The present invention discloses a method for determining the amplitude and phase of a stratified current of an overhead wire, the method comprising the following steps: S1, determining the specification, the size and main technical parameters of a wire; S2, calculating mutual inductances between conductors within a single-phase wire and the self-inductance thereof; S3, calculating mutual inductance reactance between conductors within the single-phase wire of a three-phase system and the self-inductance reactance thereof; and S4, calculating the distribution of currents in each layer. The method takes into account the magnetic field coupling effect between conductors within a wire, so as to accurately calculate the current flowing through conductors in each layer within the wire, and accurately reflect a phase relationship between conductors in each layer.

The present invention discloses a method for determining the amplitude and phase of a stratified current of an overhead wire, the method comprising the following steps: S1, determining the specification, the size and main technical parameters of a wire; S2, calculating mutual inductances between conductors within a single-phase wire and the self-inductance thereof; S3, calculating mutual inductance reactance between conductors within the single-phase wire of a three-phase system and the self-inductance reactance thereof; and S4, calculating the distribution of currents in each layer. The method takes into account the magnetic field coupling effect between conductors within a wire, so as to accurately calculate the current flowing through conductors in each layer within the wire, and accurately reflect a phase relationship between conductors in each layer.

An electronic circuitry is proposed. The electronic circuitry comprises a directional coupler comprising a first port configured to receive an input signal from a signal source, a second port configured to output the input signal for transmission to a load, a third port configured to output a forward signal based on the input signal, and a fourth port configured to output a reverse signal based on a reflection of the input signal received at the second port. The electronic circuitry further comprises a Time-to-Digital converter, TDC, coupled to the third port and the fourth port. The TDC is configured to determine a phase difference between the forward signal and the reverse signal.

An example circuit includes: a transmitter configured to transmit a clock pattern based on a transmit clock; a receiver, coupled to the transmitter, configured to sample the clock pattern based on a receive clock to generate a bit pattern, where there is a non-zero frequency difference between the transmit clock and the receive clock; a phase interpolator (PI) configured to add a phase shift to a source clock to supply one of the transmit clock or the receive clock; and a test circuit configured to apply adjustments to the phase shift over a time period and determine a phase distribution of the PI based on changes in the bit pattern over the time period.

A method executable by a computer processor is provided for determining stability of non-linear radio frequency (RF) circuit. The method includes identifying key devices of the RF circuit which open feedback loops when turned off; defining a generalized Bode's return ratio matrix with respect to the key devices over a range of small signal frequencies at a large signal operating point; determining stability margins for gain and phase of the RF circuit based on eigenvalues of the Bode's return ratio matrix; and determining overall stability of RF circuit using the Nyquist locus of a normalized determinant function based on the determinant of the generalized Bode's return ratio matrix.

A method executable by a computer processor is provided for determining stability of non-linear radio frequency (RF) circuit. The method includes identifying key devices of the RF circuit which open feedback loops when turned off; defining a generalized Bode's return ratio matrix with respect to the key devices over a range of small signal frequencies at a large signal operating point; determining stability margins for gain and phase of the RF circuit based on eigenvalues of the Bode's return ratio matrix; and determining overall stability of RF circuit using the Nyquist locus of a normalized determinant function based on the determinant of the generalized Bode's return ratio matrix.

A digital measurement system includes an oscillator, a mixer, and a controller coupled to each other. The oscillator provides a reference signal having a second frequency. The mixer generates a down-converted signal based on the output signal and the reference signal. The controller then determines a characteristic of the output signal (e.g., frequency or phase) based on the down-converted signal. An analog measurement system includes a filter having a center frequency, a rectifier, and a controller. The filter filters the output signal and the rectifier rectifies the filtered signal. The controller samples the rectified signal and determines a characteristic of the output signal based on the level of the rectified signal. The reference signal controller may adjust a characteristic of the output signal based on the determined frequency and/or phase of the output signal.

A controller including a memory having computer-readable instructions stored therein; and a processor configured to execute the computer-readable instructions to: estimate a synthesized grid voltage vector angle at a terminal of an alternating current (AC) grid based on at least an adjusted angle, to generate Pulse Width Modulation (PWM) signals to control power switches of the AFE inverter based on at least the synthesized grid voltage vector angle, and to control the AFE inverter to exchange power between the AC grid and a load based on the PWM signals.

A controller including a memory having computer-readable instructions stored therein; and a processor configured to execute the computer-readable instructions to: estimate a synthesized grid voltage vector angle at a terminal of an alternating current (AC) grid based on at least an adjusted angle, to generate Pulse Width Modulation (PWM) signals to control power switches of the AFE inverter based on at least the synthesized grid voltage vector angle, and to control the AFE inverter to exchange power between the AC grid and a load based on the PWM signals.

Phase detector circuitry includes oscillator circuitry, edge detection and correction circuitry, sampler circuitry, and adder circuitry. The oscillator circuitry is configured to provide a sawtooth oscillator signal. The edge detection and correction circuitry is configured to receive an in-phase signal and a quadrature signal, provide an edge detection signal during each edge of the in-phase signal and the quadrature signal, and provide an edge correction signal based on whether the edge is in the in-phase signal or the quadrature signal and whether the edge is a rising edge or a falling edge. The sampler circuitry is configured to sample the sawtooth oscillator signal in response to the edge detection signal. The adder circuitry is configured to subtract the edge correction signal from the sampled sawtooth oscillator signal to provide a phase estimate signal.