Basic Electrical and Electronics Engineering: Unit I: Electrical Circuits

RLC Series Circuit

Basic Circuit diagram, Phasor diagram, Formula with Solved Example Problems | Electrical Circuits

Apparent power, S = VI, Active power, P = VI cos ϕ, Reactive power, Q = VI sin ϕ

RLC SERIES CIRCUIT

Fig 1.35 shows the RLC series circuit


Where

R - Resistance in ohm

L - Inductance in H

C - Capacitance in F

V - Input voltage

I - Current through the circuit

VR - Voltage drop across R = IR

VL - Voltage drop across L = IXL

VC - Voltage drop across C = IX.

Impedance


Phasor diagram is shown in fig 1.36


Example: 17

A resistor of 20Ω, inductor of 0.2 H and a capacitor of 150 µF are connected in series and fed by a 230 V, 50 Hz, AC supply. Find (i) XL (ii) XC (iii) Impedance (iv) Current (v) Power factor (vi) Apparent power (vii) Active power (Viii) Reactive power.

XL = 2πƒL = 2 × π × 50 × 0.2

= 62.83 Ω


= 21.22 Ω


= 46.16 Ω

Current I = V/Z

= 230/46.16

= 4.98 A

Power factor, cos ϕ = R/Z

= 20/46.16

= 0.433

Apparent power, S

VI = 230 × 4.98

= 1145.4 VA

Active power, P

P = VI cos ϕ

= 230 × 4.98 × 0.433

= 495.95 W

Reactive power, Q

Q = VI sin ϕ

= 230 × 4.98 × 0.901

= 1032 VAR

Basic Electrical and Electronics Engineering: Unit I: Electrical Circuits : Tag: : Basic Circuit diagram, Phasor diagram, Formula with Solved Example Problems | Electrical Circuits - RLC Series Circuit