Power semiconductors play a key role to produce energy from renewable sources. In wind turbines, power semiconductors are used to convert power and to couple the generator with the grid. They are also built into various auxiliary drives such as yaw drives, pitch drives, pumps and into protection circuits like crowbars.
Wind power converters control a number of vital functions and applications and therefore require power semiconductors of the highest quality standards. This applies in particular to offshore wind converters which operate in exceptionally harsh environments exposed to salt, humidity etc. Rapid growth is projected for the offshore segment.
Wind energy turbines must also be designed to deliver maximum levels of availability in order to contribute to grid stability. This applies not only to the converter, but also to the various auxiliary drives mounted in different positions. Grid stability therefore depends on power semiconductor assemblies offering dynamic capabilities, outstanding functionality and superior reliability.
Fixed-speed designs are suited to generators up to 400 kW. New designs are usually based on semiconductor solutions to fulfill grid code requirements. Nevertheless, Infineon delivers the full range of grid coupling components, with thyristors and other bipolar semiconductors available as modules, discs and stacks.
An EE generator feeds the inverter via a bipolar rectifier, with the generator voltage controlled by excitation. The grid inverter is controlled by an IGBT as the effect of excitation. This design is an established solution already successfully deployed in modern systems.
Crowbars, choppers and active filters are important elements in wind turbine designs. Even though these components are not actively involved in feeding energy, they are needed to manage external impacts and fulfill grid stability requirements.