Start-up control method of photovoltaic inverter and photovoltaic inverter system

Abstract

This application relates to a start-up control method of a photovoltaic inverter and a photovoltaic inverter system. By monitoring the numerical value of the output voltage of a photovoltaic module, it is possible to effectively find not only the most basic start-up conditions for the inverter circuit, but also the The output voltage of the photovoltaic module that makes the DC / DC converter switch to boost mode. By monitoring the time it takes for the voltage value of the DC bus to change from the first preset voltage value to the second preset voltage value, and during this period of time, it is less than the minimum output power of the photovoltaic module to charge the DC bus to make the DC bus voltage change from the first to the second preset voltage. Under the condition of the time it takes for a preset voltage value to change to a second preset voltage value, the control relay is self-checked and closed, and the DC / AC converter is started, thereby starting the entire photovoltaic inverter. This start-up control method does not require external hardware support, not only can make the inverter circuit of the photovoltaic inverter run stably, but also the relay will not repeatedly self-check, there is no noise during the start-up process, and there is no energy waste.

Description

technical field [0001] The present application relates to the technical field of photovoltaic inverters, in particular to a photovoltaic inverter start-up control method and a photovoltaic inverter system with a photovoltaic inverter start-up control function. Background technique [0002] For conventional photovoltaic inverters, during the start-up process, the photovoltaic modules are generally allowed to charge the DC bus first. After the voltage value of the DC bus reaches the preset voltage value, the detection of the relay is carried out, and then the relay is closed to complete the start-up of the photovoltaic inverter. [0003] However, in this process, if the output power of the photovoltaic module is insufficient, the voltage value of the DC bus will drop too much during the self-test process of the relay, and the controller will determine that the photovoltaic inverter is working abnormally, thus interrupting The start-up process of the PV inverter. Therefore, i...

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Problems solved by technology

[0007] Based on this, it is necessary to solve the problem that the start-up control method of the traditional photovoltaic inverter cannot accurately find the start-up timing that can make the photovoltaic inverter circuit run stably, the relay will not repeatedly pull on and off, and will not waste excess energy. Provide a start-up control method for a photovoltaic inverter and a photovoltaic inverter system with a start-up control function for a photovoltaic inverter

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