Vikrant H. Chhapekar
Department of M.Tech (VLSI Design)
Jhulelal Institute of Technology, Lonara, Nagpur (INDIA)
Dr. Pramod Patil
Jhulelal Institute of Technology, Lonara, Nagpur (INDIA)
With the continuous rise in the demand and cost of energy, increased power efficiency and quality is very desirable. Power quality can be fairly increased through Power Factor Correction (PFC). In this paper aims to build a simple, compact and energy-efficient system for automatic power factor monitoring and control. This proposed solution based on ARM -Cortex. The use of ARM based 32-bit microcontroller promises for complete power management unit. Apart from lower power consumption, it allows easy extension of functionalities from power data logging, remote monitoring and control, emergency alarm etc.
Keywords – Efficient Electricity Management System Using Power Factor Correction, PFC ARM Cortex.
As we see that electricity is playing most important role everywhere like industries, home appliances are utilised more power but electricity is limited sources so we have to utilise it wisely. Due to this limited source we have to face many problems so we need to find some solution so we can avoid electricity scarcity problem. This paper proposed a solution which can be solve the problem electricity using Power Factor Correction (PFC). Power factor is playing very vital role in electricity distribution and utilisation process. A compact and efficient system for power factor control and power management can be very useful in industries with high inductive loads. Its use can be extended to within a building or a single machine or appliances. Embedded technology is one of the biggest boons to mankind. Its use greatly reduces Man power, saves time and space. Moreover, it increases efficiency without human interference and can incorporate built-in intelligence. Power Factor is defined as the ratio of the real power delivered to the load to the apparent power. It is a direct measure of the power quality. In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. The higher currents increase the energy lost in the distribution system, and require larger wires and other equipment. Because of the costs of larger equipment and wasted energy, electrical utilities usually charge a higher cost to industrial or commercial customers where there is a low power factor. Poor power factor costs our community in increased electricity charges and unnecessary greenhouse gases. While some countries provide incentives for customers to maintain the required power factor, some impose penalties for power factor dropping beyond a limit. Thus, power factor control is a vital part of efficient power management.
II. TECHNICAL BAGROUND
The power factor correction is necessary using power factor correction we can improve the system efficiency and also increased power handling capacity.
A. What is Power Factor
Power factor is the ratio of Active Power (KW) to Apparent Power (KVA). Where, KW is Working Power or Active Power or Real Power, Reactive Power is KVAR and KVA is Apparent Power. It is the “vectorial summation” of KVAR and KW.
B. Dragging Mac’s Analogy
Let us understand What Causes Low Power Factor why should we improve power factor in detail. Take an example of Dragging Mac’s BMI Analogy (Figure 1). Here we can see that Mac dragging a heavy load in forward direction lets Mac working power is KW. But his shoulder height adds little Reactive Power i.e. KVAR. Apparent power of Mac dragging load is vectorial summation of KW & KVAR. From the Dragging Mac’s BMI Analogy a Power Triangle is formed.
Above power triangle represent what is power factor cosine θ
of power factor correction.
The main objective of this project to power factor correction by reducing the effect of reactive power in apparent power.
A. Causes of Low Power Factor
Power Triangle shows the power factor cosine θ, so the lowering power factor is due to Reactive power KVAR. KVAR increases the amount of apparent power (KVA) in your distribution system. As increase in reactive and apparent power results in a larger angle θ, as θ increases, cosine θ (or power factor) decreases.
B. Necessity to Improve Power Factor
By lowering the utility bill by reducing peak KW billing demand & eliminating the power factor penalty, in your electricity system if you want to increase in system capacity and reduced system losses power factor must improve. Increase voltage level in your electrical system and cooler, more efficient motor.
C. Way to Improve Power Factor
The main reason for lower power factor is Sources of Reactive Power (inductive loads) like Transformer, Induction motors, Induction, generators (wind mill generators), High intensity discharge (HID) and lighting. Thus for the Power Factor Correction we have to add Capacitors in to the system and improve lowering power factor. By adding equal and opposite effect of capacitor (capacitive reactance) in against of inductive effect (inductive reactance) so both the effect cancel each other. The effect of reactive power get reduces and hence power factor get improve.
The power factor correction its proposed block diagram as shown in figure 2 below. As we can see in block diagram the heart is ARM-cortex which performs the complete operation switching, monitoring, calculation etc. The power factor meter is present which giving continues data of how much power factor lowered to ARM. A set of relays are present which switches the capacitors according to instructions of ARM. Capacitor bank which provide for reduce in reactive power which is applied to a load in parallel. Monitor displays the current, voltage, energy, power factor etc.
As we see in figure 2 the 230V AC supply going towards load through Power Factor Meter. Due to Reactive Power (KVAR) in load the power factor get lower, this information fed to ARM by Power Factor Meter. ARM first display the information about power factor on monitor. ARM calibrates the desire power factor by using Capacitor Bank. ARM is giving instruction to Relay Circuit, relay switches the capacitor which connected to the load and it can compensate the reactive power in the load. So these capacitors help to improve the lowering power factor of the system successfully.
The power factor correction it can be used in real time application in industries home appliances anywhere because mostly electrical parts contains inductive loads so there is chances of reduction in power factor . So improvement is necessary for effective utilisation of electricity without losses we have to use this method.
As we see in this proposed solution what are the necessities and causes of power factor reduction, so power factor have to improve because it directly affects system efficiency. Power factor correction drives the system efficiently with low losses and hence its better solution in cost wise. Furthermore we are trying to make this solution more accuracy and compact user friendly.
I would like to express sincere gratitude and appreciation to all those who gave me the possibility to complete this paper. A special thanks to my Project Guide Dr. (Mr.) Pramod Patil, Whose help, stimulating suggestions and encouragement, helped to coordinate project especially in writing this paper. Words often fail to pay one’s gratitude oneself, still we would like to convey sincere thanks to our H.O.D Prof. (Mr.) Sanjeev Sharma , without whose encouragement and guidance this project would not have materialized.
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