3259results about How to "Reduce fever" patented technology

The invention relates to a PFC constant current controller and a control method of the PFC constant current controller. Unlike the traditional mode of additionally adding a PFC circuit besides a PWM controller, the PFC constant current controller integrates a single-stage PFC circuit and the PWM controller. The PFC constant current controller comprises a peak value sampling device, a feedback signal detector, a sigma delta modulator, a digital signal processor, a digital to analog converter, a comparator, a PWM generator and a power switch driver. The PFC constant current controller can obtain sampled signals of current output by a flyback switching power supply system, and the sampled signals serve as feedback signals to generate a constant-current control signal to be used for controlling averagely-output current. Therefore, the averagely-output currents are limited within a preset reference value, and accordingly the target of constant-current control is achieved.

The invention is directed to compositions comprising a nanoparticulate acetaminophen composition, or a salt or derivative thereof, having improved bioavailability. The nanoparticulate acetaminophen particles of the composition have an effective average particle size of less than about 2000 nm and are useful in the treatment of aches and pain, and in the reduction of fever and related conditions.

The invention involving a magnetorheological fluid damping device for automobile suspension system.The magnetic field generator of this damping device consists of permanent magnet and electromagnetic coil.On the top of the damping device,there are guide apparatus and damping regulator,the function of which is that to ensure the damping channel is uniform annular duct and to meet the high-damp requirement in the restoration process and low-damp requirement in the compression process of damper seperately.The current in the electromagnetic coil designs of bi-directional and this controls the magnetic field intersity of the damping channel,decreases the excitation current of the electromagnetic coil,reduces energy consumption and decreases damper fever.On the non-controlling conditions,this damping device has the equivalent characteristics of the traditional shock absorber and can instead the passive shock absorber,after equiping corresponding current controller,this device can regulate the damping characteristics of suspension system,which improves the automobile driving safety and ride comfort.

The invention discloses a single / multi-layer magnetic conductive sheet for wireless charging and a preparation method thereof. The single-layer magnetic conductive sheet comprises a layer of magnetic slice. Multiple strips of cracks are uniformly distributed on the slice and divide the slice into multiple fragment units. Gaps of the cracks are filled with insulation medium, so fragment units on two sides of the cracks are mutually insulated. The single-layer magnetic conductive sheet also comprises a double-faced adhesive tape which is adhered to one face of the magnetic slice. A protection film formed by the insulation medium is formed on the other face of the magnetic slice. The preparation method comprises steps of heat treatment, adhesion of the double-faced adhesive tape, crack processing, gum dipping processing and drying and curing processing. According to the invention, inductance value and quality factor of a charging coil are increased, charging efficiency is increased and loss is reduced. The continuously prepared magnetic conductive sheet is characterized by controllable magnetic conductivity, continuous production, convenient operation and simple insulation processing.

The invention provides an anti-unmanned aerial vehicle detection system and a control method thereof. The system comprises a camera provided with an optical lens, a displayer, an automatic tracking servo mechanism controlling the camera to move, a radar device, a main controller, an interference unit, and an image identification decoder storing unmanned aerial vehicle image information. By the adoption of a photoelectric surveillance radar device combining the radar device with an optical tracking system, radar detection, optical image identification and electromagnetic interference are integrated, and the system and method play an important role in improving organic integration of unmanned aerial vehicle monitoring, the optical system and the radar device.

The invention discloses a lithium battery pack SOC (state of charge) equalization system and a lithium battery pack SOC equalization method. The equalization problems of lithium battery packs are divided into two levels, including intra-group equalization and intergroup equalization. Lithium batteries are divided into a plurality of groups, every lithium battery group is in parallel connection with a bidirectional DC-DC converter, the output ends of the bidirectional DC-DC converters are in series connection to serve as the output ends of a direct-current bus and a power generation system, and loads are in parallel connection. The batteries in every group are connected through bilateral switches and are in parallel connection with by-pass switches so as to be connected dynamically. Intergroup equalization is achieved by distributing output voltage of every group according to average SOC thereof; intra-group equalization can be achieved by controlling dynamic connection of every single battery in every group. The lithium battery pack SOC equalization system and the lithium battery pack SOC equalization method have the advantages that lithium battery pack SOC is equalized without an extra equalization circuit, so that energy transfer among the batteries is avoided, lithium battery pack equalization is achieved automatically in a charge-discharge process, the equalization speed is greatly increased and the equalization efficiency is greatly improved.

An excavator energy-recuperation system relates to an excavator moving arm energy saving system, comprising a hydraulic cylinder, a fuel tank, a quantitative pump, a valve and an engine. The key technology is that a first variable pump and a speed determining photoelectric encoder are coaxial equipped with the quantitative pump. One end of the quantitative pump is connected with a hydraulic cylinder through a reversing valve and the other end of the quantitative pump is respectively connected with the fuel tank and the hydraulic cylinder on two branches. One end of the first variable pump is connected with the fuel tank and the other end is connected with an accumulator through the reversing valve. A second variable pump is coaxial arranged with the engine, one end of the second variable pump is connected with the fuel tank and and the other end is connected with a check valve; a fuel outlet of the check valve has three branches, wherein the first one is connected with the accumulatorthrough the reversing valve; the second one is connected with a hydraulic cylinder through the reversing valve; and the third one is connected with a hydraulic cylinder through the reversing valve. The invention combines the flow regeneration and potential energy recuperation, thus simultaneously realizing the flow regeneration and the energy-recuperation recycling, improving the utilization rateof the excavator energy and prolonging the service life of the excavator.

The invention relates to a track conversion device suitable for a hospital logistic transmission system. A shunting positioning system of a logistic trolley track comprises a device support, a drive motor and a displacement inductor, wherein the drive motor is a serve motor and connected with one end of a screw rod through a coupler, track change is achieved for a trolley through a relay track, the initial position of the replay track is respectively matched with an initial track on which the trolley runs and a target track, a support slide rail perpendicular to the initial track is arranged below a track support used for bearing the relay track, the relay track is welded to the track support, a transverse rod of the track support is provided with a threaded mechanism which is matched with a threaded mechanism on the screw rod, and the screw rod and the track support form linage integration through the threaded mechanisms. The shunting positioning system of the logistic trolley track solves the problems that an existing shunting positioning system of the logistic trolley track is large in error of track change butt joint and severe in damage to a motor, and is high in accuracy and low in loss of the motor.

The invention relates to an air floatation high-speed electric main shaft, in particular to an air floatation high-speed electric main shaft for a machining tool. A lower air bearing block assembly 7 is fixed on a thrust bearing 9, the upper part of the lower air bearing block assembly 7 is provided with a stator 6, the front end of a shaft core 5 is provided with a chuck accessory 11, an aluminum water jacket assembly 3 is fixed at the upper opening of a body assembly 10, and a tool changing cylinder assembly 1 is fixed on the upper part of the aluminum water jacket assembly 3; and the middle part of the shaft body of an upper air bearing 4 is provided with an upper air bearing cooling water passage 12. The main shaft is an electromechanical integrated base piece with high revolution number and high precision, has simple and compact structure, and is convenient to install, high in heat dissipation efficiency, multifunctional and convenient for popularization and application.

The invention discloses a digital electric-hydraulic synchronous control system, which comprises a hydraulic actuating mechanism, a digital synchronous control mechanism for performing synchronous control on the hydraulic actuating mechanism, an electric-hydraulic power source for providing power oil for the hydraulic actuating mechanism and the digital synchronous control mechanism, and an electric-hydraulic control system for controlling the power source and the synchronous control mechanism. The hydraulic actuating mechanism is a hydrocylinder; the electric-hydraulic power source comprises an oil storage tank, a double-acting hydraulic oil pump and a driving motor; the electric-hydraulic control system comprises a detector for detecting the oil pressure of the hydraulic oil pump and the rotating speed of the motor respectively and a variable frequency speed regulator and a controller for controlling the motor; and the digital synchronous control mechanism comprises a digital synchronization valve, a digital synchronization controller and a displacement transducer for detecting the displacement of an output shaft of the hydrocylinder. The digital electric-hydraulic synchronous control system has the advantages of simple structure, simple and convenient use and operation, good use effect, energy conservation and no oil leakage, and can achieve the aims of stepless speed regulation and high-precision synchronization according to operating characteristic requirements of different types of controlled objects.

The invention discloses a rapid charging system and method based on a USB PD protocol. The system comprises an adapter and a power utilization device; the adapter comprises a first input port, a first output port and a voltage transformation rectification filter voltage stabilizing circuit, and the voltage transformation rectification filter voltage stabilizing circuit comprises a first data processing chip which is based on the USB PD protocol and in data communication with the power utilization device; the power utilization device comprises a second input port connected with the first output port, a rechargeable battery and a charging control circuit, and the charging control circuit comprises a second data processing chip which is based on the USB PD protocol and in data communication with the adapter, a BUCK voltage conversion circuit and a constant current charging circuit; both the first output port and the second input port are Type C standard USB ports or Micro USB ports. According to the rapid charging system and method, the power utilization device directly adjusts the magnitude of the output voltage of the adapter through the USB PD protocol to make the adapter enter a constant current output work mode of the designated parameter, charging efficiency is high, and the power loss and heating in the power utilization device are lowered.

The invention discloses a novel inflatable switch cabinet which comprises a cabinet body. A gas tank is arranged on the rear side of the cabinet body, a control chamber is arranged on the upper portion of the front side of the cabinet body, a cable chamber is arranged on the lower portion of the front side of the cabinet body, a vacuum breaker is arranged on the upper portion of the gas tank, an isolating switch is arranged in the middle of the gas tank, a main loop is arranged on the lower portion of the gas tank, and an isolating switch operating mechanism and a vacuum breaker operating mechanism are arranged in the control chamber. The isolating switch operating mechanism achieves switch-on, switch-off and ground connection of a disconnecting link by operating a first operating shaft and a second operating shaft, and power-driven operation can be achieved. The vacuum breaker comprises an insulation support, a vacuum bubble and an operating main shaft, the vacuum bubble is arranged in the insulation support in the mode with an upward dynamic contact, a conductive contact and a conductive piece are fixedly arranged on the lower portion of the insulation support and are fixedly connected with a static contact at the lower end of the vacuum bubble, the conductive contact and the disconnecting link are matched for switch-on, and the operating main shaft drives the dynamic contact at the upper end of the vacuum bubble to vertically move to achieve switch-on and switch-off of the vacuum breaker. The novel inflatable switch cabinet is compact in structure, reliable in motion, safe in use and convenient to maintain.

The invention discloses a thermostatic gas water heater controller, characterized by comprising a signlechip, a gas valve drive / detection circuit, an igniter control / flame detection circuit, a blower drive / feedback circuit, a gas proportion valve drive / detection circuit, an air pressure detection circuit, a water flow sensor circuit, a water inlet / outlet temperature sensor circuit and an overheat protection circuit. The gas valve drive / detection circuit also comprises a gas valve drive circuit and a valve detection circuit, and the igniter control / flame detection circuit further comprises an igniter control circuit and a flame detection circuit. The invention aims to overcome the shortcomings of low control accuracy, high failure rate and poor interference resistance of a traditional controller, and provide the thermostatic gas water heater controller with reliable control, low failure rate and no current surge.

The invention relates to the electrotechnical field, in particular to an induction electricity getting device for a high-voltage power transmission line. The invention solves the problem that the application effect of the existing power supply realized through induction electricity getting by using current on the high-voltage power transmission line is not good. The induction electricity getting device comprises a ring iron core, a secondary coil and an output regulation circuit. The output regulation circuit comprises a rectification circuit, a pulse width modulation circuit, a voltage sampling circuit, a current division branch circuit, an anode output line terminal and a cathode output line terminal, wherein the current division branch circuit is formed by a switch-type power device and a resistor connected in series; the anode terminal of the rectification circuit is connected with the anode output line terminal through an isolation diode; and the pulse width modulation circuit and the voltage sampling circuit are connected in parallel between output line terminals. The sampled signal input end of the pulse width modulation circuit is connected with the output end of the voltage sampling circuit. A driving pulse output end is connected with the control end of the switch-type power device. The induction electricity getting device can effectively adjust the electric energy obtained through the induction of the high-voltage power transmission line and can ensure the stability of the electric energy provided to external loads.

The invention discloses a plunger pump type hydraulic injection moulding machine system driven by a servo motor. The system comprises an oil tank, a servo pump, a mould height motor, a mould clamping cylinder, an ejector cylinder, a movable ejection cylinder, a glue-ejecting cylinder, a glue-smelting motor and an electronic ruler measurement sensor and also comprises a computer controller, a pressure and speed comprehensive control module, a servo driver, the servo motor and a pressure sensor. The invention also discloses a control method of the plunger pump type hydraulic injection moulding machine system driven by the servo motor. In the control method, the pressure sensor and the torque control of the servo motor are adopted, the multilevel control of pressure and flow can be realized;real-time closed-loop control is adopted to control the pressure and flow during injection moulding; and in the control process, the instructions on the pressure and flow are compared with feedbacks in real time and some parameters such as the speed, pressure and current at each moment are controlled accurately, thus effectively realizing technical motions such as the mould open / closing, ejection, glue ejection and glue smelting of the injection molding machine and the closed-loop follow control of the oil cylinder. The method of the invention has the advantages of high precision, high speed and efficiency, energy-saving, environmental friend, low noise and the like.

The invention relates to a digital loudspeaker drive method and a device based on quaternary code dynamic mismatch reshaping. The method comprises the steps of (1) conducting input format conversion, (2) conducting multi-bit sigma to delta modulation, (3) conducting thermometer code conversion, (4) conducting dynamic mismatch reshaping processing, (5) conducting channel data combination and mapping coding, (6) controlling metal-oxide-semiconductor field effect transistor (MOSFET) pipe of a full-bridge power amplifier network to conduct opening and closing status switching, and driving a digitalized loudspeaker load to produce sound. The device comprises a sound source (1), a digital format converter (2), a multi-bit sigma to delta modulator (3), a thermometer coder (4), a dynamic mismatch reshaper (5), a channel data combiner (6), a mapping coder (7), a multi-channel digital amplifier (8) and the digitalized loudspeaker load (9). The units are sequentially connected in order. According to the digital loudspeaker drive method and the device based on quaternary code dynamic mismatch reshaping, use efficiency of an amplifier pipe and the load is improved, development periods and hardware implementation cost are saved, and good immunity is provided for frequency response deviation of digital channels.

The invention discloses a charging method. The method comprises the following steps: detecting current input by a mobile terminal; sending out a communication signal to a charger by the mobile terminal; if communication established between the mobile terminal and the charger is successful, collecting battery parameters by the mobile terminal; determining corresponding charging parameters according to the collected battery parameters by the mobile terminal; and sending the charging parameters to the charger by the mobile terminal. The charger can charge a battery according to the charging parameters determined in the mobile terminal; when the temperature of the battery is relatively low and lower than a threshold value and the potential safety hazard is relatively low, quick charging can be carried out by using high voltage and high current, so that the charging efficiency is quickened; and when the temperature of the battery is relatively high or when the battery is ready to be full, charging can be carried out by using safer voltage and current, so that the heating of the battery is reduced, and the safety of the battery is improved. The invention also discloses a charging device and a charger.

The invention provides a compact axial-flow magnetic-levitation artificial heart pump, in particular to an artificial heart pump characterized in that two permanent magnet bearings and a mix of radial magnetic bearing suspension, and the radial magnetic bearing and a permanent magnet motor share a stator and a rotor. The compact axial-flow magnetic-levitation artificial heart pump has the structure that the compact axial-flow magnetic-levitation artificial heart pump comprises a stator assembly, a rotor assembly, a front guidance impeller and a rear guidance impeller; a taper-shaped or axial permanent magnet bearing is respectively formed by a first permanent magnet (9) and a right permanent magnet ring (14) as well as a second permanent magnet (19) and a left permanent magnet ring (18) to realize the purpose that the rotor axially supports in a suspension mode; a torque coil (5) and a suspension coil (7) are respectively wound on a motor stator (6); and with a certain decoupling control algorithm, the motor stator not only generates torque force but also generates radial suspension support force. In the compact axial-flow magnetic-levitation artificial heart pump, the rotor is supported by permanent magnetic force and electromagnetic force, and the compact axial-flow magnetic-levitation artificial heart pump has the advantages of small damage on blood, less radiation, compact structure and the like, is easy to transplant, is suitable for patients suffering from cardiac function failure, heart diseases and the like and can be used for ventricular assisting for a long time or a short time.

The present invention aims to improve bond durability as well as rate characteristics, cycle characteristics and short-circuit ratio of a secondary battery by decreasing the internal resistance of a secondary battery electrode. Specifically disclosed is a binder for secondary battery electrodes, which is composed of a polymer obtained by polymerizing a monomer composition containing a fluorine atom-containing monomer represented by the general formula (I) below and having a weight average molecular weight of 5,000-2,500,000. In the formula, R<1> represents a hydrogenor a methyl group, and R<2> represents a fluorine atom-containing hydrocarbon group having 6-18 carbon atoms.

The invention designs an automatic temperature control circuit which has exact control, reliable and stable performance and complete protective measures, and is used for executing effective real time control on the temperature of a tube core of a pump laser in ASE broadband light source. The control device adopts the design proposal of a temperature control system based on Proportion Integration Differentiation (PID) control and pulse-width modulation (PWM) braking mechanism and realizes the designs by adopting a pure hardware circuit; the control device comprises a reference voltage circuit, a pumping tube core temperature testing circuit, a thermoelectric voltage amplifier circuit, a PID controller, a pumping refrigeration current limiting protective threshold set circuit, an efficient PWM control driver, a pumping semiconductor refrigerator and a pumping tube core temperature out-of-limit close protective circuit. The whole circuit has simple and compact design, high reliability as well as heating and refrigerating efficiency, and little self heating, thereby greatly reducing the power consumption and volume of a pumping temperature controller; as the control device has the complete protective function, when the temperature of the pumping tube core exceeds the set range of operating temperature, the circuit sends out the gang control signal to automatically close a drive circuit of the pumping. The pumping refrigeration current limiting protective circuit limits the refrigeration current within the range of the preset maximum refrigeration current range to prevent the pumping from being damaged.

PROBLEM TO BE SOLVED: To provide an LED driving device which can drive an LED by constant current, reduce heat generation of a circuit element group including LEDs by optimizing voltage to be supplied to the LED, and stably light a backlight unit during light controlling. ŽSOLUTION: In the LED driving device, a first negative feedback closed loop CL1 for controlling supply voltage is comprised of a DC / DC convertor 8, an output driving element 10, a voltage comparison circuit 12, and an output voltage control circuit 13, and a second negative feedback closed loop CL2 for controlling constant-current is comprised of an output driving element 10 and a constant-current control circuit 11. The frequency response characteristic of the first negative feedback closed loop CL1 for controlling supply voltage is set to 1 / 20 or less of that of the second negative feedback closed loop CL2 for controlling constant current, so that the first negative feedback closed loop CL1 for controlling supply voltage can be stably operated without spoiling the response of controlling the constant current. Ž

A device and method for providing body cooling for treating fever. The cooling device applies cooling to blood flowing in a vein or artery, e.g., the vena cavae, that is then distributed throughout the body.

The invention discloses a battery state-of-health (SOH) optimization control method for a modular multilevel battery energy storage system, comprising the following steps: determining the relative SOH of all battery packs by measuring the rate of change in state of charge of the battery packs; presetting a state-of-charge change curve of each sub module battery pack; and balancing the SOH of all the battery packs in the charge / discharge state of the energy storage system according to the proportion of real-time input / output power assigned to different battery packs in the total power, and finally narrowing the difference between the battery packs in SOH. When the performance of an individual battery pack decreases, the discharge ratio and the discharge depth of the battery pack can be reduced by controlling corresponding modules of an MMC, and therefore, the battery pack is protected. Moreover, the thermal management requirement of the modular multilevel battery energy storage system is lowered.

The invention discloses a charging circuit, a charging system, a charging method and a terminal. The charging circuit comprises a control module, a charge pump conversion module, a step-down conversion module, and a battery module. The control module is used for collecting the voltage and current of the battery module and sending control signals to the charge pump conversion module and the step-down conversion module according to the voltage and current so as to switch power-on states of the charge pump conversion module and the step-down conversion module. The control signals comprise a first control signal used for controlling the power-on of the charge pump conversion module and the power-off of the step-down conversion module and a second control signal used for controlling the power-on of the step-down conversion module and the power-off of the charge pump conversion module. Since the charge pump conversion module with high efficiency is used, the step-down conversion efficiency is improved, and charging heating is reduced.

The invention discloses a compound magnetic conductive plate used for wireless charging and near field interference resistance and a preparation method thereof. The compound magnetic conductive plate comprises a top-layer material, a middle-layer material and a lowest-layer material, wherein the top-layer material and the lowest-layer material are both compound slices compounded by soft magnetic powder and resin materials; the middle-layer material is a combination body of at least one layer of magnetic metal slice or a compound slice combined by a magnetic metal slice and the soft magnetic powder and the resin material, wherein one surface or two surfaces of the magnetic metal slice are adhered with double faced adhesive tape; the top-layer material, the middle-layer material and the lowest-layer material are subjected to one-time forming after being subjected to hot pressing. When an NFC (Near Field Communication) function is carried out, enough permeability is provided so as to guarantee an enough communication distance and meet NFC requirements; meanwhile, the NFC function can be prevented from disturbing other processors. Correspondingly, other processors can be prevented from distributing an NFC antenna.

The invention relates to a digital soft switch inverter arc welding machine which is controlled by an embedded system. The digital soft switch inverter arc welding machine mainly solves the technical problems of the deficiencies on the control performances and the dynamic response aspect of the traditional welding machine, difficult realization of the real-time control of the welding arc and the improvement of the reliability of an inverter welding machine and so on. A main circuit is controlled by a control circuit to realize the arc welding, the pulse width modulation adopts a soft switch phase-shifting circuit; a pulse drive and protection circuit adopts a drive two magnetic tank type pulse transformer, a capacitor, a twisted-pair line, a TVS tube and a resistor are simultaneously added for continuous protection, thus preventing over-voltage and misconduction of IGBT which is caused by the over-voltage. The digital soft switch inverter arc welding machine is mainly used for various welding.

The invention relates to a method for recording and searching hard disk video having analog tape serial mode, which is characterized in that the method comprises the process of establishing disk track files in advance, video tape data buffering serial write procedure, token management process ensuring preferential writing and process of quickly searching and reading video tape data. The method has the advantages that 1) a disk preallocation mode is used for solving the problem of disk defragment generated by establishing and deleting files temporarily, so that the service life of the disk is prolonged. 2) As the operation of establishing and deleting files is not involved in the processing of using the disk, the probability of damaging the disk can be greatly reduced in certain extreme cases. 3) Data buffering technology, serial writing technology and track file technology are used for decreasing the operating times of the disk and the moving frequency of a magnetic head to the utmost extent, reducing the heat rise of the disk and prolonging the service life of the disk. 4) By adopting the token technology, the method better adapts to the requirements for ensuring the normal work of the video tape in the application of video surveillance.

The invention relates to a safety brake and redundancy control system of a mine hoist. Detection signals of a roller rotation speed sensor and a motor rotation speed sensor are input into a speed redundancy detector, the processed detection signals are input into a speed signal comparer, compared with a command signal, and then input into a speed closed-loop controller, the speed closed-loop controller transmits the signals to a pressure signal comparer and a pressure feed-forward controller, the pressure signal comparer compares a signal of a pressure sensor and an output signal of the speed closed-loop controller, a comparison result is input into the pressure speed closed-loop controller, and a signal of the speed closed-loop controller is input into an adder through a switch to form a control signal of a tee proportional depressurization valve; and when the pressure sensor is cut off, the output signal of the speed closed-loop controller is input into the adder after being processed by the pressure feed-forward controller, and an output signal of the adder controls the tee proportional depressurization valve, so that the braking torque is controlled. The safety brake and redundancy control system is high in control precision and response speed, and the mine hoist can brake at constant retarded velocity.

The invention discloses a repetitive-control-based method for controlling a compensation current of a DSTATCOM (Distribution Static Synchronous Compensator). The method comprises the following steps of: (1) acquiring a grid voltage, a load current and the compensation current; (2) extracting current commands from the load current; and (3) carrying out repetitive control and PI (Proportional-Integral) control according to the current commands, and then, outputting voltage commands to the DSTATCOM. According to the repetitive-control-based method for controlling the compensation current of the DSTATCOM, the no-static-error tracking of the low-order harmonics, comprising fundamental harmonics, of the DSTATCOM can be achieved, the compensation accuracy of the DSTATCOM is improved, the compensation bandwidth of the DSTATCOM is increased, and the compensation capability and accuracy of the DSTATCOM with unbalanced loads are improved, so that the DSTATCOM can have harmonic compensation and suppression capabilities, the use of passive filters at the outlet side of the DSTATCOM is reduced, the harmonic performance of the compensation current of the DSTATCOM is improved, the harmonic output is reduced, and the pollution to a power grid is reduced.