Proportional control

About: Proportional control is a research topic. Over the lifetime, 3756 publications have been published within this topic receiving 49050 citations.

Simulator of Water Tank Level Control System Using PID-Controller

Abstract: The difficulty of a Water Tank Level Control System (WTLCS) is often operates under unstable condition such as above setpoint level or below setpoint level. The unstable condition normally contributes to damage of devices and equipments of a process plant. However, this problem can be solved by introducing feedback controller by visualizing it using interactive simulator. One of the feedback controller is a Proportional (P) controller. Nonetheless, the P controller has drawbacks to control the non-linearity of a water level. The aim of this paper is to present the implementation of a PID controller to control virtual WTLCS. The P controller and PID controller is implemented in a WTLCS virtual model which has been developed using Microsoft Visual Basic 6.0 (VB). The both P and PID controller have been compared. The simulation result shows that the PID controller gives better control system response as compared to P controller.

An Input/Output Approach to the Optimal Transition Control of a Class of Distributed Chemical Reactors

Abstract: An input/output approach to the optimal concentration transition control problem of a certain type of distributed chemical reactors is proposed based on the concept of residence time distribution, which can be determined in practice by using data from experimental measurements or computer simulations. The main assumptions for the proposed control method to apply are that the thermal and fluid flow fields in the reactor are at pseudo-steady-state during transition and that the component whose concentration is to-be-controlled participates only in first-order reactions. Using the concept of cumulative residence time distribution, the output variable is expressed as the weighted sum of discretized inputs or input gradients in order to construct an input/output model, on the basis of which a constrained optimal control problem, penalizing a quadratic control energy functional in the presence of input constraints, is formulated and solved as a standard least squares problem with inequality constraints. The effectiveness of the proposed optimal control scheme is demonstrated through a continuous-stirred- tank-reactor (CSTR) network and a tubular reactor with axial dispersion and a first-order reaction. It is demonstrated through computer simulations that the proposed control method is advantageous over linear quadratic regulator (LQR) and proportional-integral (PI) control in terms of control cost minimization and input constraint satisfaction.

Comparison of methods for controllers design of single phase inverter operating in island mode in a microgrid: Review

Abstract: In recent years, new strategies of electric power generation are being developed and these are based on distributed generation systems ( DG ). With this new strategy of electric power generation based on renewable sources, there is a need to implement interfaces that allow the connection of these sources to the grid, as well as feed loads directly when operating in island mode or disconnected from the grid. Such interfaces are known as microgrids and the energy conversion systems that integrate them are very important. Therefore, the design of these units of energy conversion is a priority; therefore in this work we present the comparison of three methods of controllers design and the model of a single phase inverter for island mode operation in a microgrid. Particularly, the mathematical model is represented using transfer functions. This model describe the mathematical relationships that enable design in a simple and direct way the controllers of the different control loops that make up the energy conversion system. For the controller design in this operation mode, a conventional direct current method based on frequency method was first developed, from which a proportional-integral PI controller is designed. Second, an approximate method based on direct current to alternating current transformation ( dc-ac ), that allows the design of a proportional controller add generalized integrator ( P+IG ). This controller is obtained from the PI controller design in direct current. Third, an exact method is developed, which consists in applying a general methodology based on the frequency analysis. In particular, this work distinguishes the advantages of the second method, considering that its application allows the controllers design in a simple way for the different inverter control loops.

Microprocessor-based control of steel rolling mill digital DC drives

Abstract: Algorithms are presented for the digital control of double-loop DC machine drives used for applications where severe constraints on motor speed and position render conventional constant-torque or power control inadequate, such as in steel rolling mill drives. It is shown that the heavy current demand associated with maximal acceleration control can be reduced by using a form of proportional control where, in addition to the conventional inner-loop current feedback, a distance feedback term sets the high limiting value of the speed feedback signal, thus reducing the motor armature current. >

On time-optimal anti-sway controller design for bridge cranes

Abstract: In this paper, we analyze and discuss the time optimal control problem for bridge cranes. Specifically, we employ the geometric approach introduced in [12] to address the control issue without computing the analytic trajectory of the costate. As a second contribution, we show that an alternative approach based on a proportional controller accounting for the limits of the control action can be tuned to resemble to the time-optimal solution, but with simpler and more robust implementation. The above ideas are validated by means of some simulation examples.