Configuration Selection of Non‐Gap Metal‐Oxide Line Arresters for Switching Overvoltage Suppression in HVAC Power Systems
Tongwei Guo, Tao Liang, Wei Shen, Sen Wang, Xinyi Liu, Jie Guo, Yanzhao XieABSTRACT
Switching overvoltage is a critical factor governing insulation coordination in high‐voltage alternating‐current (HVAC) systems. Existing mitigation measures, including breaker closing resistors, shunt reactors, controlled switching and controllable arresters, can reduce switching surges but may introduce additional mechanical complexity, maintenance burden, cost, or technology‐maturity concerns. This paper presents a configuration‐selection framework for applying non‐gap metal‐oxide line arresters (NGLAs) to suppress switching overvoltage in canonical 750 kV HVAC lines. The novelty lies in using a high‐position‐resolution ATP‐MATLAB co‐simulation routine to connect statistical switching‐overvoltage indices with arrester location, rated voltage and energy sharing, thereby deriving practical single‐ and dual‐NGLA configuration rules rather than only evaluating a fixed arrester layout. In the framework, ATP‐EMTP models the frequency‐dependent line, statistical breaker operation and MOV nonlinearity, while MATLAB automatically updates NGLA positions at 5 km resolution and evaluates the expected 2% switching overvoltage V 2% , the maximum overvoltage along the line and arrester energy absorption. The selected configuration must satisfy V max,2% ≤ 1.8 p.u. and E max ≤ 6 MJ and the preferred location is identified by minimising the maximum V 2% and balancing arrester energy absorption. Results show that a single 600 kV NGLA installed near 5%–7% of the line length from the far end can reduce the maximum switching overvoltage of a 400 km line from 2.00 p.u. to 1.78 p.u., while a dual‐NGLA configuration at 50 km and 25 km from the far end further reduces it to 1.69 p.u. and distributes energy absorption among the arresters. The study provides an engineering‐oriented alternative for switching‐overvoltage suppression in HVAC systems and clarifies the applicable conditions and limitations of the proposed configuration rules.