PLC or programmable logic controller is a digital computer used for automation of processes in many industries such as mining, production management and transmission of electricity, then wood processing industry, metal industry and many others. Today, PLC controllers can realize the functions of data transmission between two or more controllers, which enables synchronized operation of machinery, then advanced features in automation such as PID control, control stepper motors and many others. So it does not matter whether a simple start-up and monitoring of the engine or a complex operation PLC controller can respond to request. This is certainly a solution that consists of two cabinets containing equipment and automation equipment for the connection of a generator to the grid.
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Abstract PLC is proposed as the essential tool in many different applications. In this paper, the PID controller is designed to control Motor Speed based on incoming information of system and Auto tuning. The control system is simulated by powerful software Matlab and Simulink. Simulation results also show better performance of motor that reduce the rise time, steady state error and overshoot and increase system stability.
HMI monitor display the coefficients of the PID controller and desired speed and motor speed and motor speed versus time graph. One of the direct current motors are motors with permanent magnet direct current PMDC. Wiring scheme of control system is shown in fig. Introduction Due to the fast performance of DC motors, these motors are regulated in a wide range of speeds and can be used in many applications.
The main advantage of using DC motors in today's world is the ability to easily control the speed and angle of the motor. The controller has more advantages than conventional control circuits. The benefits can be noted such as reducing the size of the control panel, very low energy consumption, Durable Equipment, Proper operation in the worst cases. Using PLC for controlling industrial systems is initiated in and, its development has been greatly accelerated in recent years.
We used PLC to control motor speed. At first, motor speed is transferred to PLC by shaft encoder, then PLC according to the program and PID controller generate the control signal to reach the desired speed. According to the received control signal, drive transfer required voltage to the motor. Every moment, signal of shaft encoder is. The PID controller diagrom in this circuit is shown in fig.
We should tunned PID parameters for receiving best stability and overshoot and settling time at manual and simulation. Shaft encoder sense the speed and set the soutable speed. The simulation is obtained by calculating the system transfer function.
To better evaluate the performance of the controller system, the change of control coefficients in the simulation are shown in fig.
According to fig. By suitable setting coefficients Ki and Kd and Kp, setting time, steady state error and overshoot is reduced. Step response of. If a DC motor equivalent circuit is as follows:. Increase the value of Kp from 0 to a critical value, Kcr at which the output first exhibits sustained oscillation.
Ke and Kt are equal amount in SI. According to the 5 , the current is: 7 According to the 6 , 7 : 8. Hardware Implementation In this article, speed control of direct current electric motor designed and simulated and made. The main Required components to make are shown in fig. According to 8 , Voltage input to output speed ratio is as follow: 9 As a result, we have: 10 Dc motor parameters are given in Table 1. The parameters and the amount of these are determined.
Ziegler and Nichols proposed rules for determining values of the proportional gain Kp, integral time Ti, and the derivative time Td based on transient response characteristics of a given plant. For the Ziegler-Nichols. We used high speed counter and auto tuning for programming PLC.
HMI allows to us, display moment to moment status of process and important parameters and displays the error online. For receiving and transmission motor speed used shaft encoder. Here's another piece are used that called coupling. For the coaxial and transmission motor speed to shaft encoder because of heterogeneous between two shaft diameter, we need to coupling.
This piece was designed so that the input inner diameter 12mm and output inner diameter 6mm. Two screws at the junction of the two shafts are considered to prevent of freewheeling. The basis for the shaft encoder is used. Due to the lower elevation shaft encoder, we needed to a base for strength and to prevent vibrations.
Also a board made of MDF for mounting all components were considered, until all pieces are sturdy and without translocation.
Overarching theme construction of the. For example, the graph of motor speed for set value r. HMI's key perform defined operation. This key will not work if the function is not defined. Keys F1, F2, F3, F4 are set for a defined operation. The F1 key is set for increasing the Kp value by step The F3 , F4 keys are set for decreasing kp and set value, respectively. The F2 key is set for increasing the current value by step Class F is motor insulation type. With information such as load operational, motor efficiency and thermal increasing coefficient, the ambient temperature can be measured.
Ramp function as a control system to prevent engine operation at extremely low temperatures required. It is a negative value describing loss of velocity as a function of increased torsional load. From the motor data sheet, it can be seen that the no-load speed of the motor at volts is rpm. If the torque load is not coupled to the motor shaft, the motor would run at this speed.
The motor speed under load is simply the no-load speed less the reduction in speed due to the load. The proportionality constant for the relationship between motor speed and motor torque is the slope of the torque vs.
The motor current under load is the sum of the no-load current and the current resulting from the load. For DC motors, the output torque is proportional to the current going into the motor no matter what the motor speed.
The straight-line relation between torque and current is the torque-current curve as shown in fig. This graph is plotted for proposed circuit that is shown in fig.
We used the suitable power supply that equipped with filter and isolatation to noise from AC power don't transfer to the controller and its input and output and we used Shield of cable that one side of these are connected to ground. We designed path the cables properly. We consider the two ground systems, one for the PE and CE else that although both are ultimately connected to the ground network, but there are two distinct pathways. Control equipment is connected to CE ground. To determine the allowable temperature rise of the motor,.
Conclusion The designed control system can control the motor speed very quickly. The motor speed current value reaches to set value in a short time and very less overshoot and it is very. By comparing the simulation results of the system, before controlling and after that, we can conclude that many of the desired characteristics such as rise time and overshoot improve.
The results of simulation and hardware implementation show the improved performance of the system. Ziegler, N. Krishnan, B. Learn more about Scribd Membership Home. Much more than documents. Discover everything Scribd has to offer, including books and audiobooks from major publishers. Start Free Trial Cancel anytime. PLC Programiranje. Document Information click to expand document information Description: programiranje plca.
Date uploaded Jun 26, Did you find this document useful? Is this content inappropriate? Report this Document. Description: programiranje plca. Flag for Inappropriate Content. Download Now. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document. Figure 1. Wiring scheme 2. Every moment, signal of shaft encoder is Figure 2. The step response of system With Ki and Kd small Figure 4. The step response of system With increasing Kd Figure 6. Step response of the system which holds approximately DC motor parameters parameters value