CN110971009B - Control method of wireless power transmission system - Google Patents
Control method of wireless power transmission system Download PDFInfo
- Publication number
- CN110971009B CN110971009B CN201910987980.1A CN201910987980A CN110971009B CN 110971009 B CN110971009 B CN 110971009B CN 201910987980 A CN201910987980 A CN 201910987980A CN 110971009 B CN110971009 B CN 110971009B
- Authority
- CN
- China
- Prior art keywords
- output power
- duty ratio
- relation
- mutual inductance
- transmission system
- 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.)
- Active
Links
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
-
- 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
-
- 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)
- Computer Networks & Wireless Communication (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a control method of a wireless power transmission system, which comprises the steps of establishing a mathematical model of the wireless power transmission system; according to the system mathematical model, the optimal duty ratio and the optimal working frequency are obtained through analysis and calculation, the output power of the system is predicted, and the mathematical model is established by the following steps: respectively calculating and obtaining the input power, the output power and the system working frequency of the wireless power transmission system; according to the equivalent impedance Z r Changing the angular frequency to obtain Z r After the conversion formula of (a), the load resistance R is respectively obtained L And a coil mutual inductance M; obtaining the load resistance R according to the time sequence diagram L The relation between the coil mutual inductance coefficient M and the angle; and a new algorithm model is utilized to predict and control a mathematical expression of a cost function, an optimal duty ratio of ideal output power is obtained through minimization of an objective function, gain adjustment and measurement are not needed, the cost and complexity of the WPT system are greatly reduced, and the transmission efficiency of the system is remarkably improved.
Description
Technical Field
The invention relates to the technical field of wireless power transmission, in particular to a control method of a wireless power transmission system.
Background
Wireless Power Transmission (WPT) is a novel power transmission mode, gets rid of the constraint of the traditional wired mode, greatly increases the flexibility, the aesthetic property and the safety of electric equipment, reduces the occurrence of faults such as circuit leakage and the like, and increases the personal safety and the economic guarantee. WPT systems present a number of technical difficulties in succession, misalignment between the coupled coils being unavoidable, this feature leading to a change in mutual inductance and hence in output power, and hence control of the output power is essential. To reduce the cost, size and complexity of WPT systems, the controller should be implemented on the master side without any measurement and communication equipment on the secondary side. Primary side control may enable regulation of the inverter output voltage by inverter voltage control, phase shift control being a technique commonly used in WPT systems because the output voltage does not contain a dc component. The harmonic content is lower than that of the Asymmetrical Duty Cycle (ADC) control and Asymmetrical Clamping Mode (ACM) control technologies.
In the prior art, however, in order to regulate the output power according to the primary-side control method, the load resistance and the inductance must be identified throughout the operation. By switching an additional compensation capacitance to the main circuit, the system will operate in two different modes in which the identification formulas for load impedance and mutual inductance can be derived. But the need for an additional capacitor switch and control increases the number of components, cost and complexity of the WPT system. The on-line estimation method based on the Goertzel algorithm needs to estimate the mean square error corresponding to all the mutual inductance values, and is large in calculation amount, difficult to realize and time-consuming. Although the resistance and mutual inductance can be estimated simultaneously by measuring the input voltage and current, it is a mathematical problem based on the resonance frequency, which has a great challenge.
Disclosure of Invention
In order to find a more effective implementation scheme, the invention provides a control method of a wireless power transmission system, and the optimal duty ratio of ideal output power is obtained through minimizing an objective function, so that gain adjustment and measurement are not needed, the cost and complexity of the WPT system are greatly reduced, and the transmission efficiency of the system is remarkably improved.
In order to achieve the above object, the present invention discloses a control method of a wireless power transmission system, comprising:
establishing a mathematical model of a wireless power transmission system;
and analyzing and calculating according to the mathematical model of the system to obtain the optimal duty ratio and the optimal working frequency, and predicting the output power of the system.
Preferably, the establishing a mathematical model of the wireless power transfer system includes:
respectively calculating and obtaining the input power, the output power and the system working frequency of the wireless power transmission system;
according to the equivalent impedance Z r Changing the angular frequency to obtain Z r After the conversion formula of (a), the load resistance R is respectively obtained L And a coil mutual inductance M;
obtaining the load resistance R according to the time sequence diagram L The relation between the coil mutual inductance coefficient M and the angle;
and establishing a mathematical expression of the cost function by using the new algorithm model predictive control.
Preferably, the input power and the output power are respectively obtained through an equivalent circuit, and the working frequency of the system is obtained according to the input power and the output power, wherein the input power isThe output power is
Preferably, the equivalent impedance Z r ＝R r +jX r Wherein R is r X is the equivalent resistance component r Is equivalent reactance component and converts angular frequency omega into angular frequency omega of system working at zero phase 02 Obtaining R of system frequency at zero phase r And X cr And get a new Z r Mathematical expression, sequentially obtaining the load resistance R according to the transformation formula L And a coil mutual inductance M.
Preferably, the load resistor R L The method comprises the following steps:
the coil mutual inductance coefficient M is as follows:
preferably, the equivalent impedance R is obtained according to the relation between the voltages at the two sides of the inverter obtained by conducting the MOSFET tubes of the upper bridge arm and the lower bridge arm L The relation between the coil mutual inductance M and the angle,
preferably, the specific process of establishing the mathematical expression of the cost function by using the new algorithm model predictive control is as follows:
determining the relation between the output power and the duty ratio at any moment, and respectively deducing the relation between the output power and the input direct current bus voltage, the load equivalent resistance, the mutual inductance coefficient and the duty ratio D;
determining a relation between the output power and the duty ratio D at the next moment of any moment;
establishing a cost function according to the relation between the output power at any moment and the next moment and the duty ratio D
Preferably, the relation between the output power and the duty ratio D at any time is:
the relation between the output power and the duty ratio D at the next time of any time is as follows:
preferably, the specific process of predicting the output power of the system includes:
determining the optimal solution of the cost function J, namely the minimum value of the cost function J according to the expression of the cost function, and calculating the obtained load equivalent resistance R according to the known input voltage L And the coil mutual inductance coefficient M to obtain the optimal duty ratio D (K).
Preferably, the on and off of the MOSFET is controlled according to the obtained optimal duty ratio D (K), and the inversion frequency of the system is determined.
Compared with the prior art, the control method of the wireless power transmission system has the following beneficial effects:
the technical scheme is that a new control algorithm is utilized to predict a control model MPC, a circuit equivalent diagram of a WPT system is obtained, a mathematical expression of a mutual inductance coefficient of a load resistor and a coil is established, a mathematical expression of output power and a duty ratio D is obtained, and an optimal function expression J is established through an MPC algorithm, so that an optimal duty ratio D can be obtained. Compared with the traditional method PWM carrier wave method and PI control method, the controller has faster response speed than the traditional PI controller. The optimal duty ratio is obtained in real time according to the load resistance change, the system efficiency is higher, the gain is not required to be adjusted, the measurement is not required, and the cost, the size and the complexity of the WPT system are greatly reduced.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
figure 1 is an equivalent circuit diagram a of a WPT system;
figure 2 is an equivalent circuit diagram b of the WPT system;
FIG. 3 is a simplified circuit diagram c of FIG. 1 after equivalent conversion of circuit impedance to the primary side;
fig. 4 is an overall equivalent diagram of a wireless power transfer system of the present invention;
fig. 5 is a schematic diagram of phase shift control of a full-bridge inverter with corresponding waveforms and gating signals according to the present invention.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
Referring to fig. 1 to 5, the present invention discloses a control method of a wireless power transmission system, which includes:
establishing a mathematical model of a wireless power transmission system;
the establishing the mathematical model of the wireless power transmission system comprises the following steps:
respectively calculating and obtaining the input power, the output power and the system working frequency of the wireless power transmission system;
wherein the input power and the output power are respectively obtained through the basic formulas of the circuits of the equivalent circuit diagrams b and c, and the working frequency of the system is obtained according to the input power and the output power, and the input power is thatThe output power is +.>The output power and the input power are obtained by equivalent circuits shown in fig. 2 and 3 according to basic formulas of the circuits, wherein R1, L1, R2, L2, C2 and M (design values) are known.
At the same time, the C1 value can be obtained by working at zero phase angle frequency according to the frequency, namely The primary zero phase angle frequency is designed as the secondary resonant frequency.
According to the equivalent impedance Z r Changing the angular frequency to obtain Z r After the conversion formula of (a), the load resistance R is respectively obtained L And a coil mutual inductance M;
the equivalent impedance Z r ＝R r +jX r Wherein R is r X is the equivalent resistance component r For equivalent reactance components, transforming angular frequency ω to angular frequency ω at which the system operates at zero phase 02 Obtaining R of system frequency at zero phase r And X cr And get a new Z r Mathematical expression, in turn according to transformation formulaObtaining the load resistance R L And a coil mutual inductance M.
Obtaining R r And X cr After which a new Z is obtained r The mathematical expression is used to determine the degree of freedom,
wherein, the liquid crystal display device comprises a liquid crystal display device,
and sequentially obtaining the load resistance R according to a conversion formula L And a coil mutual inductance M.
The load resistor R L The method comprises the following steps:the coil mutual inductance coefficient M is as follows:
obtaining the load resistance R according to the time sequence diagram L The relation between the coil mutual inductance coefficient M and the angle;
according to the relation of the voltages at two sides of the inverter obtained by conducting the MOSFET tubes of the upper bridge arm and the lower bridge arm, the equivalent impedance R is obtained respectively L The relation between the coil mutual inductance M and the angle,
and establishing a mathematical expression of the cost function by using the new algorithm model predictive control.
The specific process of establishing the mathematical expression of the cost function by utilizing the new algorithm model predictive control is as follows:
determining the relation between the output power and the duty ratio at any moment, and respectively deducing the relation between the output power and the input direct current bus voltage, the load equivalent resistance, the mutual inductance coefficient and the duty ratio D;
determining a relation between the output power and the duty ratio D at the next moment of any moment;
according to any time and the next timeEstablishing a cost function according to the relation between the carved output power and the duty ratio D
And analyzing and calculating according to the mathematical model of the system to obtain the optimal duty ratio and the optimal working frequency, and predicting the output power of the system.
The relation between the output power and the duty ratio D at any moment is as follows:
the relation between the output power and the duty ratio D at the next time of any time is as follows:
in this scheme, fig. 1 is an equivalent circuit diagram of the WPT system, the simplified circuit diagram of the diagram c can be obtained by equivalent conversion of circuit impedance to the primary side, the vector Zin is the equivalent impedance of the whole circuit seen from the power supply end,where zr=rr+ jXr (equivalent impedance to the secondary side of the coil in abc),
the optimal duty ratio and the optimal working frequency are obtained by analysis and calculation according to the mathematical model of the system, and the specific process of predicting the output power of the system is as follows:
determining an optimum of the cost function J from the expression of the cost functionSolution, i.e. minimum of cost function J, and based on known input voltage, calculated load equivalent resistance R L And the coil mutual inductance coefficient M to obtain the optimal duty ratio D (K).
And according to the obtained optimal duty ratio D (K), controlling the on and off of the MOSFET, determining the inversion frequency of the system, wherein compared with a traditional PWM carrier method and a PI control method, the controller has a faster response speed than a traditional PI controller. And the optimal duty ratio is obtained in real time according to the load resistance change, so that the system efficiency is higher.
According to the technical scheme, the optimal duty ratio of ideal output power is obtained through minimization of the objective function, the method is simple and feasible, the gain is not required to be adjusted, measurement is not required, the cost, the size and the complexity of the WPT system are greatly reduced, the controller is simple in structure and low in cost, the efficiency of the system is improved, the theme of pursuing high efficiency and saving resources in the current market is met, and the method has significance for practical application value.
The foregoing is only a partial embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.
Claims (7)
1. A control method of a wireless power transmission system, comprising:
establishing a mathematical model of a wireless power transfer system, comprising:
respectively calculating and obtaining the input power, the output power and the system working frequency of the wireless power transmission system;
according to the equivalent impedance Z r Changing the angular frequency to obtain Z r After the conversion formula of (a), the load resistance R is respectively obtained L And a coil mutual inductance M;
obtaining the load resistance R according to the time sequence diagram L The relation between the coil mutual inductance coefficient M and the angle;
the mathematical expression of the cost function is established by utilizing the new algorithm model predictive control, and the specific process is as follows:
determining the relation between the output power and the duty ratio at any moment, and respectively deducing the relation between the output power and the input direct current bus voltage, the load equivalent resistance, the mutual inductance coefficient and the duty ratio D;
determining a relation between the output power and the duty ratio D at the next moment of any moment;
the relation between the output power and the duty ratio D at any moment is as follows:
the relation between the output power and the duty ratio D at the next time of any time is as follows:
establishing a cost function according to the relation between the output power at any moment and the next moment and the duty ratio D
And analyzing and calculating according to the mathematical model of the system to obtain the optimal duty ratio and the optimal working frequency, and predicting the output power of the system.
2. The method of claim 1, wherein the input power and the output power are obtained by an equivalent circuit, and the operating frequency of the system is obtained based on the input power and the output power, the input power beingThe output power is +.>
3. A control method of a radio energy transmission system according to claim 1, characterized in that the equivalent impedance Z r ＝R r +jX r Wherein R is r X is the equivalent resistance component r Is equivalent reactance component and converts angular frequency omega into angular frequency omega of system working at zero phase 02 Obtaining R of system frequency at zero phase r And X cr And get a new Z r Mathematical expression, sequentially obtaining the load resistance R according to the transformation formula L And a coil mutual inductance M.
4. A control method of a radio energy transmission system according to claim 3, characterized in that the load resistor R L The method comprises the following steps:
the coil mutual inductance coefficient M is as follows:
5. the control method of a wireless power transmission system according to claim 4, wherein the voltage relations between both sides of the inverter are obtained according to the conduction of the MOSFET tubes of the upper and lower bridge arms, and the equivalent impedance R is obtained respectively L The relation between the coil mutual inductance M and the angle,
6. the method for controlling a wireless power transmission system according to claim 1, wherein the optimal duty ratio and the optimal operating frequency are obtained by analysis and calculation according to the mathematical model of the system, and the specific process of predicting the output power of the system is as follows:
determining the optimal solution of the cost function J, namely the minimum value of the cost function J according to the expression of the cost function, and calculating the obtained load equivalent resistance R according to the known input voltage L And the coil mutual inductance coefficient M to obtain the optimal duty ratio D (K).
7. The control method of a wireless power transmission system according to claim 6, wherein the inversion frequency of the system is determined by controlling the on and off of the MOSFETs according to the obtained optimal duty ratio D (K).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910987980.1A CN110971009B (en) | 2019-10-17 | 2019-10-17 | Control method of wireless power transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910987980.1A CN110971009B (en) | 2019-10-17 | 2019-10-17 | Control method of wireless power transmission system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110971009A CN110971009A (en) | 2020-04-07 |
| CN110971009B true CN110971009B (en) | 2023-08-11 |
Family
ID=70029723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910987980.1A Active CN110971009B (en) | 2019-10-17 | 2019-10-17 | Control method of wireless power transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110971009B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112765763B (en) * | 2020-12-02 | 2022-10-28 | 重庆大学 | Secondary characteristic value-based multi-relay MC-WPT system analysis method |
| CN112968535B (en) * | 2021-03-30 | 2023-05-16 | 西安理工大学 | Load coil position detection method for omnidirectional wireless power transmission system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109391044A (en) * | 2018-11-14 | 2019-02-26 | 中国矿业大学 | A kind of efficient pressure stabilizing complex control system of inductive electric energy transmission system and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105659470B (en) * | 2013-08-06 | 2019-04-30 | 香港大学 | Method for parameter identification, load monitoring and output power in wireless power transfer system |
| US10186894B2 (en) * | 2015-04-30 | 2019-01-22 | Aptiv Technologies Limited | Wireless battery charger with wireless control system |
-
2019
- 2019-10-17 CN CN201910987980.1A patent/CN110971009B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109391044A (en) * | 2018-11-14 | 2019-02-26 | 中国矿业大学 | A kind of efficient pressure stabilizing complex control system of inductive electric energy transmission system and method |
Non-Patent Citations (1)
| Title |
|---|
| Jeff Po-Wa Chow 等.Use of Transmitter-Side Electrical Information to Estimate Mutual Inductance and Regulate Receiver-Side Power in Wireless Inductive Link.IEEE TRANSACTIONS ON POWER ELECTRONICS.2019,31(09),第6079-6091页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110971009A (en) | 2020-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109391044B (en) | Voltage stabilization comprehensive control system and method for inductive power transmission system | |
| CN109245536A (en) | A kind of circuit topological structure suitable for the transmission of two-way near field electric energy | |
| CN109196769A (en) | For driving the driving circuit based on buck converter of the motor of compressor and condenser fan | |
| CN109130903B (en) | Low-voltage high-power wireless charging system with bilateral LCCL-T topology | |
| CN108656994B (en) | Electric automobile IPT system of variable capacitance | |
| CN109245542A (en) | A kind of symmetrical power converter circuit topological structure and its control method | |
| WO2012125590A9 (en) | Method and apparatus for controlling lcl converters using asymmetric voltage cancellation techniques | |
| CN208955902U (en) | A kind of circuit topological structure suitable for the transmission of two-way near field electric energy | |
| CN108736757B (en) | Current source type electrolytic capacitor-free high-frequency chain converter system | |
| CN112366677B (en) | Multi-phase-shift model prediction control method for three-port power electronic transformer | |
| CN111478572B (en) | Single-pole AC-DC converter modal smooth switching and power factor correction control method | |
| CN110971009B (en) | Control method of wireless power transmission system | |
| CN109039121A (en) | A kind of high-frequency isolation type ac-dc conversion circuit and its control method | |
| US20230198374A1 (en) | Wireless Power Transfer (WPT) System Regulation Method and System for Implementing ZVS in Wide Power Range | |
| WO2023193650A1 (en) | Method for identifying both loads and mutual inductance of multi-load wireless power transfer system | |
| CN111082540B (en) | Multi-tap wireless power transmission system and efficiency optimization method thereof | |
| CN116780788A (en) | Wireless charging system based on LCC-S compensation topological junction and control method thereof | |
| CN111181420A (en) | Single-phase Vienna rectifier and control method thereof | |
| CN113595256B (en) | Method for improving light load efficiency of SS structure WPT system based on hybrid modulation technology | |
| CN107579659B (en) | Constant-current resonant DC conversion circuit and method adapting to high parasitic parameters of transformer | |
| Mandal et al. | Optimizing Transformer RMS Current Using Single Phase Shift Variable Frequency Modulation for Dual Active Bridge DC-DC Converter | |
| Liu et al. | Asymmetric modulation of bridgeless single‐stage full‐bridge AC–DC converter for active power factor correction and zero voltage switching | |
| CN114598045B (en) | Wide-load-range high-efficiency WPT system based on improved bilateral switch key position modulation | |
| CN116780910B (en) | Test power supply circuit and control method | |
| Hong et al. | A Novel Control Method of Maximum Efficiency Point Tracking for Series-Series Wireless Power Transfer System |
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 |