Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik
Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level. The Swedish grid is characterized by long distances betweenpower plants and customers, hence long transmission lines carrying loads of varyingsizes are frequent. This implies that reactive power compensation by capacitors willbe necessary. Furthermore, a freedom of choice when to put specific capacitor banksinto operation is desired to keep power losses at a minimum. However, capacitorbank switching at voltage levels below 130 kV is strictly regulated today due to theproblems of transients. The scope of this report is to assess the economic potential ofthe electronic breaker concerning transient-free switching of capacitor banks. Thishas been achieved by comparing two cases of operating systems, controlling the shuntcapacitors in a west-Swedish region network. The first case models todays operationscheme where shunts are divided into four categories, depending on how often theycan be employed. The second case resembles a future situation where all capacitorbanks can be put into/out of operation anytime, hence assuming transient-freeswitching. The two cases were implemented as IPLAN-programs in a PSS/E context.The shunt operations were controlled by an optimal power flow tool. A full year hasbeen succesfully simulated on hour-basis. Load statistics were used in order to resemblehow the active and reactive loads fluctuate over the year. The results show asignificant decrease in active power losses for the future case. Consequently, theeconomic potential for applications of this kind could not be dismissed.