The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 17, 2025
Filed:
Aug. 01, 2022
Hitachi, Ltd., Tokyo, JP;
Ravikant Pandey, Tokyo, JP;
Daichi Kato, Tokyo, JP;
Tohru Yoshihara, Tokyo, JP;
Shinya Ohara, Tokyo, JP;
Yutaka Kokai, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A power grid monitoring system includes a storage unit that stores power control system (PCS) impedance data indicative of a PCS impedance that is an impedance of a PCS-based energy source at a plurality of operation points, the PCS-based energy source being connected to an electric power system, the PCS-based energy source including a voltage source and a PCS that regulates power generated by the voltage source and supplies the power to the electric power system, a real time calculation unit that calculates a power grid impedance based on a power flow measured at a point of connection where the PCS-based energy source and the electric power system are connected to each other, the power grid impedance being an impedance of the electric power system, and a stability check unit that performs a stability check to detect low frequency oscillation (LFO) at the point of connection based on the PCS impedance data and the power grid impedance.