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When modeling the propagation of an electric discharge on an ice-covered insulator, the diameter and temperature of the discharge column are vitally important. This paper studies the thermal expansion characteristics of a discharge column occurring after electrode–ice gap breakdown both experimentally and theoretically. It is found that the air part of the discharge channel expands faster and has a higher temperature and larger diameter than the surface part. To provide a quantitative explanation of this phenomenon, a physical model is established based on the gap breakdown process, discharge channel heat conduction, and molecular thermal relaxation theory. The results of theoretical calculations show that the experimentally observed differences in discharge column thermal expansion characteristics result from the heating effect of brush discharge and from differences in heat conduction around the column.

Vehicle semi-active suspension systems can provide a satisfactory compromise of ride comfort and handling stability. With the rapid developments of damping control methodologies, ride comfort is expected to be improved in all three directions, i.e., vertical, roll, and pitch. Considering this kind of multi-objective coordinated control problem, Model Predictive Control (MPC) gains lots of attention in the recent decade. However, the MPC algorithm is expensive for real-time implementations due to its computational complexity. This paper introduces an integrated Skyhook and Linear Quadratic Regulator (LQR) control approach, which can be easily processed on an automotive-grade microcontroller because of its concise algorithm. Meanwhile, it has great potential in attenuating vehicle body vibrations in vertical and rotational directions at the same time. Its control performances are evaluated through the co-simulation between CarSim and MATLAB/Simulink based on three different road conditions. The Buick Enclave, which is a full-size sport utility vehicle (SUV), is modeled in CarSim. The results demonstrated the control efficiency of the integrated Skyhook-LQR approach, which is even better than MPC, especially in vertical and pitch directions.

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