Without Jürgen Kollmannsberger’s design of the on-load tap-changers, no phase shifter goes online.
In order for phase-shifting transformers (PST) to be put into operation, experts like Jürgen Kollmannsberger carry out designs of the installed on-load tap-changers beforehand. The electrical engineer has been supporting MR Sales for many years and develops tap-changer designs for HVDC transformers, furnace transformers, shunt reactors and also phase shifters — of which there are now over 140! Here he explains what is important in this regard.
When you design tap changers for phase-shifting transformers like the ones in Würgau, what is important?
I have to reconcile important key values such as the required overload, the short-circuit impedance of the transformer, the insulating medium and the power factor cosphi with defined performance data of the tap changer such as the maximum permissible switching capacity, the preselector switching capacity and the insulating capacity of the selector. This plays a major role in safe, reliable system operation. It may well take two to five runs before an order is placed.
How long does it take from a PST order to commissioning?
One to two years. However, MR is involved even before that, during the preparation of the offer. Since several transformer manufacturers usually bid on a single project, we sometimes have to carry out four to five designs at the same time. This is very time-consuming and requires a lot of clarification.
Will the investment in a phase shifter pay for itself?
Yes, usually after six months to a year. PSTs regulate the increased feed-in of green power, which affects load flows in the grid. In this way, they replace expensive redispatch measures. Phase shifters are also used in European power trading when energy is purchased when prices are low and sold when prices are high. The payback period here is very short.
Many interpretations, much experience — do you remember any personal highlights?
There are always those. For example, a customer recently called me from the airport on Friday afternoon and asked for technical support. It had to be done quickly so I prepared the presentation with my calculation results by Saturday noon. The customer was very pleased with the uncomplicated and fast support and in the end he won the order. Of course, something like that stays in one’s memory.
