Lightning protection measures for the hottest subs

Lightning protection measures for substations

substations are an important part of the power system. Lightning accidents in substations will cause large-scale power outages and cause great harm to electricity, which requires that lightning protection measures must be very reliable

the lightning strike suffered by the substation mainly comes from two aspects: first, the lightning strike directly on the electrical equipment of the substation; Second, the lightning wave formed by induced lightning overvoltage and direct lightning overvoltage of overhead lines invades the substation along the line. Therefore, the protection of direct lightning strike and lightning intrusion wave against the damage of substation incoming line and transformer is very important. It can detect the torque under 1 fixed angle

direct lightning protection of substation. Installing lightning rod is the main measure of direct lightning protection, and lightning rod is the lightning receiver to protect electrical equipment and buildings from direct lightning strike. It attracts the thunder to itself and leads it safely into the ground, thus protecting the nearby equipment with lower insulation level from lightning strike

when installing lightning rods, the 35 kV substation must be equipped with independent lightning rods and meet the requirements of no counterattack; For substations of 110 kV and above, due to the high insulation level of distribution devices with such voltage levels, lightning rods can be directly installed on the structure of distribution devices. Therefore, the high potential generated by lightning rods will not cause counterattack accidents of electrical equipment

substation protection against lightning intrusion wave. The main measure of substation to protect against intrusion wave is to install valve arrester or protective gap on its incoming line. The basic components of valve type arresters are spark gap and nonlinear resistance. At present, FS series valve type arresters are spark gap and nonlinear resistance, which are mainly used to protect small capacity distribution devices. SFz series valve type arresters are mainly used to protect the electrical equipment of medium and large capacity substations; Fcz1 series magnetic blow valve arresters are mainly used to protect high-voltage electrical equipment in substations

incoming line protection of substation. The purpose of implementing lightning protection for the incoming line of the substation is to limit the amplitude of lightning current flowing through the arrester and the steepness of lightning wave. When overvoltage occurs on the line, there will be traveling waves traveling along the conductor to the substation, and its amplitude is 50% of the impulse flashover voltage of the line insulation with the policy of "made in China 2025". The impulse withstand voltage of the line is much higher than that of the substation equipment. Therefore, installing lightning protection wire on the incoming line close to the substation is the main measure for lightning protection. If the lightning conductor is not erected, when the incoming line close to the substation is struck by lightning, the amplitude of lightning current flowing through the arrester can exceed 5 Ka, and its steepness will also exceed the allowable value, which is bound to cause damage to the line

transformer protection. The basic protection measure of the transformer is to install lightning arrester close to the transformer, so as to prevent the insulation from being damaged by the lightning wave invaded by the line

when installing lightning arrester, it should be as close to the transformer as possible, and the length of the connection should be reduced as far as possible, so as to reduce the voltage drop of lightning current on the connection line. At the same time, the wiring of the arrester should be connected with the metal shell of the transformer and the neutral point at the low-voltage side, so that when the intrusion wave makes the arrester 2 When the cement bending and compression resistance test is operated mechanically, the voltage acting on the main insulation on the high-voltage side is only the residual voltage of the arrester (excluding the voltage drop on the grounding resistance), which reduces the chance of lightning damage to the transformer

lightning protection and grounding of substation. After the lightning protection such as experimental force, peak value, displacement, speed, experimental state and experimental curve can be synchronously displayed in the substation, a unified grounding should be laid according to the requirements of safety and working grounding, and then the grounding body should be added under the lightning rod and arrester to meet the requirements of lightning protection, or a separate grounding body should be laid under the lightning protection device