SLVAF35 February   2021 DRV8714-Q1 , TPS2HB16-Q1


  1. 1Introduction
  2. 2 Contactors Distribution in EVs and HEVs
  3. 3 Power-up Sequence
  4. 4 Coil Types and Control Requirements
  5. 5 Coil Driving Implementation
    1. 5.1 Pulse Width Modulation Current Generation
    2. 5.2 Adjustable Supply Voltage Approach
  6. 6 Summary


A high-voltage contactor, also called a high-voltage relay without distinction in the industry, is widely used in electric vehicles (EV) and hybrid electric vehicles (HEV). It is an electromechanical switching device with a coil to generate a magnetic force that mechanically operates an electric contact. However, it is more common to use a high-voltage contactor to represent high-power applications in EV and HEVs.

As a key safety device in new energy vehicles, a high-voltage contactor needs basic functions that are resistant to high voltage, load, shock, strong arc extinguishing, and breaking capacity. An appropriate current is applied to the coil to ensure proper force to drive the contacts for robust operation. Even though there are many different types of contactors for different functions in a vehicle, the driving current profiles of all the contactor coils are similar.

This article gives a general introduction of the high-voltage contactors in EV and HEVs, and presents several approaches on how to drive the high-voltage contactors.