31 results about "Phase ordering" patented technology

In one embodiment of the invention, a phase selection unit for generating a recovered clock signal (SCLK), a phase select signal generator generates a phase select signals in response to a FWD signal and a BWD signal from a digital filter. The digital filter asserts the FWD signal if the phase of a SDIN (serial digital input) signal leads the phase of the recovered clock signal, and asserts the BWD signal if the phase of the SDIN (serial digital input) signal lags the phase of the recovered clock signal. A multiplexer receives a number of given clock signals arranged in a predetermined phase order and outputs selected first and second output clock signals, each being one of the given clock signals. A phase interpolator receives the selected first and second output clock signals from the multiplexer to generate the recovered clock signal having a phase that is phase interpolated between the phases of the first and second output clock signals.

The invention discloses a three-phase AC motor power phase-losing detection and phase-correcting method and device, which is characterized by the following: judging whether outer power is phase-losing and phase-sequence changing through detecting three-phase AC power phase-position sequence; avoiding error judgment for loop of the three-phase motor and solid relay; designing the device according to the character of microprocessor and digital signal processor.

The invention discloses a phase sequence detection circuit for a three-phase power supply, wherein the phase sequence detection circuit comprises a power supply signal collecting module (410) and a judging module (420). The judging module (420) comprises comparing units (421a-421c) and time delay units (422a-422c), and is configured as follows: a collected result signal of each phase is respectively compared with a desired voltage waveform signal by the comparing units (421a-421c); a compared result signal of each phase is output, respectively; the compared result signals are respectively received by the time delay units (422a-422c); the compared result signal of each phase is repeatedly detected in a predetermined delay time section, respectively; and subsequently, a phase sequence detection result signal of each phase is respectively output. The phase sequence detection circuit of the invention has the advantages of high timing precision, wide range of application, lighter load for both a CPU (Central Processing Unit) and software, and property for a non-real-time operating system.

The invention discloses a three-phase electro-magnetic double-salient-pole motor high-speed sensorless control strategy based on non-communicating phase terminal voltage coordinate transformation. The strategy includes: respectively detecting three-phase terminal voltage according to the feature that a three-phase electro-magnetic double-salient-pole motor has a zero crossing point in non-communicating reverse potential in an electric cycle, allowing the voltage to enter a digital controller to perform rotary coordinate transformation, consistent with the phase order of motor rotation, on the current upper tube communicating phase terminal voltage after the voltage is filtered by an RC filter, obtaining the rotary angle alpha ranging from 30 degrees to 60 degrees according to different rotation speeds, and judging the phase change points by detecting the zero crossing points of the current upper tube communicating phase terminal voltage after coordinate transformation. By the strategy, the defect that the reverse potential cannot be detected directly during high-speed operation is overcome, weight and size of the filter can be reduced, and the electro-magnetic features and mathematical models of the motor need not be known in advance. In addition, the strategy is applicable to three different chopping manners, and easy to implement.

The invention provides a three-phase alternating voltage phase sequence monitoring system, including: a step-down filtering and shaping circuit; a comparator circuit which compares a three-phase alternating voltage processed by the step-down filtering and shaping circuit with a reference voltage and outputs a three-channel comparison result; a logic circuit which detects a phase sequence of the three-phase alternating voltage according to the three-channel comparison result and outputs a judgment signal; a driving protection circuit which drives a relay according to the judgment signal; and a relay which generates an indication signal according to an output signal of the driving protection circuit, outputs a phase sequence correct indication signal when the phase sequence of the three-phase alternating voltage is correct, and outputs an alarm indication signal when the phase sequence of the three-phase alternating voltage is in disorder or a phase loss occurs. The three-phase alternating voltage phase sequence monitoring system provided by the invention detects the phase sequence of the three-phase alternating voltage, thereby driving the relay, and protecting safety of electric equipment, and effectively avoiding unnecessary loss brought by the problems of phase sequence disorder and phase loss; and at the same time, since the three-phase alternating voltage phase sequence monitoring system is integrated in a circuit module of a chip, the system is small in size, and the system is convenient to operate and high in detection precision.

The invention provides a phase sequence detection device and a phase sequence detection method. According to the embodiment of the invention, the phase sequence detection device comprises a waveform detection circuit for detecting respective waveforms of the line voltage of the first phase relative to the second phase and the line voltage of the second phase relative to the third phase of three-phase alternating-current power, and a signal processor which is used for detecting the phase sequence of the alternating current power or the occurrence of phase loss fault according to the time interval between the waveforms detected by the waveform detection circuit. According to the embodiment of the invention, the phase sequence detection can be conveniently, effectively and reliably realized through a software and hardware combination mode.

The invention provides a current tracking control method. For a hybrid rectifier including a three-level PWM boost rectifier, the current tracking control method comprises the steps of obtaining three-phase given current, acquiring three-phase input real-time current of the hybrid rectifier, sorting three-phase input phase sequences of the hybrid rectifier according to three-phase set duty ratio from small to big, obtaining the breakover time Tx, Ty and Tz of a three-phase switch in a working period according to a circuit structure of the hybrid rectifier, judging whether 0<Tx<Ts / 2, 0<Ty<Ts / 2 or 0<Tz<Ts / 2 is established or not; correcting the Tx, Ty or Tz; obtaining the three-phase duty ratio of the three-phase switch; respectively performing breakover or turnoff of the corresponding three-phase control switch according to the three-phase duty ratio after pulse width modulation so as to achieve current tracking. The current tracking control method has the advantages of being high power factor, low in harmonic distortion rate and the like and can be widely applied to the field of current tracking control.

The invention provides a method and device for automatically adjusting a phase sequence. The method comprises the following steps of 1) detecting a phase sequence of an inverter input three-phase AC voltage before a device is put into operation; 2) achieving phase locking according to a phase sequence of A, B and C, and controlling an inverter to start and run; and 3) automatically adjusting phaselocking when the phase sequence is not correct, achieving phase locking according to a phase sequence of A, C and B, and controlling the inverter to start and run according to the phase sequence of A, C and B. By the method, the problems of complicated self-adaptive adjustment process of the phase sequence and time delay in the adjustment process are solved.

The present invention relates to a three-phase electricity phase sequence judging method for judging the three-phase electricity phase sequence on the basis of the voltage vector u-tilde(k) in the current period and the voltage vector u-tilde(k-1) in the previous period. The phase sequence judging method has the low computational complexity and is simple so as to greatly ease the burden of a processor and improve the phase sequence detection efficiency. The three-phase electricity phase sequence judging method can be widely used under severe operation conditions such as loss of phase and input of harmonic wave, is simple and useful, has the strong anti-jamming capability, and can rapidly acquire the phase sequence information of three-phase electricity.

Provided is a method of selecting the optimal phase sequence arrangement mode of a one-tower double-circuit transmission line. According to the method, a one-tower double-circuit transmission line detailed simulation model is established based on an ATP / EMTP simulation platform, and phase sequence arrangement modes of which the negative sequence current imbalance is less than 5% are screened out according to the change in length of transmission lines. Moreover, a one-tower double-circuit transmission line outside-the-protected-area inter-phase short circuit fault model is built, the influence of the one-tower double-circuit transmission line phase sequence arrangement mode on misjudgment of a zero sequence power directional element in a relay protection device is evaluated according to transmission lines of different lengths, preferred sorting of negative sequence imbalance and preferred sorting of relay protection are comprehensively considered, and the optimal phase sequence arrangement mode is selected out. The engineering requirement that the negative sequence current imbalance of a newly-built one-tower double-circuit transmission line project should be less than 5% is met, and the problem that a zero sequence power directional element in a line protection device malfunctions due to the mode of conductor phase sequence arrangement is solved.

The invention discloses a phase sequence rapid measuring method based on a three-phase instantaneous point. According to the phase sequence rapid measuring method, an existing hardware basis of a system is utilized, a circuit is not additionally arranged, an instantaneous value relation of a three-phase system is utilized, and the phase sequence relation of the three-phase system can be rapidly judged by using a simple logical judgement relation according to a three-phase component instantaneous value relation of an optional ZCP (Zero Crossing Point) time in the three-phase system. Compared with the traditional independent phase sequence measuring method, the phase sequence rapid measuring method disclosed by the invention has the advantages that the calculation is simple, the judgement is rapid, a hardware circuit for independently measuring the phase sequence is not added, the response time is not higher than 1 / 6 work period, and the phase sequence rapid measuring method is very effective for a three-phase symmetrical system or an application occasion similar to the three-phase symmetrical system.

The invention relates to a phase sequence judging circuit, in particular to a phase sequence judging circuit based on an asymmetrical three-phase circuit theory. The invention mainly aims to provide a circuit scheme which has the characteristics of reliability, accuracy, quickness, conciseness and low cost and is used for judging the phase sequence in a low-voltage three-phase power supply system. The basic content of the invention refers to a circuit special for judging the phase sequence in a three-phase low-voltage power supply system constituted on the basis of an asymmetrical three-phase circuit theory. The phase sequence judging circuit is in a photoelectric coupler output form or a relay output form, and comprises an asymmetrical three-phase input loop, a bypass resistor, a diode rectifier bridge, a filtering capacitor, an LED (Light-Emitting Diode), a photoelectric coupler or a relay and the like, wherein the asymmetrical three-phase input loop consists of a capacitor and a resistor.

The invention relates to a three-phase three-wire phase voltage detection method, which can accurately restore phase voltage effective value according to line voltage real-time collected data through the steps of wire-to-phase algorithm, phase lock and reference voltage construction, amplitude separation and amplitude reconstruction and the like. The method can realize phase voltage detection of an unbalanced three-phase three-wire system, and can even realize out-phase detection of the three-phase three-wire system; and the method is simple and practical and high in anti-interference performance, and can obtain phase sequence information of three-phase power quickly.

The invention discloses a three-phase unit control circuit and a reverse phase protection state detection method thereof. The three-phase unit control circuit comprises a compressor (1), a reverse phase protector (4), a mainboard (5) and a display device, wherein the compressor (1) is connected with a three-phase power supply (3) by virtue of an alternating current contactor (2); the reverse phase protector (4) is arranged on a three-phase circuit between the compressor (1) and the three-phase power supply (3) and is used for detecting phase sequence of the three-phase power supply (3); the mainboard (5) is connected to the reverse phase protector (4) so as to acquire a state of the reverse phase protector (4) and controls power supply of the alternating current contactor (2) according to the state of the reverse phase protector (4); the display device is connected to the mainboard (5) and displays the state of the reverse phase protector (4). According to the three-phase unit control circuit disclosed by the invention, three-phase unit failure caused by phase sequence errors can be timely detected, and the failure repair efficiency is improved.

The invention relates to a phase sequence detector suitable for use with 3-phase pulsed motor driver signals and to a phase sequence detection method suitable to determine phase sequence and phase loss states in 3-phase variable frequency motor driver signals.

An MRI apparatus which performs MR imaging in an SSFP pulse sequence in which RF excitation is accomplished by a phase cycling method is caused; to collect data regarding all the frequency regions in a k-space in an SSFP pulse sequence in a first phase series out of a plurality of phase series; to collect data regarding low frequency regions in the k-space in the SSFP pulse sequence in the remaining phase series out of the plurality of phase series; to reconstruct an image by Fourier transform of the data regarding all the frequency regions collected in the SSFP pulse sequence in said first phase series; to generate frequency data of the k-space by inverse Fourier transform of said image; to separate said frequency data into data of the low frequency regions in the k-space and data of high frequency regions; to add data whose value is 0 to said separated data of the low frequency regions as substitute for the data of the high frequency regions; to add data whose value is 0 to said separated data of the high frequency regions as substitute for the data of the low frequency regions; to add data whose value is 0 to the data of the low frequency regions collected in the SSFP pulse sequence in the remaining phase series as substitute for the data of the high frequency regions; to reconstruct low space frequency images based on the low frequency regions to which said substitute data have been added; to reconstruct high space frequency images based on the high frequency regions to which said substitute data have been added; and to totally add said low space frequency images and said high space frequency images multiplied by a scaling factor.

The method for drawing the main busbar connection diagram between the dry-type distribution transformer and the low-voltage switchgear of the present invention relates to the conductive connection of the transformer. The drawing method determines the coordinate values ​​of the relevant parameters in the established XY coordinate system; the drawing method is written in the Visual C++ language. In the human-computer interaction interface, the data required for drawing is input into the computer. Determine the position and shape of each connected copper bar according to the input outlet method, the phase sequence of the input copper bar of the low-voltage switchgear and the coordinate value of each phase of the input copper bar of the low-voltage switchgear, and draw each connected copper bar. According to the coordinate values ​​of the low-voltage side copper bars of each phase of the dry-type distribution transformer, determine the position and shape of each phase outgoing copper bar of the dry-type distribution transformer, and draw the outgoing copper bars of each phase of the dry-type distribution transformer. The drawing method of the invention can significantly shorten the design cycle of the main busbar connection diagram between the dry-type distribution transformer and the low-voltage switchgear, improve the quality of the drawings, and meet the design requirements.

Disclosed is a method for connecting one-tower multiple-loop electric transmission lines and buses. The method includes that a simulation model of prestored one-tower multiple-loop electric transmission lines is obtained, and each of the one-tower multiple-loop electric transmission lines in the simulation model is respectively connected with a phase A, a phase B and a phase C of the buses through three circuit breakers; prestored phase sequence arrangement modes of the one-tower multiple-loop electric transmission lines are traversed to obtain a set of phase sequence arrangement modes; each circuit breaker is controlled according to the phase sequence arrangement modes, each of the one-tower multiple-loop electric transmission lines accesses to corresponding phases of each of the buses in the simulation model, and three-phase current imbalance indicators under steady state in the simulation model are calculated and stored; after the prestored phase sequence arrangement modes are traversed, a phase sequence arrangement mode corresponding to a minimum three-phase current imbalance indicator among the three-phase current imbalance indicators is determined; and connection between each of the one-tower multiple-loop electric transmission lines and the corresponding phases of each of the buses according to the determined phase sequence arrangement modes. The invention further provides a corresponding system for connecting the one-tower multiple-loop electric transmission lines and the buses. By the arrangement, efficiency of operation process for connecting the lines and the buses is improved.

The invention discloses a phase sequence rapid measuring method based on a three-phase instantaneous point. According to the phase sequence rapid measuring method, an existing hardware basis of a system is utilized, a circuit is not additionally arranged, an instantaneous value relation of a three-phase system is utilized, and the phase sequence relation of the three-phase system can be rapidly judged by using a simple logical judgement relation according to a three-phase component instantaneous value relation of an optional ZCP (Zero Crossing Point) time in the three-phase system. Compared with the traditional independent phase sequence measuring method, the phase sequence rapid measuring method disclosed by the invention has the advantages that the calculation is simple, the judgement is rapid, a hardware circuit for independently measuring the phase sequence is not added, the response time is not higher than 1 / 6 work period, and the phase sequence rapid measuring method is very effective for a three-phase symmetrical system or an application occasion similar to the three-phase symmetrical system.

The invention provides an electromagnetic induction power transmission system, which comprises a power base station and a ground cable laying system electrically connected with the power base station, wherein the power base station is used for converting a power supply of the power base station into N-phase high-frequency AC and outputting the N-phase high-frequency AC to the ground cable laying system, wherein N is greater than or equal to 2; the ground cable laying system comprises M cable loops which are surrounded by cables; the cable loops of different power supply phases are equal in quantity and N cable loops of the different power supply phases form one cable loop group; N cable loops in each cable loop group are laid according to a default phase ordering rule; and all cable loop groups are laid according to a preset laying rule, wherein M is integer multiples of N. According to the electromagnetic induction power transmission system provided by the invention, leakage flux and a calorific value of the overall system can be reduced and the energy utilization rate is improved.

The invention relates to the traffic control field, especially relates to a bidirectional green wave control method and a bidirectional green wave control device, which can be used to solve the problem of the conventional bidirectional green wave realizing scheme adopting the static green wave of inability of adapting well to the actual road traffic condition. The bidirectional green wave control method is characterized in that a target artery total green wave bandwidth acquisition rate can be determined according to the green signal ratio, the ideal green light starting time, and the phase difference of the intersection of various phase sequences of every intersection in the current adjusting period; whether the bidirectional green wave of the target artery can be determined; when the bidirectional green wave is realized, the traffic light of every intersection of the target artery can be set according to the green signal ratio, the phase sequence, and the phase difference of the intersection, which are corresponding to the total green wave bandwidth acquisition rate acquired during the realizing of the bidirectional green wave. By adopting the technical scheme provided by the invention, the parameter information of every intersection can be updated periodically, and therefore the traffic lights of the target artery can be set dynamically according to the parameter information corresponding to the total green wave bandwidth acquisition rate acquired during the realizing of the bidirectional green wave, and then the better adaptability to the actual road traffic condition can be provided.

The invention discloses a method and a system for optimal phase sequence determination of four-circuit transmission line on that same tower. The method comprises the following steps: a calculation model of a power frequency electric field of the four-circuit transmission line with the same tower is established; when the maximum electric field intensity is less than a first predetermined value, theheight of a conductor to ground is obtained; and the lowest height of the conductor is determined. The calculation model of audible noise is established. Based on the calculation model of the lowestheight of the conductor and the audible noise, the audible noise values at the evaluation points under all possible phase sequence arrangements are calculated by the exhaustive method. The calculationmodel calculates the distribution of the audible noise value, and eliminates the phase sequence arrangement mode of the asymmetric distribution of the audible noise value on both sides of the conductor center. A smaller noise value corresponding to a smaller one of the audible noise values is obtained according to a predetermined number in the selected phase sequence arrangement mode. A phase sequence arrangement of a region width having an electric field strength greater than a second predetermined value is calcuated. A phase sequence arrangement corresponding to the smallest noise value corresponding to the audible noise value and the smallest region width corresponding to the electric field strength greater than the second predetermined value is selected.

The invention discloses a phase sequence identification method for three-phase photovoltaic inverters, which includes the following steps of a, setting Usa, Usb and Usc as three phases of sampled voltage, initializing USa as the phase A, sampling voltage values of Usb and Usc when the raising edge of the Usa passes through the zero point, sampling once at each set time, and continuously sampling set times; b, adding one to the positive count value Pos_count with the initial value equal to zero if the sampled value of the Usb is smaller than zero and the sampled value of the Usc is larger than zero, and adding one to the negative count value Neg_count with the initial value equal to zero if the sampled value of the Usb is smaller than zero and the sampled value of the Usc is larger than zero during set times sampling; c, after set times sampling, setting the phase sequence of the Usa, the Usb and the Usc to be A, B and C correspondingly if the positive count value Pos_count is equal to the value of the set times, and setting the phase sequence of the Usa, the Usb and the Usc to be A,C and B correspondingly if the negative count value Neg_count is equal to the value of the set times.

The invention discloses a three-phase electro-magnetic double-salient-pole motor high-speed sensorless control strategy based on non-communicating phase terminal voltage coordinate transformation. The strategy includes: respectively detecting three-phase terminal voltage according to the feature that a three-phase electro-magnetic double-salient-pole motor has a zero crossing point in non-communicating reverse potential in an electric cycle, allowing the voltage to enter a digital controller to perform rotary coordinate transformation, consistent with the phase order of motor rotation, on the current upper tube communicating phase terminal voltage after the voltage is filtered by an RC filter, obtaining the rotary angle alpha ranging from 30 degrees to 60 degrees according to different rotation speeds, and judging the phase change points by detecting the zero crossing points of the current upper tube communicating phase terminal voltage after coordinate transformation. By the strategy, the defect that the reverse potential cannot be detected directly during high-speed operation is overcome, weight and size of the filter can be reduced, and the electro-magnetic features and mathematical models of the motor need not be known in advance. In addition, the strategy is applicable to three different chopping manners, and easy to implement.

The invention discloses a current phase sequence detection and phase locking device for a three-phase inverter and a phase locking and phase sequence identifying method. The device comprises a waveform amplitude limiting and shaping circuit which is used for waveform amplitude limiting and shaping of an input alternating current, a digital signal processor (DSP) control chip which is used for phase sequence detection and phase locking, and a level conversion circuit which is connected between the waveform amplitude limiting and shaping circuit and the DSP control chip. The method comprises the following steps of: determining the frequency of a power grid, and identifying phase sequence and phase locking. Based on the original inverter, the device and the method realize the automatic detection of phase sequence and phase locking by using the waveform amplitude limiting and shaping circuit and the level conversion circuit, and solve the problem of operation failure of the inverter caused by phase sequence error and output current waveform distortion of an inverter system caused by complete software phase lock.

The invention provides a method and a system for checking the phase sequence of a three-phase alternating current motor. The method comprises the steps that three-phase current corresponding to the motor controller of the three-phase alternating current motor is collected in real time; the quadrature axis voltage and the positive included angle are given, and the straight-axis voltage is adjusted;whether the phase sequences of the motor controller and the three-phase alternating current motor are consistent is determined through the three-phase current of the motor controller; and if the phase sequences are not the consistent, when the three-phase alternating current motor is in a current closed-loop mode, B-phase modulation waves and C-phase modulation waves are exchanged, and B-phase current and C-phase current are exchanged. According to the scheme, the quadrature axis voltage and the positive included angle are given; whether the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent through the magnitude and direction of the three-phase current of the motor controller; the directions are not consistent, B-phase modulation waves and C-phase modulation waves are exchanged, and B-phase current and C-phase current are exchanged to complete phase sequence correction of the three-phase alternating current motor; and the phase sequence directions of the three-phase alternating current motor and the motor controller are consistent, so as to ensure stable operation of the three-phase alternating current motor.

Provided is a three-phase type ring network cabinet secondary phase checking device, comprising a phase checking device housing, LED indicating lamps, a switch and contacts. The phase checking device housing is a square three-dimensional structure; the contacts comprise contact A1, contact B1, contact C1, contact A2, contact B2, and contact C2; the LED indicating lamps comprise lamp L1, lamp L2, lamp L3, lamp L4, lamp L5, and lamp L6; the LED indicating lamps are arranged on the front surface of the phase checking device housing in two rows and three columns; one side of the phase checking device housing is provided with the contact A1, contact B1, and contact C1, and the other side of the phase checking device housing is provided with the contact A2, contact B2, and contact C2; the phase checking device housing is internally provided with a phase checking device which is in connection with the contacts, the switch and the LED lamps. The invention also discloses a phase checking method utilizing the three-phase type ring network cabinet secondary phase checking device. The device and method can directly observe which phase breaks down, enhance phase checking accuracy, and greatly simplify operation.

A phase sequence included angle detection circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a diode D1, a diode D2, a diode D3, a photocoupler U1 and a photocoupler U2. The phase sequence included angle detection circuit has the advantages that fewer devices are used, the high anti-interference capacity is achieved, and reliability of a whole system is improved; a periphery device is composed of the resistors and the diodes, the complexity is low, and the machinability of the production is improved; the 5000 Vrms isolation characteristic is achieved, and the strong and weak electricity isolation can be achieved; the pure hardware sampling system is obtained, no software algorithm supports are needed, and the use difficulty is lowered; the phase sequence included angle detection circuit can serve as a power grid open phase judgment device; the phase sequence included angle detection circuit can directly tolerate the megohm meter insulation measurement in the insulation and voltage resistance testing experiment process.