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Power Supply Design of Urban Rail Transit


Abstract: Entering the twenty-first century, with the rapid development of national economy and the acceleration of urbanization process, urban rail transit also entered the period of great development. Rail distribution as an important component of mass transit, plays a very important role. Keywords: power; power monitoring; fixed according urban mass transit public transport system as an important part of the present subway, light rail, trams and trains and other types of suspension, known as It has energy, and land, all-weather, large volume, and security features, is a green transportation system, in line with the principles of sustainable development, especially suitable for large and medium cities. An external power supply and the main substation present, the power supply rail transit are two types: centralized and decentralized power supply power supply. When a decentralized power supply, each traction substation, step-down substation cited respectively by two nearby existing power grid independent 35kV or 10kV power supply rail without the main substation. Centralized power supply mode, set the main substation, the power from the grid into fewer, high-voltage power supply access, generally does not involve transformation of urban and rural power substation, from urban and rural areas to urban rail transport network cited the main substation a small number of the cable path, power reliability, power supply to facilitate implementation of the project, so that rail traffic into the power supply system since, due to the high voltage by other users affected by the failure of urban and rural power grid less convenient operation and management, resulting in high-order harmonic wave into the power grid was relatively small. Second, the composition of medium voltage power supply network and the voltage level different forms according to wiring, voltage network in the form of two basic components: one is to a full range of stations divided into several power substations partitions, each partition by the nearest main substation (or power opening and closing) of the station from the main substation (or power opening and closing) the introduction of two power stations within the zone of the substation connected to form ring ; the other is adjacent to two of the substation for a group of stations, two stations along the access from the main power substation at higher levels, are another way from the adjacent power station. Different functions according to the network for the medium voltage substation power network can be described as traction network; for the step-down substation power network can be described as dynamic lighting network. Third, the choice of traction mode China's current urban rail transit traction by way of divided into two streams, one is exposed by the current track, the other is the overhead catenary by the stream by contact rails flow method is divided into DC750V and DC1500V two cases. Contact with the two rail system landscape compared to good effect, easy maintenance and management system, but the investment is large, and to adapt to a lower speed, in case of emergency, there are some personal safety hazards. Overhead catenary system technology is mature, small investment to meet higher speed, security and high reliability. IV substation distribution scheme, Traction Substation is the number, location and capacity, to be based on the information plane and profile lines, traffic organization program, vehicle marshalling and load conditions, calculated by traction power supply identified between the use of bilateral power substation to improve power quality and energy conservation. V. electric power monitoring system monitoring system is set in the master control center monitoring system, set in a variety of integrated substation automation and contact between the two subsystems and power plant complex transmission channel said terminal form, the system uses computer-based monitoring device, the structure of the form 1: N-point structure. (1) Master Station - located in the master control center monitoring system. (2) charged Station - located in the main substation, traction step-down mixing, traction substation, such as the integrated step-down substation automation system. (3) transmission channel - using communications professional to provide data transmission channel. (4) power plant repeater terminal - by scheduling system across the board to forward the information to monitor the operation of power system equipment. The line is divided into power control system, the main substation of the line, step-down hybrid traction substations, step-down transformer substation, traction power supply facilities and other major operating state and the relevant parameters of stray current real-time monitoring, control, data acquisition and processing, the control center focused on the automation of power supply equipment to achieve scheduling management to ensure that the traction power supply system and the line of safe and reliable electric power transformation and distribution system and economic operation. VI catenary system is the catenary system to provide power to the EMU and no backup power supply equipment, catenary principles of research and design should meet the speed and improve the technical and economic performance, to achieve safe and reliable operation requirements. Seven, dynamic lighting system 1, step-down substation can station power load distribution, concentrated in the side of the load step-down transformer substation, together with the traction substation mixed substation construction. Depot, the control center according to the distribution of electricity load, set the indoor power supply step-down substation for the electricity load. 2, dynamic lighting (1) load classification. 1) a load. Communications, signals, emergency lighting, fire fighting equipment, accidents fans, fire alarm equipment, computer system, an important drainage pump, automatic fare collection equipment, evacuation and vertical lifts with escalators, automatic alarm system equipment. 2) The second load. Public area site concourse lighting, room lighting subsidiary, ordinary fans, the general supply and drainage pumps, escalators, elevators, sewage pumps. 3) The third load. Air conditioners, electric equipment, advertising lighting, cleaning and maintenance of machinery, boilers, equipment. A load of double lines should be dual power supply, power supply systems in some part of the failure should also ensure their supply. Usually by the second load any of a substation and secondary load bus power supply. Three load power supply usually by the way, when the only way the power should be promptly removed from the grid. (2) power distribution and lighting control. 1) power distribution and control equipment. Power distribution equipment, mainly by radio-style, some smaller capacity,[link widoczny dla zalogowanych], the relative concentration of the second and third load can be trunk-style power supply. Important to a load such as signal, communications, integrated station control room equipment from the electricity substation, automatic fare collection, fire pump, etc. directly from the dual power supply step-down to the device end. Power equipment control mode: local control by fire-fighting equipment, station control room, control center remote control three-level control; other power equipment used according to the specific needs of local control process, the station control room control, automatic control other three ways. 2) lighting distribution and control. Station lighting according to the functions are divided into general lighting, emergency lighting (and duty lighting), advertising lighting, marking lighting, equipment management space lighting, security lighting, power distribution methods of their use of radial and trunk-style combination. Emergency lighting and evacuation instructions light induced by EPS centralized power supply, power supply capacity to meet the needs of 90 minutes; stations generally to fluorescent-based lighting, lighting in public places should be chosen to match architectural forms; depot, parking Field and other outdoor areas with lights and lamps for light bending tower lighting. Lighting Control: Lighting subsidiary housing approach with local control; public areas for general lighting control system with intelligent lighting control; emergency lighting controlled by the disaster alarm. (3) integrated grounding system. The integrated ground network stations are set to meet the traction power supply equipment, station electrical and mechanical equipment, communication signals and other information equipment, and other ground water supply and drainage requirements, grounding resistance under normal circumstances not more than 1Ω. Integrated grounding for ground stations to make full use of natural building base, grounding, if it can not meet the design requirements should be laid artificial grounding. Papers order to ensure reliable power supply system, power supply must have a reasonable solution, so performance and low cost, easy to operate, affordable building standards, electrical and mechanical equipment using domestic technology, and most mature products, effective control of the investment, economic benefit is remarkable.