Inherent nonlinearities like, deadband, stiction and hysteresis in control valves degenerate plant performance. Valve stiction standouts as a more widely recognized reason for poor execution in control loops. Measurement of valve stiction is essential to maintain scheduling. For industrial scenarios, loss of execution due to nonlinearity in control valves is an imperative issue that should be t...

Thermostatically controlled loads (TCLs) account for approximately 50% of U.S. electricity consumption. Various techniques have been developed to model TCL populations. A Highfidelity analytical model of heterogeneous TCL populations facilitates the aggregate synthesis of power control in power networks. Such a model assists the utility manager to increase the stability margin of the network. T...

This thesis deals with various aspects of coordinated voltage control in electric power systems. It consists of an introduction and six papers. The introduction contains a summary of the thesis and tutorials on voltage control and the search methods that have been applied. The first part deals with the coordination of cascaded tap changers in radial distribution feeders. Poor coordination cause...

Stiction is a nonlinear friction phenomenon that causes poor performance of control loops in the process industries. In this work, we develop a mixed-integer MPC (Model Predictive Control) formulation including valve dynamics for a sticky valve in order to improve control loop performance. The introduction of the valve nonlinearity into the model prevents the MPC from requesting physically unre...

A practical approach to design a feedforward-plus-proportional-integral-derivative (FPID) controller for accurate and smooth velocity control on a hydraulic linear actuator is presented. The integrated controller consists of a feedforward loop and a PID loop. The feedforward loop is designed to compensate for the nonlinearity of the electrohydraulic system, including the deadband of the system ...

Accuracy Includes linearity, hysteresis, repeatability ±0.25% of full scale ±1 least significant digit Display 4 readings per second nominal display update rate 4 digit LCD, 0.5" H main display 5 character 0.25" H alphanumeric lower display Alarm 1 and Alarm 2 LCD indicators and bi-color (red/green) LEDs Controls & Functions SEL Select and display alarm trip points TEST Alarm acknowledge, or to...

The benchmark active controls technology and wind tunnel test program at NASA Langley Research Center was started with the objective to investigate the nonlinear, unsteady aerodynamics and active flutter suppression of wings in transonic flow. The paper will present the flutter suppression control law design process, numerical nonlinear simulation and wind tunnel test results for the NACA 0012 ...

Ihese fast, precise, programmable plotters draw report-quality four-color p/ots. Features include dashed-line fonts, several built-in character fonts, user-defined characters, and symbol plotting. F napUIC PEN PLOTTERS provide a permanent, \f graphical representation of collections of numbers. The numbers may be derived from financial and statistical data bases, test and measurement system outp...

Input nonlinearities, or actuator nonlinearities, can be seen in a lot of systems and have significant effects on the system performance. From the controller design point of view, accurate yet simple model of input nonlinearities is essential to compensate their effects and to achieve high level control performance. Unfortunately, most input nonlinearities are neither known nor easy to characte...