Centralized voltage control apparatus and centralized voltage control system

A centralized voltage control system comprising:

• a plurality of voltage controllers to control voltage of a distribution line of a distribution system, the voltage controllers being connected to the distribution line;
• a plurality of local voltage controllers to control, in a one-to-one correspondence, the plurality of voltage controllers;
• a centralized voltage control apparatus connected to the plurality of local voltage controllers via a communication network;
• and
• a measuring circuit to measure voltage of the distribution line, wherein the centralized voltage control apparatus includes:
• calculation circuitry to calculate a control variable for each of the plurality of voltage controllers on the basis of a measured value of voltage at each measurement point measured by the measuring circuit and a proper voltage range at each measurement point;
• and
• command circuitry to give a command value to each of the plurality of local voltage controllers on the basis of the control variable, and
• when a measurement becomes impossible at a first measurement point that is the measurement point, an estimated value of a change in voltage of the distribution line is calculated for a section between a second measurement point that is the measurement point located upstream of the first measurement point and a third measurement point that is the measurement point located downstream of the first measurement point, and the proper voltage range at the second measurement point is changed on the basis of the estimated value.