scholarly journals MATLAB GUI based Steady State Open-loop and Closed-loop Simulation Tools for Different LLC Converters with All Operation Modes

2021 ◽  
pp. 1-1
Author(s):  
Yuqi Wei ◽  
Zhiqing Wang ◽  
Quanming Luo ◽  
Alan Mantooth
Keyword(s):  
Steady State ◽  
Closed Loop ◽  
Open Loop ◽  
Simulation Tools ◽  
Operation Modes

scholarly journals PI- Controlled PV Fed Fly Back Converter with Enhanced Dynamic Response

2019 ◽  
Vol 8 (2S11) ◽  
pp. 4031-4034
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Rise Time ◽  
Closed Loop ◽  
Input Voltage ◽  
Pi Controller ◽  
Open Loop ◽  
Load Variations ◽  
Simulink Model ◽  
Step Down

Fly back converter is the most popular converter because of its simplicity, low part counts and isolation. It occupies less volume and it saves cost. Fly back converter steps up and step down the voltage with the same polarity. Open loop operation remains insensitive to the input voltage and load variations. Matlab Simulink model for Fly back converter is established using PI controller. Open loop Fly back converter system and closed loop fly back converter systems are simulated and their outcomes are compared. Comparison is done in terms of Rise time ,Settling time and steady state error

Performance Evaluation of a Thermally Integrated Fuel Cell System in the Presence of Uncertainties

2006 ◽  
Author(s):  
Vasilis Tsourapas ◽  
Jing Sun ◽  
Anna Stefanopoulou
Keyword(s):  
Steady State ◽  
Fuel Cell ◽  
Closed Loop ◽  
Robustness Analysis ◽  
Cell System ◽  
Open Loop ◽  
Proton Exchange ◽  
Feedback Controller ◽  
Loop System ◽  
Load Following

In this work, we focus on robustness analysis of an integrated fuel cell and fuel reforming (FCFR) system, which relies on a feedback controller to mitigate hydrogen starvation and temperature overshoot during load transitions. The fuel reformer is used to process natural gas into a hydrogen rich flow to be utilized in a proton exchange membrane fuel cell (PEM-FC). The feedback controller uses the catalytic burner (CB) and the catalytic partial oxidizer (CPOX) temperatures as measurements and adjusts the air and fuel actuator commands to assure fast load following and high steady state efficiency. Several uncertainty sources which can potentially lead to closed loop performance deterioration are considered, including CPOX clogging, hydro-desulphurizer (HDS) clogging, fuel uncertainty and CB parameter uncertainty. Steady state and transient performance are analyzed for the different uncertainty scenarios, for both open and closed loop operation (i.e., with and without feedback control). The robustness of load following and CPOX temperature regulation of the closed loop system (feedforward and feedback controlled) is established, while the open loop system (feedforward controlled) is shown to be vulnerable to all sources of uncertainties considered.

Computer Simulation of a Variable Fill Hydraulic Dynamometer: Part 2: Steady State and Dynamic Open-Loop Performance

1992 ◽  
Vol 206 (1) ◽  
pp. 49-56 ◽  
Author(s):  
P G Hodgson ◽  
J K Raine
Keyword(s):  
Steady State ◽  
Closed Loop ◽  
Open Loop ◽  
Stable Set ◽  
Open Loop Control ◽  
Test Bed ◽  
Loop Control ◽  
Transient Phenomena ◽  
Absorption Performance ◽  
Dissipation Processes

Part 1 of this paper presented a theoretical model for the torque absorption and energy dissipation processes in a variable fill Froude-type hydraulic dynamometer. Effects of working compartment geometry changes on steady state running full torque absorption performance were also shown. Part 2 presents both steady state and dynamic computer simulations of an engine-dynamometer system under open-loop control. Comparisons between model simulations and test bed data show that the dynamic model reproduces both the negative torque-speed dynamometer characteristics and other transient phenomena that occur under real open-loop partial fill conditions. Requirements of control systems to modify this behaviour and ensure stable set point holding are introduced. Part 3 of the paper will deal with the simulation of the engine-dynamometer system under closed-loop control.

Steady-state and transient control strategies for a two-stage turbocharged diesel engine

2017 ◽  
Vol 232 (9) ◽  
pp. 1167-1179 ◽  
Author(s):  
Zhilong Hu ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Xinxin Yang ◽  
Baochuan Zhang
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Closed Loop ◽  
Control Strategies ◽  
Open Loop ◽  
Two Stage ◽  
Loop Control ◽  
Turbocharging System ◽  
Transient Control ◽  
Response Performance

Two-stage turbocharging technology is widely used to achieve higher engine power density and lower exhaust emissions. To solve a series of contradictions in matching, a regulated two-stage (RTS) turbocharging system is applied to reasonably control boost pressure. This paper investigated steady-state and transient control strategies for an RTS turbocharging system to achieve optimum fuel economy in steady-state conditions and better performance in transient conditions. The economic control strategies for steady-state operational conditions were based on an economic regulation law, which was established by a steady-state test of an engine with an RTS turbocharging system under all operating conditions. To optimize the transient performance, open-loop and closed-loop control systems (the latter with dynamic judgement) for the RTS system were designed and validated with experiments on a heavy-duty diesel engine. The experimental results demonstrated that the open-loop control strategy and the closed-loop strategy with dynamic judgement could improve the transient response performance. The optimum transient response performance was achieved by the closed-loop control system with dynamic judgement. Additionally, the combination of steady-state and transient control strategies could achieve the best fuel economy in steady-state conditions and good transient response performances.

scholarly journals Design of Flow Control System with A Kickback Flow as A Manipulated Variable

Eksergi ◽  
2017 ◽  
Vol 14 (2) ◽  
pp. 23
Author(s):  
Yulius Deddy Hermawan
Keyword(s):  
Steady State ◽  
Flow Control ◽  
Liquid Flow ◽  
Stability Criterion ◽  
Closed Loop ◽  
Open Loop ◽  
Loop Model ◽  
Point Change ◽  
Controller Gain ◽  
Control Configuration

The open loop experiment of water flow dynamic in pipe has been done in laboratory. Pump was used to flow water in pipe. Part of liquid from discard of pump was recycled back to the suction of pump (kickback) and adjusted to control the liquid flow to the next process. The open loop laboratory experiment produced the steady state parameters; they were discard flowrate =16.6 [L/min], kickback flowrate =5.8 [L/min], and liquid flowrate to the next process =10.8 [L/min]. These steady state parameters were then used as the initial value for closed loop simulation with computer programming. This study has proposed the liquid flow control configuration by manipulating the kickback flow. Proportional Integral (PI) was proposed to control the flow and Routh-Hurwitz (RH) stability criterion was chosen to predict the range of the controller gain (Kc) that gives stable response. The closed loop model was solved analytically with Laplace method for both servo and regulatory problems. The set point change of flow and disturbance were made based on step function. The scilab software was used to do closed loop simulation. Based on RH stability criterion, the controller gain should be negative in order to give stable response. The closed loop simulation showed that by using controller gain Kc=–0.5 and integral time constant tI=0.3 [min], stable and fast response with Integral Absolute Error (IAE) near to zero (0,0022) could be achieved.

Comparison of PI and PID Controlled Bidirectional DC-DC Converter Systems

2016 ◽  
Vol 7 (1) ◽  
pp. 56 ◽  
Author(s):  
K.C. Ramya ◽  
V. Jegathesan
Keyword(s):  
Steady State ◽  
Case Studies ◽  
Rise Time ◽  
Closed Loop ◽  
High Gain ◽  
Open Loop ◽  
Pid Controllers ◽  
Controlled Systems ◽  
Time Fall ◽  
Made In

<p>This paper deals with comparison of responses of the PI and the PID controlled bidirectional DC-DC converter systems. A coupled inductor is used in the present work to produce high gain. Open loop and closed loop controlled systems with PI and PID controllers are designed and simulated using Matlab tool. The principles of operation and simulation case studies are discussed in detail. The comparison is made in terms of rise time, fall time, peak overshoot and steady state error.</p>

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

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