Overview
As critical equipment linking the power grid to new energy vehicles, EV charging stations integrate AC/DC power modules, control MCUs, communication modules, and various precision electronic components.
Because charging stations typically operate outdoors for extended periods and connect directly to the power grid, they are susceptible to various forms of electrical interference. Such interference can damage charging modules, control systems, and even battery management systems (BMS).
Consequently, reliable surge protection schemes are essential in charging station design, employing multi-stage protection strategies using components such as GDTs, MOVs, and high-power TVS diodes.
Semiware’s AK series high-power TVS diodes feature high surge-handling capability, low clamping voltage, and fast response times, making them ideal for surge protection designs in EV chargers, charging modules, and energy storage systems.
I. What Surge Threats Do Charging Stations Face?
1.1 Lightning Surges
Charging stations are typically installed outdoors and are vulnerable to:
- Direct lightning strikes
- Electromagnetic induction from nearby lightning strikes
- Lightning surges entering via overhead power lines
These events can generate high-amplitude transient voltages and currents within the circuitry.
1.2 Grid-Induced Transient Overvoltage
Due to the complex nature of the power grid, surges can arise from:
- Grid switching operations
- Recovery from line faults
- Startup and shutdown of large equipment
- Voltage fluctuations
These transient overvoltages can affect the internal power modules and control circuits of the charging station.
1.3 Internal Load Switching
Charging stations contain high-power energy conversion modules; during operation, the following can occur:
- High-speed switching of power components
- Rapid changes in current
- Reverse voltage generation from inductive loads
These factors can also create transient interference.
II. Design Principles for Charging Station Surge Protection
2.1 Multi-Stage Protection Principle
- GDT: Withstands high-energy surges and discharges the majority of the energy
- MOV: Reduces transient overvoltage
- TVS: Provides precise voltage clamping to protect sensitive electronic components
2.2 High Surge-Handling Capability
Protective components must be capable of withstanding surge impacts as required by standards such as IEC 61000-4-5.
2.3 Low Residual Voltage Protection
After surge discharge, the protection device should reduce the residual voltage at the output to prevent secondary damage to downstream components.
2.4 Fast Response
For sensitive circuits such as MCUs and communication modules, the protection device must act rapidly to limit transient voltages.
III. Why Choose High-Power TVS Diodes for Charging Piles?
Standard TVS diodes are typically suited for low-power electronic devices; however, charging piles operate in environments exposed to higher-level surges and require superior energy absorption capabilities.
Semiware’s AK Series High-Power TVS Diodes offer the following advantages:
3.1 High Surge Absorption Capability
The AK series includes models AK3, AK6, AK10, AK16, and AK20, with a maximum peak pulse current (Ipp) of up to 20kA.
3.2 Excellent Clamping Performance
Featuring an optimized structural design, the AK series rapidly limits peak voltage during a surge event, thereby reducing the transient stress experienced by downstream circuitry.
3.3 Low Leakage Current Design
- Reduces power loss during normal operation
- Lowers component heat generation
- Enhances long-term system reliability
IV. Semiware AK Series TVS Protection Solution for Charging Piles
The following AK series models are recommended for EV charger applications:
| Part Number | VRWM(V) | VC(V) | 8/20μs Surge |
| AK3-042C | 42 | 105 | 3kA |
| AK3-380C | 380 | 520 | 3kA |
| AK3-430C | 430 | 625 | 3kA |
| AK6-058C | 58 | 110 | 6kA |
| AK6-076C | 76 | 140 | 6kA |
| AK6-380C | 380 | 520 | 6kA |
| AK6-430C | 430 | 625 | 6kA |
AK Series High Current TVS Diode Datasheet:
Conclusion
Semiware’s AK series high-power TVS diodes offer surge withstand capabilities ranging from 3kA to 20kA. Combined with low clamping voltage and a highly reliable design, they provide an efficient surge protection solution for charging piles and energy storage systems.
For more information about Semiware AK Series high power TVS diodes, please contact our technical team.
