Patent ID: 8254150
Filing Date: 2012-08-28
Classification: H02M

Abstract:
1. An inverter for providing alternating current to a load including a welding circuit, the inverter comprising: at least one commutation circuit configured to: receive power from a DC power source, during a storage phase of a cyclic procedure receive energy from inductive elements in the load, and during a feedback phase of the cyclic procedure control energy feedback to the load; each of the at least one commutation circuit comprising a recovery capacitor and energy-flow control means configured to control energy storage in and energy take-out from the recovery capacitor; and a bridge circuit connected to the commutation circuit, the bridge circuit being configured to deliver the alternating current to the load, the bridge circuit being connected to a bus forwarding power from the DC power source, and the bus being galvanically connected to the load, wherein the at least one commutation circuit is a two-pole having a first pole connected to a first node and a second pole connected to a second node; and the at least one commutation circuit is arranged to receive energy from the load and feedback energy to the load via the first and second nodes either directly or via the bridge circuit, wherein the energy-flow control means are arranged in a switching module comprising: a first flow control means configured to allow energy to be stored in the recovery capacitor, and a second flow control means configured to cause energy stored in the recovery capacitor to be fed into the load, the switching module being connected in series with the recovery capacitor the first flow control means being connected in parallel with the second flow control means, and the second flow control means being controllable in response to a control signal designating an amount of energy to be taken out of the recovery capacitor in a subsequent phase of the cyclic procedure.