Hybrid HVAC-HVDC transmission line is an efficient way to enhance the transport of bulk electric power from the corridor.However

due to the existence of adjacent AC transmission line

the DC line surface electric field will be superimposed with AC component.Since the characteristics of corona discharge is directly determined by the intensity of electric field

the superimposed AC component will inevitably change the characteristics of corona current pulses from the DC transmission line.Hence

the radio interference caused by the DC transmission line will be distorted.The quasi-peak response of electron-magnetic interference（EMI） receivers is generally used to characterize the radio interference.In this paper

a numerical method was presented to simulate the quasi-peak response in time domain.The validity of the method was verified by comparing with CISPR specifications as well as with the measured results of an EMI receiver.The quasi-peak response of EMI receiver to positive corona current pulses that were adjacent to AC transmission lines was analyzed.The result shows that the radio interference from DC conductors that are adjacent to AC conductors mainly depends on the mean repetition frequency and the amplitude of the corona current pulses

the effect of distribution pattern of corona current pulses can be ignored.The quasi-peak response is proportional to the amplitude of the corona pulses

and increases with the repetition frequency in gradually slow manner.The results can provide useful references for the radio interference problem from hybrid AC-DC transmission lines.