COORDINATED OPERATION OF TSO, DSO AND CONSUMERS IN VOLTAGE MANAGEMENT IN CASE OF INTERCONNECTING LARGE AMOUNT OF PV

In Japan, power company TSO in each region has been operating the transmission system of voltage 66kV or more, DSO has been operating the distribution system of following voltage 6.6kV. In addition, Customers have been operating the distributed power generations of the customer. Before photovoltaic generations (PV) becoming large amount of interconnection to the power system, TSO, DSO and customer was little need for cooperation in the voltage management. However, in case of becoming large amount, in social cost and technical aspects, TSO, DSO and customers came out needs to be coordinated. In this paper, the voltage control method of transformer in distribution substation (DSS) that adopted as equipment of the current state are schedule control, scalar type load drop compensation (LDC) and vector type LDC. We evaluated the effect of the system voltage regulation about these voltage control method and clear most suitable voltage control method, in order to clarify the coordination methods and the roles of TSO, DSO and customers. As a result, as a countermeasure to the PV interconnection of the order of 40% relative to the peak power of the load, in the control of the transformer of DSS, it was the most effective control method is vector type LDC. Further, by making the power factor (pf) constant control of PV is applied, it was found to be further corresponding to the connection of a large amount of PV.