Intelligent high-speed direct-current remote power supply system

Abstract

The invention discloses an intelligent high-speed direct-current long-distance power supply system which comprises a local side machine which is installed in a power supply machine room of an expressway toll station or a service area, a power source is introduced from an alternating-current 380V switch cabinet of a substation and boosted to DC750V through isolation rectification, the local side machine adopts an efficient multi-pulse-wave rectification technology, stability and efficiency of power source output are ensured, and the local side machine is installed in a power supply room of the expressway toll station or the service area. Meanwhile, a protection device is arranged to ensure system safety; the direct-current power supply cable is connected with the local side machine and the far-end machine, adopts a high-voltage direct-current transmission mode, and is laid in the same pipe or the same ditch with the optical cable in the highway communication pipeline; a far-end machine and a hoop are installed on the intelligent rod, a power supply is introduced from a direct-current cable in a T connection mode through a puncture wire clamp, and a built-in inverter inverts DC750V into AC220V single-phase power; the method has the advantages that the direct current power supply technology is stable in voltage and current and is not affected by power grid fluctuation, and it is ensured that the power utilization environment of equipment is stable; compared with 10KV power supply, the direct-current power supply system is short in construction period, low in cable cost and simple to operate and maintain.

Description

Technical Field

[0001] The present invention belongs to the technical field of direct current remote power supply, and in particular relates to an intelligent high-speed direct current remote power supply system. Background Art

[0002] The development of 5G Internet of Things makes vehicle-road collaboration and unmanned driving possible. Currently, provinces are only conducting pilot projects on smart highways, but as various technologies continue to mature and improve, smart highways will surely usher in huge market opportunities for explosive development.

[0003] The development of smart highways will evenly distribute 5G base stations, vehicle-road cooperative unmanned driving signal equipment, video cloud networking and many other sensing devices along the highways. These devices require safe and stable power supply. Due to the unstable power consumption of photovoltaic power, the AC 380V power supply distance is too short, and the construction period of 10KV power supply is long, and the construction cost and operation and maintenance cost are too high. Therefore, low-cost, stable long-distance power supply is a "pain point" problem that restricts the future development of smart highways. Summary of the invention

[0004] The purpose of the present invention is to provide a smart high-speed DC long-distance power supply system to solve the shortcomings of existing power supply solutions in terms of stability, cost, construction cycle and operation and maintenance difficulty, and to meet the needs of various sensing devices on smart highways for safe and stable power supply.

[0005] To achieve the above object, the present invention provides the following technical solutions: an intelligent high-speed DC long-distance power supply system, including a local terminal, which is installed in a power supply room at a highway toll station or service area, and introduces power from an AC 380V switch cabinet of a substation, and is isolated, rectified and boosted to DC750V. The local terminal adopts high-efficiency multi-pulse rectification technology to ensure the stability and efficiency of power output, and is equipped with a protection device to ensure system safety;

[0006] The DC power supply cable connects the local terminal and the remote terminal, adopts high-voltage DC transmission mode, and is laid in the same pipe or trench as the optical cable in the highway communication pipeline;

[0007] The remote unit is installed on the smart pole with a clamp. The power supply is introduced from the DC cable through a T-connection through a puncture wire clamp. The built-in inverter converts DC750V into AC220V single-phase power to supply the load control box and subsequent equipment.

[0008] Visually view the terminal, alarm unit, and handheld terminal to achieve remote system monitoring, fault alarm, and information push; the alarm unit is used to monitor the system, and when a fault occurs, the maintenance information is transmitted to the staff's handheld terminal for timely maintenance.

[0009] As a preferred technical solution of the present invention, it also includes a positioning unit, through which the fault position is located when a fault occurs.

[0010] As a preferred technical solution of the present invention, the method used to locate the fault position is one of traveling wave fault location, single-terminal fault analysis method and two-terminal fault analysis method.

[0011] As a preferred technical solution of the present invention, the local terminal adopts an 18-pulse multi-winding transformer design to complete the rectification of AC380V into DC750V power supply, thereby realizing DC high-voltage remote supply.

[0012] As a preferred technical solution of the present invention, the protection device includes an isolation rectifier device, a boost module, overvoltage protection, undervoltage protection, short circuit protection, overload protection, leakage protection, and temperature protection.

[0013] As a preferred technical solution of the present invention, the visual viewing terminal realizes system remote monitoring including the following contents:

[0014] Data collection: Collect various electrical parameters and equipment status information on site, and send the data to the visual viewing terminal through the preset communication protocol;

[0015] Data transmission: Use efficient and stable communication protocols to ensure the accuracy and real-time nature of data during transmission; at the same time, use encryption technology to protect data security and prevent data from being illegally obtained or tampered with;

[0016] Data processing: After the visual viewing terminal receives the data, it first processes and analyzes the data for subsequent visual display and decision support;

[0017] Visual display: The processed data is presented on the screen through charts, tables, maps and other visualization methods.

[0018] As a preferred technical solution of the present invention, data processing and analysis include data cleaning, conversion, and compression.

[0019] As a preferred technical solution of the present invention, the communication protocols include MQTT and HTTP.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The DC power supply technology has stable voltage and current, and is not affected by grid fluctuations, ensuring a stable power environment for the equipment;

[0022] Compared with 10KV power supply, DC power supply system has short construction period, low cable cost and simple operation and maintenance. DC power supply is not affected by line inductance and capacitance and has long transmission distance, which can meet the needs of smart highway long-distance power supply.

[0023] Adopting DC suspension transmission technology, single-pole leakage without electric shock risk; multi-pulse power supply has long life and strong instantaneous overload capacity;

[0024] Existing communication pipelines on expressways can be used to lay cables, reducing construction difficulty and cost;

[0025] The system can adapt to outdoor high and low temperature environments to ensure stable operation under various climatic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the principle diagram of the central office terminal of the present invention;

[0027] Figure 2 It is the principle diagram of the remote machine of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] See also Figure 1 and Figure 2 , which is the first embodiment of the present invention, and provides a smart high-speed DC long-distance power supply system, including a local terminal, which is installed in a power supply room at a highway toll station or service area, and introduces power from an AC 380V switch cabinet of a substation, and is isolated, rectified and boosted to DC750V. The local terminal adopts high-efficiency multi-pulse rectification technology to ensure the stability and efficiency of power output, and is equipped with a protection device to ensure system safety;

[0031] The DC power supply cable connects the local terminal and the remote terminal. It adopts high-voltage DC transmission mode and has the advantages of stable voltage and current, no electromagnetic interference, low power loss, and long transmission distance. The cable has a small diameter and good electromagnetic compatibility. It is easy to lay in the same pipe or trench with the optical cable in the highway communication pipeline, reducing the construction difficulty and cost.

[0032] The remote unit, with a clamp installed on the smart pole, introduces power from the DC cable through a T-connection through a puncture wire clamp. The built-in inverter converts DC750V into AC220V single-phase power to supply the load control box and subsequent equipment. The design of the remote unit takes into account safety measures such as leakage prevention and electric shock prevention to ensure the safety and reliability of the system. The remote unit (inverter) adopts SPWM inverter technology to complete the conversion of DC750V to AC220V on site to supply power to the smart pole load.

[0033] Visually view the terminal, alarm unit, and handheld terminal to achieve remote system monitoring, fault alarm, and information push; the alarm unit is used to monitor the system, and when a fault occurs, the maintenance information is transmitted to the staff's handheld terminal for timely maintenance.

[0034] Example 2

[0035] See also Figure 1 and Figure 2 , which is the second embodiment of the present invention, and provides a smart high-speed DC long-distance power supply system, including a local terminal, which is installed in a power supply room at a highway toll station or service area, and introduces power from an AC 380V switch cabinet of a substation, and is isolated, rectified and boosted to DC750V. The local terminal adopts high-efficiency multi-pulse rectification technology to ensure the stability and efficiency of power output, and is equipped with a protection device to ensure system safety;

[0036] The DC power supply cable connects the local terminal and the remote terminal. It adopts high-voltage DC transmission mode and has the advantages of stable voltage and current, no electromagnetic interference, low power loss, and long transmission distance. The cable has a small diameter and good electromagnetic compatibility. It is easy to lay in the same pipe or trench with the optical cable in the highway communication pipeline, reducing the construction difficulty and cost.

[0037] The remote unit, with a clamp installed on the smart pole, introduces power from the DC cable through a T-connection through a puncture wire clamp. The built-in inverter converts DC750V into AC220V single-phase power to supply the load control box and subsequent equipment. The design of the remote unit takes into account safety measures such as leakage prevention and electric shock prevention to ensure the safety and reliability of the system. The remote unit (inverter) adopts SPWM inverter technology to complete the conversion of DC750V to AC220V on site to supply power to the smart pole load.

[0038] Visually view the terminal, alarm unit, and handheld terminal to achieve remote system monitoring, fault alarm, and information push; the alarm unit is used to monitor the system, and when a fault occurs, the maintenance information is transmitted to the staff's handheld terminal for timely maintenance.

[0039] In this embodiment, preferably, a positioning unit is further included, and the positioning unit is used to locate the fault position when a fault occurs; the method used to locate the fault position is one of traveling wave fault positioning, single-end fault analysis method, and two-end fault analysis method; the traveling wave fault positioning technology is a positioning method based on the propagation characteristics of transient traveling waves. When a line fault occurs, transient traveling waves are generated. These traveling waves propagate between the bus and the fault point at a very stable speed. By measuring the propagation time of the transient traveling waves and the length or wave speed of the line, the distance from the fault point to the measurement point can be calculated, thereby locating the fault position. The traveling wave method distance measurement has good reliability and high measurement accuracy;

[0040] Single-ended fault analysis is another common fault location method. It mainly relies on the electrical quantity information at one end of the line to perform fault analysis. For example, the current, voltage and other signals generated during a fault can be used in combination with the distributed parameter model of the line to determine the fault location through mathematical calculation or algorithm analysis. The single-ended fault analysis method has the advantages of simple implementation and low cost.

[0041] The two-terminal fault analysis method uses the electrical quantity information at both ends of the line to locate the fault. Compared with the single-terminal method, the two-terminal method can more comprehensively reflect the fault characteristics of the line, so it usually has higher positioning accuracy. Its basic principle is to calculate the fault location based on the time difference between the fault traveling wave reaching the two ends of the line, combined with the length and wave speed of the line. In order to achieve synchronous measurement and analysis of the two-terminal quantities, a dedicated time synchronization unit is usually required, such as the GPS global positioning system.

[0042] In this embodiment, preferably, the local terminal adopts an 18-pulse multi-winding transformer design to complete the rectification of AC380V into DC750V power supply, thereby realizing DC high-voltage remote supply.

[0043] In this embodiment, preferably, the protection device includes an isolation rectifier device, a boost module, overvoltage protection, undervoltage protection, short circuit protection, overload protection, leakage protection, and temperature protection.

[0044] In this embodiment, preferably, the visual viewing terminal realizes the remote monitoring of the system including the following contents:

[0045] Data collection: Collect various electrical parameters and equipment status information on site, and send the data to the visual viewing terminal through preset communication protocols such as MQTT and HTTP;

[0046] Data transmission: Use efficient and stable communication protocols to ensure the accuracy and real-time nature of data during transmission; at the same time, use encryption technology to protect data security and prevent data from being illegally obtained or tampered with;

[0047] Data processing: After the visual viewing terminal receives the data, it first processes and analyzes the data, including data cleaning, conversion, and compression steps, so as to facilitate subsequent visual display and decision support;

[0048] Visual display: The processed data is presented on the screen through charts, tables, maps and other visualization methods.

[0049] Engineering applicability analysis:

[0050] In order to verify the engineering applicability of the multi-pulse DC remote power supply system technical solution, a test was conducted on the Renshou section of the Chengyi Expressway (Chengdu to Yibin), the first digital highway in Sichuan Province. According to the on-site line conditions, the Outang toll station of the test section was used as the power supply starting point, and the DC power supply transformation was carried out to the load in the Longma direction of the test section, and the single-ended power supply from K85+157 to K75+541 was about 10km. A 380V local cabinet will be set up in the toll station substation to rectify the incoming AC power and convert it into a DC 750V power supply for transmission; the local cabinet input is a three-phase four-wire system, with a rated input of 230V single-phase voltage and a rated output voltage of 750V.

[0051] The inverter integrated cabinet (remote unit) is installed on the existing smart pole in the form of a clamp. At each smart pole load location, the DC 750V is converted into AC 220V single-phase electricity through the inverter and connected to the AC 220V main switch in the smart pole;

[0052] When conducting the central office test: the central office has an output voltage of 755.8V under the load of 13 inverter cabinets, which meets the requirement of 750V±20%. At the same time, under 13 inverters, the efficiency is greater than 95%, which meets the design requirements.

[0053] The inverter test results are as follows: the output voltage of 13 inverters is within 220V±5%, which meets the design requirements;

[0054] When 13 inverters are in operation, the input DC voltage at the cable end of the farthest inverter No. 13 is 633V, and the voltage drop is (753-633) / 753*100%=15.9%, which is within 20% and meets the design requirements.

[0055] The normal operating voltage of the inverter adopts a wide range of 400V to 800V DC input, and the terminal voltage is 633V, which meets the normal operating voltage requirements of the inverter. After testing, all inverters are working normally and the output voltage is stable, as shown in the measured data and waveform drawings, which meet the design requirements. System simulation test:

[0056] Combined with the actual situation on site, the DC power supply system is modeled and simulated according to the actual measured load size and cable laying distance to verify the actual measurement;

[0057] The actual output current of the central office is 11.07A, and the simulation result shows that the current of the central office is 10.7A, with an error of 3.3%, which meets the error range of 5%.

[0058] The actual measured value of the terminal voltage is 633V, and the simulation result shows that the terminal voltage is 615V, with an error of 2.8%, which meets the error range of 5%.

[0059] System compatibility analysis:

[0060] Compatibility of new energy access and energy management: Due to the characteristics of new energy power generation as direct current, a new energy microgrid can be reserved in the DC 750V transmission network to access the network to power the equipment, achieving the low-carbon and environmentally friendly concept of "clean energy, green symbiosis". At the same time, by installing intelligent measurement and control and energy management systems at new energy access points, real-time new energy management and statistics can be achieved, thereby optimizing the power supply network and saving power supply costs;

[0061] System support power supply compatibility: The system adopts DC power supply, and the inverter adopts wide range voltage input. When a local terminal fails and is disconnected, power supply 1 and power supply 3 can support power supply to power supply 2 under the condition of meeting the voltage drop and load power, further improving the reliability and stability of the system;

[0062] According to the type of equipment in the outdoor field, multiple power output solutions can be compatible, that is, DC750V is installed at the outdoor smart pole to step down to DC (48V / 24V / 12V / 5V) power supply, which can directly meet the voltage requirements of various electrical equipment. The electrical equipment saves the adapter (driving power supply), has higher stability, longer life, and higher power conversion efficiency; at the same time, the integrated cabinet integrates the intelligent power management system and UPS power supply. When an abnormality occurs on the power supply side, the bus voltage is maintained at DC750V to ensure normal power supply at the back end, minimize the impact range after a fault occurs, and meet the needs of stable and reliable power supply for different power levels of equipment in the outdoor field.

[0063] Although the embodiments of the present invention have been shown and described, as detailed above, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smart high-speed DC long-distance power supply system, Features: It includes the local terminal, which is installed in the power supply room of the highway toll station or service area. The power is introduced from the AC 380V switch cabinet of the substation and is boosted to DC750V through isolation rectification. The local terminal adopts high-efficiency multi-pulse rectification technology to ensure the stability and efficiency of the power output, and is equipped with protection devices to ensure system safety. The DC power supply cable connects the local terminal and the remote terminal, adopts high-voltage DC transmission mode, and is laid in the same pipe or trench as the optical cable in the highway communication pipeline; The remote unit is installed on the smart pole with a clamp. The power supply is introduced from the DC cable through a T-connection through a puncture wire clamp. The built-in inverter converts DC750V into AC220V single-phase power to supply the load control box and subsequent equipment. Visually view the terminal, alarm unit, and handheld terminal to achieve remote system monitoring, fault alarm, and information push; the alarm unit is used to monitor the system, and when a fault occurs, the maintenance information is transmitted to the staff's handheld terminal for timely maintenance.

2. According to claim 1, a smart high-speed DC long-distance power supply system, Features: It also includes a positioning unit, through which the fault position is located when a fault occurs.

3. According to claim 2, a smart high-speed DC long-distance power supply system, Features: The method used to locate the fault position is one of the traveling wave fault location, single-ended fault analysis method, and two-ended fault analysis method.

4. According to claim 1, a smart high-speed DC long-distance power supply system, Features: The local terminal adopts an 18-pulse multi-winding transformer design to complete the rectification of AC380V into DC750V power supply, realizing DC high-voltage remote supply.

5. According to claim 1, a smart high-speed DC long-distance power supply system, Features: The protection device includes an isolation rectifier device, a boost module, overvoltage protection, undervoltage protection, short circuit protection, overload protection, leakage protection, and temperature protection.

6. According to claim 1, a smart high-speed DC long-distance power supply system, Features: The visual viewing terminal implements the system remote monitoring including the following contents: Data collection: collecting various electrical parameters and equipment status information on site, and sending the data to the visual viewing terminal through a preset communication protocol; Data transmission: Use efficient and stable communication protocols to ensure the accuracy and real-time nature of data during transmission; at the same time, use encryption technology to protect data security and prevent data from being illegally obtained or tampered with; Data processing: After the visual viewing terminal receives the data, it first processes and analyzes the data for subsequent visual display and decision support; Visual display: The processed data is presented on the screen through charts, tables, maps and other visualization methods.

7. The intelligent high-speed DC long-distance power supply system according to claim 6, Features: Data processing and analysis include data cleaning, conversion, and compression.

8. According to claim 6, a smart high-speed DC long-distance power supply system, Features: Communication protocols include MQTT and HTTP.

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