Alexandra von Meier

Alexandra von Meier
University of California, Berkeley | UCB · Department of Electrical Engineering and Computer Sciences

PhD

About

57
Publications
15,208
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1,601
Citations
Introduction

Publications

Publications (57)
Preprint
In this paper, we introduce Voltage Phasor Control (VPC), also known as Phasor Based Control, as a novel way of implementing Optimal Power Flow (OPF). Unlike conventional OPF, in which the power flow optimization broadcasts power injections, the VPC power flow optimization broadcasts voltage phasor setpoints to feedback controllers distributed thro...
Preprint
Full-text available
As more distributed energy resources (DERs) are connected to the power grid, it becomes increasingly important to ensure safe and effective coordination between legacy voltage regulation devices and inverter-based DERs. In this work, we show how a distribution circuit model, composed of two LTCs and two inverter devices, can create voltage oscillat...
Preprint
Full-text available
In this work we explore impedance-based interactions that arise when inverter-connected distributed energy resources (DERs) inject real and reactive power to regulate voltage and power flows on three-phase unbalanced distribution grids. We consider two inverter control frameworks that compute power setpoints: a mix of volt/var and volt/watt control...
Article
We present a method for joint phase identification and topology recovery in unbalanced three phase radial networks using only voltage measurements. By recovering phases and topology jointly, we utilize all three phase voltage measurements and can handle networks where some buses have a subset of three phases. Our method is theoretically justified b...
Article
Phasor Based Control is a novel approach to controlling Distributed Energy Resources that aims at relieving various constraints that arise in the distribution grid. It is a two-layer control system with a supervisory control that coordinates distributed controllers to reach voltage phasor targets. The distributed controllers use local synchrophasor...
Preprint
Full-text available
We present a method for evaluating the placement of Distributed Energy Resources (DER) on distribution circuits in order to control voltages and power flows. Our previous work described Phasor-Based Control (PBC), a novel control framework where DERs inject real and reactive power to track voltage magnitude and phase angle targets. Here, we employ...
Chapter
This chapter focuses on technological innovations in electric power infrastructure and their enabling potential for the integration of variable generation resources, electric vehicles (EVs), and microgrids. Many of the innovations described in this chapter were driven by evolving technical and economic constraints that long predated renewable grids...
Preprint
We present a method for joint phase identification and topology recovery from voltage measurements in unbalanced three phase radial networks. By recovering phases and topology jointly, we make use of all three phase measurements and can handle networks where some buses have only a subset of three phases. Our method is theoretically justified by a n...
Article
Full-text available
We propose an innovative framework termed phasor-based control (PBC) to facilitate the integration of heterogeneous and intermittent distributed energy resources (DER) on the electric grid. PBC presents a unified approach that is agnostic to optimization criteria and to the particular characteristics of participating resources. It is enabled by syn...
Article
Distributed energy resource (DER) owners experience a loss in economic benefits due to prolonged and/or frequent inverter disconnection. In this paper, we investigate the economic savings that customers accrue when combining rooftop solar photovoltaic (PV) generation with battery storage systems, considering a time-of-use pricing tariff and the ste...
Article
Full-text available
The availability of accurate measurements is the prerequisite for the actual implementation of many monitoring and management applications in smart distribution networks. Phasor Measurement Units (PMUs) can provide synchronized voltage and current measurements, referred to a common time reference (usually the Coordinated Universal Time, UTC). This...
Article
Full-text available
Effective monitoring and management applications on modern distribution networks (DNs) require a sound network model and the knowledge of line parameters. Network line impedances are used, among other things, for state estimation and protection relay setting. Phasor measurement units (PMUs) give synchronized voltage and current phasor measurements,...
Technical Report
Full-text available
The purpose of this white paper is to provide an introductory reference for industry and academic practitioners interested in exploring the use of synchrophasors and other time-synchronized measurements for supporting power distribution system planning, operation, and research. This paper is motivated by the belief that effective measurement and an...
Chapter
Historically, with mostly radial power distribution and one-way power flow, it was only necessary to evaluate the envelope of design conditions, e.g., peak loads or fault currents, rather than continually observe the operating state. But the growth of distributed energy resources introduces variability, uncertainty, and opportunities to recruit div...
Article
Full-text available
This paper describes high-level findings from an innovative network of high-precision phasor measurement units, or micro-PMUs (μPMUs), designed to provide an unprecedented level of visibility for power distribution systems. We present capabilities of the technology developed in the course of a three-year ARPA-E funded project, along with challenges...
Conference Paper
Full-text available
In this paper, we conduct a data-driven experimental analysis on capacitor bank switching event at a distribution grid in Riverside, CA using data from two distribution level phasor measurement units, a.k.a, Micro-PMUs. Of particular interest was to detect the capacitor bank switching events based on feeder-level and load-level Micro-PMUs and thus...
Conference Paper
Full-text available
Power system has been incorporating increasing amount of unconventional generations and loads such as renewable resources, electric vehicles, and controllable loads. The induced short term and stochastic power flow requires high resolution monitoring technology and agile decision support techniques for system diagnosis and control. In this paper, w...
Article
Full-text available
In recent years, advanced sensors, intelligent automation, communication networks, and information technologies have been integrated into the electric grid to enhance its performance and efficiency. Integrating these new technologies has resulted in more interconnections and interdependencies between the physical and cyber components of the grid. N...
Conference Paper
Full-text available
The distribution grid is changing to become an active resource with complex modeling needs. The new active distribution grid will, within the next ten years, contain a complex mix of load, generation, storage and automated resources all operating with different objectives on different time scales from each other and requiring detailed analysis. Ele...
Conference Paper
Full-text available
This paper analyzes impacts and interactions of harmonics from multiple sources, especially distributed energy resources, on distribution networks. We propose a new index, the Phasor Harmonic Index (PHI), that considers both harmonic source magnitude and phase angle, while other commonly used harmonic indices are based solely on magnitude of wavef...
Article
Full-text available
This paper proposes a novel approach for detecting the topology of distribution networks based on the analysis of time series measurements. The time-based analysis approach draws on data from high-precision phasor measurement units (PMUs or synchrophasors) for distribution systems. A key fact is that time-series data taken from a dynamic system sho...
Article
Full-text available
This paper proposes a data-driven approach to detect the switching actions and topology transitions in distribution networks. It is based on the real time analysis of time-series voltages measurements. The analysis approach draws on data from high-precision phasor measurement units ($\mu$PMUs or synchrophasors) for distribution networks. The key fa...
Article
Full-text available
Diversity of software packages to simulate the power system circuits is considerable. It is challenging to transfer power system circuit model data (PSCMD) among different software tools and rebuild the same circuit in the second software environment. This paper proposes a unified platform (UP) where PSCMD are stored in a spreadsheet file with a de...
Conference Paper
Full-text available
This paper proposes a novel approach to detectingthe topology of distribution networks based on the analysisof time series measurements. The analysis approach draws ondata from high-precision phasor measurement units (PMUs orsynchrophasors) for distribution systems. A key fact is that time-series data taken from a dynamic system show specific patter...
Article
Full-text available
This paper proposes a novel phase identification method for distribution networks where phases can be severely unbalanced and insufficiently labeled. The analysis approach draws on data from high-precision phasor measurement units (micro-synchrophasors or uPMUs) for distribution systems. A key fact is that time-series voltage phasors taken from a d...
Article
Full-text available
Network topology in distribution networks is often unknown, because most switches are not equipped with measurement devices and communication links. However, knowledge about the actual topology is critical for safe and reliable grid operation. This paper proposes a voting-based topology detection method based on micro-synchrophasor measurements. Th...
Conference Paper
Full-text available
In this work we address the problem of static state estimation (SE) in distribution grids by leveraging historical meter data (pseudo-measurements) with real-time measurements from synchrophasors (PMU data). We present a Bayesian linear estimator based on a linear approximation of the power flow equations for distribution networks, which is computa...
Article
Full-text available
In recent years, extreme weather events have severely affected the performance of the electric grid. Very large-scale events (VLSE) with potentially catastrophic impacts on the grid pose more than an inconvenience in today?s electricity-driven lifestyle, and the frequency and severity of such events may continue to increase as a consequence of glob...
Article
Full-text available
Historically, with mostly radial power distribution and one-way power flow, it was only necessary to evaluate the envelope of design conditions, e.g., peak loads or fault currents, rather than continually observe the operating state. But the growth of distributed energy resources introduces variability, uncertainty, and opportunities to recruit div...
Article
Full-text available
This paper analyzes impacts and interactions of harmonics from multiple sources, especially distributed energy resources, on distribution networks. We propose a new index, the Phasor Harmonic Index (PHI), that considers both harmonic source magnitude and phase angle, while other commonly used harmonic indices are based solely on magnitude of wavefo...
Conference Paper
Full-text available
This paper describes challenges for integrating high fidelity data with utility distribution operations. Two research projects are described microsynchrophasors (µPMU) and OpenPMU and explore the applications of data for electric power distribution systems.
Chapter
Historically, power distribution systems did not require elaborate monitoring schemes. With radial topology and one-way power flow, it was only necessary to evaluate the envelope of design conditions (i.e., peak loads or fault currents), rather than continually observe the operating state. But the growth of distributed energy resources, such as ren...
Conference Paper
Full-text available
This paper describes a research project to develop a network of high-precision phasor measurement units, termed micro-synchrophasors or μPMUs, and explore the applications of μPMU data for electric power distribution systems.
Conference Paper
This paper presents a strategic overview for the planning and implementation of monitoring programs to evaluate and analyze impacts of distributed energy resources (DER) on electric distribution systems. The paper presents technical considerations for determining measurement strategies to evaluate specific operational impacts, to inform analytic st...
Article
Full-text available
The successful integration of intermittent and distributed electric generation from renewable resources can be viewed as a coordination problem at multiple scales in both space and time. This paper presents an overview of coordination issues relative to the goals for renewable integration in California.

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Projects

Projects (2)
Project
Today’s electric power distribution systems have limited observability and diagnostic capabilities. In high-voltage power transmission, visibility and situational awareness have been a vital area for technological R&D and investment in recent years. Distribution systems are lagging several decades behind, for good reason: there was historically no need, nor a business case, to develop similar capabilities. Owing to the relative simplicity of power distribution – i.e., mostly radial layout of circuits with one-way power flow – it was necessary only to evaluate the envelope of design operating conditions (such as peak loads or fault currents) rather than continually observe the actual operating state. Accordingly, legacy distribution circuits are equipped with little instrumentation beyond the substation. But the growth of distributed energy resources (DER) such as solar photovoltaics, electric vehicles, automated demand response and distributed storage introduces significant variability and new uncertainties, as well as opportunities to recruit diverse resources for grid services. This development dramatically increases the need and value proposition for tools to better observe, understand and manage the grid at the distribution scale. For more information feel free to contact Dr. Reza Arghandeh, FSU and Dr. Alexandra von Meier, UC Berkeley.
Project
The Grid Integration Group at LBNL has released a real world distribution synchrophasor dataset for research and development use. The data was measured over a 3 month time period on the LBNL grid, utilizing new μPMU sensors developed by Power Standards Laboratory, installed via the ARPA-E project “micro-synchrophasors for distribution”. The data collected includes 120 samples/second of voltage and current magnitude and phase angle. The data is accessible through multiple formats, including a direct download of compressed files, or visualized through the Berkeley Tree Database (BTrDB) interface.