Discussion on the application of box type substati

Brief discussion on the application of box type substation in Urban Rail Transit Engineering Abstract: This paper introduces and analyzes the characteristics, interfaces, technical requirements and application of box type substation in urban rail transit engineering

key words: box type, substation, rail transit, application

I. Introduction

with the sustainable development of China's economy, urban rail transit has become the preferred means of transportation to solve the public transportation of large and medium-sized cities. Guangzhou, Shanghai, Shenzhen, Nanjing, Tianjin, Beijing, Chongqing and other cities have built/under construction projects, and other cities are in the stage of planning or preparation, The construction of urban rail transit in China is at a stage of rapid development. In large and medium-sized cities in China, whether subway or light rail, there are many problems, such as tight space, high civil engineering investment cost, tight construction period and so on. As the core of metro/light rail traction power supply system, traction substation has the characteristics of many types of equipment, large floor space and long design cycle. If the box type substation can be introduced into the construction of urban rail transit, it will undoubtedly reduce the scale of the station, make it easy to realize the landscape modeling of the station, reduce the demolition workload, save civil engineering investment, greatly reduce the amount of on-site cooperation, shorten the construction period, etc

II. Application of box type substation in the field of urban rail transit

at present, traction box type substation has been widely used in foreign power systems, urban rail transit and other fields. For example, 16 1500kW and 2500kw traction substations of Dallas light rail system in the United States are box type traction substations; In the E1 Cajon LRT line project of Santiago metro system, 12 1000KVA traction substations are also box type traction substations; In the Eastern Railway in operation in Hong Kong, two traction substations and one section post are box type substations, which were manufactured by the then British South Wales company (now incorporated into the UK FKI group) and have been in operation for nearly 20 years

in the Western Railway of Hong Kong, which will soon be put into operation, a traction substation, a section post and a switching post are all box type substations, which are supplied by Siemens of Germany and are expected to be opened in 2004. In China, due to the relatively late start in this area, some applications are relatively simple. Generally, the main equipment installed in containers are only distribution transformers and some supporting switches, with relatively simple functions. There are also some applications to varying degrees in some places, such as urban and rural buildings, residential quarters, small and medium-sized factories, mines and oil fields, as well as temporary construction power consumption places that will maintain a good development trend

for a long time, China has been paying attention to the development and application of box type substation, and has been actively preparing and technical reserves in this regard. Although so far, box type substation has no actual operation performance in the field of urban rail transit in China, the technology of box type substation has developed mature and has been widely used in the field of rail transit in other countries and regions. Not long ago, Shanghai Metro Corporation took the lead in the field of rail transit in China, that is, the Shanghai Metro Xinmin line rail transit project, and ordered a box type substation of traction substation produced by American power company, which is expected to be put into use by the end of this year; Later, in the Gonghexin Road rail transit project, four box type substations produced by American power company were ordered and are expected to be put into use by the end of next year

the five traction substations in Tianjin Jinbin rapid rail transit project are also prepared to adopt the box type substation, which is expected to be put into use at the end of July next year. In Tianjin Metro Line 1 project, some traction substations are planned to adopt box type substation, which is expected to be put into use at the end of 2005

III. characteristics of box type substation

as we all know, the line planning of urban rail transit and the stations distributed along the line are basically within the range of 18000 tons per year built in the first phase of the urban area. As an urban infrastructure, each station along the line generally has landscape and modeling requirements. Generally, the construction scale and land demand of the traditional traction step-down hybrid substation are relatively large. If the traction substation (the area of the traditional traction substation is about 400m2, and the area of the box type substation is about 100m2) is built together with the station, it is difficult to realize the landscape modeling of these stations in the architectural design; In addition, in order to meet the larger land requirements of traditional traction substations, the corresponding demolition workload is increased, and the demolition costs and land acquisition costs are increased, which also leads to the difficulty of the project. Therefore, the traction substation in the traction step-down hybrid substation can be moved out of the station, and the box type substation can be used for separate construction, while only the step-down part (usually the area of the step-down part is about 100m2) can be built together with the station, which can better solve this problem

in the planning of urban rail transit projects, considering the passenger flow in the early and short term of operation, some stations are designed as reserved stations in the early and short term, and these stations are usually built after several years in the long term; The traction substation located in the reserved station needs to be built and put into operation first because of its operation. Therefore, when the station is built several years later, with the development of urban economy, the scale, specific location or scheme of station construction in the later stage is likely to change. In this way, if the box type substation is used for the traction substation built and put into operation in the early stage, it can be easily removed, which not only reduces the removal workload, but also greatly reduces the removal period, Moreover, the power outage time can be greatly shortened without affecting the running of the whole line; And it can be well coordinated with the later stations

in addition, box type substation is especially suitable for urban rail transit projects with very tight construction period. If the traditional traction substation is adopted, the construction and installation, the commissioning cycle between equipment is relatively long, and the on-site cooperation workload is large; The box type substation is assembled and debugged in the factory, and the workload of on-site cooperation is relatively small

in practical engineering applications, the box type substation is to assemble the main equipment in the traditional traction substation in a factory prefabricated steel structure container. The box type substation used in the project should include the following main equipment:

medium voltage AC switchgear

traction rectifier

DC switchgear, negative cabinet, drainage cabinet, rail potential limiting device

control signal panel AC/DC power panel

distribution transformer or power distribution transformer, etc.

in addition, ordinary lighting devices, emergency lights, power sockets, ventilation systems, anti condensation devices, interconnection cable trunking between equipment, etc. can also be installed in the container. In addition, according to the actual needs, you can also choose to install air conditioners, disaster prevention alarm devices, anti illegal entry devices, and so on. The above equipment is installed and debugged in the factory, and then transported by the factory to the substation installation site for direct installation

in short, compared with the traditional substation, the box substation has the following advantages:

reduce the size of the traditional substation to the minimum, compact volume and layout, small floor area, and save investment; Compared with the conventional substation, the floor area of the box type substation with the same capacity is usually only 1/4~5 of that of the conventional substation. At present, the foam granulator industry should pay attention to this environmental protection problem, which greatly reduces the construction volume and reduces the construction cost

it is completely pre manufactured by the factory, installed and debugged intensively, and has little impact on the site; Improve the degree of industrialization in the project and reduce the workload of on-site installation; Minimize the impact of on-site installation and commissioning on equipment quality

when transported to the installation site, it only needs to be installed and connected with external equipment, and the quantity of on-site installation is minimized

the selection method of aluminum profile fixture for the demolition party is convenient

the interface with the outside is less and simple

suitable for use in urban environment, easy to coordinate with other surrounding buildings

less maintenance workload

not affected by external climatic and environmental conditions

can effectively shorten the on-site construction period

IV. contents of interface coordination between box type substation and other disciplines

box type substation usually carries out unified installation, connection, wiring and commissioning of each single equipment in the box in advance in the factory, and then transports it to the installation site for construction installation and connection with external cables. It usually has interface coordination with the following disciplines, but the contents of interface coordination are relatively few And simple:

1 Soil and housing construction specialty

because the box type substation is installed outdoors, there is no need for special equipment room, only the soil and housing construction specialty needs to provide concrete foundation for installation and cable trench for laying cables outside the box, which greatly simplifies the coordination work of the two specialties and shortens the coordination cycle

2. Power supply specialty

medium voltage ring power supply cable:

it is necessary to connect the external AC power cable from other substations with the corresponding reserved cable position in the box type substation at the installation site

lead wire cable and bilateral jump cable:

it is necessary to connect the external lead wire and bilateral jump cable from other substations with the corresponding reserved cable position in the box type substation at the installation site

3. Contact professional

DC 1500V positive feeder circuit:

it is necessary to connect the cable of the external connection contact electric disconnector with the cable position reserved in the box type substation at the installation site

traction return circuit:

it is necessary to connect the external cable contacting the return box with the cable position reserved in the box type substation at the installation site

4. The power, lighting, wiring, power distribution, switches, power sockets, air conditioning equipment, etc. inside the box type substation are all centrally assembled and debugged in the factory. After arriving at the site, it is usually only necessary to connect 400V power supply

5. Disaster prevention and alarm specialty

the disaster prevention and alarm equipment inside the box type substation, such as smoke and temperature, are all assembled and debugged in the factory

6. Connect the external cable connecting the stray current collection with the cable position reserved in the box type substation at the installation site with the stray current protection specialty

v. overall structure of box type substation box

box type substation should be designed to safely carry out normal use, inspection and maintenance

the substation shall be simple in structure, reliable in performance, safe in operation, practical and beautiful, convenient for test and maintenance, and its appearance shall be coordinated with the environment

1. General requirements for plane layout of power supply equipment in the box

each rectifier transformer shall have a separate compartment. In the plane layout design, the space for operation inspection and maintenance of the equipment in the box shall be considered under the condition of meeting the relevant GB and IEC standards. Corresponding lighting facilities (including normal lighting, emergency lighting and maintenance lighting), ventilation facilities, fire-fighting facilities, communication and network interface facilities and environmental requirements to ensure the normal operation of electrical equipment shall be set in the box

2. Box structure and configuration of box type substation

the structural design of the box shall meet the requirements of rain, snow, leakage, corrosion, dust, small animal entry, theft prevention, corrosion resistance, etc. The box is equipped with an operation corridor (staff operate in the box). According to the site conditions, the box type substation can be a