US 11,777,315 B2
Power conversion device suppressing phase jump
Naoki Yamaguchi, Akashi (JP); Yusuke Umezu, Kakogawa (JP); Soichiro Bando, Kobe (JP); and Kazushige Sugimoto, Amagasaki (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Filed by Kawasaki Jukogyo Kabushiki Kaisha, Kobe (JP)
Filed on Jun. 24, 2021, as Appl. No. 17/356,547.
Application 17/356,547 is a continuation of application No. PCT/JP2019/050280, filed on Dec. 23, 2019.
Claims priority of application No. 2018-245120 (JP), filed on Dec. 27, 2018.
Prior Publication US 2021/0320498 A1, Oct. 14, 2021
Int. Cl. H02J 3/32 (2006.01); H02J 3/16 (2006.01); H02M 7/00 (2006.01); H02M 7/797 (2006.01)
CPC H02J 3/32 (2013.01) [H02J 3/16 (2013.01); H02M 7/003 (2013.01); H02M 7/797 (2013.01); H02J 2310/42 (2020.01)] 14 Claims
OG exemplary drawing
 
1. A power conversion device comprising:
a power converter located between AC wiring, to which a power generator and an electrical load are connected, and DC wiring, to which an energy storage is connected, the power converter is configured to convert AC power inputted to the power converter through the AC wiring into DC power and charge the energy storage with the DC power, and to convert DC power inputted to the power converter through the DC wiring, the DC power is discharged from the energy storage, converted into AC power and the AC power is outputted to the AC wiring;
a voltage detector that detects a system voltage at the AC wiring side of the power converter;
an active power obtainer that obtains active power at the AC wiring side of the power converter; and
circuitry that performs power conversion control between the AC wiring and the DC wiring by transmitting a drive signal to the power converter, wherein
the circuitry includes:
a phase calculator that calculates a current phase from the system voltage detected by the voltage detector;
a phase jump angle calculator that calculates a virtual phase that follows temporal changes in the current phase in a lagging manner, and calculates a phase difference between the current phase and the virtual phase as a phase jump angle; and
a drive signal generator that generates the drive signal to the power converter, which is a signal for adjusting active power that is inputted to or outputted from the power converter so as to suppress the phase jump angle, wherein
the phase jump angle calculator includes:
an angular velocity calculator that calculates, on an assumption that a virtual synchronous phase modifier is connected instead of the power conversion device, an angular velocity in the virtual synchronous phase modifier by using the obtained active power and a value that is based on a virtual inertia moment in the virtual synchronous phase modifier; and
an integrator that calculates, as the virtual phase, a phase in the virtual synchronous phase modifier by integrating the angular velocity.