Methods, devices, and systems for coherent time-gated residual spur characterization and correction in signal analyzers. In some cases, the method includes: displaying a signal on the display of the signal analyzer that is present without an input signal being provided to an input of the signal analyzer; establishing a predetermined amplitude threshold above which energy spikes in the signal being displayed on the display of the signal analyzer are considered spurious; automatically identifying one or more spurious energy spikes in the signal being displayed on the display of the signal analyzer based on the predetermined amplitude threshold; and automatically reducing or removing the one or more spurious energy spikes from the signal being displayed on the display of the signal analyzer. The method can be performed using one or more processors, application specific integrated circuits (ASICs), field-programmable gate array (FPGA), or other circuitry on any suitable signal analyzer.

A reliable method and apparatus for communications over AC power lines that may have substantial interference is disclosed. A controller can be plugged into an AC outlet and communicate with a device plugged into any other AC outlet over the power lines within the facility. The controller may perform an analysis of the interference that is present on the power lines that run throughout the facility. In some cases, the particular path for power line signals can be selected to reduce the potential for interference. In some cases, the controller has a front end that comprises a Fast Fourier Transform (FFT) module and a neural network. In addition, devices under the control of the controller may have neural networks that can be used in combination to form a collaborative neural network.

A frequency detection circuit may include a pulse generator configured to generate a pulse signal having a pulse width proportional to a cycle of a periodic wave to be measured; a low pass filter configured to selectively allow the pulse signal to pass therethrough; and a determination circuit configured to generate a frequency detection signal based on the pulse signal having passed through the low pass filter.

A frequency detection circuit may include a pulse generator configured to generate a pulse signal having a pulse width proportional to a cycle of a periodic wave to be measured; a low pass filter configured to selectively allow the pulse signal to pass therethrough; and a determination circuit configured to generate a frequency detection signal based on the pulse signal having passed through the low pass filter.

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 diagnostic method and a diagnostic system for an electrochemical energy storage cell, and a vehicle including the diagnostic system. An electrical current due to an electrical connection between the energy storage cell and a central load is modulated at a first excitation frequency and is measured centrally. An electrical voltage at the energy storage cell is measured and a first impedance value is determined based on the electrical current and the electrical voltage. Also, a previously-known electrical current due to an electrical connection between the energy storage cell and a predefined cell-individual load is modulated at a second excitation frequency. The electrical voltage occurring at the energy storage cell is measured and a second impedance value is determined based on the previously-known electrical current and the electrical voltage. Diagnostic information is determined and output based on a comparison of the first impedance value with the second impedance value.

A diagnostic method and a diagnostic system for an electrochemical energy storage cell, and a vehicle including the diagnostic system. An electrical current due to an electrical connection between the energy storage cell and a central load is modulated at a first excitation frequency and is measured centrally. An electrical voltage at the energy storage cell is measured and a first impedance value is determined based on the electrical current and the electrical voltage. Also, a previously-known electrical current due to an electrical connection between the energy storage cell and a predefined cell-individual load is modulated at a second excitation frequency. The electrical voltage occurring at the energy storage cell is measured and a second impedance value is determined based on the previously-known electrical current and the electrical voltage. Diagnostic information is determined and output based on a comparison of the first impedance value with the second impedance value.

A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector filters the proximity reading through three low pass filters using a three different time constants to generate three filtered readings. While the proximity detector is in the no material present state, the proximity detector will enter the material present state when the second filtered reading is less than the difference between the first filtered reading and the falling threshold. While the proximity detector is in the material present state, the proximity detector enters the no material present state when the third filtered reading is greater than the sum of the first filtered reading and the rising threshold.

A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector filters the proximity reading through three low pass filters using a three different time constants to generate three filtered readings. While the proximity detector is in the no material present state, the proximity detector will enter the material present state when the second filtered reading is less than the difference between the first filtered reading and the falling threshold. While the proximity detector is in the material present state, the proximity detector enters the no material present state when the third filtered reading is greater than the sum of the first filtered reading and the rising threshold.

A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector filters the proximity reading through three low pass filters using a three different time constants to generate three filtered readings. While the proximity detector is in the no material present state, the proximity detector will enter the material present state when the second filtered reading is less than the difference between the first filtered reading and the falling threshold. While the proximity detector is in the material present state, the proximity detector enters the no material present state when the third filtered reading is greater than the sum of the first filtered reading and the rising threshold.