Redundancy technology is a technology commonly used in the reliability design of computer systems, and is one of the most effective ways to improve the reliability of computer systems. In order to achieve high reliability and low failure rate, we usually use redundancy technology in the design and application of control systems. Reasonable redundancy design will greatly improve the reliability of the system, but it also increases the complexity of the system and the difficulty of design. The system with redundant configuration also increases the user investment. Therefore, how to carry out redundant design of control system reasonably and effectively is a subject worth studying. Redundancy is the addition of redundant equipment to ensure that the system works more reliably and safely. Redundant classification methods are diverse. According to the location in the system, redundancy can be divided into component level, component level and system level; according to the degree of redundancy, it can be divided into 1:1 redundancy, 1:2 redundancy. I, 1:n redundancy and so on. In the current situation of increasing component reliability, compared with other forms of redundancy, 1:1 component-level thermal redundancy is an effective and relatively simple, flexible configuration of redundant technology implementation, such as I/O card redundancy, power redundancy, main controller redundancy, etc. Therefore, most of the current mainstream process control systems at home and abroad use this approach. Of course, there are also successful examples of component-level or multiple redundancy combinations in some partial designs. The system operation is not affected by local faults, and the maintenance of faulty components has no effect on the function realization of the whole system, and online maintenance can be realized, so that the faulty components can be repaired in time. Redundant design increases the difficulty of system design. Redundant configuration increases the investment of the user system. However, this investment brings the reliability of the system, which improves the mean time between failures (MTBF) of the entire user system and shortens the average. Fault repair time (MTTR), therefore, it is necessary to apply redundancy to control systems in important situations. The so-called redundant power supply, that is, the backup power supply. The simplest solution is that the backup power supply is connected to the circuit power supply through a diode. In normal times, the circuit power supply voltage is slightly higher than the standby voltage and voltage minus the diode voltage drop. The diode is turned off and the standby power supply is not working. When the main power failure fails to supply power normally, The backup power is automatically put into operation. The Tianjin Junliangcheng Power Plant was started in 1960. Two 50MW units were built in the first and second phases, which were completed and put into operation in the early 1970s. Two 200MW units were built in the third and fourth phases, and all were put into operation in 1993. In the second phase, two 50MW units have completed the heating reform in 2004. In the first phase, two 50MW units have completed the circulating fluidized bed heating reform in 2005. At present, there are 8 units in the whole plant with an installed capacity of 1000MW, including 200MW for heating units and 800MW for pure condensing units. Among them, four 200MW units in the third and fourth phases have all been converted into DCS control. The DCS system adopts Guodian Zhishen GD99 distributed control system. The upper configuration software adopts the domestically developed GD99 configuration software, and the controller adopts Modicon Quantum Series 534 control. And I/O templates. D CS Network System Introduction Our factory DCS system has the following components: NPU1A and NPU1B are MODICON controller data exchange servers that are mutually active and standby. It is absolutely forbidden to withdraw from the operation during the operation of the unit. NPU2A and NPU2B are the primary source patrol data exchange servers, which are responsible for collecting a large number of sites. Monitoring data; HIS is the historical station, which is responsible for the collection and preservation of historical records and alarms; CS is the computing station, which is responsible for the network data exchange between DEH system, patrol station and DCS system; OPR1-OPR6 is the operator station, which is the operator monitoring And the operating platform; MIS is the MIS station, responsible for data communication with the plant-level MIS network. They are connected to the two HUBs via their respective dual NICs to form the actual redundant 100M star Ethernet. The NPU1A/1B uses the MB+ network to communicate with the lower controller. The controller and the I/O module are connected by a coaxial cable and a T-head to form an integral control system. Our factory DCS system has five pairs of controllers: CCS controller, EMCS controller, SCS controller, DAS controller, QS soda controller. They are responsible for controlling the related devices, and all controllers are connected to the MB+ network as shown below to form a complete DCS network control system. As shown in Figure 1 below: This figure uses a pair of CCS controllers as an example. I/O Module Power Failure The probability of failure of any kind of electronic device is objective. I have had a problem with the DCS template power supply CPS card damage, resulting in the loss of all module power supplies in the line. The DCS system is out of control, causing certain economic losses and adverse effects to the department and the company. The probability of human error is higher than that of a single power supply. Once the worker accidentally touches or misplaces the power switch of the power module CPS, or the power supply of the power supply template is de-energized, the consequences are equally serious. First, the I/O template redundancy configuration is expensive, and the cost pressure from the investor and the DCS manufacturer is very large, so it is extremely difficult to implement redundant configuration of the I/O template. Secondly, according to the system requirements and design conventions, only redundant or triple-configuration of signals such as drum water level, furnace negative pressure, and turbine speed are used. For a general important signal redundancy configuration, a large number of measuring points and sampling are required. And need to contact the design institute and the infrastructure unit in advance to determine the extension of the construction period and increase the cost. Finally, if it is an old unit transformation, it will be more difficult, such as whether to leave a reasonable sampling position, whether there are enough spare passages, increase the amount of maintenance costs, etc., so it is almost impossible to achieve. It can be seen from Figure 1 that our DCS control system is redundantly configured from the operator station, network switch, data server and controller. That is, the power of the active and standby devices is from the corresponding active and standby UPS power supplies. At the I/O module level, only the CPS114 single power card on the left side does not reach the redundant configuration. In this way, the safety and stability of the system are not in line with the requirements of the safety evaluation system of the thermal power generation control system. This is the deficiency and loophole of the original design of the system. Based on the above points, we need to transform the existing system from the aspects of system requirements and safety and reliability. Portable Wireless Speaker,Mini Wireless Speaker,Custom Bluetooth Wireless Speaker,Waterproof bluetooth speaker,Wholesale bluetooth speakers Shenzhen Konchang Electronic Technology Co.,Ltd , https://www.konchangs.com