A New Control Method of VSC to Supporting Instantaneous Voltage at PCC Point

In recent years, the engineering practice shows that the VSC has obvious drawbacks when it is connected to weak grid. It is easy to cause insufficient voltage support at PCC point of power systems. In order to solve this problem, this paper proposed an instantaneous voltage control method by using the integral characteristic of filter capacitance, which is also based on the instantaneous current control method. Because there is only one low leakage reactance transformer between the external potential of VSC and the PCC point, the two are strongly connected, which can effectively control the voltage of PCC point. At first, this paper analyzed the principle of PCC instantaneous voltage control method. Then, the frequency response and stability of the proposed method are analyzed in the complex frequency domain. In the electromagnetic transient simulation software, the voltage support capacity and fault ride through ability of the proposed method is simulated and verified. Finally, this paper compared the proposed method proposed with the other existing method - the proposed method is simpler, more reliable, and more widely applicable and has strong voltage support capacity and fault ride through ability, which can provide key technical support for the construction of new power system dominated by new energy in the future.