Battery pack transformation charging circuit

Abstract

The invention relates to the technical field of battery pack charging and discharging circuits, in particular to a battery pack voltage transformation charging circuit which is used for being connected between a battery pack and a bus and comprises a first transformer, and the output end of the first transformer is connected with a first main loop H bridge connected with the battery pack. The positive electrode access end of the first transformer is connected with the direct current positive electrode of a third main loop H bridge connected with a bus, the output end of the second transformer is connected with a second main loop H bridge connected with a battery pack, and the input end of the second transformer is used for being connected with the direct current negative electrode of the third main loop H bridge connected with the bus; according to the invention, the circuit for charging and discharging the battery pack can adapt to the bus voltage in a single-phase inverter environment and the bus voltage in a three-phase inverter environment on the premise that the circuit structure does not need to be adjusted, and the adaptability of the circuit for charging and discharging the battery pack to different types of buses is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack charging and discharging circuits, and in particular to a battery pack voltage conversion charging circuit. Background Art

[0002] With the rapid development of battery charging and discharging technology, more and more electrical devices use battery packs as power sources. Battery packs can supply power to the busbar of electrical devices or obtain power from the busbar to supply power or charge the electrical devices. At present, the busbars of major electrical devices include the busbars of single-phase inverters and the busbars of three-phase inverters. Furthermore, the busbars of single-phase inverters can provide a relatively low voltage to the battery pack, such as a relatively low voltage of 300V-600V, and the busbars of three-phase inverters can provide a relatively high voltage to the battery pack, such as a high voltage of 600V-1000V.

[0003] However, the current charging and discharging circuits of the battery packs of electrical equipment mostly only support connection to a single single-phase or three-phase inverter bus. If it is necessary to support charging or discharging to the bus of a single-phase inverter and the bus of a three-phase inverter, two different charging and discharging circuits need to be set up, resulting in low adaptability of the battery pack charging and discharging circuits to different types of busbars. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a battery pack voltage conversion charging circuit.

[0005] The present invention provides a battery pack voltage conversion charging circuit, which is used to be connected between a battery pack and a bus bar. The battery pack voltage conversion charging circuit includes:

[0006] A first transformer, wherein the output end of the first transformer is connected to the first main circuit H bridge connected to the battery pack, and the positive electrode access end of the first transformer is connected to the DC positive electrode of the third main circuit H bridge connected to the busbar;

[0007] a second transformer, wherein the output end of the second transformer is used to be connected to the second main circuit H bridge connected to the battery pack, and the input end of the second transformer is used to be connected to the negative pole of the direct current of the third main circuit H bridge connected to the busbar;

[0008] A circuit conversion device, the circuit conversion device comprising a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4, wherein a first end of the first switch S1 is used to be connected to a DC positive electrode of the third main loop H bridge, and a second end of the first switch S1 is connected to an input end of the second transformer T2;

[0009] The first end of the second switch S2 is connected to the input end of the first transformer, the output end of the first transformer is connected to the negative pole of the DC power of the first main loop H bridge, and the second end of the second switch S2 is used to connect to the negative pole of the DC power of the third main loop H bridge;

[0010] A first end of the third switch S3 is connected to the input end of the first transformer, an output end of the first transformer is connected to the positive pole of the DC power of the first main circuit H bridge, a second end of the third switch is connected to the input end of the second transformer, and an output end of the second transformer is connected to the positive pole of the DC power of the second main circuit H bridge;

[0011] The first end of the fourth switch S4 is connected to the input end of the second transformer, the output end of the second transformer T2 is connected to the negative pole of the DC power of the second main loop H bridge, and the second end of the fourth switch S4 is connected to the input end of the first transformer;

[0012] Further, the circuit conversion device further includes a first inductor L1 and a second inductor L2, wherein a first end of the first inductor L1 is connected to a DC positive electrode of the third main loop H bridge, a second end of the first inductor L1 is connected to an input end of the second transformer T2, a first end of the second inductor L2 is connected to a DC positive electrode of the third main loop H bridge, and a second end of the second inductor L2 is connected to an input end of the first transformer T1;

[0013] Further, the third main loop H bridge is respectively composed of a switch tube Q1, a switch tube Q2, a switch tube Q3, a switch tube Q4 and a third capacitor C3, the switch tube Q1 and the switch tube Q2 are located on one side of the main loop H bridge of the bus, the switch tube Q3 and the switch tube Q4 are located on the other side of the main loop H bridge of the bus, the switch tube Q1 and the switch tube Q2 are connected in series, the switch tube Q3 and the switch tube Q4 are connected in series, the switch tube Q1 and the switch tube Q3 are connected to the positive electrode of direct current, and the switch tube Q2 and the switch tube Q4 are connected to the negative electrode of direct current;

[0014] The first end of the first switch S1 is connected to the output of the connection midpoint between the switch tube Q1 and the switch tube Q2, and the second end of the second switch S2 is connected to the output of the connection midpoint between the switch tube Q3 and the switch tube Q4;

[0015] Further, the first main loop H bridge is composed of a switch tube Q5, a switch tube Q6, a switch tube Q7, a switch tube Q8 and a first capacitor C1, the switch tube Q5 and the switch tube Q6 are located on one side of the first main loop H bridge, the switch tube Q7 and the switch tube Q8 are located on the other side of the first main loop H bridge, the switch tube Q5 and the switch tube Q6 are connected in series, the switch tube Q7 and the switch tube Q8 are connected in series, the switch tube Q5 and the switch tube Q7 are connected to the positive electrode of direct current, and the switch tube Q6 and the switch tube Q8 are connected to the negative electrode of direct current;

[0016] The first end of the third switch S3 is connected to the input end of the first transformer, and the output end of the first transformer is respectively connected to the connection midpoint output of the switch tube Q5 and the switch tube Q6 and the connection midpoint output of the switch tube Q7 and the switch tube Q8;

[0017] Further, the second main circuit H bridge is composed of a switch tube Q9, a switch tube Q10, a switch tube Q11, a switch tube Q12 and a second capacitor C2, the switch tube Q9 and the switch tube Q10 are located on one side of the second main circuit H bridge of the battery pack, the switch tube Q11 and the switch tube Q12 are located on the other side of the first main circuit H bridge, the switch tube Q9 and the switch tube Q10 are connected in series, the switch tube Q11 and the switch tube Q12 are connected in series, the switch tube Q9 and the switch tube Q11 are connected to the positive electrode of direct current, and the switch tube Q10 and the switch tube Q12 are connected to the negative electrode of direct current;

[0018] The second end of the second switch S2 is connected to the input end of the second transformer, and the output end of the second transformer is respectively connected to the connection midpoint output of the switch tube Q9 and the switch tube Q10 and the connection midpoint output of the switch tube Q11 and the switch tube Q12;

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The battery pack transformer charging circuit of the present application adjusts the parallel and series relationship between the two transformers included in the circuit by adjusting the on and off relationship of the first switch, the second switch, the third switch and the fourth switch included in the circuit conversion device. When the first transformer is connected in parallel with the second transformer, the circuit can adapt to the lower voltage of the single-phase inverter bus. When the first transformer is connected in series with the second transformer, the circuit can adapt to the higher voltage of the three-phase inverter bus. The circuit for charging and discharging the battery pack can adapt to the bus voltage in a single-phase inverter environment and the bus voltage in a three-phase inverter environment without adjusting the circuit structure, thereby improving the adaptability of the circuit for charging and discharging the battery pack to different types of buses. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following drawings are only used to illustrate and explain the present invention, and are not used to limit the scope of the present invention, wherein:

[0022] Figure 1 : One of the structural schematic diagrams of a battery pack voltage conversion charging circuit provided by an embodiment of the present invention;

[0023] Figure 2 : A second structural diagram of a battery pack voltage conversion charging circuit provided by an embodiment of the present invention;

[0024] Figure 3 : A third structural schematic diagram of a battery pack voltage transformer charging circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution, design method and advantages of the present invention clearer, the present invention is further described in detail by specific embodiments in conjunction with the accompanying drawings. 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.

[0026] like Figure 1 As shown, the present invention provides a battery pack voltage transformation charging circuit for connecting between a battery pack and a bus; the battery pack voltage transformation charging circuit includes a first transformer T1, a second transformer T2 and a circuit conversion device 110.

[0027] A first transformer T1, wherein the output end of the first transformer T1 is connected to the first main circuit H bridge connected to the battery pack, and the positive electrode access end of the first transformer T1 is connected to the DC positive electrode of the third main circuit H bridge connected to the busbar;

[0028] A second transformer T2, wherein the output end of the second transformer T2 is used to be connected to the second main circuit H bridge connected to the battery pack, and the input end of the second transformer T2 is used to be connected to the negative pole of the direct current of the third main circuit H bridge connected to the busbar;

[0029] A circuit conversion device 110, the circuit conversion device 110 comprises a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4, wherein a first end of the first switch S1 is used to be connected to a DC positive electrode of the third main loop H bridge, and a second end of the first switch S1 is connected to an input end of the second transformer T2;

[0030] The first end of the second switch S2 is connected to the input end of the first transformer T1, the output end of the first transformer T1 is connected to the negative pole of the DC power of the first main loop H bridge, and the second end of the second switch S2 is used to connect to the negative pole of the DC power of the third main loop H bridge;

[0031] A first end of the third switch S3 is connected to an input end of the first transformer T1, an output end of the first transformer T1 is connected to a DC positive electrode of the first main circuit H bridge, a second end of the third switch is connected to an input end of the second transformer T2, and an output end of the second transformer T2 is connected to a DC positive electrode of the second main circuit H bridge;

[0032] The first end of the fourth switch S4 is connected to the input end of the second transformer T2, the output end of the second transformer T2 is connected to the negative pole of the DC power of the second main loop H bridge, and the second end of the fourth switch S4 is connected to the input end of the first transformer T1;

[0033] In actual application, Figure 2 As shown, when the bus is the bus of a single-phase inverter, its bus voltage is a relatively low voltage, such as 360V-580V. At this time, the first switch S1, the second switch S2, and the third switch S3 are turned on, and the fourth switch S4 is turned off, so that the first transformer T1 and the second transformer T2 are in a parallel structure, the voltage value provided by the circuit to the battery pack is increased, and the voltage gain of the circuit is increased, so that the charging and discharging circuit can be applied to the bus of a single-phase inverter to charge and discharge the battery pack. Correspondingly, when the bus is the bus of a three-phase inverter, its bus voltage is a relatively high voltage, such as 600V-960V. As Figure 3 As shown, at this time, the first switch S1, the second switch S2, and the third switch S3 are disconnected, and the fourth switch S4 is turned on, so that the first transformer T1 and the second transformer T2 are in a series structure, the voltage value provided by the circuit to the battery pack is reduced, and the voltage gain of the circuit is reduced, so that the charge and discharge circuit 100 can be applied to the bus of the three-phase inverter to charge and discharge the battery pack.

[0034] The charging and discharging circuit proposed in the embodiment of the present invention is as follows: Figure 2 As shown, by adjusting the on and off relationship of the first switch, the second switch, the third switch and the fourth switch included in the circuit conversion device, the parallel and series relationship of the first DC converter and the second DC converter is adjusted. When the first DC converter and the second DC converter are connected in parallel, the equivalent turns ratio of the first transformer T1 and the first transformer T2 in parallel is N:1. When the input voltage is 360V-580V, S4 is disconnected and S1 S2 S3 is pulled in. The equivalent circuit is as follows Figure 2 As shown, the circuit can be adapted to the lower voltage of the single-phase inverter bus, such as Figure 3 As shown, when the first DC converter is connected in series with the second DC converter, the equivalent turns ratio of the first transformer T1 and the first transformer T2 in series is 2N:1, and when the input voltage is 600V-960V, S4 is energized and S1 S2 S3 are disconnected. The equivalent circuit is as follows Figure 3As shown, the circuit can adapt to the higher voltage of the three-phase inverter bus. The technical solution of the present application can make the circuit for charging and discharging the battery pack adapt to the bus voltage in a single-phase inverter environment and the bus voltage in a three-phase inverter environment without adjusting the circuit structure, thereby improving the adaptability of the circuit for charging and discharging the battery pack to different types of bus voltages;

[0035] Further, the circuit conversion device 110 also includes a first inductor L1 and a second inductor L2, wherein the first end of the first inductor L1 is connected to the DC positive electrode of the third main loop H bridge, the second end of the first inductor L1 is connected to the input end of the second transformer T2, the first end of the second inductor L2 is connected to the DC positive electrode of the third main loop H bridge, and the second end of the second inductor L2 is connected to the input end of the first transformer T1; the charging and discharging circuit can be filtered based on the inductor L1 to improve the stability of the circuit;

[0036] Further, the third main loop H bridge is respectively composed of a switch tube Q1, a switch tube Q2, a switch tube Q3, a switch tube Q4 and a third capacitor C3, the switch tube Q1 and the switch tube Q2 are located on one side of the main loop H bridge of the bus, the switch tube Q3 and the switch tube Q4 are located on the other side of the main loop H bridge of the bus, the switch tube Q1 and the switch tube Q2 are connected in series, the switch tube Q3 and the switch tube Q4 are connected in series, the switch tube Q1 and the switch tube Q3 are connected to the positive electrode of direct current, and the switch tube Q2 and the switch tube Q4 are connected to the negative electrode of direct current;

[0037] The first end of the first switch S1 is connected to the output of the connection midpoint between the switch tube Q1 and the switch tube Q2, and the second end of the second switch S2 is connected to the output of the connection midpoint between the switch tube Q3 and the switch tube Q4;

[0038] Further, the first main loop H bridge is composed of a switch tube Q5, a switch tube Q6, a switch tube Q7, a switch tube Q8 and a first capacitor C1, the switch tube Q5 and the switch tube Q6 are located on one side of the first main loop H bridge, the switch tube Q7 and the switch tube Q8 are located on the other side of the first main loop H bridge, the switch tube Q5 and the switch tube Q6 are connected in series, the switch tube Q7 and the switch tube Q8 are connected in series, the switch tube Q5 and the switch tube Q7 are connected to the positive electrode of direct current, and the switch tube Q6 and the switch tube Q8 are connected to the negative electrode of direct current;

[0039] The first end of the third switch S3 is connected to the input end of the first transformer T1, and the output end of the first transformer T1 is respectively connected to the connection midpoint output of the switch tube Q5 and the switch tube Q6 and the connection midpoint output of the switch tube Q7 and the switch tube Q8;

[0040] Further, the second main circuit H bridge is composed of a switch tube Q9, a switch tube Q10, a switch tube Q11, a switch tube Q12 and a second capacitor C2, the switch tube Q9 and the switch tube Q10 are located on one side of the second main circuit H bridge of the battery pack, the switch tube Q11 and the switch tube Q12 are located on the other side of the first main circuit H bridge, the switch tube Q9 and the switch tube Q10 are connected in series, the switch tube Q11 and the switch tube Q12 are connected in series, the switch tube Q9 and the switch tube Q11 are connected to the positive electrode of direct current, and the switch tube Q10 and the switch tube Q12 are connected to the negative electrode of direct current;

[0041] The second end of the second switch S2 is connected to the input end of the second transformer T2, and the output end of the second transformer T2 is respectively connected to the connection midpoint output of the switch tube Q9 and the switch tube Q10 and the connection midpoint output of the switch tube Q11 and the switch tube Q12;

[0042] It is worth noting that the battery pack transformer charging circuit of the present application adjusts the parallel and series relationship between the two transformers included in the circuit through the on and off relationship of the first switch, the second switch, the third switch and the fourth switch included in the circuit conversion device. When the first transformer is connected in parallel with the second transformer, the circuit can adapt to the lower voltage of the single-phase inverter bus. When the first transformer is connected in series with the second transformer, the circuit can adapt to the higher voltage of the three-phase inverter bus. The technical solution of the present application enables the circuit for charging and discharging the battery pack to adapt to the bus voltage in a single-phase inverter environment and the bus voltage in a three-phase inverter environment without adjusting the circuit structure, thereby improving the adaptability of the circuit for charging and discharging the battery pack to different types of buses.

[0043] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A battery pack voltage conversion charging circuit, used to connect between a battery pack and a bus bar, characterized in that: The battery pack voltage conversion charging circuit comprises: A first transformer, wherein the output end of the first transformer is connected to the first main circuit H bridge connected to the battery pack, and the positive electrode access end of the first transformer is connected to the DC positive electrode of the third main circuit H bridge connected to the busbar; a second transformer, wherein the output end of the second transformer is used to be connected to the second main circuit H bridge connected to the battery pack, and the input end of the second transformer is used to be connected to the negative pole of the direct current of the third main circuit H bridge connected to the busbar; A circuit conversion device, the circuit conversion device comprising a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4, wherein a first end of the first switch S1 is used to be connected to a DC positive electrode of the third main loop H bridge, and a second end of the first switch S1 is connected to an input end of the second transformer; The first end of the second switch S2 is connected to the input end of the first transformer, the output end of the first transformer is connected to the negative pole of the DC power of the first main loop H bridge, and the second end of the second switch S2 is used to connect to the negative pole of the DC power of the third main loop H bridge; A first end of the third switch S3 is connected to the input end of the first transformer, an output end of the first transformer is connected to the positive pole of the DC power of the first main circuit H bridge, a second end of the third switch is connected to the input end of the second transformer, and an output end of the second transformer is connected to the positive pole of the DC power of the second main circuit H bridge; A first end of the fourth switch S4 is connected to the input end of the second transformer, an output end of the second transformer is connected to the negative DC pole of the second main loop H bridge, and a second end of the fourth switch S4 is connected to the input end of the first transformer.

2. A battery pack voltage conversion charging circuit according to claim 1, characterized in that: The circuit conversion device also includes a first inductor L1 and a second inductor L2, wherein the first end of the first inductor L1 is connected to the DC positive pole of the third main loop H bridge, the second end of the first inductor L1 is connected to the input end of the second transformer T2, the first end of the second inductor L2 is connected to the DC positive pole of the third main loop H bridge, and the second end of the second inductor L2 is connected to the input end of the first transformer T1.

3. A battery pack voltage conversion charging circuit according to claim 1, characterized in that: The third main loop H bridge is respectively composed of a switch tube Q1, a switch tube Q2, a switch tube Q3, a switch tube Q4 and a third capacitor C3, wherein the switch tube Q1 and the switch tube Q2 are located on one side of the main loop H bridge of the bus, and the switch tube Q3 and the switch tube Q4 are located on the other side of the main loop H bridge of the bus, the switch tube Q1 and the switch tube Q2 are connected in series, the switch tube Q3 and the switch tube Q4 are connected in series, the switch tube Q1 and the switch tube Q3 are connected to the positive electrode of direct current, and the switch tube Q2 and the switch tube Q4 are connected to the negative electrode of direct current; The first end of the first switch S1 is connected to the connection midpoint output of the switch tube Q1 and the switch tube Q2, and the second end of the second switch S2 is connected to the connection midpoint output of the switch tube Q3 and the switch tube Q4.

4. A battery pack voltage conversion charging circuit according to claim 1, characterized in that: The first main loop H bridge is composed of a switch tube Q5, a switch tube Q6, a switch tube Q7, a switch tube Q8 and a first capacitor C1, wherein the switch tube Q5 and the switch tube Q6 are located on one side of the first main loop H bridge, and the switch tube Q7 and the switch tube Q8 are located on the other side of the first main loop H bridge, the switch tube Q5 and the switch tube Q6 are connected in series, the switch tube Q7 and the switch tube Q8 are connected in series, the switch tube Q5 and the switch tube Q7 are connected to the positive electrode of direct current, and the switch tube Q6 and the switch tube Q8 are connected to the negative electrode of direct current; The first end of the third switch S3 is connected to the input end of the first transformer, and the output end of the first transformer is respectively connected to the connection midpoint output of the switch tube Q5 and the switch tube Q6 and the connection midpoint output of the switch tube Q7 and the switch tube Q8.

5. A battery pack voltage conversion charging circuit according to claim 1, characterized in that: The second main circuit H bridge is composed of a switch tube Q9, a switch tube Q10, a switch tube Q11, a switch tube Q12 and a second capacitor C2. The switch tube Q9 and the switch tube Q10 are located on one side of the second main circuit H bridge of the battery pack, and the switch tube Q11 and the switch tube Q12 are located on the other side of the first main circuit H bridge. The switch tube Q9 and the switch tube Q10 are connected in series, and the switch tube Q11 and the switch tube Q12 are connected in series. The switch tube Q9 and the switch tube Q11 are connected to the positive electrode of direct current, and the switch tube Q10 and the switch tube Q12 are connected to the negative electrode of direct current; The second end of the second switch S2 is connected to the input end of the second transformer, and the output end of the second transformer is respectively connected to the connection midpoint output of the switch tube Q9 and the switch tube Q10 and the connection midpoint output of the switch tube Q11 and the switch tube Q12.

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