Electrical Power Systems Technology

30 Electrical Power Systems Technology OVERVIEW OF ALTERNATING CURRENT (AC) CIRCUITS The following discussion provides an overvi ...

Power System Fundamentals 31 Figure 2-9. Problem that shows maximum power transfer ...

32 Electrical Power Systems Technology Resistive AC Circuits The simplest type of AC electrical circuit is a resistive circuit, ...

Power System Fundamentals 33 Sample Problem: Energy Stored in an Inductor A coil stores energy in its magnetic field because of ...

34 Electrical Power Systems Technology Given: a 10-henry coil has 5.8 amperes of current flowing through it. Find: the amount of ...

Power System Fundamentals 35 during the intervals from 0° to 30° and from 180° to 210° does negative power result. The remainder ...

36 Electrical Power Systems Technology Any inductive circuit exhibits the property of inductance (L), which is the opposition to ...

Power System Fundamentals 37 measurement for inductance is the henry (H). A circuit has a 1-henry in- ductance if a current chan ...

38 Electrical Power Systems Technology Figure 2-13. Capacitive circuit: (A) Circuit diagram; (B) Waveforms; (C) Vector represent ...

Power System Fundamentals 39 proportional to the distance between the plates. The unit of capacitance is the farad (F). A capaci ...

40 Electrical Power Systems Technology in the purely inductive circuit. As shown in Figure 2-13B, the positive and negative powe ...

Power System Fundamentals 41 resent voltage or current values. An understanding of vector diagrams (sometimes caned phasor diagr ...

42 Electrical Power Systems Technology clockwise direction, indicating a lagging condition. A leading condition is shown for the ...

Power System Fundamentals 43 Use of Vectors for Parallel AC Circuits ector V representation is also useful for parallel AC circu ...

44 Electrical Power Systems Technology Sample Problem: Given: resistive current = 125 amperes, and reactive current = 65 am- per ...

Power System Fundamentals 45 Sample Problem: Given: an AC circuit has the following component values: R = 100, L = 1 H, C = 10μF ...

46 Electrical Power Systems Technology Z = R^2 + XL– XC 2 100 (^2) + 376.8 – 265.4 2 10,000Ω 12,410+ Ω Z = 149.7 Ω This formula ...

Power System Fundamentals 47 Figure 2-17. Impedance in series AC circuits: (A) Circuit diagram; (B) Vector dia-gram; (C) Impedan ...

48 Electrical Power Systems Technology POWER RELATIONSHIPS IN AC CIRCUITS An understanding of basic power relationships in AC ci ...

Power System Fundamentals 49 measured with a wattmeter. This actual power is referred to as true power. Ordinarily, it is desira ...