Electrical Power Systems Technology

50 Electrical Power Systems Technology looking at the power triangle shown in Figure 2-19. There are two compo- nents that affec ...

Power System Fundamentals 51 opposite side sine θ = —————— hypotenuse Since this is true, the phase angle can be expressed as: r ...

52 Electrical Power Systems Technology is the power factor of a circuit; therefore, the power factor is equal to the co- sine of ...

Power System Fundamentals 53 voltage diagram is shown in Figure 2-21. In Figure 2-20, poles A’, B’, and C’ represent the beginni ...

54 Electrical Power Systems Technology Sample Problem: Given: phase voltage = 120 volts for a three-phase wye system. Find: line ...

Power System Fundamentals 55 Figure 2-22. The two methods of connecting three-phase stator coils together: (A) The wye (or star) ...

56 Electrical Power Systems Technology The total power (PT) developed by all three phases of a three-phase system is expressed a ...

Power System Fundamentals 57 where: VL is the line voltage in volts, IL is the line current in amperes, VP is the phase voltage ...

58 Electrical Power Systems Technology The power developed in an inductive circuit is dependent upon the power factor (pf) of th ...

59 Chapter 3 Power Measurement Equipment Chapter 3 provides an overview of the types of equipment used to measure electrical pow ...

60 Electrical Power Systems Technology True Power Apparent Power Power Factor Three-Phase Power Analyzer Power Factor Meter Powe ...

Power Measurement Equipment 61 Many meters employ an analog movement called the d’Arsonval, or moving-coil, type. The basic oper ...

62 Electrical Power Systems Technology multifunction meters. The basic meter movement may be modified so that it will measure al ...

Power Measurement Equipment 63 standard resistance (Rs) is marked on the meter, so that the value of the un- known resistance (R ...

64 Electrical Power Systems Technology cal-control applications as well. Memory and storage type instruments are available for u ...

Power Measurement Equipment 65 Chart-recording Instruments The types of instruments discussed previously are used when no perman ...

66 Electrical Power Systems Technology several basic principles. The user should assure that the chart roll has enough paper to ...

Power Measurement Equipment 67 numerical readout of the kilowatt-hours used. Study Figure 3-7 to learn to read a watt-hour meter ...

68 Electrical Power Systems Technology electrical energy that is used must pass through a watt-hour meter. The same type of syst ...

Power Measurement Equipment 69 age windings and the current windings. The field developed in the volt- age windings causes a cur ...