Multi-receiving-coil induced voltage imbalance parallel output circuit of wireless power transmission system

Abstract

The invention discloses a multi-receiving-coil induced voltage imbalance parallel output circuit of a wireless electric energy transmission system, which belongs to the technical field of electromagnetic induction type wireless electric energy transmission, and is characterized in that a plurality of receiving coils correspond to the same transmitting coil, and the structures and parameters of the receiving coils are the same; the mutual inductance between each receiving coil and the transmitting coil is different; each receiving coil adopts capacitor series compensation, a dotted terminal is respectively connected with one end of a compensation capacitor, the other end of the compensation capacitor is connected with one end of an alternating current side input end of a single-phase uncontrolled rectifier bridge, and the other end of the alternating current side input end of the single-phase uncontrolled rectifier bridge is connected with the other end of each receiving coil; the positive electrode of the direct current side of the single-phase uncontrolled rectifier bridge corresponding to each receiving coil is connected to the positive electrode of the load, and the negative electrode is connected to the negative electrode of the load; and the dotted terminals of the receiving coils are connected by using conductors. The parallel loop current generated when the induction voltages of the multiple receiving coils are unbalanced can be eliminated, the working condition application range of the system is expanded, circuit connection is simple, cost is low, and reliability is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic induction wireless power transmission, and particularly relates to a parallel output circuit for unbalanced induced voltages of multiple receiving coils in a wireless power transmission system. Background Art

[0002] When the transmission power of a wireless power transmission system is relatively large, multiple receiving coils are usually required and connected in parallel for output. As shown in Figure 1 、 Figure 2 , in the prior art, after each receiving coil is connected to a single-phase uncontrolled rectifier bridge for rectification and then connected in parallel (when the output voltage range after uncontrolled rectification of the output voltage of each receiving coil is the same as the load voltage range), or after each receiving coil is connected to a single-phase uncontrolled rectifier bridge and then connected to a DC-DC converter and then connected in parallel (when the output voltage range after uncontrolled rectification of the output voltage of each receiving coil is quite different from the load voltage range). When a wireless power transmission system includes multiple receiving coils and the distances between each receiving coil and the same transmitting coil are different, it is easy to cause different induced voltages in each receiving coil. When the induced voltages of multiple receiving coils are different, if each receiving coil is rectified by an uncontrolled rectifier bridge and then connected in parallel, it is easy to generate a large circulating current or even overcurrent in each receiving coil. Therefore, an equalization circuit needs to be added or equalization control needs to be performed when multiple receiving coils are connected in parallel for output.

[0003] Figure 1 is the parallel topology of the uncontrolled rectifier output of multiple receiving modules in the prior art wireless power transmission system, Figure 2 is the parallel topology of the output of multiple receiving modules in the prior art wireless power transmission system through a DC-DC converter. Among them, multiple receiving coils L s1 、L s2 , ……, L sn correspond to the same transmitting coil L p . The structures and parameters of each receiving coil are the same, and the mutual inductances between each receiving coil and the transmitting coil are different. To keep the current of the transmitting coil constant, a common implementation method is to connect the transmitting coil L p in series with a compensation capacitor C p , then connect it in parallel with a compensation capacitor C1, then connect it in series with a compensation inductor L1, and then connect the compensation inductor L1 in series to the transmitting side inverter INV, and the transmitting side inverter INV outputs a constant voltage. The same-named ends of each receiving coil L s1 、L s2 , ……, L sn are respectively connected to one end of compensation capacitors C s1 、C s2 , ……, C sn . The other ends of compensation capacitors C s1 、C s2 , ……, C snThe other ends are respectively connected to one end of the AC side input of a single-phase uncontrolled rectifier bridge, and the other ends of the AC side input of the single-phase uncontrolled rectifier bridge are respectively connected to each receiving coil L s1 、L s2 ,……,L sn 's other end. Ideally, the mutual inductance between each receiving coil and the transmitting coil is the same and constant, the current of the transmitting coil is constant, and the DC voltage after the induced voltage of each receiving coil is rectified by the single-phase uncontrolled rectifier bridge meets the power supply voltage requirement of the load R ld . When this is the case, the positive poles of the DC sides of the single-phase uncontrolled rectifier bridges corresponding to each receiving coil are all connected to the positive pole of the load R ld , and the negative poles are all connected to the negative pole of the load R ld . Since the induced voltages of each receiving coil are the same, there will be no large circulating current when the induced voltages of each receiving coil are directly connected in parallel after being rectified by the uncontrolled rectifier bridge. In practical applications, if the mutual inductance between each receiving coil and the transmitting coil is different, there will be a large circulating current when the induced voltages of each receiving coil are directly connected in parallel after being rectified by the uncontrolled rectifier bridge.

[0004] In addition, when the DC voltage value after the induced voltage of each receiving coil is rectified by the single-phase uncontrolled rectifier bridge cannot meet the power supply voltage requirement of the load R ld , it is usually necessary to connect a DC-DC converter in series after the induced voltage of each receiving coil is rectified by the uncontrolled rectifier bridge to adjust the output voltage of each receiving coil to meet the power supply voltage requirement of the load R ld . See Figure 2 for the adjustment of the output voltage by connecting a DC-DC converter in series with each receiving coil. The positive pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the positive pole of the input side of the DC-DC converter, and the negative pole is connected to the negative pole of the input side of the DC-DC converter. The positive poles of the output sides of each DC-DC converter are all connected to the positive pole of the load R ld , and the negative poles are all connected to the negative pole of the load R ld . Each DC-DC converter controls its own input voltage, and the control objective is to make the output voltages of each DC-DC converter reach the power supply voltage range required by the load R ld . Since the output voltages of the DC-DC converters of each receiving coil are the same, and it is considered that the output ends of each DC-DC converter to the load resistor R ldIf the connection line resistances are the same, the output powers of the DC-DC converters are basically the same. Ideally, the mutual inductances between the receiving coils and the transmitting coil are the same and constant, and this type of parallel connection method has good output power capabilities. In practical applications, when the mutual inductances between the receiving coils and the transmitting coil are different, as the load power increases, the output current of the receiving coil with a lower induced voltage will increase more. Considering the internal resistance of the receiving coil, the output voltage of this receiving coil will drop faster. Eventually, the output voltage of the receiving coil with too small an induced voltage may cause the corresponding DC-DC converter of this receiving coil to fail to start because its voltage is lower than the lower limit of the input voltage range of the DC-DC converter, or the output voltage of the receiving coil with too large an induced voltage may cause the corresponding DC-DC converter of this receiving coil to fail to start because its voltage is higher than the upper limit of the input voltage range of the DC-DC converter. Eventually, some receiving coils in the wireless power transmission system with multiple receiving coils cannot output power, thereby reducing the total output power of the system. Summary of the Invention

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A parallel output circuit for unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, comprising: multiple receiving coils corresponding to the same transmitting coil, with each receiving coil having the same structure and parameters; the mutual inductances between each receiving coil and the transmitting coil are different; each receiving coil uses capacitive series compensation, the same-named ends of each receiving coil are respectively connected to one end of a compensation capacitor, the other end of the compensation capacitor is connected to one end of the AC side input of an uncontrolled single-phase rectifier bridge, and the other end of the AC side input of the uncontrolled single-phase rectifier bridge is connected to the other end of each receiving coil;

[0007] The positive poles of the DC sides of the uncontrolled single-phase rectifier bridges corresponding to each receiving coil are all connected to the positive pole of the load, and the negative poles of the DC sides of the uncontrolled single-phase rectifier bridges corresponding to each receiving coil are all connected to the negative pole of the load;

[0008] Connect the same-named ends of each receiving coil with a conductor.

[0009] A parallel output circuit for unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, comprising:

[0010] Multiple receiving coils corresponding to the same transmitting coil, with each receiving coil having the same structure and parameters; the mutual inductances between each receiving coil and the transmitting coil are different; each receiving coil uses capacitive series compensation, the same-named ends of each receiving coil are respectively connected to one end of a compensation capacitor, the other end of the compensation capacitor is connected to one end of the AC side input of an uncontrolled single-phase rectifier bridge, and the other end of the AC side input of the uncontrolled single-phase rectifier bridge is connected to the other end of each receiving coil;

[0011] The positive pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the positive pole of the input side of the DC-DC converter, and the negative pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the negative pole of the input side of the DC-DC converter; the positive poles of the output sides of the DC-DC converters are all connected to the positive pole of the load, and the negative poles of the output sides of the DC-DC converters are all connected to the negative pole of the load;

[0012] Connect the like-named ends of each receiving coil with a conductor; at the same time, connect the positive poles of the input sides of the DC-DC converters with a conductor, and connect the negative poles of the input sides of the DC-DC converters with a conductor as well.

[0013] A parallel output circuit for unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, comprising:

[0014] Multiple receiving coils correspond to the same transmitting coil, and the structures and parameters of each receiving coil are the same; the mutual inductances between each receiving coil and the transmitting coil are different; each receiving coil adopts capacitive series compensation, one end of a compensation capacitor is respectively connected to the like-named end of each receiving coil, the other end of the compensation capacitor is connected to one end of the AC side input of the single-phase uncontrolled rectifier bridge, and the other end of the AC side input of the single-phase uncontrolled rectifier bridge is connected to the other end of each receiving coil;

[0015] The positive pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the positive pole of the input side of the DC-DC converter, and the negative pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the negative pole of the input side of the DC-DC converter; the positive poles of the output sides of the DC-DC converters are all connected to the positive pole of the load, and the negative poles of the output sides of the DC-DC converters are all connected to the negative pole of the load;

[0016] Connect the like-named ends of each receiving coil with a conductor; at the same time, connect one end of the AC side of each single-phase uncontrolled rectifier bridge connected to the compensation capacitor with a conductor, and connect one end of the AC side of each single-phase uncontrolled rectifier bridge connected to the receiving coil with a conductor as well.

[0017] The present invention has the following beneficial effects:

[0018] When the induced voltages of multiple receiving coils in the circuit structure of the present invention are different, they can still be safely and reliably paralleled, basically eliminating the circulating current between the receiving coils, improving the power transmission efficiency of the system, enabling the current of each receiving coil to reach the maximum value allowed by the coil cable, thereby increasing the maximum output power of the system. And when a DC-DC converter is connected to the subsequent stage of each receiving coil, it can enhance the ability of each DC-DC converter to maintain operation, expanding the applicable working conditions range of the system. The circuit structure of the present invention can increase the output voltage of the receiving coil with a lower induced voltage, thereby raising the input voltage of the DC-DC converter, and improving the problem that the DC-DC converter of the receiving coil stops working and cannot output power due to too low input voltage under working conditions such as too large a gap between some secondary coils and the primary coil resulting in too low induced voltage of these secondary coils. It can also reduce the output voltage of the receiving coil with a higher induced voltage, thereby lowering the input voltage of the DC-DC converter, and improving the problem that the DC-DC converter of the receiving coil stops working and cannot output power due to too high input voltage under working conditions such as too small a gap between some secondary coils and the primary coil resulting in too high induced voltage of these secondary coils. In addition, the circuit structure of the present invention has a simple connection relationship, does not require active control, has low cost and high reliability. Description of the Drawings

[0019] Figure 1 The uncontrolled rectifier bridge output parallel topology of multiple receiving coils in the wireless power transfer system of the prior art;

[0020] Figure 2 The output parallel topology of multiple receiving coils in the wireless power transfer system of the prior art through an uncontrolled rectifier bridge and a DC-DC converter;

[0021] Figure 3 The circuit structure diagram of the first embodiment of the present invention;

[0022] Figure 4(a) is the circuit structure diagram of the second embodiment of the present invention;

[0023] Figure 4(b) is the circuit structure diagram of the third embodiment of the present invention. Detailed Embodiments

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] The technical solution of the present invention will be described below by taking the high-power wireless power transmission system of rail transit vehicles as an example.

[0026] The power required for rail transit vehicles is relatively large, reaching the level of hundreds of kW to MW. It is difficult to meet the requirements with a single receiving coil. Multiple receiving coils are often used, and the outputs of multiple receiving coils are connected in parallel to supply power to the vehicle. The transmitting coil is usually arranged along the train track, and usually each section of the transmitting coil covers multiple receiving coils.

[0027] The first embodiment of the present invention is as Figure 3 shown. Figure 3 It is an uncontrolled rectifier output parallel circuit when the induced voltages of multiple receiving coils in the wireless power transmission system of the present invention are unbalanced. Among them, multiple receiving coils L s1 、L s2 , ……, L sn correspond to the same transmitting coil L p . The structures and parameters of each receiving coil are the same, and the mutual inductances between each receiving coil and the transmitting coil are different. To keep the current of the transmitting coil L p constant, the transmitting coil L p is connected in series with a compensation capacitor C p , and then connected in parallel with a compensation capacitor C1, and then connected in series with a compensation inductor L1. Then the compensation inductor L1 is connected in series to the inverter INV on the transmitting side. The same-named ends of each receiving coil L s1 、L s2 , ……, L sn are respectively connected to one end of the compensation capacitors C s1 、C s2 , ……, C sn . The other ends of the compensation capacitors C s1 、C s2 , ……, C sn are connected to one end of the AC side input of a single-phase uncontrolled rectifier bridge. The other end of the AC side input of the single-phase uncontrolled rectifier bridge is connected to the other ends of each receiving coil L s1 、L s2 , ……, L sn . The positive poles of the DC sides of the single-phase uncontrolled rectifier bridges corresponding to each receiving coil are all connected to the positive pole of the load R ld , and the negative poles are all connected to the negative pole of the load R ld . Confirm the same-named ends of each receiving coil, and use a conductor to connect the same-named end of the receiving coil L s1 to the same-named end of the receiving coil L s2 , and then use a conductor to connect the same-named end of the receiving coil L s2 to the same-named end of the receiving coil L s3 , and so on. Finally, the same-named ends of each receiving coil are connected together.

[0028] compared to Figure 1 The circuit structure, Figure 3 The beneficial effects of the circuit structure are as follows:

[0029] (1) Figure 3 By connecting the same-named terminals of each receiving coil together, the currents of the receiving coils with different induced voltages can be kept consistent, thus reducing circulating currents.

[0030] for Figure 1 Circuit: The induced voltage of each receiving coil is connected in series with the self-inductance L si and compensation capacitor C si (i=1,2…n) and then connected in parallel to both ends of the load. si and C si Resonance, the series impedance of the two is almost zero, so the parallel impedance of each receiving coil is very small. Therefore, when the induced voltages of the receiving coils are different, the parallel circulating current is large, and the current imbalance of each receiving coil is more serious.

[0031] for Figure 3 Circuit: One end of the induced voltage of each receiving coil passes through the self-inductance L si Then they are connected in parallel, and the other end of the induced voltage of each receiving coil is connected in parallel to the negative pole of the load through a rectifier diode. The parallel impedance of each receiving coil is mainly the self-inductance L si , since the receiving coil of the wireless power transmission system usually has more turns and sometimes also adds a magnetic core, so L si The parallel impedance of each receiving coil is large, and since the operating frequency of the wireless power transmission system is high, it can be seen that when the induced voltages of the receiving coils are different, the parallel circulating current is very small, and the currents of the receiving coils are basically the same.

[0032] visible, Figure 3 The circuit is relatively Figure 1 The circuit can improve the current balancing capability of the receiving coil. Similarly, the circuits of FIG4 (a) and FIG4 (b) of the present invention are better than those of the prior art. Figure 2 The circuit can also improve the current balancing capability of the receiving coil.

[0033] (2) Figure 3 The circuit can reduce the total internal resistance loss of each receiving coil by connecting the same-named ends of each receiving coil together, thereby improving the power transmission efficiency of the system.

[0034] If the induced voltages of the receiving coils are different, Figure 1 The current imbalance of each receiving coil in the circuit is relatively large. Figure 3The degree of imbalance of the currents in each receiving coil is relatively small. Assuming that the internal resistances of each receiving coil are basically the same, according to circuit theory, when providing the same total output current to the load, when the degree of imbalance of the currents in each receiving coil is large, the total loss of each receiving coil is large. When the currents in each receiving coil are relatively balanced, the total loss of each receiving coil is small. Therefore Figure 1 the total sum of the internal resistance losses of the receiving coils in the circuit is large, and the system efficiency is low; Figure 3 the total sum of the internal resistance losses of the receiving coils in the circuit is small, and the system efficiency is high.

[0035] It can be seen that the Figure 3 circuit of the present invention Figure 1 compared with the circuit of the prior art Figure 2 can improve the system efficiency. By the same token, the circuits of FIGS. 4(a) and 4(b) of the present invention

[0036] (3) Figure 3 The circuit of the present invention can improve the power output capacity of the system by connecting the like-named ends of each receiving coil together. When the induced voltages of each receiving coil are different, Figure 1 the currents in the receiving coils of the circuit are unbalanced. As the load power increases, the output current of the receiving coil with a larger current will reach the maximum current value allowed by the receiving coil cable first. At this time, the system output power cannot continue to increase, but the output current of the receiving coil with a smaller current has not reached the maximum current value allowed by the receiving coil cable. Therefore, the power output capacity of each receiving coil is not fully utilized. And Figure 3 the currents in the receiving coils of the circuit are basically the same. As the load power increases, the output currents of each receiving coil will reach the maximum current value allowed by the receiving coil cable synchronously. Therefore, the total sum of the output currents of each receiving coil reaches the maximum, and the power output capacity is maximized.

[0037] It can be seen that compared with the Figure 1 circuit of the prior art, the Figure 3 circuit of the present invention Figure 2 can improve the power output capacity of the system. The circuits of FIGS. 4(a) and 4(b) of the present invention

[0038] The second and third embodiments of the present invention are shown in FIGS. 4(a) and 4(b). FIG. 4(a) is the first circuit structure diagram of the parallel output of the multi-receiving coil of the wireless power transmission system of the present invention through an uncontrolled rectifier bridge and a DC-DC converter. When the induced voltages of the receiving coils are unbalanced, a parallel output equalization circuit of the receiving coils is formed by connecting conductors in parallel on the DC side of the uncontrolled rectifier bridge; FIG. 4(b) is the second circuit structure diagram of the parallel output of the multi-receiving coil of the wireless power transmission system of the present invention through an uncontrolled rectifier bridge and a DC-DC converter. When the induced voltages of the receiving coils are unbalanced, a parallel output equalization circuit of the receiving coils is formed by connecting conductors in parallel on the AC side of the uncontrolled rectifier bridge. Among them, multiple receiving coils L s1 、L s2 ,……,L sn correspond to the same transmitting coil Lp. The structures and parameters of the receiving coils are the same, and the mutual inductances between the receiving coils and the transmitting coil are different. To keep the current of the transmitting coil constant, the transmitting coil L p is connected in series with a compensation capacitor C p , and then connected in parallel with the compensation capacitor C1. After that, the network formed by the above L p 、C p 、C1 is connected in series with a compensation inductor L1, and then connected to the transmitting side inverter INV. The same-named ends of the receiving coils L s1 、L s2 ,……,L sn are respectively connected in series with the compensation capacitors C s1 、C s2 ,……,C sn at one end. The other ends of the compensation capacitors C s1 、C s2 ,……,C sn are connected to one end of the AC side input of a single-phase uncontrolled rectifier bridge. The other end of the AC side input of the single-phase uncontrolled rectifier bridge is respectively connected to the other ends of the receiving coils L s1 、L s2 ,……,L sn . The positive poles of the DC sides of the single-phase uncontrolled rectifier bridges of the receiving coils are connected to the positive pole of the input side of the DC-DC converter, and the negative poles of the DC sides of the single-phase uncontrolled rectifier bridges of the receiving coils are connected to the negative pole of the input side of the DC-DC converter. The positive poles of the output sides of the DC-DC converters are all connected to the positive pole of the load R ld , and the negative poles are all connected to the negative pole of the load R ld . Each DC-DC converter controls its own input voltage, and the control target is to make the output voltages of all DC-DC converters reach the power supply voltage range required by the load R ld . A conductor is used to connect the same-named end of the receiving coil L s1 to the same-named end of the receiving coil L s2 , and then another conductor is used to connect the receiving coil Ls2 The homonymous terminals are connected to the receiving coil L s3 The homonymous terminals, and so on. Finally, the homonymous terminals of each receiving coil are connected together. At the same time, the positive poles of the input sides of each DC-DC converter are connected together using a conductor, and the negative poles of the input sides of each DC-DC converter are connected together using a conductor, as shown in Fig. 4(a); or, one ends of the compensation capacitors connected to the AC sides of each single-phase uncontrolled rectifier bridge are connected together using a conductor, and one ends of the receiving coils connected to the AC sides of each single-phase uncontrolled rectifier bridge are also connected together using a conductor, as shown in Fig. 4(b).

[0039] Compared with the Figure 2 circuit structure of the prior art, the beneficial effects of the circuit structure shown in Fig. 4(a) or Fig. 4(b) of the present invention are as follows:

[0040] The circuit shown in Fig. 4(a) or Fig. 4(b) of the present invention can make the currents of receiving coils with different induced voltages consistent, reduce circulating current, improve the power transmission efficiency of the system, and increase the output power of the system. The basic principle is as described above, which is similar to the Figure 3 circuit of the present invention Figure 1 compared with the beneficial effects of the Figure 2 circuit of the prior art. Fig. 4(a) or Fig. 4(b) can also enhance the ability of each DC-DC converter to keep working, thereby expanding the applicable working condition range of the system. The reasons are as follows:

[0041] Figure 2 In the ld circuit, usually the output voltages of each DC-DC converter are controlled to reach the power supply voltage value required by the load R ldIf the connection line resistances are the same, the output powers of the DC-DC converters are basically the same. Ignoring the differences in the losses of the DC-DC converters of each receiving coil and the differences in the internal resistance losses of each receiving coil, the received powers of all receiving coils are the same. Since the powers of each receiving coil are the same, the coil current of the receiving coil with a smaller induced voltage is larger, and the coil current of the receiving coil with a larger induced voltage is smaller. As the load power increases, the received powers of each receiving coil remain the same and increase synchronously. Then, the increase amplitude of the current of the receiving coil with a smaller induced voltage is larger, and the increase amplitude of the current of the receiving coil with a larger induced voltage is smaller. Assuming that the internal resistances of each receiving coil are the same, as the load power increases, the voltage drop across the coil internal resistance of the receiving coil with a smaller induced voltage increases more, and the voltage drop across the coil internal resistance of the receiving coil with a larger induced voltage increases less. The input voltage of each DC-DC converter (i.e., the output voltage of each receiving coil) is equal to the induced voltage of each receiving coil (assuming this voltage remains unchanged) minus the voltage drop across the internal resistance of each receiving coil. Therefore, as the load power increases, the input voltage of the DC-DC converter of the receiving coil with a smaller induced voltage drops faster, and the input voltage of the DC-DC converter of the receiving coil with a larger induced voltage drops slower. Eventually, the input voltage of the DC-DC converter of the receiving coil with a smaller induced voltage stops working because it is first less than the minimum value of the input voltage of the DC-DC converter, and this receiving coil stops outputting power.

[0042] The circuit in Fig. 4(a) or Fig. 4(b) can achieve current sharing among each receiving coil. As the load power increases, the increase amplitude of the current of each receiving coil in the circuit of Fig. 4 is the same, while Figure 2 in the circuit, the increase amplitude of the coil current of the receiving coil with a smaller induced voltage is larger, and the increase amplitude of the coil current of the receiving coil with a larger induced voltage is smaller. Therefore, as the load power increases, the dropping speed of the input voltage of the DC-DC converter of the receiving coil with a smaller induced voltage is slower in the circuit of Fig. 4(a) or Fig. 4(b) than that in the Figure 2 circuit. The time when the input voltage of the DC-DC converter of the receiving coil with a smaller induced voltage stops working because it is less than the minimum value of the input voltage of the DC-DC converter is delayed. Therefore, the circuit of Fig. 4 enhances the ability of each DC-DC converter to keep working compared with the Figure 2 circuit of the prior art, thereby expanding the applicable working condition range of the system.

[0043] The above are only the embodiments of the present invention, and thus do not limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related system fields, shall be equally included in the protection scope of the present invention. The content not detailedly described in the specification of the present invention belongs to the prior art well-known to those skilled in the art.

Claims

1. A parallel output circuit for the unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, characterized in that, Including: A plurality of receiving coils correspond to the same transmitting coil, and the structures and parameters of the receiving coils are the same; the mutual inductances between the receiving coils and the transmitting coil are different; the mutual inductances between the receiving coils and the transmitting coil are different; each receiving coil adopts capacitive series compensation, the same-named ends of each receiving coil are respectively connected to one end of a compensation capacitor, the other end of the compensation capacitor is connected to one end of the AC side input terminal of a single-phase uncontrolled rectifier bridge, and the other end of the AC side input terminal of the single-phase uncontrolled rectifier bridge is connected to the other end of each receiving coil; The positive poles of the DC sides of the single-phase uncontrolled rectifier bridges corresponding to the receiving coils are all connected to the positive pole of the load, and the negative poles of the DC sides of the single-phase uncontrolled rectifier bridges corresponding to the receiving coils are all connected to the negative pole of the load; Connect the same-named ends of each receiving coil with a conductor.

2. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transfer system according to claim 1, wherein After confirming the same-named ends of each receiving coil, use a conductor to connect the same-named end of the first receiving coil to the same-named end of the second receiving coil, and then use a conductor to connect the same-named end of the second receiving coil to the same-named end of the third receiving coil, and so on, until the same-named ends of all the receiving coils are connected together.

3. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to claim 1, wherein To keep the current of the transmitting coil constant, a compensating capacitor C is connected in series with the transmitting coil p and then connected in parallel with a compensating capacitor C1, and then connected in series with a compensating inductor L1, and then the compensating inductor L1 is connected in series to the transmitting side inverter.

4. A parallel output circuit for the unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, characterized in that, Including: A plurality of receiving coils correspond to the same transmitting coil, and the structures and parameters of the receiving coils are the same; The mutual inductances between the receiving coils and the transmitting coil are different; Each receiving coil adopts capacitive series compensation, the same-named ends of each receiving coil are respectively connected to one end of a compensation capacitor, the other end of the compensation capacitor is connected to one end of the AC side input terminal of a single-phase uncontrolled rectifier bridge, and the other end of the AC side input terminal of the single-phase uncontrolled rectifier bridge is connected to the other end of each receiving coil; The positive poles of the DC sides of the single-phase uncontrolled rectifier bridges of the receiving coils are connected to the positive pole of the input side of a DC-DC converter, and the negative poles of the DC sides of the single-phase uncontrolled rectifier bridges of the receiving coils are connected to the negative pole of the input side of the DC-DC converter; the positive poles of the output sides of the DC-DC converters are all connected to the positive pole of the load, and the negative poles of the output sides of the DC-DC converters are all connected to the negative pole of the load; Connect the same-named ends of each receiving coil with a conductor; at the same time, connect the positive poles of the input sides of the DC-DC converters with a conductor, and connect the negative poles of the input sides of the DC-DC converters with a conductor.

5. The parallel output circuit for unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to claim 4, wherein After confirming the same-named ends of each receiving coil, use a conductor to connect the same-named end of the first receiving coil to the same-named end of the second receiving coil, and then use a conductor to connect the same-named end of the second receiving coil to the same-named end of the third receiving coil, and so on, until the same-named ends of all the receiving coils are connected together; use the same method to connect the positive poles of the input sides of the DC-DC converters together, and connect the negative poles of the input sides of the DC-DC converters with a conductor.

6. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to claim 4, wherein To keep the current of the transmitting coil constant, a compensating capacitor C is connected in series with the transmitting coil. p After that, it is connected in parallel with the compensating capacitor C1, then connected in series with the compensating inductor L1, and the compensating inductor L1 is connected in series to the transmitting side inverter.

7. A parallel output circuit for the unbalanced induced voltages of multiple receiving coils in a wireless power transmission system, characterized in that, Including: A plurality of receiving coils correspond to the same transmitting coil, and the structures and parameters of the receiving coils are the same; The mutual inductances between the receiving coils and the transmitting coil are different; Each receiving coil adopts capacitive series compensation, the same-named ends of each receiving coil are respectively connected to one end of a compensation capacitor, the other end of the compensation capacitor is connected to one end of the AC side input terminal of a single-phase uncontrolled rectifier bridge, and the other end of the AC side input terminal of the single-phase uncontrolled rectifier bridge is connected to the other end of each receiving coil; The positive pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the positive pole of the input side of the DC-DC converter, and the negative pole of the DC side of the single-phase uncontrolled rectifier bridge of each receiving coil is connected to the negative pole of the input side of the DC-DC converter; the positive poles of the output sides of the DC-DC converters are all connected to the positive pole of the load, and the negative poles of the output sides of the DC-DC converters are all connected to the negative pole of the load; Connect the like-named ends of each receiving coil with a conductor; at the same time, connect one end of the compensation capacitor connected to the AC side of each single-phase uncontrolled rectifier bridge with a conductor, and also connect one end of the AC side of each single-phase uncontrolled rectifier bridge connected to the receiving coil with a conductor.

8. The parallel output circuit for uneven induced voltages of multiple receiving coils in the wireless power transmission system according to claim 7, characterized in that After confirming the like-named ends of each receiving coil, connect the like-named end of the first receiving coil to the like-named end of the second receiving coil with a conductor, and then connect the like-named end of the second receiving coil to the like-named end of the third receiving coil with a conductor, and so on, finally connecting the like-named ends of all the receiving coils together; use the same method to connect one end of the compensation capacitor connected to the AC side of each single-phase uncontrolled rectifier bridge together, and also connect one end of the AC side of each single-phase uncontrolled rectifier bridge connected to the receiving coil with a conductor.

9. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to claim 7, wherein To keep the current of the transmitting coil constant, a compensating capacitor C is connected in series with the transmitting coil. p After that, it is connected in parallel with the compensating capacitor C1, then connected in series with the compensating inductor L1, and the compensating inductor L1 is connected in series to the transmitting side inverter.

10. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to any one of claims 4 to 9, characterized in that Adjust to make the output voltages of the DC-DC converters of each receiving coil consistent.

11. The parallel output circuit for the unbalanced induced voltages of multiple receiving coils in the wireless power transmission system according to any one of claims 1 to 9, characterized in that, Parallel the outputs of multiple receiving coils to supply power to the vehicle; the transmitting coils are arranged along the train track, and each section of the transmitting coil covers several receiving coils.

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