The quality of electrical energy is a concept that can be defined as a state of balance between the characteristics of energy consumption of the devices and the energy supply, under appropriate conditions that allow maintaining the continuity of the electrical flow, without deteriorating or generating failures the equipment components.

The emphasis on “can be defined as” is due to the fact that there is currently a debate about the term worldwide, since many organizations have given it their own interpretation according to the social variables in the consumption of electric energy. There are those who assure that to define the quality of electrical energy it is necessary to explain to the citizen at what time they have a level of quality electrical service or what the same with quality of electrical services is.

There is quality of electrical services when all the technical and administrative characteristics related to the generation; transmission and distribution of the electrical energy that is provided to the user satisfy their energy consumption needs.

However, there are four factors that affect the quality of the energy and that can be of reference to classify the variations in the limit of tolerance of load selected for the equipment:

  • Electric frequency variations: They are rare and usually occur in electrical systems powered by supply companies, especially when they are in isolated motor-generator systems.
  • Variations in electrical amplitude: They occur in different ways and time ranges. They can be short or prolonged under conditions of stable states.
  • Waveform variations: They are produced by non-linear loads called harmonic distortion.
  • Imbalance between the phases of a multi-phase system: It is caused by the operation of unequal single-phase loads. They especially affect rotary machines and three-phase rectifier circuits.

Being these fluctuating factors it is not easy at all to obtain an optimum electrical energy quality , since this will depend essentially on the energy needs of the electrical equipment, since a good quality of energy for a refrigerator may not be sufficiently Good for a washing machine and vice versa.

It is known that there are more sensitive equipment than others to variations such as digital clocks and computers. Being these the main affected ones of the deterioration of the quality of the electrical energy and generators of her in turn, since its use has increased the consumption of energy drastically.