Grid-forming control of inverter-based resource using virtual impedance

1. A method for providing grid-forming control of an inverter-based resource connected to an electrical grid, the method comprising:

providing the inverter-based resource, the inverter-based resource comprising:

a generator or absorber of electrical power,

a grid-forming terminal, and

grid-forming converter controls;

providing, via a processor, a virtual impedance value, X P , at a node between the generator or absorber of electrical power and the grid-forming terminal and a virtual impedance value, X G , at a node between the grid-forming terminal and a remote virtual voltage;

determining a voltage drop across virtual impedance values, X P and X G , using at least one current feedback signal, wherein the voltage drop comprises a voltage magnitude and a voltage angle;

receiving one or more voltage or current signals of the inverter-based resource, wherein the one or more voltage or current signals comprises, at least, a virtual voltage magnitude or a virtual voltage angle of the generator or absorber of electrical power; and,

determining a control signal for the inverter-based resource as a function of the voltage drop and the one or more voltage or current signals, wherein determining the control signal for the inverter-based resource further comprises:

calculating a control command for the inverter-based resource as a function of a virtual voltage command comprising a virtual voltage magnitude command, a virtual voltage angle command, and a voltage drop by subtracting the voltage drop across the virtual impedance value, X P , from the virtual voltage command to obtain the control command for the inverter-based resource.

2. The method of claim 1 , wherein the one or more voltage or current signals for the virtual impedance value, X G , comprises, at least, a physical voltage feedback signal.

3. The method of claim 2 , wherein determining the control signal for the inverter-based resource as a function of the voltage drop across the virtual impedance value, X G , and the one or more voltage or current signals further comprises:

determining a remote, virtual voltage feedback signal as a function of the physical voltage feedback signal and the voltage drop.

4. The method of claim 3 , wherein determining the remote, virtual voltage feedback signal as a function of the physical voltage feedback signal and the voltage drop further comprises:

subtracting the voltage drop across the virtual impedance value, X G , from the physical voltage feedback signal.

5. The method of claim 3 , wherein determining the control signal for the inverter-based resource as a function of the voltage drop across the virtual impedance value, X G , and the one or more voltage or current signals further comprises:

calculating an angle input of the remote voltage feedback signal;

providing the angle input to a phase-locked loop regulator of the inverter-based resource; and

generating a phase-locked loop angle and a phase-locked loop frequency for the inverter-based resource based on the angle input.

6. The method of claim 1 , wherein the inverter-based resource comprises at least one of a wind turbine power system, a solar inverter, an energy storage system, a STATCOM, or a hydro-power system.

7. A method for providing grid-forming control of an inverter-based resource connected to an electrical grid, the method comprising:

providing the inverter-based resource, the inverter-based resource comprising:

a generator or absorber of electrical power,

a grid-forming terminal, and

grid-forming converter controls;

providing, via a processor, a virtual impedance value, X P , at a node between the generator or absorber of electrical power and the grid-forming terminal physical converter and a virtual impedance value, X G , at a node between the grid-forming terminal and a remote virtual voltage;

determining a voltage drop across virtual impedance values, X P and X G using at least one current feedback signal;

receiving one or more voltage or current signals of the inverter-based resource, wherein the one or more voltage or current signals comprises, at least, a physical voltage feedback signal; and,

determining a control signal for the inverter-based resource as a function of the voltage drop and the one or more voltage or current signals, wherein determining the control signal comprises:

determining a remote, virtual voltage feedback signal as a function of the physical voltage feedback signal and the voltage drop by subtracting the voltage drop across the virtual impedance value, X G , from the physical voltage feedback signal.

8. The method of claim 7 , wherein the inverter-based resource comprises at least one of a wind turbine power system, a solar inverter, an energy storage system, a STATCOM, or a hydro-power system.

9. A system for providing grid-forming control of an inverter-based resource connected to an electrical grid, the system comprising:

the inverter-based resource, the inverter-based resource comprising:

a generator or absorber of electrical power,

a grid-forming terminal, and

grid-forming converter controls, and;

a controller comprising at least one processor, the at least one processor configured to perform a plurality of operations, the plurality of operations comprising:

providing, via a processor, a virtual impedance value, X P , at a node between the generator or absorber of electrical power and the grid-forming terminal and a virtual impedance value, X G , at a node between the grid-forming terminal and a remote virtual voltage ;

determining a voltage drop across the virtual impedance values, X P and X G using at least one current feedback signal and,

implementing the virtual impedances, X P and X G, into one or more control signals for the inverter-based resource so as to tune at least one of an active power output of the inverter-based resource for changes in an angle for a network outside of the inverter-based resource or decoupling grid angle estimation through a phase-locked loop of the inverter-based resource for changes in the active power output of the inverter-based resource, wherein implementing the virtual impedances comprises:

calculating a control command for the inverter-based resource as a function of a virtual voltage command comprising a virtual voltage magnitude command, a virtual voltage angle command, and the voltage drop; and

determining a remote, virtual voltage feedback signal as a function of a physical voltage feedback signal and the voltage drop;

calculating an angle of the remote voltage feedback signal;

providing the angle to a phase-locked loop regulator of the inverter-based resource; and

generating a phase-locked loop angle and a phase-locked loop frequency for the inverter-based resource based on the angle input.

10. The system of claim 9 , wherein determining the remote, virtual voltage feedback signal as a function of the physical voltage feedback signal and the voltage drop further comprises:

subtracting the voltage drop across the virtual impedance value X G , from the physical voltage feedback signal.