Author: John Mulindi
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Basic Features of Numerical Control
Numerical control is a form of digital control that is employed on machine tools such as milling machines and lathes to automatically cut and shape the work-piece without a human operator. Each machine has its own set of axes or … Read more
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How to Size a Control Valve
Pneumatic control valve Control valve sizing refers to the procedure determining the correct size of a valve body. A valve sizing equation for incompressible fluids is given by: Which is the same as: Where Cv is the valve flow … Read more
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Process Control System Design for a Distillation Unit
The aim of a typical control system is to force a given set of process variables to act in some desired and prescribed way by either fulfilling some requirements of the time or frequency domain or achieving the best performances … Read more
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Limit Switches vs. Proximity Sensors
An object can be used to activate a switch directly, producing an ON or OFF signal to indicate the presence of that particular object, alternatively we can use the presence of a nearby object to activate a sensor giving a … Read more
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Three-Position Control System: Operation & Typical Application
A three-position control is akin to two-point control, except that in this case, the controller has three states, such as forward-off-reverse, (or up-off-down, hot-off-cold, etc.). This is a control strategy that is usually applied in a system that has … Read more
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What are Flexible Alternating Current Transmission Systems (FACTS) Controllers?
Flexible AC Transmission Systems (FACTS) can be described as AC transmission systems incorporating power electronic-based controllers and other static controllers to boost controllability and increase power transfer capability. FACTS equipment that provides control of one or more of the parameters … Read more
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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: The rated power of the … Read more
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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 … Read more
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Standard Process Signals for Industrial Instrumentation
Industrial measurement and control processes employ standard process signals that are used throughout all the industries. For instance, one of the most popular forms of signal transmission in modern industrial instrumentation systems is the 4-20 mA DC standard. The … Read more
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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 … Read more