Voltage limiting device HVL
Voltage limiting device for DC traction systems
Voltage limiting device HVL consists of the parallel connection of a metal-oxide (MO) surge arrester with no spark gaps and two anti-parallel connected thyristors. Transient surges caused by lightning and switching operations in the system are limited by the MO arrester. If surges occur for a longer period of time (milliseconds to hours) due to faults in the system or for operational reasons, the thyristors fire to limit touch voltages. As soon as a zero-current transition occurs, the thyristors cut off the current flow and the original condition is restored. The whole device is molded in silicone, designed and tested according to EN 50122-1 (IEC 62128-1), EN 50123-5 (IEC 61992-5), EN 50526-1 (IEC 62848-1).
Voltage limiting devices are used to prevent impermissible touch voltages in DC traction systems in normal operations and in fault conditions by bonding the return circuit of a DC railway system to the earthing system or to the exposed conductive parts.
Voltage limiting devices are available for nominal triggering voltage 60 V and 120 V.
Applications
- HVL compiles with both VLD-O (normal operation) and VLD-F (fault) functionality in the specified current range
Why Hitachi Energy?
- Over 100 years of experience in overvoltage protection and more than 30 years with silicone insulation
- Local and global Hitachi Energy application support
- Own production of metal-oxide (MO) resistors
- Mechanically strong design
- UV resistant silicone housing with excellent pollution performance
- Voltage limiting device HVL does not require power supply
Brief performance data
| HVL-60 | HVL-120 | ||
|---|---|---|---|
| Normal triggering voltage | V | 60 | 120 |
| DC short-time withstand current at 100 ms - recoverable | kA | 2.1 | 2.1 |
| DC short-time withstand current at 100 ms - non-recoverable | kA | 20 | 20 |
| Discharge current (In) | kA | 25 | 25 |
| High current impulse with wave 8/20 µs | kA | 80 | 80 |
| High current impulse with wave 10/350 µs | As | 12 | 12 |
For more details see the data sheet in downloads below.
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