CN103166329B - Bifurcation frequency transfer control circuit in inductive power transfer (IPT) system and control method thereof - Google Patents

Abstract

The invention discloses a bifurcation frequency transmission control circuit and a control method thereof in an IPT system. The circuit includes a power supply module, a switch network, a primary side resonance compensation circuit, a transmitting coil, a receiving coil, a secondary side resonance compensation circuit and a load. The method is that a delay interference module is connected to the controller, and the controller controls the working state of the switch network according to the delay interference signal output by the delay interference module and the zero-crossing signal output by the zero-crossing detection circuit. Its remarkable effect is: simple circuit structure, convenient control, no need to add additional circuits to the main circuit, only need to add timely delay interference to the detection feedback signal, through the design of the bifurcation frequency transmission control in this IPT system The circuit and the specific control method of the circuit enable the phase trajectory flow of the system to converge to a specified stable limit cycle attractor, thereby improving the stability and reliability of the IPT system.

Description

Bifurcation Frequency Transmission Control Circuit and Control Method in IPT System

technical field

The present invention relates to inductive power transfer technology (Inductive Power Transfer, referred to as IPT), specifically, a bifurcation frequency transmission control circuit in an IPT system and a control method thereof.

Background technique

Inductive Power Transfer (IPT for short) is a new power transmission technology that uses high-frequency electromagnetic fields as energy carriers to wirelessly transmit electric energy from the power supply to the load in the form of magnetic energy. This technology has the advantages of safety, reliability and flexibility, and has broad application prospects in the fields of biomedical electronics, rail transit, electric vehicles, consumer electronics, etc., and has become one of the research hotspots in the field of power electronics.

As shown in Figure 1, from the perspective of system structure, the IPT system includes two parts, the primary side and the secondary side. The electric energy is output to the load after reactive power compensation and energy conversion. The particularity and complexity of the structure lead to the typical high-order nonlinear characteristics of the system, which leads to complex dynamic behavior and increases the difficulty of system modeling, analysis and control.

Literature research shows that in the IPT system, when system parameters such as mutual inductance, primary and secondary side resonance network parameters, and load impedance change, the bifurcation of the system resonance frequency may be caused. In the bifurcation area, it is reflected that there are three resonance frequencies in the system, two of which have autonomous oscillation stability, and the other does not have autonomous oscillation stability, and the frequency value is located between the two stable frequency values. For the research on the frequency bifurcation phenomenon of the non-contact power transmission system, please refer to the paper published in "New Technology of Electrical Engineering and Power", Vol. University of Electrical Engineering, Han Teng, Zhuo Fang, et al.

To sum up, the defect of the existing technology is that after the system enters the frequency bifurcation area with more than one stable resonance frequency with the change of parameters, which bifurcation frequency it will work at has a certain degree of randomness. The method is used to realize the dynamic transport control of the phase trajectory of the limit cycle attractor corresponding to the specified frequency, which leads to problems such as unstable transmission efficiency of the system.

Contents of the invention

In order to overcome the above defects, the present invention provides a branch frequency transmission control circuit and its control method. The transmission control parameters are set for each resonance frequency point, and then the IPT system can be controlled in the same way as changing channels of a TV set. Freely switch between multiple stable resonance frequency points.

In order to achieve the above object, the specific technical scheme adopted in the present invention is as follows:

A bifurcation frequency transmission control circuit in an IPT system, including a power supply module, a switch network, a primary side resonance compensation circuit, a transmitting coil, a receiving coil, a secondary side resonance compensation circuit and a load, the key lies in: the primary side resonance compensation A zero-crossing detection circuit is connected to the circuit, the output end of the zero-crossing detection circuit is connected to a controller, the output end of the controller is connected to the switch network through a drive circuit, and a delay interference is connected to the controller module, and the controller controls the working state of the switching network according to the delayed interference signal output by the delayed interference module and the zero-crossing signal output by the zero-crossing detection circuit.

In combination with the above-mentioned system structure, the present invention also proposes a control method for the bifurcation frequency transmission control circuit in the IPT system, specifically according to the following steps:

Step 1: Determine the two stable bifurcation frequencies of the IPT system as f ₁ and f ₂ , and f ₁ <f ₂ ;

Step 2: Set two delayed interference signals, namely the first delayed interference signal (δ ₁ , T _d1 ) and the second delayed interference signal (δ ₂ , T _d2 ), where δ ₁ is the first delayed interference signal signal delay time and T _d1 is the duration of the first delayed interference signal, δ ₂ is the delay time of the second delayed interference signal and T _d2 is the duration of the second delayed interference signal.

Step 3: If the IPT system needs to be controlled from the stable bifurcation frequency f ₁ to f ₂ , the delay interference module outputs the first delay interference signal (δ ₁ , T _d1 ) to the controller; if the IPT When the system needs to be controlled from the stable bifurcation frequency f ₂ to f ₁ , the delay interference module outputs a second delay interference signal (δ ₂ , T _d2 ) to the controller;

Step 4: when there is no interference signal, the control signal output by the controller and the zero-crossing signal output by the zero-crossing detection circuit have the same frequency and phase;

When the controller receives the first delayed interference signal (δ ₁ , T _d1 ), the output control signal is a signal in which the zero-crossing signal is delayed by δ ₁ , and the duration of the delayed interference is T _d1 , When the duration T _d1 ends, the control signal is restored to the same frequency and phase as the zero-crossing signal;

When the controller receives the second delayed interference signal (δ ₂ , T _d2 ), the output control signal is a signal in which the zero-crossing signal is delayed by δ ₂ , and the duration of the delayed interference is T _d2 , When the duration T _d2 ends, the control signal is restored to have the same frequency and phase as the zero-crossing signal.

As a further description, when the primary side resonance compensation circuit (3) and the secondary side resonance compensation circuit (4) are both series resonance circuits, follow the steps below to determine the two stable bifurcation frequencies f ₁ and f ₂ of the IPT system:

Step 1-1: Build the equation $\left\{\begin{array}{c}\mathrm{Px}*\left(T\right)=0\\ \mathrm{Pf}(\mathrm{\&tau;},x*)\&NotEqual;0,\mathrm{\&tau;}\&Element;(0,\frac{T}{2})\end{array}\right.,$ in:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; A</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; BE</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}\\ \mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ]</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; BE</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; At</span>}}\end{array}\right.$

And P is the projection matrix, A and B are the system coefficient matrices, I is the identity matrix with the same order as A, E _dc is the output voltage of the power module, x is the system state vector, and x* is the period of the system state vector x move point, and have:

x=[i _p ,u _p ,i _s ,u _s ] ^T ;

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\\ \frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \frac{{\mathrm{<span\; class="notranslate">\; MR</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccc}\frac{<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

P=[1 0 0 0]

Among them, _ip is the resonant current of the primary side, _up is the resonant voltage of the primary side, is the resonant current of the secondary side, _{u s} is the resonant voltage of the secondary side, L _p is the point inductance value of the transmitting coil, and R _p is the equivalent value of the transmitting coil Resistance value, C _p is the compensation capacitance value of the primary side, L _s is the inductance value of the receiving coil, R _s is the equivalent resistance value of the receiving coil, C _s is the compensation capacitance value of the secondary side, R _L is the load resistance value, M is the transmitting coil The mutual inductance value with the receiving coil;

Step 1-2: According to the above equation, the three roots of the bifurcation area of the system are T ₁ , T', T ₂ and T ₁ >T'>T₂;

Step 1-3: Determine the stable bifurcation frequency from the three roots in Step 1-2 $f_2=\frac{1}{T_2}.$

Preferably, the duration of the first delayed interference signal The duration of the second delayed interference signal

The remarkable effect of the present invention is: the circuit structure is simple, the control is convenient, no additional circuit needs to be added to the main circuit, only an appropriate delay interference needs to be added to the detection feedback signal, and by designing the bifurcation frequency in this IPT system The transmission control circuit and the specific control method of the circuit enable the phase trajectory flow of the system to converge to the specified stable limit cycle attractor, thereby improving the stability and reliability of the IPT system.

Description of drawings

Figure 1 is the main circuit diagram of the IPT system with the primary and secondary sides both in series resonance;

Fig. 2 is a system block diagram of the present invention;

Fig. 3 is a sequence diagram of control signals of the present invention;

Fig. 4 is a system oscillation frequency response curve of a specific embodiment.

Detailed ways

The specific implementation manner and working principle of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, a bifurcation frequency transmission control circuit in an IPT system includes a power module 1, a switch network 2, a primary side resonance compensation circuit 3, a transmitting coil, a receiving coil, and a secondary side resonance compensation circuit 4 As well as the load, the primary-side resonance compensation circuit 3 is connected with a zero-crossing detection circuit 5, which is mainly used to detect the primary-side resonance current _ip , and the output terminal of the zero-crossing detection circuit 5 is connected with a controller 6, and the controller 6 The output end of the drive circuit 7 is connected with the switch network 2, and the controller 6 is also connected with a delay interference module 8, and the controller 6 is outputted according to the delay interference signal and the delay interference signal of the delay interference module 8. The zero-crossing signal output by the zero detection circuit 5 controls the working state of the switching network 2 .

In combination with the above circuit structure, the present invention also proposes a control method for the bifurcation frequency transmission control circuit in the IPT system, specifically according to the following steps:

Step 1: Determine the two stable bifurcation frequencies of the IPT system as f ₁ and f ₂ , and f ₁ <f ₂ ;

Step 2: Set two delayed interference signals, namely the first delayed interference signal (δ ₁ , T _d1 ) and the second delayed interference signal (δ ₂ , T _d2 ), where δ ₁ is the first delayed interference signal signal delay time and T _d1 is the duration of the first delayed interference signal, δ ₂ is the delay time of the second delayed interference signal and T _d2 is the duration of the second delayed interference signal.

Step 3: If the IPT system needs to be controlled from the stable bifurcation frequency f ₁ to f ₂ , the delay interference module 8 outputs the first delay interference signal (δ ₁ , T _d1 ) to the controller 6; If the IPT system needs to be controlled from the stable branch frequency f ₂ to f ₁ , the delay interference module 8 outputs a second delay interference signal (δ ₂ , T _d2 ) to the controller 6;

Step 4: When there is no interference signal, the control signal output by the controller 6 and the zero-crossing signal output by the zero-crossing detection circuit 5 have the same frequency and phase;

When the controller 6 receives the first delayed interference signal (δ ₁ , T _d1 ), the output control signal is a signal in which the zero-crossing signal is delayed by δ ₁ time length, and the duration of the delayed interference is T _d1 , when the duration T _d1 ends, the control signal is restored to the same frequency and phase as the zero-crossing signal;

When the controller 6 receives the second delayed interference signal (δ ₂ , T _d2 ), the output control signal is a signal in which the zero-crossing signal is delayed by δ ₂ in length, and the duration of the delayed interference is T _d2 , when the duration T _d2 ends, the control signal is restored to the same frequency and phase as the zero-crossing signal. Combined with what is shown in FIG. 3 , it can be clearly seen that the interference effect of the delayed interference signal on the control signal.

In the specific implementation process, the two stable bifurcation frequencies f ₁ and f ₂ of the IPT system are determined according to the following steps. In this example, only the primary side resonance compensation circuit 3 and the secondary side resonance compensation circuit 4 shown in Figure 1 are connected in series. The IPT system of the resonant circuit is analyzed, and the specific steps are as follows:

Step 1-1: Build the equation $\left\{\begin{array}{c}\mathrm{Px}*\left(T\right)=0\\ \mathrm{Pf}(\mathrm{\&tau;},x*)\&NotEqual;0,\mathrm{\&tau;}\&Element;(0,\frac{T}{2})\end{array}\right.,$ in:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; A</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; BE</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}\\ \mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ]</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; BE</span>}}_{\mathrm{<span\; class="notranslate">\; dc</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; At</span>}}\end{array}\right.$

And P is the projection matrix, A and B are the system coefficient matrices, I is the identity matrix with the same order as A, E _dc is the output voltage of the power module 1, x is the system state vector, and x* is the period of the system state vector x Fixed point, and have:

x=[i _p ,u _p ,i _s ,u _s ] ^T ;

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}\frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\\ \frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \frac{{\mathrm{<span\; class="notranslate">\; MR</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \frac{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccc}\frac{<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}& \mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

P=[1 0 0 0]

Among them, _ip is the resonant current of the primary side, u _p is the resonant voltage of the primary side, i _s is the resonant current of the secondary side, u _s is the resonant voltage of the secondary side, L _p is the point inductance value of the transmitting coil, and R _p is the equivalent resistance of the transmitting coil C _p is the compensation capacitance value of the primary side, L _s is the inductance value of the receiving coil, R _s is the equivalent resistance value of the receiving coil, C _s is the compensation capacitance value of the secondary side, R _L is the load resistance value, M is the transmission coil and For the mutual inductance value between the receiving coils, for the voltage-type topology structure of the primary side resonance compensation circuit 3 and the secondary side resonance compensation circuit 4, it is only necessary to change the above equations and each of the system coefficient matrices A and B. expression, and other control steps and working principles are the same as in this embodiment;

Step 1-2: According to the above equation, it can be solved that the three roots of the system in the bifurcation region are T ₁ , T', T ₂ and T ₁ >T'> T ₂ , according to the references listed in the background technology can also be It can be seen that the three roots T ₁ , T', T ₂ of the system in the bifurcation region correspond to two stable frequencies and one unstable frequency respectively, and the unstable frequency is between the two stable frequencies;

Step 1-3: So two stable bifurcation frequencies can be determined according to the three roots in step 1-2 $f_1=\frac{1}{T_1},$ $f_2=\frac{1}{T_2}.$

Due to the wide value range of the duration of the delayed interference signal, in order to ensure that the system re-enters another stable state from one stable state, preferably, the duration of the first delayed interference signal The duration of the second delayed interference signal

Considering a specific IPT system, the values of the system parameters are shown in Table 1, and the resonance operating point of the system can be obtained according to the system equations established by the system, as shown in Table 2. According to the two stable bifurcations obtained in Table 2 The frequency value of the frequency point can set the delay time δ ₁ of the first delayed interference signal (δ ₁ , T _d1 ) to 15 μs, the duration time T _d1 is set to 500 μs, and the second delayed interference signal (δ ₂ , T The delay time δ ₂ of _d2 ) is 5 μs, and the duration T _d2 is set to 500 μs. The IPT system is controlled according to the above parameters and control steps, and the oscillation frequency response curve shown in Fig. 4 can be obtained.

From the analysis in Figure 4, it can be seen that after the system starts to enter a steady state, it works at the resonance point 3, and its autonomous oscillation frequency is 48.08kHz. When the time-delay interference signal is added, the system oscillation frequency changes significantly, and is quickly adjusted from 48.08kHz to 64.52kHz, after the time-delay interference ends, the system autonomous oscillation frequency converges to 63.25kHz, the system operating point shifts to resonance point 1, and the resonance frequency is controllable to ensure the stability and reliability of the system.

Table 1 Series resonant IPT system parameter list

Table 2 Resonant operating point of series resonant IPT system

Claims (3)

1. the control method of the fork frequency pipage control circuit in an IPT system, its circuit comprises power module (1), switching network (2), former limit resonance compensation circuit (3), transmitting coil, receiving coil, secondary resonance compensation circuit (4) and load, on described former limit resonance compensation circuit (3), be connected with zero cross detection circuit (5), the output of this zero cross detection circuit (5) is connected with controller (6), the output of this controller (6) is connected with described switching network (2) through overdrive circuit (7), on described controller (6), be also connected with time delay interference module (8), it is characterized in that this circuit controls according to following steps:

Step 1: two stable fork frequencies determining IPT system are f ₁and f ₂, and f ₁< f ₂;

Step 2: two kinds of time delay interference signals are set, are respectively the first time delay interference signal (δ ₁, T _d1) and the second time delay interference signal (δ ₂, T _d2), wherein δ ₁be the first time delay interference signal delay time and t _d1be the duration of the first time delay interference signal, δ ₂be the second time delay interference signal delay time and t _d2it is the duration of the second time delay interference signal;

Step 3: if IPT system need to be from stable fork frequency f ₁control to f ₂time, by described time delay interference module (8) output the first time delay interference signal (δ ₁, T _d1) in described controller (6); If IPT system need to be from stable fork frequency f ₂control to f ₁time, by described time delay interference module (8) output the second time delay interference signal (δ ₂, T _d2) in described controller (6);

Step 4: do the used time in state no interference signal, the zero cross signal of the control signal of described controller (6) output and described zero cross detection circuit (5) output is with frequency homophase;

When controller (6) receives the first time delay interference signal (δ ₁, T _d1) time, the control signal of output is described zero cross signal hysteresis δ ₁the signal of time span, and the duration of time delay interference effect be T _d1, work as duration T _d1when end, described control signal reverts to described zero cross signal with frequency homophase again;

When controller (6) receives the second time delay interference signal (δ ₂, T _d2) time, the control signal of output is described zero cross signal hysteresis δ ₂the signal of time span, and the duration of time delay interference effect be T _d2, work as duration T _d2when end, described control signal reverts to described zero cross signal with frequency homophase again.

2. the control method of the fork frequency pipage control circuit in IPT system according to claim 1, it is characterized in that: in the time that former limit resonance compensation circuit (3) and secondary resonance compensation circuit (4) are series resonant tank, determine in accordance with the following steps two stable fork frequency f of IPT system ₁and f ₂:

Step 1-1: set up equation wherein:

And P is projection matrix, A, B are coefficient of combination matrix, and I is and the unit matrix of A with exponent number, E _dcfor the output voltage of power module (1), x is system mode vector, and x* is the period fixed point of system mode vector x, and has:

x＝[i _p,u _p,i _s,u _s] ^T；

P＝[1?0?0?0]

Wherein, i _pfor former limit resonance current, u _pfor former limit resonance potential, i _sfor secondary resonance current, u _sfor secondary resonance potential, L _pfor transmitting coil inductance value, R _pfor transmitting coil equivalent resistance, C _pfor former limit building-out capacitor value, L _sfor receiving coil inductance value, R _sfor receiving coil equivalent resistance, C _sfor secondary building-out capacitor value, R _lfor load resistance value, M is the mutual inductance value between transmitting coil and receiving coil;

Step 1-2: three roots that solve system fork region according to above-mentioned equation are T ₁, T', T ₂and T ₁> T'> T ₂;

Step 1-3: determine stable fork frequency according to three roots in step 1-2

3. the control method of the fork frequency pipage control circuit in IPT system according to claim 1, is characterized in that: the duration of described the first time delay interference signal the duration of described the second time delay interference signal