98results about How to "Small current fluctuation" patented technology

The invention relates to a motor rotor position detection method, and specifically relates to position detection of a rotor of a permanent magnet synchronous motor. The method comprises the steps of installing three Hall elements at positions spacing from each other by 120-degree electrical angle of a stator side of the permanent magnet synchronous motor so as to acquire Hall signals, after Hall detection signals are obtained, on the one hand, determining which area the rotor is in according to a correspondence relationship of the Hall signal and the rotor angle, on the other hand, calculatinga rotor rotating speed through a T method; estimating the rotor angle according to the obtained area in which the rotor is and the rotor rotating speed; and correcting the rotor angle by using an angle slow correction method so as to determine the position of the rotor. In the method, the Hall elements are used to detect the position of the rotor, so that the method has the advantages of being low-cost, easy and convenient; a clock division value of a timer is corrected in real time, so that the optimal resolution is guaranteed; and the rotor angle is corrected by using the angle slow correction method, so that current fluctuation is reduced effectively, and the motor runs stably.

The invention discloses a reciprocating rack linear driving oil pumping unit, which comprises a rack, a walking beam, driving and transmission parts, a unit body part, an air balanced part, an energy storage part and a control part, wherein the rotation of a motor controlled by a controller around a vertical shaft is changed into the rotation of gears around a horizontal shaft by direction changing of a gear transmission box; the gears drive racks in the unit body of the oil pumping unit to perform up-and-down reciprocating linear motion so as to drive a polish rod for oil pumping; and the controller analyzes the operating situation of the oil pumping unit according to a data signal which is measured by a sensor, automatically optimizes and adjusts the stroke and stroke frequency of the oil pumping unit, and can transmit the signal to a production management department for manual remote monitoring control. By adoption of technologies of reciprocating induction motor driving, rack linear driving, real-time monitoring and adjustment, air balance and capacitor energy storage, the reciprocating rack linear driving oil pumping unit is smooth in operation, low in current fluctuation and low in reactive electric quantity loss of the motor, has the advantages of simple mechanism, compact structure, simple and convenient installation, high control, low occupation, light weight, low cost, energy conservation, environmental friendliness and the like, and can be widely applied to low-yield and low-efficiency wells, thickened oil wells and production wells in edge areas.

The invention discloses a position sensor-free control apparatus and a position detection method. The apparatus that is applied to a permanent magnet motor comprises: a current determination unit, which is used for determining a q-shaft current value I q of the permanent magnet motor at T1 time; a shaft error detection unit, which is connected with the current determination unit and is used for receiving the q-shaft current value I q and determining a shaft error delta theta of the permanent magnet motor at the T1 time at least based on the q-shaft current value I q, an induced voltage constant setting value Ke* of the permanent magnet motor and a q-shaft inductance value L q* of the permanent magnet motor; and a position detection unit, which is connected with the shaft error detection unit and is used for determining a position theta c of a rotor of the permanent magnet motor at the T1 time based on the shaft error delta theta.

The invention discloses a fuel cell composite power supply system and a control method, which belong to the field of fuel cells and can realize the lowest hydrogen consumption of the whole system andimprove the efficiency and the service life of the whole system. The system comprises a fuel cell module, a super capacitor module, a battery module, a data collecting module and a composite power supply controller, wherein the fuel cell module is used for providing a main power source for a vehicle; the super capacitor module is used for providing transient peak power for the vehicle; the batterymodule is used for supplementing remaining vehicle requirement power; the data collecting module is connected with the fuel cell module, the battery module, the super capacitor module and a load module respectively; and the composite power supply controller realizes optimal distribution of current to the fuel cell module, the battery module, and the super capacitor module according to the collected state information of the battery module, the super capacitor module, the fuel cell module and the load module and based on the minimum hydrogen consumption strategy considering a penalty coefficient.

The invention provides a rail pressure control method and control system based on flow valve current. The method includes the steps: calculating basic target rail pressure as shown in the specification; correcting the target rail pressure; calculating and judging common rail pressure difference; calculating target driving current of a flow valve; calculating duty ratio; controlling flow valve opening; outputting PWM (pulse-width modulation) wave signals to flow valve driving hardware, controlling flow valve opening and adjusting the quantity of fuel entering a common rail pipe from a high-pressure oil pump metering unit when the common rail pressure difference devi controlled for the i time is smaller than Ps and a target PWM wave duty ratio Duty 2i controlled for the i time is equal to Duty 2i-1; i=i+1 and circularly executing the steps S1 to S6 when i is smaller than N; finishing when i is equal to N or an ECU (electronic control unit) receives stop commands. Power-on currentsampling precision can be improved, high voltage is used for driving at a starting stage, generation of induced electromotive force is inhibited by a differentiating circuit, the current of the flowvalve can reach a preset value in a short time by the aid of the certain opening, current response time is shortened, internal resistance temperature compensation is performed on an electromagnetic coil, and interference caused by internal resistance change is reduced.

The invention discloses a cement combination semi-finishing grinding optimization control system. The cement combination semi-finishing grinding optimization control system comprises a data acquisition subsystem, a data analyzing subsystem, a DCS control subsystem, and a centralized control subsystem. The data acquisition subsystem is used to acquire parameters of cement production key equipment in DCS and particle size parameters analyzed and processed by a particle size analyzer. The data analyzing subsystem is used to determine whether cement particle size distribution is reasonable according to data acquired by the data acquisition subsystem, and according to the cement particle size distribution condition, the cement production key equipment is selected to be adjusted, so that the cement particle size tends to be normal, and by using the data analyzing subsystem, the adjusting amplitude of the cement production key equipment is provided. The cement key equipment is adjusted by the DCS control subsystem according to a result acquired by the data analyzing subsystem, and therefore objects of reasonable cement particle size distribution and stable quality are achieved. The invention also provides a cement combination semi-finishing grinding optimization control method.

The invention provides a control device for grid connection current. Current hysteresis control is combined with SVPWM (Space Vector Pulse Width Modulation) control, and two control methods of detecting grid connection current control and current hysteresis control are switched in real time. When the grid connection current is abnormal, the current hysteresis control is automatically switched, and a grid connection current error is limited in an allowed range. When the SVPWM controller detects that the deviation between the practical three-phase grid connection current and command current is within the allowed range, the SVPWM control mode under the normal situation is switched again. The SVPWM controller effectively reduces the grid connection current fluctuation caused at the moment when the two control methods are switched according to the fact that the detected three-phase current is still operated, and the duty ratio is still updated in real time, thereby obtaining high-quality grid connection current. The device can respond in real time when the grid connection current waveform is abnormal, the grid connection current is controlled to be within the allowed range, a fan system is protected, and the impact on the grid is reduced.

The invention discloses an IGBT buffer circuit. The IGBT buffer circuit includes a clamp unit, a buffer unit and a voltage limiting unit; the clamp unit is connected between the collector of an IGBT and the buffer unit and is used for clamping the transient voltage of the IGBT when the IGBT is in a switched-on state, and preventing electric energy stored by the buffer unit from passing through the IGBT; and the voltage limiting unit is connected between the buffer unit and a load and is used for providing a discharge path to the load for the buffer unit when the IGBT is in a switched-off transient state, and voltage between the collector and the emitter of the IGBT charges the buffer unit through the clamp unit, and limiting the generation of voltage peak in a charging period. The invention further provides a PFC circuit and an air conditioner control system. The IGBT buffer circuit, the PFC circuit and the air conditioner control system of the invention are advantageous in that the IGBT buffer circuit, the PFC circuit and the air conditioner control system can reduce switching loss and protect the IGBT.

The invention provides a DC/DC converter structure for a high-gain fuel cell vehicle and a control method and belongs to the field of power system design and application for new energy vehicles. The DC/DC converter structure comprises an upper bridge circuit and a lower bridge circuit which are symmetrically arranged in structure and are connected in parallel, wherein the upper bridge circuit comprises a first inductor, a second switch tube, a second inductor, a second conducting diode and a first capacitor connected in series; a positive electrode terminal of a fuel cell is connected with a first switch tube through the first inductor and then connected to a negative electrode terminal of the fuel cell; the positive electrode terminal of the fuel cell is connected to a midpoint of the second switch tube and the second inductor through a first conducting diode; and the midpoint of the second inductor and the second conducting diode is connected with the negative electrode terminal of the fuel cell through a third switch tube. According to the DC/DC converter structure, the disadvantage of a low boost ratio of a traditional boost topology is avoided, the disturbance of input voltageto output voltage during wide range variation is offset and the overhigh cost is avoided.

The invention provides a magnetic gear. The magnetic gear includes gear teeth and gear grooves. Each gear tooth includes a first contact surface, a second contact surface and a tooth tip. Each first contact surface is provided with a first magnetic source. Each second contact surface is provided with a second magnetic source. Each tooth tip is provided with a third magnetic source. Each gear groove is provided with a fourth magnetic source. The first magnetic sources and the second magnetic sources are used for generating repulsive force when two magnetic gears engage. The third magnetic sources and the fourth magnetic sources are used for generating attractive force when two magnetic gears engage with each other. The magnetic sources are arranged in the structure of the magnetic gear. Theforce of the magnetic sources facilitates the high-rotating speed drive of the magnetic gear. The magnetic sources arranged on the contact surfaces that the magnetic gears engage with each other areused for generating repulsive forces. The repulsive force among the magnetic sources helps to reduce the resistance and the wear of the magnetic gear and prolong the life of the magnetic gear. The magnetic sources arranged at the tooth tips and the gear grooves are used for generating attractive force, which facilitates the calibration of the engaging positions of the magnetic gear and improve theaccuracy of the drive of the magnetic gear.

The invention discloses a dead zone compensating method which comprises the following steps of detecting the phase voltage signal zero crossing point of a power grid, and when the current value of the power grid is equal to a preset current threshold, determining the voltage parameter of the power grid; during the phase voltage signal zero crossing point of the power grid, detecting the parameter of each phase voltage of the current power grid; calculating the ratio of the currently detected parameter of each phase voltage to the determined voltage parameter of the power grid, and taking the ratio as a compensating factor of the phase; determining the compensation value of each phase voltage by adopting the compensating factor of each phase, and compensating an output voltage by utilizing the compensation values of three phases. By adopting the compensating method disclosed by the invention, the compensation effect is better than that of the prior art; after compensation, the content of current harmonics is reduced, the voltage is stable, and the current fluctuation is small.

The invention discloses a wheel hub motor. The wheel hub motor comprises a motor shaft, a stator, a rotor and a position detection device; the position detection device comprises a PCB (printed circuit board) and a magnetic ring; the PCB is provided with a plurality of magnetic induction components; when the magnetic ring is stationary or rotating, the magnetic induction components can sense the change of the magnetic flux of the magnetic ring; the rotor is provided with a left end cover and a right end cover which is used for installing a brake assembly; and the position detection device is arranged inside the right end cover. The invention also discloses an externally-arranged wheel hub motor; the rotor of the external wheel hub motor is provided with a left end cover and a right end cover which is used for installing a brake assembly; a motor shaft at the external side of the left end cover is provided with a housing; and a position detection device is arranged in the housing. The invention also discloses a position signal processing method of the wheel hub motor. The wheel hub motor of the invention has the advantages of simple structure, simple and reliable production process, reliable vibration resistance, low performance requirements for a controller and high accuracy. According to the wheel hub motor, position feedback avoids a heat source, mechanical angle and electrical angle output selections are provided, and the requirements of different control interfaces can be satisfied.

The invention provides a carbon brush holder assembly for a starter, which comprises a brush holder box, a positive pole baseplate and a negative pole baseplate which are arranged on the brush holder box, positive pole carbon brushes, negative pole carbon brushes, springs for driving the positive pole carbon brushes and the negative pole carbon brushes to move, an insulating sheath, a positive pole connecting wire and a carbon brush temporary fixing ring, wherein the brush holder box, the positive pole baseplate and the negative pole baseplate are correspondingly provided with a coaxial hollow hole for a starter rotary shaft to pass through. The assembly is characterized in that three positive pole carbon brushes and three negative pole carbon brushes are respectively welded on the positive pole baseplate and the negative pole baseplate, the brush holder box is formed by one-time injection molding and is provided with three positive pole brush holder grooves and three negative pole brush holder grooves respectively corresponding to the negative pole carbon brushes and the negative pole carbon brushes, the positive pole baseplate and the negative pole baseplate are provided with square grooves which respectively corresponds to the positive pole brush holder grooves and the negative pole brush holder grooves and are used for assembling the springs. A six-brush assembling structure can increase the working performance and prolong the service life. The assembly has a simple assembling process and convenience in assembling, thus improving the assembling efficiency obviously.

The invention provides a novel charger circuit of an electric automobile power battery, which comprises a Z-source AC(alternating current)/AC inverter, a Pi-type filter circuit and an uncontrollable rectifier bridge which are connected in sequence. The Z-source AC/AC inverter is used for converting an alternating voltage, and comprises a Z-source network and two switch elements S1 and S2; one end of the switch element S1 is connected with an AC power supply, while the other end is connected in series with the Z-source network; the switch element S2 is connected in parallel with the Z-source network 11 and connected with the Pi-type filter circuit by a small inductor L0; the Pi-type filter circuit is used for filtering ripple waves in an output voltage, and comprises an inductor Lf and a first capacitor Cf1 and a second capacitor Cf2, which are connected in parallel with the inductor Lf respectively; and the uncontrollable rectifier bridge is connected with the Pi-type filter circuit and used for rectifying an AC signal output by the inverter. The novel charger circuit has the advantages of simple structure, convenience in control, large range of voltage regulation and high speed of voltage regulation, can relieve impact and inhibit harmonic wave, and is suitable for charge application of the electric automobile power battery.

The invention discloses an online estimation method and device for the state of charge and the state of health of a power battery and a storage medium. The online estimation method comprises the steps of 1, collecting the current, the voltage and the temperature of a single battery in real time in the charging and discharging process of the power battery, 2, in the discharging process, identifying parameters of each single battery on line through a recursive least square method with a forgetting factor, 3, estimating the terminal voltage of each single battery by using a Thevenin equivalent circuit model in the charging and discharging process, 4, estimating the SOC of each single battery by using a self-adaptive extended Kalman filtering algorithm, 5, calculating the capacity of each single battery in a charging process, and 6, calculating the battery pack charge state, the battery pack capacity and the battery pack health state, and 7, applying the calculated capacity of each single battery to the capacity parameter of each single battery in the Thevenin equivalent circuit model to realize joint estimation of the state of charge and the state of health of the battery subjected to online closed-loop feedback correction. The method can be used for accurately evaluating the inconsistency state between the battery pack monomers, and provides a basis for formulating a power battery equalization control strategy.

The invention provides a double-rotor motor and an air conditioning unit. The double-rotor motor comprises a stator, an outer rotor and an inner rotor, the stator is fixedly arranged, the stator formsan outer stator section and an inner stator section which are connected along the height direction of the stator, the outer rotor is arranged on the outer side of the outer stator section, and the inner rotor is arranged on the inner side of the inner stator section. By means of the technical scheme, only the stacking height of the outer rotor with the large radius can be increased, the increasedcost is small, and the brought rotational inertia is obviously increased. The moment of inertia of the motor is increased, the torque fluctuation of low-frequency operation of a compressor is reduced, the low-frequency operation current fluctuation is reduced, the current harmonic content is reduced, the compression low-frequency operation rotating speed is more stable, and the efficiency of thecompressor in low frequency operation is enhanced.

The invention relates to an electrical switch device comprising a boost converter switch circuit. The boost converter switch circuit includes an inductor and a first switch (T1), and is used for generating an output voltage (UA) that is higher than an input voltage (UE). The electrical switch device is characterized by being equipped with a second switch (T2) which is used for guiding the inductor in the boost converter switch circuit to genrate currents (iE, iL) when the first switch (T1) is turned off.