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The Variable Frequency Drive: The Key to Industrial Flexibility and Efficiency.

The industrial world is constantly evolving, always seeking to improve its efficiency and productivity.

One of the tools that proves indispensable in this quest is the variable frequency drive. But what exactly is it, and why is it so crucial for the modern industry sector?

What is a variable frequency drive?

The variable frequency drive, also known as a variable speed drive or frequency converter, is a gem of power electronics designed to optimize the performance of alternating electric motors. Its main function is to precisely regulate the speed and torque of the motor. But how does it achieve this feat?

At the heart of this technology, we find a sophisticated mechanism that adjusts the frequency and continuous voltage of the motor’s power supply. By modifying the frequency of the electrical current that powers the motor, the variable frequency drive directly influences its rotational speed. Therefore, varying the rotational speed becomes an easy and precise task, allowing industrialists to modulate their equipment’s energy consumption according to their needs.

The power electronics integrated into the drive transform the current from a source, often via a transformer, into an adapted continuous voltage. This voltage is then modulated in frequency through a process of vector coupling and control, ensuring perfect adaptation to the demand of the alternating current motor.

The variable frequency drive is much more than a simple frequency converter. It symbolizes modern technology’s evolution towards more efficient management of frequency variation, offering better performance while reducing energy consumption. In an industrial world where efficiency and durability are paramount, this tool proves to be an indispensable ally.

To better understand the principle behind this device, let’s consider its process in three steps:

1.     Conversion to direct current: The input electricity, usually in the form of alternating current, is transformed into direct current through a rectifier.

2.     Frequency modulation: The direct current is then reconverted into alternating current but with a variable frequency, thanks to an inverter.

3.     Motor speed control: When the frequency of the alternating current changes, the rotational speed of the electric motor also changes.

Why do industrialists use variable frequency drives?

The answer is simple: flexibility, energy efficiency, and precise control. Here are some of the main reasons:

• Energy savings: In applications such as fans or pumps, where demand often varies, adjusting the motor speed to actual needs allows for significant energy savings.

• Precision: Variable frequency drives offer rigorous speed control, making industrial processes more precise and optimized.

• Equipment longevity: Motors and machines are less stressed thanks to the progressive starts and stops allowed by variable frequency drives, thus prolonging their lifespan.

• Programmability: Need a particular startup sequence? Or a reverse function? Variable frequency drives can be programmed according to specific operational requirements.

Modern industry, in its constant search for efficiency and productivity, requires tools capable of adapting to changing requirements. The variable frequency drive, with its ability to offer precise control while optimizing energy consumption, proves to be an invaluable ally. For companies concerned with improving their performance while minimizing their costs, it is undoubtedly a wise investment.

What is the difference between a variable frequency drive and a variable speed drive?

The confusion between a variable frequency drive and a variable speed drive is common because in many contexts, these terms are used interchangeably. However, a variable frequency drive is actually a type of variable speed drive.

Variable speed drive

It is a device or system that allows the speed of a motor or mechanism to be modulated. There are different types of variable speed drives, adapted to different types of motors (DC motor, asynchronous motor…) and based on different operating principles. They can be mechanical, such as gearboxes, electrical, such as rheostats for DC motors, or electronic.

Variable frequency drive

This is a specific type of electronic variable speed drive designed for alternating electric motors, mainly asynchronous motors. Its operating principle is based on the modification of the frequency of the alternating current supplied to the motor. By changing this frequency, the rotational speed of the motor is changed. Thanks to this capacity, it allows precise control and effective modulation of the speed of alternating electric motors.

All variable frequency drives are variable speed drives, but not all variable speed drives are necessarily variable frequency drives. The term “variable speed drive” is more general, encompassing a variety of devices designed to control motor speed, while “variable frequency drive” specifically refers to devices that modulate current frequency to control the speed of alternating electric motors.

What are the applications of a variable speed drive in industry?

Variable speed drives, also known as frequency converters, are ubiquitous in the industrial sector. These devices play a crucial role as speed regulators, allowing for precise control of the speed and frequency of electric motors.

kheoos offers you to discover some of their main industrial applications:

• Pump and fan control: In heating, ventilation, and air conditioning (HVAC) systems, variable speed drives allow for adjustment of air or fluid flow, optimizing energy consumption and effectively responding to the variable needs of these systems.

• Machine tools and production equipment: Frequency converters are used to adapt motor power to specific tool requirements, ensuring maximum precision during cutting, milling, or drilling operations.

• Conveyors and transporters: In assembly lines or logistics warehouses, variable frequency drives allow for adjustment of conveyor speed, ensuring safe and efficient handling of goods.

• Mixers and agitators: By controlling the electric motor torque, variable frequency drives ensure homogeneous mixing of materials, whether they are chemicals, foodstuffs or pharmaceuticals.

Variable speed drives, thanks to their advanced control types, offer unprecedented flexibility in optimizing industrial processes. By allowing precise control of motor speed and frequency, they contribute to more efficient and economical production.

To ensure optimal efficiency of your industrial equipment, look no further than kheoos. Whether you are looking for new variable speed drives, used ones, or reconditioned variable frequency drives, kheoos is the specialist in the reuse of industrial spare parts.