Three-phase cascaded multi-level photovoltaic grid-connected inverter control system

Abstract

The invention discloses a three-phase cascaded multi-level photovoltaic grid-connected inverter control system, which includes a main controller, an optical fiber communication unit, multiple sub-controllers, a driver one, a driver two, a zero-crossing comparator, a voltage Transformer; the main controller is connected to each sub-controller through an optical fiber communication unit, and the sub-controller is used to drive the signal of the DC-DC module to be directly connected to the driver two, and the sub-controller is used to drive the signal of the DC-AC module and the zero-crossing The output signals of the comparators are multiplied and then connected to driver one. The invention has simple structure and convenient operation, and can realize independent control of each DC-DC module and DC-AC module of the three-phase cascaded multi-level photovoltaic grid-connected inverter, and the different modules of the same phase do not affect each other. The three-phase inverter is completely independently controlled, which improves the reliability and stability of the circuit. The controlled three-phase cascaded multi-level inverter has a high DC voltage utilization rate, a low switching frequency of the switching tube, and a high system energy utilization rate.

Description

Technical field [0001] The invention relates to the field of photovoltaic inverter power generation equipment, in particular to a three-phase cascaded multi-level photovoltaic grid-connected inverter control system specially used in photovoltaic power stations. Background technique [0002] With the development of human society, energy consumption is increasing, and the world's fossil energy will reach its limit one day. At the same time, due to the massive burning of fossil energy, the global ecological environment is deteriorating day by day, posing a great threat to human survival and development. In this context, solar energy, as a huge amount of renewable energy, has attracted people's attention, and governments of various countries are gradually promoting the development of solar photovoltaic power generation industry. [0003] As a topological structure of high-voltage and high-power converters, cascaded multi-level inverters have received close attention from expert...

AI Technical Summary

Problems solved by technology

However, the realization of cascaded multilevel inverters depends to a greater extent on the design of the control system and the choice of control methods. The more cascaded units, the more complex the control system.

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