A photovoltaic power generation system mppt disturbance method

Abstract

The invention relates to an MPPT perturbation method for a photovoltaic power generation system. The photovoltaic power generation system includes N front-stage topologies and a rear-stage topology. The input ends of the front-stage topologies are respectively connected to photovoltaic modules. The N front-stage topologies The output terminal of the output terminal is connected in parallel to the input terminal of the subsequent stage topology, and it is characterized in that, the MPPT perturbation method includes the first sub-period and the second sub-period of the MPPT perturbation cycle, in the first sub-period, the previous stage topology perturbation is obtained After the input power P1 of the previous stage is disturbed by MPPT, and the stable input power P2 after the topological disturbance of the latter stage is obtained, in the second sub-period, the input power P3 before the topological disturbance of the previous stage is obtained, and then the MPPT disturbance of the previous stage is performed, and the previous stage MPPT disturbance is obtained. Stable input power P4 after stage topology disturbance. In the present invention, the MPPT disturbance is performed on the front and back stages respectively, so that the system has a wide MPPT range, and information interaction between the front and back stages is not required.

Description

technical field [0001] The invention relates to the field of photovoltaic power generation, in particular to an MPPT disturbance method for a photovoltaic power generation system. Background technique [0002] At present, photovoltaic controllers and photovoltaic inverters are mostly one-level or two-level topology systems, and the two-level topology can realize multi-channel MPPT and has a wider MPPT range. [0003] Photovoltaic two-stage MPPT system such as figure 1 As shown, multiple front-stage topologies converge to the rear stage, and are output by the latter stage. The photovoltaic power generation system composed of two-stage topology generally uses the front-stage topology to perform MPPT tracking, and the latter-stage topology to stabilize the input power of the busbar. [0004] In the prior art, there are generally two ways to control the reference value of the bus voltage: [0005] 1. Set a fixed bus reference value according to requirements. [0006] 2. Calc...

AI Technical Summary

Problems solved by technology

The spatial distance between the front and rear topologies is relatively long, and due to factors such as line interference, information exchange becomes difficult and the overall system reliability decreases

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