0 Preface
220kV Handan Iron and Steel Songshan Station is one of the four major projects invested by Handan Iron and Steel in 2000. It is a comprehensive automatic substation with high voltage level, large capacity and advanced technical equipment. The total capacity of the three transformers is 170MVA. The 220kW system consists of a single-supply single-segment segment with a fully enclosed SF: combination switch (GIS). It consists of 3 circuit breakers with 33 knife gates divided into 7 intervals. The G1S switch is equipped with two sets of five anti-locking devices, one for the conventional wire hard contact type lock and the other for the Siemens SIMATICS7-300 type PLC program control device. The device is set by the PLC to check the interlock condition check program, and it is always checked whether the interlocking condition satisfies the switching operation requirement. Only when the switching operation requirement is met, the operation command is executed, and the switching state of the 33 knife gates can also be performed by the PLC system. Monitor and remotely control.
1 system composition
The main components of the PLC system are: 7 ET200M distributed IO stations as peripheral devices, connected to the CPU315-2DP template with integrated PROFIBUS-DP interface via PROFIBUS-DP field bus, and then through communication templates and protocol converters and substations The integrated automation network (LonWorks) is connected. The system structure is shown in Figure 1.
The seven ET200M distributed I/O stations in the figure are distributed in 7 intervals, each interval is connected by PROFIBUS-DP cable, and then connected to the CPU315-2DP template with integrated PROFIBUS-DP interface. The PLC system switchboard is set first. Interval, thus forming a PLC system PROFIBUS-DP network. The substation monitoring machine communicates with the PROFIBUS-DP network. The CP341 communication template and the protocol converter with integrated RS-422/485 interface transmit and receive information in the form of messages.
2 PLC component introduction
2.1 power supply
The PLC uses SITOP power supply, which can input two voltages of 120-230VAC and 120-320VDC, and can output 24V/10ADC power supply. The station input voltage is 220VAC.
2.2CPU template
The SIMATICS7-300 PLC series has six CPU modules with different CPU performance and functions. This station selects the CPU3J5-2DP template. The template has a large program memory suitable for complex configurations that include both centralized and distributed peripherals. There are status and error LEDs on the front panel of the template, key switches for selecting the operating mode, MPI interface, memory slot, etc. In the normal operating state, only the "DC 5V" and "RUN" LEDs are lit green. The function of the memory slot is to protect the program from plugging up to 5l 2k bytes of memory card in the power-down state. 64k byte FLASH EPROM memory card.
2.3ET200M distributed I/O station
The substation PLC system has seven ET200M distributed I/O stations. Each ET200M distributed I/O station has two SM321 digital input templates and one SM322 digital output template. The SM321 digital input template converts the external signal level sent by the process to the S7-300 internal signal level. Its rated voltage is 24VDC, the "1" signal voltage is 15-30V, the "0" signal voltage is -3-5V, and the "1" signal input current is 7.5mA.
The SM322 digital output module converts the internal signal level of the S7-300 to the external signal level required by the process. It is rated at 24VDC, with a "1" signal with an output voltage of 24VDC and an output current of 0.5A.
3 Troubleshooting
Since the Songshan station of Handan Iron and Steel Co., Ltd. was put into operation in September 2000, the PLC anti-misoperation system has failed several times to remotely control the failure of the GIS knife gate in the background monitoring machine. This includes system failures caused by hardware, software, communications, connections, etc.:
(1) Because the station's PLC anti-misoperation system input power is 220VAC, once the AC power loss, it will cause the ET200M distributed I/O PLC system to "dead", even if the AC power returns to normal, it can not be automatically restored. normal status. In this case, the station power supply is first restored to normal. Secondly, the key switch of the CPU front panel selection operation mode is changed from "RUN" to "STOP" and then back to "RUN", that is, the power is restored. The PLC system can be restored to normal.
(2) The set of PLC anti-misoperation system adopts event triggering mode. To properly operate the knife gate of the GIS room on the background machine, it is necessary to make the 7 remote "local/local" control handles to the "remote" position. If there is a different control handle position, the remote control command of the background monitor will be blocked by the control unit, and the remote command cannot be realized. Therefore, before the remote control, each interval "remote/local" control handle should be hit to the "remote" position, and the remote command can be realized.
(3) The communication between the LonWorks network and the PLC system of the station is transmitted and received by the CSN022A protocol converter of Xu Jifang in the form of "one question and one answer" message. At the beginning of the operation of the station, all the message information of the LonWorks network was sent to the PLC system, which caused the PLC system to crash due to the inability to process so much information, causing the knife gate operation command to be unsuccessful. Later, the message sent to the PLC system is filtered, that is, the message information unrelated to the operation of the PLC system is filtered, and then sent to the PLC system. After this "information filtering" process, the speed of executing the command by the PLC system is accelerated, and there is no phenomenon that the PLC system crashes due to the information "carrying the car".
(4) The 7 intervals of the PLC anti-misoperation system are in series mode. Therefore, if one interval of the PLC unit crashes, it will affect the operation of all PLC systems. The first interval of the PLC anti-error operating system switchboard detects whether the 7-interval PLC system extension is normal, and if all the extensions are normal, the knife gate operation can be performed. If one of the PLC system extensions crashes, the operation of the knife lock is blocked. Therefore, if an extension crash is found, the total interval of the first interval is also reset, so that the PLC system can be restored to normal.
(5) Sometimes there are some false alarms in the background machine, and the position and actual position of the GIS knife gate displayed on the monitoring screen of the background machine are different. For example, when there is no operation, when a knife is in the position, the background machine is displayed in the position. When these situations occur, it is not the fault caused by the PLC system itself, but the cable joint of the input loop of the PLC system is loose, causing the PLC system to detect that the knife gate is in the position, so the tool gate is uploaded to the background machine through the communication template. Quantile information. This situation is relatively easy to occur, and the processing method is also very simple, as long as the loose connector is tightened.
4 Conclusion
The Siemens SIMATICS7-300 PLC system at Songshan Station of Handan Iron and Steel Co., Ltd. has not experienced any accidents caused by malfunction of its own system for three years, and has high reliability.
220kV Handan Iron and Steel Songshan Station is one of the four major projects invested by Handan Iron and Steel in 2000. It is a comprehensive automatic substation with high voltage level, large capacity and advanced technical equipment. The total capacity of the three transformers is 170MVA. The 220kW system consists of a single-supply single-segment segment with a fully enclosed SF: combination switch (GIS). It consists of 3 circuit breakers with 33 knife gates divided into 7 intervals. The G1S switch is equipped with two sets of five anti-locking devices, one for the conventional wire hard contact type lock and the other for the Siemens SIMATICS7-300 type PLC program control device. The device is set by the PLC to check the interlock condition check program, and it is always checked whether the interlocking condition satisfies the switching operation requirement. Only when the switching operation requirement is met, the operation command is executed, and the switching state of the 33 knife gates can also be performed by the PLC system. Monitor and remotely control.
1 system composition
The main components of the PLC system are: 7 ET200M distributed IO stations as peripheral devices, connected to the CPU315-2DP template with integrated PROFIBUS-DP interface via PROFIBUS-DP field bus, and then through communication templates and protocol converters and substations The integrated automation network (LonWorks) is connected. The system structure is shown in Figure 1.
The seven ET200M distributed I/O stations in the figure are distributed in 7 intervals, each interval is connected by PROFIBUS-DP cable, and then connected to the CPU315-2DP template with integrated PROFIBUS-DP interface. The PLC system switchboard is set first. Interval, thus forming a PLC system PROFIBUS-DP network. The substation monitoring machine communicates with the PROFIBUS-DP network. The CP341 communication template and the protocol converter with integrated RS-422/485 interface transmit and receive information in the form of messages.
2 PLC component introduction
2.1 power supply
The PLC uses SITOP power supply, which can input two voltages of 120-230VAC and 120-320VDC, and can output 24V/10ADC power supply. The station input voltage is 220VAC.
2.2CPU template
The SIMATICS7-300 PLC series has six CPU modules with different CPU performance and functions. This station selects the CPU3J5-2DP template. The template has a large program memory suitable for complex configurations that include both centralized and distributed peripherals. There are status and error LEDs on the front panel of the template, key switches for selecting the operating mode, MPI interface, memory slot, etc. In the normal operating state, only the "DC 5V" and "RUN" LEDs are lit green. The function of the memory slot is to protect the program from plugging up to 5l 2k bytes of memory card in the power-down state. 64k byte FLASH EPROM memory card.
2.3ET200M distributed I/O station
The substation PLC system has seven ET200M distributed I/O stations. Each ET200M distributed I/O station has two SM321 digital input templates and one SM322 digital output template. The SM321 digital input template converts the external signal level sent by the process to the S7-300 internal signal level. Its rated voltage is 24VDC, the "1" signal voltage is 15-30V, the "0" signal voltage is -3-5V, and the "1" signal input current is 7.5mA.
The SM322 digital output module converts the internal signal level of the S7-300 to the external signal level required by the process. It is rated at 24VDC, with a "1" signal with an output voltage of 24VDC and an output current of 0.5A.
3 Troubleshooting
Since the Songshan station of Handan Iron and Steel Co., Ltd. was put into operation in September 2000, the PLC anti-misoperation system has failed several times to remotely control the failure of the GIS knife gate in the background monitoring machine. This includes system failures caused by hardware, software, communications, connections, etc.:
(1) Because the station's PLC anti-misoperation system input power is 220VAC, once the AC power loss, it will cause the ET200M distributed I/O PLC system to "dead", even if the AC power returns to normal, it can not be automatically restored. normal status. In this case, the station power supply is first restored to normal. Secondly, the key switch of the CPU front panel selection operation mode is changed from "RUN" to "STOP" and then back to "RUN", that is, the power is restored. The PLC system can be restored to normal.
(2) The set of PLC anti-misoperation system adopts event triggering mode. To properly operate the knife gate of the GIS room on the background machine, it is necessary to make the 7 remote "local/local" control handles to the "remote" position. If there is a different control handle position, the remote control command of the background monitor will be blocked by the control unit, and the remote command cannot be realized. Therefore, before the remote control, each interval "remote/local" control handle should be hit to the "remote" position, and the remote command can be realized.
(3) The communication between the LonWorks network and the PLC system of the station is transmitted and received by the CSN022A protocol converter of Xu Jifang in the form of "one question and one answer" message. At the beginning of the operation of the station, all the message information of the LonWorks network was sent to the PLC system, which caused the PLC system to crash due to the inability to process so much information, causing the knife gate operation command to be unsuccessful. Later, the message sent to the PLC system is filtered, that is, the message information unrelated to the operation of the PLC system is filtered, and then sent to the PLC system. After this "information filtering" process, the speed of executing the command by the PLC system is accelerated, and there is no phenomenon that the PLC system crashes due to the information "carrying the car".
(4) The 7 intervals of the PLC anti-misoperation system are in series mode. Therefore, if one interval of the PLC unit crashes, it will affect the operation of all PLC systems. The first interval of the PLC anti-error operating system switchboard detects whether the 7-interval PLC system extension is normal, and if all the extensions are normal, the knife gate operation can be performed. If one of the PLC system extensions crashes, the operation of the knife lock is blocked. Therefore, if an extension crash is found, the total interval of the first interval is also reset, so that the PLC system can be restored to normal.
(5) Sometimes there are some false alarms in the background machine, and the position and actual position of the GIS knife gate displayed on the monitoring screen of the background machine are different. For example, when there is no operation, when a knife is in the position, the background machine is displayed in the position. When these situations occur, it is not the fault caused by the PLC system itself, but the cable joint of the input loop of the PLC system is loose, causing the PLC system to detect that the knife gate is in the position, so the tool gate is uploaded to the background machine through the communication template. Quantile information. This situation is relatively easy to occur, and the processing method is also very simple, as long as the loose connector is tightened.
4 Conclusion
The Siemens SIMATICS7-300 PLC system at Songshan Station of Handan Iron and Steel Co., Ltd. has not experienced any accidents caused by malfunction of its own system for three years, and has high reliability.
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