CN206432928U

CN206432928U - A kind of single-phase motor variable frequency drive

Info

Publication number: CN206432928U
Application number: CN201720148724.XU
Authority: CN
Inventors: 卢丹; 雷霭迁
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-02-20
Filing date: 2017-02-20
Publication date: 2017-08-22
Anticipated expiration: 2027-02-20

Abstract

The utility model discloses a kind of single-phase motor variable frequency drive.Including the first electronic power switch, the second electronic power switch, the 3rd electronic power switch, the 4th electronic power switch, electric capacity and motor, first electronic power switch, the second electronic power switch constitute a half-bridge, it is connected with the winding U of motor, 3rd electronic power switch, the 4th electronic power switch constitute a half-bridge, are connected with the winding V of motor.The winding common port of U, V two of motor is connected with capacitance cathode, and electric capacity negative pole connects power cathode.The utility model uses variable frequency drives, uses load motor, to simplify manufacturing process, using novel circuit structure form, a fairly large number of deficiency of electronic power switch needed for both having solved conventional ADS driving mode also solves the narrow deficiency of the operation interval of motor Effec-tive Function.

Description

A kind of single-phase motor variable frequency drive

Technical field

The utility model is related to motor-drive circuit technical field, more particularly to a kind of single-phase motor frequency conversion drive electricity Road.

Background technology

Current single-phase ac asynchronous motor, mostly by way of electric capacity phase shift, makes two phase winding on motor stator Produce phase difference and be about 90 degree of sinusoidal current, there is provided the primary condition that motor is operated so as to form rotating excitation field.Above-mentioned motor There is deficiency not in type of drive：

1st, inconvenient speed governing.A point speed governing is carried out by way of tapping, gear is limited, wire winding is complicated.

2nd, the energy conversion efficiency between different gears differs greatly.Because China is industrial, civilian power supply is to determine frequency 50Hz, is operated under the gear of different rotating speeds in motor, and the operating point of only indivedual gears reaches higher energy conversion efficiency, The efficiency of remaining gear will be greatly reduced.

3rd, when actual speed and synchronous rotational speed differ greatly, the mechanical features of motor output is softer, what rotating speed was loaded Influence is big.

Variable frequency drives are used in industry, the AC power that frequency is fixed into 50Hz is transformed to the polyphase ac of frequency-adjustable Power supply, solves above-mentioned defect.But increase variable frequency drives, will substantially show the cost of increase system.Wherein electronic power switch It is the pith for constituting variable frequency drives cost.

Row alternating-current variable frequency motor commonly used in the trade, mostly using three phase electric machine, compared to monophase machine, its winding wire winding Relatively complicated, the teeth groove number of stator core is more, and manufacturing cost is high, and drives the electronic power needed for three phase alternating current motor The quantity of switch is 6 (such as Fig. 1 and Fig. 2).

The wire winding of load motor is relatively simple, but its demand to electronic power switch is more, by normal Rule method needs 8 electronic power switch（Such as Fig. 3）, electronics more more than 6 electronic power switch needed for three phase alternating current motor The utilization rate of power switch is low, cost increase, thus is seldom used in industry.

The another way (such as Fig. 4) of electronic power switch is reduced, frequency-variable controller only exports sinusoidal drive signals all the way, One phase winding of motor, and another phase winding is in the conventional mode, series connection shift capacitor with obtain it is shifted after drive Streaming current.Although this mode can reduce the electronic power switch consumption of half, the angle and driving frequency of electric capacity phase shift Directly related, motor can be only formed close to round rotating excitation field in narrower rotating speed and load setting, if off-target work Make a little, rotating excitation field will be changed into ellipse, the performance of motor will decline to a great extent.

Therefore, those skilled in the art is directed to developing a kind of single-phase motor variable frequency drive.

Utility model content

In view of the drawbacks described above of prior art, technical problem to be solved in the utility model is to provide a kind of single-phase electricity Motivation variable frequency drive, using variable frequency drives, using load motor, to simplify manufacturing process, uses novel electricity Line structure form, a fairly large number of deficiency of electronic power switch needed for both having solved conventional ADS driving mode, also solves motor efficient The narrow deficiency of the operation interval of operation.

To achieve the above object, the utility model provides a kind of single-phase motor variable frequency drive, including the first electricity Sub- power switch, the second electronic power switch, the 3rd electronic power switch, the 4th electronic power switch, electric capacity and motor, the One electronic power switch, the second electronic power switch constitute a half-bridge, are connected with the winding U of motor, the 3rd electronic power is opened Close, the 4th electronic power switch constitutes a half-bridge, be connected with the winding V of motor.The winding common port of U, V two and electric capacity of motor Positive pole is connected, and electric capacity negative pole connects power cathode.

Preferably, described motor is the single-phase asynchronous motor with two orthogonal windings.

Preferably, described electric capacity is energy storage and capacitance.

Preferably, described electric capacity one end is connected with the common port of motor, the other end is connected with power supply.

Preferably, the first described electronic power switch SW1, the second electronic power switch, the 3rd electronic power switch, 4th electronic power switch is insulating gate type field effect tube, insulated gate bipolar transistor or double pole triode.

The beneficial effects of the utility model are：

1st, using the energy storage of electric capacity, and the feature that the circulation of electric capacity blocking is exchanged, what half-bridge was exported includes flip-flop Pwm signal be filtered, block the flip-flop in drive signal, it is to avoid therefore cause machine winding seriously to generate heat.It is another Aspect, machine winding is coupled to the alternating component in output pwm signal, machine winding is obtained appropriate drive signal.

2nd, only increase a capacitor, make to reduce by four electronic power switch devices in conventional drive circuit scheme, from And the cost of drive circuit is substantially reduced, simplify drive circuit, while excellent performance can be obtained.

The technique effect of design of the present utility model, concrete structure and generation is made furtherly below with reference to accompanying drawing It is bright, to be fully understood from the purpose of this utility model, feature and effect.

Brief description of the drawings

Fig. 1 is traditional alternating-current variable frequency power drive circuit figure in background technology of the present utility model；

Fig. 2 is another alternating-current variable frequency power drive circuit figure in background technology of the present utility model；

Fig. 3 is the drive circuit figure of the load motor in background technology of the present utility model；

Fig. 4 is the drive circuit figure of another load motor in background technology of the present utility model；

Fig. 5 is single-phase motor variable frequency drive of the present utility model；

Fig. 6 is load motor frequency changing driving system schematic diagram of the present utility model.

Embodiment

As seen in figs. 5-6, a specific embodiment of the present utility model, a kind of single-phase motor variable frequency drive, including First electronic power switch SW1, the second electronic power switch SW2, the 3rd electronic power switch SW3, the 4th electronic power switch SW4, electric capacity C and motor MOTOR, the first electronic power switch SW1, the second electronic power switch SW2 constitute a half-bridge, and It is connected with motor MOTOR winding U, the 3rd electronic power switch SW3, the 4th electronic power switch SW4 constitute a half-bridge, and It is connected with motor MOTOR winding V, motor MOTOR winding U phases, the common port of winding V phases are connected with electric capacity C positive poles, electric capacity C negative poles connect power cathode.

It is worth noting that, described motor MOTOR is the single-phase asynchronous motor with two orthogonal windings.

It is worth noting that, described electric capacity C is energy storage and capacitance.

It is worth noting that, described electric capacity C one end is connected with motor MOTOR common port, the other end is connected with power supply.

In addition, the first described electronic power switch SW1, the second electronic power switch SW2, the 3rd electronic power switch SW3, the 4th electronic power switch SW4 are insulating gate type field effect tube MOSFET, insulated gate bipolar transistor IGBT or double Polar form triode BJT.

The operation principle of present embodiment：First electronic power switch SW1 and the second electronic power switch SW2 is constituted One half-bridge, the 3rd electronic power switch SW3 and the 4th electronic power switch SW4 constitute another half-bridge, and unit is driven respectively The winding of the U of asynchronous machine, V two.Due to half-bridge export pwm signal relative to ground reference be unipolarity, flow through winding Electric current always same direction, it is impossible to apply the alternating current that direction is alternately opposite to winding, need to additionally increase by traditional method One half-bridge constitutes full-bridge, to realize that electric current commutation is acted on, so as to cause number of devices many, cost is high.Present embodiment Middle setting output capacitor, is connected on ground wire after being connected with machine winding, when half-bridge upper arm SW1 is turned on, source current From upper arm, ground wire is flowed to UB ends, then through electric capacity C by winding U UA ends, while electric capacity C is electrically charged；When upper arm SW1 cut-offs And during underarm SW2 conductings, the electric energy stored by electric capacity C flows through underarm SW2 from winding U UB ends to UA ends, then is back to electric capacity C negative poles, form reverse current loop.Similarly, motor V phase windings are driven by SW3, SW4 alternate conduction, also can obtain direction Different alternating currents.

As practical plan, the utility model coordinates following traditional circuit to constitute complete variable frequency drives.

The rectified bridge B1 rectifications of AC power and electric capacity C1 filtering, obtain relatively stable DC bus-bar voltage+310V, carry For the power supply needed for half-bridge circuit.

DC bus-bar voltage+310V is changed through DC-DC module transformation, and obtaining+15V voltages, there is provided pre-driver chip U4 With the power supply needed for U5.

The linear voltage-stablizer U3 decompressions of+15V voltages, are obtained to stable+3.3V voltages, supply control chip U1 and its periphery Associated member.

Control chip U1 is used to produce the orthogonal SPWM signals of two-way, and control, the operation for coordinating whole frequency changer circuit.

After the orthogonal SPWM signals amplification that pre-driver chip U4, U5 produces U1, drive described in the utility model Variable frequency drive.

Preferably, the present embodiment selects IGBT as electronic power switch, can also according to different use demands From MOSFET, BJT or IPM modules make electronic power switch.

To realize more perfect function, the present embodiment is provided with current sense resistor RS, detects bus current, is sent to control Coremaking piece U1 makees overcurrent protection and operation control is used.

To realize more perfect function, the present embodiment is provided with busbar voltage detection device, after resistance R1, R2, R3 partial pressure Control chip U1 work overvoltages detection, under-voltage detection and operation control is sent to use.

To realize more perfect function, the present embodiment is provided with PORT COM CN1, inputs and transports as external control signal The effect of row state output.

Preferred embodiment of the present utility model described in detail above.It should be appreciated that the ordinary skill people of this area Member just can make many modifications and variations without creative work according to design of the present utility model.Therefore, all this technology necks Technical staff passes through logic analysis, reasoning or limited reality on the basis of existing technology according to design of the present utility model in domain Available technical scheme is tested, all should be in the protection domain being defined in the patent claims.

Claims

1. a kind of single-phase motor variable frequency drive；It is characterized in that：Including the first electronic power switch (SW1), the second electricity Sub- power switch (SW2), the 3rd electronic power switch (SW3), the 4th electronic power switch (SW4), electric capacity (C) and motor (MOTOR), the first electronic power switch (SW1), the second electronic power switch (SW2) constitute a half-bridge, and and motor (MOTOR) winding U is connected, and the 3rd electronic power switch (SW3), the 4th electronic power switch (SW4) constitute a half-bridge, and It is connected with the winding V of motor (MOTOR), winding U phases, the common port of winding V phases and electric capacity (C) the positive pole phase of motor (MOTOR) Even, electric capacity (C) negative pole connects power cathode.

2. a kind of single-phase motor variable frequency drive according to claim 1；It is characterized in that：Described motor (MOTOR) it is the single-phase asynchronous motor with two orthogonal windings.

3. a kind of single-phase motor variable frequency drive according to claim 1；It is characterized in that：Described electric capacity (C) For energy storage and capacitance.

4. a kind of single-phase motor variable frequency drive according to claim 1；It is characterized in that：Described electric capacity (C) One end is connected with the common port of motor (MOTOR), and the other end is connected with power supply.

5. a kind of single-phase motor variable frequency drive according to claim 1；It is characterized in that：The first described electronics Power switch (SW1), the second electronic power switch (SW2), the 3rd electronic power switch (SW3), the 4th electronic power switch (SW4) it is insulating gate type field effect tube (MOSFET), insulated gate bipolar transistor (IGBT) or double pole triode (BJT)。