The response of the system magnifies one or more harmonics to a greater degree than can be tolerated. When a problem occurs, the basic options for controlling harmonics are: 1. Reduce the harmonic currents produced by the load. 2. Add filters to either siphon the harmonic currents off the system, block the currents from entering the system, or supply the [...]
The strategies for mitigating harmonic distortion problems differ somewhat by location. The following techniques are ways for controlling harmonic distortion on both the utility distribution feeder and end-user power system. Control Harmonic Distortion on Utility Distribution Feeders: The X/R ratio of a utility distribution feeder is generally low. Therefore, the magnification of harmonics by resonance with feeder banks is usually [...]
Harmonic studies play an important role in characterizing and understanding the extent of harmonic problems. Harmonic studies are often performed when: 1. Finding a solution to an existing harmonic problem 2. Installing large capacitor banks on utility distribution systems or industrial power systems 3. Installing large nonlinear devices or loads 4. Designing a harmonic filter 5. Converting a power factor [...]
The following points highlight the four main methods used for controlling harmonic distortion in power system. The methods are: 1. Constant Frequency Control 2. Constant Tolerance Band Control 3. Variable Tolerance Band Control 4. Discontinuous Current Control. Method # 1. Constant Frequency Control: A usage of frequency controlled drives with AC motors (like asynchronous or synchronous) increased in last few [...]
There are a number of devices available to control harmonic distortion. They can be as simple as a capacitor bank or a line reactor, or as complex as an active filter. A simple mitigation action such as adding, resizing, or relocating a shunt capacitor bank can effectively modify an unfavorable system frequency response, and thus bring the harmonic distortion to [...]