Fault Induced Delayed Voltage Recovery

Table of Contents

Introduction3

Information Acquisition3

Voltage Regulation3

Voltage Sag7

Impact of Voltage sags9

DVR10

Compensation Techniques13

Sag Detection Technique14

Control Techniques15

Fault Induced Delayed Voltage Recovery16

FIDVR Root Cause18

Solution for FIDVR events19

Customer level solutions20

System Solutions21

Efficient and fast Fault clearing23

Addition of reactive supply24

Limitation of load24

Protection methods24

Fault details26

Structural limitations load model26

Load Model Data Uncertainties26

Power plant behaviour27

Lack of events and data for model validation27

Positive-sequence simulator limitations28

Improve FIDVR monitoring29

Continue improvement of power system models with respect to FIDVR30

Introducing composite load model to planning and operating entities in WECC30

Manual load shedding31

Distributed / Local UVLS Schemes32

Centralized / Wide area undervoltage load shedding34

FIDVR Scenario35

Recommendation37

Conclusion38

Fault Induced Delayed Voltage Recovery

Introduction

The problem or issue that forces me to select this topic is the risk available in power systems voltage distribution and the events related to FIDVR. The transmission providers that are the stations and substations of electricity along with the customers may get greatly affected by the problems that rise due to FIDVR (Hilton, 2012).

Information Acquisition

The measurements of choice for literature were relevancy to research topic and year of public. Both public and individual libraries as well as online libraries were chaffered to approach the data. Facts were accumulated to support the study that has been conveyed. However, a literature too old to appropriate the search and the topic was excluded (to some extent) from this research and analysis. Only the latest figures which were sufficient enough to assist the exploration and illustration were utilized. To gather proper information about the study, scholarly articles were searched and considered. Some of online databases that were accessed are Google Scholar, SAGE, Questia, Emerald, Pro-quest, EBSCO and so on.

Voltage Regulation

Voltage regulation can be defined as the ability to control a system with constant voltage that is regulating in a variable range of load conditions. The modern power systems and electric stations work at a standard voltage mode. The equipments and systems used in voltage regulation are being provided with the standard voltage with a certain level of tolerance limit. A transformer is also being induced for voltage regulation. However there is also some voltage drops related to the transformer as well. The input voltage in this situation may not be a concern, but the voltage load based on the transformer is the issue. This is because if the voltage load in the transformer is a drop then this would affect the performance of the voltage system. This shows the importance of voltage regulation to be maintained when there is a drop in the load current or is being drawn from the output. This drop of voltage in power systems is known as voltage regulation. It can also be defined as the relative ratio between the terminal voltages. (Williams, Schmus, Dawson, 1992) (Bardi, 2003).

Over the voltage regulation the ratio between the line voltage and load situation in the network is adjusted according to each other. Over a selection switch on the transformer turns ratio connected, which represents the new power supply. In the simplest case, stabilizes the voltage regulation, the voltage for a single transformer is however also the ...