Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
In this type of tariff, The total charge is divided into two components: fixed charges and running charges. The fixed charges depend upon the number of units consumed by the consumer. It can be expressed as Total Cost = [A (kW) + B (kWh)] Rs. A = charge per kW of max demand (A is a constant which when multiplied with max demand (kW) gives the total fixed costs.) B = charge per kWh of energy consumed (B is a constant which when multiplied with units consumed (kWh), gives total running charges.)
When voltage changes occur in rapid succession, with magnitudes large enough to cause lighting level variations. The human eye-brain response is most sensitive to periodic r.m.s. voltage changes that occur at around 8 - 10 cycles per second.