永磁同步电机飞轮储能系统充放电控制策略

Control Strategy for Flywheel Energy Storage System with Permanent Magnet Synchronous Machine

针对飞轮储能系统(FESS)转动惯量大、采用传统矢量控制算法启动时在零速附近容易出现转速震荡的问题,提出了一种新的电机控制方法。该方法用理论计算转速替代模型参考自适应(MRAS)算法的观测转速,并用给定电流替代反馈电流对耦合项进行计算,减小电机转速振荡。在FESS放电时,需要根据负载所需功率调整电机输出功率,针对此问题,采用一种以维持直流母线电压恒定为目标的电机控制方法,同时在FESS投入工作前,用电机当前转速作为传统MRAS算法PI控制器积分项的初始值,加快了MRAS无速度算法的收敛速度。仿真和实验结果表明,与传统控制方法相比,所提出的控制算法能减小电机启动时在零速附近的转速振荡,维持FESS放电时负载的正常工作,保证FESS快速可靠地进行状态切换。

When the flywheel energy storage system （FESS） begins to be charged at stationary state, due to the large inertia and low speed acceleration of the FESS, the speed may fluctuate in conventional vector control schedule. To solve this problem, a new strategy is proposed to reduce the speed fluctuation by taking the calculated speed instead of the observed speed from the model reference adaptive system （MRAS） algorithm and by replacing the feedback current with the reference current. When the FESS is discharged, the output power of the motor ought to be adjusted according to the load demand, and a motor control algorithm is advanced to keep the DC voltage at a certain level for this purpose. Before the FESS operating, the current motor speed is used as the initial integral value of the conventional PI controller to facilitate increasiing the convergence rate of MRAS algorithm. Compared with the conventional control schedule, the proposed strategy enables to minimize the speed fluctuation near zero speed when the FESS is charged form stationary state, and to keep the normal load working when the FESS is discharged, thus the FESS is ensured to switch into another state auicklv and reliably.