Electrical Drives and Control Systems
An electrical drive is a device used to control the speed or torque of an electrical motor. It can also be used to accurately control the position of the motor or other devices in specific applications. This article provides an overview of electrical drive and control systems and their various uses in industry.
Electricity is a source of power for motion control in industry. Electric drives and controls are the systems used to control the speed and direction of motors and other loads, in order to move them in a specific direction or at a certain speed. Generally speaking, the electrical drives are divided into two categories, namely servo drive and open loop drive. Servo drives consist of the motor, encoder, commutator, and control unit, which together form a closed-loop system. The encoder provides feedback to the control unit, which in turn adjusts the speed or torque of the motor as needed.
On the other hand, open-loop drives only require a motor and a control unit for operation. These are approved for simple speed and position control, but are not as accurate or reliable as the servo systems. Open-loop drives are usually used in applications where the environment or load is changing constantly, such as conveyor systems or production lines.
Once the electric drive is installed and connected, it must be controlled through some form of switching device, such as contactors, relays, solid-state switches, and transistors. These devices allow operators to turn on and off the motor, as well as change its speed and direction. In motor control applications, speed is often regulated using a variable frequency drive (VFD), a type of motor control device that regulates the motor’s speed in a continuous manner.
In addition to switching devices, there are other types of control devices used in modern electrical systems. These include temperature, speed and current sensors, motor starters, brakes, and position sensors. All of these components are integrated together in a system known as the “power train”, which is responsible for controlling the rotational motion generated by the motor(s).
The control system is the “brain” of the power train and is responsible for the overall control and operation of the power train. This system is usually integrated with a programmable logic controller (PLC), which serves as the user-interface between the system and the operator. The PLC can be programmed to automatically adjust the speed or torque of the motor(s) to maintain the required operating speed or position of the load.
In addition to the electrical drives, control systems, and power trains, there are other components and devices that are often integrated into industrial systems. These include power electronics, which are devices used to convert AC to DC or DC to AC, as well as protective devices like circuit breakers and fuses, which prevent overload and other problems in the system.
Overall, the electrical drive and control systems are essential components in modern industrial systems. They provide a reliable and efficient way to control motors and other loads in a variety of applications. This is why they remain a key part of the industrial automation process.
