Last Updated on October 22, 2023 by Kevin Chen
Electrical drives are mechanisms that use an electric motor to convert electrical energy into another form of energy. These devices are used in a variety of industrial applications to increase torque, reduce speed, or transfer energy between two shafts at different speeds.
Electrical drives can be used in numerous applications, including automation and manufacturing industries, food processing plants, paper mills, and anywhere else where motors are used to drive other equipment. If you’re interested in learning more about the various types of electrical drives and which one is right for your application, read on for an in-depth look at this topic.
The general working principle of electric drive
Before getting into the specifics of the various types of electrical drives, it is helpful to understand the general working principle of an electrical drive.
The basic difference between an electric drive and other types of drives is that the electric drive uses an electromagnet to generate a rotating force, while other types of drives use a rotating mechanical mechanism to generate an electromagnetic force.
In other words, in an electric drive, the rotating force is generated inside the motor (inside the iron core), and in a mechanical drive, the rotating force is generated outside the motor (on the shaft).
Other than the rotating force, electrical drive also generates linear force. This is a force that is perpendicular to the direction of the rotating force. The linear force is generated by applying a voltage to the motor windings. The more voltage that is applied, the greater the linear force will be.
Parts of an Electrical Drive
An electrical drive is capable of executing its key mandates because of the three major components. These are the power modulator, control unit, and sensing unit. Let’s have a brief discussion about these core components.
The primary function of the power modulator is power regulation. It controls or regulates the power from the source into the electrical drive unit. By doing this, it ensures that the drive is able to behave and perform according to the intended characteristics as required by the load.
For example, the power modulator will ensure that sufficient current is supplied to the electrical drive when you want to get the maximum speed or torque. On the other hand, it will reduce the supply whenever you want to slow down or even apply the brakes.
The power modulator is also responsible for the electrical conversion depending on the requirement of the motor. For example, if you are using the DC power source, the modulator will convert it into AC.
The control unit is responsible for the monitoring and control of the electrical drive. It is also responsible for the communication between the power modulator and the sensing unit.
The control unit is also responsible for deciding how much current should be supplied to the electrical drive, depending on what you want to do. For example, if you are in a hurry and want to accelerate quickly, then it will supply maximum current to the drive. However, if you are going uphill or there is a lot of resistance from your load, then it will reduce the current accordingly in order to avoid overloading your system.
The sensing unit serves as an interface between the power modulator and control unit. It senses all things related to your electrical drive such as speed, temperature, torque, etc., which will be used by the control unit in its decision-making process.
For example, if your load requires more torque than what is currently being supplied by your electrical system, then it will send a signal to increase the power supply from your modulator.
Similarly, if there is an excess load on your system due to heavy acceleration or going uphill etc., then it will send a signal for reducing the power supply depending on what you have configured in advance through your system configuration parameters.
The sensing units are also responsible for monitoring all aspects of performance such as speed and temperature etc., which can be used by both users as well as manufacturers of electrical drives such as motor-drive manufacturers in their future
Types of Electrical Drive
There are different classes of electrical drives based on their characteristics and each class has different types of drives. Let’s look at these types and what they do.
Based on the power supply
In this class, we have two main types of electrical drives. These are the AC motor drives and the DC motor drives.
AC electrical drives work on the principle of AC Motors. They are highly efficient and can be used for a variety of applications. Since they work on the principle of AC motors, they require a three-phase power supply. They are very efficient in nature and consume less power.
DC electrical drives work on the principle of DC motors and are also known as brushless DC motor drives due to their absence of brushes. These drives are very popular due to their high efficiency, low maintenance requirements, and low cost when compared to other types of electrical motors such as AC motors or servo motors, etc.
Based on speed
Under this, we have constant speed drive and variable speed drive. A constant speed drive is one that gives constant speed to the motor. For example, we have a motor that is capable of producing a maximum torque of 100 Nm at 1000 rpm. In this case, if we give the command to run at 1500 rpm, it will produce 150 Nm of torque.
The efficiency will be the same for all the speeds. But in variable speed drive, the output torque depends on the speed and hence efficiency decreases with an increase in speed.
Based on control parameters
Under this class, we have vector control drive, constant power drive, and constant torque drive. vector control drive means that the motor is controlled in such a way that the vector sum of the torques on the motor shaft is zero. This means that the sum of all torques produced by a DC/AC/PM synchronous motor must be equal to zero.
The vector control drive is commonly used for linear motion applications such as machine tools or robots. Constant power drive means that the power delivered to the load must be equal to output power irrespective of load changes. In other words, a constant power drive delivers constant power regardless of speed and torque changes in the system. A constant torque drive delivers a fixed amount of torque irrespective of speed and load changes.
Based on the number of motors
Under this classification, we have individual, multi-motor electrical drives, and group drives. As the name suggests, individual electrical drives are systems that employ a single motor to drive the load. On the other hand, multi-motor electrical drives are systems that employ multiple motors to drive the load. Group drives are systems that use one or more motors to control a group of motors in order to perform a specific task.
Advantages of Electrical Drives
Here are some pros that come with using electrical drives:
-They are capable of handling overloads without losing their efficiency
-You can easily modify their speed and torque characteristics without many constraints
-Easy to control even when they are in operation
-High efficiency since they are capable of transforming all the power and energy that is inputted into them into mechanical output
-They are more reliable than their counterparts, the hydraulic drives
-They have a long lifespan
-They are less costly than other types of drives
-They deliver faster response times
Disadvantages of Electrical Drives
Here are some cons that come with using electrical drives:
-High initial cost of investment since you will have to consider other components such as controllers and inverters
-Require regular maintenance
Applications of Electrical Drives
– Driving pumps or fans – Electrical drives are often used to drive centrifugal or axial-flow pumps. Centrifugal pumps use a rotating impeller to move the fluid, and axial-flow pumps use a rotating diffuser to move the fluid.
– Driving a car – An electrical drive can also be used to drive a car. Cars that are powered by electrical drives are referred to as electric cars.
-Industrial production:- Electrical drives are used for industrial production. They are used in the textile industry to drive spinning machines, and they are also used in the paper industry to drive paper drying and calendering machines.
-Driving fans – Electrical drives are also used to drive fans. An electrical motor is often coupled with a fan blade to create an electric fan.
Where to buy Electrical Drives
You can buy electrical drives from many different sources. You can buy electrical drives from a manufacturer, distributor, or supplier. You can also buy electrical drives online from an e-commerce website.
If you are planning to buy electrical drives in China, you will be safer if you do so through a sourcing agent. For example, ai ICRFQ, we will deeply analyze your needs and requirements and then connect you to the right manufacturer or supplier.
Electrical drives can be used in many different applications, and before you decide which drive to use, it is important to consider the advantages and disadvantages of each type of drive.
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