Abstract: In the HVDC wind power integration grid, rapid location and ride-through of AC faults is one of the main problems to be solved. This paper first analyzed the transient characteristics of AC faults at different locations and with different properties in the HVDC grid, and proposed a novel criterion of transient energy transfer index, i.e. power flow entropy. Based on the sensitivity of power flow transfer entropy to different AC faults, a method for off-site detecting and locating AC faults was proposed, and a source-side transient energy dissipation strategy was designed without long-distance communication. Furthermore, a method for discriminating permanent faults was proposed, and a coordinated control strategy of the wind farm and dissipation resistors was designed. Finally, the effectiveness of the proposed fault diagnosis and ride-through method was verified by PSCAD simulations. Under this method, the system can achieve uninterrupted operation in any transient or permanent AC fault in receiving terminals.