A novel control strategy combined by both of energy optimal and time optimal control for voltage sag compensator

2009 ◽  
Author(s):  
Pei Chen ◽  
Zenglu Chen ◽  
Yanfang Li
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Time Optimal Control ◽  
Voltage Sag ◽  
Time Optimal

Discrete Adjoint Sensitivities for the Real-Time Optimal Control of Large District Heating Networks During Failure Events

2016 ◽  
Author(s):  
Alberto Pizzolato ◽  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Optimal Control ◽  
Temperature Field ◽  
Real Time ◽  
Control Strategy ◽  
District Heating ◽  
Time Optimal Control ◽  
The Real ◽  
Discrete Adjoint ◽  
Time Optimal ◽  
Heating Networks

In this paper, we propose an innovative approach for the real-time optimal control of district heating networks during anomalous conditions. We aim at minimizing the maximum thermal discomfort of the connected users after a pipe breakage by an integrated and centralized management of the user control-valves. Our control strategy uses a gradient-based optimizer driven by discrete adjoint sensitivities, which makes it fast and nearly insensitive to the problem dimensions. We tested the proposed approach by simulating a set of different malfunctions in the Turin District heating network and by analyzing the building temperature field during the optimizer convergence history. Compared to the control strategy in use today, we observe that our approach flattens the temperature field and eliminates discomfort peaks, bringing a considerable increase of the minimum user temperature which ranges from a minimum of 1.8 °C to a maximum of 15.4 °C. Furthermore, our optimization strategy allows for superior results to what is achievable conventionally with an 85 % increase of the pumping head, making back-up pumping devices a non-necessary investment.

Multistage Time-Optimal Control for Synchronization Process in Electric-Driven Mechanical Transmission With Angle Alignment Considering Torque Response Process

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Ziwang Lu ◽  
Guangyu Tian ◽  
Simona Onori
Keyword(s):  
Optimal Control ◽  
Control Problem ◽  
Control Strategy ◽  
Time Optimal Control ◽  
Response Process ◽  
Rule Based ◽  
Synchronization Process ◽  
Torque Response ◽  
Time Optimal ◽  
Bang Bang Control

Abstract The synchronization process takes up almost one half of the time of the gear-shifting process, and also influences the impacts between the sleeve and the gear ring. To avoid impacts and reduce time duration, a time-optimal control strategy with angle alignment is necessary for the synchronization process. Moreover, to be better accord with practice, the motor torque response process should be taken into account. The parameters in the torque response process depend on control commands, which makes the control problem a multistage one. To solve these issues, a rule-based control strategy is extracted from the dynamic programming (DP) solution of the multistage time-optimal control problem. To obtain this strategy, the dynamic model for the synchronization process with a modified Sigmoid model to precisely depict the torque response process is first solved. Then, the control problem is formulated as a multistage time-optimal control problem with three states and solved by DP. Based on the DP results, a three-stage and a four-stage rule-based control strategies are extracted for normal operation situation and startup situation, respectively. Finally, through comparative studies, the proposed rule-based control strategy can eliminate the speed difference and angle difference simultaneously with almost the same time of the bang–bang control, while the bang–bang control cannot obtain the zero terminals. Moreover, the proposed control strategy only takes 20 ms more than the pure speed synchronization control in the worst case. It would decrease when the initial speed difference increases.

Observer-based time-optimal control of an aerobic SBR for chemical and petrochemical wastewater treatment

2000 ◽  
Vol 42 (5-6) ◽  
pp. 163-170 ◽  
Author(s):  
A. Vargas ◽  
G. Soto ◽  
J. Moreno ◽  
G. Buitrón
Keyword(s):  
Optimal Control ◽  
Reaction Time ◽  
Control Strategy ◽  
Optimal Operation ◽  
Time Optimal Control ◽  
Nonlinear Observer ◽  
Synthetic Wastewater ◽  
Optimal Control Strategy ◽  
Time Optimal ◽  
High Concentrations

The present study implements a time-optimal control strategy for a discontinuous aerobic bioreactor, used to treat highly concentrated toxic wastewater present in some effluents of the chemical and petrochemical industries, using respirometric techniques. The control strategy regulates the feed rate to maintain a constant optimal substrate concentration in the reactor, which in turn minimizes the reaction time. Since this control requires on-line knowledge of unmeasurable variables, an Extended Kalman Filter is used as a nonlinear observer. The experimental setup was a 7 litre laboratory bioreactor used to treat synthetic wastewater with high concentrations of 4-chlorophenol. The controller consisted of a personal computer with data acquisition hardware and real-time software tools, peristaltic pumps and an electronic oxygen meter. Three experiments were performed: one to obtain parameters and calibrate the observer, another one to validate the time-optimal strategy and a final one to evaluate theperformance of a fully automated time-optimal operation. When well calibrated, the observer provided good enough estimates and the controller worked as expected, reducing reaction time and increasing the overall efficiency of the bioreactor, when compared with the usual SBR-type operation.

Time-Optimal Control of Flexible Robots Made Robust Through Wave-Based Feedback

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
William J. O’Connor ◽  
David J. McKeown
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Robustness Analysis ◽  
Optimal Solution ◽  
Open Loop ◽  
Time Optimal Control ◽  
System Model ◽  
Optimal Control Strategy ◽  
Modeling Errors ◽  
Time Optimal

This paper presents a new, robust, time-optimal control strategy for flexible manipulators controlled by acceleration-limited actuators. The strategy is designed by combining the well-known, open-loop, time-optimal solution with wave-based feedback control. The time-optimal solution is used to design a new launch wave input to the wave-based controller, allowing it to recreate the time-optimal solution when the system model is exactly known. If modeling errors are present or a real actuator is used, the residual vibrations, which would otherwise arise when using the time-optimal solution alone, are quickly suppressed due to the additional robustness provided by the wave-based controller. A proximal time-optimal response is still achieved. A robustness analysis shows that significant improvements can be achieved using wave-based control in conjunction with the time-optimal solution. The implications and limits are also discussed.

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