CN200990583Y

CN200990583Y - AC electric machine intelligent electricity economizer

Info

Publication number: CN200990583Y
Application number: CN 200620148795
Authority: CN
Inventors: 应章强
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-25
Filing date: 2006-10-18
Publication date: 2007-12-12
Anticipated expiration: 2016-10-18

Abstract

The utility model relates to an energy saving system of electromotor, which comprises an electromotor start circuit, a phase shift triggering circuit, a six way dipulse forming circuit, a trigger pulse magnifying and separating circuit, a thriphase half control bridge type voltage regulating output circuit, an electromotor voltage sampling circuit, an electromotor electric current sampling circuit, a move phase control voltage form circuit, a ring shaped oscillator, a triphase commute transformer and a synchronous transformer circuit and a triphase synchronous voltage form circuit. When using the electrical appliance, the triphase angle of flow neat degree is high, regimen is well, spark is steady and reliable. The spark current is big. The move phase range is wide. The power save effect is obvious. The saving rate is 12 percent to 60 percent. The electrical appliance has strong applicability for the environment temperature and low cost, can reduce the electric appliance emit heat, prolong the service life, can withdraw cost by saving electric power change in short time, is specially suitable for electromotor saving electricity with middle and light load works.

Description

Intelligent powersaving device for AC motor

Technical field

The utility model relates to a kind of motor energy saving devices, be specially adapted in, the battery saving arrangement of the motor of working under the underload.

Background technology

The exploitation of the energy and control are global problems, and it is directly connected to human existence and development, do not have which country not at the effective scheme of doing all one can to seek to solve energy problem.The reserves of fossil energy are limited, and the emphasis that solves energy problem has just been fallen on the new energy development and the existing energy energy-conservation naturally.Electric energy is one of most widely used energy, also is most important component in the energy resource consumption, and economize on electricity is energy-conservation major subjects.

General alternating current motor, it is the power-equipment that the prevailing electric energy in the world converts mechanical energy to, show according to relevant authoritative institution data, in the various generating equipment generating total amounts, about 70% is to consume on motor, the motor of an operate as normal consumed 20 times the electricity charge of its self-value in 1 year unexpectedly.China is an energy shortage and the huge country of consuming energy, and energy saving motor all is a very important and useful thing for country, enterprise even individual.

Be born till now from motor, the phenomenon of " low load with strong power " is very general, the reason that causes has two, the one, when the buying type selecting, the motor that the technical staff chose, its power choosing value generally all is higher than actual peak load, the 2nd, the injection molding machine of each model, oil-field oil pumper, automatic elevator, air compressor, and car, cut, dig, motor on the equipment such as milling machine tool, the real work load all changes, the motor capacity of being matched all designs by maximum load, and in the reality motor major part in, work under the light load, so just wasted a large amount of electric energy in vain.

Adopting the capacitance compensation energy saver, is to increase capacitor on change, controller switching equipment, thereby increases the power factor of supply network, reduces reactive loss, but the cost height, volume is big, and invalid to improving the power of electric motor factor.

Adopting the variable-frequency speed-adjusting energy-saving device is by changing electric voltage frequency, the realization motor speed adjusting is energy-conservation, but a lot of situation motor does not allow the common price of variable-speed operation, particularly frequency converter very expensive, and to some requirement for restriction on the electric motor structure, this has just limited the range of application of energy-saving and frequency-variable.

Adopt the bidirectional triode thyristor control angle of flow; realize the terminal voltage of motor step-less adjustment; thereby reduce the reactive loss of motor; reach the purpose of economize on electricity; method is simple; cost is low; but ubiquity detection and control circuit adopt a large amount of discrete components in prior art and the product; electric moter voltage/current sampling circuit is vulnerable to the interference of electromagnetic field; poor stability, failure rate height, power saving rate are not high; can not switch after breaking down, dally over one's work and can not show energy-saving effect and great power bidirectional controllable silicon price height; the bad job stability that influences dispels the heat; problems such as motor protection is not good enough.The utility model of China Patent No. 02250736 " threephase motor electricity-saving appliance " adopts a large amount of discrete components, just has the problems referred to above.

The utility model content

The purpose of this utility model is the defective that exists at above-mentioned prior art, provides a kind of strong interference immunity, job stability height, failure rate is low, cost is low, the tangible energy saving motor protective device of energy-saving effect.

For achieving the above object, the utility model is realized by the following technical solutions: electricity-saving appliance of the present utility model comprises cabinet, cooling fan, power supply; Cooling fan and power supply are arranged in the cabinet; Its design feature is: three-phase power input end A, B, the C that can be connected with three-phase alternating-current supply when also comprising the use that is arranged on the cabinet; Comprise that also the electric motor starting circuit, phase-shift trigger circuit, six tunnel dipulses that are arranged in the cabinet form circuit, trigger impulse power amplification and buffer circuit, three-phase half controlled bridge formula pressure regulation output circuit, electric moter voltage sample circuit, current of electric sample circuit, current transformer TA1, phase shift controlling voltage and form hold concurrently synchrotrans circuit and three-phase synchronizing voltage of circuit, ring oscillator, three-phase rectifier transformer and form circuit; Wherein the electric motor starting circuit has main control loop and controlled device; The main control loop of electric motor starting circuit is connected between the two ends of three-phase power input end A, B, C; The hold concurrently input of synchrotrans circuit of three-phase rectifier transformer is connected with three-phase power input end A, B, C; The three-phase rectifier transformer three-phase ac signal input that three-phase ac signal output and the three-phase synchronizing voltage of synchrotrans circuit form circuit of holding concurrently is connected; The three-phase synchronous voltage signal output that the three-phase synchronizing voltage forms circuit is connected with the synchronous signal input end of phase-shift trigger circuit; The pulse output end of phase-shift trigger circuit is connected with the pulse input end that six tunnel dipulses form circuit; The trigger impulse output that six tunnel dipulses form circuit is connected with the trigger impulse input of trigger impulse power amplification and buffer circuit; The trigger impulse output of trigger impulse power amplification and buffer circuit is connected with the trigger impulse input of three-phase half controlled bridge formula pressure regulation output circuit; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, c link to each other with one group of three-phase link of the controlled device of electric motor starting circuit; The port that another group three-phase link of the controlled device of electric motor starting circuit can be connected with the three-phase input end of alternating current machine when being to use; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, c also are connected with the input of electric moter voltage sample circuit; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, the phase among the c are connected with the input of current of electric sample circuit by current transformer TA1; The output of electric moter voltage sample circuit is connected with the respective input mouth that phase shift controlling voltage forms circuit; The output of current of electric sample circuit is connected with the respective input mouth that phase shift controlling voltage forms circuit; The phase shift controlling voltage signal output part that phase shift controlling voltage forms circuit is connected with phase-shift trigger circuit phase-shifting voltages input; The oscillator signal output of ring oscillator is connected with the input of phase-shift trigger circuit; The hold concurrently rectification output end of synchrotrans circuit of three-phase rectifier transformer is connected with the power supply input; The power output end of power supply is connected with the power end of phase-shift trigger circuit, six tunnel dipulses formation circuit, trigger impulse power amplification and buffer circuit, phase shift controlling voltage formation circuit, ring oscillator respectively.

Electricity-saving appliance of the present utility model can also comprise alternating current watch circuit and the alternating voltage watch circuit on the three-phase output end of the three-phase half controlled bridge formula that the is arranged on pressure regulation output circuit that is used to monitor the motor load state; The alternating current watch circuit is made up of the D.C mutual-inductor TA2 of 1 to 3 alternating current ammeter and respective numbers; The alternating voltage watch circuit is made up of 1 to 3 A.C. voltmeter.

Electricity-saving appliance of the present utility model can also comprise an auxiliary functional circuit, and it is made up of the energy-conservation bypass change over switch of often opening, first A.C. contactor, economize on electricity indicator light and bypass indicator light; Energy-conservation bypass change over switch is connected with the coil KM1 of first A.C. contactor and is constituted control loop, and this control loop is arranged between the two ends of three-phase power input end A, B, C; One group of normally closed contact KM1-1 of first A.C. contactor is arranged on three-phase power input end A, B, C and three-phase rectifier transformer and holds concurrently between the input of synchrotrans circuit, one group of normally open contact KM1-2 of first A.C. contactor is arranged between three-phase output end a, b, the c of three-phase power input end and three-phase half controlled bridge formula pressure regulation output circuit, just can be switching to the bypass operating state just in case break down, not influence work; A normal opened contact among another group auxiliary contact KM1-3 of first A.C. contactor is connected with the bypass indicator light, this series circuit is in parallel with control loop, and a normally closed contact among this group auxiliary contact KM1-3 of first A.C. contactor is connected with the economize on electricity indicator light, this series circuit is also in parallel with control loop.

Above-mentioned phase-shift trigger circuit has three thyristor phase-shift trigger ics, comprises that model is the thyristor phase-shift trigger ic of TCA785.It is that model is six tunnel dipulses formation integrated circuit of KC41 that described six tunnel dipulses form circuit.Described trigger impulse power amplification and buffer circuit have three BU406 transistors and three pulse isolation transformers.Ring oscillator is that to have model be that the integrated circuit of DC4011 is at interior annular oscillation circuit.It is that to have model be that the integrated circuit of LM339 forms circuit at interior three-phase synchronizing voltage that described three-phase synchronizing voltage forms circuit.It is to have operational amplifier LM741 at interior electric moter voltage and current signal stack summation operation circuit that described phase shift controlling voltage forms circuit.Described electric moter voltage sample circuit has three-phase rectifier transformer, full-wave rectifying circuit and capacitance-resistance filter circuit, and full-wave rectifying circuit is made up of six rectifier diodes; Three inputs of three-phase rectifier transformer are the input of electric moter voltage sample circuit.

Above-mentioned current of electric sample circuit has transformer T3, full-wave rectifying circuit, capacitance-resistance filter circuit, sensitivity regulator potentiometer and triode amplifier, and full-wave rectifying circuit has two rectifier diodes; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, the phase end line among the c pass current transformer TA1, the output of current transformer TA1 is connected with the input of transformer T3, the output of transformer T3 is connected with two rectifier diodes of full-wave rectifying circuit, the output of full-wave rectifying circuit is connected with sensitivity regulator potentiometer W50 by the capacitance-resistance filter circuit, the center of sensitivity regulator potentiometer W50 is connected with the base stage of triode amplifier GB50, and sensitivity regulator potentiometer W50 is used for manual adjustment output voltage size.

Above-mentioned three-phase half controlled bridge formula pressure regulation output circuit has three electronic power switch devices and three rectifier diodes; The electronic power switch device is half control type device or full-control type device; Half control type device comprises the derivation device of thyristor and thyristor (SCR), and high speed thyristor, reverse conducting triode thyristor, bidirectional thyristor, asymmetrical triode thyristor are wherein arranged; Full-control type device controllable silicon comprises turn-off thyristor (GTO), power transistor (GTR or BJT), electric power field transistor (being power MOSFET), insulated gate bipolar transistor (IGT or IGBT), static induction transistor (SIT) and static induction thyristor (SITH); Cooling fan is installed in three-phase half controlled bridge formula pressure regulation output circuit next door.

Electricity-saving appliance of the present utility model also can have the full guard motor circuit; The main control loop of electric motor starting circuit is made of the coil KM2 series connection of shutdown switch, starting switch and second A.C. contactor; The main control loop of electric motor starting circuit is arranged between the two ends of three-phase power input end A, B, C; The controlled device of electric motor starting circuit is one group of normally open contact KM2-1 of second A.C. contactor, their end separately links to each other with three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, the corresponding end of c, and the normally open contact KM2-1 other end separately of second A.C. contactor is the port that can link to each other with a corresponding end of the three-phase input end of alternating current machine in use; The electric motor starting circuit also has the self-locking contact KM2-2 of second A.C. contactor; Full guard electric electromechanics route thermistor, first OR circuit and first relay circuit are formed; Described thermistor is the PTC thermistor; First OR circuit is three input transistors OR circuit; The output of thermistor connects the input of first OR circuit, and the output of first OR circuit links to each other with the control end of first relay circuit; First relay circuit is provided with the first relay coil J1, and the self-locking contact KM2-2 of second A.C. contactor of the first relay contact J1-1 and electric motor starting circuit is cascaded, and is connected in parallel on the two ends of the starting switch of electric motor starting circuit; Thermistor is imbedded the winding of alternating current machine or is installed in the contacted position of electronic power switch device with three-phase half controlled bridge formula pressure regulation output circuit.

Electricity-saving appliance of the present utility model can comprise that also line current detects open-phase protection circuit; The main control loop of electric motor starting circuit is made of the coil KM2 series connection of shutdown switch, starting switch and second A.C. contactor; The main control loop of electric motor starting circuit is arranged between the two ends of three-phase power input end A, B, C; The controlled device of electric motor starting circuit is one group of normally open contact KM2-1 of second A.C. contactor, their end separately links to each other with three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit, the corresponding end of c, and the normally open contact KM2-1 other end separately of second A.C. contactor is the port that can link to each other with a corresponding end of the three-phase input end of alternating current machine in use; The electric motor starting circuit also has the self-locking contact KM2-2 of second A.C. contactor; Line current detects open-phase protection circuit and is made up of current transformer, photoelectricity coupling circuit, second OR circuit, delayer and second relay circuit; The coil of current transformer is arranged on three-phase output end a, b, the c of three-phase half controlled bridge formula pressure regulation output circuit, the output of each current transformer links to each other with the input of the corresponding photocoupler of photoelectricity coupling circuit, the output of photoelectricity coupling circuit connects the input of second OR circuit, the output of second OR circuit links to each other with the input of delayer, and the output of delayer links to each other with the control end of second relay circuit; Second relay circuit is provided with the second relay coil J2, and the self-locking contact KM2-2 of second A.C. contactor of the second relay contact J2-1 and electric motor starting circuit is cascaded, and is connected in parallel on the two ends of the starting switch of electric motor starting circuit.

The exportable 380V of interchange in the time of can being to use with the port that the three-phase input end of alternating current machine is connected during the use of the controlled device of above-mentioned start-up circuit, exchange 660V or exchange the port of 1140V.Also be that the utility model can use on the motor that exchanges 380V, 660V, 1140V.

Compared with prior art, the utlity model has following clear superiority: electricity-saving appliance 1. of the present utility model can be linked to each other with the terminals of alternating current machine by its electric motor starting circuit before use.Because the utility model adopted the Thyristor Special phase-shift trigger ic, thus trigger reliable and stable, the neat degree height of the three-phase angle of flow, trigger current is big, applicable heavy-duty motor, phase shift range is wide, can be according to payload, automatically regulate the angle of flow, power savings is remarkable, and the saving rate is minimum to be 12%, reaches as high as 60%, strong to environmental adaptability, thus reliably working guaranteed.2. after the utility model was used to control alternating current machine, owing to be in the step-down user mode, so starting current reduces, heating reduced when motor used, thereby increased the service life.3. after the utility model is provided with auxiliary functional circuit,, switch to the bypass operating state, also can not influence production just in case break down then increased fail-over feature.4. after the utility model was provided for monitoring the alternating voltage watch circuit and alternating current watch circuit of motor load state, A.C. voltmeter wherein and alternating current ammeter can be used as energy-conservation demonstration, can also double as be operating condition monitoring.5. electricity-saving appliance of the present utility model is with low cost, and investor (3-8 month) in a short time passes through to economize the electricity charge, cost-recovering.6. after the utility model is provided with line current detection open-phase protection circuit; electricity-saving appliance then of the present utility model in use has line current and detects the open-phase protection function; detect phase failure signal by current transformer, photoelectricity resistance type photocoupler, delayer, OR circuit and relay circuit and directly promote the actuating of relay; carry out the phase failure and protect, circuit is novel reliable.7. after the utility model is provided with the full guard motor circuit; electricity-saving appliance then of the present utility model in use has the full guard motor function; adopt thermistor directly to monitor motor temperature protection motor;, ventilate fault such as be obstructed too high to motor gambling commentaries on classics, overload, the phase failure, Fraquent start, under-voltage operation, ambient temperature all shield.

Description of drawings

Fig. 1 is a kind of circuit block diagram of the present utility model;

Fig. 2 is an another kind of circuit block diagram of the present utility model;

Fig. 3 is that the utility model phase-shift trigger circuit, six tunnel dipulses form circuit, trigger impulse power amplification and buffer circuit, phase shift controlling voltage and form hold concurrently synchrotrans circuit, three-phase synchronizing voltage of circuit, ring oscillator, three-phase rectifier transformer and form the circuit theory diagrams of circuit and power supply;

Fig. 4 is the electrical schematic diagram of the utility model electric moter voltage sample circuit;

Fig. 5 is the electrical schematic diagram of the utility model current of electric sample circuit;

Fig. 6 is the electrical schematic diagram that three-phase half controlled bridge formula pressure regulation output circuit of the present utility model, line current detect open-phase protection circuit, full guard motor circuit and electric motor starting circuit.

What the label among the figure was represented thes contents are as follows: the 1-phase-shift trigger circuit; 2 six tunnel dipulses form circuit; power amplification of 3-trigger impulse and buffer circuit; 4-three-phase half controlled bridge formula pressure regulation output circuit; 6-electric moter voltage sample circuit; 7-current of electric sample circuit; the 8-phase shift controlling voltage forms circuit; the 9-ring oscillator; the 10-three-phase rectifier transformer synchrotrans circuit of holding concurrently; 11-three-phase synchronizing voltage forms circuit; the 12-power supply; 13-alternating current watch circuit; 14-alternating voltage watch circuit; the 15-auxiliary functional circuit; the 17-line current detects open-phase protection circuit and (contains 17-1; current transformer; 17-2; the photoelectricity coupling circuit; 17-3; second OR circuit; 17-4; delayer; 17-5; second relay circuit); 18-full guard motor circuit (contains 18-1; thermistor; 18-2; first OR circuit; 18-3; first relay circuit), 100-electric motor starting circuit.

Embodiment

Be elaborated with reference to accompanying drawing below in conjunction with embodiment, so that to the purpose of this utility model, feature and advantage are carried out more deep understanding.

See Fig. 1 and Fig. 2, the intelligent powersaving device for AC motor of present embodiment, three-phase power input end A, the B, the C that comprise cabinet, cooling fan, power supply 12 and can be connected with three-phase alternating-current supply when using.Cooling fan and power supply 12 are arranged in the cabinet; Three-phase power input end A, B, C that three-phase alternating-current supply is connected are arranged on the cabinet.

The intelligent powersaving device for AC motor of present embodiment also comprises the electric motor starting circuit 100 that is arranged in the cabinet, phase-shift trigger circuit 1, six tunnel dipulses form circuit 2, trigger impulse power amplification and buffer circuit 3, three-phase half controlled bridge formula pressure regulation output circuit 4, electric moter voltage sample circuit 6, current of electric sample circuit 7, current transformer TA1, phase shift controlling voltage forms circuit 8, ring oscillator 9, the three-phase rectifier transformer synchrotrans circuit 10 of holding concurrently, form circuit 11 with the three-phase synchronizing voltage.

Above-mentioned electric motor starting circuit 100 has main control loop and controlled device; The main control loop of electric motor starting circuit 100 is connected between the two ends of three-phase power input end A, B, C; The hold concurrently input of synchrotrans circuit 10 of three-phase rectifier transformer is connected with three-phase power input end A, B, C.The three-phase rectifier transformer three-phase ac signal input that three-phase ac signal output and the three-phase synchronizing voltage of synchrotrans circuit 10 form circuit 11 of holding concurrently is connected.The three-phase synchronous voltage signal output that the three-phase synchronizing voltage forms circuit 11 is connected with the synchronous signal input end of phase-shift trigger circuit 1.The pulse output end of phase-shift trigger circuit 1 is connected with the pulse input end that six tunnel dipulses form circuit 2.The trigger impulse output that six tunnel dipulses form circuit 2 is connected with the trigger impulse input of trigger impulse power amplification and buffer circuit 3.The trigger impulse output of trigger impulse power amplification and buffer circuit 3 is connected with the trigger impulse input of three-phase half controlled bridge formula pressure regulation output circuit 4.Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, c link to each other with one group of three-phase link of the controlled device of electric motor starting circuit 100; The port that another group three-phase link of the controlled device of electric motor starting circuit 100 can be connected with the three-phase input end of alternating current machine 5 when being to use.Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, c also are connected with the input of electric moter voltage sample circuit 6; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, the phase among the c by current transformer TA1, are connected with the input of current of electric sample circuit 7.The output of electric moter voltage sample circuit 6 is connected with the respective input mouth that phase shift controlling voltage forms circuit 8.The output of current of electric sample circuit 7 is connected with the respective input mouth that phase shift controlling voltage forms circuit 8; The phase shift controlling voltage signal output part that phase shift controlling voltage forms circuit 8 is connected with phase-shift trigger circuit 1 phase-shifting voltages input.The oscillator signal output of ring oscillator 9 is connected with the input of phase-shift trigger circuit 1.The hold concurrently rectification output end of synchrotrans circuit 10 of three-phase rectifier transformer is connected with power supply 12 inputs.The power output end of power supply 12 is connected with the power end of phase-shift trigger circuit 1, six tunnel dipulses formation circuit 2, trigger impulse power amplification and buffer circuit 3, phase shift controlling voltage formation circuit 8, ring oscillator 9 respectively.

As shown in Figure 3, civil power 380V three-phase alternating current A, B, C, be connected with three-phase rectifier transformer synchrotrans circuit 10 inputs of holding concurrently, output divides a two-way, the rectification of the full-wave rectifying circuit that the three-phase rectifier transformer BT1 of leading up to and six rectifier diode D1～D6 form, through capacitance-resistance filter, more respectively through three-terminal voltage-stabilizing circuit VM7815 and LM7915 generation+15V and-15V makes power supply.Another road is by synchrotrans BT1, send into the three-phase synchronizing voltage and form circuit 11, behind capacitance-resistance filter, voltage comparator through LM339 and additional device composition, detect the zero passage synchronizing signal, send into the 5th pin synchronizing voltage input of each thyristor phase-shift trigger ic TCA785 of phase-shift trigger circuit 1.Phase-shift trigger circuit 1 is made up of three TCA785 thyristor phase-shift trigger ics and corresponding auxiliary circuit, TCA785 is the outstanding phase shifting control chip of a kind of performance that Siemens is produced, and this device can be widely used in the thyristor control system.The inside of TCA785 by zero point discriminator ZD, SYN register SR, constant-current source SC, control comparator CC, discharge transistor V, discharge watch-dog DM, level conversion and 9 unit such as voltage stabilizing circuit PC, saw-toothed wave generator RG and output logic network LN form.It is wide that this device has temperature accommodation, advantages such as the identification to zero crossing is more reliable, and the regularity of output pulse is better, and phase shift range is wideer, can discern the zero crossing of synchronous AC power supply reliably, thereby can constitute Zero-point switch as zero cross fired easily; Its input, output and CMOS and Transistor-Transistor Logic level compatibility have the applied voltage scope of broad and bigger load driving ability, and the drive current of 250mA can be directly exported on every road; Its circuit structure has determined wider range of self sawtooth voltage, and is stronger to the adaptability of ambient temperature, can be applicable to the ambient temperature range (TA=-25～+ 85 ℃) of broad and working power voltage scope (0.5～+ 18V).

Ring oscillator 9 is made up of DC4011, forms the separated exciting ring oscillator by four the 2 input nand gate circuit of DC4011, and its output is connected with 7 pin of TCA7856, pulse is become pulse train, frequency 5-10HZ.

Six tunnel dipulses form circuit 2 to be made up of KC41C, and KC41C has that dipulse forms and electronic switch control is blocked dipulse and formed two kinds of functions, and the basic pulse to 14,15 pin of TCA785 are exported dashes by input diode generation supplements.

The trigger impulse power amplification is made up of three BC406 pliotrons, three pulse isolation transformers and relevant auxiliary element with buffer circuit 3, the trigger impulse of its output of KC41C is sent to the control utmost point of three thyristors again through the power amplification of BC406 triode through pulse isolating transformer T1, T2, T3.

As shown in Figure 6, three-phase half controlled bridge formula pressure regulation output circuit 4 is by three thyristor V1, V3, V5 and three half-controlled bridge type circuit that rectifier diode V2, V4, V6 form.The control utmost point of three thyristors is connected with the port of three respective pulses isolating transformer T1, T2, T3 respectively.Consider user's motor mostly be in, light load, so adopt the pressure regulation of three-phase half controlled bridge formula, only control the negative half period angle of flow, positive half cycle is not controlled.Can save like this and use expensive great power bidirectional triggering thyristor or save three high-power unidirectional triggering thyristors, substitute with common rectifying tube, both economize cost, the electric current that tube core is flow through reduces, thereby has improved thermal stability, makes reliable operation.

As shown in Figure 4, electric moter voltage sample circuit 6 has three-phase rectifier transformer T2, full-wave rectifying circuit and capacitance-resistance filter circuit, and full-wave rectifying circuit is made up of six rectifier diodes 4148; Three inputs of three-phase rectifier transformer T2 are connected with output a, b, the c of three-phase half controlled bridge formula pressure regulation output circuit 4.The loading resistor of three full-wave rectifying circuits is same R, and the electric moter voltage sampled value is the voltage on the R, and the signal of reflection electric moter voltage is from J-1, the output of J-2 guide line.

As shown in Figure 5, current of electric sample circuit 7 has transformer T3 full-wave rectifying circuit, capacitance-resistance filter circuit, sensitivity regulator potentiometer RT and triode amplifier 9012, and full-wave rectifying circuit has two rectifier diode D50, D51; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, the phase end line of c pass current transformer TAI, the output of current transformer TA1 is connected with the transformer T3 input of current of electric sample circuit 7, transformer T3 output is connected with the full-wave rectifying circuit of current of electric sample circuit 7, the output of full-wave rectifying circuit is connected with sensitivity regulator potentiometer W50 by the capacitance-resistance filter circuit, and the center of sensitivity regulator potentiometer W50 is connected with the base stage of triode amplifier GB50 by resistance R 55.The current of electric sampled value reflects that promptly the signal of current of electric is from J-3, the output of J-4 guide line.The course of work of full-wave rectifying circuit is: when the transformer T3 of current of electric sample circuit 7 secondary winding upper end is positive half period, electric current is from T3 secondary winding upper end, through resistance R 51, pass through potentiometer W50 again, pass through resistance R 54, R53 and rectifier diode D51 again, to T3 secondary winding lower end, finish once circulation; When transformer T3 secondary winding lower end was positive half period, electric current through resistance R 52, passed through potentiometer W50 from T3 secondary winding lower end again, passes through resistance R 54, R53 and rectifier diode D50 again, to T3 secondary winding upper end, finished once circulation.

See Fig. 2 to Fig. 6, the motor load of electric moter voltage sample circuit 6 and current of electric sample circuit 7 is measured and the three-phase half controlled bridge formula pressure regulation of three-phase half controlled bridge formula pressure regulation output circuit 4 is closed-loop systems, three-phase voltage a after the pressure regulation, b, c exports from J-3, J-4 guide line from J-1, the output of J-2 guide line and current of electric sample circuit 7 through electric moter voltage sample circuit 6.J-1, J-2, J-3, J-4 guide line are connected with the connector J that phase shift controlling voltage forms circuit 8.

The voltage/current signals of drawing by pin J-1, J-2, J-3, the J-4 of connector J, the operational amplifier LM741 that forms circuit 8 at phase shift controlling voltage makes summation operation, produce phase shift controlling voltage, send 11 pin of the TCA785 of phase-shift trigger circuit 1 to go to compare again with sawtooth waveforms.The W4 of phase-shift trigger circuit 1, W5, W6 are the variable resistance that 9 pin are drawn, and are used for regulating the slope of three-phase sawtooth waveforms.

Form circuit 3 by six tunnel dipulses, basic pulse to 14, the 15 pin output of the TCA785 of phase-shift trigger circuit 1, the generation supplements dashes, the trigger impulse of its output is through the power amplification of three BU406 triodes, be sent to G1, G3, G5 and K1, K3, the K5 utmost point of three thyristor V1, V3, V5 again through three pulse isolation transformer T1, T2, T3, so just realized that the electric current with alternating current machine 5 two ends, the variation of voltage control the angle of flow of thyristor, carried out the closed-loop control of alternating current machine automatically.

It is as follows to set forth the course of work with Fig. 6:

1. the energy-conservation bypass change over switch K1 by auxiliary functional circuit 15 selects working method: when selecting power save mode, the control coil KM1 of first A.C. contactor does not work, the economize on electricity indicator light is bright, and three-phase alternating current A, B, the C normally closed interlock KM1-1 by first A.C. contactor is added to three-phase rectifier transformer and holds concurrently on synchrotrans circuit 10 and the three half-controlled bridge type pressure regulation output circuits 4; When selecting bypass mode, the control coil KM1 energising work of first A.C. contactor, the bypass indicator light is bright, and three-phase alternating current A, B, C directly link to each other with three-phase output end a, b, the c three-phase of the three-phase half controlled bridge formula pressure regulation output circuit 4 that can connect alternating current machine 5 by the normally open contact KM1-2 of first A.C. contactor.

2. see Fig. 6, the electric motor starting circuit 100 of electricity-saving appliance of the present utility model adopts circuit commonly used.The main control loop of electric motor starting circuit 100 is made of the coil KM2 series connection of shutdown switch, starting switch and second A.C. contactor; The controlled device of electric motor starting circuit 100 is one group of normally open contact KM2-1 of second A.C. contactor; Electric motor starting circuit 100 also has the self-locking contact KM2-2 of second A.C. contactor, the normally closed interlock JI-1 of first relay and the normally closed interlock J2-1 of second relay.The main control loop of electric motor starting circuit 100 is arranged between the two ends of three-phase power input end A, B, C; The self-locking contact KM2-2 of second A.C. contactor, the normally closed interlock J1-1 of first relay and the normally closed interlock J2-1 of second relay are cascaded successively, and are connected in parallel on the two ends of starting switch; The normally open contact KM2-1 of second A.C. contactor is as the controlled device of electric motor starting circuit 100, their end separately links to each other with three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, the corresponding end of c, and the normally open contact KM2-1 other end separately of second A.C. contactor is the port that can link to each other with a corresponding end of the three-phase input end of alternating current machine 5 in use.

Press the starting switch among Fig. 6, the control coil KM2 of second A.C. contactor is got, carry out self-locking work by the normally closed interlock J1-1 of its self-locking contact KM2-2, first relay and the normally closed interlock J2-1 of second relay, the normally open contact KM2-1 adhesive of second A.C. contactor, three-phase alternating-current motor 5 gets electric work.

3. the full guard function of motor.See Fig. 6, full guard motor circuit 18 is made up of thermistor 18-1, the first OR circuit 18-2 and the first relay circuit 18-3; The described first OR circuit 18-2 is three input transistors OR circuit; The output of thermistor 18-1 connects the input of the first OR circuit 18-2, the output of the first OR circuit 18-2 with the control end of the first relay circuit 18-3, also be that the base stage of triode BG1 links to each other; The first relay circuit 18-3 is provided with the first relay coil J1.Thermistor 18-1 adopts the PTC thermistor of positive temperature coefficient.Thermistor 18-1 can be arranged on the winding of alternating current machine 5, also can be arranged on the contacted position of electronic power switch device of three-phase half controlled bridge formula pressure regulation output circuit 4, and the next door of this electronic switching device G1, G3, G5 is provided with fin contacted with it, thereby thermistor 18-1 can be arranged between electronic switching device G1, G3, G5 and the corresponding fin, so thermistor 18-1 is three.Because it is fast that the PTC thermistor has response speed; highly sensitive; volume is little; solid reliable; characteristics such as the life-span is long; it can directly react the temperature rise of alternating current machine 5; stall for alternating current machine 5; the phase failure; overload; Fraquent start; under-voltage operation; the ring temperature is too high; ventilation is obstructed etc. and is all shielded; when alternating current machine 5 temperature rises surpass " danger " point; the resistance cataclysm tens of thermistor is to hundred times; so the partial pressure value of they and resistance R 63～R65 changes; any one heating mutually; can make triode BG1 and triode BG2 conducting by the first OR circuit 18-2 that forms by resistance R 63～R65 and diode D61～D63; the coil J1 adhesive armature of first relay; thereby the contact J1-1 that causes being arranged in first relay of electric motor starting circuit 100 transfers disconnection to from normally closed; remove the self-locking state of the self-locking contact KM2-2 of second A.C. contactor; make the coil KM2 dead electricity of second A.C. contactor; and make the normally open contact KM2-1 of second A.C. contactor of second A.C. contactor transfer disconnection to by closure; thereby the cut-out three-phase alternating current is protected alternating current machine 5.

4. motor line current detecting phase failure protection function.Still see Fig. 6, line current detects open-phase protection circuit 17 and is made up of current transformer 17-1, photoelectricity coupling circuit 17-2, the second OR circuit 17-3, delayer 17-4 and the second relay circuit 17-5; Each coil of current transformer 17-1 is arranged on corresponding going up mutually of three-phase output end a, b, c of three-phase half controlled bridge formula pressure regulation output circuit 4, the output of each current transformer 17-1 links to each other with the input of the corresponding photocoupler of photoelectricity coupling circuit 17-2, the output of photoelectricity coupling circuit 17-2 connects the input of the second OR circuit 17-3, the output of the second OR circuit 17-3 links to each other with the input of delayer 17-4, the output of delayer 17-4 with the control end of the second relay circuit 17-5, also be that the base stage of triode BG3 links to each other; The second relay circuit 17-5 is provided with the second relay coil J2.The current transformer that is inserted on three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit 4, c is small current instrument transformer TA3, TA4 and TA5.During normal operation, the small current instrument transformer produces electric current, power supply at positive half cycle respectively through diode D65, D66, D67 rectification, to C63, C64, C65 charging and light light-emitting diode among photocoupler G1, G2, the G3, negative half period is lighted the light-emitting diode among G1, G2, the G3 by capacitor C 63, C64, C65 discharge, so the phototriode resistance of G1, G2, G3 is very low always because illumination is arranged; In case have one to disconnect mutually, electric current is 0, then the current transformer gone up mutually of this of Duan Kaiing does not just have electric current output, the phototriode resistance will be because of there not being illumination, and return to a very big resistance, as PTC thermistor above-mentioned, according to similar electric principle, the coil J2 adhesive armature that causes second relay, transfer disconnection even also be arranged in the contact J2-1 of second relay of electric motor starting circuit 100 to from normally closed, the same self-locking state of removing the self-locking contact KM2-2 of the second interchange contact, make the coil KM2 dead electricity of second A.C. contactor, and make the normally open contact KM2-1 of second A.C. contactor of second A.C. contactor transfer disconnection to by closure, thus cut off three-phase alternating current, alternating current machine 5 is protected; Wherein W60 and R77, C67 form delayer 17-4, in order to improve reliability and antijamming capability, avoid the conflict on the control timing.

In order to allow the user understand power savings, at AC voltage adjusting output a, b, c connects A.C. voltmeter, and connect alternating current ammeter by current transformer TA2, pass through formula: three-phase gross electric capacity W=3 * phase voltage V * phase current 1, allow alternating current machine 5 operate in power save mode and bypass condition respectively, just can calculate power savings.

For when contingency breaks down, do not influence and produce and work, be provided with energy-conservation bypass diverter switch K1, when needing energy-saving run, K switch 1 is in off-state, the economize on electricity indicator light is bright, A, B, C three-phase alternating current are successively by normally-closed contact KM1-1, the three-phase rectifier transformer of first A.C. contactor hold concurrently synchrotrans circuit 10 and three-phase half controlled bridge formula pressure regulation output circuit 4, be at electric motor starting circuit 100 under the situation of connection, to alternating current machine 5 power supplies; When breaking down, then with K switch 1 closure, the coil KM1 of first A.C. contactor gets electric and makes a normal opened contact closure among normally open contact KM1-2 and the contact KM1-3, normally closed interlock KM1-1 is disconnected, thereby make the bypass indicator light bright, cut off energy-conservation input, entire circuit is in by-path running status; A, B, C three-phase alternating current directly link to each other with three-phase output end a, b, the c of the three-phase half controlled bridge formula pressure regulation output circuit 4 that can connect alternating current machine 5 by the normally open contact KM1-2 of first A.C. contactor.

As modification of the present utility model, it is the energy-conservation of 660V or 1140V three-phase alternating-current motor that its principle also is adapted to electric pressure.

Below be the utility model electricity-saving appliance model machine in the pilot business situation of economizing on electricity.

Application examples 1, plastics industry

In the xx of changzhou company, be one of external coordination moulding enterprise of the whole province.The injection molding machine of existing 56 various models.The utility model electricity-saving appliance model machine of a 55KW is installed on the 16 hours production walkman box 50KW injection molding machines of working an every day, and the every monthly average of the utility model electricity-saving appliance model machine is obtained 16.5% power saving rate; Its reciprocation cycle is 6-12 month.

Application examples 2, petroleum industry

Place: Shengli Oil Field oil recovery factory, use equipment: 37KW plunger displacement pump (three-phase 37KW motor), application product: the utility model electricity-saving appliance model machine.

Before the installation: surveyed power consumption the same day: 266 degree;

The back is installed: surveyed power consumption the same day: 144.38 degree;

Effect: 1, power saving rate 43%; 2, improve production fluid amount 12%; 3, reduce the pump operation time 55%; 4, improve 2.2 times of pump efficiencys.

Application examples 3, quarry

Place: stone factory, Feng huangshan Mountain, use equipment: 150KW stone machine, application product: the utility model electricity-saving appliance model machine.

Before the installation: actual measurement power consumption 140-165K;

The back is installed: when actual measurement is unloaded, motor power consumption: 45KW;

This stone crusher was worked 16 hours every day, and under normal circumstances, after motor power consumption in every month 67424 degree (KWH) were installed the utility model electricity-saving appliance model machine, power consumption reduced to 8526 degree (KWH), and power saving rate was 12.6% in every month, and the period of investment return is 6-12 month.

Claims

1, a kind of intelligent powersaving device for AC motor comprises cabinet, cooling fan, power supply (12); Cooling fan and power supply (12) are arranged in the cabinet; It is characterized in that: three-phase power input end A, B, the C that can be connected with three-phase alternating-current supply when also comprising the use that is arranged on the cabinet; Also comprise the electric motor starting circuit (100) that is arranged in the cabinet, phase-shift trigger circuit (1), six tunnel dipulses form circuit (2), trigger impulse power amplification and buffer circuit (3), three-phase half controlled bridge formula pressure regulation output circuit (4), electric moter voltage sample circuit (6), current of electric sample circuit (7), current transformer TA1, phase shift controlling voltage forms circuit (8), ring oscillator (9), hold concurrently synchrotrans circuit (10) and three-phase synchronizing voltage of three-phase rectifier transformer forms circuit (11); Wherein electric motor starting circuit (100) has main control loop and controlled device; The main control loop of electric motor starting circuit (100) is connected between the two ends of three-phase power input end A, B, C; The hold concurrently input of synchrotrans circuit (10) of three-phase rectifier transformer is connected with three-phase power input end A, B, C; The three-phase rectifier transformer three-phase ac signal input that three-phase ac signal output and the three-phase synchronizing voltage of synchrotrans circuit (10) form circuit (11) of holding concurrently is connected; The three-phase synchronous voltage signal output that the three-phase synchronizing voltage forms circuit (11) is connected with the synchronous signal input end of phase-shift trigger circuit (1); The pulse output end of phase-shift trigger circuit (1) is connected with the pulse input end that six tunnel dipulses form circuit (2); The trigger impulse output that six tunnel dipulses form circuit (2) is connected with the trigger impulse input of trigger impulse power amplification with buffer circuit (3); The trigger impulse output of trigger impulse power amplification and buffer circuit (3) is connected with the trigger impulse input of three-phase half controlled bridge formula pressure regulation output circuit (4); Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), c link to each other with one group of three-phase link of the controlled device of electric motor starting circuit (100); The port that another group three-phase link of the controlled device of electric motor starting circuit (100) can be connected with the three-phase input end of alternating current machine (5) when being to use; Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), c also are connected with the input of electric moter voltage sample circuit (6); Three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), the phase among the c are connected with the input of current of electric sample circuit (7) by current transformer TA1; The output of electric moter voltage sample circuit (6) is connected with the respective input mouth that phase shift controlling voltage forms circuit (8); The output of current of electric sample circuit (7) is connected with the respective input mouth that phase shift controlling voltage forms circuit (8); The phase shift controlling voltage signal output part that phase shift controlling voltage forms circuit (8) is connected with phase-shift trigger circuit (1) phase-shifting voltages input; The oscillator signal output of ring oscillator (9) is connected with the input of phase-shift trigger circuit (1); The hold concurrently rectification output end of synchrotrans circuit (10) of three-phase rectifier transformer is connected with power supply (12) input; The power output end of power supply (12) is connected with the power end of phase-shift trigger circuit (1), six tunnel dipulses formation circuit (2), trigger impulse power amplification and buffer circuit (3), phase shift controlling voltage formation circuit (8), ring oscillator (9) respectively.

2, intelligent powersaving device for AC motor according to claim 1 is characterized in that: also comprise alternating current watch circuit (13) and alternating voltage watch circuit (14) on the three-phase output end of the three-phase half controlled bridge formula that the is arranged on pressure regulation output circuit (4) that is used to monitor the motor load state; The alternating current watch circuit is made up of the D.C mutual-inductor TA2 of 1 to 3 alternating current ammeter and respective numbers; The alternating voltage watch circuit is made up of 1 to 3 A.C. voltmeter.

3, intelligent powersaving device for AC motor according to claim 1 is characterized in that: also comprise an auxiliary functional circuit (15), it is made up of the energy-conservation bypass change over switch of often opening, first A.C. contactor, economize on electricity indicator light and bypass indicator light; Energy-conservation bypass change over switch is connected with the coil KM1 of first A.C. contactor and is constituted control loop, and this control loop is arranged between the two ends of three-phase power input end A, B, C; One group of normally closed contact KM1-1 of first A.C. contactor is arranged on three-phase power input end A, B, C and three-phase rectifier transformer and holds concurrently between the input of synchrotrans circuit (10), one group of normally open contact KM1-2 of first A.C. contactor is arranged between three-phase output end a, b, the c of three-phase power input end and three-phase half controlled bridge formula pressure regulation output circuit (4), just can be switching to the bypass operating state just in case break down, not influence work; A normal opened contact among another group auxiliary contact KM1-3 of first A.C. contactor is connected with the bypass indicator light, this series circuit is in parallel with control loop, and a normally closed contact among this group auxiliary contact KM1-3 of first A.C. contactor is connected with the economize on electricity indicator light, this series circuit is also in parallel with control loop.

4, intelligent powersaving device for AC motor according to claim 1 is characterized in that: described phase-shift trigger circuit (1) has three thyristor phase-shift trigger ics, comprises that model is the thyristor phase-shift trigger ic of TCA785.

5, intelligent powersaving device for AC motor according to claim 1 is characterized in that: it is that model is six tunnel dipulses formation integrated circuit of KC41 that described six tunnel dipulses form circuit (2); Described trigger impulse power amplification and buffer circuit (3) have three BU406 transistors and three pulse isolation transformers; Described ring oscillator (9) is that to have model be that the integrated circuit of DC4011 is at interior annular oscillation circuit; It is that to have model be that the integrated circuit of LM339 forms circuit at interior three-phase synchronizing voltage that described three-phase synchronizing voltage forms circuit (11); It is to have operational amplifier LM741 at interior electric moter voltage and current signal stack summation operation circuit that described phase shift controlling voltage forms circuit (8); Described electric moter voltage sample circuit (6) has three-phase rectifier transformer, full-wave rectifying circuit and capacitance-resistance filter circuit, and full-wave rectifying circuit is made up of six rectifier diodes; Three inputs of three-phase rectifier transformer are the input of electric moter voltage sample circuit (6).

6, intelligent powersaving device for AC motor according to claim 1, it is characterized in that: described current of electric sample circuit (7) has transformer T3, full-wave rectifying circuit, capacitance-resistance filter circuit, sensitivity regulator potentiometer and triode amplifier, and full-wave rectifying circuit has two rectifier diodes; Phase end line among three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), the c passes current transformer TA1, the output of current transformer TA1 is connected with the input of transformer T3, the output of transformer T3 is connected with two rectifier diodes of full-wave rectifying circuit, the output of full-wave rectifying circuit is connected with sensitivity regulator potentiometer W50 by the capacitance-resistance filter circuit, the center of sensitivity regulator potentiometer W50 is connected with the base stage of triode amplifier GB50, and sensitivity regulator potentiometer W50 is used for manual adjustment output voltage size.

7, intelligent powersaving device for AC motor according to claim 1 is characterized in that: described three-phase half controlled bridge formula pressure regulation output circuit (4) has three electronic power switch devices and three rectifier diodes; The electronic power switch device is half control type device or full-control type device; Half control type device comprises the derivation device of thyristor and thyristor (SCR), and high speed thyristor, reverse conducting triode thyristor, bidirectional thyristor, asymmetrical triode thyristor are wherein arranged; Full-control type device controllable silicon comprises turn-off thyristor (GTO), power transistor (GTR or BJT), electric power field transistor (being power MOSFET), insulated gate bipolar transistor (IGT or IGBT), static induction transistor (SIT) and static induction thyristor (SITH); Cooling fan is installed in three-phase half controlled bridge formula pressure regulation output circuit (4) next door.

8, intelligent powersaving device for AC motor according to claim 7 is characterized in that: also have full guard motor circuit (18); The main control loop of electric motor starting circuit (100) is made of the coil KM2 series connection of shutdown switch, starting switch and second A.C. contactor; The main control loop of electric motor starting circuit (100) is arranged between the two ends of three-phase power input end A, B, C; The controlled device of electric motor starting circuit (100) is one group of normally open contact KM2-1 of second A.C. contactor, their end separately links to each other with three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), the corresponding end of c, and the normally open contact KM2-1 other end separately of second A.C. contactor is the port that can link to each other with a corresponding end of the three-phase input end of alternating current machine (5) in use; Electric motor starting circuit (100) also has the self-locking contact KM2-2 of second A.C. contactor; Full guard motor circuit (18) is made up of thermistor (18-1), first OR circuit (18-2) and first relay circuit (18-3); Described thermistor (18-1) is the PTC thermistor; First OR circuit (18-2) is three input transistors OR circuit; The output of thermistor (18-1) connects the input of first OR circuit (18-2), and the output of first OR circuit (18-2) links to each other with the control end of first relay circuit (18-3); First relay circuit (18-3) is provided with the first relay coil J1, the self-locking contact KM2-2 of second A.C. contactor of the first relay contact J1-1 and electric motor starting circuit (100) is cascaded, and is connected in parallel on the two ends of the starting switch of electric motor starting circuit (100); Thermistor (18-1) is imbedded the winding of alternating current machine (5) or is installed in the contacted position of electronic power switch device with three-phase half controlled bridge formula pressure regulation output circuit (4).

9, according to the described intelligent powersaving device for AC motor of one of claim 1 to 8, it is characterized in that: comprise that also line current detects open-phase protection circuit (17); The main control loop of electric motor starting circuit (100) is made of the coil KM2 series connection of shutdown switch, starting switch and second A.C. contactor; The main control loop of electric motor starting circuit (100) is arranged between the two ends of three-phase power input end A, B, C; The controlled device of electric motor starting circuit (100) is one group of normally open contact KM2-1 of second A.C. contactor, their end separately links to each other with three-phase output end a, the b of three-phase half controlled bridge formula pressure regulation output circuit (4), the corresponding end of c, and the normally open contact KM2-1 other end separately of second A.C. contactor is the port that can link to each other with a corresponding end of the three-phase input end of alternating current machine (5) in use; Electric motor starting circuit (100) also has the self-locking contact KM2-2 of second A.C. contactor; Line current detects open-phase protection circuit (17) and is made up of current transformer (17-1), photoelectricity coupling circuit (17-2), second OR circuit (17-3), delayer (17-4) and second relay circuit (17-5); The coil of current transformer (17-1) is arranged on three-phase output end a, b, the c of three-phase half controlled bridge formula pressure regulation output circuit (4), the output of each current transformer (17-1) links to each other with the input of the corresponding photocoupler of photoelectricity coupling circuit (17-2), the output of photoelectricity coupling circuit (17-2) connects the input of second OR circuit (17-3), the output of second OR circuit (17-3) links to each other with the input of delayer (17-4), and the output of delayer (17-4) links to each other with the control end of second relay circuit (17-5); Second relay circuit (17-5) is provided with the second relay coil J2, the self-locking contact KM2-2 of second A.C. contactor of the second relay contact J2-1 and electric motor starting circuit (100) is cascaded, and is connected in parallel on the two ends of the starting switch of electric motor starting circuit (100).

10, according to the described intelligent powersaving device for AC motor of one of claim 1 to 8, it is characterized in that: the exportable 380V of interchange when the port that can be connected with the three-phase input end of alternating current machine (5) during the use of the controlled device of start-up circuit (100) is to use, exchange 660V or exchange the port of 1140V.