Higher frequency in Electrical Engineering
An electric power system is specified by two main important parameters including voltage and frequency. To keep the expected operating conditions and supply energy to all the users (loads) connected, it is essential for the students of best engineering college in Jaipur to control these parameters within predefined limits, to avoid unexpected disturbances that can create problems to the connected loads or even fail the systems.
The most commonly used nominal frequency (Fn) in power systems is considered as 50 Hz and 60 Hz in some countries. The reasons for this choice are dependent on technical compromises and historical situations. Generally, when the system operates in a range of frequency Fn±0.1 Hz, it is in the standard conditions, while when the frequency ranges from 47.5 to 51.5 Hz, it is known as the emergency condition or restoration condition. These values differ as per each country.
Frequency differences in a power system occur because of an imbalance between generation and load. When the frequency value of a power system reaches the emergency condition, the control strategy get started. The frequency control is classifying in three basic levels including primary, secondary and tertiary controls. Each frequency control has particular features and purposes.
60Hz means the power waveform cycles 60 times per second, and 50Hz is described as the power will cycle 50 times per second. These two basic frequencies are the primary reason for frequency conversion. Before the 1900’s there were many frequencies produced across the globe utilizing Water and Steam Turbines ranging from 16Hz to 133Hz. However, initially in 1900’s, the electric power grids get standardized on 50Hz and 60Hz AC power. The origins and actual inventors have become a topic for conversation, but it is clear that Edison, Tesla and Westinghouse were all involved.
Presently, the Electric Utilities in some countries produce power at a frequency of 60Hz. This excludes some very old and still in operation Hydro Plants that produce power with at 25HZ. Most of the other countries across the globe produce power at a frequency of 50Hz.
How frequency converter works?
To change the frequency of ac current, frequency converter goes through two stage conversion by the students of top engineering colleges in Jaipur. First it converts ac to dc, then secondly dc to ac of required frequency. Thus, frequency converter has two sets of working including the rectifier circuit converts ac to dc and then inverter circuit with thyristors/ IGCTs / IGBTs converts dc to ac with desired frequency. The shifting and changing of frequency happen in the converter stage.
If voltage conversion is required, a transformer will be included in either the ac input or output circuitry and this transformer may offer galvanic isolation between the input and output ac circuits. Also, a battery may be added to the dc circuitry to improve the converter’s ride-through of brief outages in the input power.
Why do I need a frequency conversion?
Small components such as computers and small electronics operate with switch mode power supplies. These operate at both 50HZ and 60HZ and, the only item students of electrical engineering colleges in Jaipur may need is a plug converter as 50HZ outlets are not the same as 60HZ outlets. This is because both of them operate at different frequency and does not require plugging equipment into the wrong power source or run the risk of damaging equipment and or harming yourself. You cannot put it back, once you let the smoke out of the equipment.
Specific industry
Some particular industries have unique frequency requirements based on how they supply power to their equipment. While Aviation and some Weapons systems requires 400Hz. These systems internally create 400HZ power. Thus, a ground power unit, also called a GPU produces 400HZ , if an equipment is not operating and providing the internal 400HZ. Considering this, electrical systems used on the ground required the Ground power support.
On the other hand, 400Hz is used in different airport and military radar applications. Rail utilize 25, 91.66 or 100Hz to run their signal systems while Ship yards and boat docks require frequency conversion for shore power. Therefore, a frequency converter is required by the electrical system to match the power. There are different variable frequencies needed in laboratories and testing facilities.
What are the types of frequency conversion?
For students of private engineering colleges in Jaipur, some applications are better suited for Rotary Frequency Conversion. It is also called Motor Generator Sets or Rotary Converters. While others may be more suitable for Static Frequency Conversion (also called Solid State Converters). Each type offers its benefits and shortcomings. Thus, some companies will build both types of equipment. It allows the customers to select what they need.
Experts of engineering colleges uses a generator called Rotary Frequency Converter to produce a true output sine wave at the desired frequency much like the power companies. A Static Frequency Converter further uses a double conversion process with a rectifier that changes the AC input to DC. Later, the inverter converts it back to an AC output. And lastly, wave shapes the frequency resulted in a re-created sine wave. The resulting frequency and/or voltage conversion from any type of unit is suitable for most applications. Price, serviceability, design life, size, and noise are the deciding factors when purchasing a Frequency Converter system.
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