2016 China International Conference on Electricity Distribution
... development of semiconductor devices and power electronic technology, a new type of intelligent substation equipment is coming into the world—High-frequency Transformer (HFT) or Power electronic transformer (PET), resolving most of the problems and drawbacks that traditional transformer has (e.g. la ...
... development of semiconductor devices and power electronic technology, a new type of intelligent substation equipment is coming into the world—High-frequency Transformer (HFT) or Power electronic transformer (PET), resolving most of the problems and drawbacks that traditional transformer has (e.g. la ...
Bharat Heavy Electrical Limited model Exam Paper
... Which of the following statement is true about two wattmeter method for power measurement in three phase current ?a.) power can be measured using two wattmeter method only for star connected three phase circuits.b.) when two meter show indentical readings, in the power factor is 0.5. c.) when powe ...
... Which of the following statement is true about two wattmeter method for power measurement in three phase current ?a.) power can be measured using two wattmeter method only for star connected three phase circuits.b.) when two meter show indentical readings, in the power factor is 0.5. c.) when powe ...
angle modulation
... • One of the properties of a sinusoidal wave is its phase, the offset from a reference time at which the sine wave begins. • We use the term phase shift to characterize such changes. • If phase changes after cycle k, the next sinusoidal wave will start slightly later than the time at which cycle k c ...
... • One of the properties of a sinusoidal wave is its phase, the offset from a reference time at which the sine wave begins. • We use the term phase shift to characterize such changes. • If phase changes after cycle k, the next sinusoidal wave will start slightly later than the time at which cycle k c ...
Fairchild PowerPoint Presentation Template
... – CCM operation at high frequency for size reduction • High Line @ 85kHz for efficiency & EMI • Low Line @ 140kHz for transformer size reduction – 85k/140kHz fixed frequency for easier dealing CMN interference to touch panel – CCM operation to boost efficiency – SD for OTP to save external OTP circu ...
... – CCM operation at high frequency for size reduction • High Line @ 85kHz for efficiency & EMI • Low Line @ 140kHz for transformer size reduction – 85k/140kHz fixed frequency for easier dealing CMN interference to touch panel – CCM operation to boost efficiency – SD for OTP to save external OTP circu ...
Utility frequency
The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the frequency of the oscillations of alternating current (AC) in an electric power grid transmitted from a power plant to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains power around the world.During the development of commercial electric power systems in the late 19th and early 20th centuries, many different frequencies (and voltages) had been used. Large investment in equipment at one frequency made standardization a slow process. However, as of the turn of the 21st century, places that now use the 50 Hz frequency tend to use 220–240 V, and those that now use 60 Hz tend to use 100–127 V. Both frequencies coexist today (Japan uses both) with no great technical reason to prefer one over the other and no apparent desire for complete worldwide standardization.Unless specified by the manufacturer to operate on both 50 and 60 Hz, appliances may not operate efficiently or even safely if used on anything other than the intended frequency.