The Use of a Real-Time Simulator for Analysis of Power Grid Operation States with a Wind Turbine

The main issue in this paper is the real-time simulator of a part of a power grid with a wind turbine. The simulator is constructed on the basis of a classic PC running under a classic operating system. The proposed solution is expected and desired by users who intend to manage power microgrids as separate (but not autonomous) areas of common national power systems. The main reason for the decreased interest in real-time simulators solutions built on the basis of PC is the simulation instability. The instability of the simulation is due to not keeping with accurate results when using small integration steps and loss of accuracy or loss of stability when using large integration steps. The second obstacle was due to the lack of a method for integrating differential equations, which gives accurate results with a large integration step. This is the scientific problem that is solved in this paper. A new solution is the use of a new method for integrating differential equations based on average voltage in the integration step (AVIS). This paper shows that the applied AVIS method, compared to other methods proposed in the literature (in the context of real-time simulators), allows to maintain simulation stability and accurate results with the use of large integration steps. A new (in the context of the application of the AVIS method) mathematical model of a power transformer is described in detail, taking into account the nonlinearity of the magnetization characteristics. This model, together with the new doubly-fed induction machine model (described in the authors’ previous article), was implemented in PC-based hardware. In this paper, we present the results of research on the operation states of such a developed real-time simulator over a long period (one week). In this way, the effectiveness of the operation of the real-time simulator proposed in the paper was proved.

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Power Hardware-in-the-Loop: Response of Power Components in Real-Time Grid Simulation Environment

Energies ◽

10.3390/en14030593 ◽

2021 ◽

Vol 14 (3) ◽

pp. 593

Author(s):

Moiz Muhammad ◽

Holger Behrends ◽

Stefan Geißendörfer ◽

Karsten von Maydell ◽

Carsten Agert

Keyword(s):

Real Time ◽

Power Distribution ◽

Control Strategies ◽

Power Grid ◽

Energy System ◽

Hardware In The Loop ◽

Distribution Grid ◽

Compensation Strategy ◽

Software Environment ◽

The Real

With increasing changes in the contemporary energy system, it becomes essential to test the autonomous control strategies for distributed energy resources in a controlled environment to investigate power grid stability. Power hardware-in-the-loop (PHIL) concept is an efficient approach for such evaluations in which a virtually simulated power grid is interfaced to a real hardware device. This strongly coupled software-hardware system introduces obstacles that need attention for smooth operation of the laboratory setup to validate robust control algorithms for decentralized grids. This paper presents a novel methodology and its implementation to develop a test-bench for a real-time PHIL simulation of a typical power distribution grid to study the dynamic behavior of the real power components in connection with the simulated grid. The application of hybrid simulation in a single software environment is realized to model the power grid which obviates the need to simulate the complete grid with a lower discretized sample-time. As an outcome, an environment is established interconnecting the virtual model to the real-world devices. The inaccuracies linked to the power components are examined at length and consequently a suitable compensation strategy is devised to improve the performance of the hardware under test (HUT). Finally, the compensation strategy is also validated through a simulation scenario.

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Discrete Wavelet Transform for the Real-Time Smoothing of Wind Turbine Power Using Li-Ion Batteries

Energies ◽

10.3390/en14082184 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2184

Author(s):

Andrea Mannelli ◽

Francesco Papi ◽

George Pechlivanoglou ◽

Giovanni Ferrara ◽

Alessandro Bianchini

Keyword(s):

Wavelet Transform ◽

Wind Turbine ◽

Discrete Wavelet Transform ◽

Real Time ◽

Power Output ◽

Discrete Wavelet ◽

Smoothing Technique ◽

The Real ◽

Power Smoothing ◽

Li Ion

Energy Storage Systems (EES) are key to further increase the penetration in energy grids of intermittent renewable energy sources, such as wind, by smoothing out power fluctuations. In order this to be economically feasible; however, the ESS need to be sized correctly and managed efficiently. In the study, the use of discrete wavelet transform (Daubechies Db4) to decompose the power output of utility-scale wind turbines into high and low-frequency components, with the objective of smoothing wind turbine power output, is discussed and applied to four-year Supervisory Control And Data Acquisition (SCADA) real data from multi-MW, on-shore wind turbines provided by the industrial partner. Two main research requests were tackled: first, the effectiveness of the discrete wavelet transform for the correct sizing and management of the battery (Li-Ion type) storage was assessed in comparison to more traditional approaches such as a simple moving average and a direct use of the battery in response to excessive power fluctuations. The performance of different storage designs was compared, in terms of abatement of ramp rate violations, depending on the power smoothing technique applied. Results show that the wavelet transform leads to a more efficient battery use, characterized by lower variation of the averaged state-of-charge, and in turn to the need for a lower battery capacity, which can be translated into a cost reduction (up to −28%). The second research objective was to prove that the wavelet-based power smoothing technique has superior performance for the real-time control of a wind park. To this end, a simple procedure is proposed to generate a suitable moving window centered on the actual sample in which the wavelet transform can be applied. The power-smoothing performance of the method was tested on the same time series data, showing again that the discrete wavelet transform represents a superior solution in comparison to conventional approaches.

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Advanced Induction Machine model in Phase Coordinates for Wind Turbine Application

2007 IEEE International Electric Machines & Drives Conference ◽

10.1109/iemdc.2007.383599 ◽

2007 ◽

Author(s):

L.A. Fajardo R. ◽

F. Iov ◽

F. Blaabjerg ◽

A. D. Hansen

Keyword(s):

Wind Turbine ◽

Induction Machine ◽

Machine Model ◽

Phase Coordinates

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Applications of Distributed Parallel Real Time Database on Power Grid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.816-817.488 ◽

2013 ◽

Vol 816-817 ◽

pp. 488-492

Author(s):

Li Xin Li ◽

Wei Zhou ◽

Qi Qiang Sun ◽

Jiao Dai ◽

Ji Zhong Han ◽

...

Keyword(s):

Data Management ◽

Real Time ◽

Management System ◽

Power Grid ◽

Database Design ◽

Experimental Results ◽

Data Management System ◽

Meta Data ◽

The Real ◽

Real Time Database

In order to make the real time database more suitable for the computing features, this article points to the distributed and parallel real time database design and architecture. First, a mapping table from table file to machine nodes is established, and then can use meta-data management system to store and manage the mapping table to meet the characteristics of high concurrent access. The whole network computation can access the unified interface provided by the real-time database, retrive data from each node, then collect the data. Experimental results show that this study and the systems designed can meet the computing requirements of a unified whole network.

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Modeling of Uncertainty for the Real-Time Management of Power Systems

Online Optimization of Large Scale Systems ◽

10.1007/978-3-662-04331-8_31 ◽

2001 ◽

pp. 623-647 ◽

Cited By ~ 4

Author(s):

Nicole Gröwe-Kuska ◽

Matthias P. Nowak ◽

Isabel Wegner

Keyword(s):

Power Systems ◽

Real Time ◽

Time Management ◽

The Real

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Optimization of the real-time dispatch with constraints for secure operation of bulk power systems

IEEE Transactions on Power Apparatus and Systems ◽

10.1109/t-pas.1977.32388 ◽

1977 ◽

Vol 96 (3) ◽

pp. 741-757 ◽

Cited By ~ 19

Author(s):

W.R. Barcelo ◽

W.W. Lemmon ◽

H.R. Koen

Keyword(s):

Power Systems ◽

Real Time ◽

The Real ◽

Bulk Power

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Simplification of Mathematical Model of Double Fed Asynchronous Machine

European Journal of Electrical Engineering and Computer Science ◽

10.24018/ejece.2017.1.3.11 ◽

2017 ◽

Vol 1 (3) ◽

Author(s):

Rauf Ismail Mustafayev ◽

Laman Hasan Hasanova

Keyword(s):

Mathematical Model ◽

Differential Equations ◽

Power Systems ◽

Voltage Drop ◽

Renewable Energy Sources ◽

Induction Machine ◽

Sharp Change ◽

Small Hydropower ◽

Algebraic Differential Equations ◽

Rotor Winding

Double Fed Asynchronous Machines in (DFAM) recent years have found wide application both as generators mainly in renewable energy sources (wind power, small hydropower), and as a motors embedded in various electric drives. In order to study the static and dynamic modes of operation of these machines as one of the most effective methods - the method of mathematical modeling is widely used. It was found that the algebraic-differential equations that make up the mathematical model of double fed induction machine are expediently represented in the d and q axes rotating with the rotor speed of the machine. Particularly this form allows relatively simple reproduction of control coordinates - amplitude and frequency converted to the rotor winding voltage. This mathematical model is based on the well-known Park equations for synchronous machines. It is proposed to simplify the algebraic-differential equations of the double-fed induction machine by reducing the transformer emf, the slip emf and the voltage drop on the stator winding of the machine. The results of calculations for the complete equations of the machine having the 6th order and on the simplified equations having the 4th order showed that the error in determining the regime parameters of the machine in steady-state conditions is in the range 0-7%, i.e. does not exceed 7 percent. The error in dynamic modes is also within acceptable limits. In the dynamics of the change in the regime parameters of DFIM with a sharp change in the disturbing influences slightly differ from each other, and with a sharp change in the control actions they make up 20-30%. This allows to recommend the proposed simplification for engineering calculations, especially when these machines operate in a group or in parallel with other machines and components of power systems.

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