MUMBAI, India, June 6 -- Intellectual Property India has published a patent application (202517016568 A) filed by Fuji Electric Co. Ltd., Kanagawa, Japan, on Feb. 25, for 'power conversion device and detection method.'
Inventor(s) include Hayashi, Takashi.
The application for the patent was published on June 6, under issue no. 23/2025.
According to the abstract released by the Intellectual Property India: "This power conversion device, which can be interconnected to a power system, has a virtual synchronous generator function. The power conversion device comprises: a frequency feedback unit that calculates a prescribed transfer function for a frequency of the virtual synchronous generator function or a voltage at an interconnection point with the power system, and then outputs a processing result to which upper and lower limits are applied; an addition unit that outputs a second amplitude command value obtained by adding the processing result and a prescribed first amplitude command value relating to the voltage at the interconnection point; an interconnection point voltage amplitude control unit that generates an inverter output voltage amplitude command value on the basis of the second amplitude command value and the amplitude of the voltage at the interconnection point; a voltage output unit that generates a three-phase AC voltage on the basis of the phase in the virtual synchronous generator function and the inverter output voltage amplitude command value; and an independent operation detection unit that detects that the power conversion device is in an independent operation state of being separated from the power system if the processing result has reached the upper/lower limit. The transfer function has at least a secondary polynomial of a Laplace operator in the denominator and a primary monomial of the Laplace operator in the numerator. With respect to the denominator of a closed-loop transfer function in which a phase change as the output of a virtual synchronous generator having an effective power as an input, a voltage amplitude change as the result of calculating a prescribed transfer function having the frequency of the virtual synchronous generator or the interconnection point voltage frequency as an input, and an effective power change due to the phase change and the voltage amplitude change are consolidated and considered one closed loop system, the coefficients in the polynomial and the monomial are given so that the denominator becomes a stable polynomial if the power conversion device is interconnected with the power system, and becomes an unstable polynomial if the power conversion device is operating independently."
The patent application was internationally filed on Mar. 06, 2024, under International application No.PCT/JP2024/008423.
Disclaimer: Curated by HT Syndication.
