Full State Feedback Control of Steam Temperature in a Once-Through Direct Steam Generation Receiver Powered by a Paraboloidal Dish

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
José I. Zapata
Keyword(s):  
Mass Flow ◽  
State Feedback ◽  
Water Mass ◽  
Feed Water ◽  
Steam Temperature ◽  
Steam Generation ◽  
Full State ◽  
Direct Steam ◽  
Full State Feedback ◽  
National University

Once-through direct steam generation (DSG) plants convert water into superheated steam suitable for a steam turbine with a single pass of the fluid through the receiver. The control problem in such a plant is to set a feed-water mass flow that maintains a desired steam condition (e.g., temperature) while rejecting the disturbance effect of variable direct normal irradiance (DNI). A mass flow control strategy preserves the simplicity of the plant, but is challenging to implement from a control perspective, as the disturbance effect is nonlinear and difficult to measure, due to the complex physical nature of two-phase flow and the receiver geometry. A model of the receiver behavior can be incorporated into the controller design in the form of a state observer, to estimate the internal behavior of the receiver during operation. This paper presents the design, testing an experimental implementation of full state linear feedback controller for the steam temperature for a once-through DSG system. The system consists of a 500 m2 paraboloidal dish concentrator and a monotube cavity receiver at the Australian National University. The controller manipulates the feed-water mass flow at the receiver inlet to maintain a predetermined specific enthalpy at the receiver outlet, compensating for variations in DNI and other ambient conditions. The controller features three separate regulation mechanisms: a feedforward (FF) law to anticipate changes in DNI; a full state feedback (FSF) loop with a state observer for the receiver; and an additional integrator loop for robustness. Experiments on the Australian National University (ANU) system show that the linear controller maintains steam temperatures to within 3% of a set reference of 500 °C during clear sky conditions, subject to adequate controller tuning. These results show that it is possible to control the ANU system with an FSF loop and state estimator, opening the possibility to test more advanced state based controllers.

Full State Feedback Control of Steam Temperature in a Once-Through Direct Steam Generation Receiver Powered by a Paraboloidal Dish

2014 ◽  
Author(s):  
José I. Zapata
Keyword(s):  
Mass Flow ◽  
State Feedback ◽  
Water Mass ◽  
Feed Water ◽  
Steam Temperature ◽  
Steam Generation ◽  
Linear Controller ◽  
Full State ◽  
Direct Steam ◽  
Full State Feedback

DSG plants in a once-through configuration convert water into superheated steam suitable for a steam turbine, with a single pass of the fluid through the receiver. The control problem is to manipulate the feed-water mass flow to maintain a desired steam condition (e.g. temperature) under variable solar radiation. This paper presents a full state linear feedback controller for the steam temperature for a once-through direct steam generation system, featuring a 500 m2 paraboloidal dish concentrator and a mono-tube cavity receiver at the Australian National University. The controller manipulates the feed-water mass flow at the receiver inlet to maintain a predetermined specific enthalpy at the receiver outlet, compensating for variations in direct normal irradiation (DNI) and other ambient conditions. The linear controller features three separate regulation mechanisms: a feedforward law to anticipate changes in DNI; a full state feedback loop that uses a state observer for the receiver and an additional output feedback integrator loop for robustness. Experimental results show that the linear controller can successfully control the temperature of the SG4 receiver, provided that it is adequately tuned.

Flexible-Joint Humanoid Balancing Augmentation via Full-State Feedback Variable Impedance Control

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Impedance Control ◽  
Humanoid Robots ◽  
Flexible Joint ◽  
Model Free ◽  
Floating Base ◽  
Full State ◽  
Full State Feedback ◽  
Series Elastic Actuators

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.

Active Vehicle Suspension Control Using Full State-Feedback Controller

2015 ◽  
Vol 1115 ◽  
pp. 440-445 ◽  
Author(s):  
Musa Mohammed Bello ◽  
Amir Akramin Shafie ◽  
Raisuddin Khan
Keyword(s):  
State Feedback ◽  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Feedback Controller ◽  
Vehicle Suspension ◽  
Passive Suspension ◽  
Full State ◽  
Full State Feedback ◽  
Passive Suspension System

The main purpose of vehicle suspension system is to isolate the vehicle main body from any road geometrical irregularity in order to improve the passengers ride comfort and to maintain good handling stability. The present work aim at designing a control system for an active suspension system to be applied in today’s automotive industries. The design implementation involves construction of a state space model for quarter car with two degree of freedom and a development of full state-feedback controller. The performance of the active suspension system was assessed by comparing it response with that of the passive suspension system. Simulation using Matlab/Simulink environment shows that, even at resonant frequency the active suspension system produces a good dynamic response and a better ride comfort when compared to the passive suspension system.

Global Balance of Plant in NPPs Using Process Data Reconciliation According to VDI 2048

2014 ◽  
Author(s):  
Magnus Langenstein ◽  
Bernd Laipple
Keyword(s):  
Monitoring System ◽  
Mass Flow ◽  
Online Monitoring ◽  
Water Mass ◽  
Data Reconciliation ◽  
Measurement Information ◽  
Feed Water ◽  
Process Data ◽  
Operation Conditions ◽  
Plant Process

The large quantities of measurement information gathered throughout a plant process make the closing of the mass and energy balance nearly impossible without the help of additional tools. For this reason, a variety of plant monitoring tools for closing plant balances was developed. A major problem with the current tools lies in the non-consideration of redundant measurements which are available throughout the entire plant process. The online monitoring reconciliation system is based on the process data reconciliation according to VDI 2048 standard and is using all redundant measurements within the process to close mass and energy balances. As a result, the most realistic process with the lowest uncertainty can be monitored. This system is installed in more than 35 NPPs worldwide and is used ○ as a basis for correction of feed water mass flow and feed water temperature measurements (recover of lost Megawatts). ○ as a basis for correction of Taverage (Tav) (recover of steam generator outlet pressure in PWRs). ○ for maintaining the thermal core power and the feed water mass flow under continuous operation conditions. ○ for automatic detection of erroneous measurements and measurement drift. ○ for detection of inner leakages, non-condensable gases and system losses. ○ for calculating non measured values (e.g. heat transfer coefficients, ΔT, preheater loads,…). ○ as a monitoring system for the main thermodynamic process. ○ for verifying warranty tests more accurate. ○ as a application of condition-based maintenance and component monitoring. ○ for What-if scenarios (simulation, not PDR) This paper describes the methodology according to VDI 2048 (use of Gaussian correction principle and quality criterias). The benefits gained from the use of the online monitoring system are demonstrated.

Full-State Feedback Tracking Controllers

2000 ◽  
pp. 53-86
Author(s):  
Marcio S. de Queiroz ◽  
Darren M. Dawson ◽  
Siddharth P. Nagarkatti ◽  
Fumin Zhang
Keyword(s):  
State Feedback ◽  
Tracking Controllers ◽  
Full State ◽  
Full State Feedback ◽  
Feedback Tracking
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