scispace - formally typeset

Journal ArticleDOI

Power Quality Enhancement Using Linear Quadratic Regulator Based Current-controlled Voltage Source Inverter for the Grid Integrated Renewable Energy System

02 Oct 2017-Electric Power Components and Systems (Taylor & Francis)-Vol. 45, Iss: 16, pp 1783-1794

TL;DR: An optimal control strategy using linear quadratic regulator applied in current-controlled voltage source inverter (CCVSI) to control the real and reactive power flow between the renewable energy system (RES) and the grid is presented.
Abstract: This paper presents an optimal control strategy using linear quadratic regulator (LQR) applied in current-controlled voltage source inverter (CCVSI) to control the real and reactive power flow betw...
Topics: AC power (60%), Linear-quadratic regulator (59%), Optimal control (53%), Bang–bang control (50%)
Citations
More filters


Journal ArticleDOI
TL;DR: The SMC using equivalent control function outperforms the other methods in terms of chattering, THD and PF in the grid during balanced and unbalanced grid voltage conditions even in the existence of nonlinear loads.
Abstract: Development of control technologies facilitates the integration of renewable energy sources to the grid through power electronic converters. In this study, the inverter acts as shunt active power filter along with the power conversion operation. Various sliding mode control (SMC) techniques namely relay and signum method, hysteresis method and equivalent control method are implemented to control the real, and reactive power flow between Renewable Energy System (RES), load and grid using an inverter. To reduce the complexity, the control law (u eq) for equivalent control method is derived using a simple single-phase equivalent circuit of a three-phase voltage source inverter. In this study, the robustness is enhanced by choosing the integral sliding surface. These controllers are used to reduce the total harmonic distortion (THD) and to ensure unity power factor (PF) in the grid during balanced and unbalanced grid voltage conditions even in the existence of nonlinear loads. The SMC using equivalent control function outperforms the other methods in terms of chattering, THD and PF. To illustrate the effectiveness, three different modes are considered: (i) no RES power, (ii) insufficient RES power and (iii) excess RES power. The performance of controllers is validated by the simulation and experimental results.

5 citations


Journal ArticleDOI
24 Apr 2020-Symmetry
TL;DR: This article constructed Lyapunov-Krasovskii functionals containing several symmetric positive definite matrices to obtain robust finite-time stability and stabilization of the uncertain linear system with a non-differentiable time-varying delay.
Abstract: Practical systems such as hybrid power systems are currently implemented around the world. In order to get the system to work properly, the systems usually require their behavior to be maintained or state values to stay within a certain threshold. However, it is difficult to form a perfect mathematical model for describing behavior of the practical systems since there may be some information (uncertainties) that is not observed. Thus, in this article, we studied the stability of an uncertain linear system with a non-differentiable time-varying delay. We constructed Lyapunov-Krasovskii functionals (LKFs) containing several symmetric positive definite matrices to obtain robust finite-time stability (RFTS) and stabilization (RFTU) of the uncertain linear system. With the controller and uncertainties in the considered system, there exist nonlinear terms occurring in the formulation process. Past research handled these nonlinear terms as new variables but this led to some difficulty from a computation point of view. Instead, we applied a novel approach via Cauchy-like matrix inequalities to handle these difficulties. In the end, we present three numerical simulations to show the effectiveness of our proposed theory.

3 citations


Journal ArticleDOI
TL;DR: This paper presents a control to mitigate these power quality issues in addition to the control of power flow between solar photovoltaic system and non-linear load, using linear quadratic regulator.
Abstract: Due to the growth in population and technology, the demand in energy increases. This motivates us to use renewable energy system, and to interconnect the renewable energy system with the grid. The interconnection of renewable energy system with the grid requires inverters. But these inverters and the commonly used loads like uninterrupted power supplies deteriorate the power quality in the grid. In order to overcome the issues affecting the power quality, a controller is required. This paper presents a control to mitigate these power quality issues in addition to the control of power flow between solar photovoltaic system and non-linear load. Depending on the climatic conditions, the flow of power from the solar photovoltaic system differs. This variation is considered as three modes: zero power generation, less power generation and more power generation. In order to manage these modes along with the power quality improvement, linear quadratic regulator is used in this paper. To validate these modes, the simulation is carried out in MATLAB/SIMULINK environment, and the results are presented.

2 citations



References
More filters

Book
01 Jan 1970-
TL;DR: This comprehensive treatment of the analysis and design of continuous-time control systems provides a gradual development of control theory and shows how to solve all computational problems with MATLAB.
Abstract: From the Publisher: This comprehensive treatment of the analysis and design of continuous-time control systems provides a gradual development of control theory—and shows how to solve all computational problems with MATLAB. It avoids highly mathematical arguments, and features an abundance of examples and worked problems throughout the book. Chapter topics include the Laplace transform; mathematical modeling of mechanical systems, electrical systems, fluid systems, and thermal systems; transient and steady-state-response analyses, root-locus analysis and control systems design by the root-locus method; frequency-response analysis and control systems design by the frequency-response; two-degrees-of-freedom control; state space analysis of control systems and design of control systems in state space.

6,629 citations


Journal ArticleDOI
Abstract: The conventional reactive power in single-phase or three- phase circuits has been defined on the basis of the average value concept for sinusoidal voltage and current waveforms in steady states. The instantaneous reactive power in three-phase circuits is defined on the basis of the instantaneous value concept for arbitrary voltage and current waveforms, including transient states. A new instantaneous reactive power compensator comprising switching devices is proposed which requires practically no energy storage components.

3,182 citations


"Power Quality Enhancement Using Lin..." refers background in this paper

  • ...The instantaneous p–q theory uses the instantaneous values instead of average values [14] and can be controlled in real time [15]....

    [...]


Book
01 Jan 2007-
Abstract: Preface. 1. Introduction. 1.1. Concepts and Evolution of Electric Power Theory. 1.2. Applications of the p-q Theory to Power Electronics Equipment. 1.3. Harmonic Voltages in Power Systems. 1.4. Identified and Unidentified Harmonic-Producing Loads. 1.5. Harmonic Current and Voltage Sources. 1.6. Basic Principles of Harmonic Compensation. 1.7. Basic Principles of Power Flow Control. References. 2. Electric Power Definitions: Background. 2.1. Power Definitions Under Sinusoidal Conditions. 2.2. Voltage and Current Phasors and the Complex Impedance. 2.3. Complex Power and Power Factor. 2.4. Concepts of Power Under Non-Sinusoidal Conditions -Conventional Approaches. 2.5. Electric Power in Three-Phase Systems. 2.6. Summary. References. 3 The Instantaneous Power Theory. 3.1. Basis of the p-q Theory. 3.2. The p-q Theory in Three-Phase, Three-Wire Systems. 3.3. The p-q Theory in Three-Phase, Four-Wire Systems. 3.4. Instantaneous abc Theory. 3.5. Comparisons between the p-q Theory and the abc Theory. 3.6. Summary. References. 4 Shunt Active Filters. 4.1. General Description of Shunt Active Filters. 4.2. Three-Phase, Three-Wire Shunt Active Filters. 4.3. Three-Phase, Four-Wire Shunt Active Filters. 4.4. Shunt Selective Harmonic Compensation. 4.5. Summary. References. 5 Hybrid and Series Active Filters. 5.1. Basic Series Active Filter. 5.2. Combined Series Active Filter and Shunt Passive Filter. 5.3. Series Active Filter Integrated with a Double-Series Diode Rectifier. 5.4. Comparisons Between Hybrid and Pure Active Filters. 5.5. Conclusions. References. 6 Combined Series and Shunt Power Conditioners. 6.1. The Unified Power Flow Controller (UPFC). 6.2. The Unified Power Quality Conditioner (UPQC). 6.3. The Universal Active Power Line Conditioner (UPLC). 6.4. Summary. References. Index.

1,893 citations


"Power Quality Enhancement Using Lin..." refers background in this paper

  • ...The instantaneous p–q theory uses the instantaneous values instead of average values [14] and can be controlled in real time [15]....

    [...]


Journal ArticleDOI
Jose Rodriguez1, J. Pontt1, Cesar Silva1, P. Correa2  +3 moreInstitutions (3)
TL;DR: The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions.
Abstract: This paper presents a predictive current control method and its application to a voltage source inverter. The method uses a discrete-time model of the system to predict the future value of the load current for all possible voltage vectors generated by the inverter. The voltage vector which minimizes a quality function is selected. The quality function used in this work evaluates the current error at the next sampling time. The performance of the proposed predictive control method is compared with hysteresis and pulsewidth modulation control. The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions

1,288 citations


"Power Quality Enhancement Using Lin..." refers background in this paper

  • ...This limits the usage of hysteresis controllers to low power levels [29]....

    [...]

  • ...This may not be preferable for certain applications [29]....

    [...]


Book
31 Aug 2002-
Abstract: Power Quality Enhancement Using Custom Power Devices considers the structure, control and performance of series compensating DVR, the shunt DSTATCOM and the shunt with series UPQC for power quality improvement in electricity distribution. Also addressed are other power electronic devices for improving power quality in Solid State Transfer Switches and Fault Current Limiters. Applications for these technologies as they relate to compensating busses supplied by a weak line and for distributed generation connections in rural networks, are included. In depth treatment of inverters to achieve voltage support, voltage balancing, harmonic suppression and transient suppression in realistic network environments are also covered. New material on the potential for shunt and series compensation which emphasizes the importance of control design has been introduced. Power Quality Enhancement Using Custom Power Devices is appropriate for distribution engineers, graduate engineers and designers working in the area of power electronic applications for power systems. Sections of the book on power quality issues and generation connection make for a timely reference for undergraduates studying distribution engineering. Written for: Distribution engineers, graduate engineers and designers working in the area of power electronic applications for power systems, students

992 citations