Capacitor  Bank

The demand for active power is expressing weight unit Watt (kW) or megawatt (MW). This power ought to be provided from the electrical generating station. All the arrangements in electrical pomes system square measure done to fulfil up this basic demand. though in the alternating power grid, reactive power perpetually comes into image. This reactive power is expressed in weight unit volt-ampere or Mega volt-ampere.
The demand for this reactive power is principally originated from an inductive load connected to the system. These inductive hundreds square measure usually magnetism circuit of electrical motors, electrical transformers, the inductance of transmission and distribution networks, induction furnaces, fluorescent lightings etc. This reactive power ought to be properly paid otherwise, the quantitative relation of actual power consumed by the load, to the overall power i.e. resultant of active and reactive power, of the system becomes quite less.
This quantitative relation is as an alternative referred to as electric power issue, and fewer ratios indicate poor power issue of the system. If the ability issue of the system is poor, the ampere burden of the transmission, distribution network, transformers, alternators and different types of equipment connected to the system, becomes high for needed active power. And thus reactive power compensation becomes thus vital. this can be usually done by condenser bank.
Let's make a case for in details,
                        we know that active power is expressed = vIcosθ
Where cosθ is that the power issue of the system. Hence, if this power issue possesses less valve, the corresponding current (I) will increase for same active power P.
As the current of the system will increase, the resistance unit loss of the system will increase. resistance unit loss suggests that generated electric power is lost as unwanted heat originated within the system. The crosswise of the conducting elements of the system may additionally have to be compelled to be raised for carrying further ampere burden, that is additionally not economical within the industrial purpose of reading. Another major disadvantage is poor voltage regulation of the system, that chiefly caused because of poor power issue.
The equipment accustomed compensate reactive power.
There square measure chiefly 2 types of equipment used for this purpose.

•  synchronous condensers
•  Static capacitors or condenser Bank

synchronous condensers will manufacture reactive power and therefore the production of reactive power may be regulated. because of this regulation advantage, the synchronous condensers square measure terribly appropriate for correcting power issue of the system, however, this instrumentation is kind of value compared to static capacitors. that's why synchronous condensers, square measure even to use just for voltage regulation of terribly high voltage gear. The regulation in static condensers may be achieved to some extent by split the overall capacitor bank in three sectors of quantitative relation one: two: two. This division permits the condenser to run in one, 2, 1 + 2 = 3, 2 + 2 = 4, one + two + two = five steps. If still any steps square measure needed, the division is also created within the quantitative relation one: two: three or one: two: four. These divisions create the static condenser bank dearer however still the price is far lower them synchronous condensers.
It is found that most get pleasure from compensating equipment may be achieved once they square measure connected to the individual load facet. this can be much and economically doable solely by victimization tiny rated capacitors with the individual load not by victimization synchronous condensers.

Static condenser Bank

Static condenser will any be divided into 2 classes,
(a) Shunt capacitors
(b) Series condenser
Series condenser BankShunt condenser Bank These classes square measure chiefly supported the ways of connecting condenser bank with the system. Among these 2 classes, shunt capacitors square measure a lot of usually employed in the ability system of all voltage levels. There square measure some specific blessings of victimization shunt capacitors like,
It reduces line current of the system.
It improves voltage level of the load.
It conjointly reduces system Losses.
It improves power issue of the supply current.
It reduces the load on the generator.
It reduces capital investment per megawatt of the Load.
All the on top of mentioned edges come back from the very fact, that the result of condenser reduces reactive current flowing through the total system.
Shunt condenser attracts the nearly fastened quantity of leading current that is superimposed on the load current and consequently reduces reactive parts of the load and thus improves the ability issue of the system.
series condenser on the opposite hand has no management over the flow of current. As these square measure connected asynchronous with load, the load current perpetually passes through the series condenser bank. Actually, the electrical phenomenon electrical phenomenon of series condenser neutralizes the inductive electrical phenomenon of the road thus, reduces, the effective electrical phenomenon of the road. Thereby, voltage regulation of the system is improved. however, series condenser bank features a major disadvantage. throughout faulty condition, the voltage across the condenser perhaps raised up to fifteen times quite its rated price. therefore series condenser should have subtle and elaborate protecting equipment. attributable to this, use of-series condenser is confined within the further high voltage system solely.

Shunt condenser
Construction of Shunt condenser

The active elements of condenser unit square measure composed of 2 atomic number 13 foils separated by inseminated papers. The thickness of the papers could vary from eight microns to twenty-four microns relying upon the voltage level of the system. The thickness of the aluminium foil is within the order of seven microns. For low voltage applications, there is also one layer of inseminated paper of appropriate thickness between the foils except for higher voltage applications quite one layer of inseminated papers square measure placed between the aluminium foil to avoid unwanted circulation of short current between the foil because of the presence of conducting matters within the papers.
The condenser sections square measure wound into rolls thenceforth they're planate out, compressed into packs, fencelike in multiple layers of significant paper insulations and inserted into the containers. once the lid had been welded to the instrumentation, the condenser unit is dried and integrated into giant autoclaves by a mixture of warmth and vacuum. once the paper is totally dried and every one gases off from the insulation the condenser tank is stuffed with impregnant degassed at identical vacuum.
In the early stages of development, it absolutely was usually mineral insulating oil that was used as impregnant. This has currently been replaced by most of the makers with artificial liquids of chlorinated diphenyl cluster bearing completely different trade names. Mineral insulating oil has terribly low electrical conduction and extremely high insulator strength. however it's but some drawbacks like,

• It has low insulator constant.
• The voltage distribution of the oil isn't uniform.
• It is terribly burnable.
• It is subjected to oxidization.

With the artificial impregnant, it's quite doable to manufacture smaller condenser unit with higher voltage rating. The voltage rating of the condenser unit is restricted at intervals bound limits as a result of on low voltage the price per weight unit volt-ampere goes high. for top voltage applications, numbers of condenser units square measure connected asynchronous and parallel combination to make a condenser bank for needed voltage and weight unit volt-ampere ratings. for instance once five.1 Mega volt-ampere condenser bank is to be commissioned in Associate in Nursing one kV system, every unit of the bank is formed of eleven kV rating. during this installation, per the part demand of Mega volt-ampere is five.1/3=1.7. during this installation, there ought to be just one condenser unit connected asynchronous and seventeen of such units square measure connected in parallel to fulfil up the mega volt-ampere demand of 1 part. 3|for 3} part system three such teams of condenser unit square measure connected along in star or delta kind. Let’s show another example of higher understanding. once a bank of five.4 Mega volt-ampere is to be put in at the thirty-three kV three-part system. There shall be 3 condenser units connected asynchronous and 6 of such series mixtures square measure connected in parallel to fulfil up one.8 The Mega volt-ampere demand of per part. identical condenser units may be used for 132 kV systems too. For that Series and parallel mixtures of the fundamental condenser units are going to be assembled as per mega volt-ampere demand.