New switching technologies in medium-voltage systems-application and requirements

Deregulation is setting new standards also in the energy market. It is creating new opportunities for power supply corporations and industrial suppliers. The direct competition in power distribution exerts severe cost pressure on the system operation with the result that systems are expanded only if absolutely necessary. Consequently, the quality of power supply is stagnating or even, deteriorating. To be able to act more flexibly and cost-effective and to meet the requirements of the changed market the operators of public distribution systems and industrial networks ask for new switching solutions. These solutions include fast acting solid state circuit-breakers and also DC. transmission systems based on electronic power modules and superconducting fault current limiters, and can be used, for example, to link different system sections flexibly without impairing stability or short-circuit behavior.