Ferenc Bogdan

Controller and Power Hardware-In-Loop Methods for Accelerating Renewable Energy Integration

This paper describes the basic concepts behind controller hardware-in-the-loop (CHIL) and power hardware-in- the-loop (PHIL) experimental testing from a renewable energy system integration perspective. An entire power apparatus or sub-system such as a power electronics converter for a fuel cell system or a variable speed wind power generator system can be tested in a controlled laboratory environment such as the 5 MW rated hardware-in-the-Loop (HIL) test facility established at the Center for Advanced Power Systems at Florida State University.

Power hardware-in-the-loop testing of a 500 kW photovoltaic array inverter

The testing of a 500 kW photovoltaic array inverter using power hardware-in-the-loop simulation is described. A real-time simulator is used with a DC amplifier in order to emulate a photovoltaic (PV) array and an AC amplifier to emulate a power grid. The test setup is described in detail and a range of tests that were conducted on the inverter are summarized.

Testing a 5 MW high-temperature superconducting propulsion motor

A prototype marine propulsion motor manufactured by American Superconductor Corporation has been tested in the advanced test facility at the Center for Advanced Power Systems at Florida State University. The rotor of this 5 MW synchronous machine is constructed of high-temperature superconducting wire; the three-phase stator is of conventional wire. Testing was conducted with a dynamometer consisting of two 2.5 MW induction motors which permitted a wide range of conventional and novel procedures to be carried out for the characterization of the HTS motor. These tests and some of their results are discussed. The HTS motor functioned satisfactorily in all tests.

Multifunctional megawatt scale medium voltage DC test bed based on modular multilevel converter (MMC) technology

The recent development of modular multilevel converters (MMC) provides new opportunities for medium voltage DC (MVDC) systems for all electric ship design and offshore wind parks. Therefore, the Center for Advanced Power Systems at Florida State University has recently commissioned a new MVDC power-hardware-in-the-loop laboratory rated at 5 MW at DC voltages between 6...24 kV. The new lab features four individual MMCs, each composed of 36 full-bridge cells, and capable of delivering 210 A at 0...6 kV. This paper describes the entire system in detail, including the advanced current and voltage control concepts along with the state of the art digital control hardware. Selected commissioning results demonstrate the performance of the system under dynamic conditions and provide comparison with simulations obtained from a corresponding controller hardware-in-the-loop setup which is also described in the paper.

Performance of 2G HTS Tapes in Sub-Cooled LN2 for Superconducting Fault Current Limiting Applications

Within the past few years a newer, more robust type of superconductor known as 2nd Generation High Temperature Superconductor (HTS) wire, has become available in sufficient quantity and lengths for developers to build prototype devices and test their capabilities. This new material offers the potential for revolutionary changes in superconducting transformers and Super conducting Fault Current Limiters to enable better thermal stability and fast quenching capabilities that can meet the stringent demands of large transient faults for distribution and transmission power lines. This manuscript discusses the manufacturing and latest tests and capabilities of sub-cooled superconducting fault current limiter device and modules designed for distribution and trans mission lines. We will also discuss the advantages and superior performance of the new 2nd Generation HTS superconductors under sub-cooled liquid nitrogen operation when used in super conducting fault current limiters. The feasibility demonstration and performance of sub-cooled SFCL superconducting modules for distribution and transmission SFCL devices will be discussed.

Hardware-in-the-Loop Investigation of Rotor Heating in a 5 MW HTS Propulsion Motor

Of particular concern to designers of HTS machines are potential heating effects in the superconducting windings due to AC losses caused by load fluctuations encountered in real-life operating conditions. A 5 MW HTS synchronous prototype ship propulsion motor has been tested extensively under steady-state and dynamic load conditions in the advanced test facility of the Center for Advanced Power Systems at Florida State University. This paper presents results from two tests of rotor heating effects, one employing single frequency torque oscillations and the other more realistic load modeling of sea-states by means of hardware-in-the-loop (HIL) real-time simulations. Temperature results from 4 different torque oscillation tests and 12 different sea-state tests provide rotor-heating information, obtained from multiple temperature sensor data within the HTS rotor, and are compared with data obtained from steady-state runs.

Hardware-In-the-Loop Experiments with a 5 MW HTS Propulsion Motor at Florida State University's Power Test Facility

Some aspects unique to the emerging high temperature superconducting (HTS) rotating machinery technology, such as increased AC losses in the HTS winding of the rotor circuit due to low frequency load changes, requires advanced experimental methods for R&D testing and, eventually, type testing. Therefore, this paper describes a novel 5 MW rated hardware-in-the-loop (HIL) test facility established at the center for advanced power systems at Florida State University. Integrated with a state-of-the-art digital real-time simulator this facility allows for highly complex HIL experiments in order to subject devices under test to realistic, real-life operating conditions. In particular, the paper discusses experiences from the worlds first HIL test of a 5 MW HTS synchronous machine, designed and built as a prototype ship propulsion motor technology demonstrator. During sea-state tests, a sophisticated hydrodynamic simulation model - incorporating random wave height and frequency spectra, simulated ship velocity, and the actual motor speed feedback - provided real-time torque reference signals to dynamometers loading the HTS motor. Results from HIL tests are provided and discussed in addition to an outlook on additional experimental procedures which could be applied to HTS machines for better characterization and even more rigorous real-life testing.

Test environment for a novel medium voltage impedance measurement unit

Small signal stability of converter-based power distribution systems can be evaluated with the help of impedance characterization, which provides a means to predict the effect of interactions. These techniques have great Navy relevance as future ships may be based on medium voltage distribution networks of interconnected feedback-controlled switching power converters. These networks will be subject to converter interactions and potential instability. This paper summarizes work done to prepare full scale testing of the first medium voltage, MW scale impedance measurement unit which was recently developed using SiC technology.

Modular multilevel converter based test bed for mvdc applications — A case study with a 12 kV, 5 MW setup

The Modular Multilevel Converter (MMC) topology has a wide area of possible applications. Features like redundancy at the module level and fault current limiting capability makes it a robust solution for many power applications. Moreover, this topology is very useful as a test equipment for Power Hardware in-the-Loop simulations, especially as a DC grid simulator. This paper describes a recently commissioned MMC based test bed built with four MMCs capable to operate at up to 5 MW power at 6 to 24 kV, depending upon which system configuration is chosen. Test results for the 12 kV configuration are presented along with a detailed description of all the salient control modules. It is concluded that due to its flexibility, this MVDC laboratory can serve the research and development community in addressing and de-risking a broad range of system integration and technology challenges.

Megawatt-scale power hardware-in-the-loop simulation testing of a power conversion module for naval applications

In June through October of 2014, power-hardware-in-the-loop (PHIL) simulation testing of a 1.2 MW, 4.16 kV AC / 1 kV DC power conversion module for naval applications was conducted. In these tests, the device-under-test (DUT) was interfaced to a virtual surrounding system that was generally representative of the power system of a future surface combatant. Tests were focused on demonstration of operation and performance of the DUT through dynamic conditions in a realistic environment, collection of data for characterization and validation of models of the DUT, and collection of data for assessment of the accuracy and suitability of the approach for testing future power conversion modules. These tests were the culmination of numerous coordinated efforts over preceding months to identify, implement, and verify the necessary surrounding systems and supporting models, define meaningful test procedures, and develop, implement, and test appropriate controls and protection systems. The tests successfully concluded with a large amount of data of the behavior of the DUT under a wide range of expected system conditions. Moreover, this project identified the need to further develop PHIL interface algorithms such as the damped impedance method to improve accuracy and stability of future PHIL experiments at the megawatt scale.