Requirements documents for1. ProblemSince the beginning of power production, there has been concern about the efficiency of power transmission and distribution. There are two main issues that drive this concern. The first concern is economics while the second is power quality. If one can deliver power at a more efficient rate than his rival, then he will be chosen as the major power supplier simply because he can offer power at a less expensive price than his rival.Requirements documents forDesign of Power Capacitors for PowerFactor Improvement in a PowerDistribution Systemsubmitted to:Professor Joseph PiconeECE 4522: Senior Design IIDepartment of Electrical and Computer EngineeringMississippi State UniversityMississippi State, Mississippi 39762September 14, 2000submitted by:Page J. C., Parson L.B., Watson K.M., Wong C.S.Faculty Advisor: Dr. Stanislaw GryzbowskiDepartment of Electrical and Computer EngineeringMississippi State UniversityBox 9571Mississippi State, Mississippi 39762email: {jcp2, lbp1, kmw2, csw1}@ece.msstate.eduDEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERINGExecutive SummaryIn the power distribution industry today, utility companies are trying to come up with asolution to increase the efficiency of distributed power. One way of achieving this task is byimproving the power factor of a system by adding power factor correction capacitors. Powerfactor improvement is a very important aspect of power distribution. Without a good powerfactor, there cannot be an efficient means of transporting energy over long distances due to thelosses associated with moving power through a wire. This action has led to multiple studieson power factor correction. In order to achieve maximum efficiency, we had to increase ourpower factor as close to unity as possible. We accomplished this controlled boost of powerfactor by installing the proper number of specifically designed high voltage power capacitorsat the substation.In designing our capacitors, there were certain design constraints that had to be met andovercome. Our capacitors were designed according to established IEEE standard 18-1992. Inaddition, our capacitor bank was built around an average load on a typical substation. Thistypical substation is rated at 15kV and during the peak hours of the day, its load of 3MWdraws a total of 2MVAR of reactive power. Using these typical specifications, a bank of forty(40) capacitors was designed with each capacitor contributing 50kVAR of reactive power.These forty (40) capacitors were also economically feasible. Another constraint that had to beovercome was the capacitors' exposure to environmental conditions. Our capacitors are ableto withstand a corrosive environment and a wide variety of weather conditions such asextreme temperatures and lightning. Upon meeting all of the design constraints, our capacitorshave long lifetime expectancy.In overcoming the design constraints, several techniques have been incorporated. Weresearched the problem thoroughly and took into account the design parameters. We contactedseveral manufactures to learn about the construction of capacitors. Certain calculations wereperformed to determine the dimensions and the physical construction of the capacitor. Next,we used simulation tools (SuperHarm, Excel, and PSpice) to prove our design were feasible.After these appropriate simulations were conducted, we tested the model capacitors inMississippi State University's High Voltage Laboratory in order to verify their designfunctions and performance. We compared our test results with our design constraints and ourgoals were met.Due to the fact that using capacitors to correct a power factor has been around for many years,we are not the first to design and build a high voltage power capacitor. However, theinnovativeness of our project comes into play when one considers the careful insulationprocess and materials used to extend the capacitors’ life and efficiency.The future of capacitor design to correct power factor will be based on finding new materialsthat provide better insulation between the foil sheets. Today, researchers are trying to employnew high-tech polymer as the dielectric in capacitors. This will allow for higher voltages andsmaller physical dimensions of the capacitor to be attained.1. ProblemSince the beginning of power production, there has been concern about the efficiency of powertransmission and distribution. There are two main issues that drive this concern. The firstconcern is economics while the second is power quality. If one can deliver power at a moreefficient rate than his rival, then he will be chosen as the major power supplier simply because hecan offer power at a less expensive price than his rival.In order to offer power at a premium price, one has to minimize his losses associated withsending energy through a wire. To minimize the losses incurred when transmitting power, theoverall power system must be made more efficient by minimizing the voltage drop between thegenerator and the substation, and decreasing the current present on the power lines. The way toaccomplish this task is by addressing what is known as power factor correction. The power factorof a system is the ratio of the real power (generated by the "power-producing-current") to theapparent power (total current present). It expresses how efficiently the AC electrical power istransmitted and overall used. Inefficiency in a power system translates to wasted power, and aswith any type of business, a utility company certainly does not like to waste its product.In an energy system, the majority of electrical loads are inductive loads such as induction motors.These types of loads produce electromagnetic fields in order to operate. Inductive loads drawtwo kinds of power from the utility system: real and reactive. The real or active power is thepower that actually performs the work of creating motion, light, or heat while reactive powerproduces the electromagnetic fields necessary for the operation of induction motors. The realpower is measured in kilowatts (kW) and the reactive power is measured in kilovolt-ampere-reactive (kVAR). These two types of power are combined to make up apparent power, which isthe product of the voltage and current magnitudes; hence, it is measured in kilovolt-amperes(kVA). If
View Full Document
Unlocking...