vfds

When it comes to controlling the speed and performance of electric motors, Frequency Converters and Variable Frequency Drives (VFDs) are two commonly discussed technologies. While these terms are often used interchangeably, they have distinct characteristics, applications, and advantages. In this blog, we'll explore the key differences between a frequency converter and a VFD to help you understand when and how to use each device.

What is a Frequency Converter?

A frequency co ...

In the realm of industrial automation, Variable Frequency Drives (VFDs) have emerged as a pivotal technology, revolutionizing the way motors are controlled. This article aims to explore the intrinsic advantages of VFDs, providing a detailed insight into why they are the preferred choice in the industrial sector, backed by real-world applications and data.

What are VFDs?

A Variable Frequency Drive, commonly referred to as a VFD, is a sophisticated electronic device designed t ...

Frequency converters play a vital role in the wave of industrial automation, and GoHz, as a leader in the industry, not only provides high-quality frequency converters, but also introduces more advanced Variable Frequency Drives (VFDs) to meet the needs of different industrial applications. needs of different industrial applications. This blog will explain the specific applications of frequency converters in some of the key industries.

Basic Information of Frequency Converters

Variable Frequency Drive (VFD), generally it's using for controlling speeds of three phase induction motors. In technical it's possible to use a variable frequency drive for 1-phase motor speed controls, but we have to mention, control single phase motor speed by a variable frequency drive may cause overheat of the AC motor, as well as the service life. It's recommended to upgrade the motor to 3-phase AC motor, which you can also connect the 3-phase motor to single phase power supply by using ...

Variable Frequency Drive (VFD, also call variable speed drive, adjustable speed drive) converts AC to DC and then from the DC creates an output voltage at an adjustable frequency to run the induction motor at variable speed from 0 to 50Hz/60Hz. The voltage generally varies from 0 to rated input voltage as the speed goes from 0 to 50Hz/60Hz. VFD also can go above 60 Hz up to 400 Hz, but the torque falls off as the speed increases. The biggest advantage that a VFD has is the ability to save mon ...

Induction motors produce torque based on the DIFFERENCE between the rotor speed and synchronous speed. The applied line voltage produces a rotating magnetic field whose lines of flux are cut by the squirrel cage rotor windings. When those windings cut flux lines, a current is induced that produces a rotating magnetic field. Thus you have 2 magnetic fields attracting each other. If the induction motor is sped up by an overhauling load, the difference can fall to 0 and thus no current in the ro ...

Depending on your local electrical code, if you need a grounded (earthed) system, you can use a 400V-Delta to 208/120V WYE transformer to feed a variable frequency drive (VFD), and then set it a 60Hz to supply 208V 60Hz to the motor. Although I do not normally recommend it, if it is appropriate for you to run the system ungrounded (unearthed), then you can feed the VFD with through a 400V-Delta to 230V-Delta transformer and then supply the motor with 230V 60Hz power from the VFD. (As with mos ...

The torque speed curves are completely different between an induction motor and slip ring motor. You need to understand the differences. If you have selected your slip ring motor to limit starting currents you can short out the slip rings and run your motor but the starting torque is reduced unless you use some features on the VFD to boost starting torque.

If you are using it as torque control on a crane then ...

Variable frequency drives should be protected by fuses. Why? Because the VFD itself has all the protection you require for your motor so the only item you are protecting is the Rectifier and DC bus. Then you will find it is actually really impossible to protect it as when it has a fault it is generally catastrophic and all you wish to do is to remove the faulty VFD from the network to enable the rest to continue. This must be as fast as possible to limit the damage and MCBs don’t really ...

There are a couple of thoughts on this. You could connect a PLC to a VFD using a communication protocol like Ethernet IP or Modbus to name a few or using a collection of analog and digital signals. I prefer a combination of the two ideas. For command and control signals I use analog or digital signals. For all other data I use a communication protocol. The reason is that any decent technician can troubleshoot an analog or digital signal but troubleshooting a communication protocol takes a ver ...

Operating on a VFD means there is a LOT of high-frequency distortion of the waveform, leading to imbalance in the magnetic circuit - which in turn leads to the development of shaft potential. If the shaft is higher potential than the ground plane, then current will flow - directly across the bearing, usually. So get a good grounding method (actual brushes riding on the shaft are by far the best over the long haul, in my experience). How do you know it's happening? The failure mode is scoring, ...

The most correct term - according to IEEE and IEC - is ASD (Adjustable Speed Drive). This refers to the electronic equipment used to regulate the operating speed of the motor and driven equipment by controlling the frequency and voltage applied to the motor.

NOTE that other terms in common use include (but are not limited to): VSD (Variable Speed Drive), AFD (Adjustable Frequency Drive), and VFD (Variable Frequency Drive), they are referring to the same motor drives, just different ...

The normal frequency in Australia is 50 Hz and a client of mine runs his compressor motors up to 60 Hz which gives him greater output. But he only gets away with it because the machines are from the United States and are rated to operate at 60 Hz. Be careful because there could be a significant increase in power at the higher speeds in 60Hz.

Before you attempt to do this verify with the compressor motor manufacturer if you motor is VFD rat ...

A VFD-driven general purpose motor can overheat if it is run too slowly. (Motors can get hot if they’re run slower than their rated speed.) Since most general purpose motors cool themselves with shaft-mounted fans, slow speeds mean less cooling. If the motor overheats, bearing and insulation life will be reduced. Therefore there are minimum speed requirements for all motors.

General purpose motors can be run with VFDs in many applications; however inverter-duty motors are de ...

To cope with the effect of the power electronics and the pulse thereof, it is usual to wind stator with specially varnished wire from supplier. This is often referred as triple coated as opposed to double coated (Standard offering). Don't be confused by number of coatings terminology. The wire has multiple coats applied. The term double and triple are generic to the industry. In effect the number of pin holes per m length of wire is reduced and the insulation (Enamel coating) on the wire has ...

Case: A fan motor of 315kw running on VFD. Its operating speed is 795 rpm but its winding temperature gets heated like R phase temperature is 126.3 Y phase temperature is 125 and B phase temperature is 120. The motor is surrounded by cooling fans still temperature gets raised. Is there any alternative or have to change the motor to 400kw?

Heating effect can be caused by improper load match of the motor and mechanical VFD. Look at the temperature rise of the motor on the na ...

All driven loads have some relationship between power and speed. As a general statement - more power is consumed at higher speeds.

Most motors are designed to operate at a constant speed and provide a constant output; however, modern technology requires different speeds in many applications where electric motors are used. A variable frequency drive (VFD) is a device that regulates the speed and rotational force, or output torque of mechanical equipment. Effects of applying VFDs are ...

Capacitors inside the variable frequency drive (VFD) is mainly used to maintain the DC voltage, this is common thing all are well known about this, but power factor is mainly improved due to the cosine angle between voltage and current are mostly near to each other, however the inductive load produces the reactive power which will directly affect the wave form of input of VFD sine wave when we used additional filter ca ...

This question is for developer or those who are master in PID control & would like to save cost in certain application. For speed control, it's no longer used PID methodology by programmer. Now PID control is integrated into variable frequency drive control. For example, if you want to stabilize the speed at 1500rpm, no matter load changed, via an advanced VFD, PID is itself tuning to keep it stable at 1500rpm.

I like the auto tuning function on rotating equipment that has hig ...

Q: I have a conveyor application. There we have a Motor connected to Gear Box. Motor is driven by a variable frequency drive (VFD). Details are as follows
Motor Power - 2.2 kW, 415V, 50 Hz, 1460RPM
VFD - 2.2 kW
Gear Box - Ratio = 58.25, RPM - 25 Rev/Min ,

According to the Above details, gear box output is 25 Rev/Min When the Motor Runs at 50 Hz at 1460 RPM. But I need to increase the Gear box output (Conveyor Speed) from 25 RPM to 53 RPM. So, as a t ...