Linear adjustable control method and the device of current impulse trailing edge with rising edge hoisting power
Technical field:
The present invention relates to current impulse production method and device, be specially adapted to current impulse production method and device under the load tool big inductance quantity situation, be applicable to fields such as geophysical exploration, engineer geological prospecting.
Background technology:
In some research and industrial application, need to use forward current pulse, negative current pulse or bipolar current pulse.The reference waveform of bipolar current pulse is characterized in constant amplitude during output current, and electric current is zero during no-output, the current waveform cyclic variation.
Produce the device of current impulse, can produce forward, negative sense or bipolar current pulse, pulse period, adjustable amplitude value.Produce the circuit of bipolar current pulse, realized by full-bridge circuit, four brachium pontis switches adopt all-controlling power electronics device.
Under many circumstances, the load of current impulse device is an inductive load, particularly load is under the big inductance quantity loading conditions such as coil, had a strong impact on the shape of current impulse, current impulse is not desirable impulse waveform, the rising of electric current, decline all have certain time of delay, electric current trailing edge poor linearity.The current impulse device uses as a kind of signal source, to solve adjustable, problems such as trailing edge is linear, rising edge steepness of current impulse fall delay time simultaneously, it is the difficult point in the power electronic technology, it is elongated that the delay of rising edge and trailing edge makes electric current reach time of stable state, influenced the raising of current pulse frequency.
At the current impulse trailing edge, load inductance releases energy and stops electric current to descend, and can produce higher induced voltage, needs to adopt some measure absorption inductor energy.At present, having studied successful similar device at home and abroad often adopts in load series damping resistor, RC network, makes electronic switch in methods such as linear zone work." control circuit of bipolar current pulse generator ", " electronic switch drive circuit ", " reference voltage circuit " adopt prior art.
Summary of the invention:
The object of the present invention is to provide a kind of linear adjustable control method and device of current impulse trailing edge of tool rising edge hoisting power, solve the steepness that promotes the current impulse rising edge, realize the trailing edge linearity, the adjustable problem of turn-off delay time.
In order to realize the foregoing invention purpose, technical scheme of the present invention is:
1, the K that closes a switch, the frequency of regulating " bipolar current pulse control circuit ", the pulse of output periodic current, the cycle of current impulse must be greater than the opening of electronic switch, turn-off delay time sum;
2, regulate the voltage V of dc power supply
1, the amplitude of change output current pulse, the maximum current that current amplitude is passed through less than full control property electronic switch;
3,, make each output cycle produce load voltage waveform V identical shaped, amplitude by control bipolar current pulse generator, DC power supply voltage and clamped voltage source voltage
o(t),
Control voltage, current impulse between forward current pulse rising, decrement phase:
At t
0~t
1During this time, the voltage V that provides to load
o(t
0)=V
2, V
2Greater than DC power supply voltage V
1, the current impulse fast rise, booster tension realizes that with promoting electric capacity in the electric current uphill process, capacitive energy discharges, V
o(t) descend, after after a while, V
o(t
1)=V
1
At t
1~t
2During this time, V
o(t
1)=V
1, current impulse continues to rise, but slows down;
At t
2~t
3During this time, V
o(t) by just becoming negative value, V
o(t
2The V of)=-
3, current impulse begins to descend, at t
3Current attenuation constantly arrives zero, during this period, and V
o(t) keep stable, current impulse is linear and descends;
Negative current pulse rising, the control voltage of decline process, current impulse:
At t
3~t
4During this time: V
o(t)=0;
At t
4~t
5During this time: the voltage V that provides to load
o(t
4The V of)=-
2, negative current pulse fast rise, booster tension realizes that with electric capacity in the negative current uphill process, capacitive energy discharges, V
o(t) amplitude reduces, after after a while, and V
o(t
5The V of)=-
1
At t
5~t
6During this time: V
o(t)=-V
1, the negative current pulse continues to rise, but slows down;
At t
6~t
7During this time: V
o(t) become on the occasion of, V by negative value
o(t
6)=V
3, the negative current pulse begins to descend, at t
7Current attenuation constantly arrives zero, during this period, and V
o(t) keep stable, the negative current pulse is linear and descends;
Wherein:
t
0: the zero hour of output forward current pulse, t
1: V
o(t) drop to V
1The moment,
t
2: the moment that the forward current pulse begins to descend, t
3: the forward current pulse drops to for zero the moment,
t
4: the zero hour of output negative current pulse, t
5: V
o(t) by-V
2Be reduced to-V
1The moment,
t
6: the moment that the negative current pulse begins to descend, t
7: the negative current pulse drops to for zero the moment,
V
2: booster tension;
4, calculate positive and negative current impulse descending slope:
The positive current pulses descending slope:
The negative current pulse descending slope:
K
2=-K
1
Wherein:
R
L: the load dc resistance;
L: load inductance amount;
V
3: clamped voltage source voltage;
Work as V
3>>R
LI
0The time,
Load current is linear to descend, because positive current pulses and the load voltage absolute value of negative current pulse between decrement phase equate that therefore, the descending slope of positive current pulses and negative current pulse is identical.
Wherein: I
0Be current pulse amplitude, also equal the initial value of current impulse trailing edge.
Linearity formula:
Wherein, I
0: the initial value of current impulse trailing edge;
Δ I
Max: current impulse decline curve and best-fitting straight line worst error.
5, calculate the output current pulse delay fall time (unit: μ s):
Wherein, I
0: the current value when current impulse begins to descend;
By changing V
3, scalable current impulse fall delay time t
d, improve V
3, shortened the current impulse fall delay time, V
3Be arranged on 0 between the electronic switch rated insulation voltage.
The inventive system comprises DC power supply, mains switch, bipolar current pulse generator and control circuit thereof, the inductive load that the output of this bipolar current pulse generator connects; The input that rising edge promotes circuit is connected with DC power supply, the output that this rising edge promotes circuit is connected with the input of bipolar current pulse generator, the energy feed side that rising edge promotes circuit is connected with the output of clamped voltage source, the input of clamped circuit is connected with inductive load, and the output of clamped circuit is connected with the input of clamped voltage source.
DC power supply is through switch k, be connected to " bipolar current pulse generator " input through " rising edge lifting circuit ", " bipolar current pulse generator " output connects load, be connected to " clamped voltage source " after the load parallel connection " clamped circuit ", " clamped voltage source " output is connected to " rising edge lifting circuit ", " bipolar current pulse control circuit " is connected to " bipolar current pulse generator ", and " control circuit of bipolar current pulse generator " is made of " frequency adjustment ", " control timing generation circuit ", " drive circuit ".Power switch in " bipolar current pulse generator " and " clamped voltage source " adopts the full-control type electronic switch.At t
2~t
3, t
6~t
7During this time, realize clamped to load voltage by " clamped voltage source " and " clamped circuit ", load energy is absorbed by " clamped voltage source ", and excess energy is transferred to " rising edge lifting circuit ", reach the purpose of voltage stabilizing, the load voltage amplitude is V during trailing edge
3
" clamped voltage source " intake is the load inductance energy, outputs to " rising edge lifting circuit ", and flowing of energy is unidirectional.The current impulse rising edge divides two stages, t
0~t
1Load voltage is by " rising edge lifting circuit " decision, V afterwards during this time
o(t)=V
1During " bipolar current pulse generator " stops to export energy, load voltage is by clamped " clamped voltage source " voltage that arrives, " clamped voltage source " excess energy is transferred to " rising edge lifting circuit ", " clamped voltage source " voltage is stable, make load voltage constant amplitude between the current impulse decrement phase, realized the voltage stabilizing control of the load voltage between the current impulse decrement phase." rising edge lifting circuit " energy storage device is made of electric capacity, and " clamped voltage source " releases energy in " rising edge lifting circuit ", is promoting circuit generation higher voltage V
2, be t
0~t
1, t
4~t
5The fast rise of current impulse during this time creates conditions.
The present invention compared with prior art has following technique effect:
1, realized the short time delay of current impulse, made the rising edge steepening of current impulse.
When current impulse descends, the excess energy of " clamped voltage source " storage is transferred to capacitor C
2In, C
2Voltage be higher than DC power supply voltage, when " bipolar current pulse generator " output current, capacitor C
2The energy rapid release has promoted the current impulse rate of climb, makes the rising edge steepening.
2, between the current impulse decrement phase, control inductive load voltage is stable, realizes current impulse trailing edge linearity.
3, regulate " clamped voltage source " voltage setting value, make current impulse fall delay time t
dAdjustable.
Measured data:
Emission current 57A, V
1=38V, coil resistance 0.5 Ω, winding inductance quantity 1.9mH, the capacitance voltage set point is 600V, electronic switch adopts the IGBT module of 1200V, 100A, downslope time 166us.
Description of drawings:
Fig. 1 is the interior load voltage waveform figure and the load current waveform figure of one-period of the linear adjustable control method of a kind of current impulse steepness;
Fig. 2 is the composition frame chart of device of the present invention;
Fig. 3 is-kind of circuit topology figure of the composition frame chart of device of the present invention.
Fig. 4 is second kind of circuit topology figure of the composition frame chart of device of the present invention;
Fig. 5 is actual measurement emission current oscillogram: emission current 57A, V
1=38V, coil resistance 0.5 Ω, winding inductance quantity 1.9mH, the capacitance voltage set point is 600V, electronic switch adopts the IGBT module of 1200V, 100A;
Fig. 6 is actual measurement emission current trailing edge oscillogram 2: emission current 57A, V
1=38V, coil resistance 0.5 Ω, winding inductance quantity 1.9mH, the capacitance voltage set point is 600V, electronic switch adopts the IGBT module of 1200V, 100A, downslope time 166us;
Fig. 7 is actual measurement emission current rising edge oscillogram: emission current 57A, V
1=38V, coil resistance 0.5 Ω, winding inductance quantity 1.9mH, the capacitance voltage set point is 600V, electronic switch adopts the IGBT module CM 100DU-24NFH of 1200V, 100A, current rise time 204us;
Fig. 8 is actual measurement V
3Oscillogram;
Fig. 9 is actual measurement V
o(t) oscillogram;
Figure 10 is actual measurement load both end voltage V
o(t) the local waveform amplification figure during trailing edge;
Figure 11 promotes capacitor C for actual measurement
2Oscillogram.
In Fig. 1:
t
0: the zero hour of output forward current pulse, t
1: V
o(t) drop to V
1The moment,
t
2: the moment that the forward current pulse begins to descend, t
3: the forward current pulse drops to for zero the moment,
t
4: the zero hour of output negative current pulse, t
5: V
o(t) by-V
2Drop to-V
1The moment,
t
6: the moment that the negative current pulse begins to descend, t
7: the negative current pulse drops to for zero the moment,
V
1: DC power supply voltage, V
2: booster tension,
V
3Clamped voltage source voltage, V
o(t): load voltage waveform,
I
o(t): current pulse shape, t
d: the current impulse fall delay time.
In Fig. 2:
I
o(t), V
o(t), V
1, V
3With I among Fig. 1
o(t), V
o(t), V
1, V
3Identical, frame of broken lines is represented the control circuit of bipolar current pulse generator among the figure.
In Fig. 3:
The 1-rising edge promotes circuit,
2-bipolar current pulse generator and control circuit thereof,
The clamped circuit of 3-,
Clamped voltage source.
Embodiment:
Concrete control method of the present invention is:
1, the K that closes a switch, the frequency of regulating " bipolar current pulse control circuit " is 12.5Hz
2, regulate the voltage V of dc power supply
1=38V, the output current pulse amplitude is 57A, the maximum current that the full control electronic switch of selecting for use passes through is 100A;
3, the periodic load voltage waveform V of output
o(t) be:
t
0: V
o=V
2, V
1<V
2<V
3, be V among the figure
o=550V;
t
1:V
o=38V;
t
2: V
oReduce to-600V by 38V;
t
3: V
oRise to 0V by-600V;
t
4: V
oReduce to-550V by 0V;
t
5:V
o=-38V;
t
6: V
oRise to 600V by-38V;
t
7: V
oReduce to 0V by 600V;
Control voltage, current impulse between forward current pulse rising, decrement phase:
At t
0~t
1During this time, the voltage V that provides to load
o(t) initial value V
o(t
0)=V
2=550V, current impulse is risen, and speed is fast.Booster tension is realized with electric capacity, promotes electric capacity at t
0The time voltage be V
2, in the electric current uphill process, capacitive energy discharges, V
o(t) descend, after after a while, V
o(t
1)=V
1
At t
1~t
2During this time, V
o(t) equal V
1, being 38V, current impulse continues to rise, but slows down;
At t
2~t
3During this time, V
o(t) by just becoming negative value, V
o(t
2The V of)=-
3=-600V, current pulse amplitude descends, at t
3Current attenuation constantly is to zero.During this period, V
o(t) keep stable, therefore, current impulse is linear and descends.
Negative current pulse rising, the control voltage of decline process, current impulse:
At t
3~t
4During this time: V
o(t)=0;
At t
4~t
5During this time: V
o(t
4The V of)=-
2, negative current appears in load, and the electric current rate of climb is fast.Booster tension is realized with electric capacity.In the electric current uphill process, capacitive energy discharges, V
o(t) amplitude descends, after after a while, and V
o(t
5The V of)=-
1
At t
5~t
6During this time: V
o(t
5The V of)=-
1, the negative current pulse continues to rise, but slows down;
At t
6~t
7During this time: V
o(t
6)=V
3, the negative current pulse begins to descend, at t
7Current attenuation constantly is to zero.During this period, V
o(t) keep stable, therefore, the negative current pulse is linear and descends.
4, calculate positive and negative current impulse descending slope:
The positive current pulses descending slope:
The negative current pulse descending slope:
K
2=-K
1=3.15×10
5
Wherein: L=1.9mH, V
3=600V
Linearity formula:
Wherein: I
0=57A, Δ I
Max=0.22A
5, calculate the output current pulse delay fall time (unit: μ s):
Wherein, I
0=57A, R
L=0.5 Ω, L=1.9mH, V
3=600V.
By changing V
3, scalable current impulse fall delay time t
d, improve V
3, shortened the current impulse fall delay time.V
3Be arranged on 0 between the electronic switch rated insulation voltage.
In Fig. 3:
Rising edge promotes circuit and comprises diode D
1, D
2And capacitor C
2, diode D
1Positive pole connect DC power supply switch, diode D
1Negative pole meet diode D
2Positive pole, two diode D
2Negative pole meet diode D in the bipolar current pulse generator
5, D
7Negative pole, capacitor C
2Two ends meet diode D respectively
2Positive pole and the negative pole of DC power supply.
Clamped circuit comprises diode D
3, D
4, diode D
3, D
4Negative pole connects, diode D
3, D
4Positive pole is connected with the two ends of inductive load respectively.
Clamped voltage source comprises capacitor C
1, resistance R
1, R
2, R
3, R
4, full-control type electronic switch J
5, operational amplifier, electronic switch drive circuit, reference voltage circuit, capacitor C
1Two ends connect diode D respectively
3, D
4Negative pole, full-control type electronic switch J
5With the negative pole of DC power supply, resistance R
1Two ends connect diode D respectively
1Negative pole and full-control type electronic switch J
5, resistance R
3, R
4An end connect the in-phase end of operational amplifier, resistance R after connecting
3, R
4The other end meet the negative pole and the full-control type electronic switch J of DC power supply respectively
5, resistance R
2Two ends connect the output of operational amplifier and the in-phase end of this operational amplifier, full-control type electronic switch J respectively
5Connect the electronic switch drive circuit, the output of operational amplifier, end of oppisite phase connect electronic switch drive circuit and reference voltage circuit respectively.
In Fig. 4:
Rising edge promotes circuit and comprises diode D
1, D
2And capacitor C
2, diode D
1Negative pole connect the negative pole of DC power supply, diode D
1Positive pole meet diode D
2Negative pole, diode D
2Positive pole meet diode D in the bipolar current pulse generator
6, D
8Positive pole, capacitor C
2Two ends meet diode D respectively
2Negative pole, resistance R
1With the diode D in the bipolar current pulse generator
5, D
7Negative pole.
Clamped circuit comprises diode D
3, D
4, diode D
3, D
4Anodal connection, diode D
3, D
4Negative pole is connected with the two ends of inductive load respectively.
Clamped voltage source comprises capacitor C
1, resistance R
1, R
2, R
3, R
4, full-control type electronic switch J
5, operational amplifier, electronic switch drive circuit, reference voltage circuit, capacitor C
1Two ends connect diode D in clamped circuit and the bipolar current pulse generator respectively
5, D
7Negative pole, resistance R
1Two ends connect diode D respectively
2Negative pole and full-control type electronic switch J
5, full-control type electronic switch J
5Connect clamped circuit and electronic switch drive circuit, resistance R
3, R
4An end connect the in-phase end of operational amplifier, resistance R after connecting
3, R
4The other end connect clamped circuit and mains switch, resistance R respectively
2Two ends connect the output and the in-phase end of operational amplifier, the output termination electronic switch drive circuit of operational amplifier, the anti-phase termination reference voltage circuit of operational amplifier respectively.
In Fig. 3, Fig. 4, resistance R
1Available inductance replaces.
In Fig. 3, Fig. 4, capacitor C
2Choosing of appearance value:
E
Max: the supply power voltage maximum;
U
J: the minimum value of the rated insulation voltage value of electronic switch;
The load inductance energy is transferred to C through " clamped circuit "
1In, C
1Terminal voltage is through resistance R
3, R
4Be connected to the comparator in-phase end after the dividing potential drop, " reference voltage circuit " is connected to the comparator end of oppisite phase.Work as capacitor C
1Voltage V
3When being higher than setting voltage, comparator output signal is by " electronic switch drive circuit " control electronic switch J
5Conducting, capacitor C
1Portion of energy is transferred to " rising edge lifting circuit ", and portion of energy is by resistance R
1Consume; Work as capacitor C
1Voltage V
3When being lower than setting voltage, comparator output signal control J
5End capacitor C
1Energy is stored.By control J
5Conducting, make capacitor C
1Voltage V
3Stable.Capacitor C
1The comparison of both end voltage and setting voltage is realized than circuit by stagnant chain rate.
By regulating " voltage setting " reference voltage, realize V
3Adjustable.
By selecting suitable " rising edge lifting circuit " capacitor C
2Capacitance makes C
2The voltage that voltage is released when finishing in load energy is enough high, in electronic switch rated insulation voltage scope, can reduce resistance R again
1The energy that consumes improves the lifting effect of current impulse rising edge.
Resistance R
1Choose:
I
Max: the emission current maximum;
V
3max: the maximum that " clamped voltage source " voltage is set;
V
1min: " direct voltage source " voltage minimum.