Automated EPAutomated EPV. RampazzoV. Rampazzo

Development of the software based on the tuning of the differential electrolytic conductance for controlling the Electropolishing process

ISTITUTO NAZIONALE DI FISICA NUCLEARE

LABORATORI NAZIONALI DI LEGNARO

I-V polarization curve for EP

The method consists in computer monitoring the I-V characteristic.

Tuning of the EP process in the minimum Tuning of the EP process in the minimum of the of the differential conductivity differential conductivity dI/dVdI/dV

0

2

4

6

8

10

12

dI/dV I

I [A]

0 1 2 3 4 5 6 V [V]

I/V

Schema of the automated Schema of the automated EPEP

Electrolytic cell Voltage

SupplyPLC

PC Automation Software

DigitalInput-output

Analogical

signals

VOLTAGE CONTROL REGIME

The best working point of the I-V characteristic is searched and followed by during the whole EP process

Field PointField Point®®20102010

PLC: ◦ Industrial computer

Programming language:◦ Labview® 8.5 by

National Instruments®

I/O Modules:◦ Writing and reading

channels send and receive the data

Computer Interface

ETHERNET o RS-232

Channels I/O

Automatic SoftwareAutomatic Software

1. Scan to detect the characteristic curve

2. Calculation of plateau3. Following of minimum on derivative

dI/dV

MovieMovie

Characteristic CurveCharacteristic Curve

Derivarive

calculation

Following the minimumFollowing the minimum Short voltage scan around the minimum found

Recalculation of derivative dI/dV to follow the EP best point

Minumum Range

GraphicGraphic

Graphic plot of characteristic

curve I-V

Short range scan EP

Derivative dI/dV

Manual set of EP working Manual set of EP working pointpoint

Manual set◦it’s possible to put in

another working point

Manual set of EP working Manual set of EP working pointpoint

Adaptation of power supply Adaptation of power supply parametersparameters

Setting of power supply parameter: ◦Maximum Voltage◦Maximum current◦Voltage command range

for voltage and current

ConclusionConclusionThe program finds and follows

automatically the best EP point

All the parameters of process can be changed during the EP

Remote controlRemote control

The analog readings from the Power supply are converted to digital in a PLC and elaborated by the automation software

The digital output from the automation software are converted in voltage signals that drive the Power supply

Remote interface

Thanks for Thanks for attention!attention!