Technical management of self-provided power supply

introduction

The continued rapid economic development and the widening gap between electricity supply and demand have created a natural space for the self-provided power supply system to display its "talent". However, this has also brought many shocking safety hazards and even accidents! Recently, many media, including CCTV, have repeatedly reported that during the power supply interruption, some enterprises or users "talked about everything" and caused self-provided power supplies to reversely send electricity to the public power grid, resulting in personal injury accidents. Before the two power outages in 2006 and 2007, power supply and regulatory agencies at all levels in various places also repeatedly announced that all enterprises and units with self-provided power supplies should register with the local power management department within a limited time in accordance with the "Electricity Law of the People's Republic of China" and the technical regulations of the power industry, so as to be included in the safety management and prevent the self-provided power supply from reversely sending electricity to the power grid. However, some self-provided power users turned a deaf ear to the painstaking warnings of the power supply and management departments. Once the self-provided power supply reversely sent electricity to the power grid, causing a personal accident to the user, the self-provided power supply unit was very secretive about the accident, and the power supply unit was also afraid of "getting burned" and was afraid to avoid it. The occurrence of this phenomenon should not only be taken seriously by power workers, but also be given serious consideration by our self-provided power supply users.

Strengthen technical management of users with their own power supply

1) The self-provided power switch (circuit breaker) and the working power switch (mains power supply, public power grid) should be set up separately. Users must not combine the two to save costs. During the operation of the self-provided (working) power supply, at least one obvious disconnection point should be set between the self-provided (working) power supply system and the working (self-provided) power supply system in all aspects. For example, setting up a set of isolation switches (commonly known as setting up a set of isolation switches) and pulling open the set of isolation switches is an important technical link to prevent the self-provided power supply from sending power back to the power grid.

2) Technical measures should be taken to ensure that the backup power switch cannot be put into operation until the working power switch is shut down. Or the working power cannot be switched into operation until the backup power is shut down. A mechanical interlock should be set for the manually operated switch, and an electrical or logical interlock should be set for the electrically operated switch, such as: the closing circuit of the backup power switch is connected in series with the normally closed auxiliary contact of the working power switch to achieve this.

3) In order to ensure the safe operation of the load, under normal circumstances, the backup power supply should restore the operation of power-consuming equipment one by one after the rated voltage is established, and it is prohibited to increase the voltage of the backup power supply from zero with load.

4) In order to shorten the power outage time, you can set up a dual power automatic switching device (or a backup power automatic input device). However, the quality of such equipment on the market varies. You should choose products with reliable quality assurance, approved by the power product technical supervision authority, and allowed to be connected to the grid to ensure the safety of equipment and personnel.

5) If a dual power automatic switching device is installed, when neither the working power nor the backup power is in operating condition, it is necessary to ensure that any power switch will not automatically close. However, after any power is in operating condition, it can only be put into operation through human operation to prevent the sudden pressure of the equipment from threatening other workers in the load circuit. At the same time, a voltage monitoring device for the working power and the backup power should be installed.

6) The backup power supply must have sufficient capacity and a certain degree of redundancy relative to the total load to ensure the smooth startup of large-capacity loads.

7) If power is lost due to a short circuit in the load circuit or other faults that cannot be eliminated in a short time, ensure that the backup power supply will not be automatically put into operation to prevent the accident from escalating.

8) Only one backup power supply can be set for one load, and several backup power supplies cannot be set to prevent asynchronous parallel connection from causing damage to power supply equipment!

9) The protection device of the backup power supply should be scientific and reasonable, and the protection action value should not be set too large to ensure that the self-contained power supply can operate stably for a long time.

1O) Before and after the self-provided power supply is put into operation, the local power production and dispatching agency must be informed in a timely manner to facilitate the handling of emergencies.

11) Safety inspections should be conducted on users with self-provided power supplies and backup power supplies. The use of self-provided power supplies should be carefully reviewed. The application and acceptance procedures of the user's self-provided power supply should be carefully examined. Whether the necessary mechanical interlocking measures to prevent reverse power transmission have been taken, whether the operating rules and regulations are complete, whether the user's on-duty personnel are certified, and whether the user's on-duty personnel are qualified and capable. Measures should be taken for users who do not have the conditions for safe electricity use and rectification should be made within a time limit. Electricity management personnel should regularly inspect users of self-provided power supplies, promptly discover and deal with problems, especially unsafe factors, which should be rectified within a time limit. Violations of the "Electricity Agreement for Self-provided Power Customers" should be stopped in a timely manner and dealt with seriously in accordance with relevant regulations, and records should be kept.

12) The power grid management agency should control the installation, grid connection and operation of the user's self-provided power supply, and strictly implement the relevant regulations on the use of self-provided power supply (backup) power supply. All users with self-provided power supply (backup) power supply must apply to the power supply enterprise and sign an agreement before putting it into operation, and must install safety devices (such as locking devices, etc.) to prevent power from being sent back to the grid. All power supplies that need to be connected to the grid must sign a "grid connection agreement" with the power supply enterprise in accordance with the law before they can be connected to the grid.

13) Strengthen daily safety management and supervision of users with self-provided power supply and backup power supply. Establish complete user archives and data, which are fully reflected in the electrical primary system diagram and circuit diagram. Supervise users to conscientiously implement the relevant national and industry laws, regulations and rules on electricity, guide users to establish and improve basic data such as equipment maintenance and operation records within the scope of property rights, and formulate relevant systems to ensure the correct commissioning and shutdown of self-provided power supply and backup power supply.

14) Strictly implement the "Electric Power Safety Work Regulations", conduct risk point analysis, and conscientiously implement technical measures such as power outages, power testing, and grounding wires. For work that requires power outages, especially disconnect the circuit breakers and isolating switches that may reverse (return) the low-voltage power supply, hang a sign that reads "Someone is working on the line, do not close the switch", and short-circuit grounding wires must be hung on the branch lines that may supply power to the power-off line. Short-circuit grounding wires must be hung on both sides of the work site to effectively prevent personal electric shock accidents caused by back-feeding.

Strengthen legal education

First, public media and power news agencies should strengthen the publicity of the "Electricity Law of the People's Republic of China" and the "Power Supply Business Rules" to make large users understand the principle of "multiple power companies, one company to manage power". The power supply department should sign power supply contracts with users with self-provided power supply systems to establish liability for breach of contract. All unauthorized access (supply) of power or self-provided power and other power sources to the power grid without the consent of the power supply enterprise are illegal and must be strictly stopped. Secondly, in the power supply and use contract, important users and power supply enterprises should clearly define the important user access system plan, the property rights division between the power supply and user, the operation and maintenance responsibilities of power supply and use facilities, the safety management responsibilities, the backup power supply and emergency power supply configuration, and the non-electrical security measures in the event of power supply interruption. In addition, in the grid connection dispatch agreement, important users and power supply enterprises should clearly define the responsibilities and rights of both parties, grid connection conditions, grid connection methods, load management, equipment operation and maintenance management responsibilities, emergency handling procedures, effective communication methods, and the qualifications and safety responsibilities of the operation and duty personnel of important users. The administrative department in charge of electric power shall supervise and inspect the safe power supply and use behaviors of important users in accordance with the law, accept complaints from units and individuals, and investigate and punish illegal power supply and use behaviors in accordance with the law.

in conclusion

Due to the continued rapid development of my country's economy, the power supply is still unable to meet the ideal requirements of the majority of users during some periods of time. This requires both supply and demand sides to cooperate with each other, overcome "difficulties" together, and work together towards a bright future.