Systems, devices, software, and methods of the present invention enable frequency-based signal power analyses in software suitable for signal with either stationary and non-stationary spectrums. The methods that may be used throughout various systems including transmitters receivers, repeater, controllers, monitors, etc. and in software simulators to enable various signal power calculations and analyses, such as frequency spectrum analysis, throughout operating systems and that may be consistently applied in system design and operation simulations in a wide range of applications, such as interference and spectrum monitoring or clearance, object tracking, transmission channel and noise analyses, radiated power analysis, signal boundary interference, satellite downlink signal identification, pulsed radar monitoring, audio detection and identification, lidar systems, sonar systems, etc.

A measurement data based method for identifying wind turbine generators which cause sub-synchronous oscillations in a complex power system has a theoretical foundation of the open-loop modal resonance and the parallel filter design. The advantages of the present invention are as follows. 1) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system using measurement data instead of parametric model. Hence, it simplifies the computation and reduces the modeling cost effectively. 2) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system precisely with reduced amount of measurement data, reducing the cost of hardware and data measurement effectively. 3) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system based on the open-loop modal resonance theory.

A measurement data based method for identifying wind turbine generators which cause sub-synchronous oscillations in a complex power system has a theoretical foundation of the open-loop modal resonance and the parallel filter design. The advantages of the present invention are as follows. 1) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system using measurement data instead of parametric model. Hence, it simplifies the computation and reduces the modeling cost effectively. 2) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system precisely with reduced amount of measurement data, reducing the cost of hardware and data measurement effectively. 3) The present invention can identify the wind turbine generators which cause the SSOs in the complex power system based on the open-loop modal resonance theory.

Systems, apparatuses, methods and computer processes to separate and select frequency components of a signal in real time without phase delay by predicting or forecasting future values of the signal and using that forecast and past measurements in a noncausal zero-phase filtering algorithm are provided. The method of separating and selecting frequency components of a signal in real time without phase delay using a zero-phase filter, comprises obtaining past measurements of the signal; obtaining predicted values of the signal; and using the predicted values of the signal and the past measurements of the signal as components of an input signal in a noncausal zero-phase filtering algorithm for a zero-phase filter, the zero-phase filter producing an output signal.

Systems, apparatuses, methods and computer processes to separate and select frequency components of a signal in real time without phase delay by predicting or forecasting future values of the signal and using that forecast and past measurements in a noncausal zero-phase filtering algorithm are provided. The method of separating and selecting frequency components of a signal in real time without phase delay using a zero-phase filter, comprises obtaining past measurements of the signal; obtaining predicted values of the signal; and using the predicted values of the signal and the past measurements of the signal as components of an input signal in a noncausal zero-phase filtering algorithm for a zero-phase filter, the zero-phase filter producing an output signal.

A signal processing method generates a time-frequency domain representation of an input signal for the purpose of signal detection, signal display, and application of filtering operations, such as sample accurate spectral editing. The method may include receiving an input signal in the time domain in a processor. The input signal may include a plurality of transform frames. The input signal is transformed into the frequency domain using a frequency transform. Time-frequency matrices are generated from the frequency transform. Crossfrequency phase coupling is applied between adjacent frequency bins to introduce synchronization between adjacent frequencies and to generate smoothed time-frequency matrices with sample-accurate frequency magnitudes. The frequency information can be edited in the time-frequency domain specific to a single sample of the transform frame to alter unwanted signal features. A modified time domain representation of the edited input signal can be generated from the modified time-frequency matrices.

A signal processing method generates a time-frequency domain representation of an input signal for the purpose of signal detection, signal display, and application of filtering operations, such as sample accurate spectral editing. The method may include receiving an input signal in the time domain in a processor. The input signal may include a plurality of transform frames. The input signal is transformed into the frequency domain using a frequency transform. Time-frequency matrices are generated from the frequency transform. Crossfrequency phase coupling is applied between adjacent frequency bins to introduce synchronization between adjacent frequencies and to generate smoothed time-frequency matrices with sample-accurate frequency magnitudes. The frequency information can be edited in the time-frequency domain specific to a single sample of the transform frame to alter unwanted signal features. A modified time domain representation of the edited input signal can be generated from the modified time-frequency matrices.

A signal processing method and a material testing machine are provided. A reference function processing part includes a data interval generation part for cutting out input signal from a load cell into time-domain data interval by cutting out the input signal of a predetermined time length, a reference function determining part for determining a reference function to be used in a transform process, and a transform part for transforming the interval data using the reference function. Considering the approximately straight lines near the two ends of the data interval, the reference function is a third degree polynomial function with tangents overlapping with the approximately straight line at both ends of the data interval.

A signal processing method and a material testing machine are provided. A reference function processing part includes a data interval generation part for cutting out input signal from a load cell into time-domain data interval by cutting out the input signal of a predetermined time length, a reference function determining part for determining a reference function to be used in a transform process, and a transform part for transforming the interval data using the reference function. Considering the approximately straight lines near the two ends of the data interval, the reference function is a third degree polynomial function with tangents overlapping with the approximately straight line at both ends of the data interval.

A current detector and a detection unit are provided. The current detector is connected to at least one of drive current lines of a rotary machine. The detection unit performs an orthogonal detection on a main frequency detected by the current detector, and extracts a magnitude of a sideband wave. Then, a state of the rotary machine is diagnosed from the magnitude of the extracted sideband wave.