formula for calculating power in rlc series circuit
Answers
Thus far we have seen that the three basic passive components of: Resistance, Inductance, and Capacitance have very different phase relationships to each other when connected to a sinusoidal alternating supply.
In a pure ohmic resistor the voltage waveforms are “in-phase” with the current. In a pure inductance the voltage waveform “leads” the current by 90o, giving us the expression of: ELI. In a pure capacitance the voltage waveform “lags” the current by 90o, giving us the expression of: ICE.
This Phase Difference, Φ depends upon the reactive value of the components being used and hopefully by now we know that reactance, ( X ) is zero if the circuit element is resistive, positive if the circuit element is inductive and negative if it is capacitive thus giving their resulting impedances as:
Element Impedance
Circuit Element Resistance, (R) Reactance, (X) Impedance, (Z)
Resistor R 0 Resistance Expression
Inductor 0 ωL Inductance Expression
Capacitor 0 reactance of a capacitive Capacitance Expression
Instead of analysing each passive element separately, we can combine all three together into a series RLC circuit. The analysis of a series RLC circuit is the same as that for the dual series RL and RC circuits we looked at previously, except this time we need to take into account the magnitudes of both XL and XC to find the overall circuit reactance. Series RLC circuits are classed as second-order circuits because they contain two energy storage elements, an inductance L and a capacitance C. Consider the RLC circuit below.