ELECTRIC ENERGY MANAGEMENT
INTRODUCTION
Institutional, commercial, and industrial facilities are likely to have higher profits level and reduced operation costs if they implement strategies that can enable them to utilize electric energy efficiently. Systems and machines that run on electronic motor account for the highest amount of electrical power. The energy consumption is an indication that electrical energy is essential to various industries across the United States. Electric systems have different components that are responsible for mechanical transmission, power supply, and control of the motor. Routine inspection is an essential part of energy management as it enhances efficiency. The scanning of the components is necessary for the minimization of electrical losses. An expert responsible for the operation of the electrical system should ensure there is a proper distribution of power to reduce energy losses.
POWER SUPPLY
National Electrical Manufacturers Association (NEMA) is a body that gives guidelines to designers and manufacturers concerning specifications and motors. Several factors influence manipulation, choice, installation, and preservation of a machine or system that relies on mechanisms of an electrical motor. NEMA has stipulated the following service conditions for generators and motors:
- The design of motors is based on phases number, voltage, and frequency.
- The current supply must meet the requirements of the motor’s model.
- The motor must have an allowance of 10% of the specified voltage.
- The frequency of the motor must deviate within a 5% range.
CONSEQUENCES OF LACK OF VOLTAGE BALANCE ON INDUCTION MOTORS’ WORKING
Windings are likely to occur if voltages supply in an induction motor lack even distribution. The unequal distribution of energies is expected to lead to an unbalanced supply of currents. The conditions of voltage unbalance are likely to make the motor have increased temperature, thereby reducing its efficiency. Motors that operate with balanced voltages run smoothly and are useful in various circumstances. The number of voltages flowing through a machine should have even distribution to reduce the possibility of making the motor dysfunctional. The complex problem of unbalanced voltage is a result of a combination of both inappropriate variations in the current of the engine and a derating factor. Machine operators should make devices that are likely to experience current overload to be receptive to IMAXIMUM. The operators, furthermore, should make the machines responsive to IAVERAGE.
MOTOR
The concept of an electric motor was conceptualized in 1831 by Michael Faraday when he explained laws governing the operation of electromagnetism. The electric motor is used to produce mechanical energy by the conversion of electrical power. The measurement of the efficiency of an electric motor is direct. The idea, therefore, means that if the motor has an ability of 90%, it implies the motor converts only 90% of electrical energy. In this case, the input is electrical energy, while the output is mechanical energy. The amount of energy consumption of the motor is the result of the subtraction of the mechanical energy from the electrical energy. An estimate by one of the largest manufacturers suggests that the sale of electric motors in the United States exceeds two million. Around a sixth of the total sales regard motors that have high-efficiency.
GLOSSARY OF RECURRENT MOTOR TERMS
Full Load Amps: It is the quantity of current that the electric motor can drain, given the condition of full load.
Locked Rotor Amps: This is the quantity of current electric motor that has the capability of draining, given the condition of full voltage application.
Service Factor Amps: This is the current amount the motor can draw when it is under an overload of voltage. The overload, however, must have the same amount as the motor nameplate. If a motor can contain an overload of 15%, it has a service factor 1.15.
The Service Factor Amperage: It is the current amount the electric motor can extract under the condition of the service factor load.
Code Letter: This is the necessary amount of current flowing through the motor at the beginning of its operation. Code letters of motors assist in ratings of the motors when full voltage flow through them.
Efficiency: This is the fraction of the input electrical power that the motor converts to an output. The nameplates of electric motors manufactured for domestic purposes have efficiency indication.
Power Factor: Power factor is an indication of the requirements of a motor’s magnetizing amperage. Mathematically, it is represented as ACTIVE POWER (W) to APPARENT POWER (VA) ratio. In other words, the result of the division of Active power by Apparent power. The motors can avail of cost advantage when there is the constancy of power factor loads, and there is an absence of capabilities of system load. The continuous application of ASD has raised the sophistication of the system power factor.
POWER QUALITY REQUIREMENT
Operators of electronic circuits should be careful as they install the devices to mitigate any power-related challenge. Adjustable speed drive (ASDs) have electronic circuits that are likely to experience a fault related power supply. The power-related difficulties that can hinder the effective operation of the motors are a distortion of harmony, sags of voltage, and transient overvoltage. Customers are highly advised to correct faults related to power factor using capacitors. Unproportionate harmonics have the potential of causing capacitor failures, overheating of transformer, motor, and conductor. The error, additionally, can make controls and relays to operate ineffectively.
POWER METER:
The availability of load measurements can enable one to comprehend the usage of electrical power over a particular amount of time.
ELECTRIC MOTOR EFFICIENCY
A motor has the efficiency that is equal to the ratio of the output of the mechanical power to the input of electrical power; when energy losses are minimized, the motor gains more efficiency, thereby enabling it to accomplish a task with less energy amount.
MOTOR EFFICIENCY MANAGEMENT
Proper energy management is possible through the evaluation of every part of the motor’s system. The different parts of the motor work together to make the machine functional, and it, therefore, appropriate to ensure every part of the system works. Consumers prefer products with the most efficiency in the market, thereby making them less efficient commodities unmarketable. Efficiency management of a motor is more appropriate than the improvement of the parts of the motor.
Monitoring Energy Consumption
The first step to effective energy management is to have an exact measure of energy usage, and it entails reading of meters. Although an individual may have readings from their utility companies, readings from their meters are more reliable in this circumstance. Varied factors influence the frequency of getting meter readings. Subclause 3.5.1 of BS EN 16001:2009 ensures an obligation of measuring, monitoring, and recording of essential consumption of energy is upon the organization. The weekly control of energy consumption is more appropriate than the monthly style of supervision. An overload of data and interpretation challenges are some of the problems that the monthly approach of monitoring presents. Information on driving factor and energy consumption form part of the data that makes patterns of energy usage comprehensible.
Energy-metering Technologies
Some individuals are quite comfortable with reading a single meter that is responsible for indicating usage of energy in an entire building or facility. On the other hand, some people prefer having separate meters for both regular and significant electricity uses. Appropriate technology for energy measurement is key to the achievement of the utmost accuracy. The cost factor plays an integral role in the choosing of the proper technique. BS EN 16001:2009 cannot display standards of accuracy while subclause 3.5.1 is capable of laying down the accuracy standards. The latter technology, therefore, is more appropriate for energy reading usage.
Electricity Meters
Smart meters of electricity have variations that make them more functional. The new electricity meters can have a direct connection to supply cabling or at the points where current is more than 100 amperes, and it is channeled through transformers. A current transformer (CT) comprises of magnetic material with a ring shape, which provides passage for power cables. A secondary winding is created when the current of the load moves in the form of voltage. Convenient location and reading of meters are some of the advantages of indirect connection. On-board diagnostics increases the efficiency and reliability of meters with advanced structures. The function of an indication of power quality harmonics is carried out by onboard diagnostics.
Data Collection
There are two various forms of data collection: automatic and manual methods. An automated meter reading (AMR) is a system that makes it possible for remote readings. AMR, furthermore, gives data regarding consumption patterns of a particular consumer. The AMR system has many advantages, including instant and convenient reading of meters. The system enables utility providers to have power readings of areas with access restrictions. The system provides a convenient way of monitoring the power usage of tenants of a facility, thereby providing better service delivery.
Monitoring
It is prudent to undertake the monitoring of energy consumption after the strategy of energy management has been formed. The energy supervision process makes three functions possible: evaluation of the progress, to point out workable measures, and to indicate unworkable means. The steps in the monitoring process are varied, and the first one involves monitoring of the program to ascertain energy consumption measure. It is advisable that every type of energy used to be monitored with distinct graphs. The monitoring process of the energy types can be effectively carried out after establishing a base by graphing energy consumption for the last twelve months. The best way to undertake the monitoring process of energy consumption is to have distinct fuel accounting procedures and electric meter. For evaluation purposes, there should be a graph to display monthly energy usage. The evaluation process helps in ascertaining whether the plan of energy management is useful. If the evaluation reveals, there is no decrease in energy usage, the different parts of the equipment should be checked to ascertain their efficiency levels. Machine parts that have low efficiency consume energy, and this is a source of energy leak. The defective parts of the machine can then be improved to make energy management more effective.
RECENT DEVELOPMENTS
The availability of accessible sensors with low-cost and energy management systems that rely on computer operation are the developments that have caused a revolution in energy management.
Energy Maintenance Management Systems
A management system that many experts prefer has specific characteristics: the ability to record the data of the recent production and costs of energy. The prices of energy usage by each department in the facility should be available. The energy management systems should be able to promptly avail costs of projected energy against the actual amount of energy usage. A management file for the systems should have the following information:
- The equipment in maintenance should have an identification number.
- Theks,ecklists, and instructions of the maintenance process.
- Frequency of the tasks of maintenance.
- Essential skills.
- Equipment for fault and repair diagnosis.
- Justification and priority of the energy maintenance systems.
- Essential repair parts.
The management systems have the potential to improve energy usage of a facility if the parts of the machines undergo periodical and proper maintenance. The machines, furthermore, should be of latest technology to improve efficiency of the system.
New Sensors and Monitoring Equipment
- Data Loggers
The data loggers have within them computer microprocessors, sensor, and data storage unit. A software system is the basis of the operation of the data loggers and this characteristic has the potential of making them efficient and prompt in their operation. The loggers of data have the advantage of indicating the condition of the equipment for appropriate maintenance measures to be taken.
- Ultrasonic Detectors
The detectors are used to monitor steam traps operation. Ultrasonic detectors, furthermore, detect presence of steam leaks in a system. A technician can then make necessary repairs to improve the system’s operation.