There is always a significant charging current flowing from conductor to earth in underground high voltage and medium voltage power network. This is because of dielectric insulation between earth and conductor in the underground cables. During an earth fault in any phase, in a 3 phase such system, the charging current of the system ideally becomes three times more than rated charging current per phase. This larger charging current restrikes and passes to ground through faulty point and causing a

The following two factors to be considered during measurement of reactance of a shunt reactor. The reactance of a shunt reactor is approximately equal to its impedance as the resistive component of the impedance in shunt reactor is negligible. The V-I characteristics of the shunt reactor is almost linear under operating range of appliedvoltage. This is because, gapped core is used in the shunt reactor to preventmagnetic saturationof the core within normal operational range.The simple formula of

Shunt Reactor is used to compensate capacitive reactive power of a long transmission line. The constructional features of a shunt reactor may vary manufacturer to manufacturer but basic of construction is more or less same.Core of Shunt ReactorGapped Core is generally used in shunt reactor. The core is constructed from Cold Rolled Grain Oriented Silicon Steel sheet to reduce hysteresis losses. The sheets are laminated to reduce eddy current losses. Gaps are intentionally provided in the construc

What is a Line Reactor?A line reactor (also referred to as an electrical reactor or a choke) is a variable frequency drive (VFD) accessory that consists of a coil of wire that forms a magnetic field as current flows through it. This magnetic field limits the rate of rising of the current, thus reducing harmonics and protecting the drive from power system surges and transients.Types of Electrical or Line ReactorsA reactor has many roles to play in an electrical power system. The reactors are norm

A shunt reactor is defined as a device that absorbs reactive power from a power system and helps regulate the voltage level. Shunt reactors are typically used in high-voltage transmission lines and substations to compensate for the capacitive effect of long cables and overhead lines. Shunt reactors can be either fixed or variable, depending on the degree of voltage regulation required.Shunt reactors are essential for maintaining the stability and efficiency of power systems, especially in long-d

It is not always economical to keep a capacitor bank in service throughout the day and night. This is because, a capacitor also provides reactive power to the system as inductor but in opposite direction. Actually capacitive reactive power provided by capacitor neutralizer the inductive reactive power generated in the system due to inductive load. In this way overall reactive power of the system is reduced hence power factor of the system is improved as result voltage profile of the system is im

ANSI, IEEE, NEMA or IEC standard is used for testing a power capacitor bank.There are three types of test performed on capacitor banks. They are Design Tests or Type Tests. Production Test or Routine Tests. Field Tests or Pre commissioning Tests.Design Tests or Type Tests of Capacitor BankWhen a new design of power capacitor is launched by a manufacturer, it to be tested whether the new batch of capacitor comply the standard or not. Design tests or type tests are not performed on individual capa

The power factor improver capacitor can be installed at system bus, distribution point and at load itself. But decision should be taken in view of expenditure and utility.In certain loads mainly in industrial load, the entire load is switch ON or OFF based on need. In such cases it is recommended to install capacitor bank with the feeder which provides entire of this particular load. This scheme is known as branch capacitor bank scheme. As capacitor bank is directly connected to feeder or branch

Unit of a capacitor bank is normally called capacitor unit. The capacitor units are manufactured as single phase unit. These single phase units are connected in star or delta to farm a complete 3 phase capacitor bank. Although some rare manufacturers 3 phase capacitor unit but normally available capacitor units are single phase type. The Externally fused capacitor bank. Internally fused capacitor bank. Fuse less capacitor bank.Let us discuss these types of capacitor bank one by one.Externally Fu

A capacitor bank has to go through different abnormal system conditions, during its life span. To with stand these abnormalities at optimum manufacturing cost, the capacitor banks are rated with following allowable parameters. A capacitor bank should continue its service with in the following limits. 110 % of normal system peak voltage. 120 % of normal system rms voltage. 135 % of rated KVAR. 180 % of normal rated rms current.Voltage Rating of Capacitor BankA capacitor unit is normally designed