The present disclosure provides a primary frequency modulation method for a wind turbine, which may include: detecting a current frequency of a power grid; determining an instruction value of a power change amount for a primary frequency modulation by a first determining process when the current frequency of the power grid is less than a standard frequency of the power grid, wherein the first determining process may include: determining a reference value of the power change amount for the primary frequency modulation based on the current frequency; and when it is determined that currently there is an active power headroom for the wind turbine, comparing the reference value with a current active power headroom value of the wind turbine and determining the instruction value of the power change amount for the primary frequency modulation; and performing the primary frequency modulation based on the instruction value of the power change amount.

Provided is a power supply abnormality detection circuit capable of detecting a power supply abnormality using a logic circuit.

The power supply abnormality detection circuit includes a preset first dividing circuit part dividing a frequency of an input clock signal by a frequency of a first ratio and output the divided frequency, a second dividing circuit part dividing a frequency of the input clock signal by the frequency of the first ratio when a power supply voltage is a normal voltage, and dividing a frequency of an input signal by a frequency of a second ratio different from the first ratio and outputting the divided frequency when the power supply voltage is an abnormal voltage, and a comparison circuit part performing comparison of two signals of an output signal of the first dividing circuit part and an output signal of the second dividing circuit part.

A C/N ratio detection circuit includes a voltage detector, an averaging section, a time variation range calculator, and a C/N ratio calculator. The voltage detector measures an input voltage of a signal. The averaging section calculates an average of the input voltage over a predetermined time. The time variation range calculator calculates a time variation range of the input voltage over the predetermined time. The C/N ratio calculator calculates a C/N ratio of the signal by using the average and time variation range of the input voltage.

In systems, such as sensor systems, an output signal of the system (e.g. output of the sensor corresponding to a sensed characteristic) can be generated and provided. In response to a detected error, the output signal can be adjusted to generate an error indication signal pulse to indicate that an error has been detected. The output signal can then be adjusted to return to a signal level corresponding to the sensed characteristic. In response to the error being resolved, an error resolution signal pulse can be generated.

A method and device for determining the location-dependent pulse responses in signal transmission from a transmitter in a transmission volume to a receiver in a reception volume, wherein either the transmitter or the receiver is a device fixed in a predetermined location and the other is a movable device includes: continuously emitting a band-limited signal by the transmitter; continuously capturing the signal and recording the signal with time indexing by the receiver; moving the movable device during the emission and capturing of the signal along a trajectory within the transmission or reception volume while continuously capturing the location coordinates of the movable device and recording the location coordinates with time indexing; and numerically solving a linear system of equations, the unknowns of which system of equations represent the pulse responses at discrete sampling points in the transmission or reception volume associated with the movable device.

A method includes reading first and second timer count values from a timer, wherein the first timer count value is associated with a first time point and the second timer count value is associated with a second time point, calculating a difference between the first and the second timer count values, and determining whether the difference is within a range, wherein the range is based on a desired executing frequency to perform a computing task, a variation of the desired executing frequency, and a timer frequency. Further, based on the difference not being within the range, the method includes setting an error flag value to be true and incrementing an error count value.

An idle tone dispersion device outputs a frequency delta-sigma modulation signal obtained by using either one of a reference signal and a measured signal to perform frequency delta-sigma modulation of the other and dispersing an idle tone. The idle tone dispersion device includes n (n is any natural number equal to or larger than 2) frequency delta-sigma modulation sections and an adder configured to add up output signals of the n frequency delta-sigma modulation sections and output the frequency delta-sigma modulation signal. Each of the n frequency delta-sigma modulation sections uses either one of the reference signal and the measured signal to perform the frequency delta-sigma modulation of the other. At least one of the reference signal and the measured signal includes jitter including a frequency component higher than a frequency of an idle tone of an output signal of the frequency delta-sigma modulation section.

A detection device includes: a frequency property acquisition unit that acquires a frequency property when an alternating-current signal is input to at least two conductive bodies provided on a fiber sheet; and a detection signal output unit that outputs a detection signal when the frequency property acquisition unit acquires a predetermined frequency property.

A method for identifying frequently occurring waveform patterns in time series comprises segmenting each of one or more time series into a plurality of subsequences. Further, a subsequence matrix comprising each of the plurality of subsequences is generated. Further, the subsequence matrix is processed to obtain a candidate subsequence matrix comprising a plurality of non-trivial subsequences. Further, the plurality of non-trivial subsequences is clustered into a plurality of spherical clusters of a predetermined diameter. Further, a plurality of sub-clusters for each of one or more spherical clusters is obtained based on a mean of each of the plurality of non-trivial subsequences present in the spherical cluster. Further, one or more frequent waveform clusters, depicting frequently occurring waveform patterns, are ascertained from amongst the one or more spherical clusters based on a number of non-trivial subsequences present in each of the plurality of sub-clusters of the spherical cluster.

A MEMS device may output a signal during operation that may include an in-phase component and a quadrature component. An external signal having a phase that corresponds to the quadrature component may be applied to the MEMS device, such that the MEMS device outputs a signal having a modified in-phase component and a modified quadrature component. A phase error for the MEMS device may be determined based on the modified in-phase component and the modified quadrature component.