The term Reactive Power Compensation Services and Study is described as the regulation and control of the reactive power to improve the performance of alternating current or AC. The problem of reactive power compensation is generally related to load and voltage support. The goals of load support are to increase the value of the system power factor, balance the real power drawn from the alternating current supply, improve voltage regulation, and eliminate current harmonic components produced by large and fluctuating nonlinear industrial loads. Voltage support is typically required to reduce voltage fluctuation at a transmission line terminal. By increasing the maximum active power that can be transmitted, reactive power compensation in transmission systems improves the stability of the ac system.
Because reactive power has a higher capacity than is actually required, it is best to generate reactive power only when it is needed. If the reactive power is generated by a power plant, all of the equipment associated with the distribution system must be aligned with it.
Reactive power is a necessary component of electric power systems. Without reactive power, rotation can’t be initiated in rotating machines and active power cannot be transmitted through transmission lines. There are numerous advantages to being able to control or compensate for reactive power. Positive and/or negative VArs are added or injected into the power system during the reactive power compensation process to achieve voltage control.
Reactive power is a necessary component of electric power systems. Without reactive power, rotation can’t be initiated in rotating machines and active power cannot be transmitted through transmission lines. There are numerous advantages to being able to control or compensate for reactive power. Positive and/or negative VArs are added or injected into the power system during the reactive power compensation process to achieve voltage control. Harmonic distortions in the power system were briefly discussed, as were the problems caused by non-linear loads. Power compensation study also addresses the issues with harmonic analysis of the system.
The Need of Reactive Power Compensation Services:
In resistive loads, the current generates heat energy, which results in the desired output, whereas in inductive loads, the current generates a magnetic field, which results in the desired work. As a result, reactive power is the non-working power generated by magnetic current in order to operate and sustain magnetism in the device.
Reactive power (vars) is necessary for keeping the voltage high enough to deliver active power (watts) via transmission lines. When there is insufficient reactive power, the voltage drops and it is impossible to deliver the required power to the load via the lines.
The reactive power generated by the alternating current power source is stored in a capacitor or a reactor for a quarter of a cycle before being returned to the power source in the next quarter of the cycle. As a result, the reactive power oscillates at twice the rated frequency between the alternating current source and the capacitor or reactor (50 or 60 Hz). To avoid circulation between the load and the source, it must be compensated. Reactive power must also be compensated in order to regulate the power factor of the system and maintain voltage stability. This is done by Reactive Power Compensation Services and studies.
Various Methods of Providing Reactive Power Compensation Service:
There are basically three methods through which reactive power compensation services are carried out. They are:
- Shunt compensation: Shunt-connected reactors are used to reduce line overvoltages by consuming reactive power, whereas through the use of shunt-connected capacitors, reactive power is compensated on transmission lines to maintain voltage levels. A shunt compensator is always connected in the transmission line’s centre and is connected in parallel with the transmission line. It can be powered by a current or voltage source, or by a capacitor. The reactive power in the system is supplied by an ideal shunt compensator.
- Series compensation: Reducing the transmission’s reactive impedance is achieved by using a series compensator line in order to reduce voltage drop over long distances and the Ferranti effect. It is linked to the transmission line in series. A series compensator can be attached to the line at any point. There are two modes of operation: capacitive operation and inductive operation. The magnitudes of the two buses’ voltages are assumed to be equal as V, and the phase angle between them is.
- Static VAR compensators : (or SVCs) are electrical devices used to provide reactive power on transmission networks. Static compensators, as the name says, do not show any movement in the system parts. The SVC is an automated impedance matching device that is intended to bring the system closer to a power factor of unity. If the reactive load of the power system is capacitive (leading), the SVC will use reactors (typically implemented in the form of thyristor-controlled reactors) to imbibe variables from the system, lowering system voltage.When the reactive load is inductive (lagging), the capacitor banks are automatically switched on, resulting in a higher system voltage.
Types of Reactive Power Compensation Services:
Capacitors are the most commonly and widely used solution for pF correction in Reactive Power Compensation Study globally, and the following power factor correction types are used based on the location of the capacitor.
Distributed power factor correction:
Capacitor banks are directly connected to the terminal of the load that requires reactive power in this type of power factor correction. This type of installation is both inexpensive and straightforward. The capacitor bank and the load can both use the same overcurrent protection device. Consequently, it can be both connected and disconnected simultaneously. This type of power factor correction is recommended for large loads that remain connected to the system for an extended period of time. Induction motors and fluorescent lamps are common applications for distributed power factor correction.
Group power factor correction:
This method is typically used for loads that perform similarly. To improve the power factor, a common capacitor bank is provided. For example, if you have three similar induction motors that are used for the same purpose, you can use a common capacitor bank for power factor correction. This method is also cost-effective, but it is only recommended for small loads.
Centralized power factor correction:
In some systems, not all loads are active all day. Only a few loads are started for a short period of time. The use of distributed power factor correction is not a good option in such cases. As a result, centralised power factor correction is preferable. In which capacitor banks are located at the system’s origin or centre. This allows for a significant reduction in the total power of the installed capacitors. The capacitor banks must be equipped with an active switch, as keeping the capacitor banks permanently connected to the system is not a good idea.
Combined power factor correction:
As the name implies, it is a hybrid of two methods: distributed power factor correction and centralised power factor correction. For the large load that runs continuously, distributed power factor correction is used in this method. A centralised power factor correction method is also used to improve the power factor of small equipment.
Automatic power factor correction:
Due to the obvious working cycle of the equipment, consistent absorption of reactive power does not occur in the majority of systems. These installations are equipped with automatic power factor correction systems. As a result, different capacitor banks can be switched on and off as needed. These automatic power factor control panels, also known as APFC panels, are widely used.
SASPPL has been conducting Reactive Power Compensation Service and Study impartially for over 2 decades now. In fact, it has worked with the Maharashtra State Electricity Distribution Company Limited (MSEDCL) to help them understand the impact of overcorrection in their system post with kVAh billing was implemented in the state of Maharashtra. Further SASPPL was instrumental in presenting the findings to the Maharashtra Electricity Regulatory Commission (MERC) and the same can be found mentioned in the MREC Tariff petition order of 2018.
If you want to reduce your distribution losses and optimize your Energy bills by maintaining pF please connect with SASPPL.