Power hardware in the loop platform for flywheel energy storage system testing for electric ship power system applications

The UK MoD and Power Networks Demonstration Centre (PNDC) have worked collaboratively to de-risk the integration of power system architecture into future and legacy naval platforms This is being achieved through the development of a 540kVA Power Hardware in the Loop (PHIL) testing facility as part of a project arrangement with the US called "The Advanced Electrical Power and Propulsion Systems Development Project." The two key components of the PHIL system are: (1) A real time digital simulator system that is capable of simulating naval electrical systems in real time; and (2) A programmable power converter, a uniquely modular solution that can be re-configured for AC and DC output, which is used as the link between simulation and real hardware under test. The PHIL testbed has been used to investigate a 360kW modular flywheel system developed by GKN. This project involved interfacing the real flywheel to a simulated ship electrical power system. This paper discusses how the PHIL test facility was configured for flywheel testing and the associated challenges, learnings and opportunities from this test setup. This paper also reports on one of the tests that was completed as part of this test program. In this test the FESS is operating in real time connected to a ship power system simulation. The results reported in this paper are particularly significant in that they demonstrate how a real piece of hardware can be tested as part of a ship power system without the need for a full ship demonstrator. This form of testing supports rapid resolution of hardware to ship integration challenges, control methodologies, and power system management schemes for de-risking new systems. This testing is prior to the hardware being connected to any potential full-scale shore based ship demonstrator or being installed directly on-board a ship power system where it could adversely impact ship operation

Development of a geographically distributed real-time test facility

Europe's electric power network is entering a period of extreme flux as we move to an era where it is dominated by non-linear, asynchronous generation such as wind power plants. The rapid rise of new technologies in this space has led to increasingly complex interactions within the power network that are difficult to cover through traditional test regimes. Existing facilities are not fully equipped to address these new system orientated challenges and while investing in new sites and facilities is one way forward, this is likely to be prohibitively expensive and runs the risk of only being applicable to niche applications. This work presents the first stage in an alternative approach which seeks to address these challenges through the pooling of existing resources. In this concept, geographically distributed test facilities are combined virtually to create new capabilities and perform complex system level validations. This can be done through a Geographically Distributed – Power Hardware in the Loop (GD-PHIL) setup. To achieve this, each site requires a PHIL setup allowing the Device Under Test (DUT) to interact in real time with a simulation. This work will present the outcome of the first step towards the development of such a network, developing and demonstrating the stable communications interfaces necessary to link geographically distributed real time simulators from two different manufacturers

Performance optimisation of a flywheel energy storage system using the PNDC power hardware in the loop platform

The UK MOD has an objective to improve the efficiency and flexibility associated with the integration of naval electrical systems into both new & existing platforms. A more specific challenge for the MOD is in the de-risking of the integration of future pulse & stochastic loads such as Laser Directed Energy Weapons. To address this the Power Networks Demonstration Centre (PNDC) naval research programme is focused towards understanding & resolving the associated future power system requirements. To address these challenges, the UK MOD and the PNDC have worked collaboratively to develop a 540kVA Power Hardware in the Loop (PHIL) testing facility. For the UK MOD this supports the “UK-US Advanced Electric Power and Propulsion Project Arrangement (AEP3).” This testing facility has been used to explore the capabilities of PHIL testing and evaluate a Flywheel Energy Storage System (FESS) in a notional ship power system environment. This testing provided an opportunity to develop and further validate the capability of the PHIL platform for continued marine power system research. This paper presents on the results from PHIL testing of the FESS at PNDC, which involved both characterisation and interfacing the FESS within a simulated ship power system. The characterisation tests involved evaluating the: response to step changes in current reference; frequency and impedance characteristics; and response during uncontrolled discharge. The ship power system testing involved interfacing the FESS to a simulated real time notional ship power system model and evaluating the response of the FESS and the impact on the ship power system under a range of different operational scenarios. This paper also discuss the links between FESS characterisation testing and the development of the energy management system implemented in the real time model. This control system was developed to schedule operation of the FESS state (charging, discharging and idle) with the other simulated generation sources (the active front end and battery storage) and with the loads within the ship power system model. Finally, this paper highlights how the testing at PNDC has also supported the comparison and validation of previous FESS testing at Florida State University’s Centre Advanced Power Systems (FSU CAPS) facility, and how the combined efforts help to collectively de-risk future load Total Ship Integration and Evolving Intelligent Platforms in both UK and US programmes via the AEP3 PA

The role of experimental test beds for the systems testing of future marine electrical power systems

Marine electrical power systems (MEPS) are experiencing a progressive change with increased electrification - incorporation of distributed power generation, high power density requirement, increased storage integration, availability of alternative technologies and incorporation of novel loads to name a few. In recent years, smart grid (advanced land based power systems) concepts have increasingly been incorporated within MEPS to leverage on their proven advantages. Due to the distinct nature of the two power systems, upon incorporation, the solutions need to be further proven by simulations and experimentation. This paper presents two smart grid enabled MEPS test beds at the University of Strathclyde developed to allow for proof of concept validations, prototyping, component characterization, test driven development/enhancement of emerging MEPS solutions, technologies and architectures. The capabilities of the test beds for rapid proof of concept validations and component characterization are discussed by means of two case studies. Drawing on from the two case studies, this paper further presents a discussion on the requirements of systems testing of future more electric MEPS