Download - Improving Power Quality Using Distribution Design

Technical Seminar Presentation

December 24, 2004 [1/12]

IMPROVING POWER QUALITY USING DISTRIBUTION DESIGN

Presented By:

AMIT KUMAR ROLL NO. EE200118062

Under guidance of MR. DEBASIS JENA

Instructor


AMIT KUMAR # EE200118062 [2/12]

•power quality Is the physical characteristics of the electrical supply provided under normal operating conditions that do not disrupt or disturb the customer’s processes .

• quality of power supply implies basically voltage quality and supply reliability.

• power quality issues is an increasingly important factor to consider in

order to satisfy good productivity

POWER QUALITY- Introduction

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AMIT KUMAR # EE200118062 [3/12]

• LONG-DURATION VARIATIONS: Rms deviations at power frequencies for longer than one minute.

. Long-duration variations can be caused by: -

- Improper voltage regulation

- Broken neutral

- Utility-initiated voltage reduction

- Sudden change of load or unusual load on a distribution circuit

VOLTAGE REGULATION VARIATION

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AMIT KUMAR # EE200118062 [4/12]

•power quality problem exists if any voltage, current or frequency deviation results in a failure or in a bad operation of customer’s equipment

•Natural phenomena, such as lightning are the most frequent cause of power quality problems.

• Switching phenomena resulting in oscillatory transients in the electrical supply

•Short-term voltage drops (sags) can trip electrical drives or more sensitive equipment, leading to costly interruptions of production

POWER QUALITY IN POWER DISTRIBUTION SYSTEMS

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AMIT KUMAR # EE200118062 [5/12]

There are two approaches • LOAD CONDITIONING - ensures that the equipment is less sensitive to

power disturbances, allowing the operation even under significant voltage distortion

• INSTALL LINE CONDITIONING SYSTEMS -suppress or counteracts the power system disturbances

A flexible and versatile solution to voltage quality problems is also offered by active power filters

SOLUTIONS TO POWER QUALITY PROBLEMS

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AMIT KUMAR # EE200118062 6[2/12]

TWO TYPES:-

1.SERIES ACTIVE POWER FILTER- operates as a controllable voltage source

2.SHUNT ACTIVE POWER FILTER-operate as a controllable current source

Both schemes are implemented preferable with voltage source PWM inverters, with a dc bus having a reactive element such as a capacitor.

ACTIVE POWER FILTERS

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AMIT KUMAR # EE200118062 [7/12]

SERIES ACTIVE POWER FILTERS

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AMIT KUMAR # EE200118062 [8/12]

SHUNT ACTIVE POWER FILTERS

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AMIT KUMAR # EE200118062 [9/12]

FACTS are designed to :

1.attaining an increase of power transmission capacity at optimum conditions, i.e. at maximum availability, minimum transmission losses .

2. Improving or safeguarding of power quality in transmission and distribution

FACTS offer remedy , by enabling confinement or neutralizing of electrical disturbances such as:-

• voltage sags • fluctuations• harmonic distortion• phase unbalance

FACTS IS THE TERMINOLOGY USED IN THE INDUSTRY

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AMIT KUMAR # EE200118062 [10/12]

The Different FACT Devices are:

• SVC (Static Var Compensators)

• TCSC(Thyristor-Controlled Series Capacitors)

• STATCOM

• PST (Phase-shifting Transformers),

• IPC (Interphase Power Controllers)

• UPFC (Universal Power Flow Controllers)

• DVR (Dynamic Voltage Restorers).

FACT DEVICES

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AMIT KUMAR # EE200118062 [11/12]

Current-limiting fuses is used to provide high-speed protection of low voltage and medium-voltage power systems.

CURRENT-LIMITING FUSES IMPROVE POWER QUALITY

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AMIT KUMAR # EE200118062 [12/12]

Current-limiting fuses provide protection against disruptive heating and electromagnetic effects,but also make an important contribution to the improvement of power quality.

FACTS solutions will be particularly justifiable in applications requiring one or more of the following qualities:

-Rapid dynamic response-Ability for frequent variations in output-Smoothly adjustable output.

CONCLUSION

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!! THANK YOU !!