MPPT control circuit based on improved H-bridge DC-DC topology

Abstract

The invention discloses an MPPT control circuit based on an improved H-bridge DC-DC topology, and belongs to the technical field of control of a solar unmanned aerial vehicle power supply system DC-DC circuit. The MPPT control circuit comprises a solar array working voltage sampling circuit, a solar array working current sampling circuit, a bus voltage sampling module, a bus current sampling module, an overvoltage protection module, a logic module, an MPPT mode driving module and a direct-through mode driving module. According to the MPPT control circuit, the working mode of the DC-DC circuit is automatically judged and selected, and two adjusting modes of Buck and Boost under the MPPT mode are enabled to be smoothly switched effectively through transition of the direct-through mode so as to guarantee the stability of the system. Unified control of the MPPT mode and the direct-through mode can be realized, the maximum output power point of a solar cell array can be tracked in real time, the utilization rate of the solar cell array can be enhanced and the power supply output capacity of an unmanned aerial vehicle power supply system can be enhanced so as to provide reference and help for energy supply of near space aircrafts represented by the solar unmanned aerial vehicle.

Description

technical field [0001] The invention belongs to the technical field of DC-DC circuit control of a solar unmanned aerial vehicle power supply system, and in particular relates to an MPPT control circuit based on an improved H-bridge DC-DC topology. Background technique [0002] As the core component of the solar drone, the main task of the solar drone power system is to provide high-quality, high-reliability continuous power supply for the drone during flight to meet the power demand of the whole machine power load. Compared with the previous space power system, the solar UAV power system has the characteristics of ultra-large scale, ultra-high power, and multi-energy integration. It not only needs to achieve high-power output, but also requires DC-DC circuits to The topological structure and its control strategy put forward higher requirements. [0003] Nowadays, in terms of control strategies, in view of the special flight environment and complex working conditions of sola...

AI Technical Summary

Problems solved by technology

Although the ordinary H-bridge topology uses advanced synchronous rectification technology to significantly improve the DC-DC conversion efficiency, there is a defect in the topology itself: at the moment when the Buck and Boost adjustment methods are switched, the switching tube’s The duty cycle will jump, which means that the output voltage will have a large pulsation when the adjustment mode is switched, which is not advisable from the perspective of system stability.

[0005] At present, the control circuit based solely on the H-bridge DC-DC topology has gradually matured, but it lacks a unified control method combined with the direct mode. The difficulty lies in the mutual conversion between Buck regulation, direct mode and Boost regulation.

In addition, in the field of solar UAV power system, it is also a technical bottleneck to apply the MPPT control strategy to the DC-DC circuit of the improved H-bridge topology

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