In a three-phase power system, the harmonics of one phase have a rotational and phase angle relationship with the harmonics of the other phases. In power system studies involving harmonics, this relationship is important. In a balanced three-phase electrical system, the voltages and currents have a positional relationship as shown in Fig. 4.6. The three […]

# Tag Archives | Power System

## Effect of Harmonics on Power System Devices | Electrical Engineering

The topic of harmonics is interesting because of the harmful effects they have on power system devices. What makes harmonics so insidious is that very often the effects of harmonics are not known until failure occurs. Insight into how harmonics can interact within a power system and how they can affect power system components is […]

## Top 3 Generators of Harmonic Currents | Electrical Engineering

Many of the loads installed in present-day power systems are harmonic current generators. Combined with the impedance of the electrical system, the loads also produce harmonic voltages. The nonlinear loads may therefore be viewed as both harmonic current generators and harmonic voltage generators. Prior to the 1970s, speed control of AC motors was primarily achieved […]

## Guidelines on Harmonic Currents for Individual Customers | Electricity

The primary limit on individual customers is the amount of harmonic current that they can inject into the utility network. The current limits are based upon the size of the consumer relative to the size of the supply. Larger customers are restricted more than smaller customers. The relative size of the load with respect to […]

## Mitigation of Harmonic Frequency Current | Electrical Engineering

In this article we will discuss about:- 1. Equipment Design for Harmonic Current Mitigation 2. Harmonic Current Cancellation 3. Harmonic Filters. Equipment Design: The use of electronic power devices is steadily increasing. It is estimated that more than 70% of the loading of a facility by year 2010 will be due to nonlinear loads, thus […]

## Measuring Flicker in Voltage: 3 Techniques | Electrical Engineering

The following points highlight the three main techniques used for measuring flicker in voltage during electricity supply. The techniques are: 1. RMS Strip Charts 2. Fast Fourier Transform 3. Flicker Meters. Technique # 1. RMS Strip Charts: Historically, flicker has been measured using rms meters, load duty cycle, and a flicker curve. If sudden rms […]

## Principles for Controlling Harmonics | Electrical Engineering

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 […]

## Harmonic Distortions in Power Supply System | Electrical Engineering

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 […]

## Where to Control Harmonic Distortion? | Power System

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 […]

## Harmonic Studies: Procedure and Tools | Electrical Engineering

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 […]