Single Phase AC Series Circuits

Single Phase AC Series Circuits

AC Circuits

Alternating current (AC) circuits involve the transmission of current that varies cyclically between positive and negative peaks. They differ from direct current (DC) circuits, where the current flows in one direction continually. AC circuits have several advantages over DC circuits, including the ability to transmit electricity over long distances without significant energy loss and the efficient transfer of energy from generators to loads.

Impedance

Impedance is the total opposition to the flow of alternating current in an AC circuit. It is given by the formula Z = R + jX, where R represents resistance and X represents reactance. Reactance is the opposition to the flow of current due to inductive or capacitative effects. Impedance is a complex quantity, and its magnitude and phase angle depend on the type of load in the circuit.

Series Circuits

In a series circuit, components are connected end-to-end, forming a continuous path for the current flow. For example, a single-phase AC circuit can consist of a resistor, an inductor, and a capacitor connected in series across a single-frequency source. The total impedance of a series circuit is the phasor sum of the individual components, and the magnitude of the impedance is the highest among the individual components. At resonance, when the inductive reactance equals the capacitive reactance, the total impedance becomes real, and the circuit operates at unity power factor.

Resonance

Resonance occurs in an AC circuit when the inductive reactance and capacitive reactance cancel each other out. In a series resonant circuit, the inductive reactance is equal to the capacitive reactance, resulting in a zero net reactance. At this point, the circuit experiences maximum impedance, and the power factor reaches unity, indicating the ideal power transfer condition.

Power Factor

The power factor of an AC circuit indicates how efficiently the circuit utilizes the available power. It is the ratio of the active power to the apparent power. Improving the power factor helps reduce the line losses and increase the efficiency of the circuit.