Patent ID: 8036009
Filing Date: 2011-10-11
Classification: H02M

Abstract:
1. A method for supplying energy to and discharging energy from a resistive-inductive load or pure inductance, which is used to produce a magnetic field, comprising: supplying electrical power to the resistive-inductive load or pure inductance for excitation and de-excitation at a relatively high voltage in order to reduce thermal losses; using a rectifier with a low power loss and converter valves to commutate current and to feed the resistive-inductive load or pure inductance; using the rectifier and a transformer to transform voltage, the transformer having primary and secondary sides; actuating the converter valves to reduce commutation losses on the secondary side of the transformer, wherein a freewheeling circuit accepts the current after the rectifier and the transformer are switched off, and the current is commutated into the freewheeling circuit in line with commutation between different rectifier paths.