The construction and maintenance cost of the large-scale renewable energy cluster through diode rectifier transmission system is low

which is an advantageous scheme for the development of ' Desert

Gobi

and Desertification Land ' renewable energy and offshore wind power. However

in the existing research

the converter station at the receiving end generally adopts the constant DC bus voltage control strategy of the flexible HVDC transmission system. During the transient processes of the voltage amplitude drop and short-circuit fault of the sending end power grid

it is easy to cause the power can easily fail to be sent out due to voltage imbalance

and the fault ride-through ability of the system is weak. Therefore

this paper deeply analyzes the transient characteristics of power transmission following the control strategy of fixed DC bus voltage

and reveals the blocking mechanism of the power transmission of diode rectifier station during the transient process. On this basis

a control strategy of receiving end converter station based on variable equivalent resistance is proposed

which keeps a proportional square relationship between the power and DC bus voltage in a short time scale. When the voltage drop occurs in the sending end AC system

the DC bus voltage of the receiving end converter station can respond to the change in time

and the diode rectifier station always maintains the power transmission state. When the fault is removed

the variable coefficient control is used to quickly restore the system to a stable state

so as to improve the fault ride-through ability of the system and ensure high steady-state transmission efficiency. The simulation results verify the effectiveness and feasibility of the proposed method.