CN116247831A - Concrete-air cross-medium wireless power transmission system and control method thereof - Google Patents
Concrete-air cross-medium wireless power transmission system and control method thereof Download PDFInfo
- Publication number
- CN116247831A CN116247831A CN202310196561.2A CN202310196561A CN116247831A CN 116247831 A CN116247831 A CN 116247831A CN 202310196561 A CN202310196561 A CN 202310196561A CN 116247831 A CN116247831 A CN 116247831A
- Authority
- CN
- China
- Prior art keywords
- concrete
- capacitance
- conduction angle
- wireless power
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims abstract description 23
- 239000003990 capacitor Substances 0.000 claims abstract description 50
- 238000004364 calculation method Methods 0.000 claims description 25
- 230000003071 parasitic effect Effects 0.000 claims description 23
- 238000004804 winding Methods 0.000 claims description 19
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 238000001514 detection method Methods 0.000 claims description 12
- 230000008859 change Effects 0.000 claims description 8
- 238000012546 transfer Methods 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 6
- 239000004020 conductor Substances 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 238000013461 design Methods 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 14
- 239000002131 composite material Substances 0.000 description 12
- 230000000694 effects Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 238000011217 control strategy Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000036541 health Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 230000003090 exacerbative effect Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000007847 structural defect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
- H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Inverter Devices (AREA)
Abstract
The invention relates to the technical field of wireless power transmission, in particular to a concrete-air cross-medium wireless power transmission system and a control method thereof, wherein a receiving coil of the concrete-air cross-medium wireless power transmission system is arranged in concrete, a transmitting coil is arranged in air, and a variable capacitor is added into a primary circuit through designing an adjustable capacitor module so as to adjust the primary natural resonant frequency according to a disturbance observation method, so that both a primary side and a secondary side work in a resonant state, and the system keeps higher transmission efficiency; the invention also designs the frequency modulation tuning module to control the phase of the output voltage of the inverter to be consistent with the phase of the primary side current, so that the primary side circuit and the secondary side circuit of the WPT system are both resonant, the output power and the efficiency of the WPT system are improved, the higher output power and the higher efficiency can be still maintained when the concrete medium changes (such as humidity changes and temperature changes), and the electric equipment in the concrete can be charged stably, reliably and efficiently.
Description
Technical Field
The invention relates to the technical field of wireless power transmission, in particular to a concrete-air cross-medium wireless power transmission system and a control method of the concrete-air cross-medium wireless power transmission system.
Background
Environmental factors (wind, temperature, rain, earthquake, etc.) can continuously cause damage to concrete buildings such as bridges, tunnels, buildings, etc., and shorten the service life of the buildings. In order to conduct targeted maintenance on a building having structural defects, damage data inside the building, particularly the water content, corrosion degree, etc. inside the building must be acquired. At the beginning of the 90 s of the 20 th century, a number of important large span bridges were fitted with structural health monitoring (Structural Health Monitoring, SHM) systems, which not only monitored the changes in bridge structure, but also the environmental impact on the bridge. Conventional structural monitoring systems rely on wired sensors, but wired sensors are complex in circuitry and long-term exposure to the harsh external environment can result in cable damage that can affect sensor reliability. More critical is that cables embedded in the bridge can accelerate the water seepage inside the bridge, exacerbating the corrosion inside the bridge. In contrast, embedded wireless sensors are more suitable for use in SHM systems. The lithium polymer battery power supply adopted by the wireless sensor at present is extremely easy to be limited by battery capacity and weight, and research on a new power supply mode becomes an urgent need of the current society.
The wireless power transmission system can carry out high-efficiency energy transmission through the coupling between the resonant coils only when the transmitting coil and the receiving coil are resonant, and the output power and the efficiency are high at the moment, but in an actual concrete-air cross-medium WPT system, the natural resonant frequencies of the transmitting coil and the receiving coil are changed due to the influence of the electromagnetic parameters of concrete, so that the output power is greatly fluctuated, and the efficiency of the whole system is reduced.
Disclosure of Invention
The invention provides a concrete-air cross-medium wireless power transmission system and a control method thereof, which solve the technical problems that: the wireless power transmission system designed by a single medium is used in a concrete-air cross-medium environment, so that the system deviates from the resonant frequency, the output power and the efficiency of the system are greatly reduced, and the system is difficult to stably and efficiently supply power.
In order to solve the technical problems, the invention provides a concrete-air cross-medium wireless power transmission system which comprises a direct current power supply, an inverter and a primary side series resonance capacitor C which are sequentially connected P Transmitting coil L P And sequentially connected receiving coils L S Secondary side series resonance capacitor C S Equivalent load R L The key point is that:
the receiving coil L S Is installed in concrete, and the transmitting coil L P Is installed in the air;
the system also comprises an adjustable capacitance module, wherein the adjustable capacitance module comprises an efficiency calculation unit, a capacitance conduction angle calculation unit and an adjustable capacitance circuit, and the adjustable capacitance circuit is connected in series with the primary side series resonance capacitor C P With the transmitting coil L P Between them; the efficiency calculation unit is used for calculating the input power and the output power of the system and calculating the efficiency of the system; the capacitance conduction angle calculation unit is used for calculating the conduction angle alpha of the switching tube according to the system efficiency and acting on the adjustable capacitance circuit, and the capacitance equivalent of the adjustable capacitance circuit connected to the circuit under the conduction angle alpha of the switching tube is as follows
Wherein C is a A fixed capacitance in the tunable capacitance circuit;
the system also comprises a frequency modulation tuning module, wherein the frequency modulation tuning module comprises a current detection circuit, an inversion conduction angle calculation unit and a driving circuit, the current detection circuit is used for collecting output current of the inverter, the inversion conduction angle calculation unit is used for calculating an inversion conduction angle theta 'according to the current collected by the current detection circuit, and the driving circuit drives the inverter by the inversion conduction angle theta'.
Preferably, the inversion conduction angle calculation unit comprises a quadrature signal generator, a Park conversion module, a PI control module and a frequency phase angle generator;
the quadrature signal generator is used for generating two corresponding voltage signals with equal amplitude and 90-degree phase difference according to the current acquired by the current detection circuit;
the Park conversion module is used for performing Park conversion on two orthogonal voltage signals generated by the orthogonal signal generator to obtain q-axis voltage and d-axis voltage;
the PI control module is used for performing PI processing according to the q-axis voltage obtained by the Park conversion module to obtain a frequency control quantity;
the frequency phase angle generator is used for calculating an inversion conduction angle theta 'according to the frequency control quantity and the current frequency omega of the inverter and outputting the inversion conduction angle theta' to the driving circuit.
Preferably, the adjustable capacitance circuit comprises a series resonance capacitor C connected in series with the primary side P With the transmitting coil L P A fixed capacitance C therebetween a Also comprises a fixed capacitor C connected in parallel with the capacitor a The switching circuit at two ends comprises a first MOS tube S 1 And a second MOS transistor S 2 The method comprises the steps of carrying out a first treatment on the surface of the The first MOS tube S 1 The S electrode of (C) is connected with the primary side series resonance capacitor C P With the transmitting coil L P Is the common end of the first MOS tube S 1 The D pole of (C) is connected with the second MOS tube S 2 D pole of the second MOS tube S 2 The S pole of (2) is connected with the fixed capacitor C a With the transmitting coil L P Is the common end of the first MOS tube S 1 G pole of (2) and the second MOS transistor S 2 The G pole of the capacitor is connected with the capacitor conduction angle calculation unit.
Preferably, the capacitance conduction angle calculating unit calculates the conduction angle alpha of the switching tube by adopting a disturbance observation method.
Preferably, the parameters of the system are determined by:
n1, determining the working frequency f of the system according to actual requirements 0 ；
N2, determining the transmitting coil L according to actual requirements P And the receiving coil L S The shape of the coil is a plane spiral coil, and the radius of the copper core of the winding is r respectively n1 And r n2 The radius of the winding is r respectively w1 And r w2 ；
N3, measuring the transmitting coil L P And the receiving coil L S The inductance and the internal resistance of the capacitor are determined according to the resonance relation to determine the primary side series resonance capacitor C P Secondary side series resonance capacitor C S Is a value of (2);
n4, determining the receiving coil L according to building requirements S Depth of embedding into concrete;
n5, calculating the concrete-air medium in the transmitting coil L P Parasitic capacitance C generated on PC And at the receiving coil L S Parasitic capacitance C generated on SC ；
N6, according to parasitic capacitance C PC And parasitic capacitance C SC Determining the fixed capacitance C a Is a value of (2).
Preferably, in the step N5, the parasitic capacitance C PC Calculated from the following formula:
ε a is the relative dielectric constant of air, epsilon rp For the transmitting coil L P Dielectric constant epsilon of the insulating layer of the conductor o Is vacuum dielectric constant, l P For the transmitting coil L P Length of the winding.
Preferably, in the step N5, the parasitic capacitance C SC Calculated from the following formula:
ε c is the relative dielectric constant epsilon of concrete rs For the receiving coil L S Relative dielectric constant of the insulating layer of the wire, l S For the receiving coil L S Length of the winding.
The invention also provides a control method of the concrete-air cross-medium wireless power transmission system, which is characterized by comprising the following steps:
at an operating frequency f 0 Initial switch conduction angle alpha 0 The system is operated, after the system is stabilized, the input voltage and current and the output voltage and current of the system are obtained, the efficiency of the system is calculated, and the conduction angle of a switching tube of the adjustable capacitance module is controlled in real time by adopting a disturbance observation method with the efficiency stabilized at a preset value as a target; and acquiring input current of a system, aiming at making the output voltage and the output current of the inverter be in phase, and controlling the conduction angle of the inverter by adopting PI control.
The concrete-air cross-medium wireless power transmission system and the control method thereof provided by the invention have the beneficial effects that: a concrete-air cross-medium wireless power transmission system is designed, and a receiving coil L thereof S The transmitting coil L is arranged in concrete P The adjustable capacitor module is arranged in the air, and a variable capacitor is added into a primary circuit to adjust the natural resonant frequency of the primary according to a disturbance observation method, so that the primary and the secondary work in a resonant state, and the system keeps higher transmission efficiency; the invention also designs the frequency modulation tuning module to control the phase of the output voltage of the inverter to be consistent with the phase of the primary side current, thereby leading the primary side circuit and the secondary side circuit of the WPT system to resonate and improving the output power and the efficiency of the WPT system. In the invention, the composite tuning control combining frequency modulation tuning and dynamic compensation tuning is adopted, so that higher output power and efficiency can be still kept when concrete medium changes (such as humidity changes and temperature changes), the application range is wide, the practicability is high, and the composite tuning control can be used for electric equipment in concreteStable, reliable and efficient charging.
Drawings
Fig. 1 is a schematic diagram of a concrete-air cross-medium wireless power transmission system according to an embodiment of the present invention;
FIG. 2 (a) is a schematic diagram of a magnetic field around a receiving coil in air according to an embodiment of the present invention;
fig. 2 (b) is a simulation diagram of a magnetic field around a receiving coil in concrete according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an equivalent circuit of a system for considering concrete effects according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a fm tuning control strategy according to an embodiment of the present invention;
fig. 5 is a flowchart of a fm tuning control strategy according to an embodiment of the present invention;
fig. 6 (a) is a topology diagram of a variable capacitance according to an embodiment of the present invention;
FIG. 6 (b) is a graph of the variation of the variable capacitance according to the embodiment of the present invention;
fig. 7 is a flow chart of a composite tuning control provided in an embodiment of the present invention;
fig. 8 (a) is a waveform diagram of output voltage and current of an inverter without using fm tuning control according to an embodiment of the present invention;
fig. 8 (b) is a waveform diagram of output voltage and current of the inverter after frequency modulation tuning control according to an embodiment of the present invention;
FIG. 9 (a) is a diagram showing primary and secondary current waveforms without dynamic compensation tuning control according to an embodiment of the present invention;
fig. 9 (b) is a waveform diagram of primary side current and secondary side current after dynamic compensation tuning control according to an embodiment of the present invention;
FIG. 10 (a) is a graph of efficiency before and after composite tuning provided by an embodiment of the present invention;
fig. 10 (b) is a graph of output power before and after composite tuning according to an embodiment of the present invention.
Detailed Description
The following examples are given for the purpose of illustration only and are not to be construed as limiting the invention, including the drawings for reference and description only, and are not to be construed as limiting the scope of the invention as many variations thereof are possible without departing from the spirit and scope of the invention.
In order to realize high-efficiency and high-output-power wireless power transmission in a concrete-air cross-medium scene, the embodiment of the invention firstly provides a concrete-air cross-medium wireless power transmission system, the circuit topology of which is shown in figure 1, and the system comprises a direct-current power supply U which is sequentially connected dc Inverter, primary side series resonance capacitor C P Transmitting coil L P And sequentially connected receiving coils L S Secondary side series resonance capacitor C S Equivalent load R L The key is that the system also comprises an adjustable capacitance module and a frequency modulation tuning module, which are used for realizing the composite tuning control of combining frequency modulation tuning and dynamic compensation tuning.
The adjustable capacitance module comprises an efficiency calculation unit, a capacitance conduction angle calculation unit and an adjustable capacitance circuit, wherein the adjustable capacitance circuit is connected in series with a primary side series resonance capacitor C P And a transmitting coil L P Between them; the efficiency calculation unit is used for calculating the input power and the output power of the system and calculating the efficiency of the system; the capacitance conduction angle calculation unit is used for calculating the conduction angle alpha of the switching tube to act on the adjustable capacitance circuit according to the system efficiency.
The frequency modulation tuning module comprises a current detection circuit, an inversion conduction angle calculation unit and a driving circuit, wherein the current detection circuit is used for collecting output current of the inverter, the inversion conduction angle calculation unit is used for calculating an inversion conduction angle theta 'according to the current collected by the current detection circuit, and the driving circuit drives the inverter by changing the inversion conduction angle theta'.
The transmitting coil L of this example P And a receiving coil L S The coil is formed by winding copper wires and is in a planar spiral structure, the radius of a wire of a winding coil is assumed to be 1mm, the radius of the winding coil is assumed to be 100mm, a transmitting coil is placed in air, a receiving coil is embedded in concrete, and at the moment, the inductance of the transmitting coil and the receiving coil is about L=23.6uh, and electricity is generatedThe resistance is r=600mΩ. The transmitting coil is placed in the air and the receiving coil is embedded in the concrete, the coil placed in the air is less influenced by the concrete, so that the inductance and the resistance hardly change, the inductance and the resistance of the coil embedded in the concrete change due to a large amount of concrete medium around the coil, at the moment, the working frequency is unchanged, the secondary circuit is not resonated, and the output power and the efficiency of the WPT system are greatly reduced.
To further illustrate the effect of the concrete medium on the WPT system, the magnetic field of the wireless power transfer system was simulated by simulation software. As can be seen by comparing fig. 2 (a) and fig. 2 (b), the maximum value of the ambient magnetic field strength of the receiving coil of the wireless power transmission system placed in the air is 50×10 -6 T, while the maximum value of the surrounding magnetic field strength of the receiving coil embedded in the concrete is reduced to 14×10 -6 T, the reason why the magnetic field strength around the receiving coil is reduced is that the concrete medium causes the wireless power transmission system to deviate from the resonance state, and simultaneously, eddy current loss is generated in the concrete because the concrete conductivity is greater than that of air.
Firstly, considering that compared with a WPT system in air, the concrete-air cross-medium WPT system is influenced by electromagnetic parameters of concrete so as to change various parameters of an original circuit, an equivalent circuit model of the concrete-air cross-medium WPT system is shown in figure 3, inductances of a transmitting coil and a receiving coil become equivalent series inductance Leff and equivalent series resistance ESR, and eddy current loss in the concrete is converted into eddy current loss resistance R in the circuit loss The relative permittivity of the concrete will create parasitic capacitances on the receiving coil and the transmitting coil, which have been converted into circuits in fig. 3 and are not shown separately. At the transmitting coil L P Parasitic capacitance C generated on PC Calculated by the following formula:
wherein ε a Is the relative dielectric constant of air, epsilon rp For transmitting coil L P Dielectric constant epsilon of the insulating layer of the conductor o Is vacuum dielectric constant, l P For transmitting coil L P Length of winding, r n1 For transmitting coil L P Radius of copper core of winding, r w1 For transmitting coil L P Radius of the winding.
At the receiving coil L S Parasitic capacitance C generated on SC Can be calculated by the following formula:
ε c is the relative dielectric constant epsilon of concrete rs For receiving coil L S Relative dielectric constant of the insulating layer of the wire, l S For receiving coil L S Length of winding, r n2 For receiving coil L S Radius of copper core of winding, r w2 For receiving coil L S Radius of the winding.
In order to overcome the problem of greatly reduced output power and efficiency of the WPT system caused by the concrete medium, the present embodiment adopts a composite tuning control of combining frequency modulation tuning and dynamic compensation tuning, and schematic diagrams and flowcharts of the frequency modulation tuning control are shown in fig. 4 and 5, respectively, and it can be seen that the inversion conduction angle calculation unit includes a quadrature signal generator, a Park conversion module, a PI control module and a frequency phase angle generator (FPG).
The quadrature signal generator is used for generating two corresponding voltage signals with equal amplitude and 90-degree phase difference according to the current collected by the current detection circuit. The Park conversion module is used for performing Park conversion on two orthogonal voltage signals generated by the orthogonal signal generator to obtain q-axis voltage and d-axis voltage. The PI control module is used for performing PI processing according to the q-axis voltage obtained by the Park conversion module to obtain a frequency control quantity. The frequency phase angle generator is used for calculating an inversion conduction angle theta 'according to the frequency control quantity and the frequency omega of the current inverter and outputting the inversion conduction angle theta' to the driving circuit.
The primary side current is collected and input into a quadrature signal generator, and the transfer function of the quadrature signal generator is as follows:
assume that the input signal is:
wherein U is n ，nω，φ n Is the amplitude, angular frequency and phase of the n-th harmonic of the input signal.
When the system is stable, it can be obtained that:
two voltage signals U with equal amplitude and 90-degree phase difference can be generated through the quadrature signal generator α(n) 、U β(n) Moreover, the above formula can find that the quadrature signal generator has good suppression effect on higher harmonics, and is little affected by distortion and interference of input signals.
The obtained quadrature signal is related to the phase of the input current, and the quadrature signal is obtained after park transformation:
from the above equation, the difference between the output phase and the input phase of the phase-locked loop can be represented by the value of the q-axis voltage, and when the value is 0, the synchronization of the input signal phase and the output signal phase of the system can be realized, thereby realizing the WPT system resonance.
The detuning of the receiving coil embedded in the concrete is more serious due to the concrete medium, so that a variable power supply is needed to be added in a primary circuitThe natural resonant frequency of the primary side is adjusted by the capacitor, and the natural resonant frequency of the primary side circuit is adjusted according to a disturbance observation method, so that both the primary side and the secondary side work in a resonant state. As shown in fig. 6 (a), the adjustable capacitance circuit adopts a PWM variable capacitance, which comprises a series resonant capacitor C connected in series with the primary side P And a transmitting coil L P A fixed capacitance C therebetween a Also comprises a fixed capacitor C connected in parallel a The switching circuits at two ends comprise a first MOS tube and a second MOS tube; the S electrode of the first MOS tube is connected with the primary side series resonance capacitor C P And a transmitting coil L P The D electrode of the first MOS tube is connected with the D electrode of the second MOS tube, and the S electrode of the second MOS tube is connected with the fixed capacitor C a And a transmitting coil L P The G pole of the first MOS tube and the G pole of the second MOS tube are connected with a capacitance conduction angle calculation unit.
The PWM variable capacitor has the advantages of continuously adjusting the size of the capacitor in a certain range and connecting the capacitor with the primary side series resonance capacitor C P The equivalent capacitance combined together is:
as an example, equivalent capacitance C eq The curve changing with the change of the conduction angle alpha of the switching tube is shown in fig. 6 (b), and it can be seen that the equivalent capacitance can be continuously adjusted within a certain range.
After determining the composition of the system, the parameters of the system may be determined by:
n1, determining the working frequency f of the system according to actual requirements 0 ；
N2, determining the transmitting coil L according to actual requirements P And a receiving coil L S The shape of the coil is a plane spiral coil, and the radius of the copper core of the winding is r respectively n1 And r n2 The radius of the winding is r respectively w1 And r w2 ；
N3, measuring transmitting coil L P And a receiving coil L S The inductance and the internal resistance of the capacitor are determined according to the resonance relation to determine the primary side series resonance capacitor C P Auxiliary pairSide series resonance capacitor C S Is a value of (2);
n4, determining the receiving coil L according to the building requirement S Depth of embedding into concrete;
n5, calculating the concrete-air medium in the transmitting coil L P Parasitic capacitance C generated on PC And at the receiving coil L S Parasitic capacitance C generated on SC ；
N6, according to parasitic capacitance C PC And parasitic capacitance C SC Determining a fixed capacitance C a Is a value of (2).
The step N6 specifically includes the steps of:
n61 according to parasitic capacitance C PC The change range of the primary inductance is determined according to the size of the parasitic capacitance C SC Determining the secondary side inductance variation range;
n62, calculating and determining the required variable capacitance C according to the primary and secondary side inductance change range kb Is a range of variation of (2);
n63 according to variable capacitance C kb The fixed capacitance C is calculated from the variation range of the (C) and the range of the conduction angle alpha of the switching tube a A variation range of (2), the maximum value of which is C a_max ；
N64, at [1.2C a_max ,2C a_max ]A value is selected as the fixed capacitor C a Is used for the parameter values of (a).
The capacitor C is fixed through the design of the steps N61 to N64 a Can avoid the fixed capacitance C a Too small a value does not meet the adjustment requirement, or too large a value makes the adjustment less sensitive.
After the system parameters are determined, the system parameters need to be controlled in the working process of the system, specifically: at an operating frequency f 0 Initial switch conduction angle alpha 0 The system is operated, after the system is stabilized, the input voltage and current and the output voltage and current of the system are obtained, the efficiency of the system is calculated, and the conduction angle of a switching tube of the adjustable capacitance module is controlled in real time by adopting a disturbance observation method with the efficiency stabilized at a preset value as a target; and obtaining the input current of the system, aiming at making the output voltage and the output current of the inverter be in phaseAnd controlling the conduction angle of the inverter by adopting PI control. In the control of the system, the composite tuning control is mainly performed, fig. 7 is a flow chart of the composite tuning control, the direct current power supply converts direct current into high-frequency alternating current through the inverter, and the electric energy is coupled to the receiving coil through the transmitting coil in the form of an electromagnetic field and finally consumed by the load. Through the combined action of frequency modulation tuning and variable capacitance tuning, the concrete medium can influence the WPT system, and the system can be ensured to work in an optimal state.
In order to further explain the effect of the composite tuning control, the concrete-air cross-medium wireless power transmission system is simulated by adopting the Simulink, in the simulation process, the detuning phenomenon caused by the concrete medium in the actual situation is simulated by changing the value of the secondary side inductance, the secondary side inductance takes the value of 21.3 uH-25.3 uH, the inverter output voltage current waveform which does not adopt the frequency modulation tuning control is shown in fig. 8 (a), the inverter output current phase lags behind the voltage phase, and the current phase lag is shown in the figure, so that the WPT system is inductive as a whole at the moment, and the amplitude of the inverter output current is reduced. After frequency modulation tuning, the waveform of the output voltage and current of the inverter is improved, and as shown in fig. 8 (b), the phase difference between the output voltage and the output current of the inverter is 0, and the amplitude of the output current of the inverter is increased. To determine whether the secondary circuit is in a resonant state, the phase difference of the primary current and the secondary current may be compared, and when the WPT system resonates, the primary current and the secondary current are 90 ° out of phase. Fig. 9 (a) is a waveform diagram of a primary side current and a secondary side current which do not adopt dynamic compensation tuning, and it can be seen from the diagram that the phase difference between the primary side current and the secondary side current exceeds 90 degrees, which indicates that the secondary side circuit is not in a resonance state at this time, and the input impedance phase of the inverter is 0 at this time, but the overall efficiency of the WPT system is not improved, after adopting dynamic compensation tuning, the primary side current and the secondary side current of the WPT system can be ensured to be in the resonance state, and the waveform diagram of the primary side current and the secondary side current is shown in fig. 9 (b).
Fig. 10 (a) and fig. 10 (b) are graphs of WPT system efficiency and output power before and after tuning, and it can be seen that WPT is highest only at the resonant frequency before tuning, but efficiency is continuously reduced after WPT is detuned, and efficiency of the WPT system can be stabilized at a higher level after tuning. Meanwhile, after the composite tuning is adopted, the output power of the WPT system is also improved.
In summary, the embodiment of the invention provides a concrete-air cross-medium wireless power transmission system and a control method thereof, and designs the concrete-air cross-medium wireless power transmission system, which receives a coil L S The transmitting coil L is arranged in concrete P The adjustable capacitor module is arranged in the air, and a variable capacitor is added into a primary circuit to adjust the natural resonant frequency of the primary according to a disturbance observation method, so that the primary and the secondary work in a resonant state, and the system keeps higher transmission efficiency; the invention also designs the frequency modulation tuning module to control the phase of the output voltage of the inverter to be consistent with the phase of the primary side current, thereby leading the primary side circuit and the secondary side circuit of the WPT system to resonate and improving the output power and the efficiency of the WPT system. In the invention, the composite tuning control combining frequency modulation tuning and dynamic compensation tuning is adopted, so that higher output power and efficiency can be still maintained when a concrete medium changes (such as humidity changes and temperature changes), the application range is wide, the practicability is high, and the electric equipment in the concrete can be charged stably, reliably and efficiently.
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (9)
1. A concrete-air cross-medium wireless power transmission system comprises a DC power supply, an inverter and a primary side series resonance capacitor C which are sequentially connected P Transmitting coil L P And sequentially connected receiving coils L S Secondary side series resonance capacitor C S Equivalent load R L The method is characterized in that:
the receiving coil L S Is installed in concrete, and the transmitting coil L P Installed in the airIn (a) and (b);
the system also comprises an adjustable capacitance module, wherein the adjustable capacitance module comprises an efficiency calculation unit, a capacitance conduction angle calculation unit and an adjustable capacitance circuit, and the adjustable capacitance circuit is connected in series with the primary side series resonance capacitor C P With the transmitting coil L P Between them; the efficiency calculation unit is used for calculating the input power and the output power of the system and calculating the efficiency of the system; the capacitance conduction angle calculation unit is used for calculating the conduction angle alpha of the switching tube according to the system efficiency and acting on the adjustable capacitance circuit, and the capacitance equivalent of the adjustable capacitance circuit connected to the circuit under the conduction angle alpha of the switching tube is as follows
Wherein C is a A fixed capacitance in the tunable capacitance circuit;
the system also comprises a frequency modulation tuning module, wherein the frequency modulation tuning module comprises a current detection circuit, an inversion conduction angle calculation unit and a driving circuit, the current detection circuit is used for collecting output current of the inverter, the inversion conduction angle calculation unit is used for calculating an inversion conduction angle theta 'according to the current collected by the current detection circuit, and the driving circuit drives the inverter by the inversion conduction angle theta'.
2. A concrete-air cross-media wireless power transfer system as claimed in claim 1, wherein: the inversion conduction angle calculation unit comprises a quadrature signal generator, a Park conversion module, a PI control module and a frequency phase angle generator;
the quadrature signal generator is used for generating two corresponding voltage signals with equal amplitude and 90-degree phase difference according to the current acquired by the current detection circuit;
the Park conversion module is used for performing Park conversion on two orthogonal voltage signals generated by the orthogonal signal generator to obtain q-axis voltage and d-axis voltage;
the PI control module is used for performing PI processing according to the q-axis voltage obtained by the Park conversion module to obtain a frequency control quantity;
the frequency phase angle generator is used for calculating an inversion conduction angle theta 'according to the frequency control quantity and the current frequency omega of the inverter and outputting the inversion conduction angle theta' to the driving circuit.
3. A concrete-air cross-media wireless power transfer system as claimed in claim 1, wherein: the adjustable capacitance circuit comprises a series resonance capacitor C connected in series with the primary side P With the transmitting coil L P A fixed capacitance C therebetween a Also comprises a fixed capacitor C connected in parallel with the capacitor a The switching circuit at two ends comprises a first MOS tube S 1 And a second MOS transistor S 2 The method comprises the steps of carrying out a first treatment on the surface of the The first MOS tube S 1 The S electrode of (C) is connected with the primary side series resonance capacitor C P With the transmitting coil L P Is the common end of the first MOS tube S 1 The D pole of (C) is connected with the second MOS tube S 2 D pole of the second MOS tube S 2 The S pole of (2) is connected with the fixed capacitor C a With the transmitting coil L P Is the common end of the first MOS tube S 1 G pole of (2) and the second MOS transistor S 2 The G pole of the capacitor is connected with the capacitor conduction angle calculation unit.
4. A concrete-air cross-media wireless power transfer system as claimed in claim 3, wherein: the capacitance conduction angle calculation unit calculates the conduction angle alpha of the switching tube by adopting a disturbance observation method.
5. A concrete-air trans-media wireless power transfer system according to claim 1, wherein parameters of the system are determined by:
n1, determining the working frequency f of the system according to actual requirements 0 ；
N2, determining the transmitting coil L according to actual requirements P And the receiving coil L S The shape of the coil is a plane spiral coil, and the radius of the copper core of the winding is r respectively n1 And r n2 The radius of the winding is r respectively w1 And r w2 ；
N3, measuring the transmitting coil L P And the receiving coil L S The inductance and the internal resistance of the capacitor are determined according to the resonance relation to determine the primary side series resonance capacitor C P Secondary side series resonance capacitor C S Is a value of (2);
n4, determining the receiving coil L according to building requirements S Depth of embedding into concrete;
n5, calculating the concrete-air medium in the transmitting coil L P Parasitic capacitance C generated on PC And at the receiving coil L S Parasitic capacitance C generated on SC ；
N6, according to parasitic capacitance C PC And parasitic capacitance C SC Determining the fixed capacitance C a Is a value of (2).
6. A concrete-air trans-medium wireless power transfer system according to claim 5, characterized in that in said step N5, parasitic capacitance C PC Calculated from the following formula:
ε a is the relative dielectric constant of air, epsilon rp For the transmitting coil L P Dielectric constant epsilon of the insulating layer of the conductor o Is vacuum dielectric constant, l P For the transmitting coil L P Length of the winding.
7. A concrete-air trans-medium wireless power transfer system according to claim 6, characterized in that in said step N5, parasitic capacitance C SC Calculated from the following formula:
ε c is the relative dielectric constant epsilon of concrete rs For the receiving coil L S Relative dielectric constant of the insulating layer of the wire, l S For the receiving coil L S Length of the winding.
8. The concrete-air cross-medium wireless power transmission system according to claim 5, wherein said step N6 specifically comprises the steps of:
n61 according to parasitic capacitance C PC The change range of the primary inductance is determined according to the size of the parasitic capacitance C SC Determining the secondary side inductance variation range;
n62, calculating and determining the required variable capacitance C according to the primary and secondary side inductance change range kb Is a range of variation of (2);
n63 according to variable capacitance C kb The fixed capacitance C is calculated from the variation range of the (C) and the range of the conduction angle alpha of the switching tube a A variation range of (2), the maximum value of which is C a_max ；
N64, at [1.2C a_max ,2C a_max ]A value is selected as the fixed capacitor C a Is used for the parameter values of (a).
9. A control method of a concrete-air cross-medium wireless power transmission system according to any one of claims 1 to 8, comprising:
at an operating frequency f 0 Initial switch conduction angle alpha 0 The system is operated, after the system is stabilized, the input voltage and current and the output voltage and current of the system are obtained, the efficiency of the system is calculated, and the conduction angle of a switching tube of the adjustable capacitance module is controlled in real time by adopting a disturbance observation method with the efficiency stabilized at a preset value as a target; and acquiring input current of a system, aiming at making the output voltage and the output current of the inverter be in phase, and controlling the conduction angle of the inverter by adopting PI control.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310196561.2A CN116247831B (en) | 2023-03-03 | 2023-03-03 | Concrete-air cross-medium wireless power transmission system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310196561.2A CN116247831B (en) | 2023-03-03 | 2023-03-03 | Concrete-air cross-medium wireless power transmission system and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116247831A true CN116247831A (en) | 2023-06-09 |
| CN116247831B CN116247831B (en) | 2024-07-23 |
Family
ID=86632859
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310196561.2A Active CN116247831B (en) | 2023-03-03 | 2023-03-03 | Concrete-air cross-medium wireless power transmission system and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116247831B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103199634A (en) * | 2013-03-01 | 2013-07-10 | 西安理工大学 | Magnetic coupling resonant type wireless power transmission phase control capacitance tuning device |
| CN104993617A (en) * | 2015-07-07 | 2015-10-21 | 中国矿业大学(北京) | Magnetic-resonance wireless power transmission system and impedance matching method thereof |
| CN109302070A (en) * | 2018-10-09 | 2019-02-01 | 李建科 | Power converter circuit topological structure and its control method |
| US20210184499A1 (en) * | 2019-12-12 | 2021-06-17 | University Of Macau | Wireless charging circuit and system |
| CN114243945A (en) * | 2021-11-12 | 2022-03-25 | 深圳供电局有限公司 | Wireless charging system and resonant network matching method thereof |
| CN115693978A (en) * | 2022-11-14 | 2023-02-03 | 哈尔滨工业大学（深圳） | Multi-load wireless charging system based on dynamic compensation of switched capacitor |
-
2023
- 2023-03-03 CN CN202310196561.2A patent/CN116247831B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103199634A (en) * | 2013-03-01 | 2013-07-10 | 西安理工大学 | Magnetic coupling resonant type wireless power transmission phase control capacitance tuning device |
| CN104993617A (en) * | 2015-07-07 | 2015-10-21 | 中国矿业大学(北京) | Magnetic-resonance wireless power transmission system and impedance matching method thereof |
| CN109302070A (en) * | 2018-10-09 | 2019-02-01 | 李建科 | Power converter circuit topological structure and its control method |
| US20210184499A1 (en) * | 2019-12-12 | 2021-06-17 | University Of Macau | Wireless charging circuit and system |
| CN114243945A (en) * | 2021-11-12 | 2022-03-25 | 深圳供电局有限公司 | Wireless charging system and resonant network matching method thereof |
| CN115693978A (en) * | 2022-11-14 | 2023-02-03 | 哈尔滨工业大学（深圳） | Multi-load wireless charging system based on dynamic compensation of switched capacitor |
Non-Patent Citations (1)
| Title |
|---|
| 廖师师: ""谐振式无线电能传输系统恒功率输出控制及频率跟踪控制的研究"", 《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》, no. 3, 15 February 2023 (2023-02-15), pages 8 - 41 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116247831B (en) | 2024-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Qu et al. | Wireless power transfer using domino-resonator for 110-kV power grid online monitoring equipment | |
| Yan et al. | A monitoring equipment charging system for HVTL based on domino-resonator WPT with constant current or constant voltage output | |
| CN106740238B (en) | Wireless charging circuit of electric automobile and control method thereof | |
| CN103560593B (en) | A kind of control method of field coupled type radio energy transmission system | |
| US11770025B2 (en) | Wireless power transmission appratus and control method thereof | |
| CN110429718B (en) | Constant-current/constant-voltage control method of wireless power transmission system based on primary side parameter identification | |
| CN103607056B (en) | Compensation arrangement in magnetic inductive wireless power transmission equipment and compensation method thereof | |
| Lin et al. | Accurate maximum power tracking of wireless power transfer system based on simulated annealing algorithm | |
| Jiang et al. | A fractional-order wireless power transfer system insensitive to resonant frequency | |
| CN110098663B (en) | Wireless power transmission system and configuration method of high-voltage online monitoring equipment | |
| CN103280900A (en) | High-voltage power-taking and power-supply system based on wireless electricity transmission technology | |
| Li et al. | Study on efficiency maximization design principles for wireless power transfer system using magnetic resonant coupling | |
| CN111532151A (en) | System and method for wireless charging of electric automobile | |
| CN103607124A (en) | Power taking device based on non-closed current transformer and control method thereof | |
| Qu et al. | Dynamic modeling for the wireless power transfer system in domino structure | |
| CN109067005B (en) | Contactless power supply device for rotating electromechanical apparatus | |
| CN116247831B (en) | Concrete-air cross-medium wireless power transmission system and control method thereof | |
| CN203607929U (en) | Compensation device in magnetic induction type wireless electric energy transmission equipment | |
| CN117674445A (en) | Underwater WPT system output power sweep frequency optimizing method considering eddy current loss | |
| CN103944280A (en) | Device and method for dynamic tuning of sending end of wireless power transmission device | |
| CN103944279B (en) | A kind of wireless power transmission equipment receiving terminal dynamic tuning device and tuning methods thereof | |
| CN206561781U (en) | A kind of electric automobile wireless charging circuit | |
| CN115173579A (en) | Automatic tuning method based on transmitting end current voltage detection | |
| CN210806860U (en) | Wireless power transmission system with constant voltage output characteristic | |
| Hou et al. | Wireless power transfer system of on-line monitoring equipment for high voltage transmission line based on double-sided LCC resonant network |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |