DL/T 448-2016: Electrical Energy Metering

• DL/T 448-2016 applies to technical management of all electrical energy metering devices in electric power systems for trade settlement and economic technical indicators, but not all energy metering devices.
• The technical management of energy information collection terminals can refer to DL/T 448-2016 for execution.
• For normative reference documents with a date, only the version of the cited document with the date applies. For those without a date, the latest version applies.
• An electrical energy metering device includes various types of energy meters, voltage and current transformers, and their secondary circuits but also includes electrical energy metering cabinets, boxes, and screens.
• The point of electrical energy metering is for electric grid companies to settle and assess energy or between electric grid firms and power generation or supply enterprises.
• Operational quality inspection involves testing samples of on-site electrical energy metering instruments and those that have been replaced or removed for verification or calibration.
• Temporary verification includes the accuracy verification of electrical energy metering instruments in operation or those replaced or removed when questions arise, and isn’t performed periodically.
• Electrical energy metering device technology management must comply with both the "Measurement Law of the People's Republic of China" and the "Electric Power Law of the People's Republic of China", as well as relevant laws and regulations.
• One of the objectives of electrical energy metering device technology management is to ensure the accuracy and traceability of electrical energy values.
• Management of electrical energy metering devices involves various aspects, including metering points, methods, schemes, design review, installation acceptance, operation, maintenance, troubleshooting, full lifecycle management, and related facilities.
• Electrical energy metering technology management adheres to the principles of division by supply business area, and is based on grid, power generation, and supply enterprise management, with classification, division of labor, supervision, coordination, and unified management.
• Grid companies are responsible for the technical management of electrical energy metering devices for trade settlement within their supply business area, including internal assessment of power used by power generation enterprises connected to the grid.
• Power generation enterprises are responsible for the technical management of electrical energy metering devices used for internal assessment, and cooperate with grid and power supply enterprises for trade settlement involving the enterprise.
• Power supply enterprises are responsible for the technical management of electrical energy metering devices for trade settlement and internal assessment within their supply business area.
• Substation operation departments and power users are responsible for the daily supervision of electrical energy metering devices.
• Grid companies' electrical energy metering technical organizations function as both technical service and supervision bodies within the grid.
• Grid companies establish electrical energy metering technology management systems that define the responsibilities of affiliated units and their technical organizations.
• Grid companies' electrical energy metering technical organizations should have the necessary electrical energy metering professionals, facilities, and equipment to meet work needs.
• Full-time engineers at grid companies' electrical energy metering technical organizations address difficult metering issues and manage metering standards.
• Grid enterprises develop planning for the construction of electrical energy measurement standard systems, and building and maintaining the highest measurement standards
• Power generation enterprises should have an electrical energy metering technical management organization and allocate full-time or part-time personnel for daily electrical energy metering technical management.
• Power generation enterprises should have an electrical energy metering technical organization and allocate full-time or part-time personnel to handle daily electrical energy metering technology management.
• Power generation enterprises should establish an electrical energy metering technical organization with necessary facilities, equipment, and technical personnel.
• Power generation enterprises should assist grid companies in the final inspection of energy metering devices used for trade settlements. They should also inspect, verify, replace, and handle failures of energy measurement equipment, and oversee and protect these devices.
• Full-time personnel in power supply enterprise electrical energy metering technical management organizations are responsible for technical research and development and routine management.
• Power supply enterprise electrical energy metering technical organizations should have specialized engineers to handle difficult metering technical issues.
• Operating energy metering devices are classified into five categories based on the importance of the measured object and management requirements (I, II, III, IV, V).
• Class I energy metering devices include 220kV and above trade settlement energy metering devices, while 110kV trade settlement energy metering devices belong to Class II.
• Class II electrical energy metering devices include devices that measure the power generated by a single generator with a capacity of 100MW to 300MW.
• Class III energy metering devices do not include 380V-10kV energy metering devices.
• Class IV electricity metering devices do not include 220V single-phase electricity metering devices.
• Class V energy metering devices do not include 10kV - 110(66)kV assessment energy metering devices.
• Different categories of electrical energy metering devices have different accuracy requirements for the energy meters and transformers they use.
• In class I energy metering devices, the accuracy class for active energy meters is 0.2S.
• The voltage drop in the secondary circuit of voltage transformers in energy metering devices doesn't exceed 0.2% of the rated secondary voltage.
• For energy metering devices connected to neutral-grounded systems, three-phase three-wire active and reactive multifunction energy meters must be used.
• Voltage transformers in non-neutral-grounded systems should ideally be connected using the Yy method, with the primary-side grounding method consistent with the system grounding method.
• In three-phase three-wire electrical energy metering installations, the secondaries of the two current transformers and the electricity meter should be connected with four wires.
• In a 3/2 circuit breaker connection, the 2 current transformers involved in "summing" should have the same accuracy class, model and specifications.
• In low-voltage power supply scenarios, if the calculated load current is above 60A, current transformers should be used to connect the energy meter in order to provide the power.
• The maximum current for direct connection energy meters should not exceed 100A.
• Energy metering devices for trade settlement ought to be installed at a site where property rights are clearly defined.
• Trade settlement energy metering devices connected via transformers must be equipped with dedicated voltage and current transformers or dedicated secondary windings, and ought not to be connected to equipment unrelated to electrical energy metering.
• Energy metering devices with dedicated voltage and current transformers or secondary windings should have dedicated secondary wiring boxes and test wiring boxes.
• First-class energy metering devices ought to include primary and backup energy meters.
• The secondary circuits of voltage transformers for trade settlement energy metering devices above 35kV should be equipped with rapid automatic air switches, but not isolating switch auxiliary contacts.
• For trade settlement energy metering devices installed at electricity users' locations, those supplied with 10kV and lower voltages ought to be equipped with electrical energy metering cabinets or boxes conforming to relevant regulations.
• The shape and installation of energy meter screens in substations ought to comply with GB/T 7267 - 2015.
• Trade settlement energy metering devices are to have voltage loss timing capabilities in accordance with DL/T 566 - 1995 requirements.
• Connecting wires for electrical energy metering devices should use copper single-core insulated wires.
• When determining the rated primary current for current transformers, the actual load current during normal operation ought to reach around 60% of the rated value, and at the lowest it ought to be no less than 30%.

Short Answer Questions

• The purpose of DL/T 448-2016 focuses on power generation, transmission, distribution, and electricity use for trade settlement and economic-technical assessment, while management of energy information collection is based on these procedures.
• Electrical energy metering device technology management ought to adhere to the "Measurement Law of the People's Republic of China", the "Electric Power Law of the People's Republic of China", and other pertinent laws and regulations to ensure the accuracy and dependability of electrical energy measurements.
• The key aspects of electrical energy metering device technology comprises of various stages, starting from creating metering plans to the final disposal of old equipment, and other management tasks
• Grid companies need to set up management systems, define responsibilities, oversee supply business, develop measurement standards, conduct testing, handle issues, ensure safety, and educate personnel.
• Power plants creates rules, uses energy standards, collaborates, oversees all energy equipment (besides trading), and evaluates effectiveness.
• Power supply companies follows policies, creates local rules, plans for upgrades, creates standards, runs tests, engages in projects, ensures safety, and handles paperwork.
• Electrical energy metering is split into five classes (I, II, III, IV, V). Class I covers high-voltage deals and significant power generation.
• All types of electrical energy measuring devices measure voltage through a voltage divider. The voltage drop must stay inside 0.2% of the voltage dividers range.

Multiple Choice Questions

• A. B. C. D. E, DL/T 448 - 2016 "Technical Management Regulations for Electricity Measurement Devices" is applicable to trades, infrastructure, and power distribution in the electric power system.
• A. B. Under the normative citation instruments, the regulations for measuring machines require part 11.
• A. Under the regulatory citation and conformity file, the regulations that the electric power metering and machinery equipment technical administrations must abide by and be in line with includes measurement and electricity requirements.
• Ensuring the values are precise, the transfer of energy, and device safety are the goals of electric power measuring.
• A. B. C. Electrical engineers must be employed to establish a method of measurements on the grid system from a source that follows the best practices.
• Classes for energy needs and managing processes is how power measurement equipment is divided into classes, so the first kind is with the big power trading and high power for the grid system.
• A: By right of the measuring laws established by various nations to measure the validity and stability of the machines.
• B. For a class II electricity measurement, there was no obvious measure of what an inactive meter would be able to handle.
• Both B and E The right machines are being measured for various situations if the measurements to record the voltage, electricity, and capacitance are working properly.
• A, E; The two different connection types are defined in regulations and rules for both non and normal power sources.
• D; For low voltage equipment, power must be available if currents are at at least 60A
• There must also be the right instruments, or the test must have to be set out for that class of measurement.
• A grid system's best practices are needed for construction so there can be valid processes that are always being set.
• C. You will then want to make sure there is an assistant so every part can then run properly before the work is completed right.
• D. Be right the make of everything by being valid.
• A, C, E. When measuring power from places. the meters have to all work right in what is made for all systems.
• A. Under best practices, a system needs all of these systems under the code to work.
• A, E The main rule to test and follow is to fix the error immediately.
• A. For a grid system, one must also use one part and the greatest tech in this area to help make sure everything is working.
• One must also think how many are needed in the machines so everything can run well under a meter.
• B, C E. As a business that does power measurements, it must also see all types of machines for this to work under a business.
• A, C, D, and E are all needed to measure machines.