PowerGen_ilab

Power Flow Control in syncronous Generators

Introduction

Students do this laboratory as part of their course during the normal laboratory time. Due to the availability of the equipment and scheduled time, this is carried out in groups. This results in not all students getting hands on experience. When they write their report also, they do not get to see the errors that they have in measurements and discuss them appropriately (since they all have the same set of data.). By making the laboratory available most of the time of a day or 24hrs/7 days a week, the students could schedule their own time and gain the valuable hands on experience. To this end the iLabs comes in handy.

A virtual laboratory using the generator motor unit, with Labview for data collection and analysis, and iLabs for managing the access control is being proposed.

The iLabs would also allow the students at RMIT to access virtual laboratories set up worldwide. For example Queensland University is setting up Characterisation of an Induction motor that would be useful for our students. MIT has micro-electronics laboratories online available for students who gets authenticated by a local iLabs server. There is some interest in using the Cambridge Universities laboratories on Heat Exchangers. This first step will allow our students to gain access to worldwide labs that are available via iLabs. When our students work some American institutions have their capacity idling and when our systems idle, some other students are working.

iLabs functions as a broker with the other institutions. Our students are authenticated by our iLabs server and iLabs broker their access to the worldwide laboratories. Similarly a student from another institution wanting access to our laboratories, have to be authenticated by their institutions iLabs server and brokered access with our Laboratory computers. iLabs will have local policies set up that will determine who can gain access to these laboratories. This is set up based on requests made by academics of the other institutions for their students. In the long terms this would have to be a tool within our DLS offering.

Description of the experiment

As shown in the diagram above the variable frequency inverter fed Induction Motor is driving the Generator. Induction motor represents the Turbine in real life situations. The generator is loaded. Induction motor is driven by V/F inverter. This controls the torque provided on the generator shaft. With increasing torque the real power generated goes up. When the field voltage is increased the reactive power generated by the generator goes up but not the real power delivered. Effectively, the increased field current increases the generator voltage behind its reactance while the mains supply maintains its terminal voltage at the system voltage level.

The students are expected to increase the field current while the shaft torque is held constant and measure the output current and Power. Then the torque is changed by changing the inverter frequency and the same measurements are repeated. Plot these as characteristics and interpret the data. This is what happens in the laboratory session.

In a virtual set up, the measurements are done by the Labview computer through a data acquisition card and the control is achieved through the same. When the student is given access control, no one else can gain access to this until his experiment is finished or timed out.

Students access is authenticated by the iLabs based on set criteria.

Equipment needed

As the workbench with the Inverter/motor/generator is already available, only the data acquisition and control as well as the iLabs hardware and software need be provided to accomplish this.

Data Acquisition/Control

• Standard PC - Already available, could be used for this purpose
• Labview - Ver 7.1 is available but Ver 8 is needed for interfacing with iLabs. We need to upgrade the version that we have to version 8 and that will enable us to move the license to the portfolio level.
• Other miscellaneous signal conditioning circuits

iLabs Server Computer
To be hosted on the back of a server within SET .

Project Timelines

Project Staff:

Consultants:
Joel Carpenter UQ
Mark Shulz UQ

It is intended to complete this project by Dec 2006.

Description Timing Responsibility