Compact dimensions and reduced system costs are design goals, which developers in power electronic designs always pursue. Now, because of the ever-growing amount of energy consumed by home appliances, engineers working on such applications have an additional goal: maintaining a high power factor (PF). Especially air conditioners, with power ratings of 1.8 kW or more, are amongst the power-hungriest devices. Here, a power factor correction (PFC) is mandatory and for PFC, designers regard IGBTs (Insulated Gate Bipolar Transistors) as being the most appropriate switching devices in terms of cost-performance ratio.
In PFC systems, a lower switching frequency increases the size of the boost inductor. As a result, developers cannot place it on the main circuit board. In this case, the price of the inductor is inevitably high, and the form factor of the system is limited, rendering the other design goals nearly impossible. Additionally, the likelihood of a short circuit (SC) event occurring during installation or maintenance tends to favor the selection of an IGBT with a SC withstand capability for protection.
To ensure short-circuit capability, the Vce(sat) and switching performance of the device are reduced, and the device will be less performant. Consequently, the demand for integrating the PFC inductor on the main board by increasing the switching frequency continues to rise. Doing so will minimize the system‘s form factor and weight, reduces the cost of the inductor, and enables the use of high-performance IGBTs.