As electric vehicles, advanced battery systems and high-power charging infrastructure continue to evolve, electrical safety is becoming increasingly important. Higher voltages and currents create new challenges for circuit protection, particularly when dealing with short circuits and overcurrent conditions. Sensata Technologies offers advanced fast disconnect solutions, including its GigaFuse and PyroFuse technologies, designed to provide rapid and reliable protection in demanding high-voltage applications.
The growing need for fast circuit protection
The transition towards electrification is driving the development of increasingly powerful electrical systems. From electric commercial vehicles and battery energy storage to megawatt charging infrastructure, these applications require components capable of handling high continuous currents while maintaining reliable protection against electrical faults.
In high-voltage DC systems, short circuits can generate extremely high fault currents within milliseconds. Conventional protection technologies may face limitations in terms of interruption speed, thermal performance and coordination with other switching components.Fast disconnect devices provide an important additional layer of protection by rapidly isolating electrical circuits when abnormal conditions occur.
Sensata Technologies has developed two complementary solutions to address these challenges.
- GigaFuse: provides passive electromechanical protection
- PyroFuse: uses an externally triggered pyrotechnic mechanism.
GigaFuse: passive protection without external electronics
The Sensata GigaFuse is a fast-acting electromechanical circuit protection device designed for advanced battery systems and high-voltage applications. Unlike conventional thermal fuses, the GigaFuse uses a passive triggering mechanism that responds directly to excessive current. This allows the device to disconnect the circuit without relying on an external power supply, battery management system (BMS) or electronic overcurrent detection.
The GigaFuse GFP400 is available in passive and combined passive/active configurations, providing engineers with flexibility when designing protection architectures.
Key features of the GigaFuse GFP400 include:
- Rated voltage of 1,000 V DC
- Continuous current rating of 400 A, depending on application conditions
- Maximum breaking power of up to 10 MW under specified conditions
- Fast fault clearing, with a typical 3 ms clear time at 10 MW
- Adjustable trip thresholds for coordination with high-voltage contactors
- Optional external triggering functionality
- Low electrical resistance, reducing heat generation during normal operation
An important advantage of GigaFuse technology is its ability to provide protection independently of external control electronics. This makes it particularly suitable for applications where reliable fault interruption is essential, even if electronic control systems become unavailable.
PyroFuse: ultra-fast active circuit interruption
For applications requiring externally controlled fault interruption, Sensata offers the STPS500 PyroFuse. This pyrotechnic circuit breaker is designed to rapidly and permanently disconnect high-voltage circuits following an external trigger signal. The PyroFuse can be activated by a suitable protection controller in response to events such as short circuits or vehicle accidents, providing an additional safety mechanism for high-energy electrical systems.
Key features of the STPS500 PyroFuse include:
- Maximum continuous current rating of 500 A
- Breaking capacity of 20 kA at 500 V or 16 kA at 1,000 V under specified test conditions
- Disconnect action time of less than 1 ms, excluding external detection time
- High post-interruption insulation resistance of at least 50 MΩ at 1,000 V
- Bidirectional operation
- Compact, lightweight construction
- Fully enclosed housing designed to prevent gas release during interruption
Thanks to its extremely fast response and high breaking capacity, the PyroFuse is particularly suitable for electric vehicles, charging infrastructure, aerospace applications and industrial high-voltage systems.
Combining fast disconnect devices with high-voltage contactors
In modern high-voltage systems, contactors and fast disconnect devices perform complementary functions. Contactors are designed to switch electrical circuits during normal operation, such as connecting and disconnecting batteries or controlling charging power. However, their ability to interrupt extreme short-circuit currents may be limited. Fast disconnect devices provide an additional level of protection by interrupting fault currents that exceed the contactor’s breaking capability.
For example, Sensata’s GIGAVAC GXVB611 contactor is designed for high-voltage DC switching, offering a rated voltage of 1,000 V DC and a nominal current of 600 A.
When combined with a suitable PyroFuse or GigaFuse, engineers can develop coordinated protection systems that combine reliable operational switching with rapid emergency disconnection. Correct coordination between the contactor and fast disconnect device is essential to ensure that each component operates within its specified electrical limits.
Applications in megawatt EV charging
One of the most demanding applications for high-voltage protection technology is megawatt EV charging. As electric trucks and other heavy-duty vehicles adopt larger battery packs, charging infrastructure must deliver significantly higher power levels to reduce charging times. Megawatt Charging Systems can operate at power levels approaching 3.75 MW and voltages of approximately 1,250 V DC, creating substantial demands on switching, thermal management and circuit protection.
Within these systems, high-voltage distribution units manage power distribution, switching, monitoring and protection. Sensata’s contactors and fast disconnect technologies can contribute to these architectures by providing reliable switching and rapid fault isolation. For example, the GXVB611 contactor can be used within the charging system’s switching matrix, while the STPS500 PyroFuse provides additional short-circuit protection in applications operating within its specified voltage and current ratings.
At higher system voltages, other appropriately rated switching and protection solutions must be selected.
Supporting safer and more reliable electrification
As electrical systems become more powerful, the importance of coordinated circuit protection continues to increase. Sensata’s GigaFuse and PyroFuse technologies offer different approaches to fast circuit interruption, allowing engineers to select passive, active or combined protection strategies according to their application requirements. By integrating these technologies with suitable high-voltage contactors, system designers can improve fault protection, support thermal efficiency and develop more robust electrical architectures.
Discover Sensata’s high-voltage protection solutions at Nijkerk Electronics
Nijkerk Electronics offers a broad portfolio of advanced electronic components and power solutions, including high-voltage switching and circuit protection technologies from Sensata Technologies. Whether you are developing electric vehicle charging infrastructure, battery systems or industrial electrification solutions, selecting the right protection components is essential for safe and reliable operation.
If you want more information or if you have any questions, please contact Nijkerk Electronics!