Device for inrush current minimization in �three phase transformers

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Power Electronics for Renewable Integration (PERI) Laboratory,

Department of Electrical Engineering, Indian Institute of Technology Kanpur, India

ID: IIGPUTVQ4N93K

TEAM INTRODUCTION

Parvraj Pachore

• B Tech from WCE, Sangli, 2015
• Currently pursuing M. Tech in IITK
• Expected Graduation: Dec 2019
• Previously worked with ThyssenKrupp Industries India, Pimpri, Pune

Nachiketa Deshmukh

• B Tech from WCE, Sangli, 2015
• Currently pursuing Ph.D. in IITK
• Expected Graduation: Dec 2021
• Previously worked with Petrofac Engineering India Ltd., Mumbai, India

Mentor: Dr. Sandeep Anand, Assistant Professor

Department of Electrical Engineering,

Indian Institute of Technology Kanpur, India

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MOTIVATION

Solar Generation scenario in India:

• Achieved: 20GW by Jan 2018
• Target: 100GW by 2022
• Solar power in India has been growing at a rate of 113% year over year
• Most of the generation of is through solar generation plants (91%)
• No-load losses in interconnecting transformers during zero generation period: 4-5%
• Requires frequent switching to avoid no-load losses

[Source: Wikipedia, Bridge to India]

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[Source: Wikipedia]

INRUSH CURRENT AND IT’S MINIMIZATION

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• Switching of the transformer leads to generation of high magnetizing inrush currents: 7 to 10 times of rated transformer current
• It is sufficient to minimize inrush current to a value less than 1 pu

PROPOSED SOLUTION AND TECHNICAL INNOVATION

Finding an optimum instant to energize the transformer to avoid core saturation

The developed device works for minimization in inrush currents in three phase transformers energized using three phase gang operated circuit breakers

Eliminates use of flux measurement element: Reduction in cost

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DEVELOPMENT STAGES OF THE PROTOTYPE

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Jan-May 2017

June-Aug 2017

Sept-Oct 2017

Nov-Dec 2017

Controller-In-Loop

test with RTDS

RTDS

simulation

Development of RTDS

interfacing board

Development of

Inrush Minimization

PCB_1

Feb & May 2018

Field test at

NTPC-Dadri

Feb-May 2018

Nov 2018

Jan 2019

Development of

field compatible

prototype

Lab test and

IITK field test

Field test at

NTPC-Faridabad

PROTOTYPE DEVELOPMENT AND CONNECTION DIAGRAM

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TESTS AND RESULTS(1)

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A. RTDS test

B. LAB test

C. Field test

TESTS AND RESULTS(2)

4.92 W/In³

9.83 W/In³

17.87 W/In³

5.36 W/In³

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RTDS test: 6 pu to 0.7 pu

LAB test: 4.2 pu to 1.2 pu

Field test: 5.3 pu to 2.87 pu

EXTENDED APPLICATIONS FOR TRANSFORMER SWITCHING

Generation

Transmission

Distribution

Renewable energy

generation

Hydro-

generation

HVDC-substation

Large industrial

And domestic loads

Railways and transportation loads

Distribution

Transformers

High Voltage Transformers

CAPACITOR AND REACTOR SWITCHING

Capacitor: Controlled closing and Reactor: Controlled opening

High voltage

line switching

Reactor

Capacitor

Shunt Reactor

/ Filter

Capacitor

Bank

Use of smart grid and SCADA would increase switching operations in power system

PROTOTYPE ROADMAP

CURRENT

STAGE

MARKET ANALYSIS(1)

Indian transformer industry is estimated to grow with more than 10% CAGR in next 5 years to cater increasing power,

Powergrid:

• Before 5 years, no CSD was installed in Indian EHV AC power system
• Installation of more than 300 CSD for reactors and transformers (majorly reactors) for 400kV and above voltage range in last 5 years, whereas worldwide 4000 CSDs were installed by 2007

Increase of number of capacitor and reactor banks: Same rate as transformer

Source: CIGRE survey

[Source: Electrical and Power Review]

MARKET ANALYSIS(2)

Low cost

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The existing products are invasive in nature for flux measurement, however our method estimates the flux values

Target Indian Customers:

• PowerGrid
• State Electricity Cos
• Private Electricity Cos
• Transformer manufacturers
• CB manufacturers

Where do we stand-out?

Applicable for all CBs, hence all voltage ranges

BUDGET

Assumption: All equipment are not necessary as we are using the test equipment already available in IIT Kanpur.

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THANK YOU!