BHEL SUMMER TRAINING INTERNSHIP PROGRAMs

Bharat heavy electrical limited summer training internship.

1. A presentation on Practical Training Undergone At “BHARAT HEAVY ELECTRICALS LIMITED” Submitted For Partial fulfilment for the award of the degree for Bachelor of Technology In Electrical Engineering At Institute OF Technology Gopeshwar Submitted By: Ashutosh Dawre Roll No: 221340105003 Submitted to: Mr. Abhishek Agarwal

2. Bharat Heavy Electricals Limited (BHEL) is India’s largest engineering and manufacturing enterprise in the energy and infrastructure sectors. Established in 1964, BHEL plays a crucial role in the country’s industrial development. It is a public sector undertaking (PSU) under the Ministry of Heavy Industries and Public Enterprises, Government of India. INTRODUCTION

3. HEEP is a critical part of BHEL’s operations, focusing on producing high-capacity turbines, generators, and other essential equipment used in power plants, including thermal, hydro, and nuclear facilities. The plant is equipped with state-of-the-art manufacturing technologies, precision engineering tools, and a dedicated workforce to ensure high-quality, reliable products. Heavy Electrical Equipment Plant (HEEP)

4. HEEP BHEL, Haridwar has divided into 8 blocks: Block Operations Performed Division of Production in HEEP

5. Turbo generators are large electrical machines that convert mechanical energy, typically from a steam or gas turbine, into electrical energy. They are used in power plants to generate electricity on a large scale. Turbo generators are an integral part of thermal power stations (coal, gas, nuclear) and also in some industrial applications where large amounts of electricity are required. Turbo Generators

6. 500 MW Turbo generators at a glance – 2-Pole machine with the following features:- Direct cooling of stator winding with water. Direct hydrogen cooling for rotor. Moralistic insulation system Spring mounted core housing for effective transmission of vibrations. Brushless Excitation system. Vertical hydrogen coolers Salient technical data– Rated output: 588 MVA, 500 MW Terminal voltage: 21 KV Rated stator current: 16 KA Rated frequency: 50 Hz Rated power factor: 0.85 Lag Efficiency: 98.55% Important dimensions & weights – Heaviest lift of generator stator: 255 Tons Rotor weight: 68 Tons Specification of Turbo Generators

7. A balancing tunnel, also known as a vacuum balancing tunnel or high-speed balancing tunnel, is a specialized facility designed to balance large, high-speed rotors, typically used in turbomachinery such as steam turbines, gas turbines, and generators. The tunnel provides a controlled environment for precise balancing, ensuring optimal performance, reliability, and safety of the rotor. Balancing vacuum Tunnel

8. Stator body is a totally enclosed gas tight fabricated structure made-up of high-quality mild steel and austenitic steel. It is suitably ribbed with annular rings in inner walls to ensure high rigidity and strength .The arrangement, location and shape of inner walls is determined by the cooling circuit for the flow of the gas and required mechanical strength and stiffness. The natural frequency of the stator body is well away from any of exciting frequencies. Inner and sidewalls are suitably blanked to house for longitudinal hydrogen gas coolers inside the stator body. Stator Of Turbo Generators

9. Laying of Water-Cooled Winding in the Stator of 500 MW Turbo Generator

10. Stator Winding The stator has a three phase, double layer, short pitched and bar type of windings having two parallel paths. Each slots accommodated two bars. The slot lower bars and slot upper are displaced from each other by one winding pitch and connected together by bus bars inside the stator frame in conformity with the connection diagram.

11. Rotor Winding The rotor comprises of following component: Rotor shaft Rotor winding Rotor wedges and other locating parts for winding Retaining ring Fans Field lead connections

12. The cooling system of a 500 MW turbo generator is critical for maintaining optimal performance and preventing overheating due to the large amount of heat generated during operation. Generators of this size typically utilize hydrogen cooling, and sometimes a combination of hydrogen and water cooling, depending on the specific design and requirements. Cooling Systems

13. For direct cooling of rotor winding cold gas is directed to the rotor end wedges at the turbine and exciter ends. The rotor winding is symmetrical relative to generator centerline and pole axis. Each coil quarter is divided into two cooling zones consists of the rotor end winding and the second one of the winding portion between the rotor body end and the midpoint of the rotor. Cold gas is directed to each cooling zone through separate openings directly before the rotor body end. Cooling of Rotor Cooling of Rotor

14. Cooling of Stator For cooling of the stator core, cold gas is passes to the individual frame compartment via separate cooling gas ducts. From these frames compartment the gas then flow into the air gap through slots and the core where it absorbs the heat from the core. To dissipate the higher losses in core ends the cooling gas section. To ensure effective cooling. These ventilating ducts are supplied from end winding space.

15. The excitation system of a turbo generator provides the necessary field current (DC current) to the rotor winding of a synchronous generator. This field current generates the magnetic field required for the conversion of mechanical energy (from the turbine) into electrical energy by inducing a voltage in the stator windings. Excitation systems play a critical role in maintaining the generator's output voltage, ensuring system stability, and providing reactive power support to the grid. In modern power plants, excitation systems are designed to be highly efficient, fast-acting, and automated for optimal generator performance. Excitation Systems

16. Voltage Regulation : The excitation system controls the output voltage of the generator by adjusting the rotor’s magnetic field. The Automatic Voltage Regulator (AVR) plays a central role in this process. Reactive Power Control : The excitation system controls the flow of reactive power to the grid. Increasing excitation boosts the magnetic field, providing more reactive power, while decreasing excitation absorbs reactive power from the grid. System Stability : The excitation system helps maintain stability in the power grid by responding to disturbances (e.g., load changes, faults). A quick and accurate response from the exciter ensures the generator remains synchronized with the grid. Power Factor Control : By controlling the amount of excitation, the system influences the generator's power factor . Higher excitation leads to a leading power factor, while lower excitation results in a lagging power factor. Functions of Excitation System

17. CERTIFICATE

18. Thank You