Composite DC power transmission equipment

The invention provides composite DC power transmission equipment. The equipment comprises a fault isolation unit including a plurality of first power electronic switch units connected in series, a flow control unit which is connected to the fault isolation unit and is used for controlling the flow distribution between converter stations, and a control unit which is connected to the fault isolationunit and the flow control unit and is used for controlling the flow control unit and the fault isolation unit to execute preset action, wherein each of the first power electronic switch units comprises a first switch branch and a first capacitor, the first switch branch comprises at least two power electronic switches connected in series, and the first capacitor is connected at two ends of the first switch branch in parallel. Through mutually connected DC isolation unit, flow control unit and control unit, the fault isolation of DC power transmission is achieved, compared with a scheme of using a unified power flow c