Papers on distribution management

1 Problems existing in current low-voltage distribution management

1. 1 technical problems

These problems are mainly reflected in the following points:

① High low voltage line loss;

(2) outdated equipment;

(3) The electricity meter is difficult to prevent electricity theft, and its function is not strong;

④ Three-phase load is unbalanced.

1.2 problems in management

There are mainly the following problems in management:

(1) line loss work is not up to standard;

(2) Inadequate maintenance of lines and equipment;

(3) The phenomenon of illegal electricity use and electricity theft is poorly managed.

With the rapid development of China's economy, the electricity consumption in urban and rural areas is increasing day by day, which puts forward higher requirements for our low-voltage distribution management. Based on many years' working experience, the author puts forward a set of low-voltage distribution management ideas and discusses this problem from three aspects.

2 Low-voltage distribution management measures

2. 1 for scientific management

To achieve the goal of scientific management, we need to start from the following aspects:

2. 1. 1 Establish a scientific and reasonable management system. Establishing a reasonable low-voltage distribution management system can manage all stations involved in the power grid in a unified way. At the same time, it is necessary to clarify the division of responsibilities of managers and put them in place to ensure that low-voltage distribution management has rules to follow and laws to follow.

2. 1.2 establish a regular meter reading system, implement dynamic meter reading management, and check the measurement summary table and sub-table synchronously on a regular and irregular basis.

2. 1.3 Strictly guard against stealing electricity and strengthen the supervision of electricity consumption. As the staff of the grass-roots power grid, they should abide by the electricity consumption system, strengthen publicity based on the system, and advocate the vast number of users to use electricity in a civilized manner and according to law.

2. 1.4 in order to ensure the normal operation of power supply equipment, the electricity consumption should be detected and recorded in detail to prevent the occurrence of electricity theft and illegal use, and severe sanctions should be imposed on those that have occurred.

2. 1.5 Strengthen demand side management, correctly guide the operation and maintenance management of customers' electrical equipment, and ensure economic operation. Pay attention to the economic operation of low-voltage distribution transformers. For seasonal or temporary distribution transformers, a corresponding number of loads should be connected according to the capacity of the distribution transformer before it is put into operation, so as to ensure the most reasonable load rate, the highest efficiency and the lowest energy consumption of the transformer.

2.2 "standardized" transformation of cities and towns

At present, the city is carrying out the county power grid reconstruction project, which provides us with a rare opportunity to reduce line loss, and low-voltage transformation is also the most direct embodiment of the benefits of power grid transformation. The following purposes need to be achieved through power grid transformation: First, master the law of power loss in the power grid under our jurisdiction; The second is to find out the ratio of technical line loss to management line loss, so as to provide theoretical basis and data support for future practical work and planning management; The third is to detect the loopholes in the power grid and determine the focus of power grid transformation in the future; The fourth is to find out the problems existing in the operation of the power grid, formulate the best operation plan, and make the loss reduction measures targeted; The fifth is to find out the reasons for the rise and fall of line loss and work out the general working direction.

2.3 Standardize meter reading management and replace new meters.

To eliminate the old watt-hour meter, a new watt-hour meter with small error, strong overload capacity, anti-tilt, anti-theft and automatic meter reading management should be adopted. Popularize and apply centralized meter reading system to realize remote meter reading for large users and residents.

3 Low-voltage distribution network construction

3. 1 technical point

3. 1. 1 The low-voltage distribution network shall adopt a radial structure centered on the low-voltage distribution room with low-voltage distribution cabinets. Leakage protection device, fuse, low-voltage circuit breaker, etc. It can be installed between transformers, which can protect the low-voltage distribution line from supplying power to users normally after a fault occurs.

3. 1.2 it is suggested that the distribution equipment should be in the form of low-voltage distribution room or outdoor distribution box, in which all user meters, meters' incoming line side switches and leakage protectors are installed.

3. 1.3 standardize the incoming and outgoing lines. The incoming line adopts special power cord, which is different from the incoming line of users. Incoming lines and feeder lines are crimped, and incoming lines are concentrated in the low-voltage junction box or directly into the distribution room and junction box in the distribution box.

3. 1.4 For the configuration of low-voltage compensation, the combination of fixed compensation and decentralized compensation is needed to compensate the lost low-voltage capacitance.

3.2 Comprehensive analysis

The benefits of centralized wiring are obvious, because the number of branch lines is reduced and the connectors are centralized, which is convenient for the maintenance of power maintenance managers and greatly enhances the safety of electricity use. At the same time, this form can also make each branch line bear the charge evenly, which is convenient for adjusting the load distribution. It can be adjusted according to the load situation, so that the three-phase load can be balanced as much as possible, and the waste of resources and even safety accidents caused by excessive load on some lines and insufficient load on some lines can be avoided.

The purpose of using low-voltage distribution cabinets or outdoor distribution cabinets is to uniformly manage metering devices. For grass-roots power managers, it is convenient for meter reading and maintenance, saving time and improving efficiency. At the same time, we can also have the opportunity to promote the application of centralized meter reading system to realize remote meter reading for large users and residents.

4 Distribution Management System (DMS)

4. 1 overview

Power distribution management system is a computer network system involving operation management, equipment management, user service and other aspects of power supply enterprises. Based on the real-time environment of distribution automation, geographic information system and comprehensive database system, several relatively independent application function subsystems are formed, including distribution automation (DA), distribution work management (DWM), fault complaint management (TCM), automatic drawing (AM) and equipment management (FM), load management (LM) and distribution network analysis system (DAS). In order to realize the automation of distribution network management, optimize the operation of distribution network, improve the reliability of power supply and provide quality services for users.

In some developed countries, DMS has been paid more and more attention. It is defined as an automation system that enables power distribution enterprises to monitor, coordinate and operate power distribution equipment in real time. China's distribution automation has also made great progress, the main signs are:

① The host system has developed from an eight-bit machine to a sixteen-bit machine;

② The system function has developed from SCADA system to practical function;

③ Improve the accuracy and reliability of primary and secondary equipment to realize unattended substation;

④ The organizational management system is more suitable for the electricity market.

4.2 Functions of Power Distribution Management System

The distribution management system (DMS) has quite powerful functions, which are briefly introduced below.

① Distribution automation DA. Realize the operation, monitoring, fault diagnosis, fault isolation and network reconfiguration decision of distribution network.

② Load management LM. Provide large user load collection and control functions.

③ Fault complaint management. Complaint telephone handling, fault location and power supply restoration.

④ Distribution network analysis system DAS. Network modeling and network topology, state estimation, distribution power flow, network loss and voltage drop analysis, short-circuit current, voltage/reactive power control, load forecasting, etc.

⑤ DWM of distribution management. Distribution network operation and statistical report management; Distribution design, construction and maintenance management.

⑥ Drawing Management AM/FM/GIS Distribution Drawing Management System is an automatic drawing (AM) and equipment management (FM) system based on GIS. It takes the street geographical location marked with various power equipment and lines as a powerful tool for the distribution network to manage and maintain power equipment and find and eliminate equipment failures.

Generally speaking, the advanced application software of DMS is mainly developed at three levels:

① Basic application software (network topology, state estimation, power flow calculation, etc.). );

② Derived application software (such as substation load distribution, feeder load distribution and phased load balance);

③ Professional application software (such as residential load forecasting, complaint hotline handling, transformer equipment management, etc.). ).

In a word, DMS is a new field and an indispensable part of integrated automation of power system. It plays an extremely important role in the safe, stable and economic operation of power system and is an important development direction of power system. In the process of implementing the distribution management system, we should pay attention to the following issues:

① Plan the primary system of distribution network and distribution system, and choose the implementation scheme according to local conditions;

(2) consider EMS. DMS and so on. From the perspective of informatization, try to enjoy information resources by using computer network technology;

(3) Strengthen the development of distribution automation communication technology and equipment and the standardization of protocols;

④ Pay attention to the characteristics and requirements of distribution network application software.

5 concluding remarks

Low-voltage distribution management involves many problems. According to the actual situation, we need to adopt advanced computer technology and management concepts combined with practical experience to continuously improve management, improve the management level of low-voltage distribution, and create more social value for the country, society, electric power and people.

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