Shijiazhuang Zhongjia Slurry Pump Co.,Ltd. , https://www.zjoemparts.com
1. The electrical monitoring ECS ​​system is included in the scope of the DCS
AVR system high voltage factory power supply system;
High-voltage start/standby power system (#2 machine part);
Main plant low-voltage factory power supply system;
Auxiliary workshop power supply 6kV side switch;
380V factory power supply switching system Main and high-voltage factory motor (controlled by thermal system);
UPS system (surveillance);
220V, 110V DC system (surveillance);
Security power system (including diesel generator, Red Star security power supply);
Automatic quasi-synchronization system.
6KV factory power fast switching device Microcomputer protection and automatic device information communication Second, the function of the electrical monitoring ECS ​​system (A) the electrical monitoring ECS ​​system control mode 1, the generator system can be achieved through the sequence control and network program automatic control The generator shall be boosted from zero until the grid is connected with the initial load. It may also be controlled by a soft hand. It can also achieve automatic shutdown of the generator through sequence splitting.
2. In the same period, the system can achieve the same period (SID-2) J and the same period of the same period (the same period card) switch, giving priority to the use of the same period outside. At the same time keep operating habits, easy to operate.
3. For 6KV plant power supply system, program control or soft hand operation control can be performed according to the requirements of generator start and stop phases and normal operation phases, and the sequence program switching from working to standby or from standby to working power can be realized. Soft hand operation switch to ensure the unit safe operation or normal open and shut down.
4. For the 380V factory working power supply system, the original ECS with interlocking functions such as low-voltage tripping, working and backup, and self-casting is implemented. At the same time, different sequence logics can be used for live and uncharged bus conditions. Realize the automatic operation of high and low side switches.
5. For the security system, the relationship between the diesel engine self-start logic, the stand-by line of the diesel engine and the security section, and the lock-up between the diesel engine and the Red Star security switch can be automatically implemented.
It can display and record in real time (including accident sequence records) various data and status of normal operation, abnormal operation and accident conditions of generator-transmission system and plant power system, and provide operation guidance.
The occurrence of electrical faults (such as tripping of switches, etc.) can push out relevant screens, and corresponding alarm signals (such as relay protection action signals, etc.) appear on the corresponding screens, and provide an audible alarm for critical equipment accident trips and some major operations for operation. The staff quickly mastered the accident.
When the unit unit is out of service, the DCS can still monitor and operate the plant power system, that is, the related monitoring equipment may not be stopped.
All the single circuit breakers operated by the ECS, in addition to having the necessary interlocking functions, also have necessary locking measures to prevent erroneous operation; the switching device's state of splitting and closing, and the integrity of the control circuit are all monitored.
(II) Screen of electrical system monitoring (real-time dynamic display)
#2 generator and excitation system screen;
#2 machine factory electrical wiring diagram;
380V security power system principle wiring diagram;
380V dedusting section principle wiring diagram;
Chemical water I, II principle wiring diagram;
#2 UPS system principle wiring diagram;
220V DC system principle wiring diagram;
110V DC system principle wiring diagram;
01, 02 Startup change interconnection principle wiring diagram;
Generator active power, reactive power load curve and operating point display;
#2 machine electrical measurement parameter list;
#2 a list of electrical equipment operating conditions;
#2 Machine ECS sound and light alarm list;
III. Features of #2 Electrical Monitoring ECS ​​System Since the end of the 1990s, electrical quantities have begun to enter DCS and have undergone two phases: supervision alone and local control. Compared with domestic power plants of the same type, the electrical monitoring ECS ​​system of #2 has made new developments and breakthroughs on the basis of the original, and has the following characteristics:
1. The scope of inclusion of DCS has been further expanded.
In addition to relay protection and some electrical special automation devices, the electrical system is almost entirely incorporated into DCS.
In the central control room, only the generator-circuit breaker emergency trip button, the generator magnetic field breaker trip button, the diesel generator emergency start button, the 6KV operation, and the standby line all remaining electrical operation switches, buttons, electrical instruments, electrical All the light cards are cancelled. At present, they should be more thorough in the domestic power plants of the same type. At the same time taking into account the reliability and DPU crashes and other unexpected conditions in the security power system still retains a set of hard wiring.
2. The ECS system begins to participate in the adjustment of the electrical system. The control of the ECS system basically only controls the opening and closing of the electrical switch or the contactor. The #2 ECS system also participates in the regulation of electrical systems. According to the need to give AVR magnetization, demagnetization command, adjust the AVR given value, to achieve the purpose of adjusting the generator terminal voltage;
According to the voltage and frequency difference between the system and the generator, the output voltage and frequency of the generator can be adjusted, and automatic quasi-synchronization can be achieved.
3. Communication protection and automatic devices of ECS and protection and automatic devices send information into ECS system through communication protocol, so that it is convenient to see various information of protection and automatic devices from CRT, analyze accidents, and protect The understanding of health conditions offers great convenience. However, the use of this function in #2 is not yet very successful.
4. The function of automatic devices that can be used for some electrical purposes. In the ECS system, the BZT card and the SYN card are also used. The self-investment of low-voltage plant power supplies and the automatic quasi-synchronization of generators on-grid power supply are all achieved through self-provisioning and concurrent cards.
Fourth, the electrical monitoring system of several ideas:
1. Strengthening communication with protection and automatic devices Electrical relay protection and special automatic devices are connected to ECS by hard wiring. Most of them are comprehensive alarms or fault signals. Operators only know the fault or action of a certain device, but they do not know exactly. What kind of fault or action signal? In fact, relay protection and special automatic devices have been computerized with a communication interface. If ECS manufacturers can communicate with the main domestic electrical relay protection and special automation device manufacturer's specifications, ECS will be able to provide more information to the operating personnel, to facilitate the operation personnel to grasp the equipment operation situation in time, and make prompt decisions. At present, some integrated power protection devices for domestic plants have comprehensive functions such as protection, control, acquisition, metering, and wave recording. If the ECS can be accessed by communication, the on-site transmitter and power meter can be canceled. ECS I /O points, cables can also be reduced, which saves a lot of investment.
2. The switching of perfect plant power from the investment card function requires the BZT card to realize, among which the low voltage criterion should be taken into consideration, and the BZT card can realize the self-investment. There is no problem in the time requirement, but the low-voltage trip circuit Due to the DPU logic implementation, it is impossible to achieve the millisecond-level delay in time, which causes some troubles in conjunction with the operation time of other devices, and the BZT card cannot be completed alone when the DPU is powered off or crashes. Investment process. Hope that the manufacturers can gradually improve.
Application of Electrical Monitoring System (ECS) in #2 Machine
Our plant #2 was assembled at the end of the 1980s with a stand-alone capacity of 300 MW, a low degree of automation, a large number of equipment must be manually adjusted, the equipment failure rate is high, the maintenance volume is large, and the unit operating efficiency cannot reach a high level. With today's ever-changing technological development, electrical control equipment has not kept up with the pace of market changes, and it cannot adapt to the changing needs of modern operations. From March to May of this year, using the opportunity of overhaul of unit #2, the electrical control equipment system was reconstructed: Xinhua XDPS-400 distributed control system was adopted to coordinate the control of the unit units, and the electrical monitoring system was used as the unit DCS system. One of the subsystems - ECS system, to achieve control of the electrical system in the transformer and factory power supply system. The ECS system, like the MCS, FSSS, etc., has a dedicated on-site acquisition/control device (including I/O interface) and a dedicated controller (DPU), and is configured for reliable redundancy. After the guidance of experts from Xinhua Company, we worked together in design, installation, and debugging. The #2 machine has successfully connected to the grid successfully. The ECS system is currently operating in a good condition.