Exchange the flexible control circuit of magnetic motor
Technical field
The utility model relates to a kind of control device for exchanging magnetic motor, specifically a kind of flexibility for exchanging magnetic motor
Control circuit.
Background technique
Exchange magnetic motor described in the utility model refers to the magnetic force motion device to work with alternating current, including alternating electromagnetic system
The products such as dynamic device, A.C. contactor and AC circuit breaker.This kind of product is typically all to be directly accessed AC network at present, by power supply
It switches on-off to carry out exchange magnetic motor and be switched on or switched off control.
Wherein, alternating electromagnetic brake is made using tripping spring and brake pushrod as upper brake mechanism, with alternating electromagnet
For a kind of electro-magnetic braking device of gate-opening mechanism.The advantages of alternating electromagnet is that action response speed is fast, particularly suitable as system
Workpiece in dynamic device give using;But the disadvantage is that due to more than the conducting wire in electromagnetic coil and being not easy under AC Condition
The reasons such as heat dissipation cause its fever serious, cause the case where burning coil to happen occasionally, therefore, short service life is alternating current
One main performance deficiency of magnetic brake.The presence of this problem and being not easily overcome property are sought so that people have to turn to
Ask the exploitation and use of DC electromagnetic brake.And DC electromagnetic brake can meet various application necks although long service life
Domain needs the use of life of product, but its existing greatest problem is precisely due to the inductance of electromagnetic coil is big, thus
Cause its action response time that can generally reach hundred Milliseconds or more.And the main technical requirements of brake are exactly " to stop, stop
Fastly, stop surely ", action response times more than several hundred milliseconds, which is undoubtedly, is difficult to meet brake operation needs, this is also
DC electromagnetic brake is difficult to the bottleneck problem being used widely.
For this purpose, people attempt to seek solution route in the calorific value for how reducing alternating electromagnetic brake.Although drop
There are many multiplicity for the heating system of low alternating electromagnetic brake, but its result is all to cause the structure of alternating electromagnetic brake multiple
It is miscellaneous, increased costs, product competitiveness decline.
Others exchange magnetic motors are also all there are because calorific value is big to influence service life the problem of, only alternating electromagnetic
The problem of brake, is the most prominent.
Utility model content
The purpose of this utility model is just to provide a kind of flexible control circuit for exchanging magnetic motor, to solve AC magnetism
Dynamic device is in use because calorific value is big, and service life is caused to reduce the problem of.
The utility model is realized in this way: a kind of flexible control circuit exchanging magnetic motor, comprising:
First electronic AC switch is connected in series in the performance loop of exchange magnetic motor, for being applied to AC magnetism
Alternating voltage on dynamic device carries out pulsewidth modulation, by adjusting the big of the real work voltage being applied on exchange magnetic motor
It is small, to adjust the size of its operating current;
Second electronic AC switch is connected in the both ends of exchange magnetic motor in parallel, returns for controlling exchange magnetic motor afterflow
The on-off on road;
DC power supply is connected in the incoming end of AC power source in parallel, for providing DC operation electricity for ON-OFF control circuit
Pressure;And
ON-OFF control circuit, respectively with the control terminal of the control terminal of the first electronic AC switch, the second electronic AC switch
Connect with the signal output end of voltage sampling circuit, for the setting value and sampled voltage signal control the according to output electromagnetic force
One electronic AC switch and the second electronic AC switch implement logical-disconnected transformation alternateed, by being applied to AC magnetism
The pulsewidth modulation of input ac voltage on dynamic device, reaches the size of real work voltage on adjustment exchange magnetic motor, and then adjusts
The purpose of its whole operating current size, so that alternating electromagnet output electromagnetic force in exchange magnetic motor is continuously adjusted, with
Realize the flexible movement of exchange magnetic motor.
The utility model further include:
Voltage sampling circuit is connected in the incoming end of AC power source in parallel, for detect communication power supply amplitude and
Phase, and sampled signal is input to ON-OFF control circuit.It, can be with real-time detection Alternating Current Power Supply by the way that voltage sampling circuit is added
The voltage fluctuation situation of power supply, and will test signal feedback to ON-OFF control circuit, in this way, can by adjusting pulse width,
Keep the ac output voltage of flexible control circuit more accurate, to be effectively reduced or even avoid communication power supply
Fluctuate the influence to flexible control circuit output voltage.
The ON-OFF control circuit is pulse-width modulation circuit, and output electromagnetic force is provided in the ON-OFF control circuit and is set
Determine circuit.
First electronic AC switch and/or second electronic AC switch can be using such as flowering structures: by two poles
Pipe VD1With diode VD2The first branch is formed in the way of cathode docking, by diode VD3With diode VD4With anode docking
Mode form second branch, the first branch is in parallel with second branch, in diode VD1With diode VD2Connecting node and
In diode VD3With diode VD4Connecting node between connect device for power switching V, the control electrode of device for power switching V is made
For the control terminal of electronic AC switch, to connection switch control circuit.
First electronic AC switch and/or second electronic AC switch can also be using such as flowering structures: by two
Pole pipe VD1With device for power switching V1Reverse parallel connection forms the first branch, by device for power switching V2With diode VD2Reversely simultaneously
Connection composition second branch, the first branch and second branch are connected in series, device for power switching V1Control electrode and power switch device
Part V2Control terminal of the control electrode as electronic AC switch, be used for connection switch control circuit.
For alternating electromagnetic brake, the utility model is exactly a kind of flexible braking for controlling alternating electromagnetic brake
Control circuit.As the flexible braking control circuit, input power is alternating current, and effective object is alternating electromagnetic brake
In alternating electromagnet, common power switch is really replaced with flexible braking control circuit, alternating electromagnet is controlled
System is controlled by carrying out high-frequency pulsed width modulation (PWM) to the alternating supply voltage of input, adjusts the duty ratio of the PWM wave, thus
The virtual value for making to be applied to the pulse ac voltage on alternating electromagnet is continuously adjusted, and flows through the electric current of alternating electromagnet
The virtual value of (because of the filter action of inductance in alternating electromagnet, which is the sine-wave current with power supply same frequency) is just
Can be realized it is continuously adjustable, so that the electromagnetic force for exporting alternating electromagnetic brake is available from zero to original nominal value range
Interior continuously adjusts, it is thus achieved that make alternating electromagnetic brake effective object (as: elevator brake, gantry
The work of the transmitting mechanicals such as large vehicle walking brake, the service brake of tower type crane slewing gear, belt conveyor and cableway
Make brake etc.) flexible braking purpose.
The utility model can exchange ac brake and A.C. contactor etc. magnetic motor and implement flexible action control, can make
It exchanges magnetic motor and realizes the preferred working condition that high current starting, low current maintain, thus can reduce the power of exchange magnetic motor
Loss reduces electroluminescent fever and the operating temperature rise of exchange magnetic motor, has correspondinglyd increase the control performance of exchange magnetic motor, using can
By property and service life.The utility model have small in size, at low cost, structure is simple, control flexibly, reaction is fast, operation and
The features such as easy to maintain, high reliablity.Since alternating electromagnet has the dynamic response characteristic more faster than DC electromagnet, because
This, controls alternating electromagnet using the utility model, can greatly improve the control performance of effective object.
The utility model cannot be only used for ac brake, it may also be used for the various friendships such as A.C. contactor, AC circuit breaker
It flows in magnetic perPETual motion machine.
Detailed description of the invention
Fig. 1 is the circuit block diagram of the utility model.
Fig. 2 is the utility model control mechanism schematic diagram.
Fig. 3 is the working waveform figure of the utility model.
Fig. 4 is the circuit block diagram of the utility model.
Fig. 5 is the circuit block diagram of the ON-OFF control circuit constituted using single-chip microcontroller.
Fig. 6 is the software flow block diagram of single-chip microcontroller in ON-OFF control circuit.
Fig. 7 is the circuit diagram of the ON-OFF control circuit constituted using hardware circuit.
Fig. 8 and Fig. 9 is the circuit diagram of two kinds of specific implementations of electronic AC switch.
Specific embodiment
It is below to be adjusted object description specific embodiment of the present invention with alternating electromagnetic brake.
As shown in Figure 1, the utility model includes voltage sampling circuit 3, ON-OFF control circuit 4, the friendship of DC power supply 2, first
The parts such as galvanic electricity sub switch 5 and the second electronic AC switch 6, Breake Electromagnet 7 in alternating electromagnetic brake is as being adjusted
Control object, AC power source input 1 are communication power supply.
In the control principle drawing of the utility model shown in Fig. 2, what is indicated in dotted line frame is in alternating electromagnetic brake
Alternating electromagnet equivalent circuit.It is by an inductance LdWith a resistance RdThe constituted equivalent circuit of series connection.In figure
Switch represents electronic AC switch K.It includes contact A and contact B, and electric shock A connects power supply, and contact B connects alternating electromagnet.When
When electronic AC switch K is connected to contact A, whole supply voltages are added on alternating electromagnet;When electronic AC switch K is connected to touching
When point B, communication power supply is disconnected, and alternating electromagnet is short-circuited, and voltage thereon is zero.Although at this time on alternating electromagnet
Voltage be zero, but the reason of because of inductive energy storage, still have electric current in alternating electromagnet and flow through.Switched with suitable frequent and is handed over
Galvanic electricity sub switch K makes it do continuous switching between contact A and contact B, so that it may make to act on the voltage on alternating electromagnet
uOVirtual value UOIt is continuously adjusted.Because alternating electromagnet is substantially linear element, the alternating current i flowed through in inductance coilO
Virtual value IOAlso continuously adjusting for equal proportion will be obtained, the electromagnetic force F for causing alternating electromagnetic brake to export is obtained continuously
It adjusts, it is thus achieved that the flexible braking of alternating electromagnetic brake.And the use of the utility model, it may make in inductance coil and flow
The electric current crossed is effectively reduced, and the power loss of alternating electromagnetic brake is accordingly reduced, and the calorific value of alternating electromagnetic brake is also
Be greatly reduced therewith, the service life of alternating electromagnetic brake obtains stablizing raising therewith, thus overcome alternating electromagnet because
The drawback generated heat and cause service life short.
In the idealization waveform diagram of the utility model shown in Fig. 3, Fig. 3 (a) is the friendship of this flexibility control circuit
Flow input voltage uIWaveform diagram;Fig. 3 (b) is to be applied to alternating electromagnetic iron wire after the control circuit pulsewidth modulation of this flexibility
Alternating voltage u on circleOWaveform diagram, wherein t1It is the period of contact A conducting, the contact B disconnection of electronic AC switch K, t2
It is the period that contact A disconnects, contact B is connected, thus forms the pulsewidth modulation to alternating voltage;Fig. 3 (c) is modulated friendship
Galvanic electricity pressure acts on the alternating current i in alternating electromagnetic iron coilOWaveform diagram.
The working principle of the utility model is embodied in formula (1) ~ (3), schematic diagram shown in Fig. 2 and reason shown in Fig. 3
In wanting waveform diagram.What formula (1) ~ (3) indicated is corresponding to flexible control circuit acts on alternating electromagnetic iron coil
Electrical parameter relationship and export electromagnetic force calculation formula.
By Fig. 2, Fig. 3 and formula (1) ~ (3) as it can be seen that when input virtual value is UIAlternating current when, adjust alternating electron open
Close the turn-on time t of K contact A1And/or turn-off time t2, can make the voltage effective value U on alternating electromagnetOGenerate variation
(formula (1)) correspondingly flows through the electric current I of alternating electromagnetOContinuous adjusting (formula (2)) have been obtained, thus can make to exchange
For electromagnetic brake in the case where other electromechanical parameters are constant, the electromagnetic force F of output is continuously adjusted (formula accordingly
(3)), to achieve the purpose that flexible braking (brake), it is thus achieved that the technical goal of the utility model.
Voltage sampling circuit in Fig. 4 is by resistance R1With resistance R2Series arm composed by connecting, the series arm is simultaneously
Connection is connected to the both ends of alternating current input power supplying.By resistance R1With resistance R2Between connecting node on lead, be connected to switch control
Circuit, so that it may by the detection signal u of the detected amplitude about communication power supply and phasecPass to switch control electricity
Road.Voltage sampling resistor R1And R2It can also be replaced with components such as voltage sensors.
It should be noted is that voltage sampling circuit is not required in that in flexible control circuit, there is this electricity
Sample circuit is pressed, only in AC power source input voltage UIWhen fluctuating, the voltage U on alternating electromagnet can be madeOIt is conditioned
It is more accurate.
DC power supply in Fig. 4 is that the alternating voltage of input is converted to low-voltage DC, is provided for ON-OFF control circuit
DC supply needed for work.DC power supply can be obtained by Switching Power Supply, can also be obtained by linear power supply.
ON-OFF control circuit in Fig. 4 is using pulse-width modulation circuit, either using single-chip microcontroller as the intelligence of core
Energy circuit (Fig. 5), is also possible to the circuit common (Fig. 7) being formed by overlapping by hardware circuit.
In the embodiment of ON-OFF control circuit shown in Fig. 5, IC chip PIC12F675 is as pulsewidth modulation electricity
The main body on road, the output end of voltage sampling circuit are connected to 7 foot input terminals of IC chip, 5 feet of IC chip
Input terminal is connected to potentiometer RWSliding end.Potentiometer RWFor the output electromagnetic force setting electricity being arranged in ON-OFF control circuit
Road.Adjust potentiometer RWThe setting value of changeable alternating electromagnetic brake output electromagnetic force.Exporting electromagnetic force initialization circuit can also
Use the components such as key, encoder or toggle switch.ON-OFF control circuit is according to potentiometer RWSetting value and voltage inspection
Survey signal uc, by applying continuous pulse drive signal K to the first electronic AC switch and the second electronic AC switchAAnd KB,
I.e. controllable first electronic AC switch and the second electronic AC switch are connected and disconnect with alternateing.First alternating electron is opened
When closing conducting, the second electronic AC switch is disconnected;Conversely, the second electronic AC switch is led when the first electronic AC switch disconnects
It is logical.And the on-off switching time of two electronic AC switches is relative to its t1+ t2The control period for can be ignored.It should
Though circuit has the setting of voltage sampling circuit, can be used according to the needs of control precision in a control program, it can also be with
It is not used.
As shown in fig. 6, the specific workflow that ON-OFF control circuit is smart circuit is: single-chip microcontroller is after initialization, first
Inquire potentiometer RWOn voltage, to determine output duty cycle, in the turn-on time t for calculating the first electronic AC switch1Afterwards,
Instruction control the first electronic AC switch conducting is issued, while the second electronic AC switch being instructed to disconnect;It is exchanged in judgement first
The turn-on time t of electronic switch1It has been terminated that, calculate the turn-off time t of the first electronic AC switch2Afterwards, instruction control the is issued
One electronic AC switch disconnects, while instructing the conducting of the second electronic AC switch;In the disconnection for judging the first electronic AC switch
Time t2It returns at the end of, is recycled into subsequent work.So it can be realized to the alternating current being applied on Breake Electromagnet
It the pulsewidth modulation of pressure and continuously adjusts.
In the ON-OFF control circuit being formed by overlapping with hardware circuit shown in Fig. 7, the 3rd foot of 555 time base circuits is exported
The driving circuit of the first electronic AC switch and the driving circuit of the second electronic AC switch are tapped, when the 3rd foot exports high level
When, the conducting of the first electronic AC switch of driving, the second electronic AC switch disconnect;When the 3rd foot exports low level, driving first
Electronic AC switch disconnects, the second electronic AC switch is connected, and is achieved in the mutual negative actuation of switch of two electronic AC switches.
First electronic AC switch and the second electronic AC switch can use Fig. 8 or electronic AC switch shown in Fig. 9
Structure type, naturally it is also possible to can be realized the circuit structure form of the function using other.
Electronic AC switch in Fig. 8 is by diode VD1With diode VD2First is formed in the way of cathode docking
Road, by diode VD3With diode VD4Second branch is formed in the way of anode docking, the first branch is in parallel with second branch,
In diode VD1With diode VD2Connecting node and in diode VD3With diode VD4Connecting node between connect function
Rate switching device V, the positive output end of device for power switching V are connected to diode VD1With diode VD2Connecting node on, power is opened
The negative output terminal for closing device V is connected to diode VD3With diode VD4Connecting node on, the control electrode of device for power switching V is made
For the control terminal of electronic AC switch, to connection switch control circuit.
Electronic AC switch in Fig. 9 is by diode VD1With device for power switching V1Reverse parallel connection forms the first branch,
By device for power switching V2With diode VD2Reverse parallel connection forms second branch, and the first branch and second branch are connected in series, function
Rate switching device V1Control electrode and device for power switching V2Control terminal of the control electrode as electronic AC switch, to connect
ON-OFF control circuit.Diode VD in the first branch1With the diode VD in second branch2It can be with the side of anode docking
Formula is connected, and is also possible to be connected in such a way that cathode docks.
Device for power switching in above two electronic AC switch can select metal-oxide-semiconductor, triode or IGBT constant power
Device.The utility model input AC power source can be the electric mains such as 220V or 380V, be also possible to alternating current generator or
The alternating current that other forms generate.For three-phase (or multiphase) circuit, three (or multiple) the utility model generally can be used
Single-phase flexibility control circuit is composed.The utility model can be equipped with various backup types or online ups power.