LabVIEW projects - Power Management

Power Management Application for Methanol Factory

At ChemE the power consumption of an experimental Methanol Factory is being measured with a new Power Management Application. This application also measures the power generated by a Photo Voltaic cell and a Windturbine.
The application emulates a self-supplying environment where the (surplus) energy is first directed to a battery and then to the grid or where the (required) energy is first acquired from a battery and then from the grid.

The hardware

The presented vi connects to a series of Carlo Gavazzi WM14 power analyzers. An Advantech PCI-1601A 2 port RS-422/485 card is used to enable the connection.

Principle

The basic principle of the vi is that three loops will be launched after the initialisation. One loop will walk through the following steps once a second:

• monitor both the current and power values for each connected power analyzer
• calculate the current and power values to or from the battery and the grid
• update the historical data for the last 5 minutes, 1 hour and 1 day
• store the data to disk (to network drive Q: by default)

A second loop will update the data for the selected graph once a second.

A third loop will check for events (=mouse clicks). It's primary use is to act on a click on the 'Lock' or 'Unlock' button.

Utilities

The power consumption/generation is being measured on a continuous basis and the application allows to look back for the values during the last 24 hours. Older data can be found in the data files generated by the application. A separate vi allows to read these data files and converts them to spreadsheet files (comma separated values).

Downloads

energy.zip
This compressed file contains the following files:

main.vi
the main application

main.ini
arbitrary initialisation file which allows to run the application without the actual hardware

wm14.llb
LabVIEW library file supporting the Carlo Gavazzi WM14 power analyzer

energy-support.llb
LabVIEW library file containing the following vi's and controls:

bundle24hr.vi / bundle5min.vi / bundle60min.vi
extracts data from the repective historical data arrays for the corresponding graphs

grid.ctl
boolean control that displays a green arrow poiting upward if power is supplied to the grid or a red arrow point downward if power is demanded from the grid

passwd-decrypt.vi
encrypts a given string ('demon' by default), compares it with a previously encrypted string and returns TRUE if it matches or FALSE if it doesn't match

passwd-encrypt.vi
returns an encrypted string for a given string

shift120sec.vi / shift1sec.vi / shift5sec.vi
shifts new data into the respective historical data arrays

strategy2battery.vi
calculates the amount of energy to send or extract from the battery and/or grid

 

Note: All vi's have been made with LabVIEW 6.1 Full Development System.

See also

For more information on the power analyzer vi's please check the Carlo Gavazzi - WM14 power analyzer page.

Acknowledgement

The presented vi resembles but is a complete makeover of the Battery Management System vi created by TNO-MEP.

Remarks

At the time the department of chemical technology of the Delft University of Technology ChemE was named DelftChemTech.