HPS Protection Tests of Emergency Power Units
Check and Documentation of Setting Values and Delay Times
In the event of a power failure during mains parallel operation, the emergency power unit must be disconnected from the supply network. On the one hand, the disconnection from the supply network should take place quickly in order to protect the emergency power unit and the connected consumers. On the other hand, the utility companies are demanding a slower separation from the grid in order not to further endanger the stability of the grid. If there is a sudden loss of large power (power station / wind farm), there is a risk of a national blackout.
The requirements for the grid protection device / grid protection settings depend on the utility company. The utility companies regularly (annually) request compliance with the grid protection settings and tripping times through a precise logging / grid protection test.
To ensure compliance with the grid protection settings, our switchgear and control systems are checked with a high-precision measuring device (Omicron CMC 256plus) before delivery and the results are recorded. For the annual replicate test on site, a special sequence program is used by our trained staff, testing the grid protection devices when the system is not running. A test is then carried out under real conditions (parallel operation with failure of the protection device).
The protection settings are checked in two steps. In the first step, the limit value is approached via a ramp function and the trigger value is documented when the grid protection is triggered (input function). In the second step, the value falls below the limit value once and is then exceeded. When exceeded, the time evaluation is started and stopped via the input signal (triggering grid protection), and documented. With this two-stage protection test, we can precisely record and document the limit values and the delay times.
These protection tests are used in the area of grid decoupling devices but also in the area of protective devices. In the area of generator protection devices, the following protection settings are tested and documented
- Undervoltage protection
- Overvoltage protection
- Underfrequency protection
- Overfrequency protection
- Overcurrent protection
- Short-circuit protection
- Reverse power protection
Fig.: Log view of ramp function (limit value evaluation)
If you have any questions or are interested in our product solutions, our technical sales team will be happy to assist you.