Transient-free switching provides long-life utilization of electrical components like CBs, transformers, shunt reactors/capacitor, etc. and prevents voltage sag problem of weak power systems. DENATSU Electronics’ Transient-Free Controller is used with single-pole CBs/contactors to control their ON and OFF times for the loads of which generate transients at LV, MV and HV applications. By utilizing the controller with 3 pieces of single-pole CBs, it is also suitable for transient free switching of shunt reactors/capacitors used for voltage regulation purpose at HV buses.
Moreover, by using our controller with single-pole contactors (or 3-pole CB as single-pole switchgear for each phase), shunt reactor and capacitor banks can be switched without any transients at MV level for reactive power compensation. Requirement of RC snubber circuits during switching OFF of the highly inductive loads such as shunt reactors is mitigated by use of the controller. Furthermore, by configuring the switching instants of CBs, it also enables to perform dynamic short circuit withstand tests of various power system components such as fuses and switches, transformers etc. for high power test laboratories
Practical Case: Switching of Shunt Reactors
Current waveforms of shunt reactors with and without the controller are shown in above graphs. As seen in Figure 1, high peak currents are observed without the utilization of the controller. No any transient exist when our transient-free controller is used with the single-pole contactors/CBs.