CN202282752U - Motor soft start controller of belt conveyor based on speed closed loop technology - Google Patents

Abstract

A motor soft start controller of a belt conveyor based on speed closed loop technology is composed of a voltage collection unit, a current collection unit, a synchronous signal detecting unit, a rotating speed feedback unit, a digital signal processor (DSP) control unit and a communication unit. The DSP control unit is respectively in electric signal connection with the voltage collection unit, the current collection unit, the synchronous signal detecting unit, the rotating speed feedback unit and the communication unit. The motor soft start controller achieves stable starting of motors, enables rotating speed of the motors to be the same in a multi-motor system, and prolongs service life of the motors and a belt.

Description

Soft starter for motor controller based on the technological ribbon conveyer of speed closed loop

Technical field

The utility model relates to Motor Control Field, is specifically related to a kind of soft starter for motor controller based on the technological ribbon conveyer of speed closed loop.

Background technology

Because AC asynchronous motor is simple in structure, reliable, easy care, the length of receiving a mandate, and be easy to process various degree of protection, and comprise the motor of explosive-proof grade, therefore in ribbon conveyer, extensively adopted.Traditional soft starter is effective to the starting of common electric machine; But the load of ribbon conveyer is different with other operating mode; Ribbon conveyer has loaded after certain material (for example coal cinder) above that, and its driving torque and rotating speed are irrelevant basically, therefore belongs to constant torque load.But the material that is loaded on the conveyer changes again all the time, and is many sometimes, and load is just heavy; Sometimes few, load is just light.Therefore the load of conveyer fluctuates again constantly.Since few for a long time during the load on the ribbon conveyer, therefore need under fully loaded various loads, start it from zero load.Because stiction is bigger than kinetic force of friction, the bigger moment of resistance after conveyer has than rotates when static also is that starting torque is greater than work moment, so the motor of conveyer should have big starting torque.If conveyer bears too big torque, for example starting is too fast, can cause the belt internal stress excessive, thereby reduces the life-span of belt.The value of belt accounts for ribbon conveyer total value 3/4ths.Practical operating experiences shows, the impact torque the when principal element that influences conveyer belt useful life is motor starting causes that belt tension increases severely, when serious even break belt.So the conveyer motor should not adopt the starting that directly gets access to grid.The kind of drive of ribbon conveyer has single cylinder transmission, twin-roll transmission, multiple-roll transmission.Cylinder transmission of monomotor list or the transmission of monomotor twin-roll are used for the less conveyer of power more.High-power conveyor adopts twin-roll bi-motor, the many drive of motor of multiple-roll more, can reduce the band internal tension like this, helps improving the life-span of belt.But note making each motor speed synchronous, reasonable distribution power.When using many motor-driven; Problem will be more serious; Under the situation of a plurality of motors/a plurality of soft starters, when starting, a motor can take place usually can bear more load than other motor, and can having only wherein when serious, the part motor rotates; All the other motor do not rotate, and the result causes motor tripping operation or belt to be broken.Come from the motor of same producer same model even this is, its mechanical electric performance also can not be identical.In addition when motor and soft starter were in diverse location, the power voltage-drop of variation and source impedance caused every equipment that different voltages with different is arranged.The selection that improves Electric Machine Control is exactly the transmission device of controlled reduced voltage starting; Because the loading range when the ribbon conveyer starting is addressed in the front alters a great deal, possibly be unloaded, also possibly be fully loaded; But also possibly be many motor-driven; But the principal element that influences the ribbon conveyer startup is a speed, and traditional soft starter for motor device is merely able to regulate the startup initial voltage and the electric current of motor, can't reach the function of control electric motor starting rotating speed.

Summary of the invention

This patent discloses a kind of controller that is directed against the soft starting device of ribbon conveyer, and it is the basis based on the speed closed loop technology, through detecting rotating speed of motor; Motor is started in the regulation rotating speed, in multi-motors drive system, make every rotating speed of motor unanimity; Quicken gradually, until reaching at full speed.

For achieving the above object; The technical scheme of the utility model is following: a kind of soft starter for motor controller based on the technological ribbon conveyer of speed closed loop; Be made up of voltage acquisition unit, current acquisition unit, synchronous signal detection unit, speed feedback unit, DSP control unit, driver element and communication unit, the DSP control unit is connected with voltage acquisition unit, current acquisition unit, synchronous signal detection unit, speed feedback unit, driver element, the communication unit signal of telecommunication respectively.

Motor speed, voltage, the current signal of when the controller of the soft starter device of speed closed loop technology is worked input being come in carry out computing; Calculate the silicon controlled trigger angle; Send out pwm signal then and trigger controllable silicon, the rotating speed during the control electric motor starting rises according to set-point, thereby has realized the smooth start of motor; In multi-machine system, can make the rotating speed of motor identical, prolong the useful life of motor, belt.

Description of drawings

Fig. 1 is the schematic diagram of voltage acquisition unit;

Fig. 2 is the schematic diagram of current acquisition unit;

Fig. 3 is for being the synchronous signal detection unit schematic diagram;

Fig. 4 is a speed feedback unit schematic diagram;

Fig. 5 is a DSP control unit schematic diagram;

Fig. 6 is the utility model structured flowchart; Wherein 1, voltage acquisition unit, 2, the current acquisition unit, 3, synchronous signal detection unit, 4, the speed feedback unit, 5, the DSP control unit, 6 communication units, 7, driver element.

Fig. 7 is this controller main program block diagram;

Fig. 8 is the subprogram figure of electric motor starting;

Fig. 9 is a pulse-triggered synchronizing signal interrupt routine block diagram;

Figure 10 is a SCR trigger pulse output program block diagram.

Embodiment

Embodiment 1

In belt conveyor system, all motor adopt the motor of same model, have essentially identical mechanical electric performance.Every motor is all used the solid-state soft starter control of a tape speed feedback closed loop control; Only adorned a tachometer (speed encoder) in the system; The d. c. voltage signal that its output frequency is directly proportional with speed; Because each soft starter will be shared same feedback speed signal, so feedback speed signal need be delivered to a frequency/voltage converter, it is the speed feedback impulse transfer signal of 0～3.3V.Its output signal is delivered to the speed feedback input of solid-state soft starter respectively through three signal isolators.Certainly, if adopt three speed encoders to make speed feedback signal usefulness in the system, it also is the same respectively connecing a frequency in the output of each speed encoder so.Because the existence of speed control closed loop, it can guarantee that the speed of controlled motor can follow given speed.If controlled motor speed is much smaller than given speed, then speed regulator can be exported maximum current, lets motor quicken with maximum current.If controlled motor speed is equal to or higher than given speed, then speed regulator output minimum current lets motor move with minimum current.Situation during the operation of separate unit motor is similar, and control is simpler, only needs a speed feedback device can accomplish the control to motor speed.

During speed closed loop control starting, the rotating speed when requiring the control electric motor starting rises by control law.The set-point of this programme is the tachometer value corresponding according to the torque slope that sets; Value of feedback is the realtime power factor angle that calculates according to the rotating speed that motor feeds back; It is carried out computing; Produce start pulse signal and control silicon controlled conducting and shutoff, control the output voltage size of soft starter device, thereby make the motor smooth starting.

The utility model device construction: this device is long 23.5CM, wide 12.6CM, and the cuboid of high 9.8CM, bottom of device is a binding post, the right medial side of device is a COM1, can show and parameter modification by external human-computer interface device.Install four corner edge places screw hole is housed, be used for fixing.The device top is left louvre and is used for dispelling the heat.

Fig. 1 is the schematic diagram of voltage acquisition unit.U0 is the input of voltage signal, connects the soft starter voltage transformer.High pressure becomes low voltage signal through voltage transformer after inserting soft starter, amplifies, adds behind forward bias voltage, the amplitude limit AD that sends into DSP from U2 output through this circuit and handle, as voltage detecting, overvoltage and under-voltage protection.N4B wherein, N4A is a discharge circuit, diode V49 is used for amplitude limit.

The each several part annexation: resistance R 266 meets voltage input signal and test point U0; Other end connecting resistance R265 and capacitor C 81; C81 other end ground connection GND2,6 pin of another termination integrated circuit of R265 N4B, 6,7 pin parallel resistance R267 and the capacitor C 84 of N4B; 5 pin connecting resistance R264, R264 other end ground connection.The 7 pin connecting resistance R269 of N4B, the other end connecting resistance R262 of R269 and 3 pin of integrated circuit N4A, another termination power+V1 of R262.8 pin of N4A meet power supply+V2, and 4 pin connect-V2, the 2 pin resistance R 263 that is connected with 1 pin; The output of R263 connects 3 pin of capacitor C 83 and resistance R 261 and bidirectional diode V49; 1 pin of V49 meets C83 and ground GND2, and 2 pin meet power supply+V1A, another termination test point U2 of resistance R 2611.

Fig. 2 is the schematic diagram of current acquisition unit, and IA1 is the input of current signal, connects the soft starter current transformer.Electric current becomes low current signal through the inner current transformer of soft starter when the soft starter actuating motor, handles through exporting the AD that sends into DSP from IA2 behind this circuit amplification, the amplitude limit, as current detecting, overcurrent, overload and underload protection.Wherein N8B is a discharge circuit, and diode V8 is used for amplitude limit.

The each several part annexation: resistance R 277 meets input signal IA1,5 pin of other end connecting resistance R83, capacitor C 124 and integrated circuit N8B, and the other end of R83 and C124 is ground connection GND1 all.Series resistance R1 between 6 pin of N8B and 7 pin; 7 pin connecting resistance R85 and the R278 of N8B, the other end ground connection GND2 of R278,3 pin of another termination capacitor C 29, resistance R 74 and the diode V8 of R85; Another termination of C29 GND2; 1 pin of V8 meets GND2, and 2 pin connect+V1A, 3 pin connecting resistance R74 and test point IB2.

Fig. 3 is the synchronous signal detection unit schematic diagram, is used for detecting current zero-crossing signal.Current signal is after amplifier N11A (LM239) amplifies, and through by ND5A, the window comparator that ND5B (ND5A, ND5B are LM393) forms obtains the zero cross signal of electric current, sends DSP to as synchronizing signal.

The each several part annexation: current signal connects the anode of capacitor C 213 after resistance R 301, is used for the filtering DC quantity, negative terminal connecting resistance R302 and resistance R 140, the other end ground connection of R302.2 pin of another termination N11A of R140, resistance R 126, capacitor C 50, the other end of R126 and C50 and 1 pin of N11A link to each other, 3 pin connecting resistance R303 and capacitor C 144, the other end of R303 and C144 links to each other, and ground connection.1 pin of N11A is output as the amplifying signal of electric current, receives 2 pin of ND5A through resistance R 73,5 pin of ND5B, and the 3 pin connecting resistance R1 of ND5A meet power supply+V1 then, and 5,6 pin of ND5B link to each other the junction ground connection GND2 of C28 and R2 through capacitor C 28 with R2.7 pin of ND5B and 1 pin of the ND5A resistance R 72 that is connected, other end connecting resistance R71 and the C27 of R72, and the tripod of bidirectional diode V9; Another termination power+V1 of R71; The 1 pin ground connection GND1 of the other end of C27 and V9,2 pin of V9 meet power supply+V1, and 3 pin are output as synchronizing signal.IAX is a test point.

Fig. 4 is a speed feedback unit schematic diagram, and motor converts rotating speed the direct current signal of 0-3.3V into through tachometer, is connected to then on the J10 terminal of soft start controller, sends DSP to after amplifying through this circuit and handles.

The each several part annexation: motor speed meter connecting terminal J10, the d. c. voltage signal of input 0-3.3V, C64 is used for filtering harmonic, and C64 parallel resistance R92 is used for protective circuit.R92 one terminating resistor R87, other end connecting resistance R88,9 pin of another termination integrated circuit of R87 U10C; U10C9 pin and 8 pin connect capacitor C 63 and resistance R 89; 10 pin of another termination U10C of resistance R 88 connect capacitor C 62 and resistance R 6, C62 and R6 other end ground connection simultaneously.The 8 pin connecting resistance R135 of U10C, the negative electrode of another terminating diode 1 of R135 and 2 anode connect 3.3V and ground then respectively, are used for voltage stabilizing.

Fig. 5 DSP control unit schematic diagram, voltage signal, current signal and synchronizing signal are input to the inner laggard row operation of DSP, draw the electromagnetic torque of current motor; Compare it and initial set-point again, draw the torque difference, calculate the magnitude of voltage that needs adjustment; Be converted into the trigger angle that needs adjustment again; And then be converted into pwm signal, and send the controllable silicon that start pulse signal comes the conducting soft starter through chip for driving IC3, control motor torque with this.IC 9 is the ADM2483 communication chip, link to each other with host computer to carry out communicating by letter of soft starting controller and host computer, thereby the host computer that carries out modification, starting operation control and the operation conditions of parameter shows.

The each several part annexation: after voltage, electric current, synchronizing signal send DSP to, send 4,6,8 pin that pwm pulse signal is given IC3 (74HC244 chip for driving), the IC32 pin meets power supply+V1; 20 pin connect+5V; 10 pin ground connection GND1,12,14,16 pin are output, the output start pulse signal.DSP is connected to 3,5,6 pin of IC9 (ADM2483 communication chip), and 1 pin meets power supply+V1,8 pin ground connection GND1, and 16 pin meet power supply+5V2,9 pin ground connection TGND2,12 pin and 13 pin connect host computer as 485 communication ends.

The software design of the utility model is following:

Fig. 7 is for the utility model structured flowchart is the main program block diagram of whole system, mainly accomplishes the work such as management, start-stop control, fault detect of system.

Fig. 8 is the subprogram figure of electric motor starting, mainly accomplishes the calculating of conduction angle, and compares with given tachometer value, calculates the torque difference.

Fig. 9 pulse-triggered synchronizing signal interrupt routine block diagram.Because the silicon controlled triggering signal as synchronizing signal, has only correct synchronizing signal could reliably, effectively trigger controllable silicon with current zero-crossing point, thereby guarantee soft carry out smoothly.Because soft starter reduces voltage effective value with the voltage chopping mode; The voltage waveform of its output is a non-sine, makes motor current waveform produce distortion, has brought difficulty for the hardware collection of current zero-crossing point; Added the synchronizing signal recognizer; Because the zero crossing of electric current is certainly between voltage over zero to 90 °, so be made as in this interval effectively when synchronizing signal falls into, does not handle otherwise be not made as synchronizing signal.This has just strengthened the accuracy of synchronizing signal, filtering unnecessary interference.

After synchronizing signal is confirmed, calculate silicon controlled through time-delay and trigger subprogram.Be that timer promptly picks up counting after system detects synchronizing signal, begin to send trigger impulse when counting down to zero.When power-factor angle shifted zero onto, Soft Start-up Process finished, and voltage pushes away and is sine wave.In order to guarantee constantly all have at least two to be conducted, except sending triggering signal, also need send supplements and dash, and will have the conducting of positive and negative phase to constitute the loop at each.Supplements is 60 ° towards differing with main pulse in principle, and adopts A to mend B, and B mends C, and the mode of C benefit A is sent supplements and dashed.Suppose that it is VT1 that silicon controlled is arranged as A phase positive controllable silicon, anti-phase is VT4, and B phase positive controllable silicon is VT3, and anti-phase is VT6, and C phase positive controllable silicon is VT5, and anti-phase is VT2.

The utility model is the controller that adopts the soft starter device of speed closed loop technology; This device is the control core of soft starter; After other signals such as the motor speed through the outside is gathered into, voltage, electric current are sent into the inner DSP of soft starting controller and are carried out computing; Send triggering signal and trigger controllable silicon, with the mode that changes the controllable silicon trigger angle voltage is carried out copped wave and handle and regulate motor end of incoming cables voltage swing, thereby regulate the electric motor starting electric current to external equipment.This device can effectively be controlled the toggle speed and the electric current of motor in the start-up course of motor, motor rotating speed is according to the rules started, until bypass.

Claims (1)

1. soft starter for motor controller based on the ribbon conveyer of speed closed loop technology; Be made up of voltage acquisition unit, current acquisition unit, synchronous signal detection unit, speed feedback unit, DSP control unit, driver element and communication unit, it is characterized in that: the DSP control unit is connected with voltage acquisition unit, current acquisition unit, synchronous signal detection unit, speed feedback unit, driver element, the communication unit signal of telecommunication respectively.

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