Unit IV: Electrical Power Conversion Systems

Home | Articles | Forum | Glossary | Books

AMAZON multi-meters discounts AMAZON oscilloscope discounts

One of the most important aspects of electrical power systems is the conversion of electrical power into some other form of energy. Electrical power is ordinarily converted into light, heat, or mechanical power. The power is converted using either resistive, inductive, or capacitive circuits.

The fundamental characteristics of electrical power conversion systems are discussed in Section 11.

The basic types of electrical power conversion systems are studied further in the remaining Sections. Heating systems are discussed in Section 12. Those systems that convert electrical energy into heat energy use three methods, incorporating resistive, inductive, and capacitive circuits. Basic welding method systems are also included in this Section, since they are a unique type of electrical load. Section 13 deals with the conversion of electrical energy into light energy. Lighting systems include incandescent, fluorescent, and vapor lighting systems. The systems that convert electrical energy into mechanical energy are discussed in Section 15. The major mechanical energy conversion takes place in electric motors.

Both direct current (DC) and alternating current (AC) motors are studied in that Section.

Figure IV shows the electrical power systems model used in this guide, and the major topics of Unit IV: Electrical Power Conversion Systems.


Figure IV. Electrical power systems model

UNIT OBJECTIVES

Upon completion of this unit, you should be able to:

1. Define the term "electrical load."

2. List the types and classifications of electrical loads.

3. Explain the differences between resistive, inductive, and capacitive circuits.

4. Calculate load (demand) factor and power factor.

5. Describe power factor correction, using static capacitors or synchronous capacitors.

6. Define true power, apparent power, and reactive power in AC circuits.

7. Calculate power per phase and total power for balanced or unbalanced three-phase loads.

8. Explain the differences between resistive, inductive, and capacitive electric loads.

9. Describe electric resistive and arc-welding systems as electrical loads.

10. Describe electric heating systems and these associated terms:

  • BTU
  • Design Temperature Difference
  • Degree Days
  • Thermal Resistance (R)
  • Coefficient of Heat Transfer (U)
  • Watts of Heat (W)

11. Describe heat pumps and air conditioning systems.

12. Describe the characteristics of light.

13. Define the terms candlepower, lumen, and footcandle as they relate to light.

14. Describe types of street lighting systems.

15. Explain the characteristics of incandescent, fluorescent, and vapor lighting.

16. Describe branch circuits used for controlling electrical lights from one, two, or three locations.

17. Calculate the minimum number of branch circuits and total power requirements for lighting circuits in buildings.

18. Describe the following factors that affect lighting fixture design: Luminaire

  • Coefficient of Utilization (CU)
  • Room Ratio
  • Depreciation Factor (DF)

19. Calculate light output of a lighting system.

20. Describe the basic principles of electric motor operation.

21. Identify and describe the following types of electric motors:

  • DC Motors
  • Single-Phase AC Motors
  • Three-Phase AC Motors

22. Explain the operation of synchro/servo systems and DC stepping motors.

23. Calculate the following, as each relates to electric motor operation: Horsepower

  • Speed Regulation
  • Starting Current
  • Synchronous Speed
  • Slip
  • Rotor Frequency
  • Efficiency
Top of Page

PREV   Next | Guide Index | HOME