Method for calculating working temperature of component IGBT of photovoltaic inverter

Abstract

The invention discloses a method for calculating a working temperature of a component IGBT of a photovoltaic inverter. Based on an energy conservation law, a mathematic relational formula of an external environment temperature, input power and IGBT loss and temperature rise is established through a loop iteration method by adopting a heat transfer principle and junction temperature and heat resistance principles; and calculation is performed by utilizing a loop iteration function in EXCEL to obtain shell temperatures and junction temperatures of the high-power component of the inverter under different environment temperatures and different input power. The errors between the predicted working temperatures of the IGBT under the different environment temperatures and the different input power, and the actually measured temperatures are within + / -8%; the method is used for predicting the working temperatures of the high-power component of the photovoltaic inverter under high and low-temperature environments and high and low-load ratios; and a theoretical basis is provided for assessing the reliability of the inverter.

Description

technical field [0001] The invention relates to a method for calculating the operating temperature of a photovoltaic inverter component IGBT, and belongs to the technical field of photovoltaic inverter reliability. Background technique [0002] As the core equipment of the photovoltaic power generation system, the inverter plays a decisive role in the power generation that is finally connected to the grid, and the data shows that the failure rate of the inverter in the large-scale photovoltaic power station is 40.29×10 -6 / h (compared to photovoltaic modules 0.0152×10 -6 / h), ranking first among the components of the photovoltaic system, the inverter is both the key link and the weak link of the entire photovoltaic power generation system. The main factors affecting the reliability of the inverter are heat and temperature rise. [0003] Perpina X. et al. analyzed the effect of uneven temperature distribution inside the insulated gate bipolar transistor (IGBT) power module ...

AI Technical Summary

Problems solved by technology

Abroad has done a lot of research on the reliability of inverters, but there is no specific analysis of the impact on temperature rise under different external conditions

[0004] During the actual operation of the photovoltaic system, the temperature of the components in the photovoltaic inverter may be too high, resulting in a decrease in the conversion efficiency of the inverter or a direct failure, which poses a threat to the safety and reliability of the photovoltaic system.

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