CN108306419B - Electric field type wireless power transmission system with multi-transmitting single-receiving structure - Google Patents

Abstract

The invention discloses an electric field type wireless power transmission system with a multi-transmitting single-receiving structure, comprising a plurality of transmitting ends and a receiving end, the transmitting end includes a current source, a compensation circuit and a transmitting end plate, and the receiving end includes a receiving end plate , compensation circuit, rectification filter circuit and load; a plurality of transmitting end plates are placed on the receiving end plates. The beneficial effect of the present invention is that the transmitting ends are connected in parallel and the input current is kept in the same phase, the total input current is increased, the input power is increased, and the system transmission power is improved. At the same time, the input end is connected to a compensation circuit to make multiple transmitter ends in a resonant state, so that the system transmits active power and has high stability. The shape of the receiving end plate is rectangle, circle, regular polygon, etc., which makes the system application range not limited.

Description

An electric field wireless power transmission system with multiple transmitters and single receivers

technical field

The invention relates to the technical field of high-frequency electric field coupling wireless power transmission, in particular to an electric field type wireless power transmission system with a multi-transmitting single-receiving structure.

Background technique

Wireless power transmission technology is a new type of power transmission technology. In high-power applications, the most used method is electromagnetic coupling. IPT technology can avoid safety hazards such as catenary or third rail derailment, and get rid of electrical The bondage of equipment contact, but it also has some shortcomings, such as: the use of high-cost high-frequency litz wires, the need to use high-frequency ferrite materials to guide the magnetic field, which increases the weight of the transmit-receive coupling device, and the leaked magnetic field will Eddy current losses are generated around metal objects, limiting the range of IPT use. Therefore, in recent years, CPT (electric field coupled wireless power transfer technology), which is a working mode of IPT duality, has attracted much attention and research.

Electric field-coupled wireless power transmission does not generate eddy current heating near metal objects, and uses cheaper aluminum plates or copper plates for energy transmission, which can save costs. It can be seen that the electric field wireless power transmission has broad development prospects. The traditional electric field type wireless power transmission input terminal only contains a single inverter, which is limited by the capacity and price of the switching device, so the transmission power of the system is limited. Increase the system operating frequency or the voltage between the plates to increase the transmission power. Therefore, it is necessary to realize the increase of the total input current by paralleling multiple low-power high-frequency inverters under the existing capacity level of the switching device, so as to increase the input power, thereby improving the transmission power of the CPT system, and at the same time improving the system redundancy. Compared with single-channel transmission, multi-channel transmission can reduce the voltage stress on the emitter plate and improve the security of the system under the condition of transmitting the same active power.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an electric field type wireless power transmission system with a multi-transmitting single-receiving structure.

The technical scheme that realizes the object of the present invention is:

An electric field type wireless power transmission system with a multi-transmitting single-receiving structure, characterized in that it includes k transmitting ends and one receiving end, and k is greater than or equal to 2; among the k transmitting ends, the first transmitting end includes a current source I _1. Compensation circuit N ₁ , emitter plate P ₁ and emitter plate P ₂ , the output end of the current source I ₁ is connected to the input end of the compensation circuit N ₁ , and one end of the output end of the compensation circuit N ₁ is connected to the plate P ₁ , the other end is connected to the plate P ₂ ; the second emitting end includes a current source I ₂ , a compensation circuit N ₂ , an emitter plate P ₃ and an emitter plate P ₄ , and the output end of the current source I ₂ is connected to The input end of the compensation circuit N ₂ and the output end of the compensation circuit N ₂ are connected to the plate P ₃ at one end and connected to the plate P ₄ at the other end; and so on, the kth emitter end includes the current source I _k and the compensation circuit N _k , the emitter plate P _2k-1 and the emitter plate P _2k , the output end of the current source I _k is connected to the input end of the compensation circuit N _k , and one end of the output end of the compensation circuit N _k is connected to the plate P _2k-1 , the other end is connected to the pole plate P _2k ; the receiving end includes the receiving end pole plate P _2k+1 , the receiving end pole plate P _2k+2 , the compensation circuit N _k+1 , the rectifying filter circuit P and the load _RL ; The plates P _2k+1 and P _2k+2 are respectively connected to the input end of the compensation circuit N _{k+1 ,} and the output end of the compensation circuit N k+ ₁ is connected to the load _RL through the rectifying and filtering circuit P; P ₃ , . . . , P _{2k-1 are} placed on the receiving end plate P _{2k+1 , and} P ₂ , P ₄ , _. , N _k and N _k+1 are all CLC'-π structures.

Further, the transmitting end plates P ₁ , P ₂ , P ₃ , P ₄ . . . , P _2k-1 and P _2k have the same shape, and the receiving end plates P _2k+1 and P _2k+2 have the same shape; P ₁ , P ₃ , ..., P _2k-1 are placed on P _2k+1 at equal distances in sequence, P ₂ , P ₄ , ..., P _2k are placed on P _2k+2 at equal distances in sequence, P ₁ , P ₃ , ..., P _{2k-1 corresponds to} the placement positions of P ₂ , P ₄ , . P _2k+2 , and its board surfaces are in the same plane. In this technical solution,

In the previous technical solution; the transmitting end plate and the receiving end plate are both rectangular, and the transmitting end plate is placed on the receiving end plate along the long side of the rectangle; the long sides of the receiving end plate are parallel to each other, on the same side. The short side is in a straight line. Alternatively, the transmitting end plate is rectangular, the receiving end plate is circular, and the transmitting end plate is placed on the receiving end plate around the center of the circle. Alternatively, the transmitting end plate is rectangular, the receiving end plate is a regular polygon, and the transmitting end plate is placed on the receiving end plate around the center of the regular polygon.

Further, the transmitting end plate and the receiving end plate are curved surfaces corresponding to each other.

Further, the receiving end plate is a sphere, and the transmitting end plate is a corresponding curved surface.

The beneficial effect of the present invention is that,

1. The (2k+2) plates are equivalent to (k+1) port networks, of which 1, 2, 3...k ports are used as transmitters, and (k+1) ports are used as receivers. Parallel connection and keep the input current in the same phase, increase the total input current, increase the input power, and improve the system transmission power.

2. The mutual influence between the k input terminals is reduced by the parallel CLC' compensation structure of the current source, and the circuit is in a resonant state, the system output is all active power, and it is maintained in a stable state.

3. The system can effectively improve the output power of the CPT system under the condition of switching devices of the same capacity, and at the same time, the transmission efficiency is high.

4. The plate voltage stress at the input is reduced while delivering the same power.

5. The shape of the receiving plate can be rectangle, circle, regular polygon, etc., so that the scope of application of the system is not limited.

Description of drawings

Fig. 1 is the structural representation that the receiving pole plate is rectangular;

Fig. 2 is the structural representation that the receiving pole plate is circular;

Fig. 3 receiving pole plate is the structural representation of regular polygon;

Fig. 4 is the structural representation that the receiving polar plate is a sphere or a spherical surface;

Figure 5 is a structural diagram of a capacitor parallel current source with 6 plate capacitors equivalent to 3 ports;

Fig. 6 is the system structure circuit of the three-port six-pole plate;

Figure 7 is a structural diagram of a capacitor parallel current source with (2k+2) plate capacitors equivalent to (k+1) ports;

FIG. 8 is a schematic structural diagram of the CPT system of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 is a structural diagram of (2k+2) plates with a rectangular receiving plate, wherein P ₁ P ₂ , P ₃ P ₄ ... P _2k-1 P _2k plates are used as emitter plates, P _2k+1 P _{2k+ 2} plates are used as receiving plates. And the emitter plates are all square, the side length is l ₁ , and the distances between the emitter plates P ₁ and P ₂ , P ₃ and P ₄ . . . P _2k-1 and P _2k are all l _e1 .

Fig. 2 and Fig. 3 are respectively the circular and regular polygonal structure diagrams of the receiving plates, and the two receiving plates are of the same size.

The emitter plate and the receiver plate can be flat plates or curved plates to meet the different needs of the actual use process. The receiver plate can even be a polyhedron or a sphere, as long as the emitter plate and the receiver plate can form a capacitor. As shown in Figure 4, the receiving plate is spherical or spherical.

Take two transmitters and one receiver as an example.

As shown in Fig. 5 and Fig. 6, the system becomes an electric field coupled wireless power transmission system with double transmitter and single receiver structure, including two connected AC current sources (I ₁ , I ₂ ) and two transmitter compensation circuits in turn. N ₁ (C _P1 , L _P1 , C _E1 ) and N ₂ (C _P2 , L _P2 , C _E2 ), four emitter plates (P ₁ plate, P ₂ plate, P ₃ plate, P ₄ plate), etc. Effective capacitance, two receiving end plates (P ₅ plate, P ₆ plate) equivalent capacitance, receiving end compensation circuit N ₃ (C _E3 , L _S , C _S ), load (R _L ).

The six plates in Fig. 5 are P ₁ , P ₂ , P ₃ , P ₄ , P ₅ , and P ₆ respectively, wherein the P ₁ P ₂ plates and the P ₃ P ₄ plates are used as the emitter plates, and the P ₅ P ₆ plates are used as the emitter plates. For the receiving plate, the six plates are equivalent to the structure diagram of the capacitor parallel current source of the three ports P ₁ P ₂ , P ₃ P ₄ , P ₅ P ₆ , and the equivalent capacitance of the three ports is as follows:

The equivalent current source of the three ports is as follows:

The mutual capacitances C _M12 , C _M23 and C _M13 formed between the two ports are determined by formula (3):

According to the input and output voltage and current relationship between the full-bridge rectifier circuit and the LC filter circuit in series, it can be known that:

Among them, R _ac is the size of the AC impedance, and R _L is the size of the DC load.

After the inductances L _P1 and L _P2 in the transmitter compensation circuit CLC' are determined, the capacitance values of C _P1 , C _P2 and C _E1 and C _E2 can be calculated according to the coupling characteristics, wherein C _P1 and C _P2 are respectively related to L _P1 and L _P2 When the angular frequency is ω, C _E1 is connected in parallel with the equivalent capacitance C ₁ of the P ₁ P ₂ ports, C _E2 is connected in parallel with the equivalent capacitance C ₂ of the P ₃ P ₄ ports, and C _E3 is connected with the equivalent capacitance C of the P ₅ P ₆ ports. ₃ are connected in parallel, the compensation terminal capacitance C _S can be determined by the following formula (5):

The compensation terminal inductance L _S and C _S resonate at the angular frequency ω, and the value of L _S can be obtained:

The expression for output power is:

Among them, I ₁ and I ₂ are the input current sources in FIG. 6 , and I ₃ is the current flowing through the load _RL at the output end. It can be seen from (7) that when I ₁ and I ₂ are in the same phase, the output power P _out is the largest. Therefore, when designing parameters, the input voltage and current should be kept in the same phase to maximize the transmission power.

Figure 7 is a structural diagram of a capacitor parallel current source with (k+1) ports equivalent to (2k+2) plates, wherein the equivalent capacitances of the P ₁ P ₂ ports are C ₁ , P ₃ P ₄ ports, etc. The effective capacitance is C ₂ ,...P _2k+1 The equivalent capacitance of the P _2k+2 port is C _k+1 , and its capacitance value is determined by formula (1):

The equivalent current source of (k+1) ports is as follows:

The mutual capacitances C _M12 , C _M13 , C _M14 ... C _M(k+1)k formed between the two ports are determined by formula (3):

The output power is determined by equation (4):

k=1, 2, 3...K in the above formulas, and C _xy is the size of the capacitor formed by the two pole plates, x and y are the serial numbers of the pole plates, and the size of C _xy is determined by the size of the pole plate and the pole plate. The distance between the boards is determined. C _k is the self-capacitance of the k-th port, {V ₁ , V ₂ . . . V _k+1 } are the voltages of the 1st, 2nd, 3rd...(k+1)th ports, respectively. C _Mxy is the mutual capacitance between the xth port and the yth port. I _xy is the size of the equivalent current source formed between the two pole plates x and y, where x and y are the serial numbers of the pole plates respectively.

When the transmitter current is in the same phase, the output power is the largest, which has the characteristics of high transmission efficiency, high transmission power and good stability.

Fig. 8 is a topology structure of high-power multi-transmit and single-receive, which sequentially includes _k AC current _sources ( _{I 1} , I ₂ . , L _Pk , C _Ek ), 2k emitter plates, 2 receiver plates, receiver compensation circuit C'LC-π type structure N _k+1 (C _E(k+1) , L _S , C _S ), rectifier filter circuit P and load R _L . Consider (2k+2) plates as (k+1) ports, which constitute the equivalent plate capacitances of the transmitter and receiver, AC current sources (I ₁ , I ₂ ... I _k ), which are compensated by the CLC' structure After the circuit, a very high voltage is generated on the plate, thereby forming displacement current transmission power, P ₁ P ₂ , P ₃ P ₄ ... P _(2k-1) P _(2k) as a transmitting port to transmit power to P _{( 2k+1)} P _(2k+2) receiving port, the C'LC-π structure compensation circuit of the receiving end is connected in parallel with the rectifier and filter circuit, and the load is connected after the rectifier. Since the k transmitters will influence each other, parameter design can be used to make both transmitters in a resonant state, so that the system has no reactive power input, and the transmitted power is active power, which improves the stability of the system operation. . The system can effectively improve the output power of the CPT system under the condition of switching devices of the same capacity, and the transmission efficiency is high.

Claims (7)

1. an electric field type wireless power transmission system of a multi-transmitting single-receiving structure is characterized in that, comprising k transmitting ends and a receiving end, and k is greater than or equal to 2; Among the k transmitting ends, the first transmitting end includes a current source I ₁ , a compensation circuit N ₁ , an emitter plate P ₁ and an emitter plate P ₂ , and the output end of the current source I ₁ is connected to the compensation circuit N ₁ One end of the output end of the compensation circuit N ₁ is connected to the plate P ₁ , and the other end is connected to the plate P ₂ ; the second transmitting end includes the current source I ₂ , the compensation circuit N ₂ , the transmitting end plate P ₃ and The emitter electrode plate P ₄ , the output end of the current source I ₂ is connected to the input end of the compensation circuit N ₂ , one end of the output end of the compensation circuit N ₂ is connected to the electrode plate P ₃ , and the other end is connected to the electrode plate P ₄ ; By analogy, the kth transmitting end includes a current source I _k , a compensation circuit N _k , an emitter plate P _2k-1 and an emitter plate P _2k , the output end of the current source I _k is connected to the input end of the compensation circuit N _k , One end of the output end of the compensation circuit N _k is connected to the pole plate P _2k-1 , and the other end is connected to the pole plate P _2k ; the receiving end includes the receiving end plate P _2k+1 , the receiving end plate P _2k+2 , the compensation circuit N _k+1 , rectification filter circuit P and load R _L ; the pole plates P _2k+1 and P _2k+2 are respectively connected to the input end of the compensation circuit N _{k+1 ,} and the output end of the compensation circuit N k+1 is rectified by The filter circuit P is connected to the load _RL ; the transmitting end plates P ₁ , P ₃ , ..., P _2k-1 are placed on the receiving end plate P _2k+1 , and P ₂ , P ₄ , ..., P _2k are placed on P _2k+2 ; the compensation circuits N ₁ , N ₂ , . . . , N _k and N _k+1 are all CLC′-π type structures. 2 . The electric field type wireless power transmission system according to claim 1 , wherein the transmitting end plates P ₁ , P ₂ , P ₃ , P ₄ . . . , P _2k-1 and P _{2k have} the same shape, and receive The terminal plates P _{2k + 1} and P _{2k + 2} are of the same shape; P ₁ , P ₃ , _. Placed on P _2k+2 , P ₁ , P ₃ , ..., P _{2k-1 correspond} to the placement positions of P ₂ , P ₄ , ..., P _2k in sequence _; The plate surface of P _2k-1 is parallel to the plate surface of the receiving end plate P _2k+1 and the distance is equal, and the plate surface of the transmitting end plate P ₂ , P ₄ , ..., P _2k is parallel to the receiving end plate P _{2k +2} and the distances are equal; the receiving end plate P _2k+1 is adjacent to P _2k+2 , and the plates are on the same plane. 3. The electric field type wireless power transmission system according to claim 2, wherein the transmitting end plate and the receiving end plate are both rectangular, and the transmitting end plate is placed on the receiving end plate along the long side of the rectangle. The long sides of the receiving end plate are parallel to each other, and the short sides on the same side are in a straight line. 4. The electric field type wireless power transmission system according to claim 2, wherein the transmitting end plate is rectangular, the receiving end plate is circular, and the transmitting end plate is placed on the receiving end plate around the center of the circle . 5. The electric field type wireless power transmission system according to claim 2, wherein the transmitting end plate is rectangular, the receiving end plate is a regular polygon, and the transmitting end plate is placed at the receiving end around the center of the regular polygon plate. 6 . The electric field type wireless power transmission system according to claim 1 , wherein the transmitting end plate and the receiving end plate are curved surfaces corresponding to each other. 7 . 7 . The electric field type wireless power transmission system according to claim 1 , wherein the receiving end plate is a sphere, and the transmitting end plate is a corresponding curved surface. 8 .

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