General   
Loval power electronics resistors are specially designed for thyristor protection of RC-circuits. Their main feature is the ability to withstand high voltages and high temperatures.

The number of resistors is chosen according to the required power and cooling conditions. Resistors are mounted on an air or water cooled heat sink. Typical application is frequency converters.

Challenges

• High voltage
• High surface current
• High temperature
• Limited space
• Glow discharge
• Installation and operation
• Official requirements

Solutions
Resistor elements are constructed with materials that correspond to the above challenges. The inorganic materials used in the hot parts prevent glow discharge and surface currents.

Even though the core temperature is high, the materials are able to withstand these temperatures. With water cooled heat sink, the heat load to the environment remains small. Typical test voltage of the resistors is 5000 V.