Harmonics are therefore disturbances and they entail costs that are not always easy to detect and assess. These costs can be classified into two types:
- Technical costs
- Economic costs
Technical costs are those that entail a loss of performance in the installation, such as:
- Loss of capacity in energy distribution lines
- Transformer overload
- Conductor overload
- Transformer derating
- Joule effect losses in lines and machinery
- Magnetic losses in electrical machinery
- Increased leakage
Typically, technical costs lead to economic costs, which is why controlling technical costs is so important.
Economic costs are those that can be quantified monetarily, although sometimes they are not easy to calculate. They may be visible or hidden:
- Higher electrical consumption
- Electrical consumption peaks
- Surcharge or payment for reactive energy on the electric bill
- Distribution losses
- Power and energy losses (due to the Joule effect or magnetic losses)
- Expansion of installations
- Production process downtime
These costs depend on the type of installation and the connected loads.
How can we find out if we are experiencing these harmonic disturbances? How can we avoid them or limit their negative impact? We will learn how in the following sections.