CN104767290A - Induction type wireless power supply system double-closed-loop constant output current control method - Google Patents
Induction type wireless power supply system double-closed-loop constant output current control method Download PDFInfo
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Abstract
Provided is an induction type wireless power supply system double-closed-loop constant output current control method. The method comprises outer-loop controlling and inner-loop controlling. The outer-loop controlling comprises the steps that based on a short time fourier transformation method, real-time processing is carried out on output voltage and output current signals of a primary side high-frequency inverter, an equivalent impedance of a resonance circuit is calculated, it is judged whether an impedance phase-angle is in a threshold value range or not, if the impedance phase-angle exceeds a threshold value, an automatic frequency adjusting module is started, calculation is repeated, and the equivalent impedance of the primary side resonance circuit is judged until a system works in a resonance state. The inner-loop control comprises the steps that an input voltage theoretical value of the high-frequency inverter is calculated and corrected, and is used as an input voltage reference value of the inner-loop controlling. According to deviation of the input voltage reference value and a measuring value (actual input voltage of the high-frequency inverter), real-time calculation is carried out, a duty ratio of a switch signal of the deviation is removed, and a corresponding switch pulse signal is output. According to double-closed-loop constant output current controlling, energy output of an induction type wireless power supply system can be effectively controlled, and the wireless electric energy transmission quality is improved.
Description
Technical field
The present invention relates to a kind of induction type wireless power supply system two close cycles constant output current control method.
Background technology
Induction type wireless power transmission technology is a kind of based on electromagnetic field near field principle of induction, comprehensive utilization Technics of Power Electronic Conversion technology, magnetic Field Coupling technology and control theory, realizes power consumption equipment obtains energy from electrical network technology in non-conductive contact mode.Its general principle utilizes controlled resonant converter to be high-frequency alternating current by industrial-frequency alternating current or DC power conversion, Implantation Energy trigger mechanism (such as coil), in conjunction with inspiring the high-frequency alternating magnetic field with same frequency in space based on electromagnetic induction principle, make to induce high-frequency electrical kinetic potential in the pick-up winding of the energy acceptance mechanism be in this magnetic field, finally by directly exporting to after Technics of Power Electronic Conversion by electric loading, thus realize the wireless transmission of electric energy.
For transmitting enough energy with the normal operation of proof load to energy pickup end, energy transmitter structure needs to maintain larger excitatory magnetic field intensity, is generally to realize by controlling the method that in transmitting coil, exciting curent is constant.Therefore, the mode accessing Buck DC converter before high-frequency inverter is induction type radio energy transmission system current constant control strategy conventional at present, under this current constant control strategy, controller is according to the deviation between exciting curent reference value and measured value, calculate the duty ratio of Buck DC converter switching signal, by regulating the current constant control of size (i.e. the input voltage of induction type radio energy transmission system) realization to exciting curent of Buck DC converter output voltage, in fact the current constant control effect of this induction type radio energy transmission system depends on the control precision of Buck DC converter.
But, due to the problem of parameter choose, certain deviation is usually there is in the output voltage (product of input voltage and switching signal duty ratio) that Buck DC converter is expected with actual output voltage, cause the increase of current constant control process overshoot and the growth of regulating time, introduce serious input voltage fluctuation also likely to induction type radio energy transmission system, affect the delivery of electrical energy quality of whole system.Therefore, in order to make induction type radio energy transmission system obtain good current constant control effect, be necessary to measure the output voltage of Buck DC converter further and control.
Summary of the invention
The object of this invention is to provide a kind of induction type wireless power supply system two close cycles constant output current control method, the method can realize the current constant control to induction type wireless power supply system exciting curent more quickly and accurately, effectively reduce the input voltage fluctuation of induction type wireless power supply system, improve wireless power transmission quality.
It is that a kind of induction type wireless power supply system two close cycles constant output current control method, the steps include: that the present invention realizes the technical scheme that its goal of the invention adopts
A, outer shroud control:
A1, outer ring controller produce switching signal according to current switch operating frequency, control the output voltage frequency of high-frequency inverter;
High-frequency inverter output voltage signal, output current signal that A2, output voltage sensor, output current transducer will detect, carry out after signal amplification, filtering, analog-to-digital conversion through signal processing unit, obtain the output voltage numeral signal of high-frequency inverter, output current numeral signal, send outer ring controller;
Output voltage numeral signal, output current numeral signal that A3, outer ring controller are sent here signal processing unit, application Short Time Fourier Transform calculates the fundametal compoment of output voltage numeral signal
the fundametal compoment of output current numeral signal
A4, outer ring controller calculate the equiva lent impedance of former limit resonant circuit
equiva lent impedance
amplitude be Z
p, phase angle is θ
p;
If phase angle theta
pabsolute value | θ
p| be greater than phase angle threshold value θ
h, then outer ring controller, regulates current switch operating frequency, turns A1 step;
If phase angle theta
pabsolute value | θ
p| be less than phase angle threshold value θ
h, carry out the operation of following A5 step;
A5, outer ring controller are by the fundametal compoment of the output current of high-frequency inverter numeral signal
with the former limit resonance current reference value I preset
pcompare, obtain deviate e
i,
and calculate this deviate e of elimination
icorresponding high-frequency inverter input voltage variation delta u;
B, inner ring control:
The high-frequency inverter input voltage variation delta u that B1, interior ring controller obtain in being walked by A5 and high-frequency inverter input voltage theoretical value u
0be added, as the high-frequency inverter input voltage reference value V that inner ring controls
ref, V
ref=u
0+ Δ u;
B2, high-frequency inverter input have access to Buck DC converter, and the voltage of input voltage sensor detection Buck DC converter output obtains the input voltage V of high-frequency inverter
dC; And by the input voltage V of high-frequency inverter
dCsend signal processing unit to carry out amplifying, filtering, after AD conversion, then ring controller in sending into;
B1 is walked the voltage reference value V obtained by B3, interior ring controller
refwith the input voltage V of the high-frequency inverter recorded in B2 step
dCsubtract each other, obtain input deviation value e
v, e
v=V
ref-V
dC, and calculate this input deviation of elimination value e
vbuck DC converter Duty ratio control amount D;
The duty ratio of B4, interior ring controller control Buck DC converter is Duty ratio control amount D.
Compared with prior art, the invention has the beneficial effects as follows:
One, the A1-A4 step that outer shroud controls can ensure that high-frequency inverter output impedance becomes purely resistive, namely inverter is operated in resonance condition, effectively reduce the reactive loss of system, EMI interference, make the output current of energy trigger mechanism have good sine-wave oscillation characteristic, improve delivery of electrical energy quality; On this basis, according to the deviation of former limit resonance current reference value and measured value fundametal compoment, the high-frequency inverter input voltage variable quantity of this deviation that is eliminated, for rapidity, the accuracy realizing current constant control provides advantage;
Two, interior ring controller is by calculating high-frequency inverter input voltage theoretical value corresponding to former limit resonance current reference value (output current of expectation), and after it is corrected, form the reference voltage level of inner ring control, controlled volume using the output voltage of Buck DC converter as inner ring input voltage, according to the deviation between its voltage reference value and measured value, the duty ratio of by-pass cock signal, ensure that the steady of Buck DC converter output voltage, thus can be quicker, realize the current constant control to induction type radio energy transmission system exciting curent exactly, effectively reduce the input voltage fluctuation of induction type radio energy transmission system, improve wireless power transmission quality.
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Accompanying drawing explanation
Fig. 1 is the control flow schematic diagram of the embodiment of the present invention.
Fig. 2 is the two close cycles constant output current control effects figure of the embodiment of the present invention.
Embodiment
Embodiment
Fig. 1 illustrates, a kind of embodiment of the present invention is, a kind of double closed loop constant current control method of voltage-type induction type wireless power supply system, the steps include:
A, outer shroud control:
A1, outer ring controller 1 produce switching signal according to current switch operating frequency, control the output voltage frequency of high-frequency inverter 2;
High-frequency inverter 2 output voltage signal, output current signal that A2, output voltage sensor 3a, output current transducer 3b will detect, after signal processing unit 4 carries out signal amplification, filtering, analog-to-digital conversion, obtain the output voltage numeral signal of high-frequency inverter 2, output current numeral signal, send outer ring controller 1;
Output voltage numeral signal, output current numeral signal that A3, outer ring controller 1 pair of signal processing unit 4 are sent here, application Short Time Fourier Transform calculates the fundametal compoment of output voltage numeral signal
the fundametal compoment of output current numeral signal
A4, outer ring controller 1 calculate the equiva lent impedance of former limit resonant circuit
equiva lent impedance
amplitude be Z
p, phase angle is θ
p;
If phase angle theta
pabsolute value | θ
p| be greater than phase angle threshold value θ
h, then outer ring controller 1, regulates current switch operating frequency, turns A1 step;
If phase angle theta
pabsolute value | θ
p| be less than phase angle threshold value θ
h, carry out the operation of following A5 step;
A5, outer ring controller 1 are by the fundametal compoment of the output current of high-frequency inverter 2 numeral signal
with the former limit resonance current reference value I preset
pcompare, obtain deviate e
i,
and calculate this deviate e of elimination
icorresponding high-frequency inverter 2 input voltage variation delta u;
B, inner ring control:
The high-frequency inverter 2 input voltage variation delta u that B1, interior ring controller 1 obtain in being walked by A5 and high-frequency inverter 2 input voltage theoretical value u
0be added, as the high-frequency inverter 2 input voltage reference value V that inner ring controls
ref, V
ref=u
0+ Δ u;
B2, high-frequency inverter 2 input have access to Buck DC converter 5, and the voltage of input voltage sensor 5a detection Buck DC converter 5 output obtains the input voltage V of high-frequency inverter 2
dC; And by the input voltage V of high-frequency inverter 2
dCsend signal processing unit 4 to carry out amplifying, filtering, after AD conversion, then ring controller 6 in sending into;
B1 is walked the voltage reference value V obtained by B3, interior ring controller 6
refwith the input voltage V of the high-frequency inverter 2 recorded in B2 step
dCsubtract each other, obtain input deviation value e
v, e
v=V
ref-V
dC, and calculate this input deviation of elimination value e
vbuck DC converter 5 Duty ratio control amount D;
The duty ratio of B4, interior ring controller 6 control Buck DC converter 5 is Duty ratio control amount D.
In the present embodiment, A3 walks the Short-Time Fourier Transform adopted, namely be that the output voltage signal of N number of high-frequency inverter sampled point and output current signal are processed, and calculate the fundametal compoment of corresponding output voltage signal and output current signal according to formula (1) and formula (2):
Wherein, u
p[n] is the output voltage signal that the n-th sampled point obtains high-frequency inverter, i
p[n] is the output current signal of the high-frequency inverter that the n-th sampled point obtains.Because the fundametal compoment of output voltage signal and output current signal is plural form, therefore, the equiva lent impedance of the present embodiment A4 step limit, Central Plains resonant circuit can be counted:
In the A5 step of the present embodiment, the theoretical value of simple proportional algorithm to high-frequency inverter input voltage is selected to correct, to eliminate exciting curent deviation, namely
Δu＝K
P1e
i(4)
In the present embodiment, K
p1=1 × 10
-9.
In the B1 step of the present embodiment, input voltage theoretical value u
0with the former limit resonance current reference value I preset
prelation u
0=f (I
p) can be expressed as:
Wherein, Z
pand Z
sbe respectively the equiva lent impedance size of former limit resonant circuit and high-frequency inversion link switching device.
In B3 step, the duty ratio of Buck DC converter switching signal can adopt formula (6) to calculate, wherein V
infor known Buck DC converter input voltage.
D＝K
P2e
v+V
ref/V
in(6)
In the present embodiment, K
p2=0.01.
Fig. 2 has shown the double closed loop constant current control effect of voltage-type induction type wireless power supply system.The operating state of system adopts following setting: t
1in the moment, system starts; t
2moment, load variations; t
3in the moment, constant current value changes.As can be seen from the figure, t
1-t
3in the stage, when high-frequency inverter output current reference value requires identical, the resonant operational frequency of system and the output voltage of Buck DC converter all change along with the change of former limit resonant circuit equiva lent impedance; t
2-t
4stage, when former limit resonant circuit equiva lent impedance is identical, the change only having the output voltage of Buck DC converter to require along with high-frequency inverter output current reference value and changing.Under the double closed loop constant current control strategy that the present invention proposes, high-frequency inverter output current not only has good sine-wave oscillation characteristic, its effective value also can be stabilized in the reference value of requirement quickly and accurately, the output voltage of Buck DC converter has good steady equally, effectively prevent the input voltage fluctuation of voltage-type induction type wireless power supply system, ensure that delivery of electrical energy quality.
Claims (1)
1. an induction type wireless power supply system two close cycles constant output current control method, the steps include:
A, outer shroud control:
A1, outer ring controller (1) produce switching signal according to current switch operating frequency, control the output voltage frequency of high-frequency inverter (2);
High-frequency inverter (2) output voltage signal, output current signal that A2, output voltage sensor (3a), output current transducer (3b) will detect, after signal processing unit (4) carries out signal amplification, filtering, analog-to-digital conversion, obtain the output voltage numeral signal of high-frequency inverter (2), output current numeral signal, send outer ring controller (1);
Output voltage numeral signal, output current numeral signal that A3, outer ring controller (1) are sent here signal processing unit (4), application Short Time Fourier Transform calculates the fundametal compoment of output voltage numeral signal
the fundametal compoment of output current numeral signal
A4, outer ring controller (1) calculate the equiva lent impedance of former limit resonant circuit
equiva lent impedance
amplitude be Z
p, phase angle is θ
p;
If phase angle theta
pabsolute value | θ
p| be greater than phase angle threshold value θ
h, then outer ring controller (1), regulates current switch operating frequency, turns A1 step;
If phase angle theta
pabsolute value | θ
p| be less than phase angle threshold value θ
h, carry out the operation of following A5 step;
A5, outer ring controller (1) are by the fundametal compoment of the output current of high-frequency inverter (2) numeral signal
with the former limit resonance current reference value I preset
pcompare, obtain deviate e
i,
and calculate this deviate e of elimination
icorresponding high-frequency inverter (2) input voltage variation delta u;
B, inner ring control:
High-frequency inverter (2) the input voltage variation delta u that B1, interior ring controller (1) obtain in being walked by A5 and high-frequency inverter (2) input voltage theoretical value u
0be added, as high-frequency inverter (2) the input voltage reference value V that inner ring controls
ref, V
ref=u
0+ Δ u;
B2, high-frequency inverter (2) input have access to Buck DC converter (5), and the voltage that input voltage sensor (5a) detects Buck DC converter (5) output obtains the input voltage V of high-frequency inverter (2)
dC; And by the input voltage V of high-frequency inverter (2)
dCsend signal processing unit (4) to carry out amplifying, filtering, after AD conversion, then ring controller (6) in sending into;
B1 is walked the voltage reference value V obtained by B3, interior ring controller (6)
refwith the input voltage V of the high-frequency inverter (2) recorded in B2 step
dCsubtract each other, obtain input deviation value e
υ, e
υ=V
ref-V
dC, and calculate this input deviation of elimination value e
υbuck DC converter (5) Duty ratio control amount D;
The duty ratio of B4, interior ring controller (6) control Buck DC converter (5) is Duty ratio control amount D.
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| CN110126648A (en) * | 2019-04-25 | 2019-08-16 | 西安理工大学 | The tracking of electric car wireless charging maximum current from optimizing tuning control method |
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| CN114740272A (en) * | 2022-04-18 | 2022-07-12 | 西南交通大学 | Bus capacitance online monitoring method, device, equipment and storage medium |
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