IP Library Granted Patent US 11,777,315
Granted Patent B2
US 11,777,315 · App. 17/356,547 · Granted Oct 3, 2023

Power conversion device suppressing phase jump

Inventors: Naoki Yamaguchi (Akashi, JP); Yusuke Umezu (Kakogawa, JP); Soichiro Bando (Kobe, JP); Kazushige Sugimoto (Amagasaki, JP)
Assignee: KAWASAKI JUKOGYO KABUSHIKI KAISHA
H02J3/32H02J3/16H02M7/003H02M7/797H02J2310/42
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Quick Facts
Patent No.
US 11,777,315
App. No.
17/356,547
Granted
Oct 3, 2023
Kind
B2
Abstract

A power converter, a voltage detector that detects a system voltage at an AC wiring side of the power converter; and a controller that performs power conversion control between AC wiring and DC wiring by transmitting a drive signal to the power converter. The controller 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/outputted from the power converter so as to suppress the phase jump angle.

Claims (68)

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.

2. The power conversion device according to claim 1 wherein,

the phase jump angle calculator calculates the virtual phase by integrating twice the phase jump angle in a past time.

3. The power conversion device according to claim 2 , comprising a target current value calculator that calculates a target current value by applying a predetermined filter to the phase jump angle and multiplying an output from the filter by a predetermined proportional gain, wherein

the drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

4. The power conversion device according to claim 1 , wherein

the phase jump angle calculator includes a phase compensator that phase-compensates the active power, and

the phase jump angle calculator inputs the phase-compensated active power to the angular velocity calculator.

5. The power conversion device according to claim 1 , comprising a target current value calculator that calculates a target current value by applying a predetermined filter to the phase jump angle and multiplying an output from the filter by a predetermined proportional gain, wherein

the drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

6. 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;

a target current value calculator that calculates, on an assumption that a virtual synchronous phase modifier is connected instead of the power conversion device, a target current value from a voltage difference between an internal electromotive force voltage in the virtual synchronous phase modifier and the system voltage detected by the voltage detector, and

circuitry that performs power conversion control between the AC wiring and the DC wiring by transmitting a drive signal to the power convener, 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 drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

7. The power conversion device according to claim 6 , wherein

the target current value calculator calculates an active current component and a reactive current component each as the target current value, and

the drive signal generator generates the drive signal for adjusting the active power that is inputted to or outputted from the power converter so as to suppress the phase jump angle by using the calculated active current component and for adjusting reactive power that is inputted to or outputted from the power converter so as to suppress a voltage variation by using the calculated reactive current component.

8. 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 means for storing energy is connected, the power converter configured to convert AC power inputted to the power converter through the AC wiring into DC power and charge the means for storing energy 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 means for storing energy, converted into AC power and the AC power is outputted to the AC wiring;

means for detecting voltage 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 means for detecting voltage;

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.

9. The power conversion device according to claim 8 wherein,

the phase jump angle calculator calculates the virtual phase by integrating twice the phase jump angle in a past time.

10. The power conversion device according to claim 9 , comprising a target current value calculator that calculates a target current value by applying a predetermined filter to the phase jump angle and multiplying an output from the filter by a predetermined proportional gain, wherein

the drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

11. The power conversion device according to claim 8 , wherein

the phase jump angle calculator includes a phase compensator that phase-compensates the active power, and

the phase jump angle calculator inputs the phase-compensated active power to the angular velocity calculator.

12. The power conversion device according to claim 8 , comprising a target current value calculator that calculates a target current value by applying a predetermined filter to the phase jump angle and multiplying an output from the filter by a predetermined proportional gain, wherein

the drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

13. 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 means for storing energy is connected, the power converter configured to convert AC power inputted to the power converter through the AC wiring into DC power and charge the means for storing energy 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 means for storing energy, converted into AC power and the AC power is outputted to the AC wiring;

means for detecting voltage that detects a system voltage at the AC wiring side of the power converter;

a target current value calculator that calculates, on an assumption that a virtual synchronous phase modifier is connected instead of the power conversion device, a target current value from a voltage difference between an internal electromotive force voltage in the virtual synchronous phase modifier and the system voltage detected by the means for detecting voltage, 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 means for detecting voltage;

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 drive signal generator generates the drive signal such that an alternating current outputted from the power converter to the AC wiring is adjusted to the target current value.

14. The power conversion device according to claim 13 , wherein

the target current value calculator calculates an active current component and a reactive current component each as the target current value, and

the drive signal generator generates the drive signal for adjusting the active power that is inputted to or outputted from the power converter so as to suppress the phase jump angle by using the calculated active current component and for adjusting reactive power that is inputted to or outputted from the power converter so as to suppress a voltage variation by using the calculated reactive current component.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 24, 2021
From: YAMAGUCHI, NAOKI; UMEZU, YUSUKE; BANDO, SOICHIRO; SUGIMOTO, KAZUSHIGE
To: KAWASAKI JUKOGYO KABUSHIKI KAISHA
Reel/Frame 056650/0056 →
Priority Claims (1)
JP 2018-245120 · Dec 27, 2018 · national
Continuity (2)
Continuation PCTJP2019050280 · Dec 23, 2019
Related Publication 20210320498A1 · Oct 14, 2021