380 results about "Hysteresis control" patented technology

In a multi-phase power converter using a phase-locked loop (PLL) arrangement for interleaving of pulse frequency modulated (PFM) pulses of the respective phases, improved transient response, improved stability of high bandwidth output voltage feedback loop, guaranteed stability of the PLL loop and avoidance of jittering and phase cancellation issues are achieved by anchoring the bandwidth at the frequency of peak phase margin. This methodology is applicable to multi-phase power conveners of any number of phases and any known or foreseeable topology for individual phases and is not only applicable to power converters operating under constant on-time control, but is extendable to ramp pulse modulation (RPM) control and hysteresis control. Interleaving of pulses from all phases is simplified through use of phase managers with a reduced number of PLLS using hybrid interleaving arrangements that do not exhibit jittering even when ripple is completely canceled.

A sigma delta modulator includes a modulator module that includes a quantizer with variable hysteresis, which receives an input signal to perform necessary modulation operations. A non-linear mapping module receives a signal associated with said input signal and tabulates the necessary hysteresis control information so as to reduce the transition rate of the modulator module.

The invention discloses a full-vector control method of a five-phase fault-tolerant permanent magnet motor. According to the method, a five-phase SVPWM method is adopted when the motor operates normally; after a one-phase open-circuit fault occurs on the motor, the traditional SVPWM method and a current hysteresis control method are combined together to re-construct a post-fault coordinate system; re-distribution and sector reconstruction of space vectors are performed on the reconstructed coordinate system; target vectors are synthetized through re-selection of the space vectors; and therefore, full-vector control on the five-phase fault-tolerant permanent magnet motor can be realized. With the full-vector control method adopted, problems such as hardware variation and loop width selection brought about by the switching of normal five-phase SVPWM to current hysteresis control existing on most current methods can be solved, and tracking performance can be ensured, and torque ripples after open-circuit faults can be effectively restrained.

The invention relates to a grid connected inverter control method based on hysteresis modulation under the unbalanced grid voltage condition. The control method comprises that the voltage of a dc bus is detected, and a reference active power value is calculated via a PI (Proportion Integration) regulator; the positive sequence components and the negative sequence components of the grid voltage under a two-phase rotating coordinate system are obtained by processing three phases of detected grid voltages via coordinate conversion and positive/negative sequence component decomposition; three phases of instantaneous reference-current values are obtained from the reference active power value and the positive and negative sequence components of the grid voltage via calculation, coordinate conversion and the like; and finally, the three phases of instantaneous reference-current values are compared with three phases of practical current values, a certain hysteresis width is set, and driving pulses are emitted in a hysteresis control principle. The control method requires no parameters of grid connected filtering reactors, and only includes the PI regulator, thereby providing convenience for construction realization; and under the unbalanced grid voltage condition, the stability of instantaneous grid power can be effectively ensured, the voltage fluctuation of the dc bus can be lowered, and the stability of the grid connected inverters is improved.

The invention discloses an active power filter device based on a coupled inductance, which is composed of a signal acquisition module, a main control module, a drive module, a power conversion module and an LCL filter module based on a coupled inductance. The steps of extracting command current are as follows: first, extract sinωt and cosωt which are synchronized with grid A-phase voltage ua through digital phase-locked loop; secondly, transform the three-phase grid current into dqo coordinates to obtain current id, iq in dqo coordinate system , io; the third is to perform digital low-pass filtering on id and iq to extract their DC components; the fourth is to inversely transform io, sinωt and cosωt to dqo coordinates; the fifth is to perform subtraction to obtain the three-phase grid current The fundamental reactive and harmonic currents in . After hysteresis comparison control, PWM gating signals and trigger pulses are generated to control the orderly on-off of each IGBT in the power conversion module to generate PWM voltage, which is filtered by the filter module and then injected into the grid for compensation.

The present invention relates to a direct-torque brushless DC servo-control system and the working method thereof. The controller includes a coordinate transformation unit, a magnetic linkage computing unit, a torque computing unit, a magnetic linkage and a torque hysteresis control unit, a switch watch and an inverter unit; in the direct-torque brushless DC servo-control system in the present invention, the magnetic linkage and torque hysteresis control unit are used for comparing the stator magnetic linkage Psi s from the magnetic linkage computing unit and the stator torque Te from the torque computing unit respectively with the reference value Psi s * and T*e, and for outputting the magnetic linkage adjusting signal Tau and torque adjusting signal Phi having the corresponding frequency of 4-8kHz according to the compared result to improve the switch frequency of the inverter and reduce the torque pulsation. The system in the present invention has a good control effect to the torque and a quick response, and the problem of the torque pulsation of the brushless DC electric motor is solved.

The invention discloses a vehicle-mounted composite power supply system of an electric vehicle and a control method. Through a voltage and current acquisition circuit, a voltage value and a current value of a motor inverter end, and voltage values of a battery set and a supercapacitor are obtained, and the processed to obtain required power, battery set SOC and supercapacitor SOC, which are used as decision-making input variables of a fuzzy logic control module. According to actual operation working conditions of the electric vehicle, a proper logic threshold value control strategy is formulated and by use of fuzzy control, fuzzification is performed on fixed rule parameters in a logic threshold, so rules are further refined, control thinking is further precise and results are further optimized. Compared with real-time power, the peak value of actual average power and the switching frequency are greatly reduced. By combining the power hysteresis control, the switching frequency of working modes of the system and the output frequency of the battery set are further improved, energy loss, caused by mode switching, of a vehicle-mounted double-energy system is reduced, service lifetime of the battery set is prolonged and efficiency and stability of the system are improved.

The invention discloses a driving control system and a control method thereof based on a dual-power supply open-type winding permanent magnet synchronous motor. An open-type winding permanent magnet synchronous motor structure with dual power supplies and dual inverters for power supply is adopted, an electronic switch group is added, a delta winding connection is realized, the structure can be used for a dual-power supply structure of different power types, and voltage of two power supplies can be allowed to be different and change in real time. through torque saturation determination and rotation speed threshold control, automatic switching is realized among a star winding mode, a delta winding mode and a dual-inverter common control mode, and switching loss is reduced. A dual-inverter current hysteresis control algorithm in a low switching frequency mode and a large power differential mode is provided for the dual-inverter common control mode, and effects of realizing multi-level control and providing different dual-power supply energy allocation can be realized.

The invention discloses a series-parallel connection output tri-level half-bridge inverter and a half period hysteresis control method thereof. The inverter comprises a power supply, a first tri-level half-bridge inverter, a second tri-level half-bridge inverter, an output filter circuit and a load. Each of the tri-level half-bridge inverters comprised in the method works separately; when in the half period with positive output inductive current, an upper bridge leg of each tri-level half-bridge inverter works; when in the half period with negative output inductive current, a lower bridge leg of each tri-level half-bridge inverter works. Under the mode of half period current hysteresis control, the inverter does not have circulating current and reduces the conducting times of a body diode, thus reducing the loss caused by reverse restoration of the diode, improving the efficiencies of the circuit and the switch and further reducing the volume and weight of a filter. Meanwhile, when in the whole working process, the circuit can work without dead area.

The invention provides a control method and a control device for a permanent magnet vacuum circuit breaker. The control method comprises the following steps: measuring coil current of a permanent magnet mechanism; and acquiring a reference current curve for controlling in real time, as well as a hysteresis control algorithm unit. The control method is characterized in that any part is not required to be additionally arranged on a circuit breaker body; the current of a coil is measured in real time and is compared with reference current and an actual trigger signal of a power device is determined by a hysteresis control algorithm, so that the real-time closed loop control over the coil current is realized and further the switch-on-off time of the permanent magnet vacuum circuit breaker is kept consistent; and the realization of corresponding device is designed according to the method. Proved by actual experiments, the control method has the characteristics that the dispersibility of the switch-on-off time of the vacuum circuit breaker is effectively reduced and the dynamic error range of the switch-on-off of the vacuum circuit breaker is maintained at +/-0.3ms.

The invention provides a charger detection device for a battery protection cascade system. The charger detection device comprises N battery protection chips which are in one-to-one correspondence connection with N battery strings, wherein the first battery protection chip is a master chip and the rest battery protection chips are cascade chips; the N battery strings are connected in series, and respectively comprise M batteries, and N and M are natural numbers more than or equal to 2; each battery protection chip comprises a grounding end, a power end, a master and slave chip select signal end and a charger detection port; a connecting point of the power end of the Nth battery protection chip and the positive terminal of the Nth battery string is extracted to form the positive end of a battery pack, a connecting point of the grounding end of the master chip and the negative terminal of the first battery string is extracted to form the negative end of the battery pack, and a charger is connected between the positive end and the negative end; and the charger detection port of the master chip is connected to the negative end of the battery pack through a port resistor, the voltage of the battery pack is detected, and the connecting state of the charger is judged. The charger detection device can safely and reliably detect the connecting state of the charger, transmit an overvoltage hysteresis control signal to the cascade chips, and improve the safety of an application system.

The invention discloses a direct torque control method for a brushless direct current motor. By speed and torque double closed loop control, a rotating speed loop is used as an outer loop, and a torque loop is used as an inner loop; motor speed is calculated according to an output signal of a Hall sensor of the brushless direct current motor, and the motor speed is compared with reference speed to obtain speed error; an output value obtained after fuzzy self-adaptation adjustment is used as a torque expectation value; torque error is obtained by subtracting actual torque from expectation torque, wherein the actual torque is calculated by multiplying back-EMF (Electromotive Force) and phase current; the torque error is inputted into a hysteresis comparator; the hysteresis comparator outputs a position signal of a rotor; and an appropriate voltage vector is selected from a formulated switch list to control an inverter bridge connected with a DC power supply so as to make the brushless direct current motor output stable torque. By the method, the defect that current hysteresis control has a poor effect of inhibiting electromagnetic torque is avoided, and the problem that a traditional PID control method has low precision and poor anti-jamming capability in control of BLDCM is overcome.

The invention relates to a five-phase asynchronous motor control strategy based on stator magnetic field orientation. Considering the characteristics of a five-phase asynchronous motor, the control strategy combines the advantages of vector control and direct torque control. Starting from the torque control effect, on the basis of voltage drop compensation of the stator resistance, the stator fluxlinkage is controlled by the stator straight axis potential. The purpose of controlling the torque is achieved by controlling the current torque component. The continuous control of the torque and the stator flux linkage is realized. The dependence of the system controller on the rotor parameters is avoided. A continuous control method is adopted to overcome torque ripple caused by hysteresis control. The control strategy provided by the invention is suitable for the fields of power electronics and power transmission.

The invention discloses a current hysteresis control method of a three-phase four-switch-type active filter. The hysteresis control method of the three-phase four-switch-type active filter comprises the following steps: 1, firstly, three-phase reference directive current of an active filter and three-phase compensation current output actually are converted into a coordinate system with alpha-beta two-phase orthogonality by Park conversion; 2, output signals d alpha and d beta are obtained from error signals between the reference current and the actual output current after Park conversion by a hysteresis comparator; 3, a corresponding switch state table is obtained according to the topological structure of the three-phase four-switch-type active filter, and the switch action functions of two bridge arms are obtained by combining with the hysteresis comparison result and the switch state result, so that the hysteresis control of the three-phase four-switch-type active filter is realized. The hysteresis control method of the three-phase four-switch-type active filter, which is provided by the invention, is simple and reliable, is good in dynamic performance, and has favorable economic significance and market prospect.

The invention relates to an initial alignment detecting method of rotor position in permanent magnet synchronous motor. The detecting method includes steps of inferring an angle range of the spatial position of a motor rotor through pulse signal U, V, W and obtaining an initial angle, starting a servo motor to perform a closed-loop vector control and lock the rotor position, performing current hysteresis control processing and detecting phase current changing rate of the motor, and obtaining an accurate rotor angle value according to the relationship of the phase current changing rate and rotor angles. According to the detecting method, the reliability of the test is improved by detecting the current changing rate, and the closed-loop control is introduced before testing the current to guarantee that the position of the motor rotor will not change. The detecting method is especially applicable to motor with a larger cogging torque and occasions demanding higher initial positions, thereby the motor is guaranteed to start at most torque, starting performance of the motor is improved, the detecting process is easy and convenient, working performance is stable, and applicable range is wider.

The invention provides a facility agriculture greenhouse environment parameter self-adaptation controlling method. The facility agriculture greenhouse environment parameter self-adaptation controlling method includes the following steps of achieving self-adaptation control over greenhouse environment information parameters and auxiliary facilities by the adoption of a method of combining fuzzy control, a PID control and manual control and achieving automatic conversion of control modes based on greenhouse environment information at the same time based on a greenhouse environment self-adaptation data base, by the adoption of multilevel schema conversion control, and on the basis of set value control; gradually optimizing and perfecting the greenhouse environment self-adaptation data base according to greenhouse environment real-time information, invoking information in the data base by means of a priority level automatic identification function, and finishing self-tuning of set values; and setting intermediate values by the adoption of hysteresis control method and on the basis of the set value control in order to conduct optimizing adjustment. The facility agriculture greenhouse environment parameter self-adaptation controlling method achieves the self-adaptation control of the greenhouse environment parameters, reduces motion frequency of equipment, prolongs the service life of the equipment, improves a greenhouse management mode, improves labor productivity, and has strong practical value.

The invention relates to a direct-current bus photoelectric real-time confluence system and a control method, and belongs to the field of distributed photovoltaic direct-current micro-grid power sources. The direct-current bus photoelectric real-time confluence system comprises a direct-current input source which is connected with a one-way rectification controller, and the output end of the one-way rectification controller is connected with a bus capacitor bank. The input end of the bus capacitor bank is connected with a DC/DC converter which is used for achieving adjustment of output power of a photovoltaic cell panel. Two ends of the bus capacitor bank are connected with a discharging circuit in parallel, and meanwhile the output end of the bus capacitor bank is connected with a direct-current load. By means of multilevel hysteresis control of the voltage of the bus capacitor bank, the working mode of the system is confirmed, therefore, direct-current stabilized-voltage output is achieved, and normal power supply of the load is guaranteed. On the premise that stabilization of the output voltage is guaranteed, the photovoltaic cell panel is used as auxiliary energy, real-time confluence of photovoltaic energy and the direct-current input source is achieved, the energy utilization rate is improved, power generation cost is lowered, environmental pollution is reduced, and good universality and practical value are obtained.

The invention discloses a V2G control strategy for cluster electric vehicles. The V2G control strategy comprises that an equipment level hysteresis control model for a single electric vehicle is established; a status priority aggregative indicator of the cluster electric vehicles is put forward; and the V2G control strategy for the cluster electric vehicles considering the priority status of the electric vehicles is put forward. According to the V2G control strategy for the cluster electric vehicles, by controlling charging, discharging and closing states of the electric vehicles, load regulation of the cluster electric vehicles is achieved, participation in power system demand response is realized, and the target that the cluster electric vehicles can accurately and quickly track the power within the controllable capacity range and given by a power system dispatching mechanism is realized.

A sleep circuit for use in a resonant inverter is disclosed. The sleep circuit activates a “sleep mode” (non-continuous operation) when the inverter output has no connected load, or a connected load is non-operative (e.g., fails). The “sleep mode” utilizes hysteresis control via the under voltage lockout protection feature of a control IC of the inverter. A primary DC source permanently connects to the Vcc pin of the control IC for startup (on) and burst (non-continuous) operation modes. An auxiliary DC source connects to the Vcc pin via a switch for continuous operation mode. A load current sensor controls the switch. When a sensed output current is above a threshold level, the switch connects the auxiliary DC source, and the control IC (and the inverter) operates continuously. When the sensed output current falls below the threshold, the auxiliary DC source is not provided and the inverter operates in “sleep mode”.

An apparatus for providing programmable hysteresis control using an enable pin of a device is disclosed. An enable pin is configured to receive an input signal to enable and disable an associated device responsive to the input signal. A current sink is attached to the enable pin and is responsive to circuitry that disables the current sink responsive to application of the input signal at a first voltage level and enables the current sink responsive to application of the input signal at a second voltage level.

A voltage monitor circuit for biasing a well region of a CMOS circuit includes a self-biased comparator which compares first (INP) and second (INN) input signals. The comparator includes first (MN1) and second (MN2) N-channel transistors with grounded sources, a drain of the first N-channel transistor and a gate of the second N-channel transistor being coupled to a first output (OUTN), and a drain of the second N-channel transistor and a gate of the first N-channel transistor being coupled to a second output (OUTP). First (MP1) and second (MP2) P-channel transistors are operated to couple the second or first input signal to the second or first output, respectively, by controlling the gate-to-source voltage of the first or second P-channel transistor according to the polarity of a voltage difference between the first and second input signals.

The invention provides a control method for a low-voltage static var generator based on a voltage space vector, and belongs to the control methods for the low-voltage static var generators. The method comprises the steps that an actual output current and command current of a STATCOM are detected according to a STATCOM detection unit, an error current vector delta is determined, and a STATCOM mathematical model is combined to determine a constraint condition of an equivalent error voltage; the STATCOM adopts a double hysteresis control method, the width of an inner loop of a hysteresis loop is I<w1>, the width of outer outer loop of the hysteresis loop is I<w0>, when ||delta|| is grater than I<w0>, the error current vector delta is determined to be at the outer loop, and the current inner loop adopts an internal model controller to accurately calculate an output voltage u<c>* of the STATCOM; when the ||delta|| is greater than I<w1> and less than I<w0>, the error current vector delta is determined to be at the inner loop, a system is in a stable state, and a voltage vector method is adopted to control the STATCOM to output a fundamental voltage vector in a sampling period; when the ||delta|| is less than I<w1>, the error current is located in a dead zone, the on-off state remains unchanged, and the stability of the system is improved. A voltage space vector modulation method and the hysteresis control method are combined, the compensation precision is high, the response speed is fast, the switching frequency is low, and the performance requirements of the STATCOM are met.

The invention discloses a control method of a five-phase inverter dual three-phase motor system, and belongs to the technical field of motor control. The control method omprises the following steps: firstly, using a three-phase current hysteresis control method to get theoretical on-off states of three-phase windings of two two-phase motors; then, selecting the theoretical on/off state of a phase winding with greater absolute value of current deviation from two-phase windings connected with a public bridge arm as an actual on/off state of the public bridge arm, wherein the actual on-off state of an independent bridge arm is equivalent to the theoretical on/off state of the phase winding connected with the independent bridge arm; finally, controlling a five-phase inverter through the obtained actual on-off state. The invention further discloses a five-phase inverter dual three-phase motor system using the control method above. Compared with the prior art, the control method has the advantages of simple system structure, strong robustness and wider application scope.