Power Distribution(Hydro Power Plant) Transmission Line ACDC

By

Acknowledgement

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

Signed __________________ Date _________________

Abstract

This paper presents the concept of simultaneous ac-dc power transmission. Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits due to this instability occurs in the power system. With the scheme proposed in this paper, it is possible to load these lines very close to their thermal limits. The conductors are allowed to carry usual ac along dc superimposed on it. The advantage of parallel ac-dc transmission for improvement of transient stability and dynamic stability and damp out oscillations have been established

Table of Contents

1.0 INTRODUCTION6

1.1 Background of the Study6

1.1.1 Capacity and Environmental Considerations9

1.2 Research Aims11

1.3 Problem Definition11

1.4 Significance of the Study12

1.5 Ethical Concerns13

2.0 LITERATURE REVIEW15

2.1 Hydroelectric Power16

2.1.1 Generating Power17

2.1.2 Transmitting Power18

2.1.3 Hydropower -- From Past To Present18

2.2 AC vs. DC20

2.3 Existing Transmission Issues and Solution23

2.3.1 High Voltage DC Transmission23

Inherent problems associated with HVDC23

2.4 Concept of Simultaneous Ac-Dc Transmission25

2.5 Simultaneous Ac-Dc Power Transmission27

2.5.1 Economic consideration30

2.5.2 Protection31

3.0 RESEARCH METHODOLOGY33

3.1 Research Approach: Inductive or Deductive34

3.2 Research Design35

REFERENCES36

1.0 INTRODUCTION

1.1 Background of the Study

In recent years, environmental, right-of-way, and cost concerns have delayed the construction of a new transmission line, while demand of electric power has shown steady but geographically uneven growth. The power is often available at locations not close to the growing load centers but at remote locations. These locations are largely determined by regulatory policies, environmental acceptability, and the cost of available energy. The wheeling of this available energy through existing long ac lines to load centers has a certain upper limit due to stability considerations. Thus, these lines are not loaded to their thermal limit to keep sufficient margin against transient instability.

The present situation demands the review of traditional power transmission theory and practice, on the basis of new concepts that allow full utilization of existing transmission facilities without decreasing system availability and security. The flexible ac transmission system (FACTS) concepts, based on applying state-of-the-art power electronic technology to existing ac transmission system, improve stability to achieve power transmission close to its thermal limit (Machida, 1966, pp. 226).

The basic proof justifying the simultaneous ac-dc power transmission is explained in an IEEE paper “Simultaneous ac-dc power transmission,” by K. P. Basu and B. H. Khan. In the above reference, simultaneous ac-dc power transmission was first proposed through a single circuit ac transmission line. In these proposals Mono-polar dc transmission with ground as return path was used. There were certain limitations due to use of ground as return path. Moreover, the instantaneous value of each conductor voltage with respect to ground ...