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US 11,637,428 B2Granted
Selective power oscillation damping control system with damping ratio dynamic gain and method for the same
AssigneeMitsubishi Electric Power Products, Inc.
InventorsDavid Edward Roop, Samantha Ann Morello, Tamojit Chakraborty
Life of this patent
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Abstract
A system and method to selectively pass and damp oscillations in an electric power grid via a controller of a power electronic device irrespective of the modes of the power oscillations. The system and method includes multiple limiters having dynamic limits that are openable and closeable to control the response of the controller, damping ratio dynamic gain control logic that determines a dynamic gain for a control signal based on the oscillation characteristics of one or more input signals, and pulse counter logic to selectively control at least one of the limiters based on the pulse count of the control signal.
Claims21
A power oscillation damping system for an electric power grid, comprising:
- a power electronic device configured to generate active power or reactive power, or regulate the electric power grid;
- and
- a controller configured to selectively pass and damp oscillations of one or more input signals from the electric power grid, the controller being coupled to memory and being configured to:
- generate a power oscillation damper (POD) control signal based on the one or more input signals;
- determine a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- apply the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- input the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, the dynamic limits defining a maximum output of the controller;
- count, via a counter, each pulse in the POD control signal with respect to time, the pulse being a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively open and close the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- and
- output the POD control signal in response to the output signal limiter being opened,
- reset the counter in response to no pulses being detected within a first predetermined period of time,
- reset the first predetermined period of time in response to a pulse being detected,
- close the dynamic limits of the output signal limiter in response to the pulse count reaching a maximum pulse count within a second predetermined period of time,
- close the dynamic limits of the output signal limiter in response to the pulse count being incremented within the first predetermined period of time of the second predetermined period of time elapsing,
- open the dynamic limits of the output signal limiter in response to the maximum pulse count not being exceeded within the second predetermined period of time and the pulse count not being incremented within first predetermined period of time of the second predetermined period of time elapsing, and
- limit the POD control signal by the dynamic limits of the output signal limiter.
14 more elements
A power oscillation damping system for an electric power grid, comprising:
- a power electronic device configured to generate active power or reactive power, or regulate the electric power grid;
- and
- a controller configured to selectively pass and damp oscillations of one or more input signals from the electric power grid, the controller being coupled to memory and being configured to:
- generate a power oscillation damper (POD) control signal based on the one or more input signals;
- determine a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- apply the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- input the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, the dynamic limits defining a maximum output of the controller;
- count, via a counter, each pulse in the POD control signal with respect to time, the pulse being a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively open and close the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- and
- output the POD control signal in response to the output signal limiter being opened,
- wherein the controller is further configured to determine the dynamic gain based on the one or more input signals by:
- taking an absolute value of the POD control signal having a DC-offset removed;
- applying an integrator with unity feedback to the absolute value of the POD control signal;
- determining a rate of change in the POD control signal after the integrator, which represents a rate of damping of the oscillations;
- limiting the POD control signal by a dynamic limiter, which has dynamic limits that are openable and closeable, the dynamic limits of the dynamic limiter defining a maximum damping rate and a minimum damping rate of oscillation range to be acted upon;
- determining a dynamic gain scaling factor based on a limited damping rate of the oscillations;
- and
- applying the dynamic gain scaling factor to the POD control signal as the dynamic gain.
16 more elements
A computer-implemented method to selectively pass and damp oscillations in an electric power grid via a power electronic device, comprising:
- generating, via a controller, a power oscillation damper (POD) control signal based on one or more input signals from the electric power grid;
- determining a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- applying the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- inputting the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, wherein the dynamic limits define a maximum output of the controller;
- counting, via a counter, each pulse in the POD control signal with respect to time, wherein the pulse is a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively opening and closing the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- outputting the POD control signal in response to the output signal limiter being opened,
- resetting the counter in response to no pulses being detected within a first predetermined period of time,
- resetting the first predetermined period of time in response to a pulse being detected,
- closing the dynamic limits of the output signal limiter in response to the pulse count reaching a maximum pulse count within a second predetermined period of time,
- closing the dynamic limits of the output signal limiter in response to the pulse count being incremented within the first predetermined period of time of the second predetermined period of time elapsing,
- opening the dynamic limits of the output signal limiter in response to the maximum pulse count not being exceeded within the second predetermined period of time and the pulse count not being incremented within first predetermined period of time of the second predetermined period of time elapsing, and
- limiting the POD control signal by the dynamic limits of the output signal limiter.
10 more elements
A computer-implemented method to selectively pass and damp oscillations in an electric power grid via a power electronic device, comprising:
- generating, via a controller, a power oscillation damper (POD) control signal based on one or more input signals from the electric power grid;
- determining a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- applying the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- inputting the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, wherein the dynamic limits define a maximum output of the controller;
- counting, via a counter, each pulse in the POD control signal with respect to time, wherein the pulse is a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively opening and closing the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- and
- outputting the POD control signal in response to the output signal limiter being opened,
- wherein the determining of the dynamic gain based on the one or more input signals further comprises:
- taking an absolute value of the POD control signal having a DC-offset removed;
- applying an integrator with unity feedback to the absolute value of the POD control signal;
- determining a rate of change in the POD control signal after the integrator, which represents a rate of damping of the oscillations;
- limiting the POD control signal by a dynamic limiter, which has dynamic limits that are openable and closeable, the dynamic limits of the dynamic limiter defining a maximum damping rate and a minimum damping rate of oscillation range to be acted upon;
- determining a dynamic gain scaling factor based on a limited damping rate of the oscillations;
- and
- applying the dynamic gain scaling factor to the POD control signal as the dynamic gain.
13 more elements
A non-transitory computer readable medium comprising executable instructions for performing a computer-implemented method to selectively pass and damp oscillations of an electric power grid via a power electronic device, comprising:
- generating, via a controller, a power oscillation damper (POD) control signal based on one or more input signals from the electric power grid;
- determining a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- applying the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- inputting the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, wherein the dynamic limits define a maximum output of the controller;
- counting, via a counter, each pulse in the POD control signal with respect to time, wherein the pulse is a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively opening and closing the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- outputting the POD control signal in response to the output signal limiter being opened,
- resetting the counter in response to no pulses being detected within a first predetermined period of time,
- resetting the first predetermined period of time in response to a pulse being detected,
- closing the dynamic limits of the output signal limiter in response to the pulse count reaching a maximum pulse count within a second predetermined period of time,
- closing the dynamic limits of the output signal limiter in response to the pulse count being incremented within the first predetermined period of time of the second predetermined period of time elapsing,
- opening the dynamic limits of the output signal limiter in response to the maximum pulse count not being exceeded within the second predetermined period of time and the pulse count not being incremented within first predetermined period of time of the second predetermined period of time elapsing, and
- limiting the POD control signal by the dynamic limits of the output signal limiter.
10 more elements
A non-transitory computer readable medium comprising executable instructions for performing a computer-implemented method to selectively pass and damp oscillations of an electric power grid via a power electronic device, comprising:
- generating, via a controller, a power oscillation damper (POD) control signal based on one or more input signals from the electric power grid;
- determining a dynamic gain based on an amplitude of the oscillations, a duration of the oscillations, and a rate of damping of the oscillations in the one or more input signals;
- applying the dynamic gain to the POD control signal to modify the amplitude of the POD control signal;
- inputting the POD control signal having the dynamic gain into an output signal limiter having dynamic limits that are openable and closeable, wherein the dynamic limits define a maximum output of the controller;
- counting, via a counter, each pulse in the POD control signal with respect to time, wherein the pulse is a rising edge of the POD control signal that deviates in a positive direction or a negative direction from zero;
- selectively opening and closing the dynamic limits of the output signal limiter based on a pulse count with respect to time;
- and
- outputting the POD control signal in response to the output signal limiter being opened,
- wherein the determining of the dynamic gain based on the one or more input signals further comprises:
- taking an absolute value of the POD control signal having a DC-offset removed;
- applying an integrator with unity feedback to the absolute value of the POD control signal;
- determining a rate of change in the POD control signal after the integrator, which represents a rate of damping of the oscillations;
- limiting the POD control signal by a dynamic limiter, which has dynamic limits that are openable and closeable, the dynamic limits of the dynamic limiter defining a maximum damping rate and a minimum damping rate of oscillation range to be acted upon;
- determining a dynamic gain scaling factor based on a limited damping rate of the oscillations;
- and
- applying the dynamic gain scaling factor to the POD control signal as the dynamic gain.
13 more elements
Dependencies are inferred from the claim text.