Referring to Fig. 1, the present invention includes the anti-interference rectification filtering module 2 that directly is connected with alternating current input power supplying 1, this immunity module 2 is used to prevent that surge impact and fast-pulse group from disturbing, alternating current input power supplying 1 is after anti-interference rectification filtering module 2 rectifications, become frequency and be after the pulsating dc voltage of 100Hz by the high-pressure electrolysis capacitor filtering, become the less direct voltage of ripple.This direct voltage is divided into two-way, the adjustment of internal electric source module 6 of leading up to becomes+5V and+two output voltage of 20V, this two-way voltage is respectively electric current and voltage sampling/isolation module 7, central processing unit 9, isolated drive circuit 8 provides operating voltage.Electric current and voltage sampling/isolation module 7 utilizes the principle of A/D conversion, gathers voltage signal by the mode of single channel sampling, takes current signal by the mode of two-way difference, has finished the function of Signal Spacing in the process of sampling simultaneously.Electric current and voltage sampling/isolation module 7 is taked voltage signal from the output of contactor coil 3, and after having finished A/D conversion and isolation, gives central processing unit 9 with digital signal transfers.
Central processing unit 9 by voltage data and the current data that collects, is judged the residing operating state of major loop, the external voltage state.When external voltage signal met the demands, central processing unit 9 was carried out attracting process.
The control signal that central processing unit 9 sends, transmit by isolated drive circuit 8, this isolated drive circuit 8 plays level conversion, improve the effect of output signal driving force and buffer circuit, this part adopts high speed photo coupling device and push-pull circuit to guarantee to export the integrality of control signal and the raising of driving force.Drive signal after the isolation is applied directly to the gate pole of MOSFET module 4 to reach the purpose of control MOSFET module 4 break-makes.MOSFET module 4 is connected in the power supply major loop directly to be connected to reach with anti-interference rectification filtering module 2 outputs and contactor coil 3 regulates the purpose that is applied to voltage on the contactor coil 3 and opens, turn-off the contactor control loop.
Protection module 5 directly links to each other with MOSFET module 4 with contactor coil 3; at MOSFET module 4 or anti-interference rectification filtering module 2 because of contingency; when reasons such as end useful life puncture or damage, circuit is forced to turn-off a period of time, to guarantee the safe operation of control circuit and contactor.
Anti-interference rectification filtering module of the present invention 2 is by piezo-resistance, ceramic disc capacitor, and rectifier bridge, choke, electrochemical capacitor is formed; Rectification circuit adopts unidirectional full-bridge rectification pattern.Piezo-resistance is applied to resist surge, and high-voltage capacitance and choke are used to eliminate fast-pulse group's interference.Electrochemical capacitor is used for eliminating voltage ripple and removes the overvoltage that switching process occurs.
Referring to Fig. 2, anti-interference rectification filtering module 2 of the present invention comprises the JP1 input connector that is connected with alternating current input power supplying 1, and alternating current is imported thus; Be connected to rectifier bridge D1 repeatedly on the JP1 input connector, and on rectifier bridge D1, also be connected with three high capacitance C1, C2, C3 and three piezo-resistance R1, R2, R3, the first high-voltage capacitance C1 and second high-voltage capacitance C2 polyphone and with the 3rd high-voltage capacitance C3 and connect wherein, the first piezo-resistance R1 and second piezo-resistance R2 polyphone back and the 3rd piezo-resistance R3 also connect, and wherein high-voltage capacitance is used to absorb fast-pulse group interference, and piezo-resistance will be used to resist surge impact.Rectifier bridge D1, selection capacity are 3A, the contactor after optimizing the startup stage electric current at 1-3A, remain on 200-400mA at sticking stage electric current.
The output 2 of rectifier bridge among Fig. 2 is connected with DC_OUT among Fig. 5 with Fig. 3.
Referring to Fig. 3, the input of the 6th diode D6 of internal electric source module 6 is connected with the output of the rectifier bridge D1 of anti-interference rectification filtering module 2, the output of the 6th diode D6 links to each other with the 8th pin of power supply chip U1, the 6th resistance R 6 is connected elementary in parallel with transformer T1 as the voltage absorption circuit with the 7th capacitor C 7 backs in parallel with the 7th diode D7,4 of power supply chip, 5,8 leads ends are respectively by the 8th capacitor C 8, the 5th capacitor C 5 and the 6th capacitor C 6 ground connection, first of transformer T1 be secondary to pass through the 9th diode D9 rectification and by the tenth capacitor C 10, output+5V voltage after the ∏ mode filter filtering that the first coil L1 and the 11 capacitor C 11 are formed, this filter is in digitally linking to each other, the tenth resistance R 10 that is attached thereto and light-emitting diode D11 are as the indication of power supply, another of transformer is secondary through the 8th diode D8 rectification, and the voltage by output+20V after 9 filtering of the 9th capacitor C, the negative pole of the 9th diode D9 connects simulation ground.Photoelectrical coupler U2 is connected with the 9th diode D9, be used to detect the output of the 9th diode D9,2 ends of photoelectrical coupler U2 link to each other with the 4.3V voltage-stabiliser tube, and its 4th end links to each other as the input of Voltage Feedback with the 5th pin of power supply chip U1, and its 3rd end is connected with simulation ground.Internal electric source module 6 of the present invention is mainly central processing unit 9, and electric current and voltage sampling/isolation module 7 and isolated drive circuit 8 provide working power.In order to satisfy industrial instructions for use, this integrated circuit is had relatively high expectations to power supply.In order to reach anti-interference preferably purpose, internal electric source module 6 of the present invention is the two-way insulating power supply; Wherein+and 20V links to each other with the system major loop, and+5V is isolated into CPU module 9 power supplies fully, and power supply chip adopts the FSD311 chip of FAIRCHILD company, produces two-way output gross power and be 3 watts insulating power supply, and its power supply is set up speed at 3~15ms.Internal electric source module 6+the 5V power supply directly links to each other with the 8th pin VCC of single-chip microcomputer, is connected with the 4th resistance R 4, the five resistance R 5 simultaneously, for single-chip microcomputer reset signal and power supply indication LED provide power supply.Simultaneously internal electric source module 6+5V provides power supply for the isolation optocoupler of electric current and voltage sampling/isolation module 7 and the digital side of output isolation optocoupler.Internal electric source module 6+20V provides working power for the sampling A and the output driving circuit of electric current and voltage sampling/isolation module 7 and isolated drive circuit 8.
Referring to Fig. 4, central processing unit 9 is accepted the voltage and current signal on the contactor coil that data sampling obtains, by Processing Algorithm output control signal, drives external circuit.Satisfy anti-interferencely for fine, the ATTINY series monolithic of atmel corp has been selected in the requirement of miniaturization, the present invention.This single-chip microcomputer has abundant internal resource: built-in A/D modular converter is arranged, PWM output port, built-in crystal oscillator, and ISP function.This processor volume is little simultaneously, can satisfy the requirement of miniaturization when integrated.One-chip machine port TXD_SCK, RXD_SDA, DRV, GND, the interface in the terminal in RST end and its left side links to each other, and is used to download.The 4th resistance R 4 respectively with+5V, the reseting port of the 12 capacitor C 12 and monolithic is connected, the 5th resistance R 5 and LED D12 be connected on+the RXD_SDA end of 5V and single-chip microcomputer between as the operating state indication of single-chip microcomputer.The output port DRV output control signal that is connected with 3 ends of U6 among Fig. 6 simultaneously, TXD_SCK holds and is connected with 3 ends of U5 among Fig. 5, as the input of voltage sample.
Referring to Fig. 5, electric current and voltage sampling/isolation module 7 is realized by the means that detect voltage difference.In the middle of the electric current major loop, add noninductive sample resistance,, voltage transitions is become the frequency signal input central processing unit 9 of 50-100KHz at sample resistance front and back stages sampled voltage and carry out voltage sample respectively respectively by the mode of voltage-frequency conversion.Under this condition, its voltage resolution can reach the required precision of current detecting fully at interchange ± 0.15V.In this circuit, be core with chip U4, its 8th pin is that power end directly is connected with+20V power end.The 12 resistance R 12 of connecting among the figure, the 13 resistance R 13, the 14 resistance R 14 and the 22 resistance R 22 play the dividing potential drop effect in the voltage sample process, the 12 resistance R 12 links to each other the 22 resistance R 22 and the 16 capacitor C 16 ground connection in parallel with rectification output.The 22 resistance R 22 minutes the 7th pin of voltage input chip U4; The 5th pin of chip U4 is connected with+20V power supply by the 15 resistance R 15 respectively, and the 14 capacitor C 14 links to each other with simulation ground.The 2nd pin of chip U4 is connected with simulation ground by the 23 resistance R 23; The 17 capacitor C 17 by parallel connection after the 1st pin of chip U4 and the 6th pin parallel connection is connected with simulation ground with the 15 resistance R 15; Output the 3rd pin of chip U4 is connected the back by the 18 resistance R 18 and is connected in the 1st pin of optocoupler U5 with+20V power supply, be connected to the 2nd pin of optocoupler U5 and simulation; The 4th pin of optocoupler U5 is connected with the 5V power supply, and the 3rd pin of optocoupler U5 is by the 24 resistance R 24 ground connection, and the 3rd pin of optocoupler U5 directly is connected with the TXD_SCK of single-chip microcomputer.
Referring to Fig. 6, isolated drive circuit 8 is to isolate and two purposes of signal amplification in order to reach: because the pwm signal frequency higher duty cycle of central controller 9 outputs is very little, the wave distortion in the photoelectricity transmission process is bigger.By using high speed photo coupling to cooperate the type of drive of push-pull circuit, guaranteed the accuracy that control signal is transmitted, improved the driving force of control signal simultaneously.The 2nd pin of this circuit chips U6 links to each other with+5V power supply by the 20 resistance R 20, and the 3rd pin of chip U6 is exported the DRV signal with single-chip microcomputer and is connected; Its 8th pin directly is connected with+20V power supply, and is connected and simulates ground by the 13 capacitor C 13 and its 5th pin 5 back that links to each other; The 6th pin of chip U6 is connected to+20V power supply and be connected to simulation ground by the 15 capacitor C 15 by the 21 resistance R 21, should directly link to each other with the base stage of the 3rd triode Q3 and the second triode Q2 by end simultaneously; 2 ends of the 3rd triode Q3 are connected with+20V voltage, and its 3 end is connected with 2 ends of the second triode Q2 and exports the controlled stage of MOSFET, the 3rd termination simulation ground of the second triode Q2 to.By the 3rd triode Q3, the gate pole of MOSFET module 4 directly links to each other among the output of the push-pull circuit that the second triode Q2 forms and Fig. 7, and drive signal is passed to MOSFET module 4 among Fig. 6.
Referring to Fig. 7, it is that the power MOSFET of STU10NB80 and the P6KE300 voltage-stabiliser tube of series connection are formed that MOSFET module 4 adopts model.This power device volume is little, and peak value is withstand voltage, and the 900V of reaching peak current can reach 9A, satisfies the requirement of voltage, electric current two aspects, and sufficient surplus is arranged.And its conducting resistance is little, and thermal losses is very little under the operating state.For the TVS of MOSFET parallel connection is in order to absorb instantaneous energy, to prevent that MOSFET is damaged under the breakdown situation of major loop.The 4th diode D4 that connects among Fig. 7, the 2nd, the 3 pin parallel connection of the 5th diode D5 and MOSFET, the 5th diode D5 is connected with simulation ground by electric nine resistance R 9 with the common port of the first triode Q1.Wherein the common port of the first triode Q1 and the 4th diode D4 links to each other with contactor coil, is used for the average voltage on the regulating winding.Monitor simultaneously the 9th resistance R 9 two ends respectively with Fig. 8 in 2,4 two ends of U3 be used for the threshold supervision of electric current.
Referring to Fig. 8, protection module 5 mainly is made up of comparator.After in current circuit, sealing in noninductive sample resistance, its both end voltage detected can obtain loop current value, by with the comparison of reference voltage, judge whether electric current surpasses allowed band.This module will drag down the control signal of monolithic output by force under the excessive situation of electric current, thoroughly turn-off MOSFET and then cut off control loop.The 1st pin of Fig. 8 chips U3A is connected with the 13 diode D13; Its 8th end directly links to each other with+20V power supply, and its 3rd pin is connected to+the 20V power supply by the 7th resistance R 7, simultaneously by the 8th resistance R 8 and simulation be connected, the 2nd, 4 pin of this chip U3A respectively with Fig. 7 in the 9th resistance R be connected at two ends about in the of 9.6 ends of chip U6 among the input 136_OUT of the 13 diode D13 and Fig. 6 are connected, and are used for forcing to drag down the U6 output signal.
The startup stage of A.C. contactor,, therefore, it is calculated, to obtain the rate of change of electric current in the coil by gathering the voltage signal at contactor coil 3 two ends because the electric current change curve does not change with the variation of external voltage in the coil.In the early stage process,, as shown in Figure 9, and its normalization data deposited in the central processing unit 9 by the relation between probe of contactor displacement and the current changing rate of obtaining of a large amount of tests.In program, call these data and compare with the current changing rate that calculates and can obtain the contact displacement, and the voltage of adjusting the contactor coil two ends in view of the above is to reach the purpose of electric current in the regulating winding.Along with the variation of electric current, can constantly the changing with joint efforts of suction in the electromagnetic mechanism and counter-force.By the amplitude and then the feasible opposite direction of pointing to the contact motion with joint efforts gradually of regulating electric current, finally control dynamic/static contact with optimization speed closure.
Traditional A.C. contactor is because the alternating voltage control contactor of the pulsation of using must install the vibration that divided magnetic ring just can weaken iron core additional in electromagnet system.And the present invention will control power supply and carry out rectification and adopt the direct current mode to carry out the control of contactor, and original vibration problem can be eliminated, and the lot of energy loss also can be eliminated on original divided magnetic ring simultaneously.
When the conventional AC contactor is worked at the pick-up voltage lower limit, can produce serious contact jitter phenomenon, this phenomenon can cause serious contact arcing and ablation, thereby significantly shortens the useful life that causes contactor.Identical under the operating state of contactor of the present invention when the pick-up voltage lower limit is worked and the rated voltage, outside lower limit, can disconnect the contactor control loop immediately and discharge contact.
Conventional AC contactor electromagnetic mechanism is in order to reach aim of stable operation in full voltage range, and the consumption of its copper, iron is all very big.Because the present invention has adopted hvdc control mode, the sectional area of contactor electromagnet and the requirement of coil turn is reduced greatly, thereby reach the purpose of saving with iron amount and copper consumption.
For reaching the purpose of optimizing existing contactor mechanical performance, electrical property, operating efficiency, performance characteristic that should corresponding original contactor is studied.According to stipulating in the national standard that A.C. contactor should be finished the adhesive of electromagnetic system and effectively keep this state under 85% ~ 110% rated voltage, any point between 70% to 20% rated voltage discharges contact and promptly is considered as reaching standard-required.Also may adhesive in the process of practical operation at contactor under 70% voltage or on 110% voltage range.
In the full voltage range of contactor work, line voltage all is applied in the contactor coil two ends, makes that contactor motion state during adhesive under different voltages is inconsistent.Be operated in rated voltage when above, the probe of contactor closing speed is very fast, and impact kinetic energy is bigger between contact, causes that stronger arcing phenomenon and contact ablate thereby cause moving contact that repeatedly vibrations take place.The contact movement velocity is slower when being lower than rated voltage, even closed unstable contact strenuous vibration can take place, thereby causes the major injury of contact, reduces its electric life significantly.
By the analysis of above problem, the present invention draws the Based Intelligent Control scheme of following optimization:
(1) referring to Figure 10, contactor under the DC control condition, in its coil the electric current change curve as shown in the figure, under different voltage magnitudes, corresponding variation can take place in current amplitude, but that its rate of change keeps stablizing is constant.Can in time judge contact, displacement unshakable in one's determination by detection to the current changing rate in the coil.Thereby adjust the output control signal on this basis.
(2) behind contactor control power connection, application-specific integrated circuit (ASIC) detects control voltage, judges whether master control voltage reaches the control threshold value.If reach this value, then enter starting state and in EEPROM, inquire about Control Parameter.Its Control Parameter changes as shown in figure 11, in the moving part accelerated motion of initial start stage with higher average voltage and bigger current drives contactor electromagnetic mechanism, the judgement of the rate of change by electric current and the delay procedure of locking, before contact closure, reduce the contact movement velocity, reduce its spring; Before the iron core collision, adjust its control voltage to reach the purpose that reduces impact velocity unshakable in one's determination once more.
(3) after the contactor closure, after the high voltage time-delay by in short-term guarantees the steady closure of contact, control voltage is adjusted within the 10V to reach the low power operation of contactor.
(4) after closure within the scope of contactor in GB regulation, variation has taken place in external voltage.The scope that voltage fluctuation has exceeded the GB regulation is the monitoring by sample circuit then, is lower than 75% or be higher than under the 120%Ue voltage condition at voltage, makes intelligent control unit can cut off control loop and then cuts off main current loop.
(5) in the contactor running,, judge that by the variation of electric current probe of contactor is residing position in closing course by comparing to the sampling of voltage, electric current and with data and original test data that sampling obtains.In the closing course of contactor, though keep the electromagnetic mechanism coil in voltage remain unchanged, can cause that along with variation fast takes place the air gap between the dynamic and static contact winding inductance quantity changes significantly.Thereby cause under the constant situation of voltage and resistance, violent fluctuation can take place in the electric current in the coil, and such electric current is the common characteristics of all A.C. contactors with the contact displacement changing curve.Therefore judge that by the rate of change of electric current the displacement of contact and stroke can arrive determine effect accurately.
(6) phase I shown in Fig. 4 be contact closure the startup stage, should bigger voltage and higher energy be arranged holding circuit in this stage.Behind the contact setting in motion, enter second stage, judge the displacement of contact, constantly change the PWM waveform of control unit output even turn-off control loop in short-term and reach optimum with the closing speed that keeps dynamic and static contact according to the electric current change curve.Intelligent control unit enters the operation of phase III after contact closure: control unit is turned down control voltage once more, until it is unshakable in one's determination closed, behind closed the stablizing unshakable in one's determination, the voltage at the two ends of coil is adjusted to very low grade, can realize the energy-conservation stable operation of contactor like this.Simultaneously, because voltage is very low in this process, energy is very little so the coil heating that causes also can reduce greatly, so also increased the stability that contactor moves.Can obtain contact movement velocity curve among Figure 12 by the voltage-regulation pattern among Figure 11.
(7) by this control mode, can guarantee that A.C. contactor is in the GB specified operating range, the operating state that can be consistent, promptly keeping in touch the device adhesive in the full voltage working range keeps strokes, keep identical power consumption in stationary operational phase simultaneously, can not occur the situation of contact strenuous vibration when under critical voltage, working.
(8) owing to adopt the mode of direct current supply, can not occur the situation of current over-zero in the contactor running, therefore can not produce, the high-frequency vibration between iron core has also been eliminated the work noise that produces because of vibrations.
Experimental result and analysis
The present invention be directed to the intelligence control method based on current-varying mode of A.C. contactor.Its purpose is following 3 points: serve as that the A.C. contactor product of controlling core can significantly reduce raw-material use amounts such as copper, iron after optimizing with this application-specific integrated circuit (ASIC) 1,, reduce the contactor cost.2, the startup stage according to the rate of change of electric current, reduce the closing speed of contact and iron core, reduce the vibration and the spring of contact, thereby prolong the contactor life-span.3, in the sticking stage, hold-in winding voltage significantly reduces the contactor operation energy consumption at lower numerical value.Therefore,, the order at above 3 replication experiment is exactly in order to verify the effect of Based Intelligent Control from these three aspects: the present invention is to iron core weight for this reason, and coil turn and weight are measured; Spring and vibration to the adhesive stage have been done to measure and contrast; Sticking stage contactor power consumption is measured and contrasted.Thereby verified application-specific integrated circuit (ASIC) energy-conservation, noise reduction reduces vibration, the effect of aspects such as life-saving.
The present invention is directed to the CJ20-250 contactor to the carrying out of this application-specific integrated circuit (ASIC) the checking of principle and function, the rated voltage of these two kinds of contactors is 220V, the rated current of contactor major loop is 250A.
CJ20-250 A.C. contactor and the contrast of intelligent contactor copper iron consumption
|
Iron core |
Coil (Ue:220v) |
Coil (Ue:380v) |
Former CJ20-250 quality (kg) |
3.521 |
0.57 |
0.48 |
CJ20-250 quality (kg) after the optimization |
1.612 |
0.3 |
0.22 |
Save percentage |
46% |
54% |
46% |
Vibration number, time and holding power contrast
No Based Intelligent Control:
|
The contact vibration number |
Contact time of vibration (ms) |
Holding power (W) |
180V |
4 |
0.6 |
41.6 |
220V |
4 |
0.7 |
65 |
240V |
5 |
3 |
78 |
Under the Based Intelligent Control of the present invention:
|
The contact vibration number |
Contact time of vibration (ms) |
Holding power (W) |
180V |
2 |
0.4 |
2.1 |
220V |
2 |
0.4 |
2.1 |
240V |
2 |
0.4 |
1.9 |
Can draw by above contrast: along with the increase of voltage, the increase that the energy consumption of the contactor of no Based Intelligent Control when vibration, closing time, operation all can be linear.But by behind this Based Intelligent Control scheme optimization, its electric property increases substantially, and can keep identical electric and mechanical property under each electric pressure.After the optimization, probe of contactor reduces significantly at the vibration number and the time of vibration in adhesive stage in full voltage range, and the power consumption in the sticking stage reduces significantly, and fractional energy savings is more than 90%.