Excessive Heating of IGBTs and How to Avoid Them

An excessive or unexpected increase in the internal temperature can lead to the evaporation of water and loss of coolants in critical turbine cooling systems, and may eventually cause the turbine electronics to overheat. This is a particular concern on machines with an open-loop cooling system and can occur even with the use of high-quality refrigerants. An open-loop system allows water to gradually evaporate from the water-glycol refrigerant in the bipolar insulated gate transistor (IGBT) circuit, particularly during warm weather. (IGBTs are an electronic component typically used in turbines due to their fast and efficient switching capabilities. ) 

A problem can occur when the evaporation of water lowers the coolant level and raises the concentration of the mixture. If the system is left unchecked and not maintained, the resulting imbalance of the mixture inhibits the cooling properties of the fluid. This potentially compromises the IGBT. It goes without saying that a loss of IGBT components due to overheating can result in costly hardware losses and significant downtime of the turbine. To avoid this, wind operators have "bandaged" the problem with a regular rate of coolant monitoring, water replenishment and rebalancing of the coolant mixture. This approach may work when diligently respected, but it is an expensive maintenance plan.