公开(公告)号：US20230261479A1

公开(公告)日：2023-08-17

申请号：US18167937

申请日：2023-02-13

Applicant: Danfoss Power Electronics A/S

Inventor： Oskari Leppäaho ,  Orges Gjini

IPC: H02J7/00 ,  H02M1/08

CPC classification number: H02J7/0016 ,  H02M1/08

Abstract: A voltage balancing circuit for capacitor banks or voltage cells connected in series. The circuit includes a DC-link with at least two capacitors or voltage cells connected in series and at least two emitter follower balancing circuits connected in parallel. At least one emitter resistor is provided between the emitter of each emitter follower balancing circuit and the mid-point of the DC-link. The gate emitter voltage applied to each emitter follower balancing circuit may be equal to its common gate voltage minus the voltage drop on the corresponding emitter resistor. The invention is also directed at a variable frequency drive for driving an electric motor or a power converter, having a corresponding voltage balancing circuit.