33results about How to "Reduce the number of commutations" patented technology

In order to provide a space vector modulation method for a matrix converter, the method uses only one carrier for three phases when carrier comparison is performed. The provided method is a matrix converter space vector modulation method in which the bidirectional switches (SW1 to SW9) of the matrix converter (3) are PWM controlled in space vector modulation from a polyphase AC power supply. The switching mode for which the virtual indirect space vector is used is converted to the switching mode for which the direct conversion space vector composed of five vectors is used. Any one of the transformation switching patterns satisfying a predetermined condition is selected, and using the load relation formula between the virtual indirect transformation space vector and the direct transformation space vector, the loads of the five vectors of the selected switching pattern are calculated. Then, the matrix converter is PWM controlled based on the calculated load.

The present invention is a planning method of spraying glue path for soles based on attitude control, which mainly includes a robot, a laser profile measuring instrument, a glue gun and an industrial computer. The laser profile measuring instrument scans the sole to obtain a three-dimensional point cloud of the curved surface of the sole. After data processing Carry out glue spraying path planning, generate a control program on the industrial computer and import it into the robot, control the attitude of the glue gun at the end of the robot according to different shoe types, and complete the glue spraying process of the sole, so that the attitude of the glue gun can follow the slope of the sole contour fitting curve to change , the posture of the end glue gun of the robot can be controlled according to different shoe types, and since the glue spraying path of the present invention is smoothed, the number of commutation times of the robot motor can be reduced, the running speed of the robot can be improved, thereby improving the glue spraying efficiency and extending the The working life of the robot.

The invention discloses low-reversing reliability and frequency method for controlling a four-way valve, which comprises control processes under the following use conditions: during heat generation, time A is determined according to an ambient temperature and an unloading electromagnetic valve is turned off at the same time, then the cold air-resistance operation of an indoor fan and an inverter compressor are started, a pilot valve of a four-way wave is turned on to act when the inverter compressor operates for 180+A seconds, and the four-way valve realizes inversion and an outdoor fan operates at the same time; for machine stop during heat generation, the inverter compressor and the outdoor fan are turned off first, then the unloading electromagnetic valve is turned on to allow an exhaust pipe and an intake pipe to be communicated continuously for time B, and finally the pilot valve of the four-way valve is controlled to be turned off to reset and the indoor fan is turned off at thesame time, wherein the time B is between 5 and 15 seconds; and during heat regeneration, the unloading electromagnetic valve is turned off first and the pilot valve of the four-way valve is controlled to be turned on to act at the same time, then the inverter compressor is started, and the indoor fan starts cold air-resistance operation and the outdoor fan starts operation when the inverter compressor operates for 180 seconds.

The invention discloses a defrosting control method for an intelligent air cooling heat pump, belonging to the field of refrigeration and air conditioning. The method comprises the following steps: when an air conditioner is started for heating, a controller detects the outdoor ambient temperature and the temperature of a coiled tube of an outdoor heat exchanger; when the temperature of the coiled tube of the outdoor heat exchanger is lower than the preset frosting temperature of the coiled tube, the coiled tube is judged to be frosted, and the difference between the outdoor ambient temperature and the temperature of the coiled tube of the outdoor heat exchanger at the moment is recorded as the initial frosting temperature difference of the coiled tube; and then the difference between theoutdoor ambient temperature and the temperature of the coiled tube of the outdoor heat exchanger is dynamically recorded and judged, and when the difference between the difference and the initial frosting temperature difference of the coiled tube recorded previously is greater than the temperature difference of a preset allowable frosting thickness, and the operation time of a compressor is longer than the preset unstable operation time of the compressor, the air conditioner enters a defrosting mode. The invention has the beneficial effects that: defrosting is carried out only when frost is formed, the defrosting frequency of the compressor and time for defrosting every time are reduced, an unnecessary defrosting period is reduced, and the effects of saving electricity and prolonging the service life of equipment are achieved.

The invention discloses a one-phase five-level inverter. The one-phase five-level inverter comprises a common ground type three-level switching circuit, a filter circuit and a power frequency inversion circuit. For being realized specifically, the inverter comprises six power switches from S1 to S6, two diodes from D1 to D2, and a one-phase output filter F. The output of the inverter is five levels, and the inverter has the advantages of being high in inversion efficiency and reliability and simple in control mode. Meanwhile, through the voltage clamp mode, the inverter can eliminate high-frequency common mode current danger in a non-isolated type grid-connected inverter system effectively. Thus, the inverter is especially suitable for being applied to a non-isolated type photovoltaic grid-connected system.

The invention discloses a light source device and an optical path switch. The optical path switch includes a power supply, a control component and an execution component, and the power supply, the control component and the execution component are connected to each other. The optical component and the stepping motor connected to it are used to drive its rotation to open or close the optical path. The light blocking component has a fixed end and a movable end, the fixed end is connected to the output end of the stepping motor, and the movable end is along the A certain radial direction extends outward to form a light-shielding part; the stepper motor includes a rotor and at least a first winding and a second winding arranged along a certain circumferential direction outside the rotor, and the control assembly is connected with the first winding and the second winding respectively. connected, by controlling the direction and magnitude of the current in the first winding and the second winding to drive the stepper motor to rotate, thereby driving the light blocking part to block or avoid light. The invention has the advantages of fast switching speed and low power consumption.

The invention relates to a 47-meter R-type foldable arm rack concrete pump truck and a producing method thereof. The 47-meter R-type foldable arm rack concrete pump truck comprises an arm rack system,a power system, a pump sending system, an electric system and a hydraulic system. The 47-meter R-type foldable arm rack concrete pump truck is characterized in that the hydraulic system is provided with a hydraulic element used for checking actual workload transmission, a main oil pump is a variable inclined-disc type axial plunger piston pump, the hydraulic system uses a closed loop, a five-section rolling foldable arm rack is in fulcrum-type R-shaped fold, support legs are JJ-shaped double-swinging telescopic support legs, and a main oil cylinder is of a guiding-sleeve piston-rod sealing structure. The arm-rack system of the product of the invention is controlled by an electric-proportion multi-path valve and remotely controlled by a wireless remote control system. The arm rack oil cylinder has a bidirectional interlock function, effectively guarantees the work safety and the reliability of the arm rack and enables the intelligence of the whole system to be higher. The elements independently work and are not mutually interfered. The product of the invention has the characteristics of energy saving, high effect and low intelligence and worker labor intensity, and can be widely used in the projects of city building, bridges, foundation construction, and the like.

A three-phase three-switch two-level rectifier based on a zero-voltage soft switch includes a three-phase two-level rectification circuit, a resonance circuit and a filter capacitor C, wherein the three-phase two-level rectification circuit includes a first rectification bridge arm, a second rectification bridge arm, and a third rectification bridge arm that are connected in parallel. Compared with traditional three-phase two-level rectifiers, the three-phase three-switch two-level rectifier omits three full-control power devices and corresponding switch driving circuits, and a high power factor unidirectional rectifier has the advantages of reduced number of power switches, short circuit natural protection, small energy processing of an active switch and the like under the condition of not requiring bidirectional power flow; the two-level rectifier has a large advantage in the case of low output voltage; and in addition, compared with a traditional three-level active rectifier, midpoint voltage of a direct current bus does not need to be controlled, the phenomenon of unbalanced neutral point potential is completely eradicated, and the number of sensors and controllers is reduced.

The invention discloses a narrow pulse suppression and electric energy quality improvement method for a matrix converter. The method is characterized in that: the matrix converter adopts double-voltage modulation; and when control signals of six switches for line voltage synthesis have narrow pulses in a certain switching period, six groups of new modulation functions for switch control are reconstructed and calculated according to the positions of the narrow pulses. The new functions are characterized in that: the new functions comprise instantaneous output current detection information; one of the six switches is kept in an off state; and the modulation functions simultaneously meet input current and output voltage modulation requirements. On the premise of no increase of the switching loss and the number of commutation times of the matrix converter, the number of the narrow pulses is effectively decreased, and the input and output waveform quality of the matrix converter is improved; and the method is particularly suitable for middle and high power places in which commutation time is long.

The invention discloses a driving method, system and storage medium of a stepping motor. The method includes: setting the rotation stroke of the stepping motor in advance according to the application scene; The stepper motor accelerates to the middle position of the rotation stroke in two phases, and then drives the stepper motor to decelerate in two phases to the holding position and stops; at the holding position, the single coil maintains; in response to the reverse rotation command, drives the stepping motor to accelerate to the rotation stroke in two phases The middle position, and then drive the stepping motor two-phase deceleration to the initial position to stop. By adopting the method, the stepper motor can be started and stopped quickly and smoothly in a fixed stroke.