一种改进的高增益无电压尖峰分裂Y源逆变器

Improved High-gain Split Y-source Inverter Without Voltage Spikes

在分布式可再生能源发电系统中,Y源逆变器YSI(Y-source inverter)拓扑已被应用于实现灵活地升降压。然而在系统需要高电压增益时,Y源逆变器的调制因数和升压占空比相互制约的缺陷导致其电压质量和直流母线利用率大大降低。此外,在考虑漏感的影响时,YSI会产生由感应电流突变引起的电压尖峰。鉴于此,提出一种改进型分裂Y源逆变器ISYSI(improved split Y-source inverter),通过把分裂源结构与Y源阻抗网络相结合并且加入电压钳位单元,不仅能有效解决上述问题,还可以显著提高系统电压增益,同时消除二极管寄生电容和Y源阻抗网络漏电感谐振引起的电压振荡。对ISYSI进行详细的理论分析,仿真与实验结果验证了该逆变器的可行性。

In power generation systems based on distributed renewable energy,the topology of a Y-source inverter(YSI)has been applied to realize a flexible buck-boost function.However,the mutually constrained disadvantage of the modulation factor and boost duty cycle of the YSI leads to a significant reduction in voltage quality and DC bus utilization when a high voltage gain is required by the system.In addition,when considering the effect of leakage inductance,the YSI will generate voltage spikes caused by sudden changes in the induced current.In view of these problems,an improved split Y-source inverter(ISYSI)is proposed.By combining a split-source structure with a Y-source impedance network and incorporating a voltage clamp unit,the above-mentioned problems are solved effectively,and the system’s voltage gain is significantly improved while eliminating the voltage oscillations caused by the resonance of the diode parasitic capacitance and the leakage inductance of the Y-source impedance network.A detailed theoretical analysis of ISYSI is carried out,and the corresponding simulation and experimental results are provided to verify the feasibility of the proposed inverter.