The Problem In Detail
Initial simulation studies of the transformer showed that there would be a significant voltage dip of up to 18% on the 132kV system when the transformer was energised which exceeded the limits stipulated by Scottish Power.
Finding the Solution
Powersystems engaged Enspec to supply and commission a Vizimax SynchroTeq Plus Point-on-Wave Switching device to control the energisation of the 90 MVA 132/33 kV transformer at Aikengall II Wind Farm.
Making it all Work
Enspec engineers reviewed the primary plant layout to ensure the correct VT, CT, and circuit breaker positioning to allow the scheme to work and carried out on-site commissioning to correctly configure the SynchroTeq in terms of circuit breaker timing.
What that means for the project now
The SynchroTeq Plus successfully reduced the transformer inrush current to 0.3pu and reduced the 132kV voltage dip to 0.6% to bring it in line with limits stipulated by Scottish Power. The device has now been in operation for over 3 years and continues to mitigate the transformers inrush current providing ongoing P28 compliance for Aikengall II Wind Farm.
What Powersystems say...
"Powersystems UK engaged Enspec to provide a SynchroTeq for Aikengall II Wind Farm, their engineers were very helpful with reviewing the wiring diagrams and also provided great support on-site throughout the commissioning. The SynchroTeq reduced the 132kV voltage dip to 0.6% from a predicted 18%. Powersystems see the SynchroTeq as a great option for mitigating inrush current, even on large grid-scale transformers." Ross Falconer, Lead Electrical Design Engineer.