Soft starter and Speed Control of three phase Induction motor Using PLC
Soft starter as the name suggests use of electronic elements like transistors, silicon control rectifiers, etc., along with speed control of a three-phase induction motor with the help of a programmable logic computer (Controller) which is mainly operating for the start of the
2025-06-28 16:29:34 - Adil Khan
Soft starter and Speed Control of three phase Induction motor Using PLC
Project Area of Specialization Electrical/Electronic EngineeringProject SummarySoft starter as the name suggests use of electronic elements like transistors, silicon control rectifiers, etc., along with speed control of a three-phase induction motor with the help of a programmable logic computer (Controller) which is mainly operating for the start of the motor smoothly to save from damaging of windings and to set the speed of the motor according to load. When the motor starts the input current known as inrush I is 3-to-8 time of the rated current. A soft starter decreases this current and saves the motor winding from burning. We can control speed by varying the voltage known as firing angle.
In this project, we are going to use 6 SCR (two anti-parallel SCR at every phase). The principle that we use in this project is by varying the firing angle from PLC, at the gate (G) of SCR to decrease the inrush current to the lowest possible level as well as control the speed of the motor using PWM(Pulse width Modulation). We can control the speed of the motor by changing the duty cycle of PWM.
Project ObjectivesThe main objectives of this project are following
- Give practical shape to our engineering knowledge.
- Improve practical, time management, teamwork, communication, and problem handling skills.
- The main objective of our project is to use the pulses fed to the PLC controller to perform the required action.
- Deep knowledge of PLC coding on the TIA portal.
- Designing of SCRs according to the rating of the motor.
- Decrease the inrush current as possible and control the speed of the motor.
- Control the cost of the final design of this project because in the future we can hold it on market.
- Design of three-phase induction motor.
We can implement this project in the following area
- Steel industries.
- Cement Industries.
- Sugar Plants.
- Rubber & Plastic.
- Textile Industries.
- Machine Tool applications.
- Power Sector.
- Water Supply Scheme.
- Process control applications.
In any industry, the induction motor plays an important role due to its low cost and simplicity. By implementing a monitoring and control system for the speed of the motor, the induction motor can be used in high-performance variable-speed applications. In a number of industries, motors must satisfy very strict speed requirements, both with respect to the range and smoothness of control and also with respect to economical operation. The control of equipment has been performed through the use of computers. Most equipments uses programmable logic controllers (PLC) to connect with computers to monitor each load and electricity-consuming devices.
The most common benefits of this project are given below
- Soft starter limits the inrush current.
- When load demand on the motor decreases then we can decrease the speed and save our energy.
- They protect the device.
- Save energy.
- Increase the lifetime of the device.
- Common demand in industrial applications.
- Less maintenance is required.
- Reduces mechanical jerk and electrical stress on windings.
- Speed control safe our time.
- PLC is widely used in every industry. We can use existing trainer and done this both task by simple coding.
The variable speed drives, till a couple of decades back, had various limitations, such as poor efficiencies, large space, lower speed etc., However, the advent of power electronic devices such as power MOSFETs, IGBTs etc., and also with the introduction of advanced PLC has transformed the scene completely. Today we have variable speed drive systems which are not only in smaller size but also very efficient, highly reliable and meeting all the stringent demands of various industries of modern era.
Final Deliverable of the Project Hardware SystemCore Industry ManufacturingOther Industries Petroleum , Energy , Others Core Technology OthersOther Technologies Blockchain, Robotics, NeuroTechSustainable Development Goals Industry, Innovation and InfrastructureRequired Resources| Item Name | Type | No. of Units | Per Unit Cost (in Rs) | Total (in Rs) |
|---|---|---|---|---|
| Total in (Rs) | 56120 | |||
| SIEMANS PLC 1200 CPU | Equipment | 1 | 50000 | 50000 |
| Three phase induction motor | Equipment | 1 | 5000 | 5000 |
| SCR | Equipment | 6 | 100 | 600 |
| Driver Circuit | Equipment | 6 | 20 | 120 |
| Heat sink | Equipment | 2 | 200 | 400 |