Electric Energy Measurement - Fair Billing and Correct Calculation Power System Technology

Electric energy measurement standard refers to fair billing and correct calculation of economic and technical indicators of power system. Strengthen the management of electric energy measurement devices (including active and reactive electric energy meters, multi-rate electric energy meters, maximum demand meters, pulse electric energy meters and multifunctional electric energy meters, voltage and current transformers for metering, and secondary circuits, etc.) to ensure The accuracy and uniformity of the electric energy value and the safety and reliability of the metering device are effective ways to improve the metering standard of electric energy.

1. Background of electric energy measurement

Electric energy is an indispensable energy for social development and people's daily life. With the continuous improvement of the market economy, the commercialization of electric energy has become an inevitable way. The most intuitive way to measure the user's electricity consumption is electric energy measurement, which can also be reflected in the degree of standardization of electric energy measurement. The management level of power supply enterprises.

Electric energy measurement is the most direct window for users and the most intuitive yardstick to reflect the management level, qualification and reputation of electric power enterprises. Standardized measurement is the basis of power supply enterprise management and a very important part of enterprise operation and management. The degree of standardization of measurement is directly reflected in the economic benefits of enterprises.

2. The effect of electric energy measurement standards on energy saving and consumption reduction

Electric energy measurement is not only the basic technical support and basic data source for electricity market transactions and marketing, but also the basic data source for production technology units to judge whether the equipment is running economically. Through accurate measurement and accounting, it is possible to analyze power transformers in operation, etc. Whether the loss of power grid equipment exceeds the allowable value, deal with or replace high-loss power grid equipment, and reduce the unit energy consumption of the enterprise.

2.1 Scientific and advanced electric energy measurement tools provide accurate data for energy-saving renovation

The direct source of main data such as voltage, frequency, active power, and reactive power is the electric energy measuring instrument. The accuracy and technological advancement of measuring instruments will directly affect the generation and analysis of data. Power supply enterprises should increase investment, update energy measuring instruments and carry out technological innovation, so as to obtain accurate and systematic measurement data in a timely manner.

2.2 Analysis of electric energy measurement data provides a scientific basis for energy-saving renovation

It is necessary to continuously strengthen data analysis and seek benefits from measurement management. Through the implementation of energy-saving monitoring of power grid equipment in operation, research, analysis and evaluation based on accurate measurement data, existing problems can be found, and energy-saving technological transformation and operation mode adjustment of power grid equipment can be carried out in a targeted manner, effectively improving the utilization rate of electric energy and reducing energy consumption. Reduce power loss and improve the economical operation level of the power grid.

3. Electric energy measurement standard

The configuration of the measuring standard shall comply with the following principles:

3.1 The highest measurement standard device should be determined according to the highest accuracy level, measurement range and value transmission task stipulated by the superior competent department of the tested electric energy meter and transformer in the power supply area under its jurisdiction, but its accuracy level configuration must be appropriate.

3.2 The configuration of the working measurement standard device should be determined according to the accuracy level of the electric energy meter and transformer to be tested, the annual verification workload and the work quota of the unit.

3.3 Measurement standards must be complete.

3.4 Use a measurement standard with a simple measurement verification method.

3.5 The electric energy measurement institute (room) should establish and configure corresponding electric energy measurement standards and test equipment according to the classification of electric energy value transmission in the power system and the regulations of the superior competent department.

4. Management of electric energy measurement standards

4.1 All measuring standard instruments and verification devices in use should go through the measurement standard assessment procedures and strengthen management in accordance with the provisions of the "Measurement Standard Assessment Measures". Newly built and in-use measurement standards should have a measurement standard assessment certificate issued by the superior competent department before they can be used; for the highest electric energy measurement standard, a measurement standard technical report, stability assessment records over the years and other measurement standard assessment files should be established ; For the certificate of passing the examination of the measurement standard, the application for re-examination shall be carried out according to the prescribed validity period, and the validity period shall be extended.

4.2 Among the verified measurement standards and verification devices, if the basic error is unqualified, it should be stopped and sent to the relevant department for repair and adjustment to restore its measurement performance; if the verification items are incomplete, it can be used within limited conditions.

4.3 In order to grasp the error changes of standard electric energy meters, electric energy meters and transformer verification devices in a timely manner, the electric energy measurement institute (room) should conduct error comparisons at least once every 6 months, and deal with problems in a timely manner.

4.4 The periodic verification of electric energy meters and transformers should strictly implement the national and ministerial metrological verification regulations, including verification items, verification conditions, error measurement points, verification methods, error rounding and verification results. For the verification of a large number of electric energy meters of the same type, after strictly adjusting the error and controlling the error sign, and confirming that the measurement verification regulations are met within the entire effective load range, the error measurement points can be appropriately reduced.

4.5 When the actual error of the verified electric energy meter is greater than 70% of the basic error limit, the error adjustment should be carried out again. When the actual error of the verified transformer is close to the basic error limit, technical improvement measures should be taken to reduce the measurement error.

4.6 The verified electric energy meters and transformers, the seals, verification marks or verification certificates, the verification certificates or verification result notifications issued, and the original verification records shall be issued by the Provincial Electric Power Bureau according to the State Council and local metrology administrative departments. , Metrological verification procedures, and combined with actual use requirements for unified regulations.

5. Improve the standardization method of electric energy measurement

5.1 Technical Standardization

To achieve the standardization of measurement, we must first provide technical support, and form a system, method and system in technical management to meet the requirements of relevant standards, which are mainly reflected in the following aspects.

5.1.1 Improve measurement accuracy and promote the standardization and normalization of measurement instruments

5.1.1.1 Technical transformation to eliminate outdated products

Replace the electric energy meters that are banned or eliminated by the state, gradually realize remote meter reading and metering digitization, and improve the level of metering automation management. The electric energy measurement device must meet the requirements of the metering regulations, choose a multi-functional electric energy meter with high precision and good stability, and use a special secondary circuit for current and voltage transformers, which is not shared with the protection and measurement circuits. According to the requirements of the measurement regulations, carry out the transformation of the measurement points and improve the electric energy measurement devices.

5.1.1.2 Metrology supervision strengthens inspection

Strictly implement measurement supervision, intensify the inspection of electric energy meters, secondary voltage drop and comprehensive error testing, and transformer ratio adjustment assessment, give full play to technical advantages, and improve measurement accuracy. Select the required accuracy level according to the type of load, and do a test adjustment before putting into production, so that the error of the metering device meets the standard requirements.

5.1.1.3 Operation management weekly inspection and rotation

Strengthen the electric energy measurement operation management, and carry out periodic verification and rotation according to the regulations. The combined errors of voltage and current transformers can be controlled with accuracy levels within the required secondary load range. The error caused by the voltage drop of the secondary conductor of the voltage transformer cannot be directly measured by accuracy, and it occupies a considerable proportion in the comprehensive measurement error. It can be compensated by adjusting the error complementation of the transformer reasonably or using the voltage error compensation of the secondary conductor The device is compensated to reduce the comprehensive error of measurement.

5.1.2 Strengthen the comprehensive analysis of meter selection and metering to improve the accuracy of metering

5.1.2.1 Correct Wiring

According to the different situations of the power system, correct electric energy measurement and wiring methods are adopted to reduce measurement errors.

5.1.2.2 Reasonable positioning

Reasonably select the location of the metering point, as close to the site as possible, reduce the secondary load of the transformer and the loss of the secondary circuit, and improve the metering accuracy.

5.1.2.3 Reasonable selection

Reasonably select the transformation ratio of the current transformer. The normal load current is more than two-thirds of the rated current of the current transformer. For strong seasonal loads, a multi-tap current transformer is used to ensure that the transformer operates within a high-precision range.

5.1.2.4 Comprehensive analysis

Carry out comprehensive analysis of metering points, advocate the overall calibration of metering devices, and carry out comprehensive error analysis to do a good job in the periodic calibration and periodic rotation system of electric energy meters and transformers, and the periodic inspection of the secondary voltage drop of voltage transformers.

5.1.3 Ensure that the testing equipment and conditions meet the standards

Strictly organize measurement supervision and regular calibration, and implement according to relevant standards. The standard electric energy meter and electric energy meter on-site calibrator shall be submitted for inspection once a year. All verified measuring standard instruments and standard devices should be stopped from use if they fail to pass the test, and should be repaired and adjusted, and can only be used after passing the test. On-site inspection conditions should meet the requirements specified in the regulations.

5.1.4 Continue to promote the use of advanced technologies

Constantly aim at the advanced technology and management experience of contemporary measurement, increase the modern scientific and technological content of measurement inspection and electric energy measurement management, and improve the measurement inspection system in combination with the actual situation of power supply enterprises.

5.1.5 Strengthen contact with professional departments and get technical support from superior departments

Actively strive for technical guidance and support from higher-level professional authorities, continue to learn, promote and apply new technologies and products, and create a good external environment for the in-depth development of power metering standardization.

5.2 Management standardization

5.2.1 Legal basis

Strengthen publicity, earnestly implement laws and regulations such as the "Measurement Law" and "Electricity Law", and regard them as the code of conduct for enterprise measurement activities, and manage electricity according to law.

5.2.2 Leadership attention

In terms of organizational management, it is necessary to establish an organizational form that is directly managed by the top executives, and put the electric energy measurement management work in a prominent position.

5.2.3 Establish rules and regulations

Establish and improve various systems including "Measurement Management Technical Specifications", "Measurement Standard Periodic Inspection System", "Measurement Standard Technical File Management System", "Measurement Standard Use and Maintenance System", "Periodic Verification (Rotation) System", "On-site Inspection Management System", etc. The system of standardized management in all aspects of electric energy measurement management ensures the accuracy and reliability of standard measurement instruments and measuring instruments in use.

5.2.4 Cooperation between departments

Pay attention to the cooperation, control and connection of the work of various departments and positions, and adopt closed-loop dynamic management for all aspects of measuring instruments from type selection, purchase, equipment, filing, testing, maintenance, inspection, scrapping, etc., with responsibilities assigned to people and measures in place. Strict reward and punishment system.

5.2.5 Mandatory inspection

Strengthen the mandatory verification of electric energy meters, use the on-site calibrator to calibrate the meters according to the verification regulations for newly purchased and in-use meters, and send the unqualified meters to the designated metering station for full index inspection and experiment , if it is unqualified, the user is required to replace the meter, so as to control the use of unqualified meters, and at the same time establish an original file for each meter for filing management. It also reduces the loss caused by inaccurate measurement for users, and establishes a good image of the enterprise.

5.2.6 File Management

Perfect measurement files, so that dedicated personnel are responsible for improving the level of electric energy measurement management. Establish accounts for various records, drawing materials, verification certificates, instruction manuals, etc. in the measurement management, and carry out dynamic file management, supplement and update data at any time, ensure the accuracy of the data, and facilitate comprehensive analysis. Guarantee the accuracy and reliability of the data of metering instruments, and provide an effective legal basis for normal metering and charging.

5.3 Standardization of personnel and services

5.3.1 Team building

Strengthen the construction of measurement teams, improve the quality of measurement personnel, and develop intellectual and human resources for the sustainable development of electric energy measurement work.

5.3.2 Technical Exchange

Strengthen technical exchanges and technical training, and improve the technical quality of measurement personnel. Improving the technical quality and professional ability of measurement personnel has a positive effect on promoting the standardization and standardization of electric energy measurement management. It is necessary to regularly organize measurement management personnel to carry out political and business studies, and constantly study and discuss new situations and new problems in measurement management. Combining the characteristics of measurement management in different enterprises, organize training courses in a targeted manner, listen to the lectures of measurement experts, learn theories about measurement technology, and understand the performance and development direction of electric energy measurement products. Make the measurement personnel systematically study the theory of electric energy measurement technology and improve the technical quality of the measurement personnel.

5.3.3 Consulting Services

Carry out power metering consulting services for users, widely publicize the relevant knowledge of metering use, make users understand the work procedures and necessity of metering testing, actively cooperate with metering management, and make metering standardization work go on smoothly. At the same time, it is necessary to improve the service quality of social metrology and testing work, and to build an effective communication bridge between the supply and demand sides based on the principles of openness, justice and fairness, and promote the standardization of metrology in an all-round way.

5.3.4 Service Standards

Strengthen the implementation of service standards and vigorously promote service standardization. Establish and improve service standards and reward and punishment standards for business office services, service systems and business processes, charging standards, maintenance and assembly and disassembly services, emergency repair and emergency services, and service supervision. The service standard is further refined to every move of personnel, every minute and every second of time, and every minute and every cent of cost. Standardize all operation approval procedures, strengthen the supervision and inspection mechanism, increase rewards and punishments, so that the service level has been greatly improved. The in-depth implementation of electric energy measurement standardization work is an important means for power companies to adapt to market competition and an important basis for demand-side management advocated by the state. It is closely related to enterprises saving power supply costs, reducing power loss, improving power supply quality and reliability, and grasping economic indicators in real time. Therefore, enterprise managers should fully understand the significance of metering standardization management, and actively promote standardized management innovation while continuously improving power metering standardization management, so as to improve the production efficiency and economic benefits of power supply enterprises.