What is a Variable Frequency Drive?

What Is a Variable Frequency Drive?

A variable frequency drive is an electric motor control device that controls the frequency and voltage supplied to a motor. VFDs accomplish this by converting DC voltage into a variable-frequency alternating current (AC) drive. They boost and regulate power before pumping it to the motor and control decelerating and braking processes.

Unlike utility power sources, which provide a fixed frequency that keeps a motor running at full speed constantly, VFDs provide flexibility by adjusting speed drive based on capacity needs.

How Does a Variable Frequency Drive Work?

VFDs operate by transferring one voltage to another and changing motor speed without losing torque or efficiency. VFDs work by leveraging four main sections:

Rectifier

The rectifier, or converter, translates AC power from the main supply to DC power. This can be done in a unidirectional or bidirectional way.

DC Bus

After converting, the power is fed to the DC link. This consists of capacitors and inductors to prevent ripples and store energy.

Inverter

Inverters receive the DC power from the link and convert it into AC power before delivering it to the motor. This equipment uses innovative modulation methods, like pulse width modulation, to control the speed of an induction motor by varying output frequency.

Control Circuit

A control circuit is a microprocessor unit that controls and configures drive settings while interfacing communication protocols. It also regulates the voltage ratio by receiving feedback from the motor.

When Should You Use a Variable Speed Control for an Electric Motor?

Knowing when to use a VFD can be challenging, and it requires a thorough assessment of your existing processes. Here are some reasons when it makes sense to utilize a VFD:

You want to precisely control the speed of your manufacturing processes.
Your operations need a smooth start and controlled acceleration to its necessary speed.
The applications your company uses are consuming too much energy, and you want to reduce costs.
You want to improve the process and quality of acceleration, flow, monitoring, speed, torque, and other elements.
Your team wants to run a motor in specialized patterns to reduce electrical stress.

What Advantages Do Variable Frequency Drives Provide?

VFDs provide adjustable speed characteristics that enable workers to run applications at specific speeds. Other advantages include:

Reduced Energy Consumption

Using utility power to run your equipment means they’re operating at full capacity when in use. This increases costs by wasting energy. VFDs offer magnitude and frequency control reducing power and delivering more energy-efficiency processes. VFD’s are especially beneficial to electric motor start up, ramping up to a desired speed vs a power-consuming hard start.

Enhanced Closed-Loop Controlled

VFDs provide accurate motor speed positioning by regularly comparing with reference speed even while experiencing changes in loading conditions and input disturbances. This allows for smoother operations and increases energy efficiency by minimizing the starting current.

Increased Production

Using a VFD allows you to increase production by implementing a tighter process control method. Operating at an efficient speed reduces mistakes and allows your team to maximize productivity.

Extended Useful Life of Equipment

Variable frequency drives increase the useful life of equipment by minimizing how often they operate at maximum speeds. This reduces the risk of breakdown and enables your staff to enhance uptime.

Want To See Examples of Our VFDs in Action?

Check out our case studies and see how our variable frequency drives have helped clients increase efficiency and reduce costs.

Our Case Studies

Variable Frequency Drives Offered by Invention House

Finding the right VFD provider is essential to getting the right equipment for your processes. Purchasing off-the-shelf motor drives may not provide the durability to withstand extreme temperatures and conditions. As a leading motor control engineering company, Invention House offers ruggedized variable frequency drives that maintain speeds during demanding jobs. Our selection includes:

Invention House offers flange-format 120-volt single-phase VFDs that efficiently control motors in OEM equipment. We understand the vital role these play in various processes and offer two chassis drives:

SPD-2230

The SPD-2230 single-phase motor drive features an aluminum flange chassis that’s conformal coated. Built to power cryogenic compressors and traditional and linear motors, it’s capable of operating in extreme temperatures. Our SPD-2230 features a connector-based input/output for rapid assembly.

SPD-500

Our SPD-500 is a single-phase drive suited for OEM and military equipment. Built to withstand extreme temperatures, it senses changes in altitude and automatically adjusts power to maintain a steady CFM. This drive is easy to install and features a connector-based input/output port.

3-Phase VFDs

Invention House manufactures innovative 3-phase variable frequency drives that meet strict, military-grade specifications. This equipment is ideal for cooling fans, blower motors, and radar systems and can withstand extreme temperatures.

400 Hz Motor Drive

Powering aviation engines requires a motor drive that’s durable and compact. Our 400 Hz VFD supports the necessary horsepower for aircraft and is designed to be lightweight and maximize storage space.

Invention House: A Leading Provider of Customizable VFDs and More

The Invention House team understands companies have unique needs for motor drives. As a small, independent company, we’re capable of customizing our products to meet specific requirements. Along with our selection of VFDs, we also offer automated conformal coating machines that reduce costs and improve operator conditions. Our equipment is designed to meet strict military-grade compliance standards and is backed by over 20 years of knowledge and experience. Partnering with us provides peace of mind knowing your equipment suits the application it’s built for. Contact Invention House today to learn more about our innovative VFD equipment.

What Is a VFD?