Skip to main content

ELECTRICAL ENERGY CONSUMPTION

Electrical energy consumption is the electrical energy use by all the various loads on the power system. Consumption also includes the energy used to transport and deliver the energy. For example, the losses due to heating conductors in power lines, transformers, and so on is considered consumption.

Electricity is consumed and measured in several different ways depending on whether the load is residential, commercial, or industrial, and whether the load is resistive, inductive, or capacitive. Electric utilities consume electricity just to produce and transport it to consumers. In all cases, electrical energy production and consumption is measured and accounted for. The electrical energy produced must equal the electrical energy consumed.

IN RESIDENTIAL ELECTRIC CONSUMPTION: the larger users of electrical energy are items such as air conditioning units, refrigerators, stoves, space heating, electric water heaters, clothes dryers, and, to a lesser degree, lighting, radios, and TVs. Typically, all other home appliances and home office equipment use less energy and, therefore, account for a small percentage of total residential consumption. Residential consumption has steadily grown over the years and it appears that this trend is continuing. Residential energy consumption is measured in kilowatt-hours (kWh).

COMMERCIAL ELECTRIC CONSUMPTION: is also steadily growing. Commercial loads include mercantile and service, office operations, warehousing and storage, education, public assembly, lodging, health care, and food sales and services. Commercial consumption includes larger-scale lighting, heating, air conditioning, kitchen apparatus, and motor loads such as elevators and large clothes handling equipment. Typically, special metering is used to record peak demand (in kilowatts) along with energy consumption in kWh.

INDUSTRIAL ELECTRIC CONSUMPTION: appears to be steady. Industrial loads usually involve large motors, heavy duty machinery, high-volume air conditioning systems, and so on, for which special metering equipment is used such as power factor, demand, and energy. Normally the consumption is great enough to use CTs (current transformers) and PTs (potential transformers) to scale down the electrical quantities for standard metering equipment.

VERY LARGE ELECTRICAL ENERGY CONSUMERS: (i.e., military bases, oil refineries, mining industry, etc.) often use primary metering facilities to measure their consumption. These large consumers normally have their own sub-transmission and or primary distribution facilities including substations, lines, and electrical protection equipment.

Comments

Popular posts from this blog

ADVANTAGES AND DISADVANTAGES OF CORONA

Corona has many advantages and disadvantages. In the correct design of a high voltage overhead line, a balance should be struck between the advantages and disadvantages. ADVANTAGES (i) Due to corona formation, the air surrounding the conductor becomes conducting and hence virtual diameter of the conductor is increased. The increased diameter reduces the electrostatic stresses between the conductors. (ii) Corona reduces the effects of transients produced by surges. DIS-ADVANTAGES (i) Corona is accompanied by a loss of energy. This affects the transmission efficiency of the line. (ii) Ozone is produced by corona and may cause corrosion of the conductor due to chemical action. (iii) The current drawn by the line due to corona is non-sinusoidal and hence non-sinusoidal voltage drop occurs in the line. This may cause inductive interference with neighboring communication lines.

ADVANTAGES OF PER UNIT SYSTEM

PER UNIT SYSTEM The per-unit system expressed the voltages, currents, powers, impedances, and other electrical quantities basis by the equation: Quantity per unit (pu) = Actual value/ Base value of quantity ADVANTAGES OF PER UNIT SYSTEM While performing calculations, referring quantities from one side of the transformer to the other side serious errors may be committed. This can be avoided by using per unit system. Voltages, currents and impedances expressed in per unit do not change when they are referred from one side of transformer to the other side. This is a great advantage. Per unit impedances of electrical equipment of similar type usually lie within a narrow range, when the equipment ratings are used as base values. Transformer connections do not affect the per unit values. Manufacturers usually specify the impedances of machines and transformers in per unit or percent of name plate ratings. Transformers can be replaced by their equivalent series impedances. ...

ABSOLUTE AND SECONDARY INSTRUMENTS

The various electrical instruments may, in a very broad sense, be divided into (i) Absolute Instruments (ii) Secondary Instruments. Absolute Instruments are those which give the value of the quantity to be measured, in terms of the constants of the instrument and their deflection only. No previous calibration or comparison is necessary in their case. The example of such an instrument is tangent galvanometer, which gives the value of current, in terms of the tangent of deflection produced by the current, the radius and number of turns of wire used and the horizontal component of earth’s field.  Secondary Instruments  are those, in which the value of electrical quantity to be measured can be determined from the deflection of the instruments, only when they have been pre-calibrated by comparison with an absolute instrument. Without calibration, the deflection of such instruments is meaningless. It is the secondary instruments, which are most generally used in ev...