Advanced Testing Chain Supporting the Validation of Smart Grid Systems and Technologies

New testing and development procedures and methods are needed to address topics like power system stability, operation and control in the context of grid integration of rapidly developing smart grid technologies. In this context, individual testing of units and components has to be reconsidered and appropriate testing procedures and methods need to be described and implemented. This paper addresses these needs by proposing a holistic and enhanced testing methodology that integrates simulation/software- and hardware-based testing infrastructure. This approach presents the advantage of a testing environment, which is very close to f i eld testing, includes the grid dynamic behavior feedback and is risks-free for the power system, for the equipment under test and for the personnel executing the tests. Furthermore, this paper gives an overview of successful implementation of the proposed testing approach within different testing infrastructure available at the premises of different research institutes in Europe.Comment: 2018 IEEE Workshop on Complexity in Engineering (COMPENG

Solar photovoltaic‑based microgrid hosting capacity evaluation in electrical energy distribution network with voltage quality analysis

Part of a collection: Engineering: Integrated Sustainable Electrical Energy Systems, SN Applied Sciences volume 3, Article number: 567 (2021). Abstract: In this paper, solar photovoltaic hosting capacity within the electrical distribution network is estimated for different buses, and the impacts of high PV penetration are evaluated using power hardware-in-loop testing methods. It is observed that the considered operational constraints (i.e. voltage and loadings) and their operational limits have a significant impact on the hosting capacity results. However, with increasing photovoltaic penetration, some of the network buses reach maximum hosting capacity, which affects the network operation (e.g. bus voltages, line loading). The results show that even distributing the maximum hosting capacity among different buses can increase the bus voltage rise to 9%. To maintain the network bus voltages within acceptable limits, reactive power voltage-based droop control is implemented in the photovoltaic conditioning devices to test the dynamics of the network operation. The results show that implementation of the droop control technique can reduce the maximum voltage rise from 9% to 4% in the considered case. This paper also presents the impact of forming a mesh type network (i.e. from radial network) on the voltage profile during PV penetration, and a comparative analysis of the operational performance of a mesh type and radial type electrical network is performed. It is observed that the cumulative effect of forming a mesh type network along with a droop control strategy can further improve the voltage profile and contribute to increase photovoltaic penetration. The results are verified using an experimental setup of digital real-time simulator and power hardware-in-loop test methods. The results from this work will be useful for estimating the appropriate photovoltaic hosting capacity within a distribution network and implementation of a droop control strategy in power conditioning devices to maintain the network operational parameters within the specified limits.publishedVersio

Comparison of multiple power amplification types for power hardware-in-the-loop applications

This Paper discusses Power Hardware-in-the-Loop simulations from an important point of view: an intrinsic and integral part of PHIL simulation – the power amplification. In various publications PHIL is discussed either in a very theoretical approach or it is briefly featured as the used method. In neither of these publication types the impact of the power amplification to the total PHIL simulation is discussed deeply. This paper extends this discussion into the comparison of three different power amplification units and their usability for PHIL simulations. Finally in the conclusion it is discussed which type of power amplification is best for which type of PHIL experiment

European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0

The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with specifi c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of specifi cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and specifi c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag

Asynchronous Integration of Real-Time Simulators for HIL-based Validation of Smart Grids

As the landscape of devices that interact with the electrical grid expands, also the complexity of the scenarios that arise from these interactions increases. Validation methods and tools are typically domain specific and are designed to approach mainly component level testing. For this kind of applications, software and hardware-in-the-loop based simulations as well as lab experiments are all tools that allow testing with different degrees of accuracy at various stages in the development life-cycle. However, things are vastly different when analysing the tools and the methodology available for performing system-level validation. Until now there are no available well-defined approaches for testing complex use cases involving components from different domains. Smart grid applications would typically include a relatively large number of physical devices, software components, as well as communication technology, all working hand in hand. This paper explores the possibilities that are opened in terms of testing by the integration of a real-time simulator into co-simulation environments. Three practical implementations of such systems together with performance metrics are discussed. Two control-related examples are selected in order to show the capabilities of the proposed approach.Comment: IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Societ

Power hardware in the loop and ancillary service for voltage regulation in low voltage grid

Power production via traditional generators play a major role to meet demand, however, the trend is shifting towards utilization of distributed renewable sources. Distributed Energy Resources (DER) becomes a means to support loads locally. As DERs are typically intermittent sources, there are challenges associated with the high level of penetration of these resources that are of concern to grid operators. There are also opportunities associated with this technology as the inverters connecting the DERs could support voltage regulation by performing reactive power compensation in the grid.The concept of utilizing droop controlled DERs as reactive power resources is explored in this paper. As the active power production fluctuates with solar insolation, the spare capacity of the inverters could be employed to provide effective reactive power compensation to support the grid.In this paper, Power Hardware in the Loop (PHIL) simulation was employed where a single-phase PV inverter hardware is operated in parallel with three other real-time simulated inverters to deliver ancillary services. The results have shown that the switching steps of the On-Load Tap changer transformer (OLTC) were reduced, thus improving overall system performance

Dynamics of inverter droop control and OLTC using power hardware in the loop (PHIL) - (ancillary services supply in low voltage grid)

Distributed Energy Resources (DER) sources installed closer to end users serve as local distributed generators, but they are regarded intermittent sources that pose a challenge to grid operators. Moreover, an increase in penetration of DER into the grid network has created problems related to power quality issues such as voltage sags and swells. The obligation of the grid operators to address power quality issues and energy demand has created an opportunity in the energy market due to the need for ancillary services. In resolving these power quality issues, the coupling DER-inverter becomes an effective tool in supplying ancillary services to the grid. This paper explores the dynamic functionality of a modelled droop-controlled inverter against the conventional OLTC transformers in a Low Voltage grid. The experiment is designed using the Power Hardware in the Loop (PHIL) test setup which combined a hardware DER-inverter, to a simulated low voltage AC distribution network. The test results show that inverter based DERs could enhance ancillary service provision at the distribution level by supporting the operation of the existing OLTC in realizing voltage control

On Modeling Depths of Power Electronic Circuits for Real-Time Simulation – A Comparative Analysis for Power Systems

Investigations of the dynamic behaviour of power electronic components integrated into electric networks require suitable and established simulation methodologies. Real-time simulation represents a frequently applied methodology for analyzing the steady-state and transient behavior of electric power systems. This work introduces a guideline on how to model power electronics converters in digital real time simulators, taking into account the trade-off between model accuracy and the required computation time. Based on this concept, possible execution approaches with respect to the usage of central processing unit and field-programmable gate array components are highlighted. Simulation test scenario, such as primary frequency regulation and low voltage ride through, have been performed and accuracy indices are discussed for each implemented real-time model and each test scenario, respectively. Finally, a run-time analysis of presented real-time setups is given and real-time simulation results are compared. This manuscript demonstrates important differences in real-time simulation modelling, providing useful guidelines for the decision making of power engineers

On Modeling Depths of Power Electronic Circuits for Real-Time Simulation – A Comparative Analysis for Power Systems

Investigations of the dynamic behaviour of power electronic components integrated into electric networks require suitable and established simulation methodologies. Real-time simulation represents a frequently applied methodology for analyzing the steady-state and transient behavior of electric power systems. This work introduces a guideline on how to model power electronics converters in digital real time simulators, taking into account the trade-off between model accuracy and the required computation time. Based on this concept, possible execution approaches with respect to the usage of central processing unit and field-programmable gate array components are highlighted. Simulation test scenario, such as primary frequency regulation and low voltage ride through, have been performed and accuracy indices are discussed for each implemented real-time model and each test scenario, respectively. Finally, a run-time analysis of presented real-time setups is given and real-time simulation results are compared. This manuscript demonstrates important differences in real-time simulation modelling, providing useful guidelines for the decision making of power engineers