Dr. Nagesh Rajopadhyay, Manish Arora and P. Madhusudhan
Info Tech Enterprise Limited, Hyderabad
“The total power generation in the country was around one lakh MW of which billing was done only for 55,000 MW and the rest 45,000 MW was going as pilferage and power theft. Out of 45,000 MW, the annual power theft was around 30,000 MW causing a financial loss of Rs 20,000 crore to the nation’s exchequer every year – A report”
The Power sector plays a very important and vital role in the economic development of a country. The growth of development of Industries, Agriculture, Infrastructure, is dependent on the state of power sector. In India approx. 35-40% of the losses are contributed by Transmission and Distribution losses. These losses are much higher if we compare any other developed country.
Several State Electricity Boards (SEB), to identify the areas incurring high losses, have performed detailed Energy Audit. As the nature of the loss is both technical and commercial, it becomes more difficult to differentiate the loss in between these two factors. This can only be possible by making a detailed study of the system. As pilferage takes place mostly at the LT level hence it becomes crucial to carry out the study upto consumer level. The losses in the physical system like line losses, transformation losses forms the technical losses and removing the technical losses from total losses will give us the commercial losses in the system. Commercial losses come from a variety of sources, all of which have in common that energy was delivered but not paid for. The potential sources of commercial loss or the theft of utility service could be a direct connection from a feeder or wire bypassing the meter, tampering with meters or meter reader fraud. The SmallWorld Software from GE provides such facilities.
This paper emphasizes the role of GIS for identifying the network areas, which could be facing the problem of power pilferage.
GE-Smallworld software (version 3.1) was used at InfoTech to work out a prototype solution for the power pilferage over GIS. PTI engines were interfaced with this GIS for Network analysis and optimization. Data model was created in Smallworld for the land base as well as for the network. The steps involved in estimating power pilferage for a given substation is as follows;
- Interface billing system to GE-Smallworld by making Smallworld application software to read external RDBMS of Billing system.(See Figure -1)
- Get the billing related information filled into customer data
- Identify the total power given out (P-Total) by the substation and the total power billed to the customer (P-billed).
- Estimate the losses in the network (P-lost) using GIS and Network analysis package over the identified land base and the network data.
- Work out Power Pilferage (P-Pilferage) or commercial loss for the given substation as (P-Total)-(P-billed)-(P-lost). Plot the results on GIS.
- Work out the similar pilferage analysis transformer wise provided a meter is installed at transformer and the reading is available for the analysis. Plot the results on GIS.
In order to carry out the analysis for the pilferage it becomes very important to accommodate network related data fields in the customer table itself which can have the additional fields like: -Substation id, Subscriber no., Last bill date, Start date for present bill, End date for present bill, Circle code, Bill no., No. of units consumed and the Amount billed.
Out of these fields, except substation id, remaining fields are assumed to be available in the customer-billing database. A link has to be maintained between the external billing database and Smallworld database. Only the most recent billing data can be maintained in the Smallworld GIS customer table, so that the duplication of more data can be avoided. Following figure illustrates the interface
User has been provided with a provision to enter the units, metered during the billing period, at the time of loss evaluation. The billing data is populated simultaneously in external database and Smallworld database. After the entry of meter data at a substation level, system is asked to evaluate the total commercial loss. The methodology that can be adopted is outlined below in Figure -2
Fig. 2: Flowchart of Methodology
The procedure can be applied to all the feeders for the feeder wise commercial loss evaluation and for LT network also, provided the distribution transformer output is metered.
The losses obtained will be an approximate figure because of the factors
- There will be defective meters in the system and the units billed in those cases may not be correct.
- The assessments made regarding the loads while evaluating the technical losses
With this proposed system it is possible to access exactly the geographical areas in which the pilferages are maximum, which can be further avoided by enhanced level of vigilance and by making respective officers responsible for the related areas. Typically the area served by a substation is few sq km and hence the implementation of measures can be made more effective once the area is identified. Figure 3 shows the methodology in brief.
Fig. 3: Analyzing Pilferage at Substation Level
Identifying the individual subscribers and locations where thefts take place
It is also possible to detect theft of energy by an individual consumer, from his bills. Whenever there is a drastic reduction in the number of units he/she consumed, from the previous bill to present bill, he/she can be tagged in the network as suspected. The tag can be removed or retained after a physical check at the consumer premises.
Role of SCADA interfaced GIS system in identifying potential thefts in H.T. distributions
The proposed solution is interface of SCADA with GIS system. The SCADA system will continuously get the real time readings of all electrical parameters at monitored points on feeders. These parameters include, Voltage, Angle, Power Factor, Active Power, Reactive Power and Energy. The system shall also get the status of various switching devices like circuit breakers, switches and isolators. It will also get the transformer parameters like tap position, etc.
Electronic meters will be installed at HT consumers. These meters will be equipped with the interface for communications with the SCADA system. SCADA system will be communicating with the meters using an industry standard protocol. Meter readings shall be used to monitor the load and for detection of attempts to tamper with the meter. As soon as a tamper is detected the meter/consumer shall be tagged on the GIS system. The information shall be passed on to the vigilance groups for physical check, to take further action. The system can be graphically illustrated in Figure 4.
In this paper a GIS solution for preventing the power pilferages has been presented. The proposed methodology is tested on SmallWorld GIS software. It can be concluded from the above discussion:
- A GIS system integrated with consumer billing system can be very effectively used in detecting the power pilferage.
- Pilferage detection can be done at consumer, distribution transformer, and feeder or substation levels.
- The accuracy of the result depends on the accuracy of the loading pattern considered during the evaluation of technical losses and the accuracy of the meter readings.
- Analysis of patterns of individual consumption over GIS can help in identifying the sources of pilferage at subscriber level.
- GIS system integrated with SCADA can be used in detecting power thefts by HT consumers.