State Grid Shizuishan upgrades grid dynamic perception for new power systems

State Grid Shizuishan Power Supply Company completed the replacement and upgrading of Phasor Measurement Units (PMUs) on July 23 at the 220kV Zhenshuo Substation.

This first dedicated PMU upgrade project involves equipment replacement, bay expansion, and wide-frequency measurement capabilities. The upgrade significantly enhances the substation's dynamic monitoring and data transmission capabilities, reinforcing safe and intelligent grid operation.

PMUs collect real-time data on voltage, current, and phase angles, making them critical for dispatch centers to assess operating conditions and maintain system stability.

To support new power systems, improve dynamic monitoring, and enable response‑based safety assessments, expanding PMU deployment — including conventional and wide‑frequency units — is essential.

The old PMUs at Zhenshuo, however, had aged hardware and limited coverage, monitoring only 12 bays. Their narrow frequency band could not capture non‑power‑frequency disturbances from renewable sources or power electronics, necessitating the upgrade.

To tackle these issues, State Grid Shizuishan formed a special team to refine construction plans and safety measures.

Before work began, technicians thoroughly inspected aging circuits, verified wiring, and completed preparatory tasks such as removing old units and rearranging cables.

During construction, they strictly controlled secondary‑side risks and standardized the full workflow — from installing new equipment and rewiring to parameter configuration, program downloading, and point‑to‑point calibration.

The upgrade expanded the number of monitoring bays from 12 to 16 and added monitoring points for the high‑voltage sides of all four main transformers, thus achieving full coverage of core equipment and eliminating dynamic monitoring blind spots.

After grid‑connection commissioning and dispatch data joint debugging, all collected data now transmits to the dispatch platform in real time.

The new wide‑frequency measurement units support full‑spectrum acquisition, enabling identification of synchronous, supersynchronous, and wide‑frequency oscillations, dynamic power quality tracking, and complete transient disturbance recording.

The successful commissioning addresses the substation's weak wide‑frequency perception, complies with national dispatch requirements for new power systems, and effectively mitigates oscillation risks from grid‑connected renewables.

It provides critical data for main‑station stability analysis and disturbance tracing, establishing an integrated steady‑state, dynamic, and transient grid perception system — further elevating the substation's safety monitoring capabilities.