Publications
A hybrid algorithm for parameter estimation (HAPE) for dynamic constant power loads
November 1, 2021
Journal Article
Published in:
IEEE Trans. Ind. Electron., Vol. 68, No. 11, November 2021, pp. 10326-35.
Summary
Low-inertia microgrids may easily have a single load which can make up most of the total load, thereby greatly affecting stability and power quality. Instead of a static load model, a dynamic constant power load (DCPL) model is considered here. Next, a hybrid algorithm for parameter estimation (HAPE) is introduced. In order to verify the load model and the HAPE, two experiments are conducted with different DCPLs using a Power-Hardwarein-the-Loop (PHiL) testbed. The PHiL testbed consists of a real-time computer working with a programmable power amplifier in order to perturb the input voltage's amplitude and frequency. Each connected DCPL in two separate experiments serves as the device under test (DUT). Using the captured experimental data as a reference, the HAPE is then invoked. The resulting parameter estimates are used to define simulation models. Both resulting DCPL models are simulated to produce waveforms that closely resemble experimental waveforms. Finally, the HAPE's resulting parameter estimates are presented, and the performance of the HAPE is discussed.
Summary
Low-inertia microgrids may easily have a single load which can make up most of the total load, thereby greatly affecting stability and power quality. Instead of a static load model, a dynamic constant power load (DCPL) model is considered here. Next, a hybrid algorithm for parameter estimation (HAPE) is introduced...
READ MORE
Toward distributed control for reconfigurable robust microgrids
October 11, 2020
Conference Paper
Published in:
2020 IEEE Energy Conversion Congress and Exposition, ECCE, 11-15 October 2020.
Summary
Microgrids have been seen as a good solution to providing power to forward-deployed military forces. However, compatibility, robustness and stability of current solutions are often questionable. To overcome some of these problems, we first propose a theoretically-sound modeling method which defines common microgrid component interfaces using power and rate of change of power. Using this modeling approach, we propose a multi-layered distributed control: the higher control layer participates in dynamic power management that ensures acceptable voltage, while the lower layer stabilizes frequency by regulating the dynamics to the power determined by the higher layer. Numerical and hardware tests are conducted to evaluate the effectiveness of the proposed control.
Summary
Microgrids have been seen as a good solution to providing power to forward-deployed military forces. However, compatibility, robustness and stability of current solutions are often questionable. To overcome some of these problems, we first propose a theoretically-sound modeling method which defines common microgrid component interfaces using power and rate of...
READ MORE
A workflow for non-linear load parameter estimation using a power-hardware-in-the-loop experimental testbed
March 15, 2020
Conference Paper
Published in:
2020 IEEE Applied Power Electronics Conf. and Expo., APEC, 15-19 March 2020.
Summary
Low-inertia microgrids may easily have a single load which can make up most of the total load, thereby greatly affecting stability and power quality. Instead of static load models, dynamic load models are presented here for constant current loads (CILs) and constant power loads (CPLs). Next, a flexible Power-Hardware-in-the-Loop (PHiL) testbed is employed for the experiments in this work. The PHiL testbed consists of a real-time computer working with a power amplifier in order to perturb its voltage and frequency. A connected load serves as the device under test (DUT). Using the captured experimental data as a reference, a parameter estimation algorithm is then implemented. The resulting parameter estimates are used to define simulation models. Both the CIL and CPL dynamic models are simulated to produce waveforms that closely resemble experimental waveforms. The algorithm, referred to as an enhanced monte carlo algorithm (EMCA), is explained in this work. Finally, the EMCA's resulting parameter estimates are presented.
Summary
Low-inertia microgrids may easily have a single load which can make up most of the total load, thereby greatly affecting stability and power quality. Instead of static load models, dynamic load models are presented here for constant current loads (CILs) and constant power loads (CPLs). Next, a flexible Power-Hardware-in-the-Loop (PHiL)...
READ MORE
Banshee distribution network benchmark and prototyping platform for hardware-in-the-loop integration of microgrid and device controllers
April 29, 2019
Journal Article
Published in:
J. Eng., Vol. 2019, No. 8, pp. 5365-73.
Topic:
R&D area:
Summary
This article provides a unique benchmark to integrate and systematically evaluate advanced functionalities of microgrid and downstream device controllers. The article describes Banshee, a real-life power distribution network. It also details a real-time controller hardware-in-the-loop (HIL) prototyping platform to test the responses of the controllers and verify decision-making algorithms. The benchmark aims to address power industry needs for a common basis to integrate and evaluate controllers for the overall microgrid, distributed energy resources (DERs), and protective devices. The test platform will accelerate microgrid deployment, enable standard compliance verification, and further develop and test controllers' functionalities. These contributions will facilitate safe and economical demonstrations of the state-of-the-possible while verifying minimal impact to existing electrical infrastructure. All aspects of the benchmark and platform development including models, configuration files, and documentation are publicly available via the electric power HIL controls collaborative (EPHCC).
Summary
This article provides a unique benchmark to integrate and systematically evaluate advanced functionalities of microgrid and downstream device controllers. The article describes Banshee, a real-life power distribution network. It also details a real-time controller hardware-in-the-loop (HIL) prototyping platform to test the responses of the controllers and verify decision-making algorithms. The...
READ MORE
Component standards for stable microgrids
October 12, 2018
Journal Article
Published in:
IEEE Trans. Power Syst., Vol. 34, No. 2, pp. 852-863. 2018.
Summary
This paper is motivated by the need to ensure fast microgrid stability. Modeling for purposes of establishing stability criterion and possible implementations are described. In particular, this paper proposes that highly heterogeneous microgrids comprising both conventional equipment and equipment based on rapidly emerging new technologies can be modeled as purely electric networks in order to provide intuitive insight into the issues of network stability. It is shown that the proposed model is valid for representing fast primary dynamics of diverse components (gensets, loads, PVs), assuming that slower variables are regulated by the higher-level controllers. Based on this modeling approach, an intuitively-appealing criterion is introduced requiring that components or their combined representations must behave as closed-loop passive electrical circuits. Implementing this criterion is illustrated using typical commercial feeder microgrid. Notably, these set the basis for standards which should be required for groups of components (sub grids) to ensure no fast instabilities in complex microgrids. Building the need for incrementally passive and monotonic characteristics into standards for network components may clarify the system level analysis and integration of microgrids.
Summary
This paper is motivated by the need to ensure fast microgrid stability. Modeling for purposes of establishing stability criterion and possible implementations are described. In particular, this paper proposes that highly heterogeneous microgrids comprising both conventional equipment and equipment based on rapidly emerging new technologies can be modeled as purely...
READ MORE
High performance computing techniques with power systems simulations
September 25, 2018
Conference Paper
Published in:
IEEE High Performance Extreme Computing Conf., HPEC, 25-27 September 2018.
Summary
Small electrical networks (i.e., microgrids) and machine models (synchronous generators, induction motors) can be simulated fairly easily, on sequential processes. However, running a large simulation on a single process becomes infeasible because of complexity and timing issues. Scalability becomes an increasingly important issue for larger simulations, and the platform for running such large simulations, like the MIT Supercloud, becomes more important. The distributed computing network used to simulate an electrical network as the physical system presents new challenges, however. Different simulation models, different time steps, and different computation times for each process in the distributed computing network introduce new challenges not present with typical problems that are addressed with high performance computing techniques. A distributed computing network is established for some example electrical networks, and then adjustments are made in the parallel simulation set-up to alleviate the new kinds of challenges that come with modeling and simulating a physical system as diverse as an electrical network. Also, methods are shown to simulate the same electrical network in hundreds of milliseconds, as opposed to several seconds--a dramatic speedup once the simulation is parallelized.
Summary
Small electrical networks (i.e., microgrids) and machine models (synchronous generators, induction motors) can be simulated fairly easily, on sequential processes. However, running a large simulation on a single process becomes infeasible because of complexity and timing issues. Scalability becomes an increasingly important issue for larger simulations, and the platform for...
READ MORE
Predicting exploitation of disclosed software vulnerabilities using open-source data
March 24, 2017
Conference Paper
Published in:
3rd ACM Int. Workshop on Security and Privacy Analytics, IWSPA 2017, 24 March 2017.
Topic:
R&D area:
Summary
Each year, thousands of software vulnerabilities are discovered and reported to the public. Unpatched known vulnerabilities are a significant security risk. It is imperative that software vendors quickly provide patches once vulnerabilities are known and users quickly install those patches as soon as they are available. However, most vulnerabilities are never actually exploited. Since writing, testing, and installing software patches can involve considerable resources, it would be desirable to prioritize the remediation of vulnerabilities that are likely to be exploited. Several published research studies have reported moderate success in applying machine learning techniques to the task of predicting whether a vulnerability will be exploited. These approaches typically use features derived from vulnerability databases (such as the summary text describing the vulnerability) or social media posts that mention the vulnerability by name. However, these prior studies share multiple methodological shortcomings that infl ate predictive power of these approaches. We replicate key portions of the prior work, compare their approaches, and show how selection of training and test data critically affect the estimated performance of predictive models. The results of this study point to important methodological considerations that should be taken into account so that results reflect real-world utility.
Summary
Each year, thousands of software vulnerabilities are discovered and reported to the public. Unpatched known vulnerabilities are a significant security risk. It is imperative that software vendors quickly provide patches once vulnerabilities are known and users quickly install those patches as soon as they are available. However, most vulnerabilities are...
READ MORE
Development of a real-time hardware-in-the-loop power systems simulation platform to evaluate commercial microgrid controllers
February 23, 2016
Technical Report
Published in:
MIT Lincoln Laboratory Report TR-1203
Topic:
R&D area:
Summary
This report describes the development of a real-time hardware-in-the-loop (HIL) power system simulation platform to evaluate commercial microgrid controllers. The effort resulted in the successful demonstration of HIL simulation technology at a Technical Symposium organized by the Mass Clean Energy Center (CEC) for utility distribution system engineers, project developers, systems integrators, equipment vendors, academia, regulators, City of Boston officials, and Commonwealth officials. Actual microgrid controller hardware was integrated along with actual, commercial genset controller hardware in a particular microgrid configuration, which included dynamic loads, distributed energy resources (DERs), and conventional power sources. The end product provides the ability to quickly and cost-effectively assess the performance of different microgrid controllers as quantified by certain metrics, such as fuel consumption, power flow management precision at the point of common coupling, load-not-served (LNS) while islanded, peak-shaving kWh, and voltage stability. Additional applications include protection system testing and evaluation, distributed generation prime mover controller testing, integration and testing of distribution control systems, behavior testing and studies of DER controls, detailed power systems analysis, communications testing and integration, and implementation and evaluation of smart grid concepts. Microgrids and these additional applications promise to improve the reliability, resiliency, and efficiency of the nation's aging but critical power distribution systems. This achievement was a collaborative effort between MIT Lincoln Laboratory and industry microgrid controller manufacturers. This work was sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate (S&T) and the Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability.
Summary
This report describes the development of a real-time hardware-in-the-loop (HIL) power system simulation platform to evaluate commercial microgrid controllers. The effort resulted in the successful demonstration of HIL simulation technology at a Technical Symposium organized by the Mass Clean Energy Center (CEC) for utility distribution system engineers, project developers, systems...
READ MORE