Semikron SKKH 570/18 E | High-Reliability Thyristor/Diode Module for Demanding Power Control
The Semikron SKKH 570/18 E is a high-power thyristor/diode module engineered for superior reliability and precise control in the most demanding industrial applications. Housed in the industry-proven SEMIPACK® 3 package, this module integrates two thyristors in a half-bridge (dual) configuration. It is specifically designed not for high-frequency switching like an IGBT, but for robust, line-frequency power regulation tasks where fault tolerance and raw power handling are paramount. For engineers designing systems like controlled rectifiers, AC controllers, and high-power soft starters, the SKKH 570/18 E delivers a battle-tested solution that balances performance with exceptional operational lifespan.
Key Technical Specifications at a Glance
This table provides a summary of the critical performance parameters for the SKKH 570/18 E. These values are essential for preliminary design and component evaluation.
| Parameter | Value |
|---|---|
| Repetitive Peak Off-State Voltage (VDRM/VRRM) | 1800 V |
| Average On-State Current (IT(AV)) @ Tcase=85°C | 570 A |
| Surge On-State Current (ITSM) @ 10ms, 50Hz | 15500 A |
| Isolation Voltage (Visol) | 3600 V (AC, 1 minute) |
| Operating Junction Temperature (Tvj op) | -40°C to 125°C |
| Package | SEMIPACK® 3 |
Technical Deep Dive: The Engineering Behind the SKKH 570/18 E
Two core technologies define the performance and reliability of the Semikron SKKH 570/18 E:
- Robust Phase Control Thyristor Technology: Unlike the gate-controlled turn-off capability of an IGBT, a thyristor (or Silicon Controlled Rectifier, SCR) is a latching device. The SKKH 570/18 E leverages this principle for phase angle control. By precisely timing the gate trigger pulse within each AC half-cycle, engineers can regulate the amount of power delivered to a load. This method is exceptionally efficient and rugged, making it ideal for controlling large resistive and inductive loads without the complexity and potential EMI challenges of high-frequency PWM switching.
- High-Integrity Isolated Baseplate: The module is built upon an aluminum oxide (Al2O3) Direct Bonded Copper (DBC) substrate. This construction provides excellent electrical isolation between the power terminals and the heatsink, simplifying thermal design and enhancing system safety. More importantly, it offers a low thermal resistance path, ensuring that heat generated during high-current operation is efficiently transferred away from the silicon die. This superior thermal management is critical for preventing device failure and ensuring a long service life under heavy cyclic loads.
Application Scenarios and Value Proposition
The unique characteristics of the SKKH 570/18 E make it the optimal choice for several key industrial power conversion systems:
- Controlled Bridge Rectifiers: In applications requiring a variable DC voltage output from an AC source, such as DC motor drives or battery chargers, this module forms the core of a fully controlled rectifier. Its 1800V rating provides a significant safety margin for operation on 400V/480V three-phase lines.
- AC Voltage Controllers & Soft Starters: For large induction motors, an abrupt start can cause severe mechanical stress and electrical inrush currents. The SKKH 570/18 E can be used in an AC controller topology to gradually ramp up the voltage, providing a smooth, controlled start that reduces wear on mechanical components and minimizes voltage sag on the power grid.
- High-Power Welding Systems: In certain resistance welding applications, thyristors are used for precise, high-current AC switching. The module's impressive surge current capability (ITSM) ensures it can withstand the demanding pulses required for these processes.
Frequently Asked Questions (FAQ)
1. How does the SKKH 570/18 E differ from an IGBT module in a motor drive application?
The fundamental difference lies in their switching capability and control method. An IGBT is a high-frequency switch (kHz range) used in inverters to create a variable frequency, variable voltage output, enabling precise speed and torque control in modern servo drives and VFDs. The SKKH 570/18 E, a thyristor module, operates at line frequency (50/60 Hz) and controls power by varying the conduction angle. It is used for simpler DC motor control (via a controlled rectifier) or for soft-starting AC motors, but not for frequency control. In short, choose IGBT modules for sophisticated inverter-based control and thyristor modules like this one for robust, line-frequency power regulation.
2. What are the key considerations for the gate drive circuit for this thyristor module?
Unlike an IGBT gate drive which requires a continuous voltage to maintain the ON state, a thyristor only needs a short, sufficiently strong current pulse to latch on. Key considerations include: 1) Ensuring the gate current (IGT) and voltage (VGT) meet the datasheet minimums to guarantee firing under all temperature conditions. 2) For inductive loads, a sustained or "back-porch" pulse train is often recommended to ensure the thyristor remains latched until the load current exceeds the holding current. 3) Providing electrical isolation between the control logic and the high-voltage gate circuit is mandatory for safety and noise immunity.
For detailed application support or to discuss how the Semikron SKKH 570/18 E can enhance your power system design, please contact our technical team for expert guidance and sourcing.
