Power Quality in Electrical System
The amount of harmonics in the power system is determined by the total harmonic distortion (THD) measurement. High harmonic distortion negatively affects the electricity distribution network and leads to overheating and premature failure of the motors. The resulting heat also disrupts the insulation structure of the cables.

• The reasons for increasing interest in power quality are listed below:
  Measurement - Low power quality affects the system measurement accuracy.
  Protection roles - affects the optimum functioning of the rollers.
  Posture - damages equipment and causes downtimes.
   

İDEAL VOLTAGE WAVE TYPE

İideal wavelength, magnitude, frequency, and waveform distortion is the size of the predetermined limits. When the ideal waveform is applied to the load, the load current will have its frequency and size depending on the impedance and characteristic of the load. Load current characteristic is called as non-linear. Non ir sininozidial current also leads to disturbances in the supply voltage, which is an indicator of low power quality.
 

 NON-LINEAR LOAD: RECTIFIER

> Devices that convert alternating current into direct current are the most common nonlinear loads in rectifiers electrical systems. These devices are available in the interior of many devices, from 100W personal computers to 10000kw adjustable speed controllers.
> Three-phase rectifiers eliminate the solid harmonics 3 and 3. 5,7,11,13 harmonics are high. In electrical systems, each current harmonic is treated separately.
> Harmonic currents and voltages may cause faulty tripping of the earth fault circuits. The measurement instrumentation can be affected by harmonics and cause the switches to open prematurely.
> High-frequency switching circuits, such as switching power supplies, power factor correction circuits, and speed drives, include high-frequency components that do not multiply the line frequency. For example, a switched-mode power supply operating at 75 kHz produces high-frequency components that are fully solid at a switching frequency of 75 kHz. These frequency components are sometimes called interharmonics to separate them from harmonics.
> Other sources of interharmonics are cycloconverters, arc furnaces. High frequency components may interfere with other nearby electronic devices (EMI). Medical electromagnetic devices are particularly sensitive to EMI because they work with low-level signals. Telephone communication may also be interrupted by EMI.
 

DESCRIPTION OF POWER QUALITY

> > Power quality is the energization and grounding required for the operation of the equipment. It is not easy to define the proper power quality because the power quality required for the refrigerator may not be sufficient for computers or sensitive electronic devices.