An input circuitry for receiving electrode signals comprises: a plurality of channels for providing a multiplexed electrode signal input, each channel comprising a multiplexing switch for selecting one channel at a time, and an input transistor configured to be connected to an electrode, wherein the input transistor is configured to receive an electrode signal at a gate; and a reference input transistor, which is configured to be connected to a reference voltage at a gate; wherein an electrode signal received at a selected channel together with the reference voltage form input signals to an instrumentation amplifier; wherein the input circuitry is configured such that the input transistor of the selected channel forms part of a first flipped voltage follower and the reference input transistor forms part of a second flipped voltage follower.

Embodiments of the present disclosure may monitor and adjust a sampling rate of an ADC for converting the power signal to a digital signal, locking onto the phase and frequency of the power signal. This technique may make the sampling process coherent relative to the power signal. Properties of the power signal, such as phase, frequency, and magnitude, may be extracted relative to an idealized power signal.

An apparatus and method for detecting leakage current in a non-volatile memory array. A reference current is connected to a leakage detection circuit. A reference code is determined for the leakage detection circuit coupled to a switching circuit. The reference code establishes a leakage current threshold. The reference current is disconnected from the leakage detection circuit and the switching circuit. Next, the leakage detection circuit is connected to a set of word lines of a storage block of a non-volatile memory array by way of the switching circuit. A memory current is generated within the set of word lines. A leakage code is determined for the set of word lines representing leakage current from the word lines in response to the memory current. The leakage code is compared with the reference code. If the leakage code exceeds the reference code, the storage block is deemed unusable.

A method for performing synchrophasor estimation of an input signal, whereby the input signal is a sinusoidal power system voltage or current signal, comprising: a. Periodic sampling of a continuous time-domain waveform, consisting of a power system voltage or current signal, to obtain a discrete time-domain function; b. Transforming a discrete time-domain function to a discrete frequency-domain function; c. Estimating from the discrete frequency-domain function the instantaneous parameters of a synchrophasor of the sampled continuous time-domain waveform, the instantaneous parameters comprising a frequency, an amplitude and a phase angle. The method is directed to an improvement of the enhanced IpDFT-based synchrophasor estimation which takes into account interharmonic tones.

An impedance sensing circuit includes first and second current sources and first and second bias current sources that are appropriately coupled to first and second resistors. The impedance sensing circuit also includes a comparator that compares a first voltage based on the first terminal of the first resistor to a second voltage based on the first terminal of the second resistor to generate a comparator output signal. Either the comparator output signal or a digital signal based on the comparator output signal operates to regulate the current signals output from the first and second current sources so that the first voltage is same as the second voltage. The comparator output signal and the digital signal is representative of a difference between the first voltage and the second voltage that is based on an impedance difference between the first resistor and the second resistor.

A partial discharge detection apparatus includes low-speed and high-speed AD converters. The low-speed AD converter converts an analog signal of an AC waveform flowing through a power cable into a digital signal. The high-speed AD converter converts an analog signal of a partial discharge current into a digital signal. The analog signal is in a plurality of Nyquist frequency domains defined for each of two different types of sampling frequencies. The partial discharge is detected by a partial-discharge-detection digital signal processing unit based on the maximum value or the sum of a current value obtained from the digital signal of the partial discharge current obtained by the conversion of the high-speed AD converter, for each phase of the AC waveform, which is obtained from the digital signal of the AC waveform flowing in the power cable. The digital signal is obtained by the conversion of the low-speed AD converter.

A real-time power monitoring method executable by an electronic device, comprising: performing an ADC calibration operation to a voltage of a first battery of the electronic device; calculating and forming a diagonal line for the first battery; determining whether the comparison result between a gain and an offset and an optimum gain and an optimum offset is located with a preset error range; if the comparison result is located with the preset error range, determining that the voltage calibration for the first battery is successful; and, if the comparison result is located outside the preset error range, determining that the voltage calibration for the first battery is unsuccessful, analyzing and fixing the first battery and for re-performing the ADC calibration to the first battery.

Disclosed is a high voltage signal and low voltage signal sampling and transmission system based on a high voltage MCU, including a sampling unit, a high voltage processing unit, a communication unit and a low voltage processing unit. The sampling unit includes a bus voltage sampling module, a phase voltage detection module and an IGBT temperature detection module. The high voltage processing unit adopts the high voltage MCU, and the high voltage MCU is configured to perform state monitoring and analog-to-digital conversion on the three-way analog detection signals, and output a digital signal to the communication unit; the communication unit adopts an isolated communication unit to transmit the three-way digital signal converted by the high voltage MCU to the low voltage processing unit; the low voltage processing unit adopts a low voltage MCU to realize sampling and communication of high and low voltage sampling signals.

Disclosed are a current calibration method and a system by compensating a voltage of a current sensor, the method comprises: obtaining a power supply sampling voltage V.sub.cc by performing ADC sampling on a power supply of the current sensor, and obtaining a ground plane sampling voltage V.sub.GND_sensor by performing analog-to-digital converter (ADC) sampling on a voltage of the ground plane; sampling a current of the current sensor to obtain a sensor sampling voltage V.sub.out, and compensating the voltage of the current sensor to calibrate the sensor sampling voltage V.sub.out, wherein the calibrated sensor sampling voltage V.sub.out_correct is:

[00001]$V_{\mathrm{out\_correct}}=\frac{\left(V_{\mathrm{out}}-V_{\mathrm{GND\_sensor}}\right).Math.V_{\mathrm{nom}}}{V_{\mathrm{cc}}-V_{\mathrm{GND\_sensor}}}$

wherein V.sub.nom is a rated voltage of the power supply of the current sensor; and obtaining a calibrated sensor sampling voltage according to the calibrated sensor current value and a conversion coefficient of sampling voltage-current.

Systems and methods for improving identification of issues associated with detecting anomalous conditions (e.g., electrical transient voltages) in electrical systems are disclosed herein. The anomalous conditions may be difficult to discern, for example, due to metering constraints of Intelligent Electronic Devices (IEDs) responsible for identifying the anomalous conditions in the electrical systems. In one aspect of this disclosure, a method to automatically identify metering constraints of one or more IEDs in an electrical system includes capturing at least one energy-related waveform using at least one of the IEDs in the electrical system, and processing electrical measurement data from, or derived from, the at least one energy-related waveform to identify anomalous characteristics in the electrical system. The anomalous characteristics may be indicative of an anomalous condition in the electrical system, for example. In response to identifying anomalous characteristics in the electrical measurement data, an event constraint model is built based on or by using the identified anomalous characteristics. Once built, the event constraint model is analyzed to determine if the at least one energy-related waveform is being adequately captured by the at least one of the IEDs. In response to determining the at least one energy-related waveform is not adequately captured, one or more actions may be taken to address the capturing inadequacy.