基于最大点功率跟踪的两阶段光伏逆变器设计

Design of Two-stage Multifunctional Photovoltaic Inverter Based on Maximum Power Point Tracking

提出了一种两阶段多功能光伏逆变器(QMFI),有功功率借助于该结构可以在一个功率转换器内从光伏阵列直接传输到电网或负载,从而提高转换效率。此外,考虑QMFI最大功率点跟踪(MPPT)的实现和非有功电流的补偿,提出了QMFI的数学模型,从而获得有效的控制参数。在求解过程中,采用基于旋转坐标系的分析模型,并推导了QMFI的空间矢量脉冲宽度调制策略,直观地揭示了非有功电流补偿对两阶段有功潮流的影响。最后,通过3 kVA样机验证了所提方案的可行性和有效性。

In recent years,the application of distributed photovoltaic power generation becomes more and more widely,the corresponding inverter technology requirements are also increasing.In order to solve this problem,a two-stage multifunctional photovoltaic inverter(QMFI)is proposed in this paper.The active power can be directly transmitted from the photovoltaic array to the grid or load in a power converter,so as to improve the conversion efficiency.In addition,the realization of maximum power point tracking(MPPT)of QMFI and the compensation of non-active current are considered in this paper.Amathematical model of QMFI is proposed to obtain effective control parameters.In the process of solving the problem,the paper adopts the analytical model based on rotating coordinate system,and deduces the space vector pulse width modulation strategy of QMFI,which intuitively reveals the influence of non-active current compensation on the two-stage active power flow.Finally,the feasibility and effectiveness of the proposed scheme are verified by 3 kVA prototype.