Data Acquisition and Control

SFW provides the basis of the company's data acquisition and control systems. This includes the ability to reconcile and log data concurrently from multiple sources. Where standard control systems such as PLCs and PID cannot solve a control problem, then AIS has the ability to develop software control that runs on standard PCs.

Turbine monitoring

Delabole wind farm operates 10 wind turbines and provides up to 4 Megawatts of power to the national grid. Each of the turbines requires monitoring for alarms and there is an overall requirement to monitor power and provide statistical analysis and reports.

AIS provided Delabole with a centralised PC-based system for monitoring the turbines. The system links to each of the turbines via a dedicated land line communications links, and to meteorological data loggers via radio links.

Critical parameters are monitored in real-time and alarms are transmitted to maintenance personnel via text messages to their mobiles phones. The system monitors the power produced and provides statistics for actual power versus predicated power based on the wind speed and direction.

Key facts:

• Multiple data sources combined within the PC to provide a complete database for monitoring and logging
• Alarm notification via remote terminals and messaging to mobile phones

Control of waste water treatment

United Utilities (UU, formerly North West Water) processes industrial effluent and returns the cleaned water to the river. The effluent is treated using bacteria and there is a requirement to maintain a consistent level of dissolved oxygen so that the process is effective and the waste water meets stringent quality requirements.

This is a complex control problem as it involves many constraints regarding both the equipment and the process.

AIS provided UU with a PC-based system to monitor and control the process. The system monitors the dissolved Oxygen using special sensors linked to distributed data acquisition modules. Dissolved Oxygen is added to the process through 50KW motors that stir the sludge. Working with UU, AIS developed a specialist control algorithm for switching of the stirrers, taking into account the variable load arriving, switching restrictions and the nature of the process.

Key facts:

• Distributed data acquisition modules used to link the sensors and switch gear direct to the PC
• Working with UU process engineers, AIS developed a dedicated control algorithm. Standard control systems could not solve the problem.