What is a new energy high voltage DC contactor?
New energy high voltage DC contactor (High Voltage DC Contactor) is a key electrical component used to control the on and off of high voltage DC (usually 300V-1000V) circuits, mainly used in new energy vehicles (EV/HEV) and charging piles. Its core functions include:
(1). Safe on and off high voltage circuit: Reliable switching of high voltage power supply during vehicle startup, charging, and failure.
(2). High current impact resistance: Carry hundreds of amperes of current to ensure low contact resistance and low heat generation.
(3). Long life and high reliability: It must meet a mechanical life of more than 100,000 times and adapt to harsh working conditions (vibration, high temperature, arc).
Currently, the world's mainstream brands include TE Connectivity USA, Omron Japan, and Xiamen Hongfa China. Our core team comes from Xiamen Hongfa Group, with more than 10 years of industry experience and mastering the design, manufacturing, and core technology of high-voltage DC contactors.
Main components of new energy high-voltage DC contactors
The performance of high-voltage DC contactors depends on the materials and processes of their core components. Our company mainly deals in the following key components:
| Part name | Material and characteristics | Technical core requirements | Application scenarios |
| Copper moving contact plate | High-purity copper (≥99.9%), stamping, high conductivity, low contact resistance | Surface flatness (Ra≤0.8μm), arc erosion resistance | Main Moving Silver Contact dynamic on-off |
| Copper stud static contact | Copper turning + silver plating, optimize current distribution, reduce heat | Thread accuracy (±0.01mm), silver plating thickness (≥3μm) | Static Silver Contact, cooperates with moving contact plate |
| Electrical pure iron yoke | High magnetic permeability pure iron (DT4), precision stamping, enhanced electromagnetic attraction | Magnetic permeability ≥5000, no magnetic aging | Electromagnetic system magnetic circuit |
| Electrical pure iron armature | Pure iron material, low remanence, ensure fast response | Hardness HRB ≥ 65, fatigue resistance | Electromagnetic drive components |
| Metalized ceramic | Alumina ceramic (Al₂O₃) + metalized coating, insulation, and high voltage resistance (≥ 5kV) | Air tightness (helium leak rate ≤ 1×10⁻⁸ Pa·m³/s) | Insulated shell, isolating high-voltage and low-voltage circuits |
Application of new energy high-voltage DC contactors in new energy vehicles and charging piles
(1) New energy vehicles (EV/HEV)
High-voltage battery management system (BMS): The contactor is used to switch the main positive/main negative circuit of the battery pack to ensure safe charging and discharging.
Motor controller: Switches the high-voltage power supply of the drive motor and needs to withstand frequent start-stop current shocks.
Fast charging system: Carrying large current (such as 400A@800V) during DC fast charging, requiring low contact heating and zero welding risk.
(2) Charging pile (DC Charging Pile)
DC charging module: Controls the high-voltage connection between the charging pile and the vehicle battery, and must have high insulation and arc resistance.
Fault protection: Quickly disconnect the circuit in the event of a short circuit or overload to protect the safety of equipment and users.
Typical working scenario comparison:
| Parameters | New energy vehicles | Charging pile |
| Voltage range | 300V-800V | 200V-1000V |
| Current requirement | 200A-500A | 100A-400A |
| Switching frequency | Medium frequency (action during start-stop) | Low frequency (on and off during the charging cycle) |
| Core challenges | Vibration resistance, high-temperature resistance | Long life, high voltage arc resistance |
Production process and quality control of our core components
(1) Copper moving contact plate & copper stud static contact
Material: C1100 high-conductivity copper (conductivity ≥100% IACS) is used, and the Xiamen Hongfa supply chain guarantees purity.
Process:
Precision stamping (tolerance ±0.02mm) → Deburring and polishing → Silver plating (3-5μm) → Laser flatness detection.
Quality inspection:
- Contact resistance test (≤50μΩ)
- Arc erosion simulation (wear loss ≤10% after 100,000 on-off cycles)
(2) Electrical pure iron yoke & armature
Material: DT4 electrical pure iron (carbon content ≤0.02%), magnetic permeability is better than ordinary steel.
Process:
- High-speed stamping → Annealing treatment (stress relief) → Anti-rust coating → Magnetic property detection.
Quality inspection:
- Residual magnetic strength ≤0.05T, ensuring rapid release of the electromagnetic system.
(3) Metallized ceramics
Material: 96% alumina ceramics, metalized layer is molybdenum-manganese alloy + nickel plating.
Process:
- Ceramic sintering → Metallized coating → High temperature brazing → Helium mass spectrometer leak detection.
Quality inspection:
- Insulation withstand voltage ≥5kV/1min, leakage current ≤1mA.
Core advantages of our company
1. Technology inheritance: The core team comes from Xiamen Hongfa and masters the full process technology of high-voltage DC contactors.
2. Material advantages: Cooperate with leading suppliers to ensure that the performance of materials such as copper, pure iron, and ceramics meets the standards.
3. Strict quality control:
- Destructive testing is carried out on each batch (such as a contact welding test).
- 100% inspection of key parameters (size, resistance, insulation).
4. Customized service: Parameters such as contact size and coating thickness can be adjusted according to customer needs.
New energy high-voltage DC contactors are the "safety switches" for electric vehicles and charging piles. Their reliability directly depends on the performance of core components such as red copper moving contact plates, static contacts, electrical pure iron parts, and metalized ceramics. With the technical background of the Hongfa system, precision manufacturing capabilities, and strict quality control, our company provides global customers with high-performance and long-life contactor component solutions to help the safe development of the new energy industry.
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