Instabilities like disruptions or fluctuations in the power supplied by the grid to business are especially painful to data centres where high availability is a core concern.
For that reason, a Chinese communications company wanted to monitor the power provided by the city’s 220 V/50 Hz grid for over-and-under voltages. It desired not only to collect the data, but also to log and store it over a longer period of time. In addition, they required a sampling rate of 10 kHz and the analysis of the 3-phase power. The planned system should also issue different alarms.
An off-the-shelf solution was hard to find, so the company settled for a Raspberry Pi together with a MCC 118 DAQ HAT for the monitoring system, as the MCC 118 can measure multiple analogue inputs with a high accuracy at high sampling rates. The Open-Source library software available for this board simplifies the access to its functionality.
The 12-bit analogue-to-digital converter (ADC) of the MCC 118 has 8 single-ended inputs with a +/- 10 V input range and a sampling rate of 100 kS/s for single-point or waveform measurements. Developers can assemble up to eight MCC HATs on top of a single Raspberry Pi. Such a stack results in up to 64 input channels with a maximum throughput rate of 320 kS/s.
The company’s monitoring system uses six out of the eight analogue input channels for voltage measurements. For the power calculation, it utilizes the NumPy library for Python. This library simplifies various mathematical operations on large arrays. The software developed by the company writes the data to a hard disk once the data acquired exceeds either the expected cycle minimum or maximum values. One GPIO of the Raspberry Pi then turns on an LED as an early warning.
All this resulted in a monitoring and analysis system that is available 24/7. Its deployment improved the reliability of the company’s equipment and reduced the downtime of their facility. Get all the project details on the MCC website.