561 results about "Zero phase" patented technology

The system makes it possible to monitor various electrical variables by using a simple structure at low cost with ease and with high reliability by a circuit breaker which jointly includes a current transformer to detect current, a transformer to detect voltage, and a zero-phase current transformer to detect leakage current, in addition to the switch controller to perform the basic function of the circuit breaker. Moreover, the system also provides a function to display various measured values, obtained as described above, by a display unit that can be detached and installed separately from the measuring section to display data sent in digital form by data transmission.

Methods of compensating for radial incoherence in servo information that is read from adjacent servo tracks that have a phase offset relative to one another on a data storage disk of a disk drive are provided. While a transducer is seeking to a target track, the transducer generate a servo information signal that has a first component from servo information read from a first servo track on the disk and a second component from servo information read from a second servo track that is radially adjacent to the first servo track. The servo information in the first and second servo tracks are offset by a non-zero phase error relative to one another and are in a same servo sector on the disk. The servo information signal is sampled to generate a series of sampled servo values. A phase error of a group of the sampled servo values is determined. The sampled servo values are compensated in response to the determined phase error to generate compensated servo values with at least reduced phase error.

In compensating for unbalanced voltages of three-phase AC, instantaneous values of wye-phase voltages 120° out of phase with each other are obtained from line voltages using a centroid vector operation, symmetrical component voltages of three-phase balanced system are obtained from the instantaneous values of wye-phase voltages, a compensation signal to compensate unbalanced voltages of three-phase AC is generated from zero-phase-sequence voltage of symmetrical component voltages is generated, wye-phase voltages 120° out of phase, the unbalanced voltages of which are compensated, are obtained from the compensation signal and the symmetrical component voltages, a control signal of a PWM conversion is generated based on the compensated wye-phase voltage compensated, and the unbalanced voltages of three-phase AC are compensated. The amount of time to compensate the three-phase unbalanced voltages required for detecting an unbalance of voltages and generating a control signal can be shortened.

A phased antenna arrangement and a method for estimating the calibration ratio of an active phased antenna having a plurality of phased array antenna elements are described. The phased antenna arrangement includes a plurality of antenna elements, a plurality of receiving channels, an injection unit for injection of calibrating signals into the receiving channels, a point RF-source, located in a far field zone, a distance measurement unit, an amplitude and phase measurement unit and a data processing unit. The method comprises injecting an internal calibrating signal having a known amplitude and phase to each antenna element. An external calibration signal from a stationary RF-source is sequentially injected to all of the phased array antenna elements so that different phases of the external calibration signal arrive at each of the antenna elements. The differences in phases of the external calibration signal reaching the antenna elements are compensated so as compute an effective signal amplitude that would reach all of the antenna elements at zero phase difference. Calibration ratio is calculated as the ratio between the amplitude of the internal calibrating signal to the effective signal amplitude of the external calibration signal.

Linear predictive speech coding system with classification of frames and a hybrid coder using both waveform coding and parametric coding for different classes of frames. Phase alignment for a parametric coder aligns synthesized speech frames with adjacent waveform coder synthesized frames. Zero phase alignment of speech prior to waveform coding aligns synthesized speech frames of a waveform coder with frames synthesized with a parametric coder. Inter-frame interpolation of LP coefficients suppresses artifacts in resultant synthesized speech frames.

According to one embodiment of the invention, a 16-QAM optical modulator has a Mach-Zehnder modulator (MZM) coupled to a drive circuit that drives the MZM based on two electrical binary signals. The output of the MZM corresponds to an intermediary constellation consisting of four constellation points arranged on a straight line in the corresponding in-phase/quadrature-phase (I-Q) plane. Two of these constellation points correspond to a zero phase, and the remaining two constellation points correspond to a phase of π radian. The 16-QAM optical modulator further has a phase shifter that modulates the output of the MZM based on two additional electrical binary signals. The resulting optical output signal corresponds to a star 16-QAM constellation, which is produced by incremental rotation of the intermediary constellation.

A composite electric circuit breaker, and method thereof, is configured to detect signals regarding arc faults, overcurrent, and earth leakage. Arcs and electric currents are detected by a current transformer and earth leakage is detected by a zero phase current transformer. A variation of electric current, the number of arcs which are generated per a unit time, a present electric current value, and electric current earth leakage are combined to judge whether arc faults occur to then interrupt an electric power supply. Temperature is measured on a printed circuit board, and if temperature rise occurs, the electric power supply is interrupted, and an interruption cause is displayed. Electric accidents and occurrence of fires are prevented simultaneously and more accurately. The interruption causes can be confirmed, analyzed and externally monitored through a network, to thus maximize efficiency of electric management.

An ECU detects an effective value and phase of a voltage from a commercial power supply, based on a voltage from a voltage sensor. Further, ECU generates a command current, which is a command value of current caused to flow through power lines and in-phase with the voltage of the commercial power supply, based on the detected effective value and the phase and on a charge/discharge power command value for a power storage device. Then, ECU controls zero-phase voltage of inverters based on the generated command current.

The invention relates to a self-adapting method for filtering vehicle dynamic shaft load signal, aiming to effectively eliminate weighing error due to vehicle dynamic load and remarkably improve the vehicle weighing accuracy. The invention processes the original shaft load signal by zero phase offset and low-pass filtering, so as to eliminate white noise interference and inhibit phase distortion of the shaft load signal during low-pass filtering process. The invention also adopts optimized cut-off to the original weighing signal by searching average value of extreme points of shaft load signal, so as to better inhibit gravitation impulse interference in the weighing signal. Further, the invention decomposes the weighing signal by empirical mode decomposition method, meanwhile, adopts end point continuation method in empirical mode decomposition, so as to eliminate end effect, effectively inhibit the generation of false mode and make the decomposed result relatively true. The invention eliminates low-frequency interference through empirical mode decomposition, so as to obtain true shaft load signal.

The invention relates to a time-frequency synchronization joint estimation method based on a multi-carrier receiver of a digital television media broadcast (DTMB) system. The method is characterized by comprising the following steps: step 1, carrying out frame header mode recognition and frame header position coarse estimation; step 2, generating a pseudorandom noise (PN) sequence A of a zero phase matched with the frame header mode by a local PN generator, and carrying out carrier frequency offset estimation by utilizing a step-variable frequency sweeping method; step 3, correlating received data with the PN sequence A after compensation carrier is subjected to large frequency offset, so as to estimate a serial number of a frame; generating a PN sequence B of a matched phase matched with the frame header mode, and then correlating the PN sequence B with the received data so as to obtain a frame header position fine estimation value; and step 4, carrying out self-correlation on the frame header position according to the frame header position fine estimation value so as to obtain a carrier frequency offset fine estimation value, and summarizing a carrier frequency large offset estimation value and the carrier frequency offset fine estimation value so as to obtain a final carrier frequency offset estimation value. In the invention, the time-frequency synchronization joint estimation method based on the multi-carrier receiver of the DTMB system is used, thereby facilitating the realization of share of operation data and parameters and reducing the arithmetic labor.

In a rotary electric system, a rotary electric machine is provided with an armature core and star-connected multiphase windings with a neutral point wound in the armature core. Each of the star-connected multiphase windings has a predetermined winding configuration that prevents, when a zero-phase current is supplied from a direct current power source to the star-connected multiphase windings via the neutral point, a zero-phase magnetic flux created in the armature core based on the zero-phase current flowing in each phase winding of the star-connected multiphase windings from being cancelled out by a zero-phase magnetic flux created in the armature core based on the zero-phase current flowing in another one phase winding of the star-connected multiphase windings.

A measurement method is disclosed for measuring the resistance component leakage current included in the leakage current and the resistance value that is an insulation resistance to monitor the insulation state of a distribution system. The signal waveform of at least one AC cycle is sampled in the resistance component leakage current measurement from the leakage current signal and the voltage signal of a current transformer of target measurement circuit, and the resistance component leakage current is measured by dividing the average of integrated value of the instantaneous leakage current values and the instantaneous voltage values by the square root of average of squared instantaneous voltage values. A zero-cross detecting circuit for detecting a voltage zero-crossing point of the target measurement circuit and outputting a sampling start signal is provided, voltage digital data of the sine wave form whose effective value is 1 and the output signal of the zero-phase current transformer are sampled, and the products of multiplication are averaged by synchronizing the sampled output signal value and the voltage digital data to obtain an active leakage component current of leakage currents.

The invention discloses a leakage circuit breaker which has a simple and small structure of a test circuit and can simultaneously perform accurate leakage tests. As a power supply circuit for supplying power to the leakage detection circuit in the leakage circuit breaker, a power supply circuit with a constant current circuit that converts the AC current supplied from the main circuit into a DC current and supplies a constant DC current to the leakage detection circuit is used, and the test resistance The elements are arranged in series in the circuit connecting the main circuit and the AC input end of the current stabilizing circuit, and the test coil of the zero-phase converter is connected to both ends of the resistance element through a test switch to form a leakage test circuit.

A branch wire L5 from the voltage detection circuit 14 is inserted in the zero-phase-sequence current transformer ZCT in the direction from the load side to the external power supply side. For this configuration, the zero-phase-sequence current transformer ZCT is to detect unbalance of the sum of current flowing in the first and second conductive wires L1, L2 and the current flowing in the branch wire L5. Therefore, the present invention can accurately detect occurrence of electrical leakage.

Disclosed is a gas ultrasonic flowmeter intermittent excitation and signal processing system based on an adjacent peak maximum difference value. An ultrasonic transmitting transducer is excited through intermittent excitation signals (continuous non-coding excitation signals are transmitted one time, and then transmitted again after a certain period of time), and an ultrasonic signals are generated; when a receiving transducer receives ultrasonic signals, the signals are converted into echo signals; then, zero phase filtering is performed on the received echo signals, a characteristic wave corresponding to the maximum difference value of adjacent peaks in the echo signals is found, a mean value of eight zero crossing points behind the characteristic waves is adopted as a characteristic point, ultrasonic signal down flow and reverse flow transmitting time is determined, and the gas flow is calculated.

The invention discloses a low-orbit/middle-orbit double-layer satellite optical network structure system. Global coverage low-orbit satellite constellation designed on the basis of a coverage zone method and middle-orbit satellite constellation form a double-layer satellite optical network structure system. The system is connected with at least 76 satellites, wherein, a low-orbit satellite layer is provided with at least 7 orbits, and each orbit is connected with at least 10 satellites; a middle-orbit satellite layer is composed of an outer orbit and an inner orbit, wherein, the outer orbit is respectively connected with the satellites, and the inner orbit is respectively connected with the satellites. The calculation method is as follows: calculating the radius theta of a single satellite covering circle; calculating the halfangle psi of the covering zone; calculating delta B; calculating alpha'; calculating sin alpha; and calculating the distribution of P orbits on the equator. The structure is stable topological structure, the changes of inter-satellite links pitch angle and azimuth angle are smaller than the changes of the inter-satellite links pitch angle and the azimuth angle of the non-zero phase constellation, satellite switch is reduced, satellite-carried resources are saved, and management of the low-orbit satellite layer is effectively strengthened; the middle-orbit satellite constellation is least affected by space radiation, and the system life cycle is lengthened.

The present invention disclosed herein is an electric leak breaker for self-test. The electric leak breaker for self-test comprises power supply lines for connecting a power source supply with a load; a zero-phase current transformer installed on the power supply lines and for sensing a current difference between the power supply lines; a leakage current detecting unit connected to the zero-phase current transformer for detecting whether a leakage current occurs to generate a detection signal; a driving unit for making the power supply lines broken when a critical voltage or a voltage higher than the critical voltage is provided; and a self-test unit for periodically inducing the leakage current at the power supply lines to test whether the leakage detecting unit is normally operating, and for providing a lower voltage than the critical voltage to the driving unit to test whether the driving unit is normally operating in a self-test operation. According to the present invention, it is possible to periodically test the electric leak breaker as well as to overcome an inconvenience to push a reset button.