Frequency measurement for electric power delivery system
First Claim
1. A system configured to determine a variable period of an input waveform, the system comprising:
- an input configured to receive a representation of the input waveform;
a period determination subsystem configured to perform an iterative process to determine the variable period of the input waveform, the iterative process comprising;
selection of an estimated window length;
determination of an autocorrelation value based on the estimated window length;
determination of an adjustment value to the window length to identify a maximum of the autocorrelation value; and
determination of the variable period based on the window length associated with the maximum of the autocorrelation value; and
a control action subsystem configured to implement a control action based on the variable period of the input waveformwherein the period determination subsystem is further configured to perform the iterative process to track changes in the variable period of the input waveform.
2 Assignments
0 Petitions
Accused Products
Abstract
Disclosed herein are systems and methods for estimating a period and frequency of a waveform. In one embodiment, a system may comprise an input configured to receive a representation of the input waveform. A period determination subsystem may perform an iterative process to determine the variable period of the input waveform. The iterative process may comprise selection of an estimated window length, determination of an autocorrelation value based on the estimated window length, determination of an adjustment value to the window length to identify a maximum of the autocorrelation value; and determination of the variable period based on the window length associated with the maximum of the autocorrelation value. The period determination subsystem may perform the iterative process to track changes in the variable period of the input waveform. A control action subsystem may implement a control action based on the variable period of the input waveform.
54 Citations
20 Claims
-
1. A system configured to determine a variable period of an input waveform, the system comprising:
-
an input configured to receive a representation of the input waveform; a period determination subsystem configured to perform an iterative process to determine the variable period of the input waveform, the iterative process comprising; selection of an estimated window length; determination of an autocorrelation value based on the estimated window length; determination of an adjustment value to the window length to identify a maximum of the autocorrelation value; and determination of the variable period based on the window length associated with the maximum of the autocorrelation value; and a control action subsystem configured to implement a control action based on the variable period of the input waveform wherein the period determination subsystem is further configured to perform the iterative process to track changes in the variable period of the input waveform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for determining a variable period of an input waveform, the method comprising:
-
receiving a representation of the input waveform; and performing an iterative process to determine the variable period of the input waveform, the iterative process comprising; selecting an estimated window length; determining an autocorrelation value based on the estimated window length; determining an adjustment value to the window length to identify a maximum of the autocorrelation value; and determining the variable period based on the window length based on the window length associated with the maximum of the autocorrelation value; a control action subsystem configured to implement a control action based on the period of the input waveform; wherein the period determination subsystem is further configured to perform the iterative process to track changes in the variable period of the input waveform. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
-
20. A system configured to monitor a periodic waveform in an electrical power system and to determine a variable period of the periodic waveform, the system comprising:
-
an input configured to receive a representation of the periodic waveform; and a period determination subsystem configured to perform an iterative process to determine the variable period of the periodic waveform, the iterative process comprising; selection of an estimated window length; determination of an autocorrelation value based on the estimated window length; determination of an adjustment value to the window length to identify a maximum of the autocorrelation value; and determination of the variable period based on the window length associated with the maximum of the autocorrelation value; a periodicity determination subsystem configured to evaluate a periodicity of the periodic waveform and to provide a measurement quality indicator based on the periodicity of the input waveform for each of a corresponding plurality of values of the variable period; a control action subsystem configured to selectively disconnect a load connected to the electric power distribution system when the variable period exceeds a threshold; wherein the period determination subsystem is further configured to selectively discard values of the variable period when the measurement quality indicator is below a threshold.
-
Specification