A Full State-Variable Direct Predictive Control for Islanded Microgrids with Parallel Converters

2020 ◽  
pp. 1-1
Author(s):  
Yu Li ◽  
Zhenbin Zhang ◽  
Cungang Hu ◽  
Mohamed Abdelrahem ◽  
Ralph Kennel ◽  
...  
Keyword(s):  
Predictive Control ◽  
State Variable ◽  
Full State ◽  
Parallel Converters

Positioning and Active Damping of Spring-Mass Systems

1989 ◽  
Vol 111 (4) ◽  
pp. 592-599 ◽  
Author(s):  
T. L. Vincent ◽  
S. P. Joshi ◽  
Yeong Ching Lin
Keyword(s):  
Optimal Control Theory ◽  
Closed Loop ◽  
Open Loop ◽  
Closed Loop Control ◽  
Energy Methods ◽  
Loop Control ◽  
State Variable ◽  
Feedback Design ◽  
Full State ◽  
Control Saturation

In this paper, we investigate an alternate approach to the design of controllers for positioning and damping of a system which can be reduced to an equivalent system of springs and masses. The approach taken is to design a controller which uses open-loop positioning followed by closed-loop control for damping. By so doing, we can avoid a conflicting requirements problem associated with traditional state variable feedback design. The open-loop portion of the control is based on optimal control theory, which allows for control saturation. In particular, during this phase of the control, the time to position is minimized. This results in a bang-bang type of control. Once the system has been “positioned,” the controller switches to a closed-loop phase. The particular closed-loop control used here is based on energy methods and is not a full state variable feedback design. The method is illustrated using a low-order spring-mass example, and the results are compared with an LQ design.

Theory and Application of the Lang-Gilles Observer for Distillation Processes

2016 ◽  
Author(s):  
Maxim Stuckert
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Distillation Column ◽  
Simulation Studies ◽  
Multicomponent Mixtures ◽  
Plant Model ◽  
Model Mismatch ◽  
Tray Efficiency ◽  
Full State ◽  
On Line

This thesis deals with the nonlinear full state observer for distillation processes first introduced by Lang and Gilles in 1990. The observer is very attractive in practice as it requires only few temperature measurements in each section of a distillation column and only few observer parameters need to be tuned. We provide conditions under which this observer converges and derive a simple rule for the tuning of the observer parameters. We also give a method for the on-line estimation of the Murphree tray efficiency. Such on-line methods are rarely found in ­literature. In a sequence of simulation studies, we investigate the capabilities of the observer for the estimation of the tray efficiency and for model-predictive control. The simulation studies are based on distillation processes for separation of multicomponent mixtures and one of the studies introduces a plant-model mismatch. ...

scholarly journals Designing optimal speed control with observer using integrated battery-electric vehicle (IBEV) model for energy efficiency

2018 ◽  
Vol 9 (2) ◽  
pp. 89 ◽  
Author(s):  
Rina Ristiana ◽  
Arief Syaichu Rohman ◽  
Estiko Rijanto ◽  
Agus Purwadi ◽  
Egi Hidayat ◽  
...  
Keyword(s):  
Output Feedback ◽  
State Feedback ◽  
Flat Surface ◽  
Speed Control ◽  
State Of Charge ◽  
Battery Electric Vehicle ◽  
State Variable ◽  
Full State ◽  
Full State Feedback ◽  
Battery State Of Charge

This paper develops an optimal speed control using a linear quadratic integral (LQI) control standard with/without an observer in the system based on an integrated battery-electric vehicle (IBEV) model. The IBEV model includes the dynamics of the electric motor, longitudinal vehicle, inverter, and battery. The IBEV model has one state variable of indirectly measured and unobservable, but the system is detectable. The objectives of this study were: (a) to create a speed control that gets the exact solution for a system with one indirect measurement and unobservable state variable; and (b) to create a speed control that has the potential to make a more efficient energy system. A full state feedback LQI controller without an observer is used as a benchmark. Two output feedback LQI controllers are designed; including one controller uses an order-4 observer and the other uses an order-5 observer. The order-4 observer does not include the battery state of charge as an observer state whereas the order-5 observer is designed by making all the state variable as the observer state and using the battery state of charge as an additional system output. An electric passenger minibus for public transport with 1500 kg weight was used as the vehicle model. Simulations were performed when the vehicle moves in a flat surface with the increased speed from stationary to 60 km/h and moves according to standard NEDC driving profile. The simulation results showed that both the output feedback LQI controllers provided similar speed performance as compared to the full state feedback LQI controller. However, the output feedback LQI controller with the order-5 observer consumed less energy than with the order-4 observer, which is about 10% for NEDC driving profile and 12% for a flat surface. It can be concluded that the LQI controller with order-5 observer gives better energy efficiency than the LQI controller with order-4 observer

Integrated predictive control and fault diagnosis algorithm for single inductor-based DC-DC converters for photovoltaic systems

Circuit World ◽  
2020 ◽  
Vol 47 (1) ◽  
pp. 105-116
Author(s):  
Venkateswaran M. ◽  
Govindaraju C. ◽  
Santhosh T.K.
Keyword(s):  
Fault Diagnosis ◽  
Predictive Control ◽  
Continuous Operation ◽  
Control Algorithms ◽  
Solar Pv ◽  
Content Type ◽  
Pv Systems ◽  
State Variable ◽  
Diagnosis Algorithm ◽  
Fault Diagnostic

Purpose Power converters are an integral part of the energy conversion process in solar photovoltaic (PV) systems which is used to match the solar PV generation with the load requirements. The increased penetration of renewable invokes intermittency in the generated power affecting the reliability and continuous energy supply of such converters. DC-DC converters deployed in solar PV systems impose stringent restrictions on supplied power, continuous operation and fault prediction scenarios by continuously observing state variables to ensure continuous operation of the converter. Design/methodology/approach A converter deployed for a mission-critical application has to ensure continuous regulated output for which the converter has to ensure fault-free operation. The fault diagnostic algorithm relies on the measurement of a state variable to assess the type of fault. In the same line, a predictive controller depends on the measurement of a state variable to predict the control variable of a converter system to regulate the converter output around a fixed or a variable reference. Consequently, both the fault diagnosis and the predictive control algorithms depend on the measurement of a state variable. Once measured, the available data can be used for both algorithms interchangeably. Findings The objective of this work is to integrate the fault diagnostic and the predictive control algorithms while sharing the measurement requirements of both these control algorithms. The integrated algorithms thus proposed could be applied to any converter with a single inductor in its energy buffer stage. Originality/value laboratory prototype is created to verify the feasibility of the integrated predictive control and fault diagnosis algorithm. As the proposed method combine the fault detection algorithm along with predictive control, a load step variation and manual fault creation methods are used to verify the feasibility of the converter as with the simulation analysis. The value for the capacitors and inductors were chosen based on the charge-second and volt-second balance equations obtained from the steady-state analysis of boost converter.

scholarly journals Design of Damping and Control Matrices by Modification of Eigenvalues and Eigenvectors

1994 ◽  
Vol 1 (4) ◽  
pp. 317-329 ◽  
Author(s):  
Vernon H. Neubert
Keyword(s):  
State Space ◽  
Direct Methods ◽  
Mode Shapes ◽  
Eigenvalues And Eigenvectors ◽  
State Variable ◽  
Displacement Mode ◽  
Full State ◽  
Unique Method ◽  
Nonproportional Damping ◽  
And Control

Direct methods are presented, in state space, for design of control matrices for structures with and without initial viscous damping. given the desired changes in the eigenvalues and eigenvectors. The equations with full-state variable feedback areMz¨+Cz˙+Kz=−Gz˙−Hz. Advantage is taken of the special state-space form of the structural plant and eigenvector matrices to develop efficient numerical procedures. Essential relationships are derived between the upper and lower portions of the left and right eigenvector matrices for systems with simple eigenvalues. We distinguish between displacement mode shapes and eigenvectors in state space. A unique method is presented by which the[C+G]matrices are designed to achieve specified real parts of the eigenvalues, with no change in mode shapes or eigenvectors. In addition, two general methods are discussed. suitable for systems with nonproportional damping, where the eigenvalues are specified with or without change in mode shapes.

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