直流励磁发电系统电容电荷平衡控制策略实现及对比

Implementation and comparison of capacitor charge balance control strategies of DC excitation power generation system

全电/多电飞机技术以及军用车辆技术的发展对发电系统提出了高动态性能、低浪涌电压的要求。调磁式直流发电系统通过独立调节励磁维持输出电压稳定,系统输出动态性能取决于控制策略的好坏,传统电压比例积分控制难以兼顾系统动稳态性能。将电容电荷平衡控制方法用于提升直流发电系统动态性能,根据控制目标与控制方式的不同,分为经典电容电荷平衡控制(CBC)和基于电容电荷平衡控制原理的电压闭环最优比例积分控制(OPIC)策略以及电容储能闭环最优单比例控制(OSPC)策略。首先论述了经典电容电荷平衡控制原理,给出电压闭环最优比例积分控制策略以及电容储能闭环最优单比例控制策略的实现过程,并推导出外环系数整定方式。其次给出3种控制策略对比分析,指出经典CBC可实现系统最优瞬态回复过程,但切换过程存在二次调节现象需加以补偿。算法2与算法3通过动态切换外环系数实现系统最优控制,但由于内部励磁环跟踪滞后,只能逼近理想的电容电荷平衡控制效果。最后通过实验验证所提控制策略的正确性,结果表明所提控制策略相较于传统电压比例积分控制更有利于提升系统动态性能,其中,OPIC兼顾动稳态调节性能,OSPC抗负载扰动性好,经过补偿的CBC动态性能最佳。

The output voltage stability of the adjustable excitation DC power generation system is maintained by independently regulating the excitation.The output dynamic performance of the system depends on the quality of the control strategy.The traditional voltage Proportional Integral(PI) control is difficult to take into account the dynamic and steady-state performance of the system.In this paper,the capacitor Charge Balance Control(CBC) method is used to improve the dynamic performance of the DC power generation system.According to the different control objectives and control methods,we have classical CBC strategy,voltage closed-loop Optimal PI Control(OPIC) strategy based on the CBC principle,and capacitor energy storage closed-loop Optimal Single Proportional Control(OSPC) strategy.Firstly,the classical CBC principle is discussed,the realization process of OPIC and OSPC is given,and the outer loop coefficient setting method of OPIC and OSPC is derived based on the idea of CBC.Secondly,a comparative analysis of the three control strategies is given.It is pointed out that although the classical CBC can realize the optimal transient recovery process of the system,the secondary adjustment phenomenon in the switching process needs to be compensated.OPIC and OSPC realize the optimal control of the system by dynamically switching the outer loop coefficient;however,due to the tracking lag of the internal excitation loop,OPIC and OSPC can only approach the ideal CBC effect.Finally,the correctness of the proposed control strategy is verified by experiments,and the results show that the proposed control strategy is more beneficial to improve the dynamic performance of the system than the traditional voltage PI control.In addition,OPIC satisfies dynamic and steady-state regulation performance,OSPC has good anti-load disturbance,and the dynamic performance of compensated CBC is the best.