The static unit is for non industrial applications. There are other factors to considered when deciding on a Frequency Converter. One factor is if you need the converter to also maintain power output when the utility is no longer available. If the Frequency Converter also needs to clean up a non stable input frequency like accepting a poor frequency range on the input and produce a stable output frequency and voltage, a Dynamic Frequency Regulator should be used.
This unit allows for a very unstable utility, while producing the required output. There are several factors which will help identify which frequency conversion solution is right for your project. Skip to content. Examples of Frequency Converters:. The frequency regulator is available from 25 — kVA. Our commitment to power quality supported the development of this industrial grade product that will correct the frequency and voltage simultaneously.
This reliability coupled with the long life design gives the Series DFR a distinct advantage over all other regulators on the market today. The Rotary Frequency Converter provides the equipment with reliable power while simultaneously converting the input voltage and frequency. The RFC acts as a rotating filter protecting the critical load from transients and blowouts. Our models are available with either a synchronous or induction motor, and is offered in horizontal or vertical configurations.
A small airport decides to add helicopter service and repair center Hz Converter. Display 10 15 20 30 per page. Add to cart. Philippines to V 50 Hz e. US to V 50Hz e. Israel , V 50Hz e. Finland to V e. Filter by: Clear All. Input Phase Clear. Single Phase Three Phase. Output Phase Clear. Selected Options. Showing of results.
Recommend Articles. Sign up for ATO newsletter. Subscribe Unsubscribe. Customer service. The DC Bus The second component, known as the DC Bus shown in the center of the illustration is not seen and in all frequency converters because it does not contribute directly to variable frequency operation. But, it will always be there in high quality, general purpose frequency converters those manufactured by dedicated frequency converter manufacturers. Without getting into a lot of detail, the DC Bus uses capacitors and an inductor to filter the AC "ripple" voltage from the converted DC before it enters the inverter section.
It can also include filters which impede harmonic distortion that can feed back into the power source supplying the frequency converter. Older frequency converters and some pump specific frequency converters require separate line filters to accomplish this task.
The Inverter To the right of the illustration is the "guts" of the frequency converter. The inverter uses three sets of high speed switching transistors to create DC "pulses" that emulate all three phases of the AC sine wave. These pulses not only dictate the voltage of the wave but also its frequency. The term inverter or inversion means "reversal" and simply refers to the up and down motion of the generated wave form.
The modern frequency converter inverter uses a technique known as "Pulse Width Modulation" PWM to regulate voltage and frequency. We will cover this in more detail when we look at the output of the inverter.
Another term you have probably run across when reading frequency converter literature or advertisements is "IGBT". The transistor which replaced the vacuum tube serves two functions in our electronic world. It can act as an amplifier and increase a signal as it does in a radio or stereo or, it can act as a switch and simply turn a signal on and off. The IGBT is simply a modern version that provides higher switching speeds — Hz and reduced heat generation.
The higher switching speed results in increased accuracy of AC wave emulation and reduced audible motor noise. A reduction in generated heat means smaller heat sinks and thus a smaller frequency converter footprint. Inverter Output The illustration to the right shows the wave form generated by the inverter of a PWM frequency converter compared with that of a true AC sine wave.
The inverter output consists of a series of rectangular pulses with a fixed height and adjustable width. In this particular case there are three sets of pulses -- a wide set in the middle and a narrow set at the beginning and end of both the positive and negative portions of the AC cycle. The sum of the areas of the pulses equals the effective voltage of a true AC wave we will discuss effective voltage in a few minutes.
If you were to chop off the portions of the pulses above or below the true AC wave and use them to fill in the blank spaces under the curve, you would find that they match almost perfectly.
It is in this manner that a frequency converter controls the voltage going to the motor. The sum of the width of the pulses and the blank spaces between them determines the frequency of the wave hence PWM or pulse width modulation seen by the motor. If the pulse was continuous i. Depending upon the desired voltage and frequency, the frequency converter will vary the height and width of the pulse and the width of the blank spaces in between. Although the internals that accomplish this are relatively complex, the result is elegantly simple!
After all, doesn't it take an alternating current to "induce" a current and its corresponding magnetic field in the motor's rotor? Well, AC causes induction naturally because it is continuously changing direction. DC, on the other hand, does not because it is normally motionless once a circuit is activated. But, DC can induce a current if it is switched on and off. For those of you old enough to remember, automobile ignition systems prior to the advent of the solid state ignition used to have a set of points in the distributor.
The purpose of the points was to "pulse" power from the battery into the coil a transformer. This induced a charge in the coil which then increased the voltage to a level that would allow the spark plugs to fire. The wide DC pulses seen in the previous illustration are actually made up of hundreds of individual pulses and, it is this on and off motion of the inverter output that allows induction via DC to occur. Fortunately, for us, all of its complexities have been explained and all we have to do is follow the rules those before us have laid out.
One of the attributes that makes AC complex is that it changes voltage continuously, going from zero to some maximum positive voltage, then back to zero, then to some maximum negative voltage, and then back to zero again.
How is one to determine the actual voltage applied to a circuit?
0コメント