power systems loss

What are the factors considered in understanding the operating principles of a watt-hour meter? GENERAL. For the sake of simplicity, the discussion in this section will be mainly based on a single-element (singlephase) meter. Two- and three-element meters are simply two or three single elements having a common shaft and register, which serve to totalize the energy measured by each element.

What are the common constants used in electricity metering? The following definitions of various meter constants are taken from the Code for Electricity Metering, 6th edition, ANSI C12. Register constant Kr – is the factor by which the register reading must be multiplied in order to provide proper consideration of the register or gear ratio and of the instrument-transformer ratios to obtain the registration in the desired units.

What are the common causes of errors in watt-hour metering? The following ranges, based on reclamation standard, should be the main basis in which the meters should be adjusted. Meter accuracy is very important in watt-hour meter since these meters should be a precise instrument that should capable of adjusting within very close limits and with regular servicing maintaining its accuracy indefinitely;

POWER MEASUREMENT ACCURACY IN WATTMETERS Some factors considered in wattmeter accuracy equipment? Electronic wattmeter of 0.1% or better accuracy may be based on a pulse-area principle. Voltages proportional to the applied voltage and to the current (derived from resistors or transformers) govern the height and width of a rectangular pulse so that the area is proportional to the instantaneous power. This is repeated many times during a cycle, and its average represents active power. Average power also can be measured by a system which samples instantaneous voltage and current repeatedly, predetermined intervals within a cycle. Laboratory-standard wattmeters use an electro-dynamic mechanism and are in the 0.1% accuracy class for dc and for ac up to 133Hz. This accuracy can be maintained up to 1 kHz or more. Such instruments are shielded from the effects of external magnetic fields by enclosing the coil system in a laminated iron cylinder. Instruments having current ranges to 10A and

Continuation of the types of meter related problems which causes power loss. Misrecorded Meter Multipliers One serious problem that sometimes occurs on metering and billing systems is that the meter multiplier is not properly recorded by the billing system. For example, if the correct multiplier is 120 and the billing system has it recorded as 80, both demand and energy billings for the involved consumer will be only two-thirds of the correct amount. Furthermore, this error will not be a one-time occurrence, but will persist month after month, year after year.

What are the different types of electric meters related problems that contributes to power losses? Defective Meters Although electric meters are hardy devices, it is always possible that some of them may develop defects over extended service periods. To ensure that meters on the system will remain accurate, the distributor should implement a periodic meter testing program. Periodic meter testing is required by TVA although testing intervals are not specified. A program meeting current industry standards should be designed so each meter on the system is tested no less frequently than shown in table.

What are the different types of electric meters related power losses? Besides losses found in the power system namely; transmission line loss, substation transformer loss, distribution line loss, distribution transformer loss, secondary line loss, and other electrical device losses, another part in an electric utility where power losses usually occur is in the power and energy recording device specifically for revenue purposes.

What are the other types of electric meters which uses multi-function? A multi-function meter is a combination device that performs the functions of instruments, transducers, and meters. It is flexible, allowing the user to monitor many quantities simultaneously. It contains a central processing unit (CPU) for the calculation and digital display of desired quantities. Most multifunction meters can be user configured to normally display a few quantities simultaneously while all quantities can be read using push buttons on the front of the device or via remote monitoring.

What are the different types of electric meters indicating and recording devices? Types of Meter Indicating and Recording Devices Each meter has a device that records the measured quantity. An electric meter usually has a register, which registers the integrating load. The demand meter has an indicating, graphic (recording), printing, or digital device. Digital device meters may also have communications circuitry to permit remote monitoring of the measured quantities.

What are the different types of electric meters used in power and energy reading? An electric meter is a device that measures and registers the integral of an electrical quantity with respect to time. The term “meter” is also used in a general sense to designate any type of measuring device including all types of electrical measuring instruments. Use of “meter” as a suffix to a compound word (e.g., voltmeter, ammeter, frequency meter) is universally accepted. However, in this chapter the narrow meaning of “electric meter” is used.

BULLETIN 1724D-112: APPLICATION OF CAPACITORS ON RURAL ELECTRIC SYSTEMS How power factor affect the systems loss in distribution system?                                   UNITED STATES DEPARTMENT OF AGRICULTURE                                                                  Rural Utilities Service                                                               BULLETIN 1724D-112 SUBJECT: The Application of Capacitors on Rural Electric Systems. TO: RUS Electric Borrowers and RUS Electric Staff EFFECTIVE DATE: Date of Approval OFFICE OF PRIMARY INTEREST: Distribution Branch, Electric Staff Division AVAILABILITY: This bulletin is available on the Rural Utilities Service website at http://www/ .usda. gov/rus/electric. INSTRUCTIONS: Replaces rescinded Bulletin 169- 1 PURPOSE: To provide Rural Utilities Service (RUS) borrowers and others guidance on the use, characteristics, and benefits of power factor correction capacitors on rural distribution systems. To view the

Which is better for voltage regulation, capacitor ot voltage regulator? One of the greatest advantages gained by the proper sizing and location of distribution capacitors is voltage improvement. By placing leading volt-amperes reactive (VAR) loads (capacitors) near lagging VAR load centers (motors for example), the lagging VARs on a system basis are cancelled with an associated increase in voltage.

What is the difference between substation capacitor and line capacitors? If capacitors are installed primarily to reduce or eliminate bulk power charges for kVAR or for other reasons associated with wholesale purchased power such as contractual requirements, they can be installed in substations to supplement distribution line installations. Installed equipment cost for substation capacitors may be less than that for the same amount of line kVAR because the substation units can package many kVAR in a single installation and can be switched with a single three-phase switching device and control unit. However, the distributor does not get the benefit of reduced distribution line losses by installing capacitors at substations, so such installations should be made only after the maximum practical amount of line capacitors has been installed.

CAPACITOR OPERATION AND MAINTENANCE Basic operation and maintenance of capacitor in distribution system Capacitors on distribution lines must be kept operational if their benefits are to be retained. Lightning surges or other disturbances occasionally cause capacitor fused cut-outs to open, and the distributor should promptly check and refuse such units to keep all capacitors operational. Care should always be taken in refusing capacitor units, since energizing units that have been damaged internally often results in capacitor case failure. Since no consumer complains when a capacitor cut-out opens, some distributors might delay returning the capacitor to service. However, such delays are costly to the distributor because of increased line losses and possible wholesale power factor surcharges. Switched capacitors need to be checked periodically to ensure proper operation of switches and controls. Operation counts should also be recorded. A large or small number of operations may i

CAPACITOR PLACEMENT AND CAPACITOR & VOLTAGE REGULATORS How does capacitor and regulators affect each other during operation? The installation of capacitors on a feeder can interfere with the proper operation of voltage regulators on that same feeder. This problem is relatively simple to overcome, but should not be ignored. Even fixed capacitors can cause some interference with regulators, but the interference is greater with switched capacitors. Capacitors, either fixed or switched, installed on the upstream side of the load center of a voltage regulator’s line drop compensator setting can thwart the compensator’s reactance setting. This problem is easily solved by setting the reactance compensation to zero and increasing the resistance compensation enough to achieve the same results previously obtained with both types of compensation. A voltage controlled switched capacitor on the load side of a voltage regulator can fail to switch properly because of action being taken by

TYPES OF SWITCHED CAPACITOR CONTROLS PART 2 What are the different types of switched capacitor control? In continuation of the types of switched capacitors control, we have include some intrinsic characteristics of the power system as the basis for capacitor switching which includes;  voltage, current, kvar, power factor, and combination of some of mentioned capacitor controls. Voltage Control A voltage control switches a capacitor on when line primary voltage is low, and switches the capacitor off when the voltage is high. The advantages of a voltage control include: (1) Primary line voltage is often closely related with line load and power factor, so the control responds to actual conditions; (2) Line voltage is an important index of the overall quality and efficiency of the feeder, so the control responds to a critical line condition; (3) It is simple to install, set, test and maintain; and (4) Although it requires a voltage signal, it does not require a line curre

TYPES OF SWITCHED CAPACITOR CONTROLS PART 1 What are the different types of switched capacitor control? There are many methods of automatic control of switched capacitors. The On and Off switching controls can be achieved by a time clock, an ambient temperature sensor, a line voltage-sensing device, a line current-sensing device, a power factor sensor, line kVAR flow sensing or other means such as a remote control. Different types of capacitor controls can be used for various installations on the same feeder, and combination control schemes can be used even on a single installation. The following is a summary of the advantages and disadvantages of various capacitor control methods. Time-Clock Control A time-clock control switches a capacitor on for those hours of the day when load is expected to be the highest, and switches the capacitor off for expected light-load hours. Controls are available that automatically change the on-off schedule during weekends or even seas

TYPES OF CAPACITOR INSTALLATIONS What are the types of Capacitor Installation known? Capacitors are relatively easy to install and are among the most trouble-free electrical devices. Line capacitor installations are protected with conventional cut-out fused switches, and capacitor failure is rare if the appropriate fuse element is used. (Fuse rating should be closely coordinated with capacitor size.) There are several types of capacitors (see figure below). Following Load Reactive Power The most difficult aspect of capacitor application is the maintenance of proper balance between total kVAR of capacitors connected at any particular time and load kVAR present at that time. Like load kW, load kVAR changes over time, so some provision must be made to vary the total connected capacitive kVAR to roughly follow the load kVAR. Installing capacitors based on the peak load kVAR and leaving all these capacitors connected at off-peak times is strictly inadvisable, since excessive capaciti

CAPACITORS FOR POWER DISTRIBUTIONS SYSTEM How does Capacitors installed in the power distribution system affect the operation? The basic definition of a capacitor would be that it is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator). Capacitors are used as parts of electrical systems, for example, consist of metal foils separated by a layer of insulating film. When there is a potential difference (voltage) across the conductors, a static electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field. An ideal capacitor is characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them. Th

RUS BULLETIN 1724E-300 SUBSTATION VOLTAGE REGULATORS Voltage Regulators for Distribution System General Both three-phase and single-phase voltage regulators are used in distribution substations to regulate the loadside voltage. Substation regulators are one of the primary means, along with load-tap-changing power transformers, shunt capacitors, and distribution line regulators, for maintaining a proper level of voltage at a customer’s service entrance. A very important function of substation voltage regulation is to correct for supply voltage variation. With the proper use of the control settings and line drop compensation, regulators can correct for load variations as well. A properly applied and controlled voltage regulator not only keeps the voltage at a customer’s service entrance within approved limits but also minimizes the range of voltage swing between light and heavy load periods. The substation regulators may be located on individual feeders or in the transformer secondary