CN105141139A - Local communication network (LCL) structure for inductive power transfer (IPT) system and parameter design method of LCL structure - Google Patents

Abstract

The invention discloses a local communication network (LCL) structure for an inductive power transfer (IPT) system and a parameter design method of the LCL structure. In a novel LCL, a pair of intercoupled coil windings, namely a first winding LA and a second winding LB, is arranged, wherein the two windings can be connected with each other by a dotted terminal, and can also be connected with each other by a heteronymous terminal; different constant-current conditions and in-phase conditions can be analyzed by different connection modes; and these conditions are related to the coefficient of mutual induction between the first winding LA and the second winding LB besides component parameters, so that these novel LCL network topological structures are applied to the IPT system; the condition that the current of a primary transmitting coil is not affected by load can be ensured; the difficulty for selecting various component parameters in the circuit can also be lowered; and when the parameter of one component cannot reach the requirements, the parameters of other components can be adjusted by changing the coefficient of mutual induction between the first winding LA and the second winding LB. Therefore, the overall system is still kept in constant-current conditions and in-phase conditions.

Description

For LCL network configuration and the Parameters design thereof of IPT system

Technical field

The present invention relates to induction electric energy transmission (InductivePowerTransfer, IPT) technology, specifically, is a kind of LCL network configuration for IPT system and Parameters design thereof.

Background technology

Induction electric energy transmission (InductivePowerTransfer) technology, referred to as IPT technology, is a kind of technology realizing delivery of electrical energy by means of electromagnetic field of high frequency, is subject to the extensive concern of scholar in recent years.

In IPT system, owing to there is air gap between the former and deputy limit of system, therefore, the general efficiency of transmission adopting the mode of high-frequency resonant to improve system capacity.The former and deputy limit of traditional IPT system adopts single-stage LC resonant network to carry out the transmission of energy usually.But in this mode of resonance IPT system, secondary load can introduce larger reflected umpedance in the LC resonant tank of former limit, make the Sofe Switch operating frequency on former limit very responsive to load variations, even there will be multicycle working point phenomenon, system cloud gray model is unstable, and when system power increases, former limit switching tube can bear very large voltage, current stress.

In order to overcome the output current shortcoming very responsive to load variations, someone proposes and uses LCL network configuration, and traditional LC L network has the characteristic that output current has nothing to do with load, is well suited for the former limit network for IPT system, make former edge emitting coil current constant, not by the impact of load.But find in actual use, this network application, when IPT system former limit circuit, has the shortcomings such as inverter output current higher harmonic components is comparatively large, parameter designing is dumb.

Summary of the invention

Based on above-mentioned defect, first the present invention proposes a kind of LCL network configuration for IPT system, on the basis of traditional LC L network, set up the winding intercoupled for a pair, reduced the difficulty of circuit devcie parameter type selecting by the coefficient of mutual inductance between adjustment coupling winding.

In order to achieve the above object, concrete technical scheme of the present invention is:

For a LCL network configuration for IPT system, its key is, comprises following six kinds of topological form, is specially:

A, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through electric capacity L _abe connected on described second input;

B, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through electric capacity C _pbe connected on described second input;

C, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

D, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

E, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, the first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected;

F, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected.

Based on above-mentioned six kinds of novel LCL network configurations, can find, in LCL network, have the coil windings intercoupled for a pair, i.e. the first winding L _awith the second winding L _b, Same Name of Ends can be adopted to connect between two windings, different name end also can be adopted to connect, and different connected modes can analyze different constant current conditions and in-phase conditions, these conditions except relevant to components and parts inherent parameters, also with the first winding L _awith the second winding L _bbetween coefficient of mutual inductance be correlated with, therefore, these novel LCL network topology structures are applied in IPT system, except former edge emitting coil current can be ensured not by load effect, the difficulty of each component parameter type selecting in circuit can also be reduced, when the parameter of a certain components and parts cannot reach requirement, change first winding L can be passed through _awith the second winding L _bbetween coefficient of mutual inductance adjust the parameter of other components and parts, make whole system still keep constant current conditions and in-phase conditions.

On the basis of above-mentioned various circuit topological structure, the invention allows for a kind of Parameters design of the LCL network configuration for IPT system, specifically carry out according to following steps:

Step 1: given parameters: comprise and send coil current value I _{p, set}, system angle frequencies omega, input voltage U _dCand transmitting coil inductance value L _p, according to calculate the inductance value of the first inductance in general T-shaped three port LCL networks;

Step 2: the inductance value L judging the first inductance ₁whether be greater than transmitting coil inductance value L _p, if so, then select a kind of topological form in a, b, c, e or f; Otherwise enter step 3;

Step 3: the inductance value L judging the first inductance ₁whether be less than transmitting coil inductance value L _p, if so, then select a kind of topological form in d or e, otherwise, select this topological form of e;

Step 4: setting coupling coefficient K ₁, described coupling coefficient K ₁be less than 0.5, transmitting coil L during constant current conditions, constant current according to Different L CL network configuration _pcurrent formula and in-phase conditions calculate the first winding L _a, the second winding L _b, electric capacity C _psize, then according to the first winding L of gained _a, the second winding L _bvalue calculate mutual inductance value M ₁size, described mutual inductance value M ₁computing formula be $M_1=K_1\sqrt{L_A\·L_B};$

Step 5: the first winding L of step 4 gained _a, the second winding L _b, electric capacity C _pand mutual inductance value M ₁whether can realize, if can realize, then design; Otherwise change coupling coefficient K ₁or network topology type, return step 4 and recalculate new parameter value.

By the method, can for the LCL network configuration of different a kind of the bests of IPT Systematic selection, by adjusting the first winding L _awith the second winding L _bbetween coupling coefficient K ₁, transmitting coil L during constant current formula, constant current then according to LCL network configuration _pcurrent formula and in-phase conditions formula, calculate the first winding L _a, the second winding L _band mutual inductance value M ₁value, can then in conjunction with the situation that realize in reality, cycle calculations, finally can obtain best design parameter, reduce the difficulty of circuit design and parameter type selecting.

Remarkable result of the present invention is: by the improvement to traditional LC L network configuration, the various novel LCL network configuration designed, the coil windings intercoupled is introduced in traditional LCL network, when making circuit design, the difficulty during parameter type selecting of circuit components can be reduced by the coupling coefficient between adjustment coupling coil, parameter designing is carried out according to concrete method for designing, the stable operation of different scene IPT system can be met, under the prerequisite ensureing the constant current of former edge emitting coil, homophase, greatly reduce design cost.

Accompanying drawing explanation

Fig. 1 is six kinds of new LCL-type network topology forms of the present invention;

Fig. 2 is the equivalent circuit diagram of a form LCL network topology in Fig. 1;

Fig. 3 is the T-shaped impedance model of three ports of Fig. 2;

Fig. 4 is traditional LCL network topology structure;

Fig. 5 is the flow chart of Parameters design of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention and operation principle are described in further detail.

As shown in Figure 1, a kind of LCL network configuration for IPT system, comprises following six kinds of topological form, is specially:

A, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through electric capacity L _abe connected on described second input;

B, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through electric capacity C _pbe connected on described second input;

C, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

D, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

E, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, the first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected;

F, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected.

The network topology structure of a is example in the form, according to basic circuit principle, when system is issued to stable state in a certain operating frequency, a pair coupling inductance can replace by three discrete inductance, therefore can obtain the equivalent circuit diagram shown in Fig. 2.

Next can to derive the constant current conditions of new LCL-type network and in-phase conditions, to analyze with the T-shaped impedance model of three ports shown in Fig. 3,

This network is a kind of mode of resonance impedance-admittance converter, AC constant voltage source can be converted to AC constant-current source.According to Stable State of Sine model, i can be derived ₃with U _irelation.

$i_3=\frac{X_2}{(X_1+X_2)\·X_2-{X_2}^2+(X_1+X_2)\·(X_3+Z_o)}\·U_i$

Obviously can be found out by above formula, work as X ₁+ X ₂when=0, the output current i of this network ₃with load Z _oirrelevant.Now, above formula is reduced to:

Generally, the fundamental harmonic wave of resonant network input voltage and electric current needs homophase, to eliminate the reactive power of first-harmonic, improves the through-put power of whole system.In order to realize above object, we are deduced the circuit input impedance under fundamental harmonic wave:

$Z_{in,fun}=\frac{{X_2}^2\·\left\{\mathrm{Re}\left(Z_O\right)-j\[X_2+X_3+\mathrm{Im}\left(Z_O\right)\]\right\}}{{\[\mathrm{Re}\left(Z_O\right)\]}^2+{\[X_2+X_3+\mathrm{Im}\left(Z_O\right)\]}^2}$

If X ₂+ X ₃+ Im (Z _o)=0, the input impedance so under fundamental harmonic wave will be purely resistive.Now, the fundametal compoment of input voltage and electric current is homophase.

Therefore, at Im (Z _ounder the prerequisite of)=0, the condition that constant current and in-phase conditions meet simultaneously is: X ₁=X ₃=-X ₂.

According to above analysis, by X ₁, X ₂, X ₃respectively replace by the counter element in the new LCL-type being proposed network, wherein load impedance Z _orepresent reflected umpedance Z _r.Constant current and the in-phase conditions of proposed various forms of new LCL-type networks can be derived thus, as shown in the table.

Table 1 six kinds of new LCL-type topological form correlation formulas

Can find out based on above-mentioned analysis, for the traditional LC L network topology structure shown in Fig. 4, when meeting transmitting coil electric current, the constant current conditions of system and in-phase conditions can be realized by the parameter value adjusting coupling coefficient between coupling inductance and components and parts simultaneously, therefore, when parameter designing, some can be selected to hold facile components and parts to realize, reduce the difficulty of system.

As shown in Figure 5, when specific design, can carry out according to following steps:

Step 1: given parameters: comprise and send coil current value I _{p, set}, system angle frequencies omega, input voltage U _dCand transmitting coil inductance value L _p, according to calculate the inductance value of the first inductance in general T-shaped three port LCL networks;

Step 2: the inductance value L judging the first inductance ₁whether be greater than transmitting coil inductance value L _p, if so, then select a kind of topological form in a, b, c, e or f; Otherwise enter step 3;

Step 3: the inductance value L judging the first inductance ₁whether be less than transmitting coil inductance value L _p, if so, then select a kind of topological form in d or e, otherwise, select this topological form of e;

Step 4: setting coupling coefficient K ₁, described coupling coefficient K ₁be less than 0.5, transmitting coil L during constant current conditions, constant current according to Different L CL network configuration _pcurrent formula and in-phase conditions calculate the first winding L _a, the second winding L _b, electric capacity C _psize, then according to the first winding L of gained _a, the second winding L _bvalue calculate mutual inductance value M ₁size, described mutual inductance value M ₁computing formula be $M_1=K_1\sqrt{L_A\·L_B};$

Step 5: the first winding L of step 4 gained _a, the second winding L _b, electric capacity C _pand mutual inductance value M ₁whether can realize, if can realize, then design; Otherwise change coupling coefficient K ₁or network topology type, return step 4 and recalculate new parameter value.

By the method, in conjunction with different LCL network configurations, select coupling coefficient K ₁, transmitting coil L during constant current formula, constant current according to LCL network configuration _pcurrent formula and in-phase conditions formula, calculate the first winding L _a, the second winding L _band mutual inductance value M ₁value, can then in conjunction with the situation that realize in reality, cycle calculations, until obtain best design parameter, finally reaches effect of the present invention.

Claims (2)

1. for a LCL network configuration for IPT system, it is characterized in that, comprise following six kinds of topological form, be specially:

A, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through electric capacity L _abe connected on described second input;

B, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band transmitting coil L _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through electric capacity C _pbe connected on described second input;

C, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

D, between first input end and the second input, be in series with the first winding L successively _a, the second winding L _band electric capacity C _p, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected, described first winding L _awith the common port of the second winding also through transmitting coil L _pbe connected on described second input;

E, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, the first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts Same Name of Ends to be connected;

F, between first input end and the second input, be in series with the first inductance L successively ₁, the first winding L _aand electric capacity C _p, the first inductance L ₁with the first winding L _acommon port be also connected in series the second winding L successively _bwith transmitting coil L _pafter connect described second input, described first winding L _awith the second winding L _bbe the coupling inductance that intercouples for a pair and the common port of the two adopts different name end to be connected.

2., as claimed in claim 1 for LCL network configuration and the Parameters design of IPT system, it is characterized in that carrying out according to following steps:

Step 1: given parameters: comprise and send coil current value I _{p, set}, system angle frequencies omega, input voltage U _dCand transmitting coil inductance value L _p, according to calculate the inductance value of the first inductance in general T-shaped three port LCL networks;

Step 2: the inductance value L judging the first inductance ₁whether be greater than transmitting coil inductance value L _p, if so, then select a kind of topological form in a, b, c, e or f; Otherwise enter step 3;

Step 3: the inductance value L judging the first inductance ₁whether be less than transmitting coil inductance value L _p, if so, then select a kind of topological form in d or e, otherwise, select this topological form of e;

Step 4: setting coupling coefficient K ₁, described coupling coefficient K ₁be less than 0.5, transmitting coil L during constant current conditions, constant current according to Different L CL network configuration _pcurrent formula and in-phase conditions calculate the first winding L _a, the second winding L _b, electric capacity C _psize, then according to the first winding L of gained _a, the second winding L _bvalue calculate mutual inductance value M ₁size, described mutual inductance value M ₁computing formula be $M_1=K_1\sqrt{L_A\·L_B};$

Step 5: the first winding L of step 4 gained _a, the second winding L _b, electric capacity C _pand mutual inductance value M ₁whether can realize, if can realize, then design; Otherwise change coupling coefficient K ₁or network topology type, return step 4 and recalculate new parameter value.