296 results about "Half cycle" patented technology

The invention provides a control method of a power conversion circuit and an inverter. The power conversion circuit comprises a driver, a bootstrap unit, an upper switch tube and a lower switch tube. The method comprises the steps of obtaining a target duty ratio of on-off of an upper switching tube or a lower switching tube according to the maximum loss of a bootstrap diode and the voltage of the bootstrap diode; half cycles are obtained according to the target duty ratio and the voltage of the bootstrap capacitor, and the two half cycles form a work cycle; and controlling the driver to drive the upper switch tube to be switched on at the target duty ratio in the first half period of each work period and to be switched off at the second half period of each work period, and driving the lower switch tube to be switched off at the first half period of each work period and to be switched on at the target duty ratio in the second half period of each work period, so as to charge the bootstrap capacitor. Therefore, the problem that the bootstrap diode is damaged due to overlarge impact current can be reduced.

The invention relates to the technical field of power resource scheduling of an intelligent power grid, in particular to a power resource scheduling method and system based on a virtual power plant and a medium, and the method comprises the steps: collecting three-phase current data of a power generation end of the intelligent power grid and power data of each load end; determining the abnormal degree of the current data of the power generation end in the time period based on the difference distribution of adjacent half-cycle curves between different phase current data in the same time period and the dispersion degree of the phase current data in harmonic waves; the droop coefficient in the droop control algorithm is optimized and adjusted by combining the abrupt change characteristic and the trend significance degree of the total power data of all the load ends at the same moment in each time period; and using the optimized droop coefficient as a droop coefficient used when data acquired next time is used for power resource scheduling operation. The invention aims to realize reasonable scheduling of power resources and reduce deviation existing in power resource scheduling based on the virtual power plant.

The invention relates to the technical field of alternating current grid-connected operation countercurrent prevention, in particular to an alternating current countercurrent prevention method which has the advantages that the structure is simple, and countercurrent can be completely prevented; comprising alternating current positive and negative half-cycle phase sampling driving control, a power switch tube and an ideal diode or a universal diode. An alternating current input is connected to the alternating current positive and negative half-cycle phase sampling driving control part for sampling and is connected to the power switch tubes for providing power input, and the alternating current positive and negative half-cycle phase sampling driving control part outputs two paths of signals to respectively drive and control the corresponding power switch tubes. The output of the switching tube passes through the ideal diode or the universal diode and then outputs respective positive half-cycle and negative half-cycle alternating current in parallel.

A modulation signal processing apparatus and method is provided. The apparatus is applied to a microcontroller unit. The apparatus includes a first signal processing module and a second signal processing module. The first signal processing module is connected to an analog-to-digital converter of the microcontroller unit, and used for receiving a completion mark output by the converter, collecting a conversion value output by the converter, and generating corresponding bit data according to a total number of sampling times and a preset half-cycle value. The second signal processing module is connected to a PWM output timer of the microcontroller unit, and used for converting the bit data into a modulation data packet that complies with a Qi protocol, and respectively calculating a reload value of the PWM output timer and a corresponding frequency modulation parameter according to the modulation data packet and a preset modulation configuration parameter.

The invention relates to an electrical fault diagnosis method for a full-stage excitation system of a multi-stage starter generator, which comprises the following steps of: firstly, acquiring stator current of an exciter and calculating vector amplitude of the stator current, and then solving characteristic quantities such as an average value, a half-cycle average value, a ratio of a minimum derivative value to a maximum derivative value and the like of the vector amplitude of the stator current; the method is used for electrical fault diagnosis of the full-stage excitation system of the multi-stage starter generator. The method provided by the invention can diagnose whether the excitation system (comprising an exciter stator winding, an exciter rotor winding, a rotating rectifier and a main motor excitation winding) of the multi-stage starter generator has an electrical fault or not and the fault type on line at the static stage, the starting stage and the power generation stage of the system. The method has important significance for improving the operation reliability and the maintenance convenience of the multi-stage starting power generation system. The method provided by the invention can diagnose whether each component of the excitation system of the multistage starter generator has an electrical fault or not on line at the static stage, the starting stage and the power generation stage of the system, and judges the fault type.

A switching control system, including: switch units, configured to separately receive one of alternating currents and couple to a load; a detection unit, configured to detect the alternating currents; and a control unit, configured to, after receiving a switching signal, and in response to detecting that a power supply alternating current and a backup alternating current are in a polarity half cycle and a voltage difference is less than a preset voltage, perform: closing a first turn-on direction of a power supply switch unit; opening a second turn-on direction of a backup switch unit; closing a second turn-on direction of the power supply switch unit; and opening a first turn-on direction of the backup switch unit; where the first turn-on direction is opposite to a direction of the polarity half cycle, and the second turn-on direction is the same as the direction of the polarity half cycle.

The embodiment of the invention provides a control method and control circuit of a half-bridge flyback converter, a chip and power supply equipment. The control method comprises the steps that when the half-bridge flyback converter works in a free resonance state, in a first switching period, the second primary switching tube is controlled to be switched on so that the half-bridge flyback converter can exit from the free resonance state, after a preset switching-on duration, the second primary switching tube is controlled to be switched off so that excitation current can be negative current, and the half-bridge flyback converter can be switched off. And the half-bridge flyback converter enters the free resonance state again, and the first primary switch tube is controlled to be switched on at the moment which is separated from the switching-off moment of the second primary switch tube by odd number times of the free resonance half cycle, so that the valley bottom of the first primary switch tube is switched on, the efficiency of the half-bridge flyback converter can be improved, and the service life of the half-bridge flyback converter is prolonged. And the peak stress when the secondary switch tube is turned off can be reduced, so that the EMI of the half-bridge flyback converter is improved.

The invention provides a braking method and device of a linear motor, electronic equipment and a storage medium. The method comprises the steps that if the driving voltage of the linear motor after the current moment is smaller than the preset driving voltage, the braking voltage of the linear motor in the second integer number of half cycles is calculated based on the driving voltage before the current moment and the back electromotive force of the linear motor in the first integer number of half cycles after the current moment, the time length of the second integer number of half cycles is the same as that of the first integer number of half cycles; and whether the maximum value of the back electromotive force of the linear motor in the third integer half cycle is larger than or equal to the preset back electromotive force is judged, and whether the linear motor is braked or not is determined based on the judgment result. In this way, efficient and accurate braking of the linear motor can be achieved.

A power converter and a staircase modulation method therefor are provided. The power converter includes n cascaded bridges, where n≥2, the n cascaded bridges are each configured to output same multilevel pulses, the output n multilevel pulses are sequentially phase-shifted by a same angle, and the n multilevel pulses are superposed on each other to form a desired output pulse waveform of the power converter. Each of the n cascaded bridges is configured such that an output pulse of each cascaded bridge includes 2k+1 sub-pulses in each half cycle, where k≥1; and the 2k+1 sub-pulses are symmetrically distributed by using a (k+1)th sub-pulse as a center, pulse widths from a 1st sub-pulse to the (k+1)th sub-pulse sequentially increase, and pulse widths from the (k+1) sub-pulse to a (2k+1)th sub-pulse sequentially decrease.

The invention discloses a quantum phase-locked detection method based on entanglement enhancement, and the method comprises the steps: encoding quantum bits in a ground state and an excited state, and preparing the quantum bits into an initialized quantum state; loading a periodic multi-pulse sequence to act on the quantum bits; and loading a carrier pulse resonating with the ground state and the excited state, detecting the final quantum state of the quantum bit, and comparing curves of each component of the measurement density matrix and the theoretical density matrix changing along with the pulse time interval of the periodic multi-pulse sequence to obtain the half cycle and the amplitude of the sine wave to be measured. According to the method, measurement noise under the condition that the rotation angle and the detuning error exist can be effectively restrained, high measurement precision is kept under the condition that the rotation angle and the detuning error exist, and the robustness enables the method to be more reliable in practical application.

The invention provides a reluctance motor sensorless control method and system based on high-frequency voltage correction, and the method comprises the steps: carrying out the sampling of three-phase current outputted by a synchronous reluctance motor, and obtaining three-phase current data; converting the three-phase current to obtain alpha-beta-axis current; processing the alpha-beta axis current and the lagged half-cycle signal thereof to obtain high-frequency alpha-beta axis current; converting the alpha-beta-axis current to obtain a dq-axis current, and processing the dq-axis current and a signal of lagging half cycle of the dq-axis current to obtain a fundamental frequency dq-axis current; subtracting the lagging current from the high-frequency alpha-beta-axis current to obtain a current variable quantity; processing the obtained current variable quantity through a phase-locked loop structure to obtain an estimated rotating speed and an estimated rotor position; and processing the estimated rotating speed and the estimated rotor position to obtain a switching signal, wherein the switching signal is used for controlling the synchronous reluctance motor.

A thermal impedance monitoring process for a power module of a power converter for converting a DC current to an AC current, or converting an AC circuit to a DC current, where a semiconductor dissipates asymmetric losses between two half cycles of an AC frequency f of the AC current, said power module comprising at least a semiconductor die, a semiconductor die is attached to a stack of materials of layers for heat dissipation and / or electrical connection thereof, the process comprising: sampling and measuring a signal related to a junction temperature Tj of the semiconductor die at a frequency higher than twice the AC frequency of the AC current, calculating a duration [Delta] t = tTjmax-tTjmin between a moment tTjmax at which the junction temperature of the semiconductor die is at a maximum value and a moment tTjmin at which the junction temperature is at a minimum value in one cycle of the AC current, and storing the duration [Delta] t in a memory, repeating the step of sampling and measuring said signal and the step of calculating said duration at different times tx = t0 to tm during the operating life of the power module to provide a series of durations [Delta] t0 to [Delta] tm, and comparing the values of said durations [Delta] t0 to [Delta] tm for monitoring the evolution of said duration [Delta] t, and determining the evolution of the degradation of the thermal impedance of the power module.

The invention discloses a single-phase differential Boost inverter voltage zero-crossing compensation method based on a DSP (Digital Signal Processor). According to the method provided by the invention, the single-phase differential Boost inverter works under a discontinuous modulation strategy, and two Boost circuit modules alternately output positive and negative half cycles of alternating current sinusoidal voltage, so that the differential total output is the required alternating current sinusoidal voltage; wherein in the last switching period before the positive-negative half-cycle switching, the bridge arm switch actively turns off the interrupted current so as to eliminate zero crossing point oscillation caused by the residual energy of the inductor after the positive-negative half-cycle zero crossing point; in a first switching period after negative-positive half cycle switching, an initial pulse is widened for eliminating zero crossing point oscillation caused by inductive current mutation after negative-positive half cycle zero crossing.

The invention relates to the technical field of power conversion, and particularly discloses a modulation method and system of a converter, equipment and a medium. The converter comprises at least two H bridges and a multi-winding high-frequency isolation transformer. The modulation method of the converter comprises the following steps: setting modulation parameters; on the basis of the modulation parameter, modulating the converter by using a preset modulation strategy; wherein the set modulation parameters are as follows: different duty ratios and different out-shift ratios are respectively set for the first half cycle and the second half cycle of each switching cycle during modulation of the converter, and phase-shift zero-voltage sequences with different duration proportions are respectively added when the first half cycle and the second half cycle of each switching cycle are ended; therefore, the equivalent switching frequencies of the first half period and the second half period of each switching period are reduced by different proportions. By adopting the method and the device, when modulation input parameters change, the delay of power transmission is small, the precision is high, and in addition, the method and the device are simple and easy to implement, strong in robustness, strong in practicability and high in light load efficiency.

A controller for a resonant converter. The controller is configured to: compare a measured current signal with a positive current threshold; compare the measured current signal with a negative current threshold; and set a power reduction mode as active if either or both: the measured current signal is less than the positive current threshold at the end of the preceding high-side switch half cycle; and the measured current signal is greater than the negative current threshold at the end of the preceding low-side switch half cycle. While the power reduction mode is active: the controller gradually decreases the value of a reduced power signal. While the power reduction mode is inactive: the controller gradually increases the value of the reduced power signal. the controller sets an upper voltage threshold value and a lower voltage threshold value based on the lower of: i) the reduced power signal; and ii) a power setting signal.

System and method for controlling one or more light emitting diodes. For example, the system includes: a phase detector configured to process information associated with a rectified voltage generated by a rectifier and related to a TRIAC dimmer, the rectified voltage corresponding to a first waveform during a first half cycle of an AC voltage and corresponding to a second waveform during a second half cycle of the AC voltage, the phase detector being further configured to generate a phase detection signal representing a first time duration during which the first waveform indicates that the rectified voltage is larger than a predetermined threshold and representing a second time duration during which the second waveform indicates that the rectified voltage is larger than the predetermined threshold; and a mode detector configured to process information associated with the rectified voltage.

The embodiment of the invention discloses a current sampling calibration method, electronic equipment and a storage medium. The method comprises the steps of obtaining circulating voltage output by a voltage loop, and judging whether a fluctuation value of the circulating voltage is smaller than a preset fluctuation threshold value or not; when the fluctuation value is smaller than a preset fluctuation threshold value, current loop output values in a preset number of power frequency periods are collected and subjected to filtering processing, and filtering values corresponding to the positive and negative half cycles of the input end are obtained; calculating a difference absolute value of the two filtering values, and judging whether the difference absolute value is greater than a preset calibration threshold; when the absolute value of the difference value is greater than a preset calibration threshold value, selecting one as a reference filtering value, and determining a correction coefficient according to the size relation of the two filtering values; and taking the reference filtering value and the adjustment filtering value processed by the correction coefficient as filtering values of corresponding half cycles according to the level of the polarity signal. By means of the mode, sampling gain deviation of the mutual inductor can be eliminated through self-correction, and performance indexes such as total harmonic distortion and power factors can be improved.

Systems and methods are disclosed for reduced-power serial data links. A clock-forwarded serial link carries a clock lane and one or more data lanes. Every active serial data cycle is accompanied by its own serial clock edge: a clock delay allows the same clock edge to drive data at a transmitter and latch data at a receiver. Power is saved by idling the serial clock when data is not being transmitted. A valid signal can be omitted, providing a space saving. At the destination, similar clock-forwarding and delay enables a single parallel clock edge to drive data to the boundary of its clock domain, e.g. from a deserializer to a FIFO. The data link exhibits zero-cycle entry and exit. Variations with half- or single-cycle entry or exit are disclosed.

The invention discloses a self-powered synchronous rectification active bridge, a control method thereof and a power supply system. An active bridge belongs to the technical field of power electronics and comprises a full-bridge rectifying circuit composed of four switching devices, a self-powered circuit taking electricity from an alternating current input end and a control circuit. And the control circuit detects an alternating current input phase, generates a driving signal with dead time, and controls the switching device to be alternately conducted in positive and negative half cycles to realize synchronous rectification. The self-powered circuit is preferably a charge pump, and an external auxiliary power supply is not needed. Through integration of synchronous rectification, self-power supply and intelligent control, the rectification efficiency and the power density are remarkably improved, a traditional rectifier bridge is conveniently and directly replaced through the modular design, and the high-power rectifier bridge can be widely applied to high-power scenes.

A control method and a control circuit for a bidirectional resonant direct-current converter are provided. The control method includes determining a zero-crossing point of a secondary resonant current of the bidirectional resonant direct-current converter, determining, for a switching transistor to be turned off in the secondary circuit within each half cycle of the secondary resonant current, a turn-off start time instant of the switching transistor as an end time instant of a preset delay duration starting from the zero-crossing point; and determining, for a switching transistor to be turned on in the secondary circuit within each half cycle of the secondary resonant current, a turn-on start time instant of the switching transistor as an end time instant of a dead time starting from the turn-off start time instant of the switching transistor complementary to the switching transistor to be turned on.

The application discloses a self-interference cancellation device in a full duplex system, which is an independently deployable hardware module connected between a radio frequency transceiver and an antenna, and comprises a switch matrix and a phase shift network unit, a control signal unit, an interface unit and a power supply unit. The switch matrix and the phase shift network unit comprise a radio frequency switch matrix and an inverter composed of a balun transformer; the control signal unit comprises a microcontroller. The microcontroller is configured to output a periodic control signal to synchronously control the radio frequency switch matrix to alternately switch the connection between the two antennas and the transmitting and receiving ports in the first half cycle and the second half cycle in a control period, and synchronously control the phase shift network to introduce a 180-degree fixed phase shift in the second half cycle. Through the above operation, the self-interference signal spectrum is moved away from the baseband, and then low-pass filtering is performed on the latter stage to realize endogenous elimination. The application does not need channel estimation, has simple hardware architecture, low cost and good compatibility, and is convenient for full duplex upgrading of existing equipment.

The application discloses a kind of permanent magnet synchronous motor position sensorless control demodulation methods based on three-branch external tangent demodulation, belong to permanent magnet synchronous motor control field.This method injects random half-cycle square wave high-frequency voltage signal in the estimation synchronous rotating coordinate system, collects three-phase current and extracts high-frequency current component under stationary αβ coordinate system;According to the estimated electrical angle, construct three sets of three-branch external combined current variables, obtain the demodulation quantity corresponding to the position error sine and cosine components by algebraic combination, then obtain the position error signal by external tangent relationship, and estimate rotor position and speed by phase-locked loop.This method does not depend on the strict synchronization multiplication of random square wave demodulation carrier and sampled current, can weaken or avoid the equivalent delay influence of about 1.5Ts caused by digital sampling, improve the position estimation accuracy and robustness under random half-cycle switching condition.

The present invention provides a modular multi-level converter EAR‑MMC with energy alternate reset, which is composed of at least two-phase circuits, and the phase bridge arm of each phase circuit is composed of two sub-module strings and two parallel semiconductor switch strings connecting the sub-module strings, wherein: the outer ends of the two sub-module strings are respectively connected to the positive and negative ends of the DC bus; the midpoint of the first semiconductor switch string is connected to the AC end; the midpoint of the second semiconductor switch string is connected to the midpoint of the second semiconductor switch string of the other phase bridge arm through an AC inductor. The phase bridge arm of each phase circuit of the EAR‑MMC switches the switch devices on both sides of the semiconductor switch string of the phase bridge arm, and controls when the phase bridge arm outputs an AC voltage, the two sub-module strings of the phase bridge arm alternately perform AC end voltage shaping and energy reset in the positive and negative half cycles of the AC voltage. Under the same conditions, the number of sub-modules and the number of fully controlled devices required by the EAR‑MMC are only 50% of those of the MMC, which is conducive to the miniaturization and lightweight design of systems such as flexible direct current transmission (VSC‑HVDC).

The invention relates to the technical field of capacitance detection circuits, in particular to a capacitance digital conversion circuit based on phase-sensitive integration. The circuit comprises a phase shift circuit unit, a capacitance detection unit, a phase control unit and a digital processing unit. According to the invention, an excitation signal is converted into an excitation signal which is 90 degrees ahead by using a phase shift circuit through a phase shift circuit unit, a capacitance detection unit controls a single-pole double-throw switch S1 to alternately access the excitation signal and an inversion signal to a to-be-detected capacitor Cx and a reference capacitor C0, and a phase control unit utilizes integration-deintegration double stages in an integration stage. Phase signals are converted into high and low levels through a comparator so as to control overturning of a capacitor CF pole plate, the digital processing unit carries out phase sampling counting at 0 degree and 180 degrees, the capacitance value is calculated according to the ratio of the number of integration cycles to the number of deintegration half cycles, the influence of stray capacitance is reduced, and the measurement precision is improved.

Disclosed herein is a single-input multi-output resonant regulating rectifier. The single-input multi-output resonant regulating rectifier may include: a conversion circuit unit converting a wireless power alternating current (AC) signal into half-cycle input signals VINN and VINP; and an output generation circuit unit generating a plurality of outputs within a half cycle by generating a plurality of gate signals in a plurality of different regions within each half cycle based on the half-cycle input signal VINN input through the conversion circuit unit.

The application provides an extended dual-port RAM communication device based on a PCIE bus and an implementation method, which communicates with a CPU through a PCIE bus, connects with external equipment through an interface, and realizes dual-port RAM communication between the PCIE bus CPU and the external equipment. The application can work independently or in parallel in a far-end mode and a near-end mode. The extended dual-port RAM communication device based on the PCIE bus supports physical connection with a dual-port RAM communication port of the external equipment through a plurality of optional types of interfaces, and matches the electrical characteristics of the dual-port RAM communication physical port of different external equipment. The extended dual-port RAM communication device based on the PCIE bus generates a square wave signal and transmits the square wave signal to the CPU and the external equipment at both ends of the dual-port RAM communication, so that the CPU and the external equipment respectively perform read and write access to the dual-port RAM in the positive half cycle and the negative half cycle of the square wave signal, and the conflict caused by simultaneous read and write of both parties to the same address unit in the dual-port RAM is avoided.

This invention relates to the field of motherboard programming, and in particular to a motherboard programming control method, device, and system. The method includes, during the programming process, controlling the level changes of the cache state machine and the block addressing state machine to determine whether the two state machines will simultaneously be in a metastable state during state updates. If so, a micropulse is generated and inserted into the oscillation half-cycle, so that the time when the two state machines are simultaneously in a metastable state is staggered from the clock edge before data is written. This avoids data rejection due to the continuous metastable state of the two state machines, effectively ensuring the integrity of data writing and thus guaranteeing the quality of motherboard programming.

The subject-matter of the present disclosure provides a transmitter for a master clock of an audio system. The transmitter comprises an input configured to receive a message to be sent to a receiver of an audio device of the audio system and clock frequency information of a clock signal for synchronising the audio device; a data stream generator configured to determine a data stream based on the message; a pulse shaper configured to generate an encoded clock signal in the form of a rectangular wave having an initiating edge timing based on the clock frequency and a terminating edge timing being earlier than or later than a half cycle of the encoded clock signal depending on a bit value of the data stream; and an output configured to transmit the encoded clock signal to the receiver.

A switching control system, including: switch units, configured to separately receive one of alternating currents and couple to a load; a detection unit, configured to detect the alternating currents; and a control unit, configured to, after receiving a switching signal, and in response to detecting that a power supply alternating current and a backup alternating current are in a polarity half cycle and a voltage difference is less than a preset voltage, perform: closing a first turn-on direction of a power supply switch unit; opening a second turn-on direction of a backup switch unit; closing a second turn-on direction of the power supply switch unit; and opening a first turn-on direction of the backup switch unit; where the first turn-on direction is opposite to a direction of the polarity half cycle, and the second turn-on direction is the same as the direction of the polarity half cycle.

The invention provides a control method and device of a motor system, a medium, a controller and electric equipment.The control method of the motor system comprises the steps that a first voltage signal and a second voltage signal on an alternating current bus are obtained, the first voltage signal is the positive half cycle of an alternating current voltage signal on the alternating current bus, and the second voltage signal is the negative half cycle of the alternating current voltage signal on the alternating current bus; the second voltage signal is a negative half cycle of the AC voltage signal; determining an AC voltage signal based on the first voltage signal and the second voltage signal; inputting the AC voltage signal to a phase-locked loop to obtain a voltage phase corresponding to the AC voltage signal; correcting the current instruction based on the voltage phase to obtain a corrected current instruction; and controlling the motor system based on the corrected current instruction. In the process of determining the voltage phase, an operational amplifier and a differential circuit do not need to be used, so that the control cost of the motor system can be reduced.