Electric substation

Electric substation

A substation is a place in a power system where voltage and current are transformed to receive and distribute electric energy.

The substation in the power plant is a booster substation, whose function is to boost the electric energy produced by the generator and feed it to the high voltage grid.

Classify:

(1) A class of substation. It refers to AC UHV stations, nuclear power and large energy bases (3 million kw and above) sending and connecting 750/500/330kV substations across large regions (North China, Central China, East China, Northeast China and Northwest China).

(2) Class II substation. It refers to other substations except the first class, 750/500/330kV substations, power plant transmission substations (1 million kW and above, 3 million kW and below) and inter-provincial contact 220kV substations, main transformer or bus outage, switch rejection resulting in power grid events of level 4 and above.

(3) Three types of substations. It refers to 220kV substations except Class II, power plant transmission substations (300,000kW and above, 1,000,000 kW and below), substations where main transformer or bus outage and switch rejection cause Level 5 grid events, and substations that supply power directly to primary and above important users.

(4) Four types of substations. It refers to the substation of 35kV and above except Class I, II and III.

Note: All 220kV substations in the work area are classified as three substations, and all substations under 110kV are classified as four substations.

Facility:

The electrical equipment in the substation is divided into primary equipment and secondary equipment.

The following is a brief introduction of the main equipment in the substation.

1. Primary equipment

Primary equipment refers to the equipment that directly produces, transmits, distributes and uses electric energy, mainly including transformers, high-voltage circuit breakers, isolating switches, busbars, arresters, capacitors, reactors, etc.

2. Secondary equipment

The secondary equipment of substation refers to the equipment for measuring, monitoring, controlling and protecting the operating conditions of the primary equipment and system. It mainly consists of relay protection device, automatic device, measurement and control device, measuring device, automation system and DC equipment that provides power for the secondary equipment.

The structural design and equipment layout of substation generally have the following requirements:

(1) The a attached 10kV substation at the bottom of the building does not need to be divided into rooms, transformers and high and low voltage switchgear can be arranged in the same floor and in the same room, only need to maintain a specific distance, 35kVindependent substation with a proprietary building should be arranged in accordance with the functional stratifications and ddivided rooms:

② The indoor layout of the substation should be compact and reasonable to facilitate the operation, maintenance, testing and inspection of the operator. The installation position of the switch cabinet should meet the minimum channel width requirements, and give due consideration to the requirements of development and expansion;

(3) The location of each function room in the substation should be rationally arranged. The high-voltage distribution room is adjacent to the high-voltage capacitor room, and the low-voltage distribution room is adjacent to the transformer room. The low-voltage distribution room should be convenient for outgoing lines, and the location of the control room should be convenient for the work and management of the operating personnel.

(4) The facilities of high and low voltage distribution rooms should meet the requirements of safety and fire prevention, and combustible materials are not allowed to be used in the station decoration;

⑤ The doors of high and low voltage distribution room, capacitor room and transformer room should be opened outward, and the doors of two adjacent distribution rooms should be opened bidirectional;

⑥ High and low voltage distribution room, capacitor room, transformer room and main control room should be set up to prevent rain, snow, snakes, rats and other facilities from the door, window and cable ditch.

Inspection:

Substation inspection is the duty personnel through regular inspection to observe the

appearance of the equipment has no difference, such as color change, there is no sundry, dial indicator is normal, equipment sound is normal, there is no abnormal smell, touch allowed contact equipment temperature is normal, measurement of electrical equipment operating parameters in the operation of changes, etc. To determine whether the running status of the equipment is normal.

The inspection system of substation is an effective measure to ensure the normal and safe operation of equipment. It is of great significance for reducing the occurrence and influence of accidents to understand the running condition of equipment, grasp the abnormal operation and take corresponding measures in time through the regular patrol inspection of the personnel on duty. To this end, the substation should work out specific inspection methods according to the actual operating conditions of the equipment, and summarize the experience and lessons of handling equipment accidents, obstacles and defects in the past.

The inspection system shall clearly specify the items and contents of inspection, the cycle and the route of inspection, and make clear signs. The route of inspection shall be determined according to the inspection items and contents of the equipment area and electrical equipment. If conditions permit, substations should be equipped with necessary inspection equipment. During peak load period, infrared thermometers can be used for inspection. In addition, adequate and good lighting should be ensured to provide necessary conditions for equipment inspection. In special patrols at night, in bad weather and during special tasks, specific patrol requirements and precautions should be clearly defined and necessary measures should be taken. The special patrols must be attended by leaders on duty. After each inspection, the inspected equipment defects shall be recorded in the equipment defect record book, and the inspection personnel shall be responsible for the records.