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

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 the same 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.

An attitude control-based sole glue spraying path planning method of the present invention mainly comprises a robot, a laser profile measurement instrument, a glue gun and an industrial control computer. By using the laser profile measurement instrument to scan a sole, the three-dimensional point cloud of a sole curve is obtained, after the data is processed, a glue spraying path is planned, a control program is generated on the industrial control computer to be introduced into the robot, and the attitudes of the glue gun at the tail end of the robot are controlled according to different shoe types, so that a glue spraying process of the sole is finished, the attitudes of the glue gun can change along with the slope of a sole profile fitting curve, and the attitudes of the glue gun at the tail end of the robot can be controlled according to the different shoe types. Moreover, the glue spraying path of the present invention is smoothed, so that the commutation times of a robot motor can be reduced, and the operation speed of the robot is improved, and accordingly, the glue spraying efficiency is improved, and the working service life of the robot is prolonged.

To provide a space vector modulation method for a matrix converter which uses only one carrier for three phases upon carrier comparison. Provided is a matrix converter space vector modulation method which PWM-controls bidirectional switches (SW1 to SW9) of a matrix converter (3) by space vector modulation from a multi-phase AC power source. A switching pattern using a virtual indirect space vector is converted into a switching pattern formed by a combination of five vectors using direct conversion space vectors. Among the converted switching patterns, a switching pattern satisfying a predetermined condition is selected and duties of the five vectors of the selected switching pattern are calculated by using a duty relationship expression of the direct conversion space vectors. The matrix converter is PWM-controlled according to the calculated duties.

The invention discloses a fracturing pump system and a fracturing truck. In the fracturing pump system, a first conveying mechanism and a second conveying mechanism comprise oil cylinders, supercharging cylinders and distribution valves. Each distribution valve comprises a first channel, a second channel and a third channel, wherein the first ends of the first channel, the second channel and the third channel are connected, a suction valve is arranged in the second channel, and a discharge valve is arranged in the third channel. Plug bodies are arranged at the extending end of piston rods of the oil cylinders and movably arranged in the supercharging cylinders, and outlets of the supercharging cylinders are connected with the second end of the first channel. An engine is used for driving an oil pump. A control valve group is used for controlling oil inlet and return states of the oil cylinders. By using the fracturing pump system, a stroke can be effectively increased, stoke times can be decreased, the service life of easily damaged parts can be prolonged, an output pressure and flow coverage range can be effectively widened, the structural complexity can be effectively reduced, the cost can be saved, and the lubrication and cooling requirements can be effectively 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 provides a piston motion speed matching method for improving concrete pumping material suction performance. The piston motion speed matching method mainly comprises the steps that (1) the rotating speed of stirring blades in the concrete material suction process is given, the average torque T0 of the stirring blades at the rotating speed is measured through a torque sensor, then the optimal speed of piston motion is calculated and corrected, and the piston motion speed is adjusted through a feedback adjusting module; and (2) the piston material suction motion speed is divided into three stages, namely the piston accelerated motion stage, the piston uniform motion stage and the piston decelerated motion stage. When the concrete fluidity is good, the motion speed of a piston can be increased, and the material suction frequency of the piston in unit time is increased while the material suction performance is guaranteed; and when the concrete fluidity is low, the motion speed of the piston can be decreased, the material suction amount is increased, the reversing frequency of an S pipe is decreased, abrasion of eye rings and other quick-wear parts is reduced, and energy consumption is reduced.

The invention provides a modulation method for improving the current stress of a quasi-Z-source inverter switching device, and the modulation method comprises the steps: subtracting the maximum valueof saddle waves from saddle waves of a conventional voltage space vector modulation SVPWM with the phase difference of 120 degrees to obtain three modulating waves, wherein the maximum value of three-phase saddle waves is a straight line according to the converted waveform, and translating the straight line upwards for M/2, wherein M is the distance between the maximum value and the minimum valueof the modulated wave after the modulated wave and the triangular carrier wave are subjected to per-unit processing between 0 and 1. According to the modulation method, the gate-level signal generation process is simple, the switching loss is low, no low-frequency alternating-current component exists on the input direct-current side, the current stress of the switching device is greatly reduced, and the service life of the switching device is prolonged.

The invention discloses a smoke exhaust system and a side-draft range hood. The side-draft range hood comprises the smoke exhaust system. The smoke exhaust system comprises an air cabinet, a smoke collecting hood and a fan, wherein a first containing cavity is formed in the air cabinet, a first smoke exhaust port is formed in the top of the air cabinet, and a first smoke inlet is formed in the rear side of the bottom of the air cabinet; the smoke collecting hood is arranged at the bottom of the air cabinet, a smoke collecting cavity is formed in the smoke collecting hood, a second smoke inlet is formed in the front side of the smoke collecting hood, and a second smoke exhaust port connected with the first smoke inlet is formed in the top of the smoke collecting hood; and the fan is arranged in the first containing cavity, a first air inlet and an air outlet are formed in a shell of the fan, the first air inlet is located in the rear side of the shell of the fan, the air outlet is connected with the first smoke exhaust port, and the included angle alpha between the plane where the first air inlet is located and the horizontal plane is an obtuse angle. By the adoption of the structure, the number of times of reversing before cooking fume enters the first air inlet is reduced, the flowing efficiency before the cooking fume enters the first air inlet can be improved, and thus the effect of sucking away the cooking fume in the cooking environment is improved.

The invention provides a multiphase flow separate transportation processing device which comprises a mixed transportation mechanism, the mixed transportation mechanism comprises a first tank body, a second tank body, a third tank body and a reversing mechanism, the first tank body and the second tank body communicate with the third tank body, the first tank body and the third tank body form a first processing mechanism, and the second tank body and the third tank body form a second processing mechanism; the reversing mechanism communicates with the first treatment mechanism and the second treatment mechanism; and the distributing and conveying mechanism is connected with the first tank body, the second tank body and the third tank body so as to distribute and convey gas and/or liquid with different densities separated from the first tank body, the second tank body and the third tank body. And by arranging the third tank body, the treatment capacity of the crude oil mixture before reversing can be increased, so that the reversing times in the separation and transportation treatment process are reduced, and the damage to internal equipment of the device caused by impact during reversing is reduced.

The invention discloses a light source device and a light path switch, the light path switch comprises a power supply, a control assembly and an execution assembly, the power supply, the control assembly and the execution assembly are connected with one another, the execution assembly is arranged on one side of a light path and comprises a light blocking part and a stepping motor, and the stepping motor is connected with the light blocking part and used for driving the light blocking part to rotate so as to open or close the light path; the light blocking part is provided with a fixed end and a movable end, the fixed end is connected with the output end of the stepping motor, and the movable end extends outwards in a certain radial direction of the stepping motor to form a light blocking part; the stepping motor comprises a rotor, a first winding and a second winding, the first winding and the second winding are at least arranged in the certain circumferential direction of the outer side of the rotor, the control assembly is connected with the first winding and the second winding, and the stepping motor is driven to rotate by controlling the direction and the magnitude of currents in the first winding and the second winding. Therefore, the light blocking part is driven to rotate so as to enable the light blocking part to block or avoid light rays. The light path switch has the advantages of high switching speed and low power consumption.