Harmonic currents produced by nonlinear loads can interact adversely with the utility supply system. The interaction often gives rise to voltage and current harmonic distortion observed in many places in the system. Therefore, to limit both voltage and current harmonic distortion, IEEE Standard 519-19922 proposes to limit harmonic current injection from end users so that harmonic voltage levels on 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 [...]
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 [...]