In recent years, with the acceleration of the industrial process in China, the power construction and the amount of electricity used have increased. As a result, the construction of substations has increased, and higher demands have been placed on the power sector in China. As an important part of the substation electrical equipment, the quality of the installation has become the key to the normal operation of the substation, and the installation technology directly determines the installation quality of electrical equipment. At present, many substation projects in China are not well-developed due to the lack of experienced on-site technicians or installation techniques during the construction process, causing many problems in the installation of electrical equipment. Therefore, reasonable and feasible installation methods and skilled installation techniques have become an urgent need for current substation projects. Based on this, the author combines many years of experience, conducted an in-depth discussion on the technical points of electrical equipment installation, hoping to provide reference for the future installation of electrical equipment in substations. 1 Overall arrangement of electrical equipment installation procedures in substations After the preparatory work for substation electrical equipment is completed, the electrical equipment can be installed according to the following construction procedures: 1.1 Once high-voltage equipment is installed Primary equipment includes switching equipment (such as transformers, current transformers, control equipment) (such as high and low voltage switchgear, protection equipment (arresters, etc.), compensation equipment and complete sets of equipment. After the adjustment of the primary equipment foundation, conduct the installation adjustment test and equipment connection, and then perform the main transformer and auxiliary equipment installation and adjustment test. 1.2 Low-voltage equipment and power compensation device When the low-voltage equipment is installed, the indoor high-voltage switchgear shall be installed and commissioned before installing the outdoor bus bridge. When installing the power compensation device, the installation and adjustment tests of the reactor and the shunt capacitor shall be conducted first. Then, the hard bus bar shall be connected and the high voltage cable head shall be installed. Finally, the gate of the gate shall be installed. 1.3 Installation of secondary equipment and relay protection The secondary equipment includes power meter, voltmeter and protection relay. The secondary disk and cabinet shall be installed first, then the cable shall be laid, and the secondary wiring shall be conducted. In the relay protection commissioning, the protection component is debugged first, then the line-to-line inspection is performed, and the entire group of simulation tests is performed. 1.4 High-voltage equipment test Transformer, transformer, circuit breaker, disconnector, arrester and other equipment tests. 2 Problems Occurring during Installation of Electrical Equipment Electrical equipment plays a vital role in substations and directly affects the safe and stable operation of substations. However, in the process of construction and installation of many substations in China, due to the lack of experienced on-site technical personnel, unskilled installation technology, or technical personnel considering incomplete problems, etc., many problems have arisen during the installation of electrical equipment. 2.1 The size of the transformer installation on the site does not match the size of the current, the domestic transformer is generally installed in the base steel welded with the grounding Thousand-line, with transformers and other bolts fixed on the steel seat. Transformer installation requirements are high, and problems such as mismatched sizes of steel bases and transformer chassis and cabinets often occur. 2.2 During the installation process, due to the careless operation of the construction staff, the installation of the instrument and other electrical equipment should be carried out in strict accordance with the drawings of the design documents. In actual installation, equipment such as meters are often inadvertently knocked by technicians, vibrated or abnormally impacted by external forces, and the equipment and line pipes are connected unevenly and are not subjected to forces, resulting in insecure equipment installation. When certain electrical equipments are installed in dusty and humid places, they have not taken corresponding sealing precautions, thus affecting the connection of equipments and lines and causing major problems. 2.3 The cable protection measures are not laid under the ground like a full cable. When laying, it is necessary to pay attention to waterproof and moisture, and take relevant protective measures to strictly manage the pipe hole to ensure the safe operation of electrical equipment. However, in the actual installation of the cable, the hole of the pipe is often not leaked due to the strict management of the pipe hole, causing hidden troubles such as water accumulation in the cable ditch, so that the cable is destroyed, thereby affecting the normal power supply of the substation. 3 Technical Points for Installation of Electrical Installations in Substations 3.1 Main Transformer Installation Technical Points The main transformer is the main equipment of the substation and plays a decisive role in the safe operation of the substation after commissioning, due to the complexity of the installation process and its role in the entire electrical equipment. Because of its importance, the technical requirements for transformer installation are very high. Before installation, it is necessary to carefully inspect the insulation strength and sealability of the various components of the power transformer. During the installation process, professional on-site construction personnel must strictly follow the rules and regulations, transformer product technical specifications and construction procedures. If any problems are encountered in the installation process, they should be dealt with promptly and respond well to prevent potential safety hazards from occurring. Before construction, construction drawings and construction technical data must be prepared. According to site conditions, on-site supervision should be made to ensure that the civil engineering drawings and electrical installation drawings are consistent. During the installation process, the installation procedure and the debugging content of the transformer must be determined, and the insulation performance before installation must be checked. Specifically, there are three issues that should be noted: 1) The basic track of the transformer should be horizontal, and the track and track should be matched. 2 After the transformer is in place, the transformer fixing device and the base should be welded firmly, and the transformer body should be reliably grounded. 3) The top cover of the transformer equipped with a gas relay must have a gradient of 1% 1.5% in the direction of the gas relay. Technology R&D Technology and Market 3.2 Circuit Breaker Installation Technical Points Before installing the circuit breaker, it is necessary to ensure that the circuit breaker and the operating mechanism are correctly assembled according to the assembly instructions. All bolts are tightened according to the torque required by the assembly instructions, and all the units are in an open and closed state. The correct wiring of the circuit breaker control loop disconnection is caused by the closing position relay and the normally closed contact of the trip position relay in series to form the disconnection signal of the circuit breaker control loop. In addition, in order to prevent the circuits from tripping during tripping, the closed contacts of the circuit breaker mechanism box should also be connected to different power circuits. 3.3 Isolation Switch Installation Technical Points The connection between the cable and the overhead line, the power supply side of the circuit breaker, the position of the branch line T, the position between the overhead lead-off line and the drop switch, and the contact between the overhead line T and the user's power cable Point, these places must install high voltage isolation switch. In the installation process of the isolation switch, pay attention to the appropriate force, so as not to cause the internal gear does not match, resulting in different phases of the three-phase current. When installing and adjusting the contacts, special attention should be paid to the contact problems of the moving and static contacts, so that the depth of insertion is good, the contacts are completely in contact, and the phenomenon of heat generation is prevented from occurring; in addition, attention should be paid to the adjustment of the grounding knife and the application of lubricant to the movable contact. For the contacts, care should be taken to clean them in time. The surface of the contacts should be polished to make it flat and ensure good contact. 3.4 Installation Technical Points for Cable Lines Installation and installation of power cables requires consideration of safety issues and environmental constraints. Before installation, according to the specific conditions of the construction site to design drawings and construction in strict accordance with the drawings, but also should pay attention to check whether the cable meets the specifications, whether the cable core moisture, etc., must also ensure that the installation of various materials and tools are complete. During the installation of the cable, the plastic sheath shall be intercepted from the length of the cable bracket to the electrical connector, and the relevant marking work shall be done; the outdoor cable shall also be protected from moisture and rain, and if necessary, the protection cable of the power cable may be used. In addition, the following points must be noted: The power cable is different from the insulated wire, and its heat generation and heat dissipation are difficult. Therefore, compared with the power cable with the same diameter and the insulated wire, the current carrying capacity is much smaller. 2 The ampacity of the cable must strictly meet the requirements in the manual and must not be allowed to operate at full capacity. 3 When the wire is expanded, the parallel running cables must be laid so as not to exceed the upper bound of the cable current carrying capacity. 3.5 Installation Technology of Suspended Tubular Busbars The suspended tubular busbars must be welded before installation. To avoid the decrease of the strength of the busbars at the welded joints, reinforcement measures should be taken in the welding position. Before the welding, the weld surface on both sides of the bevel should be cleaned. The welding speed should be uniform to ensure the welding quality. For the joint part, the beveling machine should be used to ensure smooth, uniform and burr-free groove. Before the porcelain bottle is installed, it should be ensured that the appearance of the porcelain bottle is smooth and the connecting hardware meets the design requirements. During the installation process, string vases and connecting hardware shall be assembled strictly according to the construction drawings, and the length of the design shall be ensured. Then, the lengths of the two basket screws shall be adjusted to the middle position. In order to prevent deformation of the hanging type tubular bus when lifting, the pipe bus should adopt a multi-point lifting method. That is, the tube mother is hoisted to the appropriate height, then the suspension insulator string is pulled to the clamp position, and then assembled. 4 Conclusion In summary, electrical equipment as an important part of the substation, its installation technology and quality directly affect the safe operation of the substation. Combining years of working experience, the author briefly discusses the problems involved in the overall arrangement of the electrical equipment installation process in the substation and the equipment installation process, and also deals with transformers such as main transformers, suspended tubular buses, circuit breakers, disconnectors, and cable lines. The main technical points for the installation of electrical equipment are discussed in depth and have certain practical significance. I hope that through this article, I can provide some reference for future installation of electrical equipment in substations. Tensile Testers,High Quality Tensile Testers,Tensile Testers Details, CN Dongguan Huitong Automatic Machinery Technology Co., Ltd , https://www.breezesolution.com