An Accelerated Multi-Time-Scale Solution of Power Systems Under Multiple Lightning Strokes Events

Intricate model architectures pose substantial challenges to the accuracy and efficiency of lightning surge simulations in large power systems. Conventional methods, relying on fixed time step (FTS) strategy, constrain efficiency when system time constants vary. This paper presents a variable time step and partial element equivalent circuit method (VTS-PEEC), employing VTS strategy that dynamically adjusts according to event-based (EB) criterion and local truncation error (LTE), enabling larger steps in slowly varying regions and smaller ones in rapidly changing regions, thus significantly enhancing computational efficiency. Validated through two test systems, the proposed VTS-PEEC simulation method achieves nearly 2 to 3 orders of magnitude time multiplier of FTS-PEEC while maintaining result consistency. Applied to a 10 kV distribution power system, the VTS-PEEC method calculates the surge response and energy absorption of surge arresters (SAs). The results indicate that SAs face a significant threat when multiple lightning strokes occur on phase wires, therefore, the energy absorption characteristics of SAs under multiple lightning strokes events are further investigated.