One article to help you understand substations, switchgear rooms, power transformation stations, distribution rooms, box-type transformers, and voltage transformation stations!

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One article to help you understand substations, switchgear rooms, power transformation stations, distribution rooms, box-type transformers, and voltage transformation stations! Substation Definition: A substation is a place where voltage is changed. In order to transmit the electricity generated by power plants to distant locations, the voltage must be increased to high levels; it is then reduced as needed near the consumers. This process of increasing and decreasing voltage is carried out by substations. The main equipment in a substation are switches and transformers. Depending on their size, the smaller ones are called substations. A substation is larger than a transformer station. Substation: Generally refers to step-down substations with a voltage level of 110 KV or less; Substation: Includes \"step-up and step-down\" substations of various voltage levels. A substation is a power facility in the electrical system that is used for voltage transformation, receiving and distributing electrical energy, controlling the direction of electricity flow, and adjusting voltages; it connects power grids at different voltage levels through its transformers. The substation is located in a specific environment; it performs the AC-DC-AC conversion process. Such as undersea power cables and long-distance transmission. Some use high-voltage DC transmission and transformation. DC transmission overcomes the capacitive reactance losses of AC transmission. It has an energy-saving effect. Substations are primarily used for converting high voltage to medium voltage, or high voltage to a level slightly lower than high voltage. They require a large amount of space, with the required area varying depending on the voltage level and capacity. That’s why some people call it a substation... Location: From the perspective of power supply efficiency, substations should be located near the load centers. From a production perspective, substation areas should not hinder production and internal transportation, and the transportation of equipment within such substation areas should also be convenient. From a safety perspective, substation areas should be kept away from flammable and explosive locations. The substation should be located on the upwind side of the facility. In enterprises, it should not be installed in areas where dust and fibers tend to accumulate. Substations should not be located in densely populated areas. The location and design of the substation building should also take into account the requirements for fire suppression, corrosion prevention, pollution prevention, water resistance, rain protection, snow protection, earthquake resistance, and prevention of small animals from entering. (Standardization note! ) Function: A substation is a transitional device that connects power plants to users. Since power plants are located very far away from the cities and factories that use electricity, and the voltage generated by these plants is not high, the current becomes very large. According to Joule’s law, such a large current generates a lot of heat in the transmission lines, which can lead to damage to those lines. Moreover, converting current into heat represents a loss as well. Therefore, it is necessary to increase the voltage at the power plants to 500,000 volts using substations, so that the electricity can be transmitted over long distances to the cities and factories where we live. Once there, the voltage is reduced again through local substations, and through various distribution methods, it is brought down to the usual 220 volts used in our daily lives. Substation Definition: A substation is a place where voltage is changed. It is a place in the power system where the voltage and current of electrical energy are transformed, centralized, and distributed. To ensure the quality of electrical power and the safety of equipment, voltage regulation, current control, as well as the protection of power transmission and distribution lines and major electrical equipment are also necessary in substations. By purpose, they can be divided into power substations and traction substations (for electric railways and trams). According to the terminology defined in the **standard GB50053-94 \"Design Code for Substations of 10 kV and Below\", it is stated that a substation is one in which \"an AC power supply of 10 kV and below is used to supply power to electrical equipment after being stepped down by a power transformer\"; facilities that meet this definition are considered substations. Function: The role of a substation is to take the electricity generated by power plants, whose voltage is usually no more than one or two thousand volts. If this electricity is transmitted over long distances directly, the current in the transmission lines will be very high, resulting in significant energy losses in those lines, which is uneconomical; moreover, the power transfer capacity of such lines is low. Therefore, a transformer is used to raise the voltage to tens of thousands or even hundreds of thousands of volts (depending on distance and power), in order to reduce the line current. To connect power lines of different distances and capacities into a power grid in order to enhance overall safety, multiple substations are needed to link together lines of varying grades. Similarly, after high-voltage electricity is delivered to its destination, it needs to be stepped down to several levels such as 10,500V, 6,300V, 400V (i.e., 380/220V) in order to meet the needs of different users. That’s why so many substations are needed in practical applications. A main substation generally refers to a primary transformer, with secondary transformers under it. The function of the primary transformer is to switch high-voltage power distribution; it is not responsible for voltage transformation. Power distribution room Definition: A power distribution room is also known as a substation. According to **the standards, a substation is defined as a facility that contains only high-voltage power distribution equipment used for switching and distributing electrical energy, with no main transformers on the busbars. The voltage level in the power distribution room is below 35 KV, and it is equipped with switches, transformers, capacitors, as well as related protection and measurement devices. Put simply: build a structure, place transformers inside it, along with incoming and outgoing cable cabinets, and that constitutes a power distribution room. In larger facilities, there are multiple transformers, high-voltage cabinets, low-voltage cabinets, and various other components, forming an independent space or area within a building dedicated to transforming and distributing electrical energy. The difference between a distribution station and a substation is that a distribution room (distribution station) does not have transformers, while a substation has transformers. Substations and power distribution rooms mainly refer to the facilities for voltage transformation and power distribution in residential complexes or buildings, etc. The power distribution room is a crucial part of a building’s power supply system, and a dedicated electrician is assigned to monitor it on a 24-hour basis. Without the permission of the management manager or department head, non-staff members are not allowed to enter. The duty officer must work with a valid certificate, and be familiar with the condition of the power distribution equipment, its operating methods, and safety precautions. The duty officer must pay close attention to the readings on the voltmeter, ammeter, and power factor meter; it is strictly prohibited to operate the air switch under overload conditions. Keep the floor of the power distribution room and the exterior of the equipment free of dust at all times. The switching operations of equipment in the power distribution room are carried out solely by the duty officer, with other people present acting only as supervisors and not interfering in any way. It is strictly prohibited for two persons to carry out switching operations simultaneously to avoid errors. The difference between a public power distribution room and a dedicated power distribution room is as follows: 1. In terms of authority, a dedicated power distribution room is managed independently by the property owner ； Public distribution rooms are under the management of the power supply bureau. 2. In terms of load distribution, the load supplied by the dedicated power distribution room is used to power the public facilities and equipment within the community, such as fire pumps, domestic water pumps, fans, elevators, public lighting systems, as well as various commercial facilities ； The load supplied by the public distribution room is intended solely for residential electricity use. Substation Definition: A substation is a distribution facility that enables the opening and closing of circuits using switching equipment, without any voltage transformation. It is a power facility that supplies high-voltage electricity to several nearby consumer units, and it sits at the next lower level in the power system hierarchy compared to substations. It is characterized by the same voltage on the power inlet side and the outlet side. Of course, regional substations also have the function of an outdoor switchyard. However, it should be clarified that a switching station is distinct from a substation. A substation also refers to a power supply and distribution facility used to receive and distribute electricity; in high-voltage power grids, it is known as a switchyard. Switching stations in medium-voltage power grids are generally used for the reception and distribution of 10kV electricity. Switchgear stations typically have two inputs and multiple outputs (usually 4 to 6 outputs), and depending on the requirements, circuit breakers or load switches can be installed for the inputs and outputs. It is a fully metal-enclosed switchgear assembly capable of operating outdoors at voltage levels below 10 KV. The transfer capacity is around 8000 KW, providing medium-voltage power to the substation or distribution rooms in a particular area. Location: Installed near stations, freight yards, electric locomotive depots, hub stations, and other locations with high power demands. Function: Divides the power supply arm into segments, reduces the scope of an accident in case of a fault, and improves the reliability and flexibility of power supply ； Reduce the complexity of substations ； Without changing the voltage level, simply increasing the number of feeder circuits is equivalent to a substation. Box-type transformer (commonly known as box substation): Definition: A box-type substation, also referred to as a prefabricated substation or pre-assembled substation. It is a type of high-voltage switching equipment, distribution transformer, and low-voltage distribution apparatus that are combined into one unit according to a specific wiring scheme; it represents a compact indoor or outdoor distribution device manufactured in factories. It integrates functions such as voltage reduction by the transformer and low-voltage distribution into one system, and is installed within a fully enclosed, mobile steel structure box that provides protection against moisture, rust, dust, rodents, fire, theft, and heat. It is particularly suitable for the construction and renovation of urban power grids, representing a new type of substation that has emerged alongside conventional concrete-built substations. Generally, high voltage is converted to low voltage; for example, a 10kV line is transformed by a transformer into the 380V voltage suitable for use. Box-type substations are suitable for use in mines, industrial plants, oil and gas fields, and wind power stations. They replace the traditional concrete-built distribution rooms and substations, serving as a new type of integrated power transformation and distribution unit. A box substation (abbreviated as box sub) generally consists of a high-voltage compartment, a transformer compartment, and a low-voltage compartment. Substation boxes are relatively simple power conversion and distribution devices; the selection of their transformer components can be handled according to general guidelines, with a capacity generally not exceeding 1250 kVA. Temporary box transformer: A box transformer used on a temporary basis, such as the temporary transformer at a construction site, which is meant to be removed in the future and not intended for permanent use. Location: The first type is mainly used in residential areas and streets in cities during peak electricity demand periods. When an increase in voltage is needed, our equipment – the box substation – comes into use. The second type is mainly used for temporary power supply, such as at construction sites where existing buildings require the modification of electrical equipment. Box substations are also frequently used in field operations, such as construction sites, docks, airports, and so on. Function: Box-type substations are used in high-rise residential buildings, luxury villas, squares and parks, residential communities, small and medium-sized factories, mines, oil fields, as well as for temporary construction power supply, where they serve to receive and distribute electrical energy within the power distribution system. Traction substation: Definition – The function of a traction substation is to convert three-phase high-voltage alternating current at 110 KV (or 220 KV) into two-phase alternating current at 27.5 KV, which is then used to supply power to the catenary systems in both the upward and downward directions on the railway line (with a rated voltage of 27.5 KV). Each side of the catenary system supplied by a traction substation is referred to as a feeding arm. The voltage phases of the contact wires on these two arms are different, and they are generally separated by phase insulators. The catenary voltage between adjacent substations is generally in the same phase; in addition to being isolated using phase-separated insulators, sectionalizing boxes are also installed. By operating the circuit breakers or isolating switches in these sectionalizing boxes, two-sided (or one-sided) power supply can be implemented. Special substation for electric traction. The traction substation converts the electrical energy supplied by the regional power system into a form suitable for electric traction, in accordance with the specific requirements regarding current and voltage for such use. This converted energy is then sent either to the catenary lines installed along the railway tracks to power electric locomotives, or to the power supply systems required for urban transportation systems such as subways, to power electric vehicles or trams in those systems. An electrified railway is equipped with multiple traction substations along its length, with the distance between adjacent substations being approximately 40 to 50 kilometers. On long electrified railways, in order to divide the high-voltage transmission lines into sections and thus limit the scope of any faults, pillar traction substations are generally installed every 200 to 250 kilometers. In addition to performing the functions of a regular substation, these stations distribute the electrical energy supplied by the high-voltage grid to other intermediate substations through their busbars and transmission lines. Definition of sectional booth: Installed between two traction substations, it enables the adjacent catenary supply sections (the upper and lower sections of the same supply arm, or the two supply arms of two adjacent substations) to operate in parallel or independently. If a short-circuit fault occurs in the contact network of a certain section on either side of the substation, the feed line circuit breaker in the power supply traction substation and the circuit breaker in the substation can automatically trip under the action of relay protection, thereby isolating the faulty section of the contact network, while the contact networks in the non-faulty sections continue to operate normally, thus reducing the scope of the incident by half. Location: Located between two traction substations to enhance the flexibility and reliability of power supply. Function: Phase separation ； Inter-zone power supply ； Reduce the scope of the accident.