Power Factor Correction
Power factor is the ratio of active power or real power to apparent power flowing in the circuit. The apparent power is the amount of power flowing toward the appliance or circuit and the active power is the power that it actually uses to perform a function. The energy that is of apparent power is known as reactive power. The value of power factor ranges between two values: -1 and 1. The value of power factor closer to 1 means that power is being transmitted in an efficient manner and there is very little loss of power as reactive power. The value of power factor closer to -1 means that a lot of power is coming back to the generator or power source, and is not useful in the form of reactive power.
In more simple words, a system with a high power factor uses less current as compared to a system with low power factor to perform the same function. Poor power factor results in the usage of higher current to perform the same amount of work, which results in not useful of power.
What is Power Factor Correction?
Reactive energy results in unnecessary costs that need to be minimized. Power factor correction is the broad term applied to correct an inadequate power factor correction and make power flow more efficient. Power factor correction reduces useless power and saves high electricity costs.The use of capacitors and inductors applies it. Inductive loads such as electrical motors, transformers, welding devices and many others usually have low power factors as the inductive current is necessary for the functioning of such systems. The capacitors have a general property to store current for short intervals of time.
Power factor correction involves converting a circuit where voltage and current are not in phase with each other to a circuit where the voltage and current are in phase with each other. Let’s say there is a circuit where an inductor is causing a displacement reactive power. The effect of that inductor causing the reactive power can be decreased or totally cancelled out by adding a capacitor to the circuit. Hence the inductive power caused by the inductor can be compensated by the capacitor. And the apparent power can be the same as the real power consumed by the circuit. So the power factor can be 1, thus making the flow of current more efficient.
- Active Power (kW) : Power that is performing useful work
- Reactive Power (kVAR) : Power that is not performing useful work
- Apparent Power (kVA): The vector sum of Active and Reactive Power.
- Power factor: The cosine of the angle between active and apparent power vectors
Power factor correction is applied through power factor correction equipment which contains capacitors.
The capacitors reduce the magnetizing current as much as possible, without affecting the proper functioning of the equipment. The static power correction is applied by connecting the correction capacitors to the starter motor. Static power correction has a drawback as it leads to over or under power correction in systems of variable speed. It can lead to significant damage to the equipment.
Why is Power Factor Correction Necessary?
In systems where the delivery of current is not efficient, a lot of current is wasted as reactive current. It leads to high electricity costs for wasted power. With power factor correction, the same amount of work can be done with significantly less electricity costs. The industrial units that operate at low power factors have high electricity costs, which make it difficult to operate in a competitive market. Many types of power factor correction solutions are available and are widely applied to minimize electricity costs.
Power Factor Correction Thanks to Capacitor Banks
Improving the power factor means reducing the phase difference between voltage and current. Most of the loads are inductive in nature and need some amount of reactive power to function properly.
Capacitors act as a local source of that reactive power needed by the inductive load and so less reactive power through the source runs into the circuit. So, capacitors decrease the phase difference between voltage and current.
Advantages of Power Factor Correction
Power factor correction has numerous advantages. Following are some advantages of power factor correction: Keep in mind that power companies provide incentives for maintaining the power factor above 0.9.
- Power companies also penalize consumers on having a poor power factor. For instance, penalties can be avoided by having power correction systems.
- Where Power Factor correction is applied, there is a lesser loss of power. And this means that there is extra kVA available from the existing supply.
- Power Factor correction can be very substantial for the environment. Power factor correction decreases the energy losses. And decreased energy losses means less greenhouse gas emissions and consumption of fossil fuels by the power generation stations.
- Power Factor correction leads to a significant decrease in electricity bills. The loss of power in the form of reactive current is decreased and the overall consumption of electricity is also decreased as the systems work more efficiently, and this leads to the reduction of electricity bills.
- Application of Power Factor correction leads to the extended life of electrical equipment such as cables. There is way less burden on cables and other electrical equipment.. Moreover, there is a reduction in voltage drop in long cables.
The Bottom Line
Power factor correction is widely applied technology in industry and complex electrical systems. Power factor correction leads to a reduction in cost of electricity which leads to reduced operating cost of a business, thus increasing profit. Power factor solutions should be applied to the electrical systems to ensure low electrical costs and more efficient working of electrical equipment.
FAQ About Power Factor Correction
How do you calculate power factor correction?
When calculating active power, active power is multiplied by Cosφ. For this reason, Cosφ is called the power factor. Power coefficient value, ie Cosφ value, must be kept between 0.95 and 1.
Why power factor correction is required?
Cosφ value must be kept between 0.95 and 1. Otherwise, if the Cosφ value is not in the range of 0.95-1, consumers must pay a penalty for the reactive energy or power they consume.
Does power factor correction save money?
Thanks to the correction of the power factor, the facilities are not subject to penalties first. Moreover, throughout the facility, productivity increases, electricity losses decrease, and the usage quality of products increases.
Why capacitor is used in power factor correction?
Loads in facilities generally generate inductive power. Especially high power loads such as electric motors increase the inductive value. Therefore, inductive power is balanced by using a capacitor.