EE 2303 TRANSMISSION AND DISTRIBUTION

OBJECTIVE

To become familiar with the function of different components used in Transmission and Distribution levels of power systems and modeling of these components.

OBJECTIVESTo develop expression for computation of fundamental parameters of lines.To categorize the lines into different classes and develop equivalent circuits for these classes.To analyse the voltage distribution in insulator strings and cables and methods to improve the same.

INTRODUCTION

INTRODUCTION

INTRODUCTION

Various levels such as generation, transmission and distribution.

INTRODUCTIONHVDC High voltage direct current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids. When electrical energy is required to be transmitted over very long distances, it is more economical to transmit using direct current instead of alternating current.

INTRODUCTIONEHV AC transmission Hydro-electric and coal or oil-fired stations are located very far from load centres for variousreasons which requires the transmission of the generated electric power over very long distances.This requires very high voltages for transmission. The very rapid strides taken by developmentof dc transmission since 1950 is playing a major role in extra-long-distance transmission,complementing or supplementing EHV AC transmission.

INTRODUCTIONTechnical performance and reliability Considerations in the design of a power line: The amount of active power it has to transmit The distance over which the power must be carried The cost of the power line Aesthetic considerations, urban congestion, ease of installation, expected load growth

INTRODUCTIONApplication of HVDC transmission system HVDC Light, is utilising state of the art semiconductors,control and cable insulation and can offer many new transmission opportunities as has been demonstrated by actual projects above. It offers a lot of possibilities to enhance the power systems.Wind power, even big parks, can easily be connected to the grid. In many cases HVDC Light can give new opportunities to trade electric energy in the new deregulated markets. As HVDC Light has been developed to minimise environmental impact and impact on the connecting grids, the licence procedure is generally more favourable than more traditional solutions.

INTRODUCTIONFACTS

INTRODUCTIONTCSC

The Thyristor Controlled Series Capacitor (TCSC) seems to be one of the members within the FACTS family, beside the SVC that was established long ago, which has attracted the most interest so far. One reason may be that a distinctive quality of the TCSC concept isthat it uses an extremely simple main circuit topology.

The capacitor is inserted directly in series with the transmission line and the thyristor controlled inductor is mounted directly in parallel with the capacitor. Thus no interfacing equipment like e.g. high voltage transformers is required. This makes TCSC much more economical than some other competing FACTS technologies.

INTRODUCTIONSVC Static variable capacitor Parallel-connected static var generator or absorber Output is adjusted to exchange capacitive or inductive current. Maintain or control specific parameters of the electrical power system (typically bus voltage). Thyristor-based Controllers Lower cost alternative to STATCOM

INTRODUCTIONSTATCOM Static Synchronous Compensator (STATCOM)Parallel-connected static var compensatorCapacitive or inductive output current controlled independently of the ac system voltage

INTRODUCTIONUPFC Unified power flow controller (UPFC) is one of the FACTS devices, which can control power system parameters such as terminal voltage, line impedance and phase angle. Therefore, it can be used not only for power flow control, but also for power system stabilizing control.

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