Quasi-Z-Source Inverters in Renewable Power Systems Modeling

This paper is devoted to in-detail demonstrationand description of the overall functionality and deailed processes in every component of quasi-z-source voltage inverter. Expressions for currents and voltages on all elements of the circuit in standard and "shoot-trough" modes are provided. These ratios demonstrate one of the main technological advantages of the quasi-z-source topology: which is the possibility of the voltage reduction on one of the capacitor that forms the quasi-z-circuitry that led to the overall size and weight reduction of the resulting device and additional reliability increase. Matlab calculations,that are provided in the practical part of the article,fully confirmed the theoretical dependencies. At the same time, obtained practical results of the simulation demonstrated the main advantage of the quasi-impedance topology - the ability to provide a continuous current of the input source without zero pauses. That is additionally confirmed by a graphical representation of transients and the spectrum of the output voltage of the inverter. As the second topic of the article, the problem of the control system operating principle selection was discussed. As it was determined in the process of the previous research and practical modeling of the quasi-z-source inverter, providing a switching of the inverter valves on the frequency that equal to the frequency of the desired output voltage, which for the most of the world’s electrical power systems is equal to 50-60 Hz, is leading to a size and mass increase of the quasi-z-source circuitry, according to its design ratios. Additionally, such component are either not represented in the modern electronic components lineup or providing sufficient energy losses that in some design cases could neglect the voltage boost effect of the quasi-z-source circuitry implementation. To overcome discovered limitations, several PWM control methods were suggested. All of them could be divided into two groups: classic and vector PWM methods. Classic methods are based on combination of the basic PWM modulation techniques that are widely used in conventional full-bridge invertors with the insertion of the “shoot-trough” state activation mode. A model of the control system for the classical approach is offered. It is shown that the method of simple control of the state of "breakdown" is based on the placement of time intervals of the inverter in the state of "breakdown" within the normal period of operation of the bridge inverter. The only difference between the models is the inclusion of an additional constant signal exceeding the amplitude of which the carrier leads to the activation of the “shoot-trough” state.In conclusion the discussion on topic of the classic control methods implementation in up-to-date designs and possibility of its combination with a different modern approaches aimed on a quasi-z-source topology parameters modification are provided.

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An advanced control system for the optimal operation and management of medium size power systems with a large penetration from renewable power sources

Renewable Energy ◽

10.1016/s0960-1481(97)00028-1 ◽

1997 ◽

Vol 12 (2) ◽

pp. 137-149 ◽

Cited By ~ 11

Author(s):

E. Nogaret ◽

G. Stavrakakis ◽

G. Kariniotakis ◽

M. Papadopoulos ◽

N. Hatziargyriou ◽

...

Keyword(s):

Control System ◽

Power Systems ◽

Optimal Operation ◽

Medium Size ◽

Power Sources ◽

Renewable Power ◽

Advanced Control ◽

Operation And Management

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A Decentralized Information Filter for the State Estimation in Electrical Power Systems

2007 IEEE Instrumentation & Measurement Technology Conference IMTC 2007 ◽

10.1109/imtc.2007.379111 ◽

2007 ◽

Cited By ~ 2

Author(s):

Gabriele D'Antona ◽

Antonello Monti ◽

Ferdinanda Ponci

Keyword(s):

Power Systems ◽

State Estimation ◽

Electrical Power ◽

The State ◽

Electrical Power Systems ◽

Information Filter

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Ancillary Service Requirements Assessment Indices with the LFC in a Restructured Power Systems for RFB Unit by using Bacterial Foraging Optimization

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a1931.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 1110-1120

Keyword(s):

Control System ◽

Power Systems ◽

Associate Degree ◽

Electrical Power ◽

Support Service ◽

Ancillary Service ◽

Bacterial Foraging Optimization ◽

Service Demand ◽

Calculation Methodology ◽

Frequency Management

This paper proposes the calculation methodology to leverage the System Support Service Request Valuation Indices (PSASRAI) facility of thetwo _Area Thermal Heat Intersected Power Network (TATRIPS) to highly restored environments. Both Indices display in the supporting demand of the Facility to improve the efficacy of the facility framework's physical activity. In the associated degree interconnected control system, the associated degree sudden strain hassle in any area triggers the frequency variance of the considerable variety of territories and in addition within the tie _line forces. To ensure nice quality, this should be updated to confirm age &circulation of electrical power organizations.In addition to Integral (PI) sort controllers, there are broad uses in the dominant problems of Load Frequency Management (LFC). Consequently, the establishment of the PI management benefits for the restored control system is obtained using the calculation of microorganism hunt optimization (BFO). These regulatorsareexistent to accomplish a quicker reclamation periodwithinyield reactions of the framework. Conjointly vitality reposition is associate degree seductiveoption to embrace within the interest facet administration execution, thereforechemical reaction Flow Batteries (RFB) unit isprofitablywont to satisfy the headwould like and upgraded power gridsupportive Service demand Assessment Indices

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The Extended Kalman Filter in the Dynamic State Estimation of Electrical Power Systems

Enfoque UTE ◽

10.29019/enfoqueute.v9n4.407 ◽

2018 ◽

Vol 9 (4) ◽

pp. 120-130

Author(s):

Holger Ignacio Cevallos Ulloa ◽

Gabriel Intriago ◽

Douglas Plaza ◽

Roger Idrovo

Keyword(s):

Kalman Filter ◽

Power Systems ◽

State Estimation ◽

Extended Kalman Filter ◽

Electrical Power ◽

The State ◽

Dynamic State ◽

State Variables ◽

Electrical Power Systems ◽

Error Index

The state estimation and the analysis of load flow are very important subjects in the analysis and management of Electrical Power Systems (EPS). This article describes the state estimation in EPS using the Extended Kalman Filter (EKF) and the method of Holt to linearize the process model and then calculates a performance error index as indicators of its accuracy. Besides, this error index can be used as a reference for further comparison between methodologies for state estimation in EPS such as the Unscented Kalman Filter, the Ensemble Kalman Filter, Monte Carlo methods, and others. Results of error indices obtained in the simulation process agree with the order of magnitude expected and the behavior of the filter is appropriate due to follows adequately the true value of the state variables. The simulation was done using Matlab and the electrical system used corresponds to the IEEE 14 and 30 bus test case systems. State Variables to consider in this study are the voltage and angle magnitudes.

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Highly Robust Observer Sliding Mode Based Frequency Control for Multi Area Power Systems with Renewable Power Plants

Electronics ◽

10.3390/electronics10030274 ◽

2021 ◽

Vol 10 (3) ◽

pp. 274 ◽

Cited By ~ 1

Author(s):

Van Van Huynh ◽

Bui Le Ngoc Minh ◽

Emmanuel Nduka Amaefule ◽

Anh-Tuan Tran ◽

Phong Thanh Tran

Keyword(s):

Power Systems ◽

Power Plants ◽

Sliding Mode ◽

Frequency Control ◽

The State ◽

Experimental Simulation ◽

Modern State ◽

Robust Observer ◽

Renewable Power ◽

Interconnected Power Systems

This paper centers on the design of highly robust observer sliding mode (HROSM)-based load frequency and tie-power control to compensate for primary frequency control of multi-area interconnected power systems integrated with renewable power generation. At first, the power system with external disturbance is model in the state space form. Then the state observer is used to estimate the system states which are difficult or expensive to measure. Secondly, the sliding mode control (SMC) is designed with a new single phase sliding surface (SPSS). In addition, the whole system asymptotic stability is proven with Lyapunov stability theory based on the linear matrix inequality (LMI) technique. The new SPSS without reaching time guarantees rapid convergence of high transient frequency, tie-power change as well as reduces chattering without loss of accuracies. Therefore, the superiority of modern state-of-the-art SMC-based frequency controllers relies on good practical application. The experimental simulation results on large interconnected power systems show good performance and high robustness against external disturbances when compared with some modern state of art controllers in terms of overshoots and settling time.

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INCREASING AN ACCURACY OF CONTROL ACTION VOLUME CALCULATION IN CENTRALIZED EMERGENCY CONTROL SYSTEM FOR STATE ESTIMATION OF POWER SYSTEMS

Vestnik Chuvashskogo universiteta ◽

10.47026/1810-1909-2021-3-5-20 ◽

2021 ◽

pp. 5-20

Author(s):

Natalia L. Batseva ◽

Julia A. Foos

Keyword(s):

Control System ◽

Power Systems ◽

State Estimation ◽

Static Stability ◽

The State ◽

Control Action ◽

Software Module ◽

Volume Calculation ◽

Emergency Control ◽

Control Actions

The paper presents the results of the study on the effectiveness and advisability of voltage’s and current’s angles usage, collected from a wide-area monitoring system, to increase an accuracy of control actions volume calculation in case of power system’s state estimation. Centralized emergency control system architecture of a power pool system is shown to better understand the research core. We emphasize that the state estimation software module is the key module in a high level hardware and software package. Ways of telemetry and synchronized phasor measurements collection are outlined. For research practice, Gauss-Newton mathematical method is modified via measurement vector, vector-function, and scalar matrix of weight coefficients. Experiments are provided by IEEE 14-bus power system and 500–220 kV real backbone network. These power systems have several control areas, connected by interchanges. According to experiment results, we conclude that using not only voltage’s and current’s modules but also angles increases an accuracy of control actions volume calculation and effectiveness of a centralized emergency control system operation in the part of a control action formation. Therewith, the usage of current’s modules and angles raises the execution time of the state estimation software module. It is undesirable for real time systems operation. Therefore, it is reasonable to take into account current’s modules and angles only for those interchanges in emergency mode, when intensity factor, characterizing the limit of static stability, is more than 0.92. We also find out that control action volume calculation is sensitive to mistakes in current’s angles measurements. Thus, for reliable usage of current’s modules and angles as data for a state estimation and control action volume calculation, it is necessary to prevent timing errors of synchronized phasor measurement units and also develop a phase shift correction algorithm.

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Overview on Grid-Forming Inverter Control Methods

Energies ◽

10.3390/en13102589 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2589 ◽

Cited By ~ 6

Author(s):

Peter Unruh ◽

Maria Nuschke ◽

Philipp Strauß ◽

Friedrich Welck

Keyword(s):

Power Generation ◽

Power Systems ◽

Electrical Power Generation ◽

Power Supply ◽

Electrical Power ◽

Synchronous Machines ◽

Control Methods ◽

Rotating Machines ◽

The Past ◽

Interconnected Power Systems

In this paper, different control approaches for grid-forming inverters are discussed and compared with the grid-forming properties of synchronous machines. Grid-forming inverters are able to operate AC grids with or without rotating machines. In the past, they have been successfully deployed in inverter dominated island grids or in uninterruptable power supply (UPS) systems. It is expected that with increasing shares of inverter-based electrical power generation, grid-forming inverters will also become relevant for interconnected power systems. In contrast to conventional current-controlled inverters, grid-forming inverters do not immediately follow the grid voltage. They form voltage phasors that have an inertial behavior. In consequence, they can inherently deliver momentary reserve and increase power grid resilience.

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