IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE) e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 12, Issue 1 Ver. IV (Jan. – Feb. 2017), PP 30-34 www.iosrjournals.org DOI: 10.9790/1676-1201043034 www.iosrjournals.org 30 | Page Improvement of Load Power Factor by Using Capacitor Ahmad Yani 1 1 (Faculty of Electrical Engineering, STT-Harapan, Medan, Indonesia) Abstract: Series and parallel capacitors in the power system effect reactive power to improve power factor and voltage because of increasing the system capacity and reducing losses. Reactive power of series capacitor is the same to the current. There are certain unpleasant aspects in the capacitor series. Generally, the cost to install a series capacitor is higher than parallel capacitor. It is caused by complex protection equipment for series capacitor and designing series capacitors for greater power than parallel capacitor to solve the future cost. Installation of capacitors is important to reduce of a system reactive power. Transmission line would be most economical if it is used to send active power where the need of reactive power can be obtained by distribution system in substation level. This will allow user in optimum transmission line, improve operational performance and reduce energy losses. It requires a system and planning carefully to fulfill the need of system reactive power in the same way with active power planning and it is programmed an additional generator capacity. Keywords: Capacitor, parallel, factor, load. I. Introduction Before discussing about the improvement of power factor by using capacitor, we should recall the general knowledge of Apparent Power, Active Power and Reactive Power. In the electrical system Alternating Current (AC), there are three types of power that are well known, especially to the load impedance (Z) which are: - Apparent Power (S, VA, Volt Ampere), Active Power (P, W, Watt), Reactive Power (Q,VAR, Volt Ampere Reactive). For the AC power circuit, the voltage and current waveforms are sinusoidal, where the magnitudes of the power at any time are not same. Therefore, the average power is measured in Watts. This power had form active energy per unit in time and can be measured with Kwh meter and is also a real power or active power (shaft power, actual power) that used by the load to perform a specific task. While the apparent power expressed in Volt-Ampere units (VA), which is stated the capacity of electrical devices, as shown on the generator and transformer equipment. At some installations, particularly in the plant or industry there are also have specific loads such as electric motors, that is require other type of power, which is reactive power (VAR) to create a magnetic field or it means the reactive power is the power that is used as generation energy of magnetic flux until it caused magnetization and this power is restored to the system due to the effect of electromagnetic induction itself, so that the power is actually the load (demand) in the electrical energy system. Figure 1: Power Triangle II. Research Methodology 2.1 Definition of Power Factor / Work Factor Power factor or work factor is the comparison between active power (Watt) with apparent power / total power (VA), or cosine angle between active power and apparent power / total power (see Figure 1). The higher reactive power will increase this angle and as the result the power factor will be lower. Power factor is normally lower than or equal to one. Theoretically, if the entire load power that supplied by the electrical company has a unity power factor, so the maximum power transfer is equivalent to the distribution system capacity. Accordingly, with the induced load and if the load factor range from 0.2 to 0.5, then the capacity of the electricity distribution network becomes depressed. Thus, reactive power (VAR) should be as low as possible