Pengantar Teknik. Elektro. Kuliah 2 : Basic Electrical. Quantities. Page 2. Why
Are There Three. Conductors in Power. Transmissions Lines? ○ Most AC power
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Pengantar Teknik Elektro Kuliah 2 : Basic Electrical Quantities
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Why Are There Three Conductors in Power Transmissions Lines? z
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Most AC power transmission systems have three conductors. The voltage on each phase (referenced with respect to earth ground) is a sinusoid with a phase difference of 120° from the voltages in the other two phases.
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Three Phase z
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A three conductor transmission system is called a three-phase system. The power delivered by a three phase system (assuming a balanced load) is constant, even though the voltages in each phase vary sinusoidally. Three phase systems are more efficient than single systems due to reduced power losses.
Topics z
Introduction (1 session)
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Basic Electrical Quantities (1 session)
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Circuit Analysis (2 sessions) Introduction to Electromagnetism (1 session) Introduction to Electronics (1 session) Introduction to Digital Logic Circuits (1 session) Introduction to Digital Information (1 session) Introduction to Computer (1 session) Introduction to Telecommunication (1 session) Introduction to Control (1 session) Introduction to Power Systems (1 session) Introduction to Photonics (1 session) Review (1 session)
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Basic Concepts
System of Units
System of Units
More Units
Charge and Current
Basic Quantities z
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Basic quantities are voltage, current, and power. The sign convention is important in computing power supplied by or dissipated by a circuit element. Circuit elements can be active or passive; active elements are called sources.
Current
Types of Current
AC versus DC z
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AC is alternating current AC quantities always vary sinusoidally in time Usually, we will know the frequency and solve for the amplitude and phase.
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DC is direct current DC quantities are always constant in time. DC can not be directly transformed to lower or higher voltages.
Current Range
Voltage
Voltage Range
Representation
Example
Sign Convention
Power
Passive Sign Convention
Positive Power
Negative Power
Example
Energy
Example 10A Power plant
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+ 220V -
Which circuit element is supplying power? Which is dissipating power? How much is supplied/dissipated?
