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TECHNICAL LOSSES IN ELECTRIC UTILITY BUSINESS - WHAT IT IS AND WHY IT MATTERS TO ALL

The Technical Losses - Distribution Sector of Electric Energy - has always been a subject left in the shadows in the Electric Sector, probably because of the difficulties in quantifying them with precision.

The most significant Technical Losses in distribution system occur in the primary drivers in Distribution Transformers and secondary conductors, and are generally neglected the losses in the branches connecting the consumer. Today this division between Technical and Commercial Losses that the proportion of 58% for Technical Losses and 42% for Commercial Losses.

What has always been done is an approximate calculation and in many cases imprecise and rudimentary, without taking into account, the Characteristics and Load Profiles of Substations, Feeders and Distribution Transformers. As these Technical Losses have always been added to the price paid by the consumer - KWh - in their monthly bills, precisely because of this, Utilities have left this subject in standby mode.

But today this is an area where big steps forward are already being taken. Due to its size and scale, little has been done in the past to understand to a great extent what happens within these networks. However, with a number of technological developments in Smart Grid devices, Utilities can gather new levels of data.

In fact, the level of Technical Losses is a mirror that reflects the health, age and conservation of all the assets of an electric energy distribution network. The assessment of quality and reliability of supply of electricity is a concern common to Utilities, and is directly related to the Technical Losses which require simple and reliable indicators that measure the quality of electricity supply to the target well investments and resolve issues.

A new approach is to use data from Smart Meters to transform how the Technical Losses can be understood, identified and addressed. This issue can no longer be seen as an unavoidable reality. The availability of data will enable the Technical Losses to be more readily evaluated. Evaluating these data can help move innovative ideas and the continuous improvement of the entire network, and identify areas of high loss that will benefit from this targeted reinforcement.

The cost of Technical Losses should take into account the variable price of electricity during the day, rather than an average price. Technical Losses in distribution systems are directly related to consumers' load curves, which vary due to seasonality and or rapid changes in load over the year, resulting in uncertainty in determining the amount of losses. These uncertainties can be determined from the elaboration of a decision support system that considers the random nature of Load Curves through a set of measurements along the Feeders.

In addition, by using the data to optimize Voltage Levels to suit the customer's appliances, it expects to reduce Energy Demand and Technical Losses. From changing voltage levels to meeting real demand, scheduling maintenance operations based on the current state of the assets rather than their expected state, networks can take up the challenge of getting more of the aging resources rather than replacing them.

Below is an example of a basic architecture for a SCADA monitoring and supervisory system for a Technical Losses Feeder, and by analogy of an entire Substation.

1-Put at output of the Feeder of a Substation, a Smart Meter + Power Transformer + Current Transformer + Calibration Key

2-On each Distribution Transformer, put a Smart Meter + Current Transformer.

3-Put a Smart Meter on each consumer unit

4-The consumption of all Smart Meters installed in the Distribution Transformers must be summed up and compared with the Smart Meter installed in the Feeder. With this, we can see the difference between what the Feeder provided for the Media Voltage Grid, and which each Distribution Transformers provided to the consumer units. The difference between what the Smart Meter in the Feeder has measured and the sum of the metering of all Smart Meters in the Distribution Transformers can’t exceed 5%. Of course, this value depends greatly on the length of the Feeder.

5-The power consumption of the Smart Meters of the consumer units will be summed up and compared to the Smart Meter of the Distribution Transformer, and this difference can’t be greater than 4%.

For Technical Losses, the optimal level is a function of topology and net length, materials and equipment used, the behavior of the Load (balance, load factor, demand maximum permissible loading level, etc.). The assessment of quality and reliability of supply of electricity is a concern common to Utilities, and is directly related to the Technical Losses which require simple and reliable indicators that measure the quality of electricity supply to the target well investments and resolve issues.

Today with Distributed Generation, competition is everywhere and is diversified, so the price of tariffs has a huge impact. Adding to the price of KWh the cost of Technical Losses, may not be an easy exit, is that the supply of energy is becoming more plural.

Content Discussion

Dave Bryant's picture
Dave Bryant on March 6, 2018

Great article, Joao. Its noteworthy that reducing system losses / line losses can also serve to reduce fuel consumption and associated emissions, while freeing up generation capacity that is otherwise wasted. The use of modern conductors such as ACCC can also help meet these important objectives.

Joao Batista Gomes's picture
Joao Batista Gomes on March 6, 2018

Thanks Dave!

Joao Batista Gomes's picture
Joao Batista Gomes on April 10, 2018

The Reactive Power produces an increase in losses in the power grid and reduces the voltage level on consumers. It can be assumed that the transmission lines and power distribution are sources of reactive power due to its reactance.

Active Energy is one that effectively produces work, examples: the lighting of a lamp, the motor turning. The more Reactive Energy in Grid becomes less efficient Energy Distribution, control of this type of energy is essential for Utilities. Reactive Energy does not produce Work, but it is important to create the Magnetic Flux in the coils of motors, transformers, generators and other equipment. The use of Reactive Energy should be as small as possible. Excess Reactive Energy demands, for example: driver section and larger Transformer of higher capacity, and cause Losses for heating and voltage drop.