Document Type

Thesis - Open Access

Award Date

2018

Degree Name

Master of Science (MS)

Department / School

Electrical Engineering and Computer Science

First Advisor

Timothy M. Hansen

Second Advisor

Robert Fourney

Keywords

Active power curtailment (APC), Active reactive power management, GridLAB-D, Overvoltage prevention, Quasi-steady-state time-series (QSTS), real-time price (RTP)

Abstract

Voltage-rise due to increasing installation of photovoltaic (PV) systems is a major technical issue in low voltage distribution networks. A cost-effective approach to address the overvoltage problem is to control the active and reactive power provided by the existing PV inverters. Prior research used electro-magnetic transient (EMT) simulation tools to develop inverter control strategies for overvoltage prevention. These type of simulation requires high computational resources and simulation time, and is therefore not suitable for long time period studies (e.g., annual) with many inverters. With the anticipated high penetration of PV, there is a desire for a suitable tool for long time-horizon simulation studies to perform technical and economic analysis. This research work describes the use of quasi-steady-state time-series (QSTS) software (GridLAB-D) to implement inverter overvoltage prevention strategies (formerly developed using EMT simulation), allowing previously infeasible long-term techno-economic analysis of such controllers. A co-simulation framework is used to coordinate the PV inverter controllers implemented in Python on a 12-house low voltage distribution network model developed in GridLAB-D. Three PV inverter controllers are implemented to evaluate the long term technical and economic aspects, including voltage profile analysis, energy generation and consumption, system losses, and transformer loading. Two different pricing structures, real-time pricing (RTP) and flat rate tariff, have been considered in the economic analysis. It is shown that with high penetration of PV and use of effective inverter controllers, the financial benefit to the end-users increases significantly when a net metering policy is used to trade electricity in either tariff scheme. This, however, caused a reduction in the utility electricity sales, and governmental taxes, possibly leading to increased electric rates over time. In addition a 216 house 3 phase distribution feeder is developed in GridLAB-D which can further be used for evaluating different PV inverter controller for large test case system.

Library of Congress Subject Headings

Photovoltaic power systems.
Electric inverters -- Technological innovations.
Electric controllers -- Technological innovations.
Electric power production.
Low voltage systems.

Description

Includes bibliographical references

Format

application/pdf

Number of Pages

76

Publisher

South Dakota State University

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Rights Statement

In Copyright