Practical Calculation for Short Circuit Current in Power System without Synchronous Generator Source

With the construction and development of new type of power system in China, the penetration rate of renewable energy is increasing year by year. With the continuous increase in installed capacity of renewable energy, the sending end networks, such as the Shagehuang Wind and Photovoltaic Base and the Southeastern Tibet Clean Energy Base, have no synchronous generator power supply and have only power electronic power supply. The existing methods for short circuit current calculation are mainly applicable to systems with synchronous generators as the primary or only source. So there is an urgent need to conduct research. This article aims to efficiently and accurately calculate the initial effective value of short circuit current in power systems without synchronous generator source. It proposes a method of grid following and grid forming power electronic devices modelling for short circuit current calculation, as well as a calculation scheme based on fast iterative algorithms. Compared with electromagnetic transient simulation results, the method proposed achieves accuracy and efficiency and is able to provide scientific and effective guidance for short circuit current and power grid strength assessment work in power grid dispatching, planning and other departments.