Active power conversion apparatus, system, and method for use in active power conversion apparatus
AssigneeHuawei Digital Power Technologies Co., Ltd.
InventorFrancisco Daniel Freijedo Fernández
Life of this patent
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Abstract
An active power conversion apparatus (APCA) estimates a grid frequency estimation of an electric grid connected to the APCA. The APCA includes a controller for receiving measurements of at least one phase current between the APCA, and the electric grid. The controller converts the at least one phase current to at least one synchronous reference frame, and determines direct and quadrature current references to be used in the grid frequency estimation. The controller determines a use of frequency estimation as a manipulated variable that forces to zero at least one of the average values of current error signals.
Claims20
An active power conversion apparatus (APCA) configured to estimate a grid frequency of an electric grid connected to the APCA, the APCA comprising:
- a controller configured to:
- receive measurements of at least one phase current between the APCA and the electric grid;
- convert the at least one phase current to at least one synchronous reference frame;
- determine direct and quadrature current references to be used in the grid frequency estimation;
- determine a use frequency estimation as a manipulated variable that forces to zero at least one of average values of current error signals;
- and
- bound a state variable of the APCA to avoid division by zero problems,
- wherein the state variable represents a direct current measurement or reference.
A system comprising an active power conversion apparatus (APCA) configured to estimate a grid frequency of an electric grid connected to the APCA, the APCA comprising:
- a controller configured to:
- receive measurements of at least one phase current between the APCA and the electric grid;
- convert the at least one phase current to at least one synchronous reference frame;
- determine direct and quadrature current references to be used in the grid frequency estimation;
- determine a use frequency estimation as a manipulated variable that forces to zero at least one of an average values of current error signals;
- and
- bound a state variable of the APCA to avoid division by zero problems,
- wherein the state variable represents a direct current measurement or reference;
- and
- a current control (CC) block comprising a pulse width modulation (PWM) block, and wherein the CC block is configured to set references for the PWM block as a function of current references, alternating current (AC) measurements, and a phase-angle obtained by integration of an estimated frequency.
A method for use in an active power conversion apparatus (APCA) configured to estimate a grid frequency of an electric grid connected to the APCA, the method comprising:
- receiving measurements of at least one phase current between the APCA and the electric grid;
- converting the at least one phase current to at least one synchronous reference frame;
- determining direct and quadrature current references to be used in the grid frequency estimation;
- and
- determining a use frequency estimation as a manipulated variable that forces to zero at least one of average values of current error signals;
- and
- bounding a second state variable of the APCA to avoid division by zero problems,
- wherein the state variable represents a direct current measurement or reference.
Dependencies are inferred from the claim text.