12-08-2013, 03:27 PM
A METHODOLOGY FOR THE DESIGN OF AN ELECTRICITY THEFT MONITORING SYSTEM
DESIGN OF AN ELECTRICITY .docx (Size: 70.57 KB / Downloads: 22)
ABSTRACT
The purpose of this work is to provide an algorithm for the design of electricity theft monitoring system which allows violators to be detected at a remote location. It begins with the analysis of losses in electrical power systems. The bulk of these losses are caused by electri city theft, rather than other possibilities such as poor maintenance and calculation and accounting mistakes, though some power systems may suffer from both. Other aspects discussed include the various forms of theft practices, methodology for detection of theft, generating the theft case algorithm using the backtracking algorithm method and communicating these data from the consumer premises to the substation using the existing power lines. Appropriate conclusions and recommendations were given from the information gathered.
INTRODUCTION
According to Smith [1], electricity theft can be in the form of fraud (meter tampering), stealing (illegal connections), billing irregularities, and unpaid bills. The evidence of the extent of electricity theft in a sample of 102 countries between 1980 and 2000 shows that theft is increasing in most regions of the world. The financial impacts of theft are reduced income from the sale of electricity and the necessity to charge more to consumers. Electricity theft is closely related to governance indicators where higher levels are recorded in countries without effective accountability, political instability, low government effectiveness and highlevels of corruption.Merely generating more power is not enough to meet present day requirements. Power consumption and losses have to be closely monitored so that the generated power is utilised in an efficient manner. This illegal electricity usage may indirectly affect the economic status of a country. Also the planning of national energy may be difficult in case of unrecorded energy usage.This paper discusses the design of an algorithm to monitor distribution systems for theft.
ANALYSIS OF LOSSES IN POWER SYSTEMS
Losses occur at all levels, from generation, through transmission and distribution, to the consumer and the meter. It is normally at the distribution level where the majority of avoidable losses occur. All electrical power distribution companies operate with some accepted degree of losses. This is no different from the scenario in Ghana. Losses incurred in electrical power systems have two components:
• Technical losses and
• Non-technical losses (Commercial losses)
Technical Losses
Technical losses will always arise as the physics of electricity transport m eans that, no power system can be perfect in its delivery of energy to the end customer. Technical losses are naturally occurring losses (caused by actions internal to the power system) and consist mainly of power dissipation in electrical system components such as transmission lines, power transformers, measurement systems, etc. Technical losses are possible to compute and control, provided the power system in question consists of known quantities, viz., resistance, reactance, capacitance, voltage, current and power. These are routinely calculated by utility companies as a way to specify what components will be added to the systems. Loads are not included in the losses because they are actually intended to receive as much energy as possible. Technical losses in power systems are caused by the physical properties of the components of power systems. Example, I2R loss or copper loss – in the conductor cables, transformers, switches and generators. The most obvious example is the power dissipated in transmission lines and transformers due to their internal impedance. Technical losses are easy to simulate and calculate; computation tools for calculating power flow, losses, and equipment status in power systems have been developed for some time.
Non-Technical Losses (Commercial Losses)
These refer to losses that are independent of technical losses in the power system. Two common examples of sources of such losses are component breakdowns that drastically increase losses before they are replaced and electricity theft. Losses incurred by equipment breakdown are quite rare. These include losses from equipment struck by lightning, equipment damaged by time and neglect. Most power companies do not allow equipment to breakdown in such a way and virtually all companies maintain some form of maintenance policies.
METHODOLOGY FOR DETECTION
The method includes receiving meter data of the measured power consumed by a customer, receiving delivered power da ta that includes data of the power delivered to the customer, determining a difference between the meter data and the delivered power data, determining that the difference between the meter data and the delivered power data is greater than a predetermined amount, and indicating a discrepancy if the difference between the meter data and the delivered power data is greater than a predetermined amount. In addition, the method may include determining that a discrepancy varies over time by a predetermined amount and providing a discrepancy notification through power lines. The block diagram in Figure 3 shows the basic components of the system mentioned.
CONCLUSIONS
Electricity theft, a common form of commercial losses, involves tampering with meters to distort the billing information or direct connections to the power system. Commercial losses are nearly impossible to measure using traditional power system analysis tools. This is due to the lack of information on both commercial and the legitimate loads in the system, which translates to insufficient inputs for any meaningful loss calculations. Despite the best efforts by utilities, the current results of commercial losses meas urements are often inaccurate at best, because the figures rely heavily on the records of detected cases, rather than by actual measurement of the electrical power system. Certainly utilities have some control over the magnitude of commercial losses; but even with their best efforts, some commercial losses will still continue. An algorithm for the design of electricity theft monitoring system has been generated using the backtracking algorithm type.