Short Answer:

Power factor in an electrical system can be improved by reducing the effect of inductive loads that cause lagging current. This is usually done by adding devices that supply leading reactive power to balance the circuit.

The most common way to improve power factor is by installing capacitors in the system. Other methods include using synchronous condensers and power factor correction devices like APFC panels. Improving power factor helps reduce energy loss, improve voltage stability, and lower electricity bills in industries and buildings.

Detailed Explanation:

Power Factor Improvement in Electrical System

Power factor is the ratio of real power to apparent power in an electrical system. A low power factor indicates that a significant amount of power is being wasted as reactive power, especially due to inductive loads like motors, fans, and transformers. Improving power factor means making sure that most of the supplied power is being used effectively for useful work.

Methods to Improve Power Factor

1. Capacitor Banks
   • Capacitors produce leading reactive power, which cancels out the lagging reactive power caused by inductive loads.
   • These are the most widely used and cost-effective solutions.
   • Can be fixed or automatic (switched based on load changes).
   • Installed in homes, commercial buildings, and especially in industries.
2. Synchronous Condensers
   • These are synchronous motors running without mechanical load.
   • They generate reactive power as needed and help correct the power factor dynamically.
   • Suitable for large power systems or grid applications.
   • Provide smooth voltage regulation and stability.
3. Automatic Power Factor Correction (APFC) Panels
   • These panels automatically monitor the power factor and switch capacitor banks on or off accordingly.
   • Ideal for systems where loads vary frequently.
   • Ensures consistent power factor correction and improved efficiency.
   • Used in factories, malls, and offices.
4. Use of Phase Advancers
   • Used mainly with large induction motors.
   • These devices are installed on the rotor side and improve the power factor by reducing lagging current.
   • More suitable for motors above 200 HP.
5. Reducing Idle Running of Motors
   • Turning off or disconnecting motors or machines when not in use helps in maintaining a better power factor.
   • Unused inductive loads still consume reactive power and lower the system power factor.
6. Efficient Load Management
   • Avoiding overloading or underloading of equipment helps maintain the system’s performance.
   • Operating machines near their rated capacity improves efficiency and power factor.

Benefits of Improving Power Factor

• Reduced energy losses in cables and transformers.
• Lower electricity bills, as many utilities charge penalties for low power factor.
• Improved voltage regulation and system stability.
• Increased system capacity by reducing unnecessary reactive current.
• Better lifespan for electrical devices due to reduced heating.

Example:

If a factory has a power factor of 0.7 and installs capacitor banks to bring it to 0.95, the energy losses decrease significantly, equipment operates more efficiently, and monthly electricity costs are reduced.

Conclusion:

Improving power factor in an electrical system involves compensating for the reactive power caused by inductive loads. The most effective way to do this is by using capacitors, synchronous condensers, or APFC panels. These methods help in reducing energy losses, improving voltage levels, and avoiding penalties from electricity providers. A good power factor ensures efficient, safe, and economical operation of electrical systems.