放电实验。实验结果验证了本文所提控制策略的有效性与可行性，飞轮储能系统可在电机缺相故障时实现容错控制。
Flywheel energy storage system (FESS) has been widely used in the fields of new energy generation, regenerative braking energy recovery, power grid frequency modulation and uninterruptible power supply relying on the characteristics of high power density, long service life, low maintenance cost and green environmental protection. In order to improve the operation reliability of FESS under high speed and high power conditions, simulation and experimental research on the operation control of FESS during grid voltage fault and motor phase fault are focused on in this thesis.Firstly, the topology and operation mechanism of FESS are analyzed. By adopting the mathematical model of stationary coordinate system, a mathematical model of twelve-phase permanent magnet synchronous motor (PMSM) based on 4d-q transform decoupling is established. A vector control method of the motor based on the 4d-q decoupling model and a vector control method of the grid side converter under normal operating conditions are proposed. The control scheme of the FESS under normal charging and discharging conditions is simulated and verified by Matlab/Simulink platform.Secondly, the theoretical derivation and analysis of the magnetomotive force of one-phase phase fault and the fault-tolerant control strategy based on the principle of invariant synthetic magnetomotive force are carried out. Aiming at the situation of one-phase phase fault of the motor, two fault-tolerant control strategies based on the control strategy of flywheel motor during normal operation for removing the same set of three-phase converters after the winding fault and the same set of windings as a single-phase permanent magnet motor are launched. In addition, for the twice frequency fluctuation component of torque produced by equivalent single-phase permatnent magnet motor, a method of compensation using the reluctance torque is proposed. For the two-phase phase faults of the motor, the faulted phase classification of three-phase windings and orthogonal two-phase operating conditions is discussed respectively. The fault-tolerant control strategy of one-phase phase fault is theoretically derived and used. The effectiveness and feasibility of the proposed fault-tolerant control strategy are verified through simulation.Then, the dynamic characteristics of FESS under symmetric and asymmetric grid voltage faults are analyzed. Aiming at the symmetric fault of the grid voltage, a coordinated control method on the basis of power balance between the motor side and the grid side converter is proposed; Aiming at the asymmetric fault of the grid voltage, a coordinated control method of generator side and grid side converters based on the separation of positive and negative sequence components is proposed. Grid voltage fault ride-through control could be realized by FESS. The simulation verifies the feasibility and effectiveness of the proposed fault ride-through control strategy.Finally, the experiment platform of FESS based on twelve-phase PMSM is utilized to test the charge and discharge process under normal and fault conditions. The experimental results verify the effectiveness and feasibility of the proposed control scheme, for which indicades that FESS can operate reliably during fault-tolerant operation.
