To compete with the same applications with induction or PM machines with lower pole numbers, axial gap topologies generally require higher carrier frequencies in the variable speed drive that feed. This is to minimize ripple in the current waveforms and the resulting torque ripple at the shaft. The VSD drive size tends to be larger to accommodate the switching losses at the higher PWM carrier frequencies.
Before only servo drive used to run by feedback given by motor but now a days we can also use variable speed drive while taking feedback from motor both is used for control position, velocity and save power, but servo drive we used to control by plc according to what we write the program but variable speed drive used to control by plc program written in it and we can't modified more vsd plc program but we can make any program for servo drive while using plc.
Dithering the switching frequency of a SMPS (SSFD) introduces sideband energy that by the conservation of energy must result in a reduction in harmonic-peaks. There are two important characteristics of a frequency-modulated waveform bandwidth rule.
In a loop circuit in which the only component is a simple resistor, that resistor is the only thing in the loop that actually "resists" current flow. Apply a DC voltage to a loop without that resistance and current quickly rises...not to theoretical infinity...but until the wire melts or breaks..because the wire (not a perfect conductor) is a resistor itself.
In the days before networked motors, all inputs were accounted for in the Input list and all outputs were accounted for in the Output list. The IO count was then evaluated to help determine the complexity of a system. IO counts directly impacted many various costs in the project such as cost of hardware, cost of wiring, and the cost of installation. The complexity of the system was used to estimate how much engineering time would be required for the project.
Here I have very basic questions which I couldn't get when I searched in internet or in books. I am very new to my profession not aware of these things which I often face in my work. Please spend some time for answering my questions or showing me a way by referring some good material or books.
Variable frequency technology is a new drive technology which adopts advanced electronic technique, computer control technique and communication technique. It goes ahead of any other speed adjusting methods. Variable speed drive is bound to be widely used in more and more plants in future.
Advancements in industrial Ethernet switching technology have greatly improved the reliability in Ethernet communication. With the automation industry rapidly transitioning to Ethernet as a communication standard, it is vital that variable speed drive systems do the same. Products now are helping to lead this transition by providing an Ethernet process controller for new and existing variable speed drive systems.
say there is a permanent fault on overhead transmission line, the distance / line differential protection should operate and trip respect circuit breaker (CB) which is feeding the fault. This protection relay will initiate a 2 stage breaker failure (BF) relay too.
We all know that a cable is sized by:
1.- Current carrying capacity (with all installation adjusting factors)
2.- Voltage drop
3.- Starting voltage drop (in case of motors)
4.- Short circuit
1.- Current carrying capacity (with all installation adjusting factors)
2.- Voltage drop
3.- Starting voltage drop (in case of motors)
4.- Short circuit
A lot will depend on the final application. In the murky, oily world of motor and drives there is no need to have high frequency switching. Due to this there is not the need to use fast devices such as MOSFETs.
Variable speed drives have come a long way in the past 20 years, from being a dumb component to intelligent process controller. Following are the main points to consider:
VSD blog: A deep observation of automation control industry, especially in AC motor variable speed drive for industrial motor controls. Hot Tags
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