Charging device

Abstract

The utility model relates to the technical field of power supplies, and discloses a charging device. The charging device comprises a pre-stage rectification module, a post-stage inversion module and a voltage regulation module, wherein the post-stage inversion module comprises at least two paths of power conversion units which are connected in series; and one end of the voltage regulation module is connected with each power conversion unit, and the other end of the voltage regulation module is connected with the pre-stage rectification module. The output voltage of each path of power conversion unit is collected through the arranged voltage regulation module and is fed back to the pre-stage rectification module, so that each path of output of the pre-stage rectification module is regulated, and the problem that in the prior art, a multi-path series output voltage balance control scheme is too complex is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply, in particular to a charging device. BACKGROUND

[0002] With the development of power supply technology, especially in the field of new energy, in order to reduce the cost of using devices in circuit design, low voltage level power devices are usually preferred, and then the series connection is used in the output end to ensure the output of the required voltage.

[0003] Although the series connection can meet the use requirements, in the actual application process, the series connection cannot guarantee the consistency of the voltage of multiple outputs. Based on this, the current solution is to control the voltage of the output of the latter stage, but the existing control of the latter stage is too complex. CONTENT OF THE UTILITY MODEL

[0004] In view of this, the present application provides a charging device to solve the problem that the voltage control scheme of the multiple series outputs in the prior art is too complex.

[0005] The first aspect of the present application provides a charging device, comprising: a front-stage rectification module, a rear-stage inversion module and a voltage regulation module; the rear-stage inversion module comprises at least two power conversion units, and each power conversion unit is connected in series; one end of the voltage regulation module is connected with each power conversion unit, and the other end of the voltage regulation module is connected with the front-stage rectification module; the voltage regulation module is used to collect the output voltages of each power conversion unit and output corresponding regulation signals to control each output of the front-stage rectification module, so that the output voltages of each power conversion unit are consistent.

[0006] In a feasible implementation, the rear-stage inversion module further comprises at least one switching circuit, and the at least one switching circuit is arranged between two power conversion units to realize the series connection of the two adjacent power conversion units.

[0007] In a feasible implementation, the voltage regulation module comprises a PI controller connected with the front-stage rectification module and the output ends of each power conversion unit.

[0008] In a feasible implementation, the voltage regulation module comprises: a rear-stage acquisition unit connected with each power conversion unit and used to collect the output voltages on the output ends of each power conversion unit; and a front-stage control unit connected with the front-stage rectification module and the rear-stage acquisition unit and used to receive the output voltages of each power conversion unit transmitted by the rear-stage acquisition unit and output corresponding front-stage control signals to adjust each output of the front-stage rectification module.

[0009] In an implementation, the front-stage control unit is a voltage deviation control loop, which is connected with the rear-stage acquisition unit and the front-stage rectification module, and is configured to compare voltage difference between output voltage of each channel transmitted by the rear-stage acquisition unit and bus voltage, so as to adjust output of each channel of the front-stage rectification module.

[0010] In an implementation, the rear-stage acquisition unit comprises a voltage acquisition circuit.

[0011] The acquisition end of the voltage acquisition circuit is connected with the output end of each channel of the power conversion unit, and the output end of the voltage acquisition circuit is connected with the input end of the front-stage control unit.

[0012] In an implementation, the rear-stage acquisition unit further comprises a drive controller connected with the control end of each channel of the power conversion unit, and configured to output corresponding switch drive signals to the control end of each channel of the power conversion unit.

[0013] In an implementation, the front-stage rectification module is a Vienna rectifier or an E-type three-level rectifier or a T-type three-level rectifier.

[0014] In an implementation, the at least two power conversion units are all LLC converters or CLLC converters.

[0015] In an implementation, the at least two power conversion units comprise at least one LLC converter and at least one CLLC converter.

[0016] In the technical scheme provided in the application, the charging device comprises a front-stage rectification module, a rear-stage inversion module comprising at least two channels of power conversion units in series, and a voltage regulation module; one end of the voltage regulation module is connected with each channel of the power conversion unit, and the other end of the voltage regulation module is connected with the front-stage rectification module. The voltage regulation module is configured to acquire output voltage of each channel of the power conversion unit and feed back to the front-stage rectification module, so as to adjust output of each channel of the front-stage rectification module. This way is not only simple in structure and control principle, but also does not need to change the existing unbalanced control mode, greatly reducing the complexity of voltage regulation control of the rear-stage inversion module. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The first schematic diagram of the charging device provided in the embodiments of the application;

[0018] Figure 2 The second schematic diagram of the charging device provided in the embodiments of the application;

[0019] Figure 3A third schematic diagram of the charging device provided by the embodiment of the present application is provided;

[0020] Figure 4 A fourth schematic diagram of the charging device provided by the embodiment of the present application is provided;

[0021] Figure 5 A circuit schematic diagram of the charging device provided by the embodiment of the present application is provided;

[0022] Figure 6 A circuit schematic diagram of the E-type three-level rectifier provided by the embodiment of the present application is provided;

[0023] Figure 7 A circuit schematic diagram of the T-type three-level rectifier provided by the embodiment of the present application is provided;

[0024] Figure 8 A circuit schematic diagram of the LLC converter provided by the embodiment of the present application is provided;

[0025] Figure 9 A circuit schematic diagram of the CLLC converter provided by the embodiment of the present application is provided. DETAILED DESCRIPTION

[0026] The terms "first", "second", "third", "fourth" and the like in the description and in the claims of the present application, if any, of the above-described drawings, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of the terms so construed can interchange, under appropriate circumstances, with respect to the embodiments of the present application described herein, for example, a first element, component or step corresponding to a second element, component or step can be implemented as a second element, component or step corresponding to the first element, component or step unless otherwise specifically noted. Additionally, the terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise noted.

[0027] As shown in Figure 1 A charging device provided by the embodiment of the present application, the device comprises:

[0028] The front-stage rectification module 110 is configured to provide positive and negative bus voltages.

[0029] The back-stage inversion module 120 is configured to transform the electric energy in the positive and negative DC bus voltages based on the power demand of the load, and output multiple paths.

[0030] The voltage regulation module 130 is arranged on the side of the front-stage rectification module 110, and is used to collect each signal output by the rear-stage inversion module 120 and return to the front-stage rectification module 110, compare each signal with the voltage of the bus, and adjust the bus voltage of each output of the front-stage rectification module 110 based on the difference of the comparison, so as to make the output voltages of each power conversion unit consistent.

[0031] It should be noted that the rear-stage inversion module 120 includes at least two power conversion units 121, and the power conversion units 121 are connected in series; one end of the voltage regulation module 130 is connected with each power conversion unit 121, and the other end of the voltage regulation module 130 is connected with the front-stage rectification module 110.

[0032] It can be understood that the voltage regulation module 130 is provided with a plurality of collection ports, each of which is connected with the output end of a power conversion unit 121, and is used to monitor and collect the output voltage of each power conversion unit 121 in real time, identify whether each output voltage meets the balance condition, such as equal or unequal, and output a corresponding regulation signal to control each output of the front-stage rectification module 110 based on the identification result. Here, the control of each output of the front-stage rectification module 110 is actually to determine the bus voltage of each output of the front-stage rectification module 110 based on the identification result, and then output a signal to adjust the on and off time of the switch tube of each output of the front-stage rectification module 110, so as to adjust the determined bus voltage output to the rear-stage inversion module 120.

[0033] In the embodiment, the series connection between each power conversion unit 121 can be a fixed series connection, or a switch can be arranged to realize series control, that is, the rear-stage inversion module 120 further includes at least one switch circuit 122, the at least one switch circuit 122 is arranged between two power conversion units 121, and is used to realize the series connection of the adjacent two power conversion units 121, as shown in the following figure. Figure 2

[0034] It should be noted that the switch circuit 122 can be a common switch, such as a relay, a single knife switch, etc., and the user can determine the number of corresponding power conversion units 121 according to the actual power demand and manually close the switch. Of course, a power switch tube can also be used to realize this, and the control end of the power switch tube needs to be connected with the voltage regulation module 130.

[0035] ​In practical application, the voltage regulation module 130 can be a controller originally in the charging device for controlling the turn-on and turn-off of the switch tubes in the front-stage rectifying module 110 and the back-stage inverting module 120, or a separately added PI controller 131. If the original controller is used, it only needs to connect the I / O port in the controller to the output end of each power conversion unit 121, so that the controller can directly obtain the voltage at the output end of each power conversion unit 121, and compare the voltage at each output end. If they are equal, the front-stage rectifying module 110 does not need to be adjusted, and if they are not equal, the corresponding signal is output to adjust each output of the front-stage rectifying module 110. Of course, the output signal here is actually a group of signal sequences, and the turn-on and turn-off of all switch tubes are controlled based on the group of signal sequences.

[0036] The embodiment sets the output voltage of each power conversion unit by the voltage regulation module, and then adjusts each output in the front-stage rectifying module based on the voltage difference between each output voltage, so as to balance the voltage at the output end of each power conversion unit. Such a circuit structure not only has a simple circuit, but also has a low cost.

[0037] In a feasible implementation, the voltage regulation module 130 can further include two control units corresponding to the control of the front-stage and back-stage modules, as shown in Figure 3 The voltage regulation module 130 includes:

[0038] The back-stage acquisition unit 132 is connected with each of the power conversion units 121, and is used to acquire the output voltage at the output end of each of the power conversion units 121.

[0039] The front-stage control unit 133 is connected with the front-stage rectifying module 110 and the back-stage acquisition unit 132, and is used to receive the output voltage of each channel transmitted by the back-stage acquisition unit 132, and output the corresponding front-stage control signal to adjust each output of the front-stage rectifying module 110.

[0040] It should be noted that the back-stage acquisition unit 132 and the front-stage control unit 133 control the power conversion unit 121 and the front-stage rectifying module 110, respectively. Such a structure avoids mutual influence.

[0041] The front-stage control unit 133 is a voltage deviation control loop, which is connected with the output end of the rear-stage acquisition unit 132 and the input end of the front-stage rectification module 110. The voltage deviation control loop compares the voltage difference between the output voltage of each power conversion unit 121 transmitted by the rear-stage acquisition unit 132 and the bus voltage on the front-stage rectification module 110, outputs a control signal based on the comparison result of the voltage difference, and the front-stage rectification module 110 adjusts the bus voltage based on the control signal to realize the adjustment of each output.

[0042] In actual application, the front-stage rectification module 110 does not need to be adjusted every time the output voltages of the power conversion units 121 are compared. When the output voltages are determined to be unequal, the voltage difference between the two is further determined. If the voltage difference is within the allowed range, the adjustment can be skipped, and the output voltage at the next moment is collected, and the voltage difference is calculated, and then accumulated with the voltage difference at the previous moment. When the voltage difference exceeds the allowed range, the output signal adjusts the front-stage rectification module 110. It can be understood that the output signal corresponding to the voltage difference is used to control the voltage of the two bus bars in the front-stage rectification module 110, such as adjusting the positive and negative bus voltage values of the front-stage. Figure 5 As shown in the figure, when the DCDC_A voltage is higher than the DCDC_B voltage, the output voltages of the power conversion units DCDC_A and DCDC_B can be made consistent by adjusting the VbusP voltage to decrease and the VbusN voltage to increase.

[0043] Further, a voltage deviation adjustment loop can be set in the front-stage bus control loop to adjust each output of the front-stage rectification module 110 by using PI control to realize the voltage balance control of the output end of each power conversion unit 121.

[0044] In another embodiment, the rear-stage acquisition unit 132 includes a voltage acquisition circuit, the acquisition end of the voltage acquisition circuit is connected with the output end of each power conversion unit 121, and the output end of the voltage acquisition circuit is connected with the input end of the front-stage control unit 133, as shown in the figure. Figure 4

[0045] It should be noted that when the charging device does not need to consider the isolation between the front-stage and the rear-stage, the voltage acquisition circuit can directly acquire the voltage of the output end of each power conversion unit 121.

[0046] It can be one voltage acquisition circuit for each output end, or one voltage acquisition circuit for collecting each output end. When one voltage acquisition circuit is used, polling acquisition is needed.

[0047] ​The voltage acquisition circuit specifically comprises a signal acquisition circuit and a voltage comparison circuit, which are used for detecting and comparing the voltage difference of the output voltage of each power conversion unit 121 in real time, so as to ensure real-time voltage equalization.

[0048] In this embodiment, the post-stage acquisition unit 132 further comprises a driving controller connected with the control end of each of the power conversion units 121, which is used for outputting a corresponding switch driving signal to the control end of each of the power conversion units 121.

[0049] It can be understood that the pre-stage rectification module 110 provided herein is actually a rectifier, such as a VIENNA rectifier or an E-type three-level rectifier or a T-type three-level rectifier.

[0050] As shown in Figure 5 The specific circuit diagram of the pre-stage rectification module 110 adopting the VIENNA rectifier is shown in the figure, in which the power conversion unit 121 is provided with two, corresponding to DCDC_A and DCDC_B, and the post-stage acquisition unit 132 (corresponding to the DCDC control unit in the figure) acquires the output voltage of DCDC_A and DCDC_B and sends it to the pre-stage control unit 133 (corresponding to the VIENNA control unit in the figure) to calculate the voltage difference of the two, and adjust the difference of the positive and negative bus voltages in the pre-stage rectification module 110 based on the voltage difference, so that the output voltages of the two DCDC_A and DCDC_B are consistent.

[0051] In actual application, when the output voltages of DCDC_A and DCDC_B inside the post-stage inversion module 120 are inconsistent, the difference of the positive and negative bus voltages of the pre-stage rectification module 110 is adjusted to make the output voltages of DCDC_A and DCDC_B consistent.

[0052] When K3 in the control diagram is closed, so that each power conversion unit 121 is in series mode, due to the inconsistency of the internal devices of the post-stage inversion module 120, the output voltages of DCDC_A and DCDC_B are inconsistent, the voltage values of DCDC_A and DCDC_B can be transmitted to the VIENNA control unit by the DCDC control unit, and the VIENNA control unit adjusts the positive and negative bus voltage values of the pre-stage according to the voltage difference transmitted by the DCDC control unit, when the voltage of DCDC_A is higher than that of DCDC_B, the output voltages of DCDC_A and DCDC_B can be made consistent by reducing the VbusP voltage and increasing the VbusN voltage.

[0053] For example, the DCDC_A voltage value is 15V higher than the DCDC_B voltage value, and the VIENNA control unit collects the voltage offset value of 15V. A voltage offset control loop is superimposed on the front bus voltage control loop, and a PI is used to control the front bus, so as to adjust the voltage values of DCDC_A and DCDC_B. By adjusting the voltage values of the front bus voltage VbusP and VbusN, the output voltages of the DCDC_A and DCDC_B are equal. The method of adjusting the front offset to make the rear voltage equal makes the front power circuit not limited to the VIENNA rectifier, but can be other topological rectifier circuits, such as E-type three-level rectifier / T-type three-level rectifier, as shown in Figure 6 and 7 .

[0054] Further, in addition to the front stage not being limited, the power conversion unit 121 of the rear stage can also not be limited, such as LLC converter, CLLC converter, etc., as shown in Figure 8 and 9 . Even the power conversion unit 121 can also be a two-level LLC converter.

[0055] It should be noted that in order to facilitate the control of the consistent output voltage, it is preferred that each power conversion unit 121 is an LLC converter or a CLLC converter.

[0056] Of course, it can also be a mixture of LLC converter and CLLC converter, that is, the at least two power conversion units 121 include at least one LLC converter and at least one CLLC converter, and the adjacent two power conversion units 121 are set as LLC converter and CLLC converter. For this, the voltage adjustment is the same as the above-mentioned scheme, which will not be repeated here.

[0057] The embodiment provides a charging device. Without increasing the hardware cost, the voltage regulation loop of the rear-stage inverter module and the front-stage rectifier module is increased, so that the non-uniform voltage control of each power conversion unit in the rear stage becomes feasible. The difference between the output voltages of the rear stage is returned to the controller in the front-stage rectifier module for feedback control, thereby greatly reducing the complexity of the voltage control of each power conversion unit in the rear stage.

[0058] Finally, it should be noted that the above examples are merely specific embodiments of the present application, and are used to illustrate the technical solutions of the present application, but not to limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that, within the technical scope disclosed by the present application, any person skilled in the art can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A charging device, characterized by, include: The system consists of a front-end rectifier module, a back-end inverter module, and a voltage regulation module. The subsequent inverter module includes at least two power conversion units, and the power conversion units are connected in series. One end of the voltage regulation module is connected to each of the power conversion units, and the other end of the voltage regulation module is connected to the front-stage rectifier module. The voltage regulation module is used to collect the output voltage of each of the power conversion units and output a corresponding regulation signal to control each output of the front-stage rectifier module so that the output voltage of each of the power conversion units is consistent.

2. The charging device of claim 1, wherein, The downstream inverter module further includes at least one switching circuit, which is located between the two power conversion units to realize the series connection of the two adjacent power conversion units.

3. The charging device of claim 1, wherein, The voltage regulation module includes a PI controller, which is connected to the output terminals of the pre-rectifier module and each of the power conversion units.

4. The charging device of claim 1, wherein, The voltage regulation module includes: The subsequent acquisition unit is connected to each of the power conversion units and is used to acquire the output voltage at the output terminal of each of the power conversion units. A front-end control unit, which is connected to the front-end rectifier module and the rear-end acquisition unit, is used to receive the output voltage of each channel transmitted by the rear-end acquisition unit and output corresponding front-end control signals to adjust the output of each channel of the front-end rectifier module.

5. The charging device of claim 4, wherein, The front-end control unit is a voltage deviation control loop, which is connected to the back-end acquisition unit and the front-end rectifier module. It is used to compare the voltage difference between the output voltage of each channel transmitted from the back-end acquisition unit and the bus voltage, so as to adjust the output of each channel of the front-end rectifier module.

6. The charging device of claim 4, wherein, The subsequent acquisition unit includes: a voltage acquisition circuit; The voltage acquisition circuit's acquisition terminal is connected to the output terminal of each of the power conversion units, and the output terminal of the voltage acquisition circuit is connected to the input terminal of the front-end control unit.

7. The charging device of claim 6, wherein, The subsequent acquisition unit further includes a drive controller connected to the control terminal of each of the power conversion units, used to output corresponding switching drive signals to the control terminal of each of the power conversion units.

8. The charging device according to any one of claims 1 to 7, characterized in that, The pre-stage rectifier module is a Vienna rectifier, an E-type three-level rectifier, or a T-type three-level rectifier.

9. The charging device according to any one of claims 1 to 7, characterized in that, The at least two power conversion units are either LLC converters or CLLC converters.

10. The charging device according to any one of claims 1 to 7, characterized in that, The at least two power conversion units include at least one LLC converter and at least one CLLC converter.

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