Charging module voltage-sharing device

Abstract

The invention relates to charging module voltage-sharing equipment, which comprises a voltage difference sampling and comparing device used for sampling the voltage difference between a first-stage series capacitor and a second-stage series capacitor of a charging module, and generating a first voltage-sharing control signal or a second voltage-sharing control signal based on the voltage difference and a preset threshold range; and a voltage-sharing control device. The voltage-sharing control device comprises a driving signal generation module, an energy storage capacitor, a first transformer driving module and a second transformer driving module; according to the invention, the energy storage capacitor can be successively connected in parallel with the first-stage series capacitor and the second-stage series capacitor so as to realize energy transfer voltage sharing from the first-stage series capacitor to the second-stage series capacitor or energy transfer voltage sharing from the second-stage series capacitor to the first-stage series capacitor. Therefore, the excitation source of the charging module does not need to be used, and two-stage series capacitor voltage sharing of the charging module can be realized in each mode of the charging module.

Description

Technical Field

[0001] The present invention relates to the field of charging modules, and more particularly to a charging module voltage equalizing device. Background Art

[0002] When using a high-voltage output in a car charging module, a two-stage converter is typically connected in series to achieve this high-voltage output. Ideally, the output voltages of the two stages should be identical, with each stage providing half the output voltage. However, due to differences in component parameters, the two output voltages are generally not completely identical. This results in unbalanced output power after the series connection, posing a risk to device thermal stress and reliability. Existing solutions use the half-bridge node of the main power circuit as the conversion oscillator source, stimulating an LC circuit for energy transfer to achieve voltage balancing. Figure 1 This is a circuit diagram of a charging module and its voltage equalization circuit in the prior art. Figure 1 As shown, the charging module includes an ACDC converter module 1 and a DCDC converter module 2. The DCDC converter module 2 includes full-bridge switching transistors Q11-Q24, full-bridge switching transistors Q1-Q8, series capacitors EC3 and EC4. The voltage equalizing circuit 3 includes an LC circuit and diodes D1-D8, wherein the LC circuit includes capacitors C8-C11 and inductors L8-L11. When the voltage of series capacitor EC3 is high and the voltage of series capacitor EC4 is low, during the conduction period of diagonal switching transistors Q11 and Q14, the high voltage of series capacitor EC3 is also applied between capacitor C11, inductor L11, and diode D5. Under the stimulation of the voltage of the series capacitor EC3, the capacitor C11 and the inductor L11 begin to accumulate energy. After half a cycle, the switch tubes Q11 and Q14 are turned off. At the same time, another set of switch tubes Q12 and Q13 located on the diagonal line are turned on. The capacitor C11 and the inductor L11 are connected in parallel to the two ends of the series capacitor EC4 through the diode D6. Since the voltage of the capacitor C11 comes from the series capacitor EC3, it is relatively high. Therefore, the capacitor C11 and the inductor L11 charge the series capacitor EC4 through the diode D6 to realize the energy transfer. The situation is the same for the midpoints of the other three half-bridges. Therefore, in the voltage balancing circuit of the prior art, the excitation source is the square wave voltage of the midpoints of the four half-bridges. However, after the charging module enters the intermittent mode due to light load, the excitation source disappears, and the voltage balancing circuit 3 fails. Therefore, the defect of this design is that after the charging module enters the intermittent mode due to load reduction, the excitation LC circuit will fail, causing the voltage difference between the two series capacitors of the charging module to be too high. Summary of the Invention The technical problem to be solved by the present invention is to provide a charging module voltage equalizing device in response to the above-mentioned defects of the prior art, which can also achieve two-stage series capacitor voltage equalization of the charging module after the charging module enters the intermittent mode due to load reduction.

[0003] The technical solution adopted by the present invention to solve the technical problem is to construct a charging module voltage equalizing device, including: a pressure difference sampling and comparison device, configured to sample the pressure difference between the first-stage series capacitor and the second-stage series capacitor of the charging module, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the pressure difference and a preset threshold range; and A voltage balancing control device, comprising a drive signal generating module, an energy storage capacitor, a first transformer driving module, and a second transformer driving module; The drive signal generating module generates a first drive signal and a second drive signal based on the first voltage balancing control signal or the second voltage balancing control signal respectively; the first transformer driving module and the second transformer driving module are turned on successively based on the first drive signal so that the energy storage capacitor is connected in parallel with the first-level series capacitor and the second-level series capacitor in turn to achieve energy transfer and voltage balancing from the first-level series capacitor to the second-level series capacitor; or the second transformer driving module and the first transformer driving module are turned on successively based on the second drive signal so that the energy storage capacitor is connected in parallel with the second-level series capacitor and the first-level series capacitor in turn to achieve energy transfer and voltage balancing from the second-level series capacitor to the first-level series capacitor.

[0004] In the charging module voltage balancing device of the present invention, the driving signal generating module includes a microcontroller; the first driving signal includes a complementary first square wave signal and a second square wave signal; the second driving signal includes a complementary third square wave signal and a fourth square wave signal; The driving signal generating module generates a first driving signal and a second driving signal based on the first voltage balancing control signal or the second voltage balancing control signal, respectively, including: The microcontroller generates the first square wave signal and the second square wave signal based on the first voltage-sharing control signal, and sends the first square wave signal to the first transformer driving module and sends the second square wave signal to the second transformer driving module; The microcontroller generates the third square wave signal and the fourth square wave signal based on the second voltage-sharing control signal, and sends the third square wave signal to the first transformer driving module and sends the fourth square wave signal to the second transformer driving module.

[0005] In the charging module voltage balancing device of the present invention, the first square wave signal is at a high level in the first half cycle and at a low level in the second half cycle, and the second square wave signal is at a low level in the first half cycle and at a high level in the second half cycle; The third square wave signal is at a low level in the first half of its cycle and at a high level in the second half of its cycle. The fourth square wave signal is at a high level in the first half of its cycle and at a low level in the second half of its cycle.

[0006] In the charging module voltage equalizing device described in the present invention, the capacitance values ​​of the first-stage series capacitor and the second-stage series capacitor are equal, and the capacitance value of the energy storage capacitor is less than one tenth of the capacitance value of the first-stage series capacitor or the second-stage series capacitor.

[0007] In the charging module voltage balancing device of the present invention, the first transformer driving module includes a first transformer, a first driving unit, a second driving unit, and a third driving unit; the first driving unit is connected to one side of the primary winding of the first transformer, the second driving unit is connected to one side of the first secondary winding of the first transformer, and the third driving unit is connected to one side of the second secondary winding of the first transformer; The second transformer driving module includes a second transformer, a fourth driving unit, a fifth driving unit and a sixth driving unit; the fourth driving unit is connected to one side of the primary winding of the second transformer, the fifth driving unit is connected to one side of the first secondary winding of the second transformer, and the sixth driving unit is connected to one side of the second secondary winding of the second transformer; A first end of the energy storage capacitor is connected to the second drive unit and the sixth drive unit, and a second end is connected to the third drive unit and the fifth drive unit; The first transformer driving module and the second transformer driving module are sequentially turned on based on the first driving signal so that the energy storage capacitor is sequentially connected in parallel with the first-stage series capacitor and the second-stage series capacitor to achieve energy transfer and voltage balancing from the first-stage series capacitor to the second-stage series capacitor, including: The first drive unit is turned on based on the first square wave signal to drive the second drive unit and the third drive unit to be turned on, the energy storage capacitor is connected in parallel with the first-stage series capacitor so that the first-stage series capacitor charges the energy storage capacitor, and then the second drive unit and the third drive unit are turned off, the fourth drive unit is turned on based on the second square wave signal to drive the fifth drive unit and the sixth drive unit to be turned on, the energy storage capacitor is connected in parallel with the second-stage series capacitor so that the energy storage capacitor charges the second-stage series capacitor, thereby achieving energy transfer and voltage equalization from the first-stage series capacitor to the second-stage series capacitor; The second transformer driving module and the first transformer driving module are sequentially turned on based on the second driving signal so that the energy storage capacitor is sequentially connected in parallel with the second-stage series capacitor and the first-stage series capacitor to achieve energy transfer and voltage balancing from the second-stage series capacitor to the first-stage series capacitor, including: The fourth drive unit is turned on based on the third square wave signal to drive the fifth drive unit and the sixth drive unit to be turned on, the energy storage capacitor is connected in parallel with the second-stage series capacitor so that the second-stage series capacitor charges the energy storage capacitor, and then the fifth drive unit and the sixth drive unit are cut off, and the first drive unit is turned on based on the fourth square wave signal to drive the second drive unit and the third drive unit to be turned on, the energy storage capacitor is connected in parallel with the first-stage series capacitor so that the energy storage capacitor charges the first-stage series capacitor, thereby realizing energy transfer and voltage equalization from the second-stage series capacitor to the first-stage series capacitor.

[0008] In the charging module voltage balancing device of the present invention, the first driving unit includes a first switching tube, a second switching tube, a third switching tube, a first driving resistor, a second driving resistor, a third driving resistor and a fourth driving resistor; The third end of the first switching tube is connected to the first signal output end of the microcontroller via the first driving resistor and to the first power supply via the second driving resistor; the first end of the first switching tube is also connected to the first signal output end of the microcontroller, and the second end is connected to the first end of the third driving resistor; the second end of the third driving resistor is connected to the third end of the second switching tube, the third end of the third switching tube and the first end of the fourth driving resistor; the second end of the fourth driving resistor and the second end of the third switching tube are connected to the second power supply, the first end of the third switching tube is connected to the first end of the second switching tube and the same-name end of the primary winding of the first transformer, and the second end of the second switching tube is grounded; the opposite-name end of the primary winding of the first transformer is grounded via a first grounding capacitor.

[0009] In the charging module voltage balancing device of the present invention, the second driving unit includes a fourth switching tube and a fifth driving resistor; the third end of the fourth switching tube is connected to the same-name end of the first secondary winding of the first transformer, the first end of the fourth switching tube is connected to the opposite-name end of the second secondary winding of the first transformer and the first end of the energy storage capacitor, and the second end of the fourth switching tube is connected to the positive electrode of the power supply; the fifth driving resistor is connected between the same-name end and the opposite-name end of the first secondary winding of the first transformer; The third driving unit includes a fifth switching tube and a sixth driving resistor; the third end of the fifth switching tube is connected to the same-name end of the second secondary winding of the first transformer, the first end of the fifth switching tube is connected to the opposite-name end of the second secondary winding of the first transformer and the second end of the energy storage capacitor, and the second end of the fifth switching tube is connected to the connection point of the first-stage series capacitor and the second-stage series capacitor; the sixth driving resistor is connected between the same-name end and the opposite-name end of the second secondary winding of the first transformer.

[0010] In the charging module voltage balancing device of the present invention, the fourth driving unit includes a sixth switching tube, a seventh switching tube, an eighth switching tube, a seventh driving resistor, an eighth driving resistor, a ninth driving resistor, and a tenth driving resistor; The third end of the sixth switching tube is connected to the second signal output end of the microcontroller via the seventh driving resistor and to the first power supply via the eighth driving resistor; the first end of the sixth switching tube is also connected to the first signal output end of the microcontroller, and the second end is connected to the first end of the ninth driving resistor; the second end of the ninth driving resistor is connected to the third end of the seventh switching tube, the third end of the eighth switching tube and the first end of the tenth driving resistor; the second end of the tenth driving resistor and the second end of the eighth switching tube are connected to the second power supply, the first end of the eighth switching tube is connected to the first end of the seventh switching tube and the same-name end of the primary winding of the second transformer, and the second end of the seventh switching tube is grounded; the opposite-name end of the primary winding of the second transformer is grounded via a second grounding capacitor.

[0011] In the charging module voltage balancing device described in the present invention, the fifth driving unit includes a ninth switching tube and an eleventh driving resistor; the third end of the ninth switching tube is connected to the same-name end of the first secondary winding of the second transformer, the first end of the ninth switching tube and the opposite-name end of the second secondary winding of the second transformer are grounded, and the second end of the ninth switching tube is connected to the second end of the energy storage capacitor and the opposite-name end of the second secondary winding of the first transformer; the eleventh driving resistor is connected between the same-name end and the opposite-name end of the first secondary winding of the second transformer; The sixth driving unit includes a tenth switching tube and a twelfth driving resistor; the third end of the tenth switching tube is connected to the same-name end of the second secondary winding of the second transformer, the first end of the tenth switching tube is connected to the opposite-name end of the second secondary winding of the second transformer and the connection point of the first-stage series capacitor and the second-stage series capacitor, and the second end of the tenth switching tube is connected to the first end of the energy storage capacitor; the twelfth driving resistor is connected between the same-name end and the opposite-name end of the second secondary winding of the second transformer.

[0012] In the charging module pressure equalizing device of the present invention, the pressure difference sampling and comparison device includes a first sampling module, a second sampling module, a pressure difference obtaining module and a comparison module; The first end of the first sampling module is connected to the first end of the first-stage series capacitor, the second end is connected to the second end of the first-stage series capacitor, and the third end is connected to the pressure difference obtaining module; The first end of the second sampling module is connected to the first end of the second-stage series capacitor, the second end is connected to the second end of the second-stage series capacitor, and the third end is connected to the voltage difference obtaining module; The output end of the pressure difference obtaining module is connected to the comparison module; The pressure difference sampling and comparison device is used to sample the voltage difference between the first-stage series capacitor and the second-stage series capacitor of the charging module, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the voltage difference and a preset threshold range, including: The first sampling module is used to sample the first voltage value of the first-stage series capacitor of the charging module, the second sampling module is used to sample the second voltage value of the second-stage series capacitor of the charging module, the pressure difference calculation module is used to generate the pressure difference based on the first voltage value and the second voltage value; the comparison module is used to generate the first voltage balancing control signal and the second voltage balancing control signal based on the pressure difference.

[0013] In the charging module voltage balancing device of the present invention, the comparison module includes a first comparator, a second comparator, a comparison reference voltage dividing unit, a first comparison hysteresis setting unit and a second comparison hysteresis setting unit; The comparison reference voltage divider unit is connected between a second power supply and a ground, a first input terminal of the first comparator is connected to a first voltage divider terminal of the comparison reference voltage divider unit, a second input terminal of the first comparator is connected to a first input terminal of the second comparator, a second input terminal of the second comparator is connected to a second voltage divider terminal of the comparison reference voltage divider unit, an output terminal of the first comparator outputs the second voltage-sharing control signal, and an output terminal of the second comparator outputs the first voltage-sharing control signal; The first comparison hysteresis setting unit is connected between the first input terminal and the output terminal of the first comparator, and the second comparison hysteresis setting unit is connected between the first input terminal and the output terminal of the second comparator.

[0014] The charging module voltage equalizing device of the present invention samples the voltage difference between the first series capacitor and the second series capacitor of the charging module through a pressure difference sampling and comparison device, and generates a first voltage equalizing control signal or a second voltage equalizing control signal based on the pressure difference and a preset threshold range, and then generates a first drive signal and a second drive signal based on the first voltage equalizing control signal or the second voltage equalizing control signal through a drive signal generation module. The first transformer drive module and the second transformer drive module are successively turned on based on the first drive signal so that the energy storage capacitor is successively connected in parallel with the first-level series capacitor and the second-level series capacitor to realize energy transfer voltage equalization from the first-level series capacitor to the second-level series capacitor or energy transfer voltage equalization from the second-level series capacitor to the first-level series capacitor. Therefore, there is no need to use the excitation source of the charging module itself, and the two-stage series capacitor voltage equalization of the charging module can be realized in various modes of the charging module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 This is a circuit diagram of a charging module and its voltage equalization circuit in the prior art; Figure 2 This is a principle block diagram of a preferred embodiment of the charging module voltage balancing device of the present invention; Figure 3 This is a principle block diagram of a preferred embodiment of the first transformer driving module of the charging module voltage balancing device of the present invention; Figure 4 This is a principle block diagram of a preferred embodiment of the second transformer driving module of the charging module voltage balancing device of the present invention; Figure 5 This is a principle block diagram of a preferred embodiment of a pressure difference sampling and comparison device for a charging module pressure equalizing device of the present invention; Figure 6 1 is a principle block diagram of a preferred embodiment of a comparison module of a charging module voltage balancing device of the present invention; Figure 7 is a circuit diagram of a preferred embodiment of the charging module voltage equalizing device of the present invention; Figure 8 Shown Figure 7 The first comparator, the second comparator and the control logic of charging and discharging of the series capacitor. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] Figure 2 This is a principle block diagram of a preferred embodiment of the charging module voltage equalizing device of the present invention. Figure 2 As shown, the charging module pressure equalizing device of the present invention includes a pressure difference sampling and comparison device 100 and a pressure equalizing control device 200. The charging module pressure equalizing device of the present invention is suitable for Figure 1 The charging module shown. Figure 2 As shown, the pressure difference sampling and comparison device 100 is used to sample the pressure difference between the series capacitor EC3 and the series capacitor EC4 of the charging module, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the pressure difference and a preset threshold range. The voltage balancing control device 200 is connected to the series capacitor EC3 and the series capacitor EC4 to balance the voltage of the series capacitor EC3 and the series capacitor EC4.

[0018] Here, the pressure difference sampling and comparison device 100 can adopt any known sampling circuit and comparison circuit structure, as long as it can sample the voltage difference between the series capacitor EC3 and the series capacitor EC4, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the pressure difference and a preset threshold range.

[0019] The voltage balancing control device 200 includes a drive signal generation module 210, an energy storage capacitor 240, a first transformer drive module 220, and a second transformer drive module 230. The drive signal generation module 210 generates a first drive signal and a second drive signal based on the first voltage balancing control signal or the second voltage balancing control signal, respectively; the first transformer drive module 220 and the second transformer drive module 230 are sequentially turned on based on the first drive signal, thereby connecting the energy storage capacitor 240 in parallel with the series capacitor EC3 and the series capacitor EC4 in sequence to achieve energy transfer and voltage balancing from the series capacitor EC3 to the series capacitor EC4; or the second transformer drive module 230 and the first transformer drive module 220 are sequentially turned on based on the second drive signal, thereby connecting the energy storage capacitor 240 in parallel with the series capacitor EC4 and the series capacitor EC3 in sequence to achieve energy transfer and voltage balancing from the series capacitor EC4 to the series capacitor EC3.

[0020] Here, the driving signal generation module 210 can be, for example, a microcontroller. The first driving signal includes a complementary first square wave signal and a second square wave signal; the second driving signal includes a complementary third square wave signal and a fourth square wave signal. The microcontroller generates the first square wave signal and the second square wave signal based on the first voltage equalization control signal, sends the first square wave signal to the first transformer driving module 220, and sends the second square wave signal to the second transformer driving module 230; the microcontroller generates the third square wave signal and the fourth square wave signal based on the second voltage equalization control signal, sends the third square wave signal to the first transformer driving module 220, and sends the fourth square wave signal to the second transformer driving module 230.

[0021] In a preferred embodiment of the present invention, in the first half cycle of the first square wave signal, it is at a high level, and in the second half cycle, it is at a low level; in the first half cycle of the second square wave signal, it is at a low level, and in the second half cycle, it is at a high level; in the first half cycle of the third square wave signal, it is at a low level, and in the second half cycle, it is at a high level; in the first half cycle of the fourth square wave signal, it is at a high level, and in the second half cycle, it is at a low level.

[0022] Of course, in other preferred embodiments of the present invention, other settings can also be adopted, as long as it can ensure that the first square wave signal and the second square wave signal are complementary, and the third square wave signal and the fourth square wave signal are complementary. Of course, in other preferred embodiments of the present invention, other driving waveforms can also be adopted, as long as it can drive the first transformer driving module 220 and the second transformer driving module 230 to conduct alternately.

[0023] Of course, in other preferred embodiments of the present invention, the capacitance values of the series capacitor EC4 and the series capacitor EC3 are equal, for example, M, and the capacitance value of the energy storage capacitor 240, for example, N, is less than 1 / 10 of the capacitance values of the series capacitor EC4 and the series capacitor EC3, that is, N < M / 10. For example, N = 0.05M, N = 0.02M, etc.

[0024] The first transformer driving module 220 and the second transformer driving module 230 can select any suitable transformer and the corresponding driving unit structure. Figure 3 It is a principle block diagram of a preferred embodiment of the first transformer driving module of the voltage equalization device of the charging module of the present invention. Figure 4 It is a principle block diagram of a preferred embodiment of the second transformer driving module of the voltage equalization device of the charging module of the present invention.

[0025] The first transformer driving module 220 includes a first transformer 221, a first driving unit 222, a second driving unit 223, and a third driving unit 224. The first driving unit 222 is connected to the primary winding of the first transformer 221, the second driving unit 223 is connected to the first secondary winding of the first transformer 221, and the third driving unit 224 is connected to the second secondary winding of the first transformer 221. The second transformer driving module 230 includes a second transformer 231, a fourth driving unit 232, a fifth driving unit 233, and a sixth driving unit 234. The fourth driving unit 232 is connected to the primary winding of the second transformer 231, the fifth driving unit 233 is connected to the first secondary winding of the second transformer 231, and the sixth driving unit 234 is connected to the second secondary winding of the second transformer 231. The energy storage capacitor 240 has a first end connected to the second driving unit 223 and the sixth driving unit 234, and a second end connected to the third driving unit 224 and the fifth driving unit 233.

[0026] The first driving unit 222 is turned on based on the first square wave signal to drive the second driving unit 223 and the third driving unit 224 to be turned on, the energy storage capacitor 240 is connected in parallel with the series capacitor EC3 so that the series capacitor EC3 charges the energy storage capacitor 240, and then the second driving unit 223 and the third driving unit 224 are turned off, the fourth driving unit 232 is turned on based on the second square wave signal to drive the fifth driving unit 233 and the sixth driving unit 234 to be turned on, the energy storage capacitor 240 is connected in parallel with the series capacitor EC4 so that the energy storage capacitor 240 charges the series capacitor EC4, thereby realizing energy transfer and voltage equalization from the series capacitor EC3 to the series capacitor EC4. The fourth driving unit 232 is turned on based on the third square wave signal to drive the fifth driving unit 233 and the sixth driving unit 234 to be turned on, the energy storage capacitor 240 is connected in parallel with the series capacitor EC4 so that the series capacitor EC4 charges the energy storage capacitor 240, and then the fifth driving unit 233 and the sixth driving unit 234 are cut off, and the first driving unit 222 is turned on based on the fourth square wave signal to drive the second driving unit 223 and the third driving unit 224 to be turned on, the energy storage capacitor 240 is connected in parallel with the series capacitor EC3 so that the energy storage capacitor 240 charges the series capacitor EC3, thereby realizing energy transfer and voltage equalization from the series capacitor EC4 to the series capacitor EC3.

[0027] Figure 5 This is a principle block diagram of a preferred embodiment of the pressure difference sampling and comparison device of the charging module pressure equalizing device of the present invention. Figure 5 As shown, the pressure difference sampling and comparison device 100 includes a first sampling module 110, a second sampling module 120, a pressure difference determination module 130, and a comparison module 140. The first sampling module 110 is used to sample the first voltage value of the series capacitor EC3 of the charging module, and the second sampling module 120 is used to sample the second voltage value of the series capacitor EC4 of the charging module. The pressure difference determination module 130 is used to generate the pressure difference based on the first and second voltage values. The comparison module 140 is used to generate the first and second voltage balancing control signals based on the pressure difference. For example, when the pressure difference indicates that the voltage of the series capacitor EC3 is too high, the first pressure balancing control signal is generated, and when the pressure difference indicates that the voltage of the series capacitor EC4 is too high, the second pressure balancing control signal is generated.

[0028] In a preferred embodiment of the present invention, the first sampling module 110 and the second sampling module 120 can be constructed using any sampling module known in the art. The pressure difference determination module 130 can be constructed using any suitable comparator or operational amplifier. The comparison module 140 can be constructed using, for example, two comparators.

[0029] In a preferred embodiment of the present invention, the first end of the first sampling module 110 is connected to the first end of the series capacitor EC3, the second end is connected to the second end of the series capacitor EC3, and the third end is connected to the pressure difference obtaining module 130; the first end of the second sampling module 120 is connected to the first end of the series capacitor EC4, the second end is connected to the second end of the series capacitor EC4, and the third end is connected to the pressure difference obtaining module 130; the output end of the pressure difference obtaining module 130 is connected to the comparison module 140; the first sampling module 110 is used to sample the first voltage value of the series capacitor EC3 of the charging module, the second sampling module 120 is used to sample the second voltage value of the series capacitor EC4 of the charging module, and the pressure difference obtaining module 130 is used to generate the pressure difference based on the first voltage value and the second voltage value.

[0030] Figure 6 FIG. 1 is a block diagram of a preferred embodiment of a comparison module of a charging module voltage equalization device of the present invention. Figure 6As shown, the comparison module 140 includes a comparator OP4, a comparator OP5, a comparison reference voltage divider unit 141, a first comparison hysteresis setting unit 142, and a second comparison hysteresis setting unit 143. The comparison reference voltage divider unit 141 is connected between a 3.3V power supply and ground. The first input terminal of the comparator OP4 is connected to the first voltage divider terminal of the comparison reference voltage divider unit 141, and the second input terminal is connected to the first input terminal of the comparator OP5. The second input terminal of the comparator OP5 is connected to the second voltage divider terminal of the comparison reference voltage divider unit 141. The output terminal of the comparator OP5 outputs the first voltage-sharing control signal, and the output terminal of the comparator OP4 outputs the second voltage-sharing control signal. The first comparison hysteresis setting unit 142 is connected between the second input terminal and the output terminal of the comparator OP4, and the second comparison hysteresis setting unit 143 is connected between the first input terminal and the output terminal of the comparator OP5. The comparison reference voltage divider unit 141 is configured to generate a first preset threshold value and a second preset threshold value, where the first preset threshold value and the second preset threshold value are the two end values ​​of the preset threshold value range. The comparator OP5 is configured to compare the voltage difference with the first preset threshold value and the second preset threshold value, respectively, and thereby determine whether the voltage of the series capacitor EC3 is too high based on the comparison results. If the voltage of the series capacitor EC3 is determined to be too high, the first voltage balancing control signal is generated. The comparator OP4 is configured to compare the voltage difference with the first preset threshold value and the second preset threshold value, respectively, and thereby determine whether the voltage of the series capacitor EC4 is too high based on the comparison results. If the voltage of the series capacitor EC4 is determined to be too high, the second voltage balancing control signal is generated. The first comparison hysteresis setting unit 142 and the second comparison hysteresis setting unit 143 are configured to set the hysteresis of the comparators OP4 and OP5, respectively.

[0031] The charging module voltage equalizing device of the present invention samples the voltage difference between the first series capacitor and the second series capacitor of the charging module through a pressure difference sampling and comparison device, and generates a first voltage equalizing control signal or a second voltage equalizing control signal based on the pressure difference and a preset threshold range, and then generates a first drive signal and a second drive signal based on the first voltage equalizing control signal or the second voltage equalizing control signal through a drive signal generation module. The first transformer drive module and the second transformer drive module are successively turned on based on the first drive signal so that the energy storage capacitor is successively connected in parallel with the first-level series capacitor and the second-level series capacitor to realize energy transfer voltage equalization from the first-level series capacitor to the second-level series capacitor or energy transfer voltage equalization from the second-level series capacitor to the first-level series capacitor. Therefore, there is no need to use the excitation source of the charging module itself, and the two-stage series capacitor voltage equalization of the charging module can be realized in various modes of the charging module.

[0032] Figure 74 is a circuit diagram of a preferred embodiment of the charging module voltage equalizing device of the present invention. Figure 7 The charging module to which the charging module voltage equalizing device of the present invention is applicable is further shown. The charging module includes an ACDC converter 1 and a DCDC converter 2. The DCDC converter 2 includes a full-bridge switch tube Q11~Q24, a full-bridge switch tube Q1~Q8, a series capacitor EC3, and a series capacitor EC4. The charging module voltage equalizing device of the present invention includes a pressure difference sampling and comparison device 100 and a pressure equalizing control device 200. The pressure difference sampling and comparison device 100 is used to sample the pressure difference between the series capacitor EC3 and the series capacitor EC4 of the charging module, and generate a first pressure equalizing control signal or a second pressure equalizing control signal based on the pressure difference and a preset threshold range. The pressure equalizing control device 200 is connected to the series capacitor EC3 and the series capacitor EC4 for pressure equalizing the series capacitor EC3 and the series capacitor EC4.

[0033] Further integration Figures 2 to 6 As shown, the pressure difference sampling and comparison device 100 includes a first sampling module 110, a second sampling module 120, a pressure difference obtaining module 130 and a comparison module 140. The pressure equalization control device 200 includes a drive signal generating module 210, an energy storage capacitor 240 (i.e. Figure 7 The energy storage capacitor EC5 shown in the figure), the first transformer driving module 220, and the second transformer driving module 230.

[0034] Further Figure 7 As shown, the first sampling module 110 includes an operational amplifier OP1, a sampling resistor R5, a sampling resistor R4, a sampling resistor R6, and a sampling resistor R3; a first input terminal of the operational amplifier OP1 is connected to the first terminal of the series capacitor EC3 via the sampling resistor R5, a second input terminal is connected to the second terminal of the series capacitor EC3 via the sampling resistor R4, and an output terminal is connected to the first input terminal of the voltage difference determination module 130 (the first input terminal of the operational amplifier OP3); the first input terminal of the operational amplifier OP1 is also grounded via the sampling resistor R6, and the second input terminal of the operational amplifier OP1 is also connected to the output terminal of the operational amplifier OP1 via the sampling resistor R3.

[0035] The second sampling module 120 includes an operational amplifier OP2, a sampling resistor R9, a sampling resistor R8, a sampling resistor R10, and a sampling resistor R7. The first input terminal of the operational amplifier OP2 is connected to the first terminal of the series capacitor EC4 via the sampling resistor R9, the second input terminal is connected to the second terminal of the series capacitor EC4 via the sampling resistor R8, and the output terminal is connected to the second input terminal of the voltage difference determination module 130 (the second input terminal of the operational amplifier OP3). The first input terminal of the operational amplifier OP2 is also grounded via the sampling resistor R10, and the second input terminal of the operational amplifier OP2 is also connected to the output terminal of the operational amplifier OP2 via the sampling resistor R7.

[0036] The voltage difference obtaining module 130 includes an operational amplifier OP3, a resistor R11, a resistor R13, a resistor R12, a resistor R14, a resistor R15, a resistor R16, and a capacitor C10; a first input terminal of the operational amplifier OP3 is connected to the output terminal of the operational amplifier OP1 via the resistor R13, a second input terminal is connected to the output terminal of the operational amplifier OP2 via the resistor R12, and the output terminal is connected to the first input terminal of the comparator OP5 and the second input terminal of the comparator OP4 via the resistor R16; the first input terminal of the operational amplifier OP3 is also grounded via the resistor R14 and connected to a power supply 3.3V via the resistor R15, the second input terminal of the operational amplifier OP3 is also connected to the output terminal of the operational amplifier OP3 via the resistor R11, and the first input terminal of the comparator OP5 and the second input terminal of the comparator OP4 are also grounded via the capacitor C10.

[0037] The comparison module 140 includes a comparator OP4, a comparator OP5, a comparison reference voltage divider unit 141, a first comparison hysteresis setting unit 142, and a second comparison hysteresis setting unit 143. The comparison reference voltage divider unit 141 includes comparison reference voltage divider resistors R17, R18, and R19. The first comparison hysteresis setting unit 142 includes a hysteresis setting resistor R20. The second comparison hysteresis setting unit 143 includes hysteresis setting resistors R22, R21, and a hysteresis setting switch Q10.

[0038] The reference voltage divider unit 141 is connected between a 3.3V power supply and ground. The first input of the comparator OP4 is connected to the first voltage divider terminal of the reference voltage divider unit 141 (i.e., the connection point between reference voltage divider resistors R18 and R19), and the second input of the comparator OP4 is connected to the first input of the comparator OP5. The second input of the comparator OP5 is connected to the second voltage divider terminal of the reference voltage divider unit 141 (i.e., the connection point between reference voltage divider resistors R17 and R18). The comparator OP5 is configured to generate the first voltage balancing control signal based on the voltage difference when the voltage of the series capacitor EC3 is relatively high. The comparator OP4 is configured to generate the second voltage balancing control signal when the voltage difference indicates that the voltage of the series capacitor EC4 is relatively high.

[0039] The first end of the first comparison hysteresis setting unit 142 is connected to the first input end of the comparator OP4, and the second end is connected to the output end of the comparator OP4. The first end of the second comparison hysteresis setting unit 143 is connected to the first input end of the comparator OP5, and the second end is connected to the output end of the comparator OP5. The first comparison hysteresis setting unit 142 is used to set the hysteresis of the comparator OP4; the second comparison hysteresis setting unit 143 is used to set the hysteresis of the comparator OP5.

[0040] The first end of the reference voltage divider resistor R17 is connected to the 3.3V power supply, and the second end is connected to the first end of the reference voltage divider resistor R18 and the second input end of the comparator OP5. The second end of the reference voltage divider resistor R18 is connected to the first end of the reference voltage divider resistor R19 and the first input end of the comparator OP4. The second end of the reference voltage divider resistor R19 is grounded. The first input end of the comparator OP5 and the second input end of the comparator OP4 are connected to the pressure difference sampling module 100 (i.e., the connection point between the resistor R16 and the capacitor C10) to receive the pressure difference. The first end of the hysteresis setting resistor R20 is connected to the first input end of the comparator OP4, and the second end is connected to the output end of the comparator OP4. A first end of the hysteresis setting resistor R22 is connected to the output end of the comparator OP5, a second end of the hysteresis setting resistor R22 is connected to the third end of the hysteresis setting switch tube Q10, a first end of the hysteresis setting switch tube Q10 is connected to the second input end of the comparator OP5 via the hysteresis setting resistor R21, and a second end of the hysteresis setting switch tube Q10 is grounded.

[0041] Further Figure 7As shown, the drive signal generation module 210 includes a microcontroller U9. A first input terminal ADC2 of the microcontroller U9 is connected to the output terminal of the comparator OP5 to receive the first voltage-sharing control signal, and a second input terminal ADC1 is connected to the output terminal of the comparator OP4 to receive the second voltage-sharing control signal. The microcontroller U9 generates a first drive signal based on the first voltage-sharing control signal or a second drive signal based on the second voltage-sharing control signal. The first drive signal includes a complementary first square wave signal and a second square wave signal; the second drive signal includes a complementary third square wave signal and a fourth square wave signal. The first output terminal PWM2 of the microcontroller U9 outputs the first square wave signal or the third square wave signal to the first transformer drive module 220, and the second output terminal PWM1 outputs the second square wave signal or the fourth square wave signal to the second transformer drive module 230. There is a dead zone between the first square wave signal and the second square wave signal, and there is a dead zone between the third square wave signal and the fourth square wave signal.

[0042] The first transformer driving module 220 includes a first transformer 221 ( Figure 7 The first drive unit 222 is connected to the primary winding of the first transformer 221, the second drive unit 223 is connected to the first secondary winding of the first transformer 221, and the third drive unit 224 is connected to the second secondary winding of the first transformer 221. The second transformer drive module 230 includes a second transformer 231 ( Figure 7 The first end of the energy storage capacitor 240 is connected to the second drive unit 223 and the sixth drive unit 234, and the second end is connected to the third drive unit 224 and the fifth drive unit 233.

[0043] Further Figure 7 As shown, the first driving unit 222 includes a switch tube Q25, a switch tube Q26, a switch tube Q27, a driving resistor R34, a driving resistor R35, a driving resistor R39 and a driving resistor R25. The second driving unit 223 includes a switch tube Q16 and a driving resistor R28. The third driving unit 224 includes a switch tube Q20 and a driving resistor R40. Figure 7As shown, the third end of the switch tube Q25 is connected to the signal output terminal PWM2 of the microcontroller U9 via the driving resistor R34 and to the 3.3V power supply via the driving resistor R35; the first end of the switch tube Q25 is also connected to the signal output terminal PWM2 of the microcontroller U9, and the second end is connected to the first end of the driving resistor R39; the second end of the driving resistor R39 is connected to the third end of the switch tube Q26, the third end of the switch tube Q27 and the first end of the driving resistor R25; the second end of the driving resistor R25 and the second end of the switch tube Q27 are connected to the 14V power supply, the first end of the switch tube Q27 is connected to the first end of the switch tube Q26 and the same-name end of the primary winding of the transformer T3, and the second end of the switch tube Q26 is grounded; the opposite-name end of the primary winding of the transformer T3 is grounded via the grounding capacitor C8. The third end of the switch Q16 is connected to the same-name terminal of the first secondary winding N1 of the transformer T3, the first end of the switch Q16 is connected to the opposite-name terminal of the first secondary winding N1 of the transformer T3 and the first end of the energy storage capacitor EC5, and the second end of the switch Q16 is connected to the positive electrode of the power supply. The driving resistor R28 is connected between the same-name terminal and the opposite-name terminal of the first secondary winding N1 of the transformer T3. The third end of the switch Q20 is connected to the same-name terminal of the second secondary winding N2 of the transformer T3, the first end of the switch Q20 is connected to the opposite-name terminal of the second secondary winding N2 of the transformer T3 and the second end of the energy storage capacitor EC5, and the second end of the switch Q20 is connected to the connection point of the series capacitor EC3 and the series capacitor EC4, and the first end of the switch Q17. The driving resistor R40 is connected between the same-name terminal and the opposite-name terminal of the second secondary winding N2 of the transformer T3.

[0044] The fourth driving unit 232 includes a switch tube Q15, a switch tube Q18, a switch tube Q19, a driving resistor R32, a driving resistor R33, a driving resistor R37 and a driving resistor R24. The fifth driving unit 233 includes a switch tube Q9 and a driving resistor R31. The sixth driving unit 234 includes a switch tube Q17 and a driving resistor R41. Figure 7As shown, the third end of the switch tube Q15 is connected to the signal output terminal PWM1 of the microcontroller U9 via the driving resistor R32 and to the 3.3V power supply via the driving resistor R33; the first end of the switch tube Q15 is also connected to the signal output terminal PWM2 of the microcontroller U9, and the second end is connected to the first end of the driving resistor R37; the second end of the driving resistor R37 is connected to the third end of the switch tube Q18, the third end of the switch tube Q19 and the first end of the driving resistor R24; the second end of the driving resistor R24 ​​and the second end of the switch tube Q19 are connected to the 14V power supply, the first end of the switch tube Q19 is connected to the first end of the switch tube Q18 and the same-name end of the primary winding of the transformer T4, and the second end of the switch tube Q18 is grounded; the opposite-name end of the primary winding of the transformer T4 is grounded via the grounding capacitor C14. The third end of the switch tube Q9 is connected to the same-name end of the first secondary winding N1 of the transformer T4, the first end of the switch tube Q9 and the opposite-name end of the first secondary winding N1 of the transformer T4 are grounded, and the second end of the switch tube Q9 is connected to the second end of the energy storage capacitor EC5; the driving resistor R31 is connected between the same-name end and the opposite-name end of the first secondary winding N1 of the transformer T4; the third end of the switch tube Q17 is connected to the same-name end of the second secondary winding N2 of the transformer T4, the first end of the switch tube Q17 is connected to the opposite-name end of the second secondary winding N2 of the transformer T4 and the connection point of the series capacitor EC3 and the series capacitor EC4, and the second end of the switch tube Q17 is connected to the first end of the switch tube Q16 and the opposite-name end of the first secondary winding N1 of the transformer T3; the driving resistor R41 is connected to the first end of the energy storage capacitor EC5.

[0045] In a preferred embodiment of the present invention, when the switch transistors Q15 and Q25 are MOS transistors or IGBT transistors, their third terminal is the gate, their first terminal is the drain, and their second terminal is the source. When they are triodes, their third terminal is the base, their first terminal is the collector, and their second terminal is the emitter. In this preferred embodiment, the switch transistors Q15 and Q25 are driven using source or emitter drive, that is, their control terminal is the second terminal. When they are MOS transistors or IGBT transistors, the control terminal is the source, and when they are triodes, the control terminal is the emitter. Of course, in other preferred embodiments of the present invention, gate / gate / base drive can also be used instead. Those skilled in the art can adjust the circuit and control logic of the present invention according to actual needs to implement the technical solution of the present invention, and will not be repeated here. Other switching transistors of the present invention, such as switching transistors Q10, Q18-Q19, Q26-Q27, Q16-Q17, Q9, and Q20, may also be MOS transistors, IGBT transistors, or triodes, all of which are gate / gate / base driven. When they are MOS transistors or IGBT transistors, their control terminal is the gate or gate, their first terminal is the drain, and their second terminal is the source; when they are triodes, their control terminal is the base, their first terminal is the collector, and their second terminal is the emitter.

[0046] Figure 8 Shown Figure 7 The control logic of the comparator OP5, comparator OP4 and the charging and discharging of the series capacitors EC3 and EC4. Figures 7 and 8 The principles of the present invention are described in detail as follows. Operational amplifiers OP1 and OP2 are respectively used to differentially amplify (i.e., attenuate) the upper and lower bus voltages connected to series capacitors EC3 and EC4, and then output a first voltage value of series capacitor EC3 and a second voltage value of series capacitor EC4, respectively, referenced to a common ground GND. Operational amplifier OP3 then differentially amplifies the first and second voltage values ​​of series capacitor EC3 and EC4, calculating the voltage difference between them. This voltage difference is generated based on the first and second voltage values. Simultaneously, a DC bias is applied to operational amplifier OP3, causing the voltage difference between series capacitors EC3 and EC4 to vary within this bias. This variation reflects the degree of voltage difference between series capacitors EC3 and EC4, i.e., the voltage difference between the two series capacitors EC3 and EC4. Furthermore, comparators OP4 and OP5 are provided with a hysteresis setting unit, which ensures that the output levels of comparators OP4 and OP5 remain within a certain range, preventing level fluctuations.

[0047] When the voltage of the series capacitor EC3 is high, the voltage difference is input into the comparison module composed of comparators OP4 and OP5. After receiving the voltage difference signal from the operational amplifier OP3, the comparator OP5 determines whether the voltage of the series capacitor EC3 is high. If so, it generates the first voltage-equalizing control signal, for example, a high-level signal. This high-level signal (first voltage-equalizing control signal) is input into the first input terminal ADC2 of the microcontroller U9. The first input terminal ADC2 of the microcontroller U9 is connected to the output terminal of the comparator OP5 to receive the first voltage-equalizing control signal and generates a first drive signal based on the first voltage-equalizing control signal. The first drive signal includes a complementary first square wave signal and a second square wave signal. The first output terminal PWM2 of the microcontroller U9 outputs the first square wave signal to the first transformer driver module 220, and the second output terminal PWM1 outputs the second square wave signal to the second transformer driver module 230. Preferably, a dead zone exists between the first square wave signal and the second square wave signal. The first square wave signal is high in the first half of its cycle and low in the second half. The second square wave signal is low in the first half of its cycle and high in the second half. Therefore, the first output terminal PWM2 of the microcontroller U9 first outputs the high-level first square wave signal, and the second output terminal PWM1 first outputs the low-level second square wave signal. The high-level first square wave signal drives the primary winding of transformer T3 through the switches Q25, Q26, and Q27 of the first drive unit 222. The two secondary windings N1 and N2 of transformer T3 drive the switches Q16 and Q20 of the second drive unit 223 and the third drive unit 224, respectively, in isolation. After the switches Q16 and Q20 are turned on, the energy storage capacitor EC5 is connected in parallel with the series capacitor EC3. Thus, the series capacitor EC3 charges the energy storage capacitor EC5, and some energy is transferred from the series capacitor EC3 to the energy storage capacitor EC5. After half a PWM cycle, the first square wave signal and the second square wave signal are reversed. At this time, the first square wave signal is at a low level, and the second square wave signal is at a high level.Therefore, the first output terminal PWM2 of the microcontroller U9 outputs a low-level first square wave signal, and the second output terminal PWM1 outputs a high-level second square wave signal. Therefore, the switch tubes Q25, Q26, and Q27 of the primary winding of the transformer T3 are turned off, and then the secondary windings N1 and N2 of the transformer T3 stop driving the switch tubes Q16 and Q20, and the switch tubes Q16 and Q20 are turned off. Similarly, the high-level second square wave signal passes through the switch tubes Q15, Q18, and Q19 of the fourth driving unit 232. The primary winding of the driving transformer T4 and the two secondary windings N1 and N2 of the transformer T4 are isolated and driven to turn on the switch tubes Q9 and Q17 of the fifth driving unit 233 and the sixth driving unit 234 respectively. After the switch tubes Q9 and Q17 are turned on, the energy storage capacitor EC5 is connected in parallel with the series capacitor EC4. The energy storage capacitor EC5, which was charged by the series capacitor EC3 in the first half cycle, charges the series capacitor EC4 in parallel, thereby realizing the transfer of energy from the series capacitor EC3 to the series capacitor EC4.

[0048] Similarly, when the voltage of the series capacitor EC4 is high, the voltage difference is input into the comparison module formed by comparators OP4 and OP5. After receiving the voltage difference signal from the operational amplifier OP3, comparator OP4 determines whether the voltage of the series capacitor EC4 is high. If so, it generates a second voltage-sharing control signal, for example, a high-level signal. This high-level signal (second voltage-sharing control signal) is input into the second input terminal ADC1 of the microcontroller U9. The second input terminal ADC1 of the microcontroller U9 is connected to the output terminal of the comparator OP4 to receive the second voltage-sharing control signal and generates a second drive signal based on the second voltage-sharing control signal. The second drive signal includes a complementary third-wave signal and a fourth square-wave signal. The first output terminal PWM2 of the microcontroller U9 outputs the third-wave signal to the first transformer driver module 220, and the second output terminal PWM1 outputs the fourth square-wave signal to the second transformer driver module 230. Preferably, a dead zone exists between the third-wave signal and the fourth square-wave signal. The third square wave signal is low in the first half of its cycle and high in the second half. The fourth square wave signal is high in the first half of its cycle and low in the second half. Therefore, the first output terminal PWM2 of the microcontroller U9 first outputs the low-level third square wave signal, and the second output terminal PWM1 first outputs the high-level fourth square wave signal. The high-level fourth square wave signal drives the primary winding of transformer T4 through the switches Q15, Q18, and Q19 of the fourth drive unit 232. The two secondary windings N1 and N2 of transformer T4, respectively, drive the switches Q9 and Q17 of the fifth drive unit 233 and the sixth drive unit 234 to conduct. After the switches Q9 and Q17 are turned on, the energy storage capacitor EC5 is connected in parallel with the series capacitor EC4. Thus, the series capacitor EC4 charges the energy storage capacitor EC5, and some energy is transferred from the series capacitor EC4 to the energy storage capacitor EC5. After half a PWM cycle, the third and fourth square wave signals flip, with the third square wave signal at a high level and the fourth square wave signal at a low level. Therefore, the first output terminal PWM2 of the microcontroller U9 outputs a high-level third square wave signal, while the second output terminal PWM1 outputs a low-level fourth square wave signal.Such a high-level third wave signal drives the primary winding of the transformer T3 through the switching tubes Q25, Q26, and Q27 of the first driving unit 222. The two secondary windings N1 and N2 of the transformer T3 respectively drive the switching tubes Q16 and Q20 of the second driving unit 223 and the third driving unit 224 in isolation. After the switching tubes Q16 and Q20 are turned on, the energy storage capacitor EC5 is connected in parallel with the series capacitor EC3. The energy storage capacitor EC5, which was charged by the series capacitor EC4 in the first half cycle, charges the series capacitor EC3 in parallel, thereby realizing energy transfer from the series capacitor EC4 to the series capacitor EC3.

[0049] It should be noted that after energy storage capacitor EC5 is connected in parallel with series capacitor EC3 or series capacitor EC4, energy storage capacitor EC5 will be charged to the same voltage as series capacitor EC3 or series capacitor EC4. Similarly, after the charged energy storage capacitor EC5 is connected in parallel with series capacitor EC3 or series capacitor EC4, part of the energy of energy storage capacitor EC5 is injected into series capacitor EC3 or series capacitor EC4. The value of energy storage capacitor EC5 is less than 1 / 10 of the value of series capacitor EC3 or series capacitor EC4. Thus, after energy storage capacitor EC5 is connected in parallel with series capacitor EC3 or series capacitor EC4, the voltage change of series capacitor EC3 or series capacitor EC4 can be ignored.

[0050] The charging module voltage balancing device of the present invention samples the voltage difference between the first and second series capacitors of the charging module via a voltage difference sampling and comparison device, and generates a first voltage balancing control signal or a second voltage balancing control signal based on the voltage difference and a preset threshold range. A drive signal generation module then generates a first drive signal and a second drive signal based on the first voltage balancing control signal or the second voltage balancing control signal. The first transformer drive module and the second transformer drive module are sequentially turned on based on the first drive signal, thereby connecting the energy storage capacitor in parallel with the first and second series capacitors, respectively, to achieve energy transfer voltage balancing from the first series capacitor to the second series capacitor, or from the second series capacitor to the first series capacitor. Therefore, there is no need to use the charging module's own excitation source, and voltage balancing of the two series capacitors of the charging module can be achieved in various modes of the charging module. Furthermore, by driving the corresponding half-bridge switch tube drive unit via an isolation transformer to form an excitation source and initiate energy transfer, energy transfer efficiency can be improved, thereby improving circuit efficiency.

[0051] Although the present invention is described by way of specific embodiments, it will be understood by those skilled in the art that various modifications and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. Furthermore, various modifications may be made to the present invention for specific circumstances or materials without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but is intended to encompass all embodiments falling within the scope of the claims.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A charging module voltage equalizing device, characterized in that: include: a pressure difference sampling and comparison device, configured to sample the pressure difference between the first-stage series capacitor and the second-stage series capacitor of the charging module, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the pressure difference and a preset threshold range; as well as A voltage balancing control device, comprising a drive signal generating module, an energy storage capacitor, a first transformer driving module, and a second transformer driving module; The driving signal generating module generates a first driving signal and a second driving signal based on the first voltage balancing control signal or the second voltage balancing control signal respectively; The first transformer driving module and the second transformer driving module are turned on successively based on the first driving signal so that the energy storage capacitor is connected in parallel with the first-level series capacitor and the second-level series capacitor in turn to achieve energy transfer and voltage balancing from the first-level series capacitor to the second-level series capacitor; or the second transformer driving module and the first transformer driving module are turned on successively based on the second driving signal so that the energy storage capacitor is connected in parallel with the second-level series capacitor and the first-level series capacitor in turn to achieve energy transfer and voltage balancing from the second-level series capacitor to the first-level series capacitor.

2. The charging module voltage equalizing device according to claim 1, characterized in that: The driving signal generating module includes a microcontroller; the first driving signal includes a first square wave signal and a second square wave signal that are complementary; the second driving signal includes a third square wave signal and a fourth square wave signal that are complementary; The driving signal generating module generates a first driving signal and a second driving signal based on the first voltage balancing control signal or the second voltage balancing control signal, respectively, including: The microcontroller generates the first square wave signal and the second square wave signal based on the first voltage-sharing control signal, and sends the first square wave signal to the first transformer driving module and sends the second square wave signal to the second transformer driving module; The microcontroller generates the third square wave signal and the fourth square wave signal based on the second voltage-sharing control signal, and sends the third square wave signal to the first transformer driving module and sends the fourth square wave signal to the second transformer driving module.

3. The charging module voltage equalizing device according to claim 2, characterized in that: The first square wave signal is at a high level in the first half of its cycle and at a low level in the second half of its cycle; the second square wave signal is at a low level in the first half of its cycle and at a high level in the second half of its cycle; The third square wave signal is at a low level in the first half of its cycle and at a high level in the second half of its cycle. The fourth square wave signal is at a high level in the first half of its cycle and at a low level in the second half of its cycle.

4. The charging module voltage equalizing device according to claim 2, characterized in that: The capacitance values ​​of the first-stage series capacitor and the second-stage series capacitor are equal, and the capacitance value of the energy storage capacitor is less than one tenth of the capacitance value of the first-stage series capacitor or the second-stage series capacitor.

5. The charging module voltage balancing device according to any one of claims 2 to 4, characterized in that: The first transformer driving module includes a first transformer, a first driving unit, a second driving unit, and a third driving unit; the first driving unit is connected to one side of the primary winding of the first transformer, the second driving unit is connected to one side of the first secondary winding of the first transformer, and the third driving unit is connected to one side of the second secondary winding of the first transformer; The second transformer driving module includes a second transformer, a fourth driving unit, a fifth driving unit and a sixth driving unit; the fourth driving unit is connected to one side of the primary winding of the second transformer, the fifth driving unit is connected to one side of the first secondary winding of the second transformer, and the sixth driving unit is connected to one side of the second secondary winding of the second transformer; A first end of the energy storage capacitor is connected to the second drive unit and the sixth drive unit, and a second end is connected to the third drive unit and the fifth drive unit; The first transformer driving module and the second transformer driving module are sequentially turned on based on the first driving signal so that the energy storage capacitor is sequentially connected in parallel with the first-stage series capacitor and the second-stage series capacitor to achieve energy transfer and voltage balancing from the first-stage series capacitor to the second-stage series capacitor, including: The first drive unit is turned on based on the first square wave signal to drive the second drive unit and the third drive unit to be turned on, the energy storage capacitor is connected in parallel with the first-stage series capacitor so that the first-stage series capacitor charges the energy storage capacitor, and then the second drive unit and the third drive unit are turned off, the fourth drive unit is turned on based on the second square wave signal to drive the fifth drive unit and the sixth drive unit to be turned on, the energy storage capacitor is connected in parallel with the second-stage series capacitor so that the energy storage capacitor charges the second-stage series capacitor, thereby achieving energy transfer and voltage equalization from the first-stage series capacitor to the second-stage series capacitor; The second transformer driving module and the first transformer driving module are sequentially turned on based on the second driving signal so that the energy storage capacitor is sequentially connected in parallel with the second-stage series capacitor and the first-stage series capacitor to achieve energy transfer and voltage balancing from the second-stage series capacitor to the first-stage series capacitor, including: The fourth drive unit is turned on based on the third square wave signal to drive the fifth drive unit and the sixth drive unit to be turned on, the energy storage capacitor is connected in parallel with the second-stage series capacitor so that the second-stage series capacitor charges the energy storage capacitor, and then the fifth drive unit and the sixth drive unit are cut off, and the first drive unit is turned on based on the fourth square wave signal to drive the second drive unit and the third drive unit to be turned on, the energy storage capacitor is connected in parallel with the first-stage series capacitor so that the energy storage capacitor charges the first-stage series capacitor, thereby realizing energy transfer and voltage equalization from the second-stage series capacitor to the first-stage series capacitor.

6. The charging module voltage equalizing device according to claim 5, characterized in that: The first driving unit includes a first switching tube, a second switching tube, a third switching tube, a first driving resistor, a second driving resistor, a third driving resistor and a fourth driving resistor; The third end of the first switching tube is connected to the first signal output end of the microcontroller via the first driving resistor and to the first power supply via the second driving resistor; the first end of the first switching tube is also connected to the first signal output end of the microcontroller, and the second end is connected to the first end of the third driving resistor; the second end of the third driving resistor is connected to the third end of the second switching tube, the third end of the third switching tube and the first end of the fourth driving resistor; the second end of the fourth driving resistor and the second end of the third switching tube are connected to the second power supply, the first end of the third switching tube is connected to the first end of the second switching tube and the same-name end of the primary winding of the first transformer, and the second end of the second switching tube is grounded; the opposite-name end of the primary winding of the first transformer is grounded via a first grounding capacitor.

7. The charging module voltage equalizing device according to claim 5, characterized in that: The second driving unit includes a fourth switching tube and a fifth driving resistor; the third end of the fourth switching tube is connected to the same-name end of the first secondary winding of the first transformer, the first end of the fourth switching tube is connected to the opposite-name end of the second secondary winding of the first transformer and the first end of the energy storage capacitor, and the second end of the fourth switching tube is connected to the positive electrode of the power supply; the fifth driving resistor is connected between the same-name end and the opposite-name end of the first secondary winding of the first transformer; The third driving unit includes a fifth switching tube and a sixth driving resistor; the third end of the fifth switching tube is connected to the same-name end of the second secondary winding of the first transformer, the first end of the fifth switching tube is connected to the opposite-name end of the second secondary winding of the first transformer and the second end of the energy storage capacitor, and the second end of the fifth switching tube is connected to the connection point of the first-stage series capacitor and the second-stage series capacitor; the sixth driving resistor is connected between the same-name end and the opposite-name end of the second secondary winding of the first transformer.

8. The charging module voltage equalizing device according to claim 5, characterized in that: The fourth driving unit includes a sixth switching tube, a seventh switching tube, an eighth switching tube, a seventh driving resistor, an eighth driving resistor, a ninth driving resistor and a tenth driving resistor; The third end of the sixth switching tube is connected to the second signal output end of the microcontroller via the seventh driving resistor and to the first power supply via the eighth driving resistor; the first end of the sixth switching tube is also connected to the first signal output end of the microcontroller, and the second end is connected to the first end of the ninth driving resistor; the second end of the ninth driving resistor is connected to the third end of the seventh switching tube, the third end of the eighth switching tube and the first end of the tenth driving resistor; the second end of the tenth driving resistor and the second end of the eighth switching tube are connected to the second power supply, the first end of the eighth switching tube is connected to the first end of the seventh switching tube and the same-name end of the primary winding of the second transformer, and the second end of the seventh switching tube is grounded; the opposite-name end of the primary winding of the second transformer is grounded via a second grounding capacitor.

9. The charging module voltage equalizing device according to claim 5, characterized in that: The fifth driving unit includes a ninth switching tube and an eleventh driving resistor; the third end of the ninth switching tube is connected to the same-name end of the first secondary winding of the second transformer, the first end of the ninth switching tube and the opposite-name end of the second secondary winding of the second transformer are grounded, and the second end of the ninth switching tube is connected to the second end of the energy storage capacitor and the opposite-name end of the second secondary winding of the first transformer; the eleventh driving resistor is connected between the same-name end and the opposite-name end of the first secondary winding of the second transformer; The sixth driving unit includes a tenth switching tube and a twelfth driving resistor; the third end of the tenth switching tube is connected to the same-name end of the second secondary winding of the second transformer, the first end of the tenth switching tube is connected to the opposite-name end of the second secondary winding of the second transformer and the connection point of the first-stage series capacitor and the second-stage series capacitor, and the second end of the tenth switching tube is connected to the first end of the energy storage capacitor; the twelfth driving resistor is connected between the same-name end and the opposite-name end of the second secondary winding of the second transformer.

10. The charging module voltage equalizing device according to claim 5, characterized in that: The pressure difference sampling and comparison device includes a first sampling module, a second sampling module, a pressure difference obtaining module and a comparison module; The first end of the first sampling module is connected to the first end of the first-stage series capacitor, the second end is connected to the second end of the first-stage series capacitor, and the third end is connected to the pressure difference obtaining module; The first end of the second sampling module is connected to the first end of the second-stage series capacitor, the second end is connected to the second end of the second-stage series capacitor, and the third end is connected to the voltage difference obtaining module; The output end of the pressure difference obtaining module is connected to the comparison module; The pressure difference sampling and comparison device is used to sample the voltage difference between the first-stage series capacitor and the second-stage series capacitor of the charging module, and generate a first voltage balancing control signal or a second voltage balancing control signal based on the voltage difference and a preset threshold range, including: The first sampling module is used to sample the first voltage value of the first-stage series capacitor of the charging module, the second sampling module is used to sample the second voltage value of the second-stage series capacitor of the charging module, the pressure difference calculation module is used to generate the pressure difference based on the first voltage value and the second voltage value; the comparison module is used to generate the first voltage balancing control signal and the second voltage balancing control signal based on the pressure difference.

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