CN110365123A - A compensation circuit for a two-phase wireless charging system - Google Patents

Abstract

The present invention provides a compensation circuit for a two-phase wireless charging system, including a first-phase circuit and a second-phase circuit with identical structures, characterized in that the end of the inductor L1 connected to the capacitor C1 and the end of the inductor L2 connected to the capacitor C2 One end is directly connected; one end of the first inductance Lr1 of the receiving coil of the wireless charging system connected to the capacitor Cr1 is directly connected to one end of the second inductance Lr2 of the receiving coil of the wireless charging system connected to the capacitor Cr2. The present invention can make the current distribution of the two-phase circuit more uniform by simply connecting the components of the primary and secondary sides without increasing the complexity of the system.

Description

A compensation circuit for a two-phase wireless charging system

technical field

The invention relates to a compensation circuit of a two-phase wireless charging system.

Background technique

Wireless charging will become the mainstream, and now the IPT solution using the LCC-C compensation circuit makes the wireless charging technology gradually mature. Wireless charging is not only popular in low-power adapters, but will gradually be implemented in electric vehicles. However, high-power output requires components with higher voltage and current specifications, which not only increases the difficulty of the device manufacturing process, but also greatly increases the production cost. The existing scheme uses the same circuit of multiple phases in series and parallel on the primary side and the secondary side, and distributes the power evenly among the phases. The first phase circuit includes a resonant circuit composed of an inductance L1 and a capacitor C1, a resonant circuit composed of a capacitor C1, a capacitor Ct1 and the transmitting coil of the wireless charging system-inductance Lt1, and a receiving coil of the wireless charging system-inductance Lr1 and a resonant circuit composed of capacitor Cr1, a rectifier circuit composed of diodes D1, D2, D3, and D4; the second-phase circuit includes a resonant circuit composed of inductance L2 and capacitor C2, a capacitor C2, capacitor Ct2 and the transmission of the wireless charging system The resonant circuit composed of the second coil inductance Lt2, the resonant circuit composed of the second inductance Lr2 of the receiving coil of the wireless charging system and the capacitor Cr2, and the rectifier circuit composed of diodes D5, D6, D7, and D8. The first-phase circuit and the second-phase circuit convert the input alternating current into direct current and load it on the load R1. Although the circuit structure of the first-phase circuit and the second-phase circuit are the same, and the selected component models are also the same, the two components of the same model still have parameter deviations due to problems in the manufacturing process, which makes the first-phase circuit and the The current distribution of the second phase circuit is not uniform, that is, the power distribution of each phase is not uniform.

SUMMARY OF THE INVENTION

The purpose of the present invention is to make the current distribution of the two-phase circuit more uniform.

In order to achieve the above purpose, the technical solution of the present invention is to provide a compensation circuit for a two-phase wireless charging system, including a first-phase circuit and a second-phase circuit with identical structures: the first-phase circuit includes an input terminal that is connected to an AC input Resonant circuit 1 whose output end is connected to the input end of resonant circuit 2 is composed of inductor L1 and capacitor C1. One end of inductor L1 is connected to the AC input, and the other end is connected to capacitor C1. The connected capacitors C1, The capacitor Cr1 and the transmitting coil-inductor Lt1 of the wireless charging system form the second resonant circuit. The receiving coil of the wireless charging system, the inductor Lr1 and the capacitor Cr1 form the resonant circuit 3. The resonant circuit 3 is connected to the input of the rectifier circuit 1, and the output of the rectifier circuit 1 Connect the load R1; the second phase circuit includes a resonant circuit 5 whose input end is connected to the AC input and the output end is connected to the input end of the resonant circuit 4. The resonant circuit 5 is composed of an inductor L2 and a capacitor C2, wherein one end of the inductor L2 is connected to the AC The input is connected, and the other end is connected to the capacitor C2. The connected capacitor C2, capacitor Cr2 and the second inductance Lt2 of the transmitting coil of the wireless charging system form a resonant circuit 4. The second inductance Lr2 of the receiving coil of the wireless charging system and the capacitor Cr2 form a resonant circuit. Six, resonance The circuit 6 is connected to the input of the rectifier circuit 2, and the output of the rectifier circuit 2 is connected to the load R1. It is characterized in that the end of the inductor L1 connected to the capacitor C1 and the end of the inductor L2 connected to the capacitor C2 are directly connected; One end of the inductance Lr1 connected to the capacitor Cr1 is directly connected to one end of the inductance Lr2 connected to the capacitor Cr2 of the receiving coil of the wireless charging system.

Preferably, the first rectifier circuit is composed of diodes D1, D2, D3, and D4; the second rectifier circuit is composed of diodes D5, D6, D7, and D8.

The present invention can make the current distribution of the two-phase circuit more uniform by simply connecting the components of the primary and secondary sides without increasing the complexity of the system.

Description of drawings

1 is a schematic diagram of an existing circuit;

2 is a schematic diagram of a circuit provided by the present invention;

3(a) to 3(h) are comparison diagrams of simulation results of the compensation circuit in the two-phase wireless charging system of the present invention and the existing circuit.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

As shown in FIG. 2 , a compensation circuit for a two-phase wireless charging system provided by the present invention includes a first-phase circuit and a second-phase circuit with identical structures.

The first phase circuit includes a resonant circuit 1 whose input end is connected to the AC input and the output end is connected to the input end of the second resonant circuit. The first resonant circuit is composed of an inductor L1 and a capacitor C1, wherein one end of the inductor L1 is connected to the AC input, and the other is connected to the AC input. One end is connected to the capacitor C1, the second resonant circuit includes the connected capacitor C1, the capacitor Cr1 and the transmitting coil of the wireless charging system-inductor Lt1, the receiving coil of the wireless charging system-inductor Lr1 and the capacitor Cr1 form the resonant circuit 3, the resonant circuit 3 and the rectifier The input of circuit one is connected, and the output of rectifier circuit one is connected to the load R1. Rectifier circuit one consists of diodes D1, D2, D3, D4

The second phase circuit includes a resonant circuit 5 whose input end is connected to the AC input and the output end is connected to the input end of the resonant circuit 4. The resonant circuit 5 is composed of an inductor L2 and a capacitor C2, wherein one end of the inductor L2 is connected to the AC input, and the other end is connected to the AC input. One end is connected to the capacitor C2, and the resonant circuit four includes the connected capacitor C2, the capacitor Cr2 and the second inductance Lt2 of the transmitting coil of the wireless charging system. The inputs of the second circuit are connected, and the output of the second rectifier circuit is connected to the load R1. The second rectifier circuit is composed of diodes D5, D6, D7 and D8.

In the present invention, one end of the inductor L1 connected to the capacitor C1 and one end of the inductor L2 connected to the capacitor C2 are directly connected; The end connected to the capacitor Cr2 is directly connected.

In the present invention, in the receiving end circuit, the end of the inductor L1 connected to the capacitor C1 and the end of the inductor L2 connected to the capacitor C2 are directly connected, so that the originally unequal currents can reach a balanced state, that is, the current will change from the current to the current. The phase with the larger value flows to the phase with the smaller current value, so that the input current values of the first-phase circuit and the second-phase circuit reach the same state. The transmitter and receiver are independent to a certain extent. Even if the transmitter circuit achieves current sharing, the current of the receiver circuit has a large deviation. Therefore, the end of the receiving coil of the wireless charging system connected to the inductor Lr1 and the capacitor Cr1 is directly connected to the end of the receiving coil of the wireless charging system. The inductor Lr2 is connected to the capacitor Cr2. The same principle makes the receiving coil of the wireless charging system. It is equal to the current of the second inductance Lr2 of the receiving coil of the wireless charging system, so the effective value of the current rectified by the rectifier circuit 1 and the rectifier circuit 2 is the same, which makes the input power and output of the first phase circuit and the second phase circuit. The power is equal, and the original design goal is reached

In this embodiment, the specific values of the components used in the first phase circuit and the second phase circuit are shown in the following table:

Based on the parameters in the above table, the present invention is simulated as shown in Fig. 3(a) to Fig. 3(h), as shown in Fig. 3(a), Fig. 3(c), Fig. 3(e) and Fig. 3(g) , in the traditional scheme, the currents measured in each phase are not equal, and the effect of uniform current distribution in each phase is not achieved. In the scheme of the present invention as shown in Fig. 3(b), Fig. 3(d), Fig. 3(f) and Fig. 3(h), the RMS values of the currents measured in each phase are equal, and the The effect of uniform distribution of current, so as to achieve uniform distribution of power.

Claims (2)

1. A compensation circuit for a two-phase wireless charging system, comprising a first-phase circuit and a second-phase circuit with exactly the same structure: the first-phase circuit includes an input terminal connected to an AC input and an output terminal connected to the input terminal of the second resonant circuit. The first resonant circuit is composed of an inductor L1 and a capacitor C1. One end of the inductor L1 is connected to the AC input, and the other end is connected to the capacitor C1. The connected capacitor C1, capacitor Cr1 and the wireless charging system transmit coil-inductance Lt1 forms resonant circuit 2, the receiving coil of the wireless charging system 1, inductor Lr1 and capacitor Cr1 form resonant circuit 3, resonant circuit 3 is connected to the input of rectifier circuit 1, and the output of rectifier circuit 1 is connected to load R1; the second phase circuit includes an input terminal The resonant circuit five is connected to the AC input and the output terminal is connected to the input terminal of the resonant circuit four. The resonant circuit five is composed of an inductor L2 and a capacitor C2. One end of the inductor L2 is connected to the AC input, and the other end is connected to the capacitor C2. The capacitor C2, capacitor Cr2 and the second inductance Lt2 of the transmitting coil of the wireless charging system form a resonant circuit 4. The second inductance Lr2 of the receiving coil of the wireless charging system and the capacitor Cr2 form a resonant circuit 6. The resonant circuit 6 is connected to the input of the rectifier circuit 2, rectifying The output of circuit 2 is connected to the load R1, which is characterized in that the end of the inductor L1 connected to the capacitor C1 and the end of the inductor L2 connected to the capacitor C2 are directly connected; the receiving coil of the wireless charging system—the end of the inductor Lr1 connected to the capacitor Cr1 is connected to the wireless charging system. The second end of the receiving coil inductance Lr2 of the system is directly connected to one end of the capacitor Cr2. 2 . The compensation circuit of a two-phase wireless charging system according to claim 1 , wherein the first rectifier circuit is composed of diodes D1, D2, D3, and D4; the second rectifier circuit is composed of diodes D5 and D6. 3 . , D7, D8 composition.