What are the disadvantages of low power factor?
Low power factor is a measure of how efficiently an AC circuit uses the supplied power.
A low power factor means that the circuit draws more current than it needs to perform the same amount of work. This can have several disadvantages, such as:- Higher line losses: The higher current causes more heat to be generated in the conductors, which reduces the efficiency of the system and increases the cost of electricity.
The line losses are proportional to the square of the current, so a small decrease in power factor can cause a significant increase in losses¹.- Larger equipment size and cost: The higher current also means that the electrical equipment, such as transformers, generators, switchgears, etc., need to have a larger capacity and size to handle the load.
This increases the capital and maintenance cost of the equipment².- Poor voltage regulation and large voltage drop: The higher current also causes a larger voltage drop across the circuit, which reduces the voltage available at the load.
This can affect the performance and lifespan of the appliances and devices connected to the circuit. The voltage regulation is also affected by the phase difference between the voltage and current waves, which is related to the power factor².
– Low efficiency: All of the above factors result in a lower efficiency of the system, which means that more power is wasted and less power is delivered to the load. This can have economic and environmental impacts².
The main cause of low power factor is the use of inductive loads, such as motors, transformers, lamps, and welding equipment, which create a lagging power factor.
This means that the current wave lags behind the voltage wave by a certain angle. To improve the power factor, capacitive loads can be added to the circuit, which create a leading power factor.
This means that the current wave leads ahead of the voltage wave by a certain angle. By adding capacitors in parallel with the inductive loads, the phase difference between the voltage and current waves can be reduced or eliminated, which increases the power factor¹.
I hope this answer helps you understand the disadvantages of low power factor and how to improve it.