The thermal solution mainly depends on the inverter power
With the reduction of the overall size of photovoltaic inverter and the increase of the single machine power, the requirements for thermal design are becoming higher and higher. The designer must comprehensively consider the cooling effect, protection, installability, maintainability and economic cost of the inverter cooling system. Among them, the single machine power is an important basis for designing the cooling solution.
The inverter cooling technology includes natural cooling, forced air cooling, liquid cooling and phase change cooling. The research shows that the cooling efficiency of forced air cooling is 10-20 times that of natural cooling, and liquid cooling is also a more efficient heat dissipation method. From the point of view of the complexity of the structure and the difficulty of implementation, the forced air cooling system is simpler, easier to implement and more reliable than the liquid cooling system. Therefore, forced air cooling is preferred in the power supply industry, followed by natural cooling, liquid cooling and other cooling methods.
When the power is less than 20kW, natural cooling can achieve the optimal matching of product volume, weight and comprehensive performance; When the power is greater than 25kW, the heat flow density of heat dissipation is larger, and forced air cooling is a more economical and efficient practical means; When the power is between 20kW and 25kW, the comprehensive cost performance of natural cooling and forced air cooling is equivalent. For large wind energy converters with power of several million W, the first choice cooling mode is liquid cooling.
The string photovoltaic inverter generally operates in the outdoor environment above 70 ℃, and the system heat dissipation in the high-temperature environment has a particularly important impact on the performance and life of the product The heat dissipation technology includes natural cooling, forced air cooling, liquid cooling, phase change cooling and other forms, which are mainly selected according to the power of the inverter.
