Zhengzhou Industrial Safety Vocational College from the rapid development of modern control technology and computer technology, automatic control technology has been widely used in power equipment, making the entire power equipment control process to achieve computer monitoring, control and management, and completed high quality Low cost, stable and reliable operation mode. PLC has the advantages of good versatility, high reliability, flexible installation, convenient expansion, high cost performance, etc., and its bus and network capabilities are getting stronger and stronger, and it can easily form a control system with the host computer. Therefore, PLC has obtained on the power equipment. widely used. Using the PLC control system not only can easily complete the functions of sequential logic, motion control, timing control, counting control, digital operation and data processing, but also can establish the connection with the digital and analog quantities of various production machines through the input and output interfaces. Second, the main problem of automatic control technology applied to power equipment is a typical fault of the sensor. The PLC monitors external devices through sensors, limit switches, etc., and if the sensor components fail or malfunction, the PLC will also malfunction or not operate. Common faults of the sensor are: the sensor is stuck, the output of the sensor does not change with the measured value, and maintains a constant output value; when the sensor is pulsed, the output of the sensor suddenly changes to a short time and then returns to normal; The gain of the sensor changes or the output gain of the sensor is attenuated or increased; when the sensor is disconnected, the sensor is in an open state; the constant deviation of the sensor, the output signal of the sensor and the measured value are largely deviated. Hardware design failure. For the use of the original hardware, the hardware is fully developed and utilized in the original design system to realize new functions. Software failure. Completely program some subroutines of the original software, increase and strengthen the fault diagnosis data storage and communication functions, and facilitate system fault diagnosis. Third, the automatic model control technology in the application of power equipment initial model simulation. A commonly used and effective predictive control method in condition monitoring is the use of time series models for state simulation prediction. In a power device, if the time series of a certain state change of the device is regarded as a random sequence and the existing observations are taken as samples, the required work is to establish a time series model by using the sample data, and when the model parameters are determined, Current and historical observations can be used to predict the future state of the device. The fuzzy dynamic model is established, and the small area control model is used to replace the large area control model to improve the system control and response accuracy, so as to obtain the high-precision dynamic response of the full control range, and ensure that the system can meet the production requirements. Use the observer to troubleshoot. Observers and filters for fault diagnosis essentially use state reconstruction to implement state estimation. The reconstruction and state-related residual information includes fault information, and fault detection and isolation based on residual analysis. When the diagnostic strategy is that the sensor is working normally, the residuals of each observer are only affected by the noise and fluctuate around the value of 0. The failure of a certain sensor will be reflected in the residual of the observer. Fault detection technology is used for fault detection. The most basic and effective method of fault detection is to detect the degree of error of the measured signal from the expected value. This detection technique is usually implemented by setting the upper and lower limits of the measured signal. When the value of the measurement signal falls within the interval set by the upper and lower limits, the signal is considered normal, and conversely, the signal is considered to be abnormal. In addition, the rate of change of the measured signal is also an effective method for detecting the fault state. If the rate of change of the signal is higher than the upper limit or lower than the lower limit, the system is considered to be in a fault state. Closed loop identification control. Closed-loop identification can be divided into indirect identification method and direct identification method. The indirect identification method first obtains the closed-loop system model. Based on this, the controller model on the feedback channel is used to derive the forward channel model. The direct identification method is used. The input and output data of the forward channel directly establishes the digital model of the forward channel, and the controller model of the feedback channel can be unknown. The system control requirements identification must be carried out in a closed-loop state. For example, when the parameter adaptive control problem is studied, the identification and control are organically combined. At this time, the identification must be performed in a closed-loop state to modify the control law in real time. Actuator troubleshooting. The actuator is a weak link in process control, and its failure is one of the common faults in the control system. The common faults of the actuator are that the deviation between the feedback and the command is too large, the actuator output has a sudden or slow-changing deviation, the gain is gradually attenuated, and the actuator oscillation actuator is stuck and the like. When the actuator has a viscous-sliding failure phenomenon, it is diagnosed according to the change of the frequency distribution of the speed change event in the process. For example, when the viscous-sliding occurs, the velocity frequency distribution diagram changes obviously, and the mean value of the valve stem velocity and the root mean square are utilized. Increased to diagnose such a fault, can be easily diagnosed. The relationship between the two depends on the shape of the distribution frequency map. In theory, the ratio between the velocity mean and the root mean square is related to the shape of the frequency profile of the valve stem velocity. Develop new hardware devices. The hardware design of the automatic control system device has many functions, among which the main online monitoring automatic adjustment system adjusts the quality and gives evaluation, such as attenuation rate, transition process time, overshoot, static deviation, dynamic deviation and other indicators; Closed-loop identification of the system; whether the diagnostic control system is in an optimal setting state, analyzes its cause, and gives suggested measures; determines whether some important signals in the control system work normally, gives an alarm and separates the faulty sensor, makes recommendations and should take Measures; determine whether the actuator in the control system is working properly, and if the actuator fails, give corresponding alarms and suggestions. The design of the equipment hardware can be used in a variety of ways, so the development of new hardware devices can achieve multi-functional control. Develop new programs. The software of the control system can be divided into three major data acquisition modules: graphic display module, online diagnostic analysis module and historical data analysis module. Among them, the graphic display and online analysis program are the core part of the software. As the main program of the whole software, the data acquisition program is the precondition of the software operation, and is the background program of the whole software; the historical data analysis program is used as the offline analysis tool of the software. With the continuous development of power system technology and equipment, the requirements for reliability and safety of power equipment are also constantly increasing. It is urgent to quickly and accurately diagnose faults on power equipment to prevent accidents. However, with the enlargement and complication of power system equipment and the increase of power running equipment, its operating state is constantly changing. The task of implementing power equipment fault prediction and diagnostic control is in the process of running power equipment or basically not disassembling. In the case, using various measurement, analysis and discriminating methods, combined with the historical condition and operating conditions of the equipment, to clarify the objective state of the equipment, to provide a reliable basis for finding faults and solving faults in advance. In this paper, the author points out the main problems at present through the research on the automatic control system of power equipment, and proposes corresponding countermeasures, which establishes a certain foundation for the better application of automatic control system in power equipment. 13 Rayon Sarongs Beach Sarong,Rayon Satin Plain Dyed Foil,Rayon Satin Pd With Design Foil,Rayon Satin Flower Foil Shaoxing Shangda Textile Co., Ltd , https://www.shangdatex.com