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Linux device keeps China’s lights lit

Sep 16, 2005 — by LinuxDevices Staff — from the LinuxDevices Archive — views

China's Academy of Electrical Power, a state research group, has used Linux and a real-time database from McObject to build a Phasor Measurement Unit (PMU) aimed at preventing widespread, cascading power failures, such as the one that blacked out much of the northeastern United States and parts of Eastern Canada in… August 2003.

(Click for larger view of the PMU)

The Linux-based PMU is installed in power substations, where it samples voltage stability and other power conditions hundreds of times per second. The data are cached in McObject's eXtremeDB in-memory database before being passed via dedicated communications channels to a central monitoring unit, where the resulting network overview enables managers to provide safe, reliable energy transfers.

The PMU can be rack-mounted, or housed in a normal PC case with a local display
(Click to enlarge)

Versions of the PMU intended to work autonomously in substations are housed in rackmountable cases with no local display. Those for use in central monitoring stations are housed in a normal PC case, with a local display monitor, as shown in the photo above.

According to Dr. Xu Yong, senior scientist at the Academy of Electrical Power, the PMU is based on an IBM PC running Red Hat Linux 9. The PMU software is written in C, while the user interface is written in Java.

Dr. Xu said, “In extensive power networks, system failure can develop too quickly for old security applications to detect and prevent. Because the PMU-based technology is much faster, it alerts operators to dangerous grid conditions in sufficient time to correct problems. This significantly enhances reliability in one of China's largest power networks.”

Dr. Xu added, “Data management is a major PMU function. Our development group determined that incorporating a proven database would both speed up development and result in a more stable end product. We compared McObject's eXtremeDB to several commercial and internally developed databases, and eXtremeDB offered the best combination of performance, reliability, and ease of development.”

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