摘要
三相电压型光伏并网逆变器,直接控制其三相电流较困难。同步旋转坐标下基于PWM技术的PI控制方法动态响应快,且可实现对指令的无静差跟踪,但是d、q两相直流电流之间还存在耦合关系,不利于控制设计,同时还存在电网电压的影响,为了消除这些影响,运用了前馈解耦控制算法,结合空间矢量SVPWM给出了逆变器的电流控制策略。浮点数字信号处理器TMS320F28335精度更高、运算速度快、具有丰富的外设资源,运用该处理芯片设计了逆变器的数字控制系统,包括硬件和软件的设计。进行了M atlab/S imu link环境下的系统建模与仿真;完成了样机研制。结果表明优化的设计算法加上高性能的处理芯片,设计出的大功率逆变器能够实现高功率因数并网,电流谐波含量低,控制系统稳定可靠、控制精度高,具有很好的性能,达到了预期的设计要求。
It is difficult to directly control the three-phase current of three-phase voltage photovoltaic inverter.PI control based on PWM under synchronous rotating reference frame,will yield quick dynamic response,and track command without static error.But the inter-coupling between d,q two phase currents and the effect of the grid voltage,will make the design of PI controller more difficult.Therefore,to tackle with such difficulty,a feed forward decoupling control algorithm with SVPWM is applied to form a current control strategy for inverter.Floating-point digital signal processor TMS320F28335 with higher precision and computing speed has rich peripheral resources.The hardware and software of the control system which is based on this chip was designed.System modeling and simulation under Matlab/Simulink and experimental prototype are all worked out.The result has shown that the inverter with the optimal design algorithm and high-performance processing chip not only has a performance with higher power factor grid-connecting,lower harmonic current component,but also with a good stability and high control precision to achieve the desired design requirements.
出处
《电子器件》
CAS
2011年第3期273-277,共5页
Chinese Journal of Electron Devices
