Low-loss conversion circuit and energy storage system

Abstract

The invention relates to a low-loss conversion circuit and an energy storage system. Comprising a step-down module connected with a power supply, a bypass module connected with the step-down module in parallel, an adjusting module and a control module, the adjusting module is used for detecting the input voltage of the power supply; the dynamic regulation module outputs a dynamic regulation signal to a feedback pin of the control module based on the input voltage, and outputs a first control signal to the bypass module when the input voltage is greater than or equal to the reference voltage; when the input voltage is smaller than the reference voltage, a second control signal is output to the bypass module; the bypass module is used for working under the action of the second control signal so as to bypass the voltage reduction module; and stop working under the action of the first control signal. The control module is used for adjusting the duty ratio of the first driving signal output to the step-down module to be within a preset range based on the dynamic adjusting signal; and the voltage reduction module is used for performing voltage reduction processing on the input voltage based on the first driving signal and then outputting power supply voltage. The method can improve the utilization rate of battery power.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage power supplies, and in particular to a low-loss conversion circuit and an energy storage system. Background Art

[0002] Currently, for energy storage power supplies with a wide input voltage range, such as an input voltage range between 24V and 43V, in order to meet the requirements of DC output function control modules such as USB-C (Universal Serial Bus - Type C), USB-A (Universal Serial Bus - Type A), and cigarette lighters with a maximum voltage of 40V, a buck circuit (step-down switching regulator circuit) is added between the battery and these DC output functions. The output voltage of this buck circuit is fixed, such as 22V.

[0003] However, in this buck circuit, when the input voltage is high (such as 43V), the current passing through the first diode generates large losses. When the input voltage is low (24-29V), although it is theoretically possible to directly supply power from the battery to avoid the buck circuit's voltage drop losses, the traditional operating method cannot avoid this unnecessary loss. As a result, the energy storage power supply has large or unnecessary losses in the buck circuit, reducing battery power utilization. Summary of the Invention

[0004] Based on this, it is necessary to provide a low-loss conversion circuit and energy storage system to address the above technical problems.

[0005] In a first aspect, the present application provides a low-loss conversion circuit, comprising:

[0006] A step-down module connected to a power supply, a bypass module connected in parallel with the step-down module, a regulating module, and a control module;

[0007] The regulating module is configured to detect an input voltage of the power supply; output a dynamic regulating signal to a feedback pin of the control module based on the input voltage; and output a first control signal to the bypass module when the input voltage is greater than or equal to a reference voltage; and output a second control signal to the bypass module when the input voltage is less than the reference voltage;

[0008] The bypass module is configured to operate under the action of the second control signal to bypass the step-down module; and stop operating under the action of the first control signal;

[0009] The control module is configured to adjust the duty cycle of the first driving signal output to the buck module based on the dynamic adjustment signal to be within a preset range;

[0010] The buck module is configured to step down the input voltage based on the first driving signal and then output a supply voltage.

[0011] In one embodiment, the bypass module includes: a switch unit and a driver;

[0012] A first end of the switch unit is connected to a power supply, a second end of the switch unit is connected to the circuit output end, and a control end of the switch unit is connected to an output end of the driver;

[0013] The driver, an input end of the driver is connected to the adjustment module, and an output end of the driver is connected to the control end of the switch unit;

[0014] The switch unit is configured to be turned on under the action of the second control signal and turned off under the action of the first control signal.

[0015] In one embodiment, the adjustment module is further configured to output a first enable signal to an enable end of the control module when the input voltage is greater than or equal to a reference voltage, so that the control module adjusts the duty cycle of the first driving signal output to the buck module based on the dynamic adjustment signal to be within a preset range; when the input voltage is less than the reference voltage, output a second enable signal to the enable end of the control module, so that the control module stops working.

[0016] In one embodiment, the adjustment module includes:

[0017] A voltage sampling unit configured to sample the input voltage;

[0018] A comparison unit configured to output the second control signal when the input voltage is less than the reference voltage and output the first control signal when the input voltage is greater than or equal to the reference voltage;

[0019] A feedback adjustment unit configured to output the dynamic adjustment signal to a feedback pin of the control module based on the input voltage.

[0020] In one embodiment, the voltage sampling unit includes: a fifth resistor, a seventh resistor, and a voltage follower;

[0021] A first end of the fifth resistor is connected to a power supply, a second end of the fifth resistor is connected to a first end of the seventh resistor and a non-inverting input end of the voltage follower, a second end of the seventh resistor is grounded, and an inverting input end of the voltage follower is connected to an output end of the voltage follower.

[0022] In one embodiment, the second control signal is a high-level signal, the first control signal is a low-level signal, and the comparison unit includes:

[0023] A comparator, the inverting input terminal of the comparator is connected to the voltage sampling unit, the non-inverting input terminal of the comparator is connected to a reference power supply, the output terminal of the comparator is connected to the bypass module, and the comparator is configured to output the high-level signal when the input voltage is less than the reference voltage, and output the low-level signal when the input voltage is greater than or equal to the reference voltage.

[0024] In one embodiment, the feedback adjustment unit includes: an enable control sub-unit and an adjustable voltage divider unit. The input terminal of the enable control sub-unit is connected to the output terminal of the comparison unit, and the input terminal of the adjustable voltage divider unit is connected to the voltage sampling unit;

[0025] The enable control sub-unit is configured to output a first enable signal to the enable pin of the control module under the action of the first control signal, and output a second enable signal to the enable pin of the control module under the action of the second control signal;

[0026] The adjustable resistance value corresponding to the adjustable voltage divider unit decreases as the input voltage increases. The adjustable voltage divider unit is configured to divide the input voltage through the adjustable resistance value to obtain the dynamic adjustment signal.

[0027] In one embodiment, the adjustable voltage divider unit includes: a triode, the base of the triode is connected to the voltage sampling unit, and the emitter of the triode is grounded;

[0028] The triode is configured to operate in the amplification region when the input voltage is greater than or equal to the reference voltage, and the equivalent resistance between the collector and the emitter of the triode decreases as the input voltage increases.

[0029] In one embodiment, the adjustable voltage divider unit further includes:

[0030] A sixth resistor, a first resistor, a second resistor, and a third resistor;

[0031] The base of the triode is connected to the voltage sampling unit through the sixth resistor, the collector of the triode is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the first resistor, the first end of the third resistor, and the feedback pin of the control module, the second end of the third resistor is grounded, and the second end of the first resistor is connected to the circuit output terminal.

[0032] In one embodiment, the control module is configured to adjust the duty cycle of the first driving signal output to the buck module to be within the preset range when the voltage of the dynamic adjustment signal is less than a preset value.

[0033] In a second aspect, the present application further provides an energy storage system, which includes the low-loss conversion circuit as described in the first aspect, and the circuit output end of the low-loss conversion circuit is connected to multiple DC output interfaces of the energy storage system.

[0034] The above-mentioned low-loss conversion circuit and energy storage system include: a buck module connected to a power supply, a bypass module connected in parallel with the buck module, an adjustment module, and a control module; the adjustment module is configured to detect the input voltage of the power supply; output a dynamic adjustment signal to the feedback pin of the control module based on the input voltage, and when the input voltage is greater than or equal to a reference voltage, output a first control signal to the bypass module; when the input voltage is less than the reference voltage, output a second control signal to the bypass module; the bypass module is configured to operate under the action of the second control signal to bypass the buck module; and stop operating under the action of the first control signal; the control module is configured to adjust the duty cycle of the first driving signal output to the buck module to be within a preset range based on the dynamic adjustment signal; the buck module is configured to step down the input voltage based on the first driving signal and then output a supply voltage. Through this solution, when the input voltage is less than the reference voltage, the adjustment module controls the bypass module to operate, directly bypassing the buck module, so that the battery energy can be directly output without passing through the BUCK circuit step-down, avoiding unnecessary losses of the BUCK circuit under low input voltage in the traditional solution; and when the input voltage is greater than or equal to the reference voltage, the bypass module stops operating, and the control module can adjust the duty cycle of the first driving signal output to the buck module to be within the preset range based on the dynamic adjustment driving signal, so that the buck module can efficiently step down the input voltage to the target value under the action of this first driving signal. Compared with the situation of large losses caused by a fixed duty cycle in the traditional solution, the energy loss under high input voltage is significantly reduced by dynamically optimizing the duty cycle. In addition, the mechanism of the adjustment module detecting the input voltage in real time and feeding back the dynamic adjustment signal ensures that the buck module always operates in an efficient range, further improving the energy conversion efficiency of the entire system within a wide input voltage range, effectively improving the battery power utilization rate, and avoiding the technical defect of coexistence of high losses and unnecessary losses. Description of the Drawings

[0035] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the accompanying drawings required for the description of the embodiments or related technologies. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0036] Figure 1 It is a schematic circuit diagram of a BUCK circuit for bucking in related technologies;

[0037] Figure 2 It is a schematic diagram of a low-loss conversion circuit in an embodiment Figure 1 ;

[0038] Figure 3 It is a schematic diagram of the bypass module 22 and the buck module 21 in the low-loss conversion circuit in an embodiment;

[0039] Figure 4 It is a schematic diagram of a low-loss conversion circuit in an embodiment Figure 2 ;

[0040] Figure 5 It is a schematic diagram of the control module 24 and the adjustment module 23 in the low-loss conversion circuit in an embodiment. Detailed implementation manners

[0041] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further details the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] In an energy storage power supply with a relatively wide battery voltage range (24V - 43V), for cost considerations, control chips with a maximum withstand voltage of 40V are selected for its DC output functions such as USB-C, USB-A, and cigarette lighter. To meet the withstand voltage requirements of the control chip, a stage of BUCK circuit needs to be added between the battery output terminal and these DC output function modules to adjust the output voltage to below 40V.

[0043] Exemplarily, Figure 1 It is a schematic circuit diagram of a BUCK circuit for bucking in related technologies. As Figure 1As shown, the BUCK circuit includes: a driver, a first MOS (Metal - Oxide - Semiconductor Field - Effect Transistor) transistor Q1, a first diode D1, a first inductor LD1, a capacitor C1, and a capacitor C2. It can be seen that the BUCK circuit is connected between the power supply (i.e., the battery) and the output voltage terminal. Usually, the supply voltage Vout output by the BUCK circuit is a fixed value (such as 22V). At different battery voltages BAT+, there will be varying degrees of loss in the power conversion efficiency. When the battery voltage BAT+ is relatively high (such as 43V), the duty cycle of the BUCK circuit is approximately 51%. This means that within 49% of the cycle time, the current will flow through the first diode D1. Especially when the DC output functions such as the rear - end USB - C, USB - A, and cigarette lighter are in full - load working conditions, the current on the first diode D1 is relatively large, resulting in a large loss.

[0044] When the battery voltage BAT+ is relatively low (such as 24 - 29V), the duty cycle will exceed 75%, that is, only less than 25% of the cycle time does the current pass through the first diode D1. Taking the battery voltage of 24V as an example, the duty cycle is as high as 91.7% at this time, meaning that 8.3% of the cycle time the current will flow through the first diode D1. In fact, within the voltage range of 24V - 29V, the battery voltage BAT+ already meets the withstand voltage requirements of the control chip. It is completely possible to directly supply power to the DC output function circuits such as the rear - end USB - C, USB - A, and cigarette lighter by constantly conducting the first MOS transistor Q1, without the need to step down the voltage through the BUCK circuit, thus avoiding the loss generated by the first diode D1. However, the traditional working mode cannot achieve this optimization, resulting in this part of the loss being unavoidable.

[0045] In summary, the traditional working method causes significant or unnecessary losses in part of the battery voltage range of the energy storage power supply in the BUCK circuit, reducing the battery power utilization rate and weakening the market competitiveness of the product.

[0046] The embodiment of the present application provides a low - loss conversion circuit and an energy storage system, which improve the energy conversion efficiency of the entire system within a wide input voltage range, effectively improve the battery power utilization rate, and avoid the problem of co - existence of the above - mentioned high losses and unnecessary losses.

[0047] In an exemplary embodiment, as Figure 2 shown, a schematic diagram of the low - loss conversion circuit in an embodiment is provided Figure 1 , and this circuit includes:

[0048] A buck module 21 connected to a power supply, a bypass module 22 connected in parallel with the buck module 21, an adjustment module 23, and a control module 24; wherein, the power supply can be a battery, and the battery can output a battery voltage BAT+.

[0049] The adjustment module 23 is configured to detect the input voltage of the power supply; output a dynamic adjustment signal to the feedback pin FB of the control module 24 based on the input voltage, and output a first control signal to the bypass module 22 when the input voltage is greater than or equal to a reference voltage; and output a second control signal to the bypass module 22 when the input voltage is less than the reference voltage.

[0050] The bypass module 22 is configured to operate under the action of the second control signal to bypass the buck module 21; and stop operating under the action of the first control signal.

[0051] The control module 24 is configured to adjust the duty cycle of the first driving signal output to the buck module 21 to be within a preset range based on the dynamic adjustment signal.

[0052] The buck module 21 is configured to step down the input voltage based on the first driving signal and then output a supply voltage Vout.

[0053] Wherein, the duty cycle being within the preset range means that the duty cycle is 81.4% ± 5%. The above Figure 2 GND therein represents the ground terminal.

[0054] In some embodiments, the above reference voltage can be 30V. The above input voltage being greater than or equal to the reference voltage can mean that BAT+ is in the range of 30V - 43V, and the above input voltage being less than the reference voltage means that BAT+ is less than 30V.

[0055] In some embodiments, the above control module 24 can be a control chip (Control IC).

[0056] In some embodiments, the above first control signal can be a low-level signal, and the second control signal can be a high-level signal. That is to say, Figure 2 in the circuit, the adjustment module 23 can output a first control signal to the bypass module 22 when the input voltage is greater than or equal to the reference voltage to control the bypass module 22 not to operate, and output a dynamic adjustment signal to the feedback pin FB of the control module 24 based on the input voltage, so that the control module 24 adjusts the duty cycle of the first driving signal output to the buck module 21 to be within a preset range based on the dynamic adjustment signal, so that the buck module 21 can output a corresponding supply voltage Vout under the action of the first driving signal; when the input voltage is less than the reference voltage, output a second control signal to the bypass module 22 to control the bypass module 22 to operate and bypass the buck module 21.

[0057] Among them, the above dynamic adjustment signal can be an analog voltage signal that is positively correlated with the change in the input voltage or a Pulse Width Modulation (PWM) signal.

[0058] When the input voltage is less than the reference voltage (such as 30V), there is still a certain distance between the input voltage and the withstand voltage value (such as 40V) of the control module 24. At this time, direct power supply will not exceed the withstand voltage value, and there is no need to let the buck module 21 consume power. Therefore, a second control signal is output to the bypass module 22 to control the bypass module 22 to work, bypassing the buck module 21, which can avoid the power consumption of the buck module 21.

[0059] When the input voltage is greater than or equal to the reference voltage (such as 30V), the voltage approaches the critical value of the 40V withstand voltage value (such as 40V). At this time, bucking is required. At this time, a first control signal is output to the bypass module 22 to control the bypass module 22 not to work, but to let the buck module 21 work. And at this time, the buck module 21 is synchronously bucked under the action of a first drive signal with a duty cycle within a preset range, so that the energy loss at high input voltages can be significantly reduced by dynamically optimizing the duty cycle.

[0060] In the above embodiment, when the input voltage is less than the reference voltage, the adjustment module controls the bypass module to work, directly bypassing the buck module, so that the battery energy can be directly output without passing through the BUCK circuit for bucking, avoiding the unnecessary loss of the BUCK circuit at low input voltages in the traditional scheme; when the input voltage is greater than or equal to the reference voltage, the bypass module stops working, and the control module can adjust the duty cycle of the first drive signal output to the buck module to be within a preset range based on the dynamic adjustment drive signal. In this way, the buck module can efficiently buck the input voltage to the target value under the action of this first drive signal. Compared with the situation of large losses caused by a fixed duty cycle in the traditional scheme, the energy loss at high input voltages is significantly reduced by dynamically optimizing the duty cycle. In addition, the mechanism of the adjustment module for real-time detecting the input voltage and feedbacking the dynamic adjustment signal ensures that the buck module always works in an efficient range, further improving the energy conversion efficiency of the entire system within a wide input voltage range, effectively improving the battery power utilization rate, and avoiding the technical defect of coexistence of high losses and unnecessary losses.

[0061] In some embodiments, such as Figure 2As shown, when the input voltage is greater than or equal to the reference voltage, the above-mentioned adjustment module 23 is further configured to output a first enable signal to the enable terminal EN (also referred to as the enable pin) of the control module 24, so that the control module 24 adjusts the duty cycle of the first drive signal output to the buck module 21 based on the dynamic adjustment signal to be within a preset range; when the input voltage is less than the reference voltage, a second enable signal is output to the enable terminal EN of the control module 24, so that the control module 24 stops working.

[0062] In the above embodiment, when the input voltage is greater than or equal to the reference voltage, the adjustment module sends a first enable signal to the enable terminal of the control module to wake up the control module to work. At this time, the control module optimizes the duty cycle of the drive signal in real time based on the dynamic adjustment signal (such as 81.4% ± 5%), enabling the buck module to efficiently step down the voltage in the high voltage section and avoiding the large current loss of the freewheeling diode under the traditional fixed duty cycle; when the input voltage is less than the reference voltage, the adjustment module outputs a second enable signal to force the control module to stop working and cut off its own power consumption. Cooperating with the conduction of the bypass module to bypass the buck module, double energy saving is achieved, avoiding both the conversion loss of the buck circuit and the no-load power consumption of the control module, and further reducing unnecessary losses compared to the mode where the control module continuously operates in the traditional solution. This mechanism keeps the system in a state of high efficiency during operation and dormancy during idleness within a wide voltage range, reducing energy loss and significantly improving the battery power utilization rate.

[0063] In an exemplary embodiment, on the basis of Figure 2 as Figure 3 shown, a schematic diagram of the bypass module 22 and the buck module 21 in the low-loss conversion circuit in an embodiment is provided.

[0064] As Figure 3 shown, the bypass module 22 includes: a switch unit 221 and a second driver 222; a first end of the switch unit 221 is connected to the power supply, a second end of the switch unit 221 is connected to the circuit output end, and the circuit output end can output a supply voltage Vout. A control end of the switch unit 221 is connected to an output end of the second driver 222; an input end of the second driver 222 is connected to Figure 2 the adjustment module 23 in

[0065] wherein, the above-mentioned switch unit 221 can specifically be a second MOS transistor Q2. A first end of the second MOS transistor Q2 (i.e., Figure 3 the 3-pin of Q2 in Figure 3 is connected to the power supply, a second end of the second MOS transistor Q2 (i.e.,Figure 3 The 1-pin of Q2 in the figure is connected to the output terminal of the second driver 222. Figure 3 Drv2 in the figure is the driving signal input to the second driver 222.

[0066] Exemplarily, as Figure 3 shown, the buck module 21 includes: a first driver 211, a third MOS transistor Q3, a second diode D2, a second inductor LD2, a third capacitor C3, and a fourth capacitor C4. Figure 3 Drv1 in the figure is the driving signal input to the first driver 211.

[0067] Based on the above Figure 3 shown circuit, in the bypass module 22, when the input voltage (such as the battery voltage BAT+) is less than the reference voltage (such as 30V), the adjustment module 23 outputs a second control signal (high-level signal) to the second driver 222 to drive Q2 to conduct. At this time, the power supply is directly connected to the circuit output terminal, and the buck module 21 is bypassed to avoid power consumption; when the input voltage is greater than or equal to the reference voltage, the adjustment module 23 outputs a first control signal (low-level signal) to control Q2 to turn off, the bypass module 22 stops working, and the buck module 21 operates.

[0068] Based on the above Figure 3 shown circuit, Drv1 is input to the first driver 211 to adjust the switching duty cycle of Q3 (preset 81.4% ± 5%). When Drv1 is at a high level, Q3 conducts, and the power supply charges LD2 through Q3, and LD2 stores energy; when Drv1 is at a low level, Q3 turns off, and the inductor continues to supply power to the load through D2, and at the same time, C3 and C4 filter to stabilize the output supply voltage Vout. Figure 2 The control module 24 in the figure optimizes the duty cycle in real time based on the signal fed back by the adjustment module 23 to ensure efficient bucking at high input voltages and reduce energy loss.

[0069] In an exemplary embodiment, on the basis of Figure 2 as Figure 4 shown, it is a schematic diagram of a low-loss conversion circuit in an embodiment. Figure 2 As Figure 4 shown, the adjustment module 23 includes: a voltage sampling unit 231 for collecting the input voltage; a comparison unit 232 for outputting a second control signal when the input voltage is less than the reference voltage and outputting a first control signal when the input voltage is greater than or equal to the reference voltage; a feedback adjustment unit 233 for outputting a dynamic adjustment signal to the feedback pin FB of the control module 24 based on the input voltage.

[0070] In an exemplary embodiment, on the basis of Figure 4Based on, such as Figure 5 shown, is a schematic diagram of the control module 24 and the adjustment module 23 in the low-loss conversion circuit in an embodiment.

[0071] Exemplarily, such as Figure 5 shown, the control module 24 is Figure 5 the control chip (Control IC) in

[0072] Exemplarily, such as Figure 5 shown, Figure 4 the voltage sampling unit 231 in the adjustment module 23 in Figure 5 can include: the fifth resistor R5, the seventh resistor R7, and the voltage follower U1A; the first end of the fifth resistor R5 is connected to the power supply, and the second end of the fifth resistor is connected to the first end of the seventh resistor R7 and the non-inverting input terminal of the voltage follower U1A (i.e., Figure 5 [[ID=2O]]the 5th pin of U1A in Figure 5 ), the second end of the seventh resistor R7 is grounded, and the inverting input terminal of the voltage follower U1A (i.e.,

[0073] Exemplarily, such as Figure 5 shown, the second control signal is a high-level signal, the first control signal is a low-level signal, and the comparison unit 232 in the adjustment module 23 includes: a comparator U2A, the inverting input terminal of the comparator UZA (i.e., Figure 5 the 4th pin of U2A in Figure 5 is connected to the voltage sampling unit 231, the non-inverting input terminal of the comparator U2A (i.e., Figure 5 the 5th pin of U2A in

[0074] Exemplarily, such as Figure 5 shown, the feedback adjustment unit 233 in the adjustment module 23 includes: an enable control subunit and an adjustable voltage dividing unit, the input terminal of the enable control subunit is connected to the output terminal of the comparison unit U2A, and the input terminal of the adjustable voltage dividing unit is connected to the voltage sampling unit 231; wherein, the enable control subunit is used to output a first enable signal to the enable pin EN of the control module 24 under the action of the first control signal, and output a second enable signal to the enable pin EN of the control module 24 under the action of the second control signal.

[0075] Exemplarily, such as Figure 5As shown, the above-mentioned enabling control subunit includes: the fifth MOS transistor Q5. The control terminal of the fifth MOS transistor Q5 is the input terminal of the enabling control subunit. The first terminal of the fifth MOS transistor Q5 is connected to the enabling pin EN of the control chip, and the second terminal of the fifth MOS transistor Q5 is grounded.

[0076] Among them, the adjustable resistance value corresponding to the adjustable voltage dividing unit decreases as the input voltage increases. The adjustable voltage dividing unit is used to divide the input voltage through the adjustable resistance value to obtain a dynamically adjustable signal.

[0077] Exemplarily, as Figure 5 shown, the adjustable voltage dividing unit includes: a triode Q4. The base of the triode Q4 is connected to the voltage sampling unit 231, and the emitter of the triode Q4 is grounded, that is, connected to the ground terminal GND.

[0078] Among them, the triode Q4 is used to operate in the amplification region when the input voltage is greater than or equal to the reference voltage. The equivalent resistance between the collector and the emitter of the triode Q4 decreases as the input voltage increases.

[0079] In some embodiments, the adjustable voltage dividing unit further includes: a sixth resistor R6, a first resistor R1, a second resistor R2, and a third resistor R3. The base of the triode Q4 is connected to the voltage sampling unit 231 through the sixth resistor R6. The collector of the triode Q4 is connected to the first terminal of the second resistor R2. The second terminal of the second resistor R2 is connected to the first terminal of the first resistor R1, the first terminal of the third resistor R3, and the feedback pin FB of the control module 24. The second terminal of the third resistor R3 is grounded, and the second terminal of the first resistor R1 is connected to the circuit output terminal.

[0080] The above-mentioned feedback regulation unit 233 optimizes the working efficiency of the buck module 21 through a dynamic voltage dividing mechanism, and significantly reduces the energy loss in a wide input voltage range. The adjustable voltage dividing characteristic of this unit enables it to adjust the feedback signal of the control module 24 in real time according to the input voltage. Among them, when the input voltage increases, the equivalent resistance of the triode Q4 decreases, and the voltage dividing ratio decreases, forcing the control module 24 to increase the duty cycle of the first driving signal to ensure that the buck module 21 can still efficiently convert energy in the high voltage section; when the input voltage decreases, the equivalent resistance increases, the voltage dividing ratio increases, and the duty cycle of the first driving signal decreases accordingly, avoiding the loss caused by excessive bucking. This dynamic regulation mechanism enables the buck module 21 to always work in the optimal duty cycle range, effectively reducing the freewheeling loss of the traditional fixed duty cycle design at high voltage input.

[0081] In addition, the above-mentioned feedback adjustment unit 233 and comparison unit 232 work together to achieve intelligent start-stop control of the control module 24. When the input voltage is lower than the reference voltage, the comparison unit 232 outputs a high-level signal to enable the control sub-unit to cut off the power supply of the control module 24. At the same time, the bypass module 22 conducts, completely eliminating the static power consumption of the buck module 21 and the control module 24. When the input voltage is higher than the reference voltage, the control module 24 is awakened and precisely adjusts the duty cycle of the first driving signal based on the dynamic voltage division signal. This dual energy-saving strategy not only avoids the conversion loss during the buck process but also eliminates the no-load power consumption of the control module 24, improving the energy efficiency of the circuit to the optimal state within the full voltage range.

[0082] It should be noted that, as Figure 5 shown, the above circuit also includes: the third diode D3, resistors R9, R11, R8, R10, R4, etc. Figure 5 The VCC and Vcc1 shown in

[0083] Exemplarily, taking the above Figure 5 shown circuit as an example, the resistance value of the sixth resistor R6 needs to be set so that when the input voltage is in the range of 30V - 43V, the triode Q4 operates in the amplification region. When the triode Q4 operates in the amplification region, the relationship between the currents of its base and collector is Ic = β * Ib.

[0084] Among them, β is the amplification factor of the triode Q4, Ic is the collector current, and Ib is the base current.

[0085] The resistance value of the above-mentioned second resistor R2 needs to be set so that when the input voltage is 43V, the maximum output supply voltage is 35V, and when the input voltage is in the range of 30V - 43V, the duty cycle of the first driving signal is controlled at about 81.4%. Among them, the duty cycle of the first driving signal of 81.4% can be understood as the theoretical calculated value. The specific output duty cycle in the actual circuit will fluctuate within a certain range of 81.4% and can be determined according to the actual circuit. The 81.4% in the embodiments of the present application is only an example value shown to clearly illustrate the solution.

[0086] In the embodiments of the present application, the relationship formula between the duty cycle of the first driving signal and the input voltage BAT+ and the output supply voltage Vout can be expressed as: D = Vout / BAT+. The relationship between the duty cycle and the input voltage BAT+ and the output supply voltage Vout is shown in Table 1.

[0087] Table 1

[0088]

[0089] In some embodiments, the control module 24 is configured to adjust the duty cycle of the first driving signal (i.e., Drv1) output to the step-down module 21 in Figure 4 to a preset range when the voltage of the dynamic adjustment signal is less than a preset value. Figure 4 In some embodiments, the above preset value can be set according to actual requirements, and the embodiments of the present application do not make any limitations.

[0090] In some embodiments, the above preset value can be set according to actual needs, and the embodiments of the present application do not make any limitations.

[0091] In the above Figure 5 shown circuit, its working principle is as follows:

[0092] When BAT+ is in the range of 30V - 43V, after being divided by R5 and R7, BAT+ enters the non-inverting input terminal of U1A (i.e., pin 5 of U1A). The output terminal of U1A (i.e., pin 2 of U1A) follows the voltage value VBAT+ of the non-inverting input terminal. At this time, since the voltage value of VBAT+ is greater than the voltage value of the reference voltage Vref, the comparator U2A outputs a low-level signal at pin 2, that is, Drv2 is a low-level signal. At this time, the low-level signal makes Figure 3 in Q2 turn off, and at this time Q5 also turns off, and will not pull down the enable pin EN of the control chip (Control IC), and the control chip remains working.

[0093] Meanwhile, the voltage value VBAT+ output from the output terminal of U1A (i.e., pin 2 of U1A) passes through the third triode D3 and R6, and then enters Q4, making Q4 work in the amplification region. At this time, R3 is in parallel with R2 and Q4 and then divides the voltage of Vout with R1. After voltage division, it enters the feedback pin FB of the control chip, so as to adjust the duty cycle of Drv1 to about 81.4% based on BAT+, so that the corresponding relationship between different BAT+ and the voltage of Vout is shown in Table 1.

[0094] Among them, when Q4 works in the amplification region, the larger the current, the smaller the resistance, showing a proportional relationship. For example, when BAT+ is large, the internal resistance of Q4 is smaller, and the resistance value of R3 in parallel with R2 and the triode Q4 is smaller, that is, the voltage ratio of the feedback pin FB is smaller. Since the feedback value is fixed, when the voltage value detected by the feedback pin FB is less than the preset value, the control chip will adjust the duty cycle of Drv1 to increase the output supply voltage Vout. In this way, when the battery voltage is in the range of 30V - 43V, 81.4% of the cycle time is Figure 3 in Q3 conducting, and 18.6% of the cycle time is Figure 3 in D2 for freewheeling operation. In this way, under the same working conditions, since Figure 3 the freewheeling operation time of D2 in is greatly reduced, thereby reducing the loss on this stage of the circuit. Although the conduction time of Q3 increases, since Figure 3 the on-resistance of Q3 in is small, the loss is still very small.

[0095] Exemplarily, for 2 mΩ, if the current is 10 A and the conduction time increases by 30.4%, the power loss increases by 0.06 W. For Figure 3 D2 in [description], if the conduction voltage drop is 0.7 V and the freewheeling time decreases by 30.4%, the power loss decreases by 2.128 W. Therefore, for the 10 A current condition in the above example, the total power loss is reduced by 2.068 W.

[0096] It should be noted that the higher the battery voltage BAT+, the larger VBAT+ is, the larger the current Ib entering the base of Q4 is, and the larger the collector current Ic is. Therefore, the value of the voltage divided by R3 in parallel with R2 and Q4 and then with R1 for Vout entering the feedback pin FB of the control chip is smaller. Due to the internal control principle of the control chip, after adjusting the duty cycle of Drv1, the output supply voltage Vout is also higher.

[0097] When BAT+ is less than 30 V, after being divided by R5 and R7, BAT+ enters the non-inverting input terminal of U1A (i.e., pin 5 of U1A). The output terminal of U1A (i.e., pin 2 of U1A) follows the output voltage value VBAT+ of the non-inverting input terminal of U1A. At this time, since VBAT+ is less than the reference voltage Vref, the comparator U2A outputs a high level at pin 2, that is, Drv2 is a high-level signal. At this time, this high-level signal controls Figure 3 Q2 in [description] to conduct. At this time, Q5 also conducts, pulling down the enable pin EN of the control chip, and the control chip stops working, that is, the BUCK circuit stops working.

[0098] In the above example, BAT+ is directly powered through Figure 3 Q2 in [description], avoiding the power loss generated when the current passes through the freewheeling diode during low battery voltage operation, and also avoiding the power loss generated on the inductor. Similarly, although the conduction time of the MOS tube is increased, due to the reduction of the power loss on the freewheeling diode and the inductor, the overall total power loss is also reduced.

[0099] In summary, within the full range of the battery voltage BAT+ from 24 V to 43 V, by applying the circuit in the embodiment of the present application, at different battery voltages, especially when the backend is fully loaded, the power loss is generally reduced to varying degrees, thereby increasing the battery power utilization rate of the energy storage power supply.

[0100] The circuit provided by the embodiment of the present application can not only make the duty cycle fixed at about 81.4% and work in a low-loss state when the battery voltage is high, but also avoid the power loss generated on the freewheeling diode and the power loss generated on the inductor when the battery voltage is low.

[0101] In some embodiments, the embodiments of the present application further provide an energy storage system, which includes a low-loss conversion circuit as described in any of the above embodiments, and the circuit output end of the low-loss conversion circuit is connected to a plurality of DC output interfaces of the energy storage system.

[0102] Among them, the above DC output interfaces may include, but are not limited to: USB-C, USB-A, cigarette lighter, etc.

[0103] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0104] The above-described embodiments merely represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A low-loss conversion circuit, characterized in that Comprising: A buck module connected to a power supply, a bypass module connected in parallel with the buck module, a regulation module, and a control module; The regulation module is configured to detect the input voltage of the power supply; output a dynamic regulation signal to the feedback pin of the control module based on the input voltage, and output a first control signal to the bypass module when the input voltage is greater than or equal to a reference voltage; and output a second control signal to the bypass module when the input voltage is less than the reference voltage; The bypass module is configured to operate under the action of the second control signal to bypass the buck module; and stop operating under the action of the first control signal; The control module is configured to regulate the duty cycle of the first driving signal output to the buck module to be within a preset range based on the dynamic regulation signal; The buck module is configured to step down the input voltage based on the first driving signal and output a supply voltage.

2. The low-loss conversion circuit according to claim 1, wherein The bypass module includes: a switch unit and a driver; A first end of the switch unit is connected to the power supply, a second end of the switch unit is connected to the circuit output end, and a control end of the switch unit is connected to an output end of the driver; The driver, an input end of the driver is connected to the regulation module, and an output end of the driver is connected to the control end of the switch unit; The switch unit is configured to conduct under the action of the second control signal and turn off under the action of the first control signal.

3. The low-loss conversion circuit according to claim 1 or 2, characterized in that, The regulation module is further configured to output a first enable signal to the enable end of the control module when the input voltage is greater than or equal to the reference voltage, so that the control module regulates the duty cycle of the first driving signal output to the buck module to be within a preset range based on the dynamic regulation signal; and output a second enable signal to the enable end of the control module when the input voltage is less than the reference voltage, so that the control module stops operating.

4. The low-loss conversion circuit according to claim 1, wherein The regulation module includes: A voltage sampling unit configured to collect the input voltage; A comparison unit configured to output the second control signal when the input voltage is less than the reference voltage and output the first control signal when the input voltage is greater than or equal to the reference voltage; A feedback regulation unit configured to output the dynamic regulation signal to the feedback pin of the control module based on the input voltage.

5. The low-loss conversion circuit according to claim 4, wherein, The voltage sampling unit includes: a fifth resistor, a seventh resistor, and a voltage follower; A first end of the fifth resistor is connected to the power supply, a second end of the fifth resistor is connected to a first end of the seventh resistor and the non-inverting input terminal of the voltage follower, a second end of the seventh resistor is grounded, and the inverting input terminal of the voltage follower is connected to the output terminal of the voltage follower.

6. The low-loss conversion circuit according to claim 4, wherein The second control signal is a high-level signal, the first control signal is a low-level signal, and the comparison unit includes: Comparator, an inverting input terminal of the comparator is connected to the voltage sampling unit, a non-inverting input terminal of the comparator is connected to a reference power supply, and an output terminal of the comparator is connected to the bypass module. The comparator is configured to output the high-level signal when the input voltage is less than the reference voltage, and output the low-level signal when the input voltage is greater than or equal to the reference voltage.

7. The low-loss conversion circuit according to claim 4, wherein The feedback adjustment unit includes: an enable control sub-unit and an adjustable voltage division unit. An input terminal of the enable control sub-unit is connected to an output terminal of the comparison unit, and an input terminal of the adjustable voltage division unit is connected to the voltage sampling unit; The enable control sub-unit is configured to output a first enable signal to an enable pin of the control module under the action of the first control signal, and output a second enable signal to the enable pin of the control module under the action of the second control signal; The adjustable resistance value corresponding to the adjustable voltage division unit decreases as the input voltage increases. The adjustable voltage division unit is configured to divide the input voltage through the adjustable resistance value to obtain the dynamic adjustment signal.

8. The low-loss conversion circuit according to claim 7, characterized in that, The adjustable voltage division unit includes: a triode, a base of the triode is connected to the voltage sampling unit, and an emitter of the triode is grounded; The triode is configured to operate in the amplification region when the input voltage is greater than or equal to the reference voltage, and an equivalent resistance between a collector and an emitter of the triode decreases as the input voltage increases.

9. The low-loss conversion circuit according to claim 7 or 8, wherein The control module is configured to adjust a duty cycle of a first driving signal output to the buck module to be within the preset range when a voltage of the dynamic adjustment signal is less than a preset value.

10. A energy storage system, characterized in that, The energy storage system includes the low-loss conversion circuit according to any one of claims 1 to 9, and a circuit output terminal of the low-loss conversion circuit is connected to a plurality of DC output interfaces of the energy storage system.

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