What is mean by Inductor and Capacitor?

Inductor and Capacitor are the passive elements. This means that they consume energy from different power sources.

An inductor is also called a reactor (or) coil. Inductor is characterized by its inductance, which is the ratio of the voltage to the rate of change of current.  

and it is a passive two terminal component when current flows through it, it stores energy in the form of magnetic field.

Types of Inductors

  • Air-core Inductors
  • Iron core Inductors
  • Toroidal Inductors
  • Laminated Core Inductors
  • Powdered Iron Core Inductors


Inductance, Capacitance, Resistance and Conductance are Transmission line parameters. Inductance of transmission line is calculated as flux per ampere.

Induction motors, chokes, sensors are based on self-inductance. Mutual inductance is the basic principle of the transformer, motor, generators. The main objective of the transmission is to maximize power transfer to the transmission line and to the minimum voltage drop across the line. So by reducing the transmission line inductance, power transferred to the line can be increased.

To achieve low inductance, we have different arrangements :

  • Single phase 2wire
  • Three phase horizontal triangular
  • Bundle 
  • Double circuit transmission line configuration

Shunt and Series reactors

Shunt reactors are used in high voltage power transmission systems to stabilize the voltage during load variations. Shunt reactor is an absorber of reactive power thus increasing the energy efficiency of the system. Shunt reactors may be designed without air or iron core to prevent hysteresis loss.

During off-peak load period(night times) over voltage will occur called Ferranti effect which will damage the insulation. To protect the system equipment from this, shunt reactors(Inductors) are placed at the ends of 220,400,760KV substations and transmission lines. Why we are using these shunt reactors are mainly to limit the overvoltages and the second most is to limit the transfer of reactive power in the network.

Series reactor is connected in series with components to reduce the fault current magnitude. You should never connect a series reactor in series with a transmission line because it reduces the normal power flow. Series reactors are used as current limiting reactors to increase the impedance of a system. These are also used to limit the starting currents of synchronous electric motors.

Different types of series reactors

  • Generator reactors
  • Feeder reactors
  • Busbar reactors


A Capacitor is a device that stores energy in the form of an electrical field when current flows through it. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance.

Types of Capacitors

  • Ceramic capacitors
  • Film capacitors
  • Electrolytic capacitors
  • Super capacitors
  • Class X and Y capacitors
  • Miscellaneous capacitors
  • Variable capacitors


Capacitance is the ability of a body to hold an electrical charge. It is the ratio of the amount of electric charge stored on a conductor to a difference in electrical potential. There are two closely related notions of capacitance, they are self capacitance and mutual capacitance. Any object that can be electrically charged exhibits self capacitance. Mutual capacitance is intentional or unintentional capacitance that occurs between two charge-holding conductors, in which the current passes through one passes over into the other.

Shunt and Series capacitors

A capacitor connected in parallel to a load is a shunt capacitor. Shunt capacitors are extremely used in power systems across the load or on supply lines to offer leading load. 

These are the basic electrical terms to understand the technology.


  • Power factor of the system is improved.
  • Voltage regulation of the line is reduced.
  • Better voltage profiles.
  • Power transfer capacity is improved
  • System stability is improved

When capacitors are connected, one after another is a series of capacitor. 


  • Compensate the inductance of the transmission line.
  • Share the load between parallel lines.
  • Transmission capacity increases.
  • Stability increases.