How to ensure reliable power supply of Expressway

Encore Hua Nan

Abstract : Nowadays, with the rapid economic development , Rapid development of logistics 、 The rapid growth of people's car ownership leads to the continuous increase of highway mileage , It makes the management of Expressway face greater pressure . The power supply and distribution system of the expressway is used for monitoring the facilities along the expressway 、 signal communication 、 Charging system equipment 、 Maintenance service facilities and road lighting services , The purpose is to ensure the safety of its electricity 、 Reasonable and reliable , Ensure highway safety 、 unobstructed 、 economic 、 Fast and other comprehensive benefits . This paper briefly discusses the concept of Expressway power supply and distribution system , The highway tunnel is analyzed 、 service area 、 Power supply demand of toll station substation , According to the characteristics of expressway, the corresponding solutions are put forward .

keyword ： Expressway ; Supply and distribution ; reliable ;

1. Industry background

According to the statistics of the Ministry of transport ,2015-2019 year , China's investment in highway construction has continued to rise ,2019 year , The national expressway construction has completed the investment 11504 One hundred million yuan , According to comparable caliber , Year-on-year growth 14.5%.2020 In, the national expressway was completed 13479 One hundred million yuan , growth 17.2%.2020 year , Highway mileage in China 16.44 Thousands of kilometers , increase 1.14 Thousands of kilometers ; Highway lane mileage 72.31 Thousands of kilometers , increase 5.36 Thousands of kilometers . National highway mileage 11.30 Thousands of kilometers , increase 0.44 Thousands of kilometers .

The development of Expressway in China is very rapid . A national expressway network has been formed , While making outstanding contributions to national economic development , It is also safe for the power supply and distribution system of the expressway 、 Rationality and reliability pose a severe test .

2. High speed power supply and distribution analysis

The expressway power supply and distribution system adopts centralized or relatively centralized power supply. The power used is led from the power plant or the high-voltage power grid in the nearby area 10kW or 35kW High voltage transmission to the substation of the expressway , Low voltage transformer is used to generate 220V or 380V Supply voltage of , Then it will be sent to relevant electrical equipment by low-voltage distribution panel and transmission line . In case of power failure or failure of normal power supply , The power is generated and supplied by the self provided diesel power generation equipment .

In the actual operation of Expressway Electromechanical Engineering , The load of various electrical equipment varies , Overload will cause waste of investment and equipment , Too little load will also lead to equipment damage . Therefore, it is necessary to calculate the load reasonably in the design stage of power supply system , To avoid waste of resources and ensure the safety of system operation .

The important load of tunnel substation is generally emergency lighting facilities 、 Ventilation and lighting control facilities 、 Emergency call facilities and some fire-fighting equipment . The tunnels are all located in remote areas , More rural power is used , As the rural electricity itself is unstable , Often face the risk of power failure , It is generally used EPS emergency supply . If the load has equipment with high voltage requirements, it can be controlled by UPS Power supply .

 

Power supply and distribution system of tunnel substation

The important load of the toll station substation is generally the communication system 、 Toll system 、 Monitoring system, etc . Permanent UPS For the operating mechanism 、 Monitoring equipment 、 Measurement and control unit and ATS Power supply .

 

Power supply and distribution system of toll station substation

The important load of the substation in the service area is generally monitored in the field 、 communication system 、 Life water pump 、 Fire hydrant pump 、 Lighting of complex building 、 Site lighting, etc .

 

Power supply and distribution system of substation in service area

3. Reliable power supply scheme

    1） Whole section monitoring

There are dozens of substations along the road 、 Section box type substation 、 Tunnel substation 、 Service area substation 、 The toll station substation is drawn on a sheet K Inside the line diagram , Click each station to jump to the relevant electrogram screen , So that the power distribution system of the whole expressway can be mastered in one diagram .

 

2）10kV System monitoring

Yes  10kV Incoming and outgoing lines 、 Bus section and other circuits shall be used for relay protection and operation measurement and control . Real time display of remote measurement of each circuit 、 Remote signaling quantity 、 Alarm signal 、 Temperature value of electrical nodes in the cabinet, etc .

 

3）0.4kV System monitoring

0.4KV Incoming unit of distribution cabinet and generator incoming cabinet 、 Contact switch cabinet, etc , Monitor its electrical parameters , Monitor switch position signal 、 Circuit opening and closing status 、 Fault tripping signal, etc ; And the incoming switch （ Low voltage circuit breaker includes automatic mechanism such as electric operation ） Conduct remote opening and closing control . And monitoring UPS、EPS Outgoing line voltage 、 Battery voltage 、 electric current 、 Power and other real-time quantities .

 

4） Transformer monitoring

Monitor transformer current 、 voltage 、 Meritorious / Reactive power 、 power factor 、 Load rate 、 Three phase winding temperature 、 Three phase unbalance and other data . Set microcomputer transformer protection and measurement device , It can realize on-site 、 Telecontrol protection 、 Measurement and control function , The electric power monitors the temperature signal of the dry transformer through the embedded temperature sensor inside the dry transformer and the corresponding intelligent temperature controller 、 Overtemperature alarm 、 Monitor the operation status of transformer such as the working status of transformer fan .

 

5） Power quality monitoring and control

harmonic / Interharmonic 、 Harmonic distortion rate 、 Voltage deviation 、 Steady state monitoring of voltage and current such as voltage fluctuation and flicker , Temporary rise 、 Sag 、 short-term 、 Tolerance analysis voltage transient monitoring 、 Voltage transient monitoring . The controller of intelligent reactive power compensation device and intelligent active filter device is connected to intelligent communication management machine , Display its operation status through the power monitoring host , Harmonic control .

 

 

 

6） Event alarm handling

The system can control the distribution circuit breaker 、 Isolating switch 、 Grounding knife switch 、 Remote signaling displacement such as closing action , Protective action 、 Give an alarm in case of accident trip and other events , And conduct quotation analysis . Divide the alarm into four levels ： early warning 、 commonly 、 important 、 Emergency alarm ; Adopt element alarm 、 Pop up the event alarm window 、 Voice alarm 、 SMS alerts 、 Phone alert 、 Audible and visual alarm, etc .

 

 

4． summary

To make a long story short , The safe operation of expressway can not be separated from the support of perfect power system , Configuring safe and reliable power supply is the premise to ensure the stable operation of expressway system . Real time monitoring of various power supplies , Ensure the continuous supply of stable power supply , And timely feed back the operation of the whole high-speed line to facilitate timely troubleshooting .