电流源型脉宽调制(Pulse width modulation,PWM)整流器因其网侧存在LC滤波器,系统的控制难度增加。传统直接功率控制策略下的整流器功率波形存在脉动,因模型预测控制具有卓越的动态特性以及直观的控制规律,采用模型预测直接功率控制(Mod...电流源型脉宽调制(Pulse width modulation,PWM)整流器因其网侧存在LC滤波器,系统的控制难度增加。传统直接功率控制策略下的整流器功率波形存在脉动,因模型预测控制具有卓越的动态特性以及直观的控制规律,采用模型预测直接功率控制(Model predictive direct power control,MPDPC)对传统控制策略进行改进。首先建立了三相PWM整流器的数学模型,给出了每个采样周期内的功率变化率,并推导出相邻采样周期之间的功率关系,然后给出基于单矢量的模型预测直接功率控制策略,提出了基于双矢量的模型预测直接功率控制策略,并优选出两个电流矢量,计算在一个采样周期内的作用时间,并对其进行修正。最后,在Matlab/Simulink仿真软件验证了所提控制策略的可行性和有效性。展开更多
We propose a new power conversion system for a permanent magnet synchronous generator(PMSG) based grid-connected wind energy conversion system(WECS) operating with fully-controlled back-to-back current-source converte...We propose a new power conversion system for a permanent magnet synchronous generator(PMSG) based grid-connected wind energy conversion system(WECS) operating with fully-controlled back-to-back current-source converters. On the generator side, two independent current-source rectifiers(CSRs) with space-vector pulse width modulation(SVPWM) are employed to regulate and stabilize DC-link currents. Between DC-link and the electrical grid, a direct-type three-phase five-level current-source inverter(CSI) is inserted as a buffer to regulate real and reactive power fed to the grid and thus adjusts the grid side power-factor. We also present a current-based maximum power point tracking(MPPT) scheme, which helps the generator extract the maximum power through closed-loop regulation of the generator speed. By applying the multilevel modulation and control strategies to the grid-side five-level CSI, a multilevel output current waveform with less distortion is produced, and the bulk requirement of the output capacitor filter to eliminate the harmonic current is reduced. All the proposed concepts are verified by simulation models built in a PSIM environment.展开更多
文摘电流源型脉宽调制(Pulse width modulation,PWM)整流器因其网侧存在LC滤波器,系统的控制难度增加。传统直接功率控制策略下的整流器功率波形存在脉动,因模型预测控制具有卓越的动态特性以及直观的控制规律,采用模型预测直接功率控制(Model predictive direct power control,MPDPC)对传统控制策略进行改进。首先建立了三相PWM整流器的数学模型,给出了每个采样周期内的功率变化率,并推导出相邻采样周期之间的功率关系,然后给出基于单矢量的模型预测直接功率控制策略,提出了基于双矢量的模型预测直接功率控制策略,并优选出两个电流矢量,计算在一个采样周期内的作用时间,并对其进行修正。最后,在Matlab/Simulink仿真软件验证了所提控制策略的可行性和有效性。
基金Project supported by the National Natural Science Foundation of China(No.51277164)the Natural Science Foundation of Zhejiang Province,China(No.Y1111002)
文摘We propose a new power conversion system for a permanent magnet synchronous generator(PMSG) based grid-connected wind energy conversion system(WECS) operating with fully-controlled back-to-back current-source converters. On the generator side, two independent current-source rectifiers(CSRs) with space-vector pulse width modulation(SVPWM) are employed to regulate and stabilize DC-link currents. Between DC-link and the electrical grid, a direct-type three-phase five-level current-source inverter(CSI) is inserted as a buffer to regulate real and reactive power fed to the grid and thus adjusts the grid side power-factor. We also present a current-based maximum power point tracking(MPPT) scheme, which helps the generator extract the maximum power through closed-loop regulation of the generator speed. By applying the multilevel modulation and control strategies to the grid-side five-level CSI, a multilevel output current waveform with less distortion is produced, and the bulk requirement of the output capacitor filter to eliminate the harmonic current is reduced. All the proposed concepts are verified by simulation models built in a PSIM environment.
