Why need Power Capacitor?
---Basic of Power Factor Correction （PFC）
Under normal operating conditions certain electrical loads ( e.g. induction motors, welding equipment, arc furnaces and fluorescent lighting) draw not only active power from the grid, but also inductive reactive power {kVar}. This reactive power is necessary for the equipment to operate correctly but could be interpreted as an undesirable burden on the grid. The power factor of a load is defined as the ratio of active power to apparent power, i.e. kW:kVA and is referred to as cosφ. The closer cosφ is to unity, the less reactive power is drawn from the grid. For systems with a lower power factor the transmission of electric power, the higher expenses both for supply distribution companies and the consumer.
This is the main reason why Electricity Supply Companies demand reduction of the reactive load in their networks via improvement of the power factor. In most cased, here have the economic punishment for poor power factor.
A capacitive reactive power resulting from the connection of a correctly sized capacitor can compensate for the inductive reactive power required by the electrical load. This ensures a reduction in the reactive power drawn from the supply and is called Power Factor Correction.
■ Rated Voltage ：250VAC、400VAC、450VAC、525VAC、690VAC、750VAC
■ Rated Power：5~40Kvar
■ Power Tolerance：0-+10%
■ Loss Tangent：<0.10%
■ Test Voltage between Terminals：1.75xUn/10s
■ Test Voltage between Terminals and Case: 3KV/10s
■ Insulation between Terminal and case:500V/60s, >100MΩ
■ Max RMS Voltage Rating: 1.1xUn
■ Max RMS Current Rating: 1.3xIn
■ Discharge：Will be discharged to 50V or less with 1 minute (Standard IEC 60831 requires a discharge to 75V or less within 3 minutes).
DNEC power capacitors produced in strict accordance with both China. National Standard GB12747.1-2004 and International Standard IEC931-1(1988) with the international most advanced metal deposit polypropylene film, production processing, technology and equipment. Environment friendly vegetable oil filled, keep DNEC with competitive price and quality. Widely used in low voltage power network to improve power factor, reduce reactive power wastage and improve energy quality.
DNSC capacitor produced with corrugated cutting technology which can solve the contact problem between the sprayed layer and the metalized film caused by the metal film contraction. Meanwhile, using the corrugated cutting technology can increase the contact area between sprayed layer and metal film, and make the capacitor anti-impact ability greatly improved. Good performance at heat dissipating and environmental protection with PU filled, skip the oil spills problem. Especially suitable for the high harmonics power system and the bad operating conditions.
DNECG is the pioneered power capacitor with the secondary protective structure in the world. Because of a number of advanced technologies, when the capacitor in over-temperature operation caused by harmonics, voltage and other factors, the secondary protective structure will output the control signal to cutoff the switch and start-up the over temperature protection, disabling the capacitor connected with grid until all indicators return to normal; when the capacitor over-voltage protection activated, it outputs the control signal to cutoff the switch at the same time cutting off the main circuit, keep the system in multiple protection. When the detuning compensation and tuning filter system consists of several parallel capacitors and reactor, all the secondary protection circuit can be in series, avoid a harmonic current amplification caused by only one or some capacitors failure make the system collapse. The occasional failure system will be forced to off until completed proper maintenance and prevent the expansion of the accident.
