The present invention relates to an integrated control system of modular multilevel converter and method, through the detection of modular multilevel converter of upper and lower bridge arm of each sub module capacitor voltage, the upper and lower bridge arm current, and the AC power supply voltage, after a general controller operation processing after the upper and lower bridge arm PWM public duty ratio; the upper and lower bridge arm of each sub module capacitor voltage and the upper and lower bridge arm PWM public duty ratio after the upper and lower bridge arm controller processing, get the upper and lower bridge arm of each sub module of the PWM duty cycle; the sub module PWM for PWM control signal the empty sub module than through PWM signal generator, current, voltage converter sub module capacitor voltage balance control and converter control. The invention does not need to use the special charging and discharging power circuit of the capacitor; the utility model is suitable for various PWM modes; the utility model can flexibly control the circulating current and meet the special needs; the physical meaning is clear, and the theoretical basis is sufficient.
【技术实现步骤摘要】
本专利技术涉及,属于多电平电力电子功率变换器的控制
技术介绍
模块化多电平变换器拓扑采用级联式、模块化构造, 无需功率器件直接串联便可得到多电平的阶梯电压,具有较低的dU/dt和较低的电压谐波含量,在中/高压大容量系统中具有广阔的应用前景。该变换器拓扑结构如附图说明图1所示,图中,上桥臂和下桥臂各有N个子模块级联而成,各子模块为半桥结构,子模块直流侧并联有相同的电容器。由于模块化多电平变换器的各子模块直流侧电容处于悬浮状态,运行时各子模块电容会出现充放电差异, 因此会导致电容电压的不平衡问题。电容电压不平衡会直接威胁变换器的安全运行,因此该问题能否有效解决是模块化多电平变换器安全、可靠运行的关键。在《中国电机工程学报》2004年第24卷第4期145-150页刊登的“基于链式逆变器的50MVA静止同步补偿器的直流电压平衡控制”一文(作者刘文华等)对级联式静止同步补偿器的直流侧子模块电容平衡控制方法进行了研究,提出了采用在各子模块直流侧外加专用功率电路,通过控制直流侧电容器的充放电来实现电容电压平衡控制。但该方法需要额外增加外部复杂的专用功率电路,成本高、 ...
【技术保护点】
1.一种模块化多电平变换器的综合控制方法,其特征是,通过检测模块化多电平变换器上、下桥臂各子模块电容电压,上、下桥臂电流,以及交流侧电源电压,经过一个总控制器运算处理后得到上、下桥臂PWM公共占空比;上、下桥臂各子模块电容电压与上述上、下桥臂PWM公共占空比经过上、下桥臂控制器运算处理,得到上、下桥臂各子模块的PWM占空比;各子模块的PWM占空比经过PWM信号发生器产生各子模块的PWM控制信号,实现各子模块电容电压平衡控制和变换器的电流、电压控制。
【技术特征摘要】
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