The improvement of real-time dynamic phasor simulation to transient process of LCC-HVDC transmission system

In order to realize the coordination of relay protection in High Voltage AC/DC hybrid system, it is critical to quantify and summarize the characteristic of fault current form DC inverter side in real-time, therefore, our article proposed high accuracy, generic voltage switching function and current switching function in the form of dynamic phasor, which are able to describe unsymmetrical switching operations and commutation failures. A multi-fault scenes tests were conducted against mature electromagnetic transient simulation software PSCAD to verify the computation time and accuracy of our modified real-time Dynamic Phasor Modelling (DPM), which show promising results that our model can be easily implemented in online commutation failure forecasting, online power system protection setting or speed-up simulation considering commutation failures.