The majority of the time, alternating current (AC) is used to generate, transfer, distribute, and use electrical energy (AC). However, has a number of clear drawbacks. One of these is the requirement for reactive power to be supplied in addition to active power. either lagging or leading. Reactive power does not contribute to the energy consumed or transferred; instead, it is the active power that does so. The term “total power” includes reactive power as a natural component.

Almost every system component, including generation, transmission, and distribution as well as loads eventually, generates or consumes reactive power. Resistance and reactance are the two elements that make up the impedance of a branch of a circuit in an AC system. It can be either inductive or capacitive, which adds to the circuit’s reactive power.

Reactive power is a necessary component of electric power systems. Both the initial rotation of spinning machinery and the transmission of active power through transmission lines require reactive power. There are various advantages to being able to control or compensate for reactive power. Positive and/or negative VArs are added to or injected into the power system during the reactive power adjustment process in order to change the voltage.

The majority of the loads are inductive and require lagging reactive power to be provided. In the distribution system, it is more cost-effective to supply this reactive power close to the load. Shunt or series Reactive power compensation is an option in power systems.

What is the need for Reactive Power Compensation?

In contrast to resistive loads, where the current produces heat energy, inductive loads use a magnetic field created by the current to accomplish the required work. Reactive power, or non-working power, is produced by magnetic current in order to operate and retain magnetism in the apparatus.

Reactive power (vars) is necessary to maintain a high enough voltage to transmit active power (watts) through transmission lines. When there is not enough reactive power, the voltage drops and it is no longer able to use the lines to supply the load with the required power.

Reactive energy generated by an alternating current power source is stored in a capacitor or reactor for a quarter of a cycle before being released back into the power source in the subsequent quarter. As a result, the reactive power oscillates at twice the rated frequency between the capacitor or reactor and the alternating current source (50 or 60 Hz). To avoid circulation between the load and the source, it must be balanced. Reactive power needs to be rectified as well in order to maintain voltage stability and control the system’s power factor. To do this, Reactive Power Compensation Services and research are used.

In general, there are three approaches to offering reactive power compensation services:

1. Shunt compensation: Reactors are used to reduce line overvoltages by consuming reactive power, whereas shunt-connected capacitors are used to compensate for reactive power to maintain voltage levels on transmission lines. Transmission lines run parallel to shunt compensators, which are always connected in the middle of the line. A capacitor, a source of current, or a source of voltage could power it. The reactive parts of the system are driven by an ideal shunt compensator.
2. Series compensation: By using a series compensator line, the reactive impedance of the transmission is decreased in order to reduce voltage drop over long distances and the Ferranti effect. It is connected to the transmission line through a number of points. A series compensator can be connected to the line at any point. The two available modes are capacitive operation and inductive operation. Both the two buses’ respective voltage magnitudes and their phase angle are assumed to be and, respectively.
3. Static VAR compensators: Static VAR compensators, sometimes referred to as SVCs, are electrical devices that are used to deliver reactive power on transmission networks. Static compensators, as their name suggests, do not allow any movement in the system’s individual parts. To increase the power factor of the system, the SVC, an automatic impedance matching tool, is employed. If the reactive load of the power system is capacitive, the SVC employs reactors—typically implemented as thyristor-controlled reactors—to assimilate system variables and reduce system voltage (leading). When the reactive load is inductive (lagging), the capacitor banks automatically turn on, increasing the system voltage.

What are the Reactive Power Compensation Services?

Because capacitors are the most common and commonly used solution for pF correction in reactive power compensation studies globally, the following power factor correction types are used based on where the capacitor is positioned.

Distributed power factor correction:

In this type of power factor correction, the terminal of the load that requires reactive power is directly connected to the capacitor bank. This installation method is easy and reasonably priced. Both the load and the capacitor bank can be protected from overcurrents by the same device. It can therefore be both connected and disconnected at once. It is recommended to utilize this type of power factor adjustment for large loads that are connected to the system for an extended period of time.

Power factor correction for groups of loads is a common practice for loads with comparable performance. The power factor can be improved by using a shared capacitor bank. For instance, if you have three identical induction motors used for the same purpose, you can use a shared capacitor bank for power factor modification. This method is only suggested for light loads while being comparably economical.

Centralized Power Factor Correction:

Not all loads in every system are constantly active. For a short period of time, only a few loads are started. Utilizing distributed power factor correction under these conditions is not a sensible choice. Therefore, centralized power factor correction is preferred. This sets the capacitor banks of the system’s origin or center there. This makes it possible to drastically reduce the overall power of the installed capacitors. Because it is not a good idea to keep the capacitor banks continuously connected to the system, they must have an active switch.

As the name implies, combined power factor correction is a technique that combines distributed and central power factor correction. The massive load that runs continuously is corrected by using distributed power factor. A centralized power factor correction method is also used to improve the power factor of tiny equipment.

Automatic Power Factor Correction:

Because of the equipment’s evident working cycle, most systems do not consistently absorb reactive power. Power factor adjustment mechanisms are automatic in these settings. As a result, different capacitor banks can be turn on and off as needed. These automatic power factor control panels, often known as APFC panels, are frequently used.

Conclusion:

Overall, it is clear from the foregoing explanation that reactive power compensation is essential for enhancing the effectiveness of the ac system. Reactive power compensation allows us to regulate the power factor and lower energy usage.

SASPPL has carried out objective Reactive Power Compensation Service and Study for more than 20 years. In fact, it has worked with the Maharashtra State Electricity Distribution Company Limited (MSEDCL) to help them comprehend the implications of overcorrection in their system after the introduction of kVAh billing in the Maharashtra state. The 2018 MREC Tariff Petition Order further mentions that SASPPL was instrumental in presenting the findings to the Maharashtra Electricity Regulatory Commission (MERC).