When power failures become a problem

In many areas, modern technical installations need to function smoothly at all times, even in the event of line disturbances – from voltage drops to blackouts. Datacentres, intensive care units, building security and control systems in particular need a constant energy supply to prevent malfunction or system failures. In these situations, any power failure could impact important processes, lead to data losses or even endanger lives.

Systems for temporary storage of electric energy

To be able to integrate renewable energy sources which are not continuously available into the  grid energy supply, high-performance energy storage is essential, otherwise the stability of the power supply is at risk. The most widely used storage today is that based on accumulators of which the network connection is controlled by the power semiconductors.

Reliable protection with UPS systems

To prevent potential power failures to impact on sensitive areas such as those mentioned above, systems for ensuring uninterrupted power supply (UPS) are increasingly being installed. In the event of a blackout, these systems supply energy from a battery bank to the connected loads. The storage batteries are charged by rectifying mains voltage; in the event of a blackout, the UPS system has to generate AC voltage from the DC voltage.

Using active line filters to limit mains disturbance

The switching pulses of the power semiconductors in the power converters cause harmonics in the electric supply line. In order to comply with the energy suppliers' strict specifications for guaranteeing the high quality of the mains voltage, active line filters are used to compensate for highly dynamic reactive power, harmonics and flickers.

Power semiconductors for a growth market

SEMIKRON makes around 11 per cent of its turnover from power modules for UPS systems and active filters. In view of the increasing consequences of an unstable power supply, this market is a growth market. In 2012, the renowned market research institution, IMS Research, predicted that investments in new datacentre infrastructure in regions such as China, India, Russia and Eastern Europe would be an important driver for growth in the UPS market until 2016.

Demanding requirements

UPS systems face demanding requirements. They must be robust and reliable, and guarantee the best possible line quality. A push for higher energy efficiency at reduced cost rounds off the profile. As a result, 3-level topologies have become increasingly common in the market for uninterrupted power supplies. Special IGBT modules enable UPS systems to be manufactured, representing a milestone both in terms of their energy efficiency and in terms of reliability and costs.

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