Rapid switching of 11kV capacitor bank successfully tested

Posted by: Gary
Article's Image

We recently undertook a research project to demonstrate that fast capacitor switching satisfies grid code with transient free switching operations. This involved switching an 11kV capacitor bank 100 times in rapid succession with re-energisation within 15 seconds.
Grid code ensures stable, consistent power quality across the network.

Capacitor banks are used to keep voltage to within operational levels, but when de-energised there may be a ‘trapped charge’ on the capacitor. In a standard capacitor bank re-energisation is disabled until sufficient time has passed to allow the capacitor to discharge. In a fast-switched capacitor application this charge is monitored, this allows for fast re-energisation by matching the point of energisation to this charge.

Switching was filmed to create a record of the tests which proved that using the established SynchroTeq MVX technology to control the switching of an 11kV capacitor bank, the need to wait 10 minutes or more to re-energise is removed and repeat switching criteria specified by the grid code of 5 switching events, 15s apart, can be satisfied.

The technology can be used in conjunction with a smaller STATCOM or a stand alone reactive power compensation system (capacitor banks).