CN106452270A - Collision detection method of submersible linear motor - Google Patents

Abstract

The invention discloses a collision detection method of a submersible linear motor, wherein the motion process of the submersible linear motor includes a motion period and a waiting period. The method comprises: obtaining collision information based on current, voltage or power information of the submersible linear motor. According to the detection method provided by the invention, a current sensor arranged at the mouth of a well is used for sampling a current of a linear motor stator in real time without any dependence on a position sensor. A main control board processes the detected stator current and then calculates a collision characteristic quantity; and whether the motor collides is determined based on value taking of the characteristic quantity. Moreover, the provided detection method has advantages of low hardware cost, fast detection speed, and high software universality; and an important means is provided for realizing intelligent control on a linear motor.

Description

Oil immersion line motor collision checking method

Technical field

The invention belongs to oil exploration equipment field, and in particular to a kind of oil immersion line motor collision checking method.

Background technology

During oil extraction in oil field, beam pumping unit is generally adopted, this oil production method will by mechanically operated mode The rotary motion of belt pulley is converted to pumping for sucker rod, so simple structure, reliability height, but there is transmission ring Section loss in efficiency is big, side-abrasion of rod string and the deficiency such as noise is big.

Using the oil pumper of latent oil reciprocating linear electric motor, its motor is cylindrical linear motor, the motor stator Coil is sealed in outer tube, the mover that inner core is made up of permanent magnet, is input into three-phase alternating voltage to stator, you can drive mover Pump.Because the relative machine of kowtowing eliminates rotary motion to the conversion links of linear motion, oil-submersible linear Electric efficiency is improved.

But, due to carrying out install sensor without enough installing spaces in linear electric motors, cause reliability to reduce.In view of latent The typically no position sensor of linear electric machine with oil, linear motor rotor displacement can only realize the open loop control based on synchronous motor characteristic System, therefore rotor position cannot precise control.Leak/take out as down-hole is inevitably present the husky card of linear electric motors, oil well pump The phenomenons such as empty, control error, there is deviation by these factors in the rotor position for causing opened loop control, position deviation is through a timing Between accumulation after, it is more likely that cause electric mover and the stopping means of stator upper and lower ends to collide.Frequently occur so Collision, motor stator outer tube Mechanical Structure Strength will be caused to reduce even damaged, well liquid is entered from breakage and will be led after stator Cause fixed subcoil insulating to reduce even short circuit, reduce electrical machinery life, improve operation expense.

Content of the invention

For the problems referred to above, it is an object of the invention to provide a kind of collision checking method for direct current generator, once Mover is collided with the up/down stopping means of stator, and the method can detect that collision phenomenon occurs at once, be subsequently to take school Positive measure provides important evidence.

Specifically, the invention provides a kind of collision checking method for oil immersion line motor, the oil-submersible linear Motor includes stator and mover, is provided with position limit device and lower caging device on the stator, and the mover is in the upper limit Move back and forth before position device and lower caging device, its motor process includes motion phase and waiting period, it is characterised in that the side Method includes：Collision information is obtained based on the electric current of the oil immersion line motor, voltage or power information.

Further, methods described comprises the steps：

Step (1), the stator current to the oil immersion line motor are sampled；

Step (2), to institute's sample rate current be filtered process；

Step (3), stator input voltages frequency f of the acquisition oil immersion line motor；

Step (4) calculates the oil immersion line motor according to stator input voltages frequency f of the oil immersion line motor The real-time speed v=2 τ f of mover, in formula, v is the mover movement velocity of linear electric motors, and τ is the pole span of linear electric motors；

Step (5), the real-time speed based on the mover for being calculated calculate the displacement of the mover, s=∑ vT_s, public In formula, s is the real-time displacement of the mover, T_sIt is calculating cycle；

Real-time displacement value s of the step (6) based on the calculated mover and setting shift value S_SETIt is compared；

Step (7) is if s >=S_SET, judge that this motor process smoothly terminates, the stator not with position limit device and under Any one in stopping means collides；

Step (8) is if real-time displacement value s<S_SET, assert the motion phase that is currently in, present current value is calculated to the time Rate of change, [i (k)-i (k-1)]/T_s, in formula, i (k) is the stator current value that current sample period is obtained, on i (k-1) is The stator current value that one sampling period obtains, T_sIt is the program interrupt cycle；

Current point is judged to staying for current waveform if the absolute value of slope is less than or equal to predetermined threshold by step (9) Point, to being judged as the point in stationary point, records the current moment, and the moment by the current time for being recorded and a upper adjacent stationary point Value makes the difference the time interval for obtaining two stationary points；

If the absolute value of slope is more than predetermined threshold, step (10) judges that current point is not current waveform stationary point；

Step (11), judge two stationary points time interval whether in 0.4～0.6 times of input voltage periodic regime, such as Fruit time interval in 0.4～0.6 times of input voltage periodic regime, then judge the stator not with position limit device and lower limit Any one in device collides；If time interval is less than 0.4 times of input voltage cycle, judge that the stator is touched Hit；

Step (12), in waiting period, stationary point is recorded clear 0, be next round detection prepare.

Further, the predetermined threshold is 0.05.

The method of the present invention is realized by a control circuit, and which includes 12 pulsating wave autotransformer, the first three-phase bridge Uncontrollable rectifier module REC₁, the second three-phase bridge uncontrollable rectifier module REC₂, the first paralleing reactor L₁, the second paralleing reactor L₂, first, second, third IGBT half-bridge module, first, second, and third output inductor L₃、L₄、L₅, first, second, Three filter capacitor C₁、C₂、C₃,

The 12 pulsating wave autotransformer exports two groups of three-phase alternating voltage A₁B₁C₁And A₂B₂C₂, this two groups of three-phase voltages The phase contrast of corresponding phase is 30 degree, three-phase voltage A₁B₁C₁It is input into the first three-phase bridge uncontrollable rectifier module REC₁, three-phase voltage A₂B₂C₂It is input into the second three-phase bridge uncontrollable rectifier module REC₂, the first three-phase bridge uncontrollable rectifier module REC₁, the second three-phase bridge Formula uncontrollable rectifier module REC₂The positive pole of output is connected respectively to the first paralleing reactor L₁Two-end-point, the first three-phase bridge is not controlled Rectification module REC₁, the second three-phase bridge uncontrollable rectifier module REC₂The negative pole of output is connected respectively to the second paralleing reactor L₂ Two-end-point, the first paralleing reactor L₁Midpoint be connected to dc-link capacitance C_dcPositive pole, the second paralleing reactor L₂In Point is connected to dc-link capacitance C_dcNegative pole to dc-link capacitance C_dcBoth positive and negative polarity connect 3 IGBT half-bridge modules respectively Two ends, the midpoint of three IGBT half-bridge modules passes through first, second, third output inductor L respectively₃、L₄、L₅.

Present applicant is found through experiments, when the mover of motor is collided with stator position-limit mechanism, stator electricity Pressure/electric current can occur obvious distortion, therefore can extract some collision characteristic quantities by the voltage/current for distorting to determine whether Collide.Therefore, the present invention judges collision using motor electronic electric current, implements process as follows：Move the phase in mover Between current Hall sensor real-time sampling motor stator electric current always, the sample rate current of current Hall output completes hardware filtering Core controller (generally DSP, single-chip microcomputer or ARM chip) is sent into after conditioning, core controller enters line number to stator current Wordization is sampled.Judge to be presently at up and down that the operation period is still by whether the current real-time displacement of comparison reaches setting shift value Waiting period, if current real-time displacement is currently at waiting period not less than shift value is set, program does not carry out collision and sentences Disconnected, if current real-time displacement is less than shift value is set, current mover runs the period in up/down, and program is calculated in real time and touched Hit characteristic quantity, collision characteristic quantity can be electric current THD (total harmonic distortion factor), the zero sequence of threephase stator electric current and negative sequence component, Time interval, current changing rate between the adjacent stationary point of electric current short time average, current waveform etc., these collision characteristic quantities are in collision Obvious change can all occur in front and back, therefore can be determined whether by the value of collision characteristic quantity and collide.

It is an advantage of the invention that：1st, hardware cost is low；2nd, detection speed is fast；3. software phase lock loop is good.

Description of the drawings

Fig. 1 is performed for the circuit topology of the switch board of the inventive method；

Fig. 2 is the stator voltage practical measurement of current waveform during operation of linear electric motors normal circulation；

Fig. 3 is measured waveform of the stator voltage electric current before and after colliding；

Fig. 4 is the flow chart of the collision checking method of the present invention.

Specific embodiment

Below in conjunction with accompanying drawing and embodiment, the present invention is described in detail, but not therefore by the protection model of the present invention Enclose and be limited among the scope of embodiment description.

Fig. 1 is performed for the switch board circuit topology of the inventive method.The switch board circuit is taken out for latent oil is reciprocating Oil machine.As shown in figure 1, three-phase alternating current input voltage is input into a 12 pulsating wave autotransformer, the autotransformer output two Group three-phase alternating voltage A₁B₁C₁And A₂B₂C₂, it is 30 degree, i.e. A that this two groups of three-phase voltages correspond to the phase contrast of phase₁、B₁、C₁Phase place Advanced or delayed A₂、B₂、C₂30 degree of phase place.Three-phase voltage A₁B₁C₁Input three-phase bridge uncontrollable rectifier module REC₁, three-phase electricity Pressure A₂B₂C₂Input three-phase bridge uncontrollable rectifier module REC₂, rectification module REC₁And REC₂The positive pole of output is connected respectively to balance Reactor L₁Two-end-point, rectification module REC₁And REC₂The negative pole of output is connected respectively to paralleing reactor L₂Two-end-point.Balance electricity Anti- device L₁Midpoint be connected to dc-link capacitance C_dcPositive pole, paralleing reactor L₂Midpoint be connected to dc-link capacitance C_dc Negative pole.Q₁-Q₂,Q₃-Q₄,Q₅-Q₆For 3 IGBT half-bridge modules, Q₁, Q₃, Q₅For the upper pipe of this 3 half-bridge modules, their collection Electrode is all connected to dc-link capacitance C_dcPositive pole, Q₂, Q₄, Q₆For the down tube of this 3 half-bridge modules, their emitter stage all connects To dc-link capacitance C_dcNegative pole.Q₁, Q₃, Q₅Emitter stage be connected to output inductor L₃, L₄, L₅Input side.3 filtering Electric capacity C₁, C₂, C₃It is connected across filter inductance L₃, L₄, L₅Outlet side.The stator coil of linear electric motors is divided by latent oil armored cable Filter inductance L is not connected to₃, L₄, L₅Outlet side.In switch board, two current Halls are sampled two-way motor electronic electricity respectively Stream, for carrying out collision detection；Master board is while the drive that is input into master board to driving plate, driving plate of output drive signal Dynamic signal exports 6 switching tubes of the 6 road drive signals to 3 half-bridge IGBT module after being processed, the copped wave of driving switch pipe is transported OK.

Fig. 2 is the stator voltage practical measurement of current waveform during operation of linear electric motors normal circulation.Waveform top square frame is general view Figure, bottom square frame is the enlarged drawing of the little square frame in right side in synoptic chart.Maintain two lines inframe in waveform is stator current ripple Shape, what crest exceeded wire frame is stator line voltage waveform.In synoptic chart, voltage current waveform is the sinusoidal period for mover Movement slot, at this moment according to the different phase sequences of stator voltage, mover is run up or down.Voltage current waveform is straight line Period is mover waiting period, and this period, switch board no longer output AC voltage drove mover motion, after the completion of the waiting time, Stator voltage phase sequence is anti-phase, mover commutation operation.In sum, the moving law of linear electric motors is for running downwards-wait-upwards Operation-wait, and with the continuous circular flow of this rule.When can be seen that motor operation from the enlarged drawing of waveform bottom, electric current For good sinusoidal wave form, thus electric current THD is little, and the time interval on current waveform between adjacent stationary point is 1/2 cycle, electric current pair Time rate of change changes in sinusoidal rule.

Fig. 3 is measured waveform of the stator current before and after colliding.What in figure peak value was low is stator current waveforms, peak value High is stator line voltage waveform.Collide with stator position-limit mechanism in the corresponding moment mover of waveform center longitudinal axis, permissible Before seeing that collision occurs, current waveform is in better sinusoidal wave form, and after collision occurs, current waveform occurs substantially to distort, ripple The THD of shape increases, and the absolute value of Current versus time rate of change is significantly increased, and the time interval on current waveform between adjacent stationary point is bright Aobvious reduction.

Fig. 4 is the program flow diagram of collision detection algorithm.This example according in stator current waveforms between adjacent stationary point when Between interval judge whether current waveform is distorted, and then judge whether to collide.Program circuit is as follows：After entrance program, Master control borad sample first stator current and do software filtering remove interference, further according to present input voltage frequency f calculate mover reality Shi Sudu, i.e. v=2 τ f, in formula, v is the mover movement velocity of linear electric motors, and τ is the pole span of linear electric motors, this be one often Amount, f is the frequency of stator voltage, by panel control, is a known quantity.And further calculate mover displacement, i.e. s=∑ vT_s, in formula, s is the real-time displacement of mover, and v is the mover movement velocity of linear electric motors, T_sIt is the program interrupt cycle, is guarantee Computational accuracy, generally musec order.By calculated real-time displacement value s and setting shift value S_SET(shift value is set by electricity The maximum stroke that machine structure is allowed is determined with beam-pumping unit jig frequency, discharge capacity) compare, if s>=S_SET, this motor process is described Smoothly terminate, collision is not sent, in waiting time by clear for stationary point moment value 0, be that next round detection is prepared；If real-time displacement Value s<S_SET, illustrating currently to be in motor process, present current value is at this moment calculated to time rate of change, i.e. [i (k)-i (k- 1)]/T_s, in formula, i (k) is the stator current value that current sample period is obtained, and i (k-1) upper sampling period obtains Stator current value, T_sIt is the program interrupt cycle.If slope is close to 0, such as between -0.05～0.05, illustrate that current point is The stationary point of current waveform, if slope is not in this scope, illustrates that current point is not current waveform stationary point.To being judged as stationary point Point, records the current moment, and makes the difference, with the moment value in a upper adjacent stationary point of record, the time interval for obtaining two stationary points. When not colliding, the time interval is that in 0.5 times of input voltage cycle, after colliding, the interval can greatly reduce.Root The time interval between adjacent stationary point is detected according to this principle, if the time interval is 0.4～0.6 times of input voltage cycle, Illustrate that current waveform does not send distortion, motor is not collided；If the time interval illustrates electricity 0～0.4 times of input voltage cycle Stream waveform is distorted, and motor collides.For improving the reliability of judgement further, repeatedly can be judged, if detection Collide to continuous several times (such as 3 times), that is, judge to collide.

Although above in conjunction with the preferred embodiments of the present invention, the principle of the present invention is described in detail, this area skill Art personnel it should be understood that above-described embodiment is only the explanation to the exemplary implementation of the present invention, not to bag of the present invention Restriction containing scope.All within the spirit and principles in the present invention, according to the technical spirit of the present invention, above example is done Any simple modification, equivalent variations and modification, all still fall within protection scope of the present invention.

Claims (3)

1. a kind of collision checking method for oil immersion line motor, the oil immersion line motor includes stator and mover, described Position limit device and lower caging device is provided with stator, and the mover is gone to the position limit device and lower caging device Multiple motion, its motor process includes motion phase and waiting period, it is characterised in that methods described includes：Based on the oil-submersible linear The electric current of motor, voltage or power information obtain collision information.

2. the collision checking method for oil immersion line motor according to claim 1, it is characterised in that methods described bag Include following step：

Step (1), the stator current to the oil immersion line motor are sampled；

Step (2), to institute's sample rate current be filtered process；

Step (3), stator input voltages frequency f of the acquisition oil immersion line motor；

Step (4) calculates the mover of the oil immersion line motor according to stator input voltages frequency f of the oil immersion line motor Real-time speed v=2 τ f, in formula, v is the mover movement velocity of linear electric motors, and τ is the pole span of linear electric motors；

Step (5), the real-time speed based on the mover for being calculated calculate the displacement of the mover, s=∑ vT_s, in formula, s For the real-time displacement of the mover, T_sIt is calculating cycle；

Real-time displacement value s of the step (6) based on the calculated mover and setting shift value S_SETIt is compared；

Step (7) is if s >=S_SET, judge that this motor process smoothly terminates, the stator not with position limit device and lower limit Any one in device collides；

Step (8) is if real-time displacement value s<S_SET, assert the motion phase that is currently in, present current value is calculated to time change Rate, [i (k)-i (k-1)]/T_s, in formula, i (k) is the stator current value that current sample period is obtained, and i (k-1) is upper one The stator current value that sampling period obtains, T_sIt is the program interrupt cycle；

Step (9), if the absolute value of slope is less than or equal to predetermined threshold, current point is judged to the stationary point of current waveform, right It is judged as the point in stationary point, the current moment is recorded, and the current time for being recorded is done with the moment value in a upper adjacent stationary point Difference obtains the time interval in two stationary points；

If the absolute value of slope is more than predetermined threshold, step (10) judges that current point is not current waveform stationary point；

Step (11), judge two stationary points time interval whether in 0.4～0.6 times of input voltage periodic regime, if when Between be spaced in 0.4～0.6 times of input voltage periodic regime, then judge the stator not with position limit device and lower caging device In any one collide；If time interval is less than 0.4 times of input voltage cycle, judge that the stator collides；

Step (12), in waiting period, stationary point is recorded clear 0, be next round detection prepare.

3. the collision checking method for oil immersion line motor according to claim 2, it is characterised in that the predetermined threshold It is worth for 0.05.