Novel control method of single-stage three-phase photovoltaic grid-connected system

Abstract

Disclosed is a novel control method of a single-stage three-phase photovoltaic grid-connected system. Firstly, a digital signal processor (DSP) is used for performing photovoltaic array maximum power point tracking and voltage outer loop controlling, and by means of a series peripheral interface (SPI), the DPS communicates a first field programmable gate array (FPGA) processor, a second FPGA processor and a third FPGA processor to transmit an A phase given current signal iaref, a B phase given current signal ibref and a C phase given current signal icref respectively; then, the first FPGA processor is used for performing A phase current inner loop controlling and sine pulse width modulation and then transmitting driving signals to an A phase upper bridge arm and an A phase lower bridge arm of a photovoltaic grid-connected inverter; the second FPGA processor is used for performing B phase current inner loop controlling and sine pulse width modulation and then transmitting driving signals to a B phase upper bridge arm and a B phase lower bridge arm of the photovoltaic grid-connected inverter; and the third FPGA processor is used for performing C phase current inner loop controlling and sine pulse width modulation and then transmitting driving signals to a C phase upper bridge arm and a C phase lower bridge arm of the photovoltaic grid-connected inverter. The novel control method has the advantages of being high in reliability, highly modular and capable of independently adjusting each phase of currents.

Description

technical field [0001] The invention relates to a novel control method of a single-stage three-phase photovoltaic grid-connected system, which belongs to the application field of photovoltaic power generation system control technology. Background technique [0002] At present, in the field of photovoltaic grid-connected power generation, the control system is mainly designed based on the DSP chip. Since the DSP chip is based on software programming to complete the corresponding control functions, once the peripheral circuit structure that cooperates with the DSP chip becomes complicated, due to software interruption The uncertainty of occurrence may cause a certain delay to logic signals, such as square wave signals, leading to an increase in the probability of program failure. Field programmable gate array FPGA, which is more and more widely used in various control systems, can flexibly configure its internal specific logic circuit functions according to actual control need...

AI Technical Summary

Problems solved by technology

[0002] At present, in the field of photovoltaic grid-connected power generation, the control system is mainly designed based on the DSP chip. Since the DSP chip is based on software programming to complete the corresponding control functions, once the peripheral circuit structure that cooperates with the DSP chip becomes complicated, due to software interruption The uncertainty of occurrence may cause a certain delay to logic signals, such as square wave signals, resulting in an increase in the probability of program failures

Images