用于太阳能光伏并网发电的五电平逆变器

Five-level inverter for solar photovoltaic grid-connected power generation

为更好地实现太阳能光伏并网发电,在二电平太阳能光伏并网发电逆变器基础上,通过改进DC-DC变换器结构,采用按低次谐波含量最少原则产生阶梯波的调制策略,设计一种新型五电平逆变器.应用Simulink对新型五电平逆变器单相系统模型进行仿真,结果表明:在输出电平相同的情况下,新型五电平逆变器比二电平逆变器的输出电压谐波含量明显降低、逆变效率得到提高,适用于低压输入、高压大功率输出的太阳能光伏并网发电.

In order to realize solar photovohaic grid-connected power generation better, on the basis of two-level inverter for solar photovohaic grid power generation, and by improving the structure of DC-DC transformer and adopting the modulation strategy to produce step wave with minimum low order harmonic quantity, a new-type of five-level inverter is devised. Simulink is used to simulate the single-phase sys- tem model of the new-type of five-level inverter. The result shows that the output voltage harmonic content of the new-type of five-level inverter is cut obviously under the same output level and the inverting efficiency increases as compared to two-level inverters. And the new-type of five-level inverter is suitable to solar photovohaic grid-connected power generation with low voltage input and high voltage high-power out-put.