First, the proposed problem At present, China's thermal power unit on the water wells to monitor and control the conditions of wells mainly to manually operate or hydraulic control room control. Both of these methods use conventional meters and set up a separate pump over-current protection device. The level of automation is very low. Manual operation is performed on site. Due to the disperse of wells, a lot of manpower is wasted. The control in the hydraulic control room will also be due to well dispersion and water supply. A lot of cable was wasted away from the control room. Based on the above circumstances, in order to realize the goal of reducing people and increasing efficiency and striving for excellence in the Ministry of Electric Power, improving the level of equipment health and equipment automation to achieve safe and economical operation of the units, laying a good foundation for the separation of factories and networks, after thorough investigation, Longkou Power Plant decided to jointly research and develop the wireless remote control and unattended system for the water source of thermal power plants.
Second, the development goals The system is based on intelligent measurement and control of front-end AC sampling, 485 field bus and ultra-short wave wireless communication as the information channel, using PML3720 protocol as the information carrier to achieve water source remote measurement, remote control and automatic integrated protection in place, fully realized The comprehensive automation of the water supply of thermal power plants has reached the goal of being unattended and greatly increasing labor productivity. In addition to the characteristics of a general computer monitoring system, the system should have better flexibility in site requirements, erection of cable stations, etc. The purpose is to minimize the amount of on-site reconstruction work, reduce the input costs of on-site reconstruction, and achieve low investment and high efficiency. . The specific goals are as follows:
1. The system architecture is clear and reasonable, and the 485 fieldbus master-slave communication mode and the wireless broadcast point-to-multipoint communication mode are organically combined.
2. Combining local operation with local operation and remote operation, it ensures the safety of operation, maintenance and overhaul by preventing misoperation logic.
3. Through real-time power factor judgment and analysis, water level alarm can be realized and automatic protection trip can be realized.
4. The entire system must have high reliability. The safety and reliability of the system has an important impact on the personal safety of the operation and maintenance personnel and the service life of the motor. Therefore, it must be able to meet the needs of safe operation and control of the pump well motor. It can complete the over-current and over-voltage protection of the motor, the current and voltage imbalance protection, and the lack of phase protection, to achieve a comprehensive automation of water sources.
5. Multi-point monitoring and control, data acquisition, centralized display processing. A monitoring master station can simultaneously monitor and control multiple remote stations, which is determined by the actual number of wells and booster pumps in the water source. The operator of the power plant network control room can simultaneously monitor the operation conditions of the remote water source, and start and stop the operation of the water source motor according to the actual situation.
6. The system should respond quickly and have good real-time performance. The use of preemptive real-time multi-tasking can collect a variety of analog electrical information of the motor, and can accurately and accurately reflect the running status of each motor through analysis of various analog quantities. The order of processing is determined according to the priority of the task and the importance of the data. Manual control commands have the highest priority. Reading commands such as real-time harmonics has a lower priority. The amount of event data is important and needs to be read in a timely manner. The normal electrical operation parameters are the next and can be read at regular intervals.
7. The system should have a good human-machine interface. The operating personnel can monitor the current operation status of the well motor and each booster pump through the screen. When the parameter exceeds the limit, the alarm information is displayed in a variety of ways. The use of color, sound and other media to remind the operator to pay attention to, and the parameters of the over-limit conditions to record and accumulate, in order to carry out accident analysis, improve the motor's safe operation level play an important role The role. Different operators should be given different operating rights, so that the rights and responsibilities can be clearly defined. Can promote the role of different system maintenance personnel to complete their work, but also to facilitate the work of assessment and accountability. The operator's operation interface should be flexible, convenient, intuitive, simple, and easy to use. It should meet the requirements of skilled operation after short-term training.
8. The system should be easy to upgrade and expand. System hardware selection should fully consider the advanced and reliability to ensure the investment has long-term effectiveness. The system software should be considered for convenient expansion and configurability. The user can easily increase or decrease the system control unit according to actual needs. The system can control the maximum number of intelligent front-ends. The maximum controllable number of 485 fieldbuses is (10 485 busses): 320; the maximum controllable number of wireless modes is: The theoretical value of each serial port is: 9999.
9. The project has low implementation costs, low operating costs and easy maintenance. The implementation of the system should maximize the protection of past investment, reduce new investment, low cost during operation, and facilitate maintenance.
Third, the implementation of the program 1. The overall design of the system combines the main station and the substations. The main station is set up in the pumping station. The main station and the substations in the pump room are connected through the 485 bus. Each well substation communicates with the main station through the radio station, and the main station and the power plant network. The remote station of the control room also communicates through the radio station. The specific structure is as follows:
2. The system hardware is configured on the system hardware configuration. To achieve the organic integration of decentralization and concentration, the specific configuration is as follows:
2.1 The data acquisition equipment adopts the intelligent measurement and control front-end (ACM3720) equipment. Each measurement and control equipment can be installed on the site in a scattered manner. The anti-interference ability is strong, the measurement accuracy is high, and the operation is stable. There are 232 and 485 bus communication interfaces, which can meet the requirements. Rapid data collection requirements.
The main performance of the intelligent monitoring and control front-end (ACM3720) device:
A, input PT, CT for telemetry (more than 300 parameters can be calculated using AC sampling algorithm)
B, 4-way access as remote signaling (resolution of 1ms, each channel can be used for pulse counting)
C, 3 relay outputs can directly control the switch's split/close relays, realize remote control operation, and can realize multiple control and protection functions (over-current, quick-break, over-voltage, over-speed, etc.) Load, etc.)
D. One auxiliary voltage input (Vaux) can measure non-electrical energy such as temperature E, SOE function (100 events can be continuously recorded with a resolution of 1ms)
F, RS485/RS232 communication port measurement accuracy: current, voltage 0.2; power, electrical energy 0.5 The device has a high degree of reliability, strong features, with a good performance and price ratio.
2.2 As the booster pumping station is close to the main station, the monitoring of each pump is directly connected to the monitoring master station using the 485 bus cable, and the communication rate is up to 19200bps, and the data transmission is faster. Because the wells are dispersed and away from the monitoring master station, data communication between the master station and the substations is realized through the ultra-short wave wireless data transmission station. The transmission rate of 1200bps wireless data radio station has been able to meet the needs of monitoring. The digital radio station has stable and reliable time running, simple installation and easy maintenance. The remote station is located tens of kilometers away from the main station and is also a two-way data communication via a wireless data radio station. When the system is implemented, different types of instruments can be connected to the 485 bus to achieve simultaneous monitoring of various devices. The expansion of the system is good. Only by adding the ACM3720 device and the wireless data radio connected to it to the well requiring wireless remote control can the monitoring be realized.
2.3 Both the main station and the remote station adopt a new generation of industrial control computers, which have strong anti-interference ability, stable operation, dust-proof and high-temperature resistance, and are suitable for use in harsh environments to further enhance the reliability of the system.
2.4 The remote station reserved the network interface, which can realize multi-point monitoring after joining the power plant LAN. The remote station communication program design uses the socket UDP protocol to send data by broadcast. The remote station monitoring host is connected to the power plant LAN. Any computer on the LAN installed with client software can be based on Permissions to monitor or operate. Therefore, it will greatly facilitate the technical personnel of the power plant to know the actual conditions of the operation of the water source in a timely manner and facilitate the timely resolution of the problems arising from the treatment.
3. Operating System and Development Software In the system software configuration, the WINNT operating system was selected. WINNT is an operating system with multi-tasking, multi-threading, and high network security. It has stable operation and strong functions. It has a window interface, is easy to operate, and easy to use. It is suitable for use in monitoring systems. WINNT has achieved the C2 security level stipulated by the U.S. government. The WINNT security system borrows object-oriented design ideas. The internal security function not only protects the NT operating system, but also protects the application against attacking bad applications. It also plays a role in virus protection.
3.1 Software design The data collection of communication program adopts the method of interrupting receiving data, which makes the data collection more timely and efficient, and improves the operating efficiency of the entire system.
3.2 Software design The communication program is designed so that the instrument control and data collection are processed according to a prioritized polling method so that the most urgent needs of the user are treated with the highest priority.
3.3 Software design Communication with remote substations in the communication program uses a centralized transmission method, which transfers all required data to remote substations at one time, reducing data traffic and improving communication efficiency.
3.4 The communication program adopts multi-line method and high-performance data collection mechanism.
3.5 Communication software Management software data communication adopts the non-connection-oriented UDP protocol, retains the network interface, can connect with the management information network, and transmit the real-time data directly to the management network to realize real-time data sharing. The advantage of using UDP over connection-oriented TCP is that data can be transmitted without having to establish a connection, and data loss due to unplanned connection interruptions need not be considered.
3.6 Develop a multi-window display management program. Using shared memory technology to achieve rapid refresh of real-time data and each task independently of each other.
3.7 The management program assigns different operation authority to different operators, so that the rights and responsibilities are clearly defined. All operations of the operator are recorded by the system, which promotes the different system maintenance personnel to complete their work and facilitates work assessment.
IV. Introduction to the Development Process 1. July 1998 - August 1998 collected data and system design.
2. September 1998, wireless data transmission equipment selection and field communication test, close distance and long distance. Solve the problem of delay after RTS of digital radio station.
3. The development and debugging of communication programs based on PML protocol from October 1998 to December 1998.
4, January 99-April 99 monitoring software development and debugging.
5. In May 1999-May 1999, the system was installed and debugged on site, and the system was put into operation at the Longkou Power Plant.
Fifth, the key to solve the technology 1, wired and wireless methods organically combined. The design scheme can not only meet the stand-alone application of the main station and the operator station on the same machine but also meet the requirements of multiple operator stations.
2. Improve the wireless modem, increase the RTS signal delay circuit, and solve the problem that data communication between the intelligent measurement and control front-end and the wireless data transmission station cannot be performed normally.
3, to achieve a multi-point monitoring and control. Not only can the water control and control room control all the wells, the power plant network control room operators can also remotely control water wells in water sources that are 30 kilometers away.
4, through real-time power factor judgment analysis, to achieve water level alarm, and can achieve automatic protection trip.
5. Communication program development based on a dedicated communication protocol. The network communication program must ensure the accuracy of the data and ensure the real-time data transmission. Reasonable data structures and good implementation algorithms are the key to the development of communication programs. The compatible use of different types of instruments on the same network is one of the problems that high-performance communication programs need to solve. The communication program can be compatible with the 485 bus master-slave communication mode and wireless broadcast point-to-multipoint mode.
6. Main features of the system Distributed integrated automation system based on industrial fieldbus and wireless broadcast communication.
2. Software and hardware control loops prevent misoperation logic design. Combining local operation with local operation and remote operation, it ensures the safety of operation, maintenance and overhaul by preventing misoperation logic. Achieve multi-point monitoring and control. Not only can the water control and control room control all the wells, the power plant network control room operators can also remotely control water wells in water sources that are 30 kilometers away.
4. The software realizes the well water level alarm and can realize automatic protection tripping.
5. System reliability, high degree of automation.
The measurement and control unit integrates data acquisition, calculation, control, and protection intelligence. System failure does not affect the normal operation of the local measurement and control unit. Failure of a local measurement and control unit will not affect the operation of other measurement and control units.
6. The installation workload of the system is small and the debugging time is short.
Simply connect the pump room collection device to the main station computer via a communication cable. The water well substations only need to add control instruments and wireless data radio stations, and they can use a unified communication protocol to send large amounts of data to computers. This technology greatly reduces the on-site workload and capital investment.
7. The system is easy to use and easy to maintain.
System man-machine interface is good, only need to carry on the brief introduction to the operator, the operator can use skillfully.
8. System configuration flexibility, scalability.
According to the specific needs of the system can be cut, 485 bus way to monitor up to a total of 10 network 320 monitoring and control unit; wireless theoretically, each serial port can control up to 9999 measurement and control unit; there is a dedicated master station and can have one or more Remote station.
This project was completed under the strong support and cooperation of the Longkou Power Plant. It was put into operation in Longkou Power Plant in June of 1999 and has achieved good application results. Since the system adopts an engineering and standardized development model, it adopts a distributed structure combining industrial field bus and wireless broadcast communication. It has a scientific design, complete functions, good versatility and scalability, and is easy to use and maintain. Various types of thermal power plants and environmental monitoring, decentralized monitoring and other fields have very broad prospects for promotion and application. With the further promotion and application of the product, it will play a greater role and generate more social and economic benefits.
Second, the development goals The system is based on intelligent measurement and control of front-end AC sampling, 485 field bus and ultra-short wave wireless communication as the information channel, using PML3720 protocol as the information carrier to achieve water source remote measurement, remote control and automatic integrated protection in place, fully realized The comprehensive automation of the water supply of thermal power plants has reached the goal of being unattended and greatly increasing labor productivity. In addition to the characteristics of a general computer monitoring system, the system should have better flexibility in site requirements, erection of cable stations, etc. The purpose is to minimize the amount of on-site reconstruction work, reduce the input costs of on-site reconstruction, and achieve low investment and high efficiency. . The specific goals are as follows:
1. The system architecture is clear and reasonable, and the 485 fieldbus master-slave communication mode and the wireless broadcast point-to-multipoint communication mode are organically combined.
2. Combining local operation with local operation and remote operation, it ensures the safety of operation, maintenance and overhaul by preventing misoperation logic.
3. Through real-time power factor judgment and analysis, water level alarm can be realized and automatic protection trip can be realized.
4. The entire system must have high reliability. The safety and reliability of the system has an important impact on the personal safety of the operation and maintenance personnel and the service life of the motor. Therefore, it must be able to meet the needs of safe operation and control of the pump well motor. It can complete the over-current and over-voltage protection of the motor, the current and voltage imbalance protection, and the lack of phase protection, to achieve a comprehensive automation of water sources.
5. Multi-point monitoring and control, data acquisition, centralized display processing. A monitoring master station can simultaneously monitor and control multiple remote stations, which is determined by the actual number of wells and booster pumps in the water source. The operator of the power plant network control room can simultaneously monitor the operation conditions of the remote water source, and start and stop the operation of the water source motor according to the actual situation.
6. The system should respond quickly and have good real-time performance. The use of preemptive real-time multi-tasking can collect a variety of analog electrical information of the motor, and can accurately and accurately reflect the running status of each motor through analysis of various analog quantities. The order of processing is determined according to the priority of the task and the importance of the data. Manual control commands have the highest priority. Reading commands such as real-time harmonics has a lower priority. The amount of event data is important and needs to be read in a timely manner. The normal electrical operation parameters are the next and can be read at regular intervals.
7. The system should have a good human-machine interface. The operating personnel can monitor the current operation status of the well motor and each booster pump through the screen. When the parameter exceeds the limit, the alarm information is displayed in a variety of ways. The use of color, sound and other media to remind the operator to pay attention to, and the parameters of the over-limit conditions to record and accumulate, in order to carry out accident analysis, improve the motor's safe operation level play an important role The role. Different operators should be given different operating rights, so that the rights and responsibilities can be clearly defined. Can promote the role of different system maintenance personnel to complete their work, but also to facilitate the work of assessment and accountability. The operator's operation interface should be flexible, convenient, intuitive, simple, and easy to use. It should meet the requirements of skilled operation after short-term training.
8. The system should be easy to upgrade and expand. System hardware selection should fully consider the advanced and reliability to ensure the investment has long-term effectiveness. The system software should be considered for convenient expansion and configurability. The user can easily increase or decrease the system control unit according to actual needs. The system can control the maximum number of intelligent front-ends. The maximum controllable number of 485 fieldbuses is (10 485 busses): 320; the maximum controllable number of wireless modes is: The theoretical value of each serial port is: 9999.
9. The project has low implementation costs, low operating costs and easy maintenance. The implementation of the system should maximize the protection of past investment, reduce new investment, low cost during operation, and facilitate maintenance.
Third, the implementation of the program 1. The overall design of the system combines the main station and the substations. The main station is set up in the pumping station. The main station and the substations in the pump room are connected through the 485 bus. Each well substation communicates with the main station through the radio station, and the main station and the power plant network. The remote station of the control room also communicates through the radio station. The specific structure is as follows:
2. The system hardware is configured on the system hardware configuration. To achieve the organic integration of decentralization and concentration, the specific configuration is as follows:
2.1 The data acquisition equipment adopts the intelligent measurement and control front-end (ACM3720) equipment. Each measurement and control equipment can be installed on the site in a scattered manner. The anti-interference ability is strong, the measurement accuracy is high, and the operation is stable. There are 232 and 485 bus communication interfaces, which can meet the requirements. Rapid data collection requirements.
The main performance of the intelligent monitoring and control front-end (ACM3720) device:
A, input PT, CT for telemetry (more than 300 parameters can be calculated using AC sampling algorithm)
B, 4-way access as remote signaling (resolution of 1ms, each channel can be used for pulse counting)
C, 3 relay outputs can directly control the switch's split/close relays, realize remote control operation, and can realize multiple control and protection functions (over-current, quick-break, over-voltage, over-speed, etc.) Load, etc.)
D. One auxiliary voltage input (Vaux) can measure non-electrical energy such as temperature E, SOE function (100 events can be continuously recorded with a resolution of 1ms)
F, RS485/RS232 communication port measurement accuracy: current, voltage 0.2; power, electrical energy 0.5 The device has a high degree of reliability, strong features, with a good performance and price ratio.
2.2 As the booster pumping station is close to the main station, the monitoring of each pump is directly connected to the monitoring master station using the 485 bus cable, and the communication rate is up to 19200bps, and the data transmission is faster. Because the wells are dispersed and away from the monitoring master station, data communication between the master station and the substations is realized through the ultra-short wave wireless data transmission station. The transmission rate of 1200bps wireless data radio station has been able to meet the needs of monitoring. The digital radio station has stable and reliable time running, simple installation and easy maintenance. The remote station is located tens of kilometers away from the main station and is also a two-way data communication via a wireless data radio station. When the system is implemented, different types of instruments can be connected to the 485 bus to achieve simultaneous monitoring of various devices. The expansion of the system is good. Only by adding the ACM3720 device and the wireless data radio connected to it to the well requiring wireless remote control can the monitoring be realized.
2.3 Both the main station and the remote station adopt a new generation of industrial control computers, which have strong anti-interference ability, stable operation, dust-proof and high-temperature resistance, and are suitable for use in harsh environments to further enhance the reliability of the system.
2.4 The remote station reserved the network interface, which can realize multi-point monitoring after joining the power plant LAN. The remote station communication program design uses the socket UDP protocol to send data by broadcast. The remote station monitoring host is connected to the power plant LAN. Any computer on the LAN installed with client software can be based on Permissions to monitor or operate. Therefore, it will greatly facilitate the technical personnel of the power plant to know the actual conditions of the operation of the water source in a timely manner and facilitate the timely resolution of the problems arising from the treatment.
3. Operating System and Development Software In the system software configuration, the WINNT operating system was selected. WINNT is an operating system with multi-tasking, multi-threading, and high network security. It has stable operation and strong functions. It has a window interface, is easy to operate, and easy to use. It is suitable for use in monitoring systems. WINNT has achieved the C2 security level stipulated by the U.S. government. The WINNT security system borrows object-oriented design ideas. The internal security function not only protects the NT operating system, but also protects the application against attacking bad applications. It also plays a role in virus protection.
3.1 Software design The data collection of communication program adopts the method of interrupting receiving data, which makes the data collection more timely and efficient, and improves the operating efficiency of the entire system.
3.2 Software design The communication program is designed so that the instrument control and data collection are processed according to a prioritized polling method so that the most urgent needs of the user are treated with the highest priority.
3.3 Software design Communication with remote substations in the communication program uses a centralized transmission method, which transfers all required data to remote substations at one time, reducing data traffic and improving communication efficiency.
3.4 The communication program adopts multi-line method and high-performance data collection mechanism.
3.5 Communication software Management software data communication adopts the non-connection-oriented UDP protocol, retains the network interface, can connect with the management information network, and transmit the real-time data directly to the management network to realize real-time data sharing. The advantage of using UDP over connection-oriented TCP is that data can be transmitted without having to establish a connection, and data loss due to unplanned connection interruptions need not be considered.
3.6 Develop a multi-window display management program. Using shared memory technology to achieve rapid refresh of real-time data and each task independently of each other.
3.7 The management program assigns different operation authority to different operators, so that the rights and responsibilities are clearly defined. All operations of the operator are recorded by the system, which promotes the different system maintenance personnel to complete their work and facilitates work assessment.
IV. Introduction to the Development Process 1. July 1998 - August 1998 collected data and system design.
2. September 1998, wireless data transmission equipment selection and field communication test, close distance and long distance. Solve the problem of delay after RTS of digital radio station.
3. The development and debugging of communication programs based on PML protocol from October 1998 to December 1998.
4, January 99-April 99 monitoring software development and debugging.
5. In May 1999-May 1999, the system was installed and debugged on site, and the system was put into operation at the Longkou Power Plant.
Fifth, the key to solve the technology 1, wired and wireless methods organically combined. The design scheme can not only meet the stand-alone application of the main station and the operator station on the same machine but also meet the requirements of multiple operator stations.
2. Improve the wireless modem, increase the RTS signal delay circuit, and solve the problem that data communication between the intelligent measurement and control front-end and the wireless data transmission station cannot be performed normally.
3, to achieve a multi-point monitoring and control. Not only can the water control and control room control all the wells, the power plant network control room operators can also remotely control water wells in water sources that are 30 kilometers away.
4, through real-time power factor judgment analysis, to achieve water level alarm, and can achieve automatic protection trip.
5. Communication program development based on a dedicated communication protocol. The network communication program must ensure the accuracy of the data and ensure the real-time data transmission. Reasonable data structures and good implementation algorithms are the key to the development of communication programs. The compatible use of different types of instruments on the same network is one of the problems that high-performance communication programs need to solve. The communication program can be compatible with the 485 bus master-slave communication mode and wireless broadcast point-to-multipoint mode.
6. Main features of the system Distributed integrated automation system based on industrial fieldbus and wireless broadcast communication.
2. Software and hardware control loops prevent misoperation logic design. Combining local operation with local operation and remote operation, it ensures the safety of operation, maintenance and overhaul by preventing misoperation logic. Achieve multi-point monitoring and control. Not only can the water control and control room control all the wells, the power plant network control room operators can also remotely control water wells in water sources that are 30 kilometers away.
4. The software realizes the well water level alarm and can realize automatic protection tripping.
5. System reliability, high degree of automation.
The measurement and control unit integrates data acquisition, calculation, control, and protection intelligence. System failure does not affect the normal operation of the local measurement and control unit. Failure of a local measurement and control unit will not affect the operation of other measurement and control units.
6. The installation workload of the system is small and the debugging time is short.
Simply connect the pump room collection device to the main station computer via a communication cable. The water well substations only need to add control instruments and wireless data radio stations, and they can use a unified communication protocol to send large amounts of data to computers. This technology greatly reduces the on-site workload and capital investment.
7. The system is easy to use and easy to maintain.
System man-machine interface is good, only need to carry on the brief introduction to the operator, the operator can use skillfully.
8. System configuration flexibility, scalability.
According to the specific needs of the system can be cut, 485 bus way to monitor up to a total of 10 network 320 monitoring and control unit; wireless theoretically, each serial port can control up to 9999 measurement and control unit; there is a dedicated master station and can have one or more Remote station.
This project was completed under the strong support and cooperation of the Longkou Power Plant. It was put into operation in Longkou Power Plant in June of 1999 and has achieved good application results. Since the system adopts an engineering and standardized development model, it adopts a distributed structure combining industrial field bus and wireless broadcast communication. It has a scientific design, complete functions, good versatility and scalability, and is easy to use and maintain. Various types of thermal power plants and environmental monitoring, decentralized monitoring and other fields have very broad prospects for promotion and application. With the further promotion and application of the product, it will play a greater role and generate more social and economic benefits.
3D Printing Auto Production Line
3D Printing Auto Production Line,3D Printed Solid Sand Mold,Resin Sand Molds For Casting,Small Build Volume 3D Printer
Guangdong Fenghua Zhuoli Technology Co., Ltd , https://www.fhzl3dpequip.com