Tag: Power systems
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The Effects of Low Power Factor on Electrical Equipment
The cosine of the angle between voltage and current in an AC circuit is referred to as the power factor. In a typical AC circuit, there is a phase difference Φ between the voltage and current. The term cos Φ is termed to as the power factor of the circuit; if the current is inductive,…
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Synchronous Compensators, What is their Purpose in Power Systems?
When designing a transmission or distribution system, the engineer must take into account not only the power requirement of the loads, but also the fact that they consume reactive power and to the same degree key, that networks include inductive and capacitive components which themselves absorb or generate reactive power. Power is generated and consumed…
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What is the Function of Unified Power Flow Controller?
In a number of cases, it may be possible to increase the grid’s capacity through enhanced control of the active and reactive power flow in the transmission network independently of busbar voltage. The Unified Power Flow Controller (UPFC) provides the reactive shunt compensation, active and reactive series compensation and phase shifting. It is thus capable…
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The Connection of Green Energy Generation Plants to Power Systems: Key Factors to Consider
To prevent negative effects on the operation of the power system and equipment, a number of factors must be considered when connecting green energy generation plants to these systems. The following should be factored in: With the increased development of green energy generation plants, special aspects need to be considered such as the use of…
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Causes of Power System Disturbances & Corrective Measures
Even though most protective system designs are built around individual components, system-wide disturbances in power systems are rather a frequent occurrence and a challenging issue for electric utility companies. When major disturbances occur in power systems, it is imperative to implement coordinated protection and control actions to stop the system degradation, restore the normal state…
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Sources of Power Quality Problems
Power quality may be affected by a number of issues. Our discussion in this article focuses on various devices and events that lead to problems in power quality. The common sources of power quality problems include: Power Electronic Devices Power electronic devices cause power quality disturbances and they are also susceptible to them. Variable speed…
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Common Terms Used When Describing Power Quality Problems
Power quality has become an important issue to electricity consumers at all levels of consumption. This has especially been intensified by the common use of sensitive equipment and non-linear loads in both industrial and the domestic environs. In this article we look at some of the common terms typically used when describing power quality problems.…
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Magneto-Optic Current Sensors for High Voltage, High Power Transmission Lines
One of the key challenges in measuring the electrical current in high voltage, high power transmission lines, is that of measurement circuit isolation. One way of measuring heavy 60 Hz currents in a conductor is through the use of a current transformer. A current transformer typically consists of a number of turns of wire wound…
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AC to AC Power Converters with Intermediate DC Link: Types, Features & Applications
This category of AC drives that is often referred to as “Variable Frequency Inverters” is one of the most extensively used drives in industrial motor control applications. Generally, the concept of these inverter drives can be summarized into three parts: We have two main classifications of these AC drives that are based on the aforementioned…
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DC to DC Power Converters: Function, Types, Operation & Applications
DC to DC power converters also referred to as choppers provide the means to change one DC voltage to another. Normally the conversion is to a lower voltage however, we also have step-up converters. DC to DC power converters are fed from a DC supply usually comprising an uncontrolled AC to DC converter or alternatively…