A bidirectional voltage conversion circuit and a bidirectional voltage conversion system

Abstract

The utility model discloses a bidirectional voltage conversion circuit and a bidirectional voltage conversion system, comprising: a first power module, a first switch module, a bidirectional DC-to-DC converter, a second switch module and a second power module; the first switch module is respectively connected to the first power module and the high-voltage port of the bidirectional DC-to-DC converter, and the first switch module is used to control the first power module to be connected to the high-voltage port when turned on, and to control the first power module to be disconnected from the high-voltage port when turned off; the second switch module is respectively connected to the second power module and the low-voltage port of the bidirectional DC-to-DC converter, and the second switch module is used to control the second power module to be connected to the low-voltage port when turned on, and to control the second power module to be disconnected from the low-voltage port when turned off; wherein at least one of the first switch module and the second switch module is a bidirectional gallium nitride device. The bidirectional voltage conversion circuit of the utility model embodiment has low cost, small size and high efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a bidirectional voltage conversion circuit and a bidirectional voltage conversion system. Background Art

[0002] Bidirectional voltage conversion circuits are mainly used for energy transmission between two energy sources / loads and are widely used in new energy vehicles (between two energy storage batteries) and energy storage fields.

[0003] The existing bidirectional voltage conversion circuit has the problems of high cost, large size and low efficiency. Utility Model Content

[0004] The utility model provides a bidirectional voltage conversion circuit and a bidirectional voltage conversion system, which solve the problems of high cost, large volume and low efficiency of the existing bidirectional voltage conversion circuit, and can reduce cost, reduce volume and improve efficiency.

[0005] In a first aspect, an embodiment of the utility model provides a bidirectional voltage conversion circuit, including: a first power module, a first switch module, a bidirectional DC-to-DC converter, a second switch module and a second power module; the first switch module is respectively connected to the first power module and the high-voltage port of the bidirectional DC-to-DC converter, and the first switch module is used to control the first power module to be connected to the high-voltage port when turned on, and to control the first power module to be disconnected from the high-voltage port when turned off; the second switch module is respectively connected to the second power module and the low-voltage port of the bidirectional DC-to-DC converter, and the second switch module is used to control the second power module to be connected to the low-voltage port when turned on, and to control the second power module to be disconnected from the low-voltage port when turned off; wherein, at least one of the first switch module and the second switch module is a bidirectional gallium nitride device.

[0006] Optionally, the bidirectional voltage conversion circuit also includes a first driving module; the input end of the first driving module is connected to the first driving signal, the output end of the first driving module is connected to the control end of the first switch module, and the first driving module is used to control the first switch module to be turned on or off according to the first driving signal at its input end.

[0007] Optionally, the first switch module includes a first transistor; the first electrode of the first transistor is connected to the positive voltage output end of the first power supply module, the second electrode of the first transistor is connected to the high voltage port of the bidirectional DC-to-DC converter, and the gate of the first transistor serves as the control end of the first switch module.

[0008] Optionally, the bidirectional voltage conversion circuit also includes a second driving module; the input end of the second driving module is connected to the second driving signal, the output end of the second driving module is connected to the control end of the second switch module, and the second driving module is used to control the second switch module to be turned on or off according to the second driving signal at its input end.

[0009] Optionally, the second switch module includes a second transistor; the first electrode of the second transistor is connected to the positive voltage output end of the second power supply module, the second electrode of the second transistor is connected to the low voltage port of the bidirectional DC-to-DC converter, and the gate of the second transistor serves as the control end of the second switch module.

[0010] Optionally, the bidirectional DC-to-DC converter includes n bidirectional Buck-Boost conversion circuits, where n is an integer greater than or equal to 1; when the bidirectional DC-to-DC converter includes at least two bidirectional Buck-Boost conversion circuits, the at least two bidirectional Buck-Boost conversion circuits are connected in parallel.

[0011] Optionally, the bidirectional Buck-Boost conversion circuit includes a third transistor, a fourth transistor and an inductor; the first electrode of the third transistor serves as a high-voltage port, the second electrode of the third transistor is connected to the first end of the inductor, and the second end of the inductor serves as a low-voltage port; the first electrode of the fourth transistor is connected to the first end of the inductor, and the second electrode of the fourth transistor is grounded; wherein at least one of the third transistor and the fourth transistor is a gallium nitride device.

[0012] Optionally, the first switch module and the second switch module are both bidirectional gallium nitride devices, and the third transistor and the fourth transistor are both gallium nitride devices.

[0013] Optionally, the bidirectional Buck-Boost conversion circuit also includes a third drive module and a fourth drive module; the input end of the third drive module is connected to the first PWM control signal, the output end of the third drive module is connected to the gate of the third transistor, and the third drive module is used to control the third transistor to be turned on or off according to the first PWM control signal at its input end; the input end of the fourth drive module is connected to the second PWM control signal, the output end of the fourth drive module is connected to the gate of the fourth transistor, and the fourth drive module is used to control the fourth transistor to be turned on or off according to the second PWM control signal at its input end.

[0014] In a second aspect, an embodiment of the utility model provides a bidirectional voltage conversion system, including the bidirectional voltage conversion circuit provided by any embodiment of the utility model.

[0015] The bidirectional voltage conversion circuit provided by the embodiment of the utility model includes a first power module, a first switch module, a bidirectional DC-to-DC converter, a second switch module and a second power module. By setting at least one of the first switch module and the second switch module as a bidirectional gallium nitride device, that is, using a VGaN device to replace two back-to-back silicon devices with a common drain connection, the efficiency of the bidirectional voltage conversion circuit is improved, and the cost of the bidirectional voltage conversion circuit is reduced, and the volume of the bidirectional voltage conversion circuit is reduced.

[0016] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present utility model, nor are they intended to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a structural schematic diagram of a bidirectional voltage conversion circuit provided by an embodiment of the utility model;

[0019] Figure 2 It is a structural schematic diagram of another bidirectional voltage conversion circuit provided by an embodiment of the utility model;

[0020] Figure 3 It is a structural schematic diagram of another bidirectional voltage conversion circuit provided by an embodiment of the utility model;

[0021] Figure 4 It is a structural schematic diagram of another bidirectional voltage conversion circuit provided by an embodiment of the utility model;

[0022] Figure 5 This is a structural schematic diagram of another bidirectional voltage conversion circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0025] Figure 1 Schematic diagram of a bidirectional voltage conversion circuit provided by an embodiment of the utility model. Figure 1 As shown, the bidirectional voltage conversion circuit 100 includes: a first power module 11 , a first switch module 12 , a bidirectional DC-to-DC converter 13 , a second switch module 14 and a second power module 15 .

[0026] The first switch module 12 is connected to the first power module 11 and the high-voltage port P1 of the bidirectional DC-to-DC converter 13 respectively. The first switch module 12 is used to control the first power module 11 to be connected to the high-voltage port P1 when it is turned on, and to control the first power module 11 to be disconnected from the high-voltage port P1 when it is turned off.

[0027] The second switch module 14 is connected to the second power module 15 and the low voltage port P2 of the bidirectional DC-DC converter respectively. The second switch module 14 is used to control the second power module 15 to be connected to the low voltage port P2 when it is turned on, and to control the second power module 15 to be disconnected from the low voltage port P2 when it is turned off. At least one of the first switch module 12 and the second switch module 14 is a bidirectional gallium nitride device.

[0028] In some embodiments, the first power module 11 includes a battery pack, which provides a constant voltage for the bidirectional DC-DC converter 13. The voltage value provided by the battery pack is determined according to actual needs, and the embodiment of the utility model is not limited here, as long as it is greater than the voltage provided by the second power module 15. Optionally, the voltage provided by the constant voltage source is greater than 12V and less than or equal to 100V, for example, the voltage provided can be 24V, 36V or 48V, etc.

[0029] In some embodiments, the second power module 15 includes a battery pack, which provides a constant voltage for the bidirectional DC-DC converter 13. The voltage value provided by the battery pack is determined according to actual needs, and the embodiment of the utility model is not limited here, as long as it is less than the voltage provided by the first power module 11. Optionally, the voltage provided by the constant voltage source is greater than 0V and less than or equal to 12V, for example, the voltage provided can be 1V, 2V, 4V, 8V or 12V, etc.

[0030] The embodiment of the utility model does not specifically limit the structure of the bidirectional DC-DC converter 13, as long as it can achieve bidirectional energy transmission. Exemplarily, the bidirectional DC-DC converter 13 can be a bidirectional Buck-Boost conversion circuit, or other circuit topologies, such as an isolated CLLC resonant circuit. The bidirectional DC-DC converter 13 can operate in Buck mode or Boost mode.

[0031] When the bidirectional DC-to-DC converter 13 works in Buck mode, the bidirectional DC-to-DC converter 13 converts the first voltage output by the first power module 11 into the second voltage output by the second power module 15. For example, the first voltage is a 48V DC voltage, and the second voltage is a 12V DC voltage. When the bidirectional DC-to-DC converter 13 works in Buck mode, the bidirectional DC-to-DC converter 13 can convert the 48V DC voltage into a 12V DC voltage.

[0032] When the bidirectional DC-to-DC converter 13 works in the Boost mode, the bidirectional DC-to-DC converter 13 converts the second voltage output by the second power module 15 into the first voltage output by the first power module 11. The first voltage is greater than the second voltage. For example, the first voltage is a 48V DC voltage, and the second voltage is a 12V DC voltage. When the bidirectional DC-to-DC converter 13 works in the Boost mode, the bidirectional DC-to-DC converter 13 can convert the 12V DC voltage into a 48V DC voltage.

[0033] The first switch module 12 is used to cut off the connection between the first power module 11 and the bidirectional DC-DC converter 13 when the bidirectional voltage conversion circuit 100 fails. For example, when the voltage of the high-voltage port is greater than the first voltage or the first power module 11 is short-circuited, the first switch module 12 is turned off.

[0034] The second switch module 14 is used to cut off the connection between the second power module 15 and the bidirectional DC-DC converter 13 when the bidirectional voltage conversion circuit 100 fails. For example, when the voltage of the low voltage port is greater than the second voltage or the second power module 15 is short-circuited, the second switch module 14 is turned off.

[0035] At least one of the first switch module 12 and the second switch module 14 uses a bidirectional gallium nitride (VGaN) device. Compared with silicon devices, VGaN devices have higher critical electric field strength, lower on-state resistance, faster switching frequency, and can achieve higher efficiency. In the related art, the first switch module 12 and the second switch module 14 require two silicon devices to be connected in series back to back, which makes the first switch module 12 and the second switch module 14 larger in size and higher in cost. Moreover, since the on-resistance of the two silicon devices is connected in series, the on-resistance is large, resulting in serious heating. It is necessary to install a relatively high-power heat sink or air cooler to control the device temperature within a reasonable range, which further increases the volume of the bidirectional voltage conversion circuit 100. At least one of the first switch module 12 and the second switch module 14 of the embodiment of the utility model uses a bidirectional gallium nitride device, that is, a VGaN device is used to replace two back-to-back silicon devices connected with a common drain, which reduces the volume of the first switch module 12 and / or the second switch module 14, reduces the cost, and improves the efficiency of the bidirectional voltage conversion circuit 100.

[0036] The bidirectional voltage conversion circuit provided by the embodiment of the utility model includes a first power module, a first switch module, a bidirectional DC-to-DC converter, a second switch module and a second power module. By setting at least one of the first switch module and the second switch module as a bidirectional gallium nitride device, that is, using a VGaN device to replace two back-to-back silicon devices with a common drain connection, the voltage conversion efficiency of the bidirectional voltage conversion circuit is improved, and the cost of the bidirectional voltage conversion circuit is reduced, and the volume of the bidirectional voltage conversion circuit is reduced.

[0037] Figure 2 Schematic diagram of another bidirectional voltage conversion circuit provided by the embodiment of the utility model. Figure 2 As shown, the bidirectional voltage conversion circuit 100 also includes a first driving module 16, the input end of the first driving module 16 is connected to the first driving signal Dr1, the output end of the first driving module 16 is connected to the control end of the first switch module 12, and the first driving module 16 is used to control the first switch module 12 to be turned on or off according to the first driving signal Dr1 at its input end.

[0038] Specifically, the bidirectional voltage conversion circuit 100 further includes a control module 17, which can be implemented by a control device such as a microcontroller unit (MCU), a digital signal processor (DSP), or a field programmable gate array (FPGA). The control module 17 can also be an application-specific integrated circuit (ASIC). The control module 17 can obtain the first drive signal Dr1 by programming.

[0039] The first driving module 16 converts the first driving signal Dr1 into high and low level signals required by the first switch module 12. Optionally, the first driving module 16 includes a PWM driving chip and a peripheral circuit.

[0040] Based on the above embodiments, continue to refer to Figure 2 Optionally, the first switch module 12 includes a first transistor Q1, a first electrode of the first transistor Q1 is connected to the positive voltage output end of the first power supply module 11, a second electrode of the first transistor Q1 is connected to the high voltage port P1 of the bidirectional DC-to-DC converter 13, and a gate of the first transistor Q1 serves as a control end of the first switch module 12.

[0041] Optionally, the first transistor Q1 is a bidirectional gallium nitride device. In the embodiment of the utility model, by setting the first transistor Q1 as a bidirectional gallium nitride device, without using two back-to-back silicon devices with a common drain connection, the volume of the first switch module 12 can be reduced, and the cost of the first switch module 12 can be reduced, thereby reducing the volume of the bidirectional voltage conversion circuit 100, reducing the cost of the bidirectional voltage conversion circuit 100, and improving the efficiency of the bidirectional voltage conversion circuit 100.

[0042] Figure 3 Schematic diagram of another bidirectional voltage conversion circuit provided by the embodiment of the utility model. Figure 3 As shown, the bidirectional voltage conversion circuit 100 also includes a second driving module 18, the input end of the second driving module 18 is connected to the second driving signal Dr2, the output end of the second driving module 18 is connected to the control end of the second switch module 14, and the second driving module 18 is used to control the second switch module 14 to be turned on or off according to the second driving signal Dr2 at its input end.

[0043] Specifically, the bidirectional voltage conversion circuit 100 further includes a control module 17, and the control module 17 can obtain the second drive signal Dr2 by programming. The second drive module 18 converts the first drive signal Dr2 into high and low level signals required by the second switch module 14. Optionally, the second drive module 18 includes a PWM drive chip and a peripheral circuit.

[0044] Based on the above embodiments, continue to refer to Figure 3 Optionally, the second switch module 14 includes a second transistor Q2, a first electrode of the second transistor Q2 is connected to the positive voltage output end of the second power supply module 15, a second electrode of the second transistor Q2 is connected to the low voltage port P1 of the bidirectional DC-to-DC converter 13, and a gate of the second transistor Q2 serves as a control end of the second switch module 15.

[0045] Optionally, the second transistor Q2 is a bidirectional gallium nitride device. The embodiment of the utility model sets the second transistor Q2 as a bidirectional gallium nitride device without using two back-to-back silicon devices with a common drain connection, thereby reducing the volume of the second switch module 14 and reducing the cost of the second switch module 14, thereby reducing the volume of the bidirectional voltage conversion circuit, reducing the cost of the bidirectional voltage conversion circuit, and improving the efficiency of the bidirectional voltage conversion circuit.

[0046] Figure 4 Schematic diagram of another bidirectional voltage conversion circuit provided by the embodiment of the utility model. Figure 4 As shown, the bidirectional DC-to-DC converter 13 includes n bidirectional Buck-Boost conversion circuits 130, where n is an integer greater than or equal to 1. When the bidirectional DC-to-DC converter 13 includes at least two bidirectional Buck-Boost conversion circuits 130, the at least two bidirectional Buck-Boost conversion circuits 130 are connected in parallel.

[0047] Based on the above embodiments, continue to refer to Figure 4 Optionally, the bidirectional Buck-Boost conversion circuit 130 includes a third transistor, a fourth transistor and an inductor.

[0048] The first electrode of the third transistor serves as the high voltage port P1 , the second electrode of the third transistor is connected to the first end of the inductor, and the second end of the inductor serves as the low voltage port P2 .

[0049] A first electrode of the fourth transistor is connected to the first end of the inductor, and a second electrode of the fourth transistor is grounded.

[0050] Among them, at least one of the third transistor and the fourth transistor is a gallium nitride device. GaN transistors have higher critical electric field strength, lower on-state resistance, faster switching frequency, can achieve higher system efficiency and work at high temperatures. The embodiment of the utility model can reduce the volume of the bidirectional DC-to-DC converter 13 and reduce the cost of the bidirectional DC-to-DC converter 13 compared to using silicon devices by setting at least one of the third transistor and the fourth transistor as a gallium nitride (GaN) device, thereby reducing the volume of the bidirectional voltage conversion circuit, reducing the cost of the bidirectional voltage conversion circuit, and improving the efficiency of the bidirectional voltage conversion circuit.

[0051] In some embodiments, continue to refer to Figure 4 The bidirectional DC-to-DC converter 13 includes a first bidirectional Buck-Boost conversion circuit 131 and a second bidirectional Buck-Boost conversion circuit 132. The first bidirectional Buck-Boost conversion circuit 131 includes a first third transistor Q3-1, a first fourth transistor Q4-1 and a first inductor L1. The second bidirectional Buck-Boost conversion circuit 132 includes a second third transistor Q3-2, a second fourth transistor Q4-2 and a second inductor L2.

[0052] Based on the above embodiment, optionally, continue to refer to Figure 4 , the first switch module 12 and the second switch module 14 are both bidirectional gallium nitride devices, and the third transistor and the fourth transistor are both gallium nitride devices. Such an arrangement can reduce the volume of the first switch module 12, the second switch module 14 and the bidirectional DC-to-DC converter 13, and reduce the cost of the first switch module 12, the second switch module 14 and the bidirectional DC-to-DC converter 13, thereby reducing the volume of the bidirectional voltage conversion circuit, reducing the cost of the bidirectional voltage conversion circuit, and improving the efficiency of the bidirectional voltage conversion circuit.

[0053] Based on the above embodiment, optionally, continue to refer to Figure 4 The bidirectional Buck-Boost conversion circuit 130 also includes a third driving module and a fourth driving module.

[0054] The input end of the third driving module is connected to the first PWM control signal, the output end of the third driving module is connected to the gate of the third transistor, and the third driving module is used to control the third transistor to be turned on or off according to the first PWM control signal at its input end.

[0055] The input end of the fourth driving module is connected to the second PWM control signal, the output end of the fourth driving module is connected to the gate of the fourth transistor, and the fourth driving module is used to control the fourth transistor to be turned on or off according to the second PWM control signal at its input end.

[0056] Specifically, the bidirectional voltage conversion circuit 100 further includes a control module 17, and the control module 17 can obtain multiple groups of first PWM control signals and multiple groups of second PWM control signals by programming. When the control module 17 is an analog control chip, no programming is required, and multiple groups of first PWM control signals and multiple groups of second PWM control signals can be directly output. Each bidirectional Buck-Boost conversion circuit 130 corresponds to a group of first PWM control signals and a second PWM control signal.

[0057] The first bidirectional Buck-Boost conversion circuit 131 includes a first third driving module 191 and a first fourth driving module 201. The input end of the first third driving module 191 is connected to the first first PWM control signal PWM1-1. The first fourth driving module 201 is connected to the first second PWM control signal PWM2-1.

[0058] The second bidirectional Buck-Boost conversion circuit 131 includes a second third driving module 192 and a second fourth driving module 202. The input end of the second third driving module 192 is connected to the second first PWM control signal PWM1-2. The second fourth driving module 201 is connected to the second second PWM control signal PWM2-2.

[0059] It should be noted that the waveforms of the first first PWM control signal PWM1-1 and the first second PWM control signal PWM2-1 are different from the waveforms of the second first PWM control signal PWM1-2 and the second second PWM control signal PWM2-2. For example, the first first PWM control signal PWM1-1 and the first second PWM control signal PWM2-1 lag behind or lead the second first PWM control signal PWM1-2 and the second second PWM control signal PWM2-2 by 180 degrees, respectively.

[0060] The third driving module converts the first PWM control signal into the high and low level signals required by the third transistor. The fourth driving module converts the second PWM control signal into the high and low level signals required by the fourth transistor. Optionally, the structures of the first driving module 16, the second driving module 18, the third driving module and the fourth driving module may be the same or different. Exemplarily, the first driving module 16, the second driving module 18, the third driving module and the fourth driving module all include a PWM driving chip and a peripheral circuit. The peripheral circuit is an auxiliary circuit for the PWM driving chip, and realizes the driving function together with the PWM driving chip. For example, the peripheral circuit may include components such as resistors and capacitors.

[0061] Figure 5 Schematic diagram of another bidirectional voltage conversion circuit provided by the embodiment of the utility model. Figure 5 As shown, the bidirectional voltage conversion circuit includes: a first power module 11, a first switch module 12, a bidirectional DC-to-DC converter 13, a second switch module 14 and a second power module 15.

[0062] The first switch module 12 includes a first transistor Q1 , and the second switch module 14 includes a second transistor Q2 . The bidirectional voltage conversion circuit 100 further includes a first driving module 16 , a control module 17 and a second driving module 18 .

[0063] The bidirectional DC-to-DC converter 13 includes n bidirectional Buck-Boost conversion circuits 130, where n is an integer greater than or equal to 1. Optionally, the bidirectional Buck-Boost conversion circuit 130 includes a third transistor, a fourth transistor and an inductor. Optionally, the bidirectional Buck-Boost conversion circuit also includes a third drive module and a fourth drive module.

[0064] Exemplarily, the bidirectional DC-to-DC converter 13 includes a first bidirectional Buck-Boost conversion circuit 131 and a second bidirectional Buck-Boost conversion circuit 132. The first bidirectional Buck-Boost conversion circuit 131 includes a first third transistor Q3-1, a first fourth transistor Q4-1, and a first inductor L1. The second bidirectional Buck-Boost conversion circuit 132 includes a second third transistor Q3-2, a second fourth transistor Q4-2, and a second inductor L2.

[0065] The first switch module 12 and the second switch module 14 of the utility model embodiment use a VGaN device to replace two back-to-back silicon devices with a common drain connection, which can reduce the number of components in the first switch module 12 and the second switch module 14 by 50%, increase the efficiency by 2%, reduce the volume by 20%, and reduce the cost by 20%. The transistors in the bidirectional DC-to-DC converter 13 of the utility model embodiment use gallium nitride devices, and the efficiency of the bidirectional DC-to-DC converter 13 is increased by 2%, the volume is reduced by 60%, and the cost is reduced by 10%. The efficiency of the entire bidirectional voltage conversion circuit can be increased by more than 2%, the volume can be reduced by 50%, and the cost can be reduced by about 15%.

[0066] Based on the above embodiments, continue to refer to Figure 5 Optionally, the bidirectional Buck-Boost conversion circuit 13 also includes a current acquisition module, a first end of the current acquisition module is connected to the second end of the inductor, and a second end of the current acquisition module is connected to the input end of the control module 17, for collecting the output current of the bidirectional Buck-Boost conversion circuit 130.

[0067] The first end of the first current acquisition module in the first bidirectional Buck-Boost conversion circuit 131 is connected to the first inductor L1, and the second end of the first current acquisition module is connected to the first input terminal Is1 of the control module 17. The first end of the second current acquisition module in the second bidirectional Buck-Boost conversion circuit 132 is connected to the second inductor L2, and the second end of the second current acquisition module is connected to the second input terminal Is2 of the control module 17.

[0068] It can be understood that the current acquisition module can be an additional current measuring instrument, or it can be a current acquisition module integrated on the same circuit board as the bidirectional Buck-Boost conversion circuit 130, or it can be a processor chip with a current sampling pin. The specific method can be determined according to the needs of the actual test scenario, as long as it can be used to collect the output current of the bidirectional Buck-Boost conversion circuit 130.

[0069] In some embodiments, the current acquisition module includes a sampling resistor, which converts the output current of the bidirectional Buck-Boost conversion circuit 130 into an output voltage and transmits it to the control module 17. The control module 17 obtains the current flowing through the sampling resistor through Ohm's law, and then obtains the output current of the bidirectional Buck-Boost conversion circuit 130.

[0070] In some embodiments, the control module 17 can calculate the average value of the output current of each bidirectional Buck-Boost conversion circuit 130 according to the output current of each bidirectional Buck-Boost conversion circuit 130, and compare the output current of each bidirectional Buck-Boost conversion circuit 130 with the average value.

[0071] Exemplarily, the bidirectional DC-to-DC converter 13 includes a first bidirectional Buck-Boost conversion circuit 131 and a second bidirectional Buck-Boost conversion circuit 132. The output current of the first bidirectional Buck-Boost conversion circuit 131 is greater than the average value, and the output current of the second bidirectional Buck-Boost conversion circuit 132 is less than the average value. At this time, the control module 17 can control the frequency and / or amplitude of the output first PWM control signal and / or the second PWM control signal. For example, the control module 17 can reduce the amplitude of the first PWM control signal and / or the second PWM control signal corresponding to the first bidirectional Buck-Boost conversion circuit 131, and increase the amplitude of the first PWM control signal and / or the second PWM control signal corresponding to the second bidirectional Buck-Boost conversion circuit 132, thereby reducing the output voltage of the first bidirectional Buck-Boost conversion circuit 131 and increasing the output voltage of the second bidirectional Buck-Boost conversion circuit 132, thereby reducing the output current of the first bidirectional Buck-Boost conversion circuit 131 and increasing the output current of the second bidirectional Buck-Boost conversion circuit 132, so as to achieve current sharing of the first bidirectional Buck-Boost conversion circuit 131 and the second bidirectional Buck-Boost conversion circuit 132.

[0072] The control module 17 can also stop outputting the first PWM control signal and the second PWM control signal when the output current of the bidirectional Buck-Boost conversion circuit 130 is greater than the set value, so as to protect the bidirectional Buck-Boost conversion circuit 130 from being damaged by the large current. Exemplarily, when the output current of the first bidirectional Buck-Boost conversion circuit 131 is greater than the set value, the control module 17 can stop outputting the first PWM control signal and the second PWM control signal corresponding to the first bidirectional Buck-Boost conversion circuit 131.

[0073] Based on the same utility model concept, the utility model also provides a bidirectional voltage conversion system, which includes the bidirectional voltage conversion circuit provided by any of the above embodiments, and has the functional modules and beneficial effects of any of the above embodiments, which will not be described in detail in this embodiment. Exemplarily, the bidirectional voltage conversion system can be an energy storage system and a battery management system, etc., which is not specifically limited in the embodiments of the utility model.

[0074] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A bidirectional voltage conversion circuit, characterized in that: include: A first power module, a first switch module, a bidirectional DC-to-DC converter, a second switch module, and a second power module; The first switch module is connected to the first power module and the high-voltage port of the bidirectional DC-to-DC converter respectively, and the first switch module is used to control the first power module to be connected to the high-voltage port when it is turned on, and to control the first power module to be disconnected from the high-voltage port when it is turned off; The second switch module is connected to the second power module and the low-voltage port of the bidirectional DC-DC converter respectively, and the second switch module is used to control the second power module to be connected to the low-voltage port when it is turned on, and to control the second power module to be disconnected from the low-voltage port when it is turned off; Wherein, at least one of the first switch module and the second switch module is a bidirectional gallium nitride device.

2. The bidirectional voltage conversion circuit according to claim 1, characterized in that: The bidirectional voltage conversion circuit also includes a first driving module; The input end of the first driving module receives a first driving signal, the output end of the first driving module is connected to the control end of the first switch module, and the first driving module is used to control the first switch module to be turned on or off according to the first driving signal at its input end.

3. The bidirectional voltage conversion circuit according to claim 2, characterized in that: The first switch module includes a first transistor; The first electrode of the first transistor is connected to the positive voltage output end of the first power supply module, the second electrode of the first transistor is connected to the high voltage port of the bidirectional DC-to-DC converter, and the gate of the first transistor serves as the control end of the first switch module.

4. The bidirectional voltage conversion circuit according to claim 1, characterized in that: The bidirectional voltage conversion circuit also includes a second driving module; The input end of the second driving module receives the second driving signal, the output end of the second driving module is connected to the control end of the second switch module, and the second driving module is used to control the second switch module to turn on or off according to the second driving signal at its input end.

5. The bidirectional voltage conversion circuit according to claim 4, characterized in that: The second switch module includes a second transistor; The first electrode of the second transistor is connected to the positive voltage output end of the second power supply module, the second electrode of the second transistor is connected to the low voltage port of the bidirectional DC-to-DC converter, and the gate of the second transistor serves as the control end of the second switch module.

6. The bidirectional voltage conversion circuit according to claim 1, characterized in that: The bidirectional DC-to-DC converter comprises n bidirectional Buck-Boost conversion circuits, where n is an integer greater than or equal to 1; When the bidirectional DC-to-DC converter includes at least two bidirectional Buck-Boost conversion circuits, at least two of the bidirectional Buck-Boost conversion circuits are connected in parallel.

7. The bidirectional voltage conversion circuit according to claim 6, characterized in that: The bidirectional Buck-Boost conversion circuit includes a third transistor, a fourth transistor and an inductor; The first electrode of the third transistor serves as the high-voltage port, the second electrode of the third transistor is connected to the first end of the inductor, and the second end of the inductor serves as the low-voltage port; A first electrode of the fourth transistor is connected to a first end of the inductor, and a second electrode of the fourth transistor is grounded; Wherein, at least one of the third transistor and the fourth transistor is a gallium nitride device.

8. The bidirectional voltage conversion circuit according to claim 7, characterized in that: The first switch module and the second switch module are both bidirectional gallium nitride devices, and the third transistor and the fourth transistor are both gallium nitride devices.

9. The bidirectional voltage conversion circuit according to claim 7, characterized in that: The bidirectional Buck-Boost conversion circuit also includes a third driving module and a fourth driving module; The input end of the third driving module is connected to the first PWM control signal, the output end of the third driving module is connected to the gate of the third transistor, and the third driving module is used to control the third transistor to be turned on or off according to the first PWM control signal at its input end; The input end of the fourth driving module is connected to the second PWM control signal, the output end of the fourth driving module is connected to the gate of the fourth transistor, and the fourth driving module is used to control the fourth transistor to be turned on or off according to the second PWM control signal at its input end.

10. A bidirectional voltage conversion system, characterized in that: The invention comprises the bidirectional voltage conversion circuit as described in any one of claims 1 to 9.

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