Exchange the flexible method of controlling operation and control circuit of magnetic motor
Technical field
The present invention relates to a kind of control method for exchanging magnetic motor, specifically a kind of flexible movement of exchange magnetic motor
Control method and control circuit.
Background technique
Exchange magnetic motor of the present invention refers to the magnetic force motion device to work with alternating current, including alternating electromagnetic braking
The products such as device, A.C. contactor and AC circuit breaker.This kind of product is typically all to be directly accessed AC network at present, is opened by power supply
The on-off of pass is switched on or switched off control to carry out exchange magnetic motor.
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.
Summary of the invention
An object of the present invention is just to provide a kind of flexible method of controlling operation 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 second object of the present invention is just to provide a kind of flexible control circuit for exchanging magnetic motor, to reduce AC magnetism
The power loss of dynamic device, improves the service life of exchange magnetic motor.
An object of the present invention is achieved in that a kind of flexible method of controlling operation for exchanging magnetic motor, is connecting
It exchanges in the performance loop of magnetic motor and concatenates the first electronic AC switch, in the both ends of exchange magnetic motor the second alternating electron in parallel
Switch, first electronic AC switch and second electronic AC switch connect with ON-OFF control circuit respectively, by switching
Control circuit controls first electronic AC switch and second electronic AC switch implements logical-disconnected change alternateed
It changes, to reach real on adjustment exchange magnetic motor by the pulsewidth modulation to the input ac voltage being applied on exchange magnetic motor
The size of border operating voltage, and then the purpose of its operating current size is adjusted, thus defeated to alternating electromagnet in exchange magnetic motor
Electromagnetic force is continuously adjusted out, to realize the flexible movement of exchange magnetic motor.
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.
The second object of the present invention is to what is be achieved: 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 exchange magnetic motor
On alternating voltage carry out pulsewidth modulation, with by adjusting be applied to exchange magnetic motor on real work voltage size, come
Adjust the size of its operating current;
Second electronic AC switch is connected in the both ends of exchange magnetic motor in parallel, for controlling exchange magnetic motor continuous current circuit
On-off;
DC power supply is connected in the incoming end of AC power source in parallel, for providing direct-current working volts for ON-OFF control circuit;With
And
ON-OFF control circuit, respectively with the control terminal of the first electronic AC switch, the control terminal of the second electronic AC switch and electricity
The signal output end of pressure sample circuit connects, for being handed over according to the setting value and sampled voltage signal control first of output electromagnetic force
Galvanic electricity sub switch and the second electronic AC switch implement logical-disconnected transformation alternateed, by being applied to exchange magnetic motor
On input ac voltage pulsewidth modulation, reach the size of real work voltage on adjustment exchange magnetic motor, and then adjust it
The purpose of operating current size, to be continuously adjusted to alternating electromagnet output electromagnetic force in exchange magnetic motor, to realize
Exchange the flexible movement of magnetic motor.
Flexibility control circuit of the invention further include:
Voltage sampling circuit is connected in the incoming end of AC power source in parallel, for detecting the amplitude and phase of communication power supply,
And sampled signal is input to ON-OFF control circuit.It, can be with real-time detection communication power supply by the way that voltage sampling circuit is added
Voltage fluctuation situation, and will test signal feedback to ON-OFF control circuit, in this way, can make soft by adjusting pulse width
The ac output voltage of property control circuit is more accurate, to be effectively reduced or even avoid the fluctuation of communication power supply
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, present invention flexibility control circuit is exactly to control alternating electromagnetic brake
A kind of flexible braking control circuit.As the flexible braking control circuit, input power is alternating current, and effective object is to hand over
Alternating electromagnet in galvanic electricity magnetic brake really replaces common power switch, to exchange with flexible braking control circuit
Electromagnet is controlled, and by carrying out high-frequency pulsed width modulation (PWM) control to the alternating supply voltage of input, adjusts the PWM wave
Duty ratio flow through exchange so that the virtual value for making to be applied to the pulse ac voltage on alternating electromagnet is continuously adjusted
(because of the filter action of inductance in alternating electromagnet, which is and the sine wave of power supply same frequency electricity the electric current of electromagnet
Stream) virtual value can be realized as being continuously adjusted, thus make alternating electromagnetic brake export electromagnetic force it is available from zero to
Continuously adjusting in original nominal value range, it is thus achieved that making the effective object of alternating electromagnetic brake (such as: elevator brake
Device, the large vehicle walking brake of gantry, the service brake of tower type crane slewing gear, belt conveyor and cableway
Etc. transmitting mechanicals service brake etc.) flexible braking purpose.
The present invention can exchange ac brake and A.C. contactor etc. magnetic motor and implement flexible action control, can make to exchange
Magnetic motor realizes the preferred working condition that high current starting, low current maintain, and thus can reduce the power loss of exchange magnetic motor,
Electroluminescent fever and the operating temperature rise for reducing exchange magnetic motor, have correspondinglyd increase control performance, the use reliability of exchange magnetic motor
And service life.Control circuit of the present invention 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 control circuit of the present invention, can greatly improve the control performance of effective object.
Control method of the present invention and control circuit of the present invention cannot be only used for ac brake, it may also be used for ac contactor
In the various exchange magnetic perPETual motion machines such as device, AC circuit breaker.
Detailed description of the invention
Fig. 1 is the circuit block diagram of flexible control circuit of the invention.
Fig. 2 is control mechanism schematic diagram of the present invention.
Fig. 3 is the working waveform figure of flexible control circuit of the invention.
Fig. 4 is the circuit block diagram of flexible control circuit embodiment 1 of the invention.
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 the object description specific embodiment of the invention with alternating electromagnetic brake.
As shown in Figure 1, present invention flexibility control circuit includes voltage sampling circuit 3, ON-OFF control circuit 4, direct current
The parts such as power supply 2, the first electronic AC switch 5 and the second electronic AC switch 6, the Breake Electromagnet in alternating electromagnetic brake
7 as control object is adjusted, and AC power source input 1 is communication power supply.
In the control principle drawing of the flexible control circuit of the present invention shown in Fig. 2, what is indicated in dotted line frame is exchange
The equivalent circuit of alternating electromagnet in electromagnetic brake.It is by an inductance LdWith a resistance RdWhat series connection was constituted etc.
Imitate circuit.Switch in figure 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 electronic AC switch K is connected to contact A, whole supply voltages are added on alternating electromagnet;Work as alternating current
When sub switch K is connected to contact B, communication power supply is disconnected, and alternating electromagnet is short-circuited, and voltage thereon is zero.Although this
When alternating electromagnet on voltage be zero, but the reason of because of inductive energy storage, still have electric current in alternating electromagnet and flow through.With suitable
Frequent switch electronic AC switch K, so that it is done continuous switching between contact A and contact B, so that it may make to act on exchange
Voltage u on electromagnetOVirtual value UOIt is continuously adjusted.Because alternating electromagnet is substantially linear element, flowed in inductance coil
The alternating current i crossedOVirtual value IOAlso continuously adjusting for equal proportion will be obtained, the electricity for causing alternating electromagnetic brake to export
Magnetic force F is continuously adjusted, it is thus achieved that the flexible braking of alternating electromagnetic brake.And the flexible control circuit of the present invention
Use, may make the electric current flowed through in inductance coil to be effectively reduced, the power loss of alternating electromagnetic brake is accordingly reduced,
The calorific value of alternating electromagnetic brake is also greatly reduced therewith, and the service life of alternating electromagnetic brake obtains stabilization therewith and mentions
Thus height overcomes the drawback that alternating electromagnet causes service life short because of fever.
In the idealization waveform diagram of the flexible control circuit of the present invention shown in Fig. 3, Fig. 3 (a) is the movement of this flexibility
The AC-input voltage u of control circuitIWaveform diagram;Fig. 3 (b) is applied to after the control circuit pulsewidth modulation of this flexibility
Alternating voltage u on alternating electromagnetic iron coilOWaveform diagram, wherein t1Be electronic AC switch K contact A conducting, contact B it is disconnected
The period opened, t2It is the period that contact A disconnects, contact B is connected, thus forms the pulsewidth modulation to alternating voltage;Fig. 3 (c)
It is the alternating current i that modulated alternating voltage acts in alternating electromagnetic iron coilOWaveform diagram.
The working principle that the present invention exchanges the flexible control circuit of magnetic motor is embodied in shown in formula (1) ~ (3), Fig. 2
Schematic diagram and idealization waveform diagram shown in Fig. 3 in.What formula (1) ~ (3) indicated is that flexible control circuit acts on
The calculation formula of the relationship of corresponding electrical parameter and output electromagnetic force on alternating electromagnetic iron coil.
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 technical goal of the invention.
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 AC power source that the present invention exchanges flexible control circuit input can be the electric mains such as 220V or 380V, can also
To be the alternating current of alternating current generator or other forms generation.For three-phase (or multiphase) circuit, flexible movement control of the invention
Method processed be similarly it is applicable, three (or multiple) single-phase flexible control circuits combinations of the invention generally can be used
It forms.Flexibility control circuit of the invention can be equipped with various backup types or online ups power.