Main application fields of High-voltage DC relays

High-voltage Dc Relays are the core components of the high-voltage system in new energy vehicles, widely used in battery management systems (BMS), charging circuits, main circuit control, high-voltage auxiliary systems (air conditioning, PTC heaters), etc., to achieve the on-off control of high-voltage battery packs and the vehicle's circuit, the circuit switching during charging, and the rapid power-off protection in case of faults. They are the key defense line for vehicle high-voltage safety. Usually, a new energy vehicle needs to be equipped with 5 to 10 different specifications of high-voltage DC relays, covering multiple circuits such as main positive, main negative, pre-charge, fast charge, and slow charge.

High-voltage DC relays are used in electrochemical energy storage stations, household energy storage, portable energy storage, etc., for the string control of battery clusters, charging and discharging circuit switching, DC combiner cabinets, PCS (energy storage converters) on the DC side, and emergency disconnection in case of faults, to ensure the circuit safety of the energy storage system in different states such as charging and discharging, grid connection, and off-grid. With the rapid development of shared energy storage and grid-side energy storage, the demand for high-voltage high-current DC relays in the market is increasing.

High-voltage DC relays can be used in DC combiner boxes of photovoltaic arrays, DC sides of string inverters, DC boosting systems of photovoltaic power, to achieve the switching control of photovoltaic string, and rapid isolation in case of faults, avoiding the high-voltage DC current generated by photovoltaic modules causing equipment burning or fire risks. At the same time, they are also widely used in pitch control systems of wind power generation, DC conversion links, and have a large number of applications.

In the traction power supply system and auxiliary power supply system of subways, light rails, and high-speed trains, high-voltage DC relays are used for the on-off control of DC traction circuits, the charging and discharging management of battery packs, circuit isolation during vehicle maintenance, and protection of the DC power supply system at the platform, meeting the requirements of high reliability, high vibration, and large current impact in rail transportation.

High-voltage DC relays can also be applied in DC charging stations, DC distribution systems, UPS uninterruptible power supplies, industrial DC speed control systems, electroplating power supplies, and DC power supply systems of communication base stations, to achieve the on-off control and fault protection of large-power DC loads. Among them, high-voltage DC charging stations usually require the use of DC relays with rated voltages of 1000V to 1500V and rated currents of 30A to 250A to support the circuit control requirements of high-power fast charging.

High-voltage DC relays are used in the DC power supply systems of aerospace vehicles, ship power systems, high-voltage DC power supplies of military equipment, and high-voltage circuits of radar transmitters in aerospace, undertaking the core switching function, meeting special requirements such as high reliability, high environmental adaptability, and anti-interference.