Resonant transformation module, soft start method thereof, control unit and energy storage system

Abstract

The invention provides a resonant conversion module and a soft start method thereof, a control unit and an energy storage system, and the soft start method comprises the steps: dividing a plurality of primary side duty ratio adjustment stages, and setting the duty ratio step length of each primary side duty ratio adjustment stage; according to the duty ratio step length and the duty ratio preset accumulation duration of each primary side duty ratio adjustment stage, soft start of the duty ratio of each adjustment stage is completed until the duty ratio of a primary side switch tube reaches a primary side soft start target duty ratio; a plurality of secondary side duty ratio adjusting stages are divided, and the duty ratio step length of each secondary side duty ratio adjusting stage is set; and according to the duty ratio step length and the duty ratio preset accumulation duration of each secondary side duty ratio adjustment stage, completing the soft start of the duty ratio of each adjustment stage until the duty ratio of a secondary side switch tube reaches a secondary side soft start target duty ratio. By setting the duty ratio step length in stages, the soft start time consumption is reduced, the soft start efficiency is improved, and the working safety of the energy storage system is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of energy storage, in particular to a resonant conversion module, a soft start method thereof, a control unit and an energy storage system. BACKGROUND

[0002] In the soft start process of a conventional resonant converter, the duty cycle is usually adjusted with a fixed step. However, this fixed step soft start method has obvious defects. If the step is set small, although the risk of overcurrent can be avoided, the soft start process will be too long, affecting the starting efficiency of the system. Conversely, if the step is set large, although the starting time can be shortened, the inductance current of the resonant network may rapidly increase due to the sudden change of the duty cycle in the initial stage of soft start, exceeding its peak limit, thereby causing an overcurrent problem. The overcurrent not only may damage the inductance element, but also may affect the reliability and service life of the entire converter. Therefore, how to optimize the soft start strategy of the duty cycle of the resonant converter so as to improve the starting efficiency and avoid the risk of overcurrent has become a technical problem to be solved in the field. SUMMARY

[0003] Embodiments of the present application provide a resonant conversion module, a soft start method thereof, a control unit and an energy storage system, which can improve the soft start efficiency and the safety of the operation of the energy storage system.

[0004] In a first aspect, the embodiments of the present application provide a soft start method of a resonant conversion module. The resonant conversion module includes a primary side switch tube group and a secondary side switch tube group. The primary side switch tube group includes four primary side switch tubes. The secondary side switch tube group includes four secondary side switch tubes. The soft start method includes: dividing a range from a primary side initial duty cycle to a primary side soft start target duty cycle into a plurality of primary side duty cycle adjustment stages, and obtaining a stage target duty cycle of each primary side duty cycle adjustment stage; setting a duty cycle step of each primary side duty cycle adjustment stage according to a maximum resonant current peak value of the resonant conversion module, a voltage effective value of a low voltage bus side set for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage; completing soft start of the duty cycle of each adjustment stage according to the duty cycle step of each primary side duty cycle adjustment stage and a duty cycle preset cumulative time length, until the duty cycle of the primary side switch tube reaches the primary side soft start target duty cycle; dividing a range from a secondary side initial duty cycle to a secondary side soft start target duty cycle into a plurality of secondary side duty cycle adjustment stages, and obtaining a stage target duty cycle of each secondary side duty cycle adjustment stage; setting a duty cycle step of each secondary side duty cycle adjustment stage according to the maximum resonant current peak value of the resonant conversion module, a voltage effective value of a high voltage bus side set for soft start, and the stage target duty cycle of each secondary side duty cycle adjustment stage; and completing soft start of the duty cycle of each adjustment stage according to the duty cycle step of each secondary side duty cycle adjustment stage and the duty cycle preset cumulative time length, until the duty cycle of the secondary side switch tube reaches the secondary side soft start target duty cycle.

[0005] In one or more embodiments, dividing a range from a primary side initial duty cycle to a primary side soft start target duty cycle into a plurality of primary side duty cycle adjustment stages includes: setting a first primary side duty cycle adjustment stage as a quarter of the primary side soft start target duty cycle from the primary side initial duty cycle; setting a second primary side duty cycle adjustment stage as a quarter of the primary side soft start target duty cycle from a half of the primary side soft start target duty cycle; setting a third primary side duty cycle adjustment stage as a half of the primary side soft start target duty cycle from a first preset duty cycle value, wherein the first preset duty cycle value is a difference between the primary side soft start target duty cycle and a first preset threshold, the first preset threshold is greater than 0, and the first preset threshold is less than a half of the primary side soft start target duty cycle; and setting a fourth primary side duty cycle adjustment stage as the first preset duty cycle value to the primary side soft start target duty cycle.

[0006] In one or more embodiments, setting a duty cycle step of each primary side duty cycle adjustment stage according to a maximum resonant current peak value of the resonant conversion module, a voltage effective value of a low voltage bus side set for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage includes: setting the duty cycle step of the first primary side duty cycle adjustment stage as a first preset value, wherein the first preset value is a difference between the maximum resonant current peak value and a second preset threshold, the second preset threshold is greater than 0, and the second preset threshold is less than a half of the maximum resonant current peak value; setting the duty cycle step of the second primary side duty cycle adjustment stage as a second preset value, wherein the second preset value is a difference between the maximum resonant current peak value and a third preset threshold, the third preset threshold is greater than 0, and the third preset threshold is less than a half of the maximum resonant current peak value; setting the duty cycle step of the third primary side duty cycle adjustment stage as a third preset value, wherein the third preset value is a difference between the maximum resonant current peak value and a fourth preset threshold, the fourth preset threshold is greater than 0, and the fourth preset threshold is less than a half of the maximum resonant current peak value; and setting the duty cycle step of the fourth primary side duty cycle adjustment stage as a fourth preset value, wherein the fourth preset value is a difference between the maximum resonant current peak value and a fifth preset threshold, the fifth preset threshold is greater than 0, and the fifth preset threshold is less than a half of the maximum resonant current peak value. satisfies the following relationship:​ ; ; ; wherein, is a peak value of a conduction current of a primary side switch tube in a first primary side duty cycle adjustment phase, is a resonant inductance of a resonant cavity of the resonant conversion module, is a resonant cavity impedance of the resonant conversion module, is a voltage effective value of a low voltage bus side for soft start, is a phase target duty cycle of a first primary side duty cycle adjustment phase, is a voltage value across the resonant inductance of the resonant cavity at the start of the first primary side duty cycle adjustment phase. In one or more embodiments, a value of the duty cycle step of the first primary side duty cycle adjustment phase is greater than a value of the duty cycle step of the second primary side duty cycle adjustment phase.

[0007] In one or more embodiments, a range from the initial secondary side duty cycle to the soft start target secondary side duty cycle is divided into a plurality of secondary side duty cycle adjustment phases, including: setting a quarter of the initial secondary side duty cycle to the soft start target secondary side duty cycle as a first secondary side duty cycle adjustment phase; setting a quarter of the soft start target secondary side duty cycle to a half of the soft start target secondary side duty cycle as a second secondary side duty cycle adjustment phase; setting a half of the soft start target secondary side duty cycle to a second preset duty cycle value as a third secondary side duty cycle adjustment phase, wherein the second preset duty cycle value is a difference between the soft start target secondary side duty cycle and a second preset threshold value, the second preset threshold value is greater than 0, and the second preset threshold value is less than a half of the soft start target secondary side duty cycle; and setting the second preset duty cycle value to the soft start target secondary side duty cycle as a fourth secondary side duty cycle adjustment phase. In one or more embodiments, according to the maximum resonant current peak value of the resonant conversion module, a voltage effective value of a high voltage bus side for soft start, and the phase target duty cycle of each secondary side duty cycle adjustment phase, the duty cycle step of each secondary side duty cycle adjustment phase is set, including: the duty cycle step of the first secondary side duty cycle adjustment phase

[0008] satisfies the following relationship:

[0009] ; ; ; ; ; ​​​wherein, is the peak value of the conduction current of the secondary side switch tube in the first is the target duty cycle of the first is the resonant cavity impedance of the resonant conversion module, is the set voltage effective value of the low-voltage bus side for soft start, is the peak value of the conduction current of the secondary side switch tube in the first is the target duty cycle of the first is the voltage value across the resonant inductance of the resonant cavity at the beginning of the first is the voltage value across the resonant inductance of the resonant cavity at the beginning of the first

[0010] In one or more embodiments, the value step length of the duty cycle of the first is greater than the value of the duty cycle step length of the first is greater than the value of the duty cycle step length of the first

[0011] In a second aspect, the embodiments of the present application provide a control unit, comprising: at least one processor and a memory; the memory is connected with the processor, and the memory is used to store instructions or programs, when the instructions or programs are executed by the control unit, the control unit executes the soft start method as any one of the first aspect.

[0012] In a third aspect, the embodiments of the present application provide a resonant conversion module, comprising: a primary side switch tube group, a secondary side switch tube group, a transformer, a resonant unit and a control unit as the second aspect. The primary side switch tube group is connected with the primary side of the transformer, the secondary side of the transformer is connected with the first end of the resonant unit, the second end of the resonant unit is connected with the secondary side switch tube group, and the control unit is connected with the primary side switch tube group and the secondary side switch tube group.

[0013] In a fourth aspect, the embodiments of the present application provide an energy storage system, comprising: a DCDC module, an inverter module and a resonant conversion module as the third aspect; the resonant conversion module comprises a primary side switch tube group and a secondary side switch tube group, the primary side switch tube group is connected with the DCDC module, and the secondary side switch tube group is connected with the inverter module.

[0014] The beneficial effects of the present application are: the present application provides a resonant conversion module and a soft start method thereof, a control unit and an energy storage system, by dynamically adjusting the duty cycle step length of the primary side switch tube group and the secondary side switch tube group in stages, the duty cycle step length is designed differently in each primary side duty cycle adjustment stage and secondary side duty cycle adjustment stage, the soft start time is reduced, the soft start efficiency is improved, and by comprehensively considering multiple parameters to set the step length, the situation that the inductance current in the resonant network is out of control can be effectively avoided, and the safety of the operation of the energy storage system is further enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0015] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which do not limit the scope of the embodiments in any way. Like referenced numerals in the drawings indicate like elements and do not limit the scope of the embodiments. The figures are not drawn to scale and are not intended to limit the scope of the embodiments.

[0016] Figure 1 A structural block diagram of an energy storage system provided for an embodiment of the present application; Figure 2 A structural diagram of a resonant conversion module provided for an embodiment of the present application; Figure 3 A flowchart of a soft start method of a resonant conversion module provided for an embodiment of the present application; Figure 4 A waveform schematic diagram of a pulse width modulation signal of a primary side switch tube and a resonant current provided for an embodiment of the present application; Figure 5 A waveform schematic diagram of a pulse width modulation signal of a primary side switch tube and a resonant current provided for another embodiment of the present application; Figure 6 A waveform schematic diagram of a voltage of a high-voltage bus side provided for an embodiment of the present application; Figure 7 A structural block diagram of a control unit provided for an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intervening elements can be present therebetween. When an element is described as "electrically connected to" another element, it can be directly connected to the other element or one or more intervening elements can be present therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in the present specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", etc. are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0018] Unless otherwise defined, all technical and scientific terms used in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference. In case of a conflict between the present specification and a reference incorporated by reference, the present specification will control. In addition, the various embodiments of the application described below are not intended to limit the application unless otherwise specified.

[0019] The embodiments of the present application provide a kind of energy storage system, refer to Figure 1 The energy storage system includes DCDC module 10, resonant conversion module 20 and inverter module 30. Resonant conversion module 20 includes primary side switch tube group and secondary side switch tube group, primary side switch tube group is connected DCDC module 10, secondary side switch tube group is connected inverter module 30.

[0020] Wherein, DCDC module 10 refers to the voltage amplitude of adjustable direct current device, can realize the conversion between different voltage grade direct current. DCDC module 10 is also used to connect battery, battery includes a plurality of parallel, series or mixed connection electric core, for storing and providing electric energy, mixed connection includes series and parallel, the working voltage range of battery can be 20V-40V.

[0021] Wherein, resonant conversion module 20 is a kind of high-efficiency direct current conversion converter using resonant soft switching technology, it can realize the isolation conversion of high-low voltage direct current. In some embodiments, refer to Figure 2 Resonant conversion module 20 is LLC resonant converter, which includes primary side switch tube group, secondary side switch tube group, transformer T1, resonant unit and control unit, primary side switch tube group is connected to the primary side of transformer T1, the secondary side of transformer T1 is connected to the first end of resonant unit, the second end of resonant unit is connected to secondary side switch tube group, control unit is connected to primary side switch tube group and secondary side switch tube group, primary side switch tube group includes four primary side switch tubes, which are primary side switch tube Q5, primary side switch tube Q6, primary side switch tube Q7 and primary side switch tube Q8, secondary side switch tube group includes four secondary side switch tubes, which are secondary side switch tube Q9, secondary side switch tube Q10, secondary side switch tube Q11 and secondary side switch tube Q12, resonant unit includes resonant inductance Lr and resonant capacitor Cr, resonant conversion module 20 also includes low-voltage bus capacitor CLbus and high-voltage bus capacitor CHbus. In Figure 2 The sampling voltage between A1 connection point and A2 connection point is the sampling voltage of low-voltage bus side, and the sampling voltage between A3 connection point and A4 connection point is the sampling voltage of high-voltage bus side.

[0022] The inverter module 30 is an electronic power device that can convert DC power into AC power and vice versa. The inverter module 30 is also used to connect the power grid and the load. When it is in the grid-connected working mode, it can convert the AC power of the power grid into DC power on the high-voltage bus side. When it is in the off-grid working mode, it can convert DC power into AC power to power the load.

[0023] In this energy storage system, a fixed-step soft-start resonant conversion module 20 is often used. However, when the step size is set to a small value, although the risk of overcurrent can be effectively avoided, the time required for the soft-start process will be increased, resulting in the energy storage system being unable to reach normal operating state in a short time, affecting the starting efficiency of the energy storage system. When the step size is set to a large value, although the time consumption of the soft-start process can be shortened, in the initial stage, the inductor current in the resonant network will rise rapidly due to the sharp change in the duty cycle. Once the inductor current exceeds its preset peak limit, an overcurrent phenomenon will occur, which will not only damage the inductor element, but may also affect the entire converter, reduce its reliability, shorten its service life, and pose a potential threat to the stable operation of the energy storage system.

[0024] In order to improve the above-mentioned problems, the embodiments of the present application provide a resonant conversion module and its soft start method, a control unit and an energy storage system. By dynamically setting the duty cycle step in stages, the soft start time is reduced and the soft start efficiency is improved. By setting the duty cycle step in each adjustment stage by multiple parameters, the inductive current of the resonant network is avoided from being out of control, thereby improving the safety of the energy storage system.

[0025] The embodiment of the present application provides a soft start method for a resonant conversion module, which is applied to the resonant conversion module as described above. Figure 3 The soft start method includes steps S10 to S60.

[0026] Step S10: Divide the range from the primary side initial duty cycle to the primary side soft start target duty cycle into a plurality of primary side duty cycle adjustment stages, and obtain a stage target duty cycle of each primary side duty cycle adjustment stage.

[0027] The primary initial duty cycle refers to the on-duty cycle of the primary switch tube group at the initial adjustment moment, which can be the minimum on-duty cycle of each switch tube in the primary switch tube group, that is, it can be the minimum on-duty cycle of the primary switch tube Q5, the primary switch tube Q6, the primary switch tube Q7, and the primary switch tube Q8.

[0028] The primary side soft start target duty cycle refers to the target conduction duty cycle of each primary side switch tube in the primary side switch tube group. Specifically, the inductance value of the resonant inductor Lr can be determined based on the voltage on the low voltage bus side, the voltage on the high voltage bus side and the output power of the resonant conversion module. , the capacitance value of the resonant capacitor Cr and the inductance value of the magnetizing inductance Lm Then, the resonant frequency of the resonant conversion module is calculated according to the following formula: : ; Then, the switching frequency of the resonant conversion module is The following relationship must be satisfied: ; in, The maximum supported frequency of each switch in the resonant conversion module, that is, the maximum switching frequency allowed by the primary switch Q5, the primary switch Q6, the primary switch Q7, the primary switch Q8, the secondary switch Q9, the secondary switch Q10, the secondary switch Q11 and the secondary switch Q12. Afterwards, the target duty cycle of the primary side soft start can be determined using an oscilloscope. It can be understood that the target duty cycle of the primary side soft start needs to be less than 50% to ensure that there is sufficient dead time between the primary side switches Q5, Q6, Q7, and Q8. The dead time can be adjusted according to the resonant current to ensure that the primary side switch is turned off when the resonant current flowing through the resonant inductor Lr is 0.

[0029] Specifically, such as Figure 4 As shown, at time 1, the resonant current flowing through the resonant inductor Lr is 0, but the primary switch Q5 is not turned off at this time. At this time, the deviation between the primary soft start target duty cycle and the current duty cycle of the primary switch Q5 is the duty cycle deviation. , so it is necessary to base it on the duty cycle deviation Obtain the primary side soft start target duty cycle, such as the primary side soft start target duty cycle calculated using the following formula: ; ; in, is the target duty cycle of the primary side soft start, To compensate for the duty cycle, is the switching frequency, is the duty cycle of the primary switch Q5 at the current (time1 moment). Figure 5 As shown, at time 2, when the duty cycle of the primary side switch tube Q5 reaches the primary side soft start target duty cycle, the resonant current flowing through the resonant inductor Lr is 0, and the primary side switch tube Q5 is turned off.

[0030] Step S20: setting the duty cycle step size of each primary side duty cycle adjustment stage according to the maximum resonant current peak of the resonant conversion module, the set voltage effective value of the low voltage bus side for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage.

[0031] The duty cycle step length of each primary side duty cycle adjustment stage refers to a duty cycle increment used when adjusting the duty cycle of the primary side switch tube each time in each primary side duty cycle adjustment stage.

[0032] Specifically, after obtaining the maximum resonant current peak value of the resonant conversion module, the set voltage effective value of the low voltage bus side for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage, the duty cycle step length of each primary side duty cycle adjustment stage is calculated by using a pre-set calculation formula.

[0033] Step S30: According to the duty cycle step length of each primary side duty cycle adjustment stage and the duty cycle preset accumulation time length, the soft start of the duty cycle of each adjustment stage is completed until the duty cycle of the primary side switch tube reaches the primary side soft start target duty cycle.

[0034] The duty cycle preset accumulation time length of each primary side duty cycle adjustment stage refers to an adjustment period in each primary side duty cycle adjustment stage, that is, in each primary side duty cycle adjustment stage, the duty cycle of the primary side switch tube group is adjusted once every corresponding duty cycle preset accumulation time length, and at each adjustment, the duty cycle of the primary side switch tube group is adjusted by using the corresponding duty cycle step length until the duty cycle of the primary side switch tube group reaches the corresponding stage target duty cycle, completing the primary side duty cycle adjustment stage and entering the next primary side duty cycle adjustment stage.

[0035] Step S40: The range from the secondary side initial duty cycle to the secondary side soft start target duty cycle is divided into multiple secondary side duty cycle adjustment stages, and the stage target duty cycle of each secondary side duty cycle adjustment stage is obtained.

[0036] The secondary side initial duty cycle refers to the on-duty cycle of the secondary side switch tube group at the initial adjustment moment, which can be the minimum on-duty cycle of each secondary side switch tube in the secondary side switch tube group, that is, the minimum on-duty cycle of the secondary side switch tube Q9, the secondary side switch tube Q10, the secondary side switch tube Q11, and the secondary side switch tube Q12.

[0037] The secondary side soft start target duty cycle refers to the target on-duty cycle of each secondary side switch tube in the secondary side switch tube group. Its specific determination process can refer to the determination process of the primary side soft start target duty cycle, which is not described here.

[0038] Step S50: According to the maximum resonant current peak value of the resonant conversion module, the set voltage effective value of the high voltage bus side for soft start, and the stage target duty cycle of each secondary side duty cycle adjustment stage, the duty cycle step length of each secondary side duty cycle adjustment stage is set.

[0039] The duty cycle step length of each secondary side duty cycle adjustment stage refers to a duty cycle increment used when adjusting the duty cycle of the secondary side switch tube each time in each secondary side duty cycle adjustment stage.

[0040] Specifically, after obtaining the maximum resonant current peak value of the resonant conversion module, the set voltage effective value of the high-voltage bus side for soft starting, and the stage target duty ratio of each secondary side duty ratio adjustment stage, the duty ratio step length of each secondary side duty ratio adjustment stage is calculated by using a pre-set calculation formula.

[0041] Step S60: According to the duty ratio step length of each secondary side duty ratio adjustment stage and the duty ratio preset accumulation time length, the soft starting of the duty ratio of each adjustment stage is completed until the duty ratio of the secondary side switch tube reaches the target duty ratio of the secondary side soft starting.

[0042] The duty ratio preset accumulation time length of each secondary side duty ratio adjustment stage refers to the adjustment period in each secondary side duty ratio adjustment stage, that is, in each secondary side duty ratio adjustment stage, the duty ratio of the secondary side switch tube group is adjusted once every corresponding duty ratio preset accumulation time length, and in each adjustment, the duty ratio of the secondary side switch tube group is adjusted by using the corresponding duty ratio step length until the duty ratio of the secondary side switch tube group reaches the corresponding stage target duty ratio, that is, the secondary side duty ratio adjustment stage is completed, and the next secondary side duty ratio adjustment stage is entered.

[0043] It can be understood that the magnetic force inductance of the resonant cavity and other magnetic devices may be affected by temperature, current size (DC bias) passing through the magnetic device, etc., which may cause the actual inductance to decrease, thereby reducing the impedance of the resonant cavity, causing the current peak value of the resonant inductance of the resonant cavity to be too large at the moment, that is, causing the switch tube to be damaged, the inductance to be oversaturated, etc. In the embodiment, by gradually adjusting the duty ratio of the primary side switch tube group and the secondary side switch tube group in stages, the purpose of gradually increasing the current of the magnetic force inductance or the current passing through the switch tube can be achieved to reduce the risk of damage to circuit elements. In addition, compared with the soft starting scheme of using a fixed step length to soft start the duty ratio of the primary side switch tube group and the secondary side switch tube group, the step length is difficult to set, and if the fixed step length is too small, the soft starting efficiency of the system is too slow, and if the fixed step length is too large, the change of the duty ratio of the switch tube is too large, which causes the inductance current of the resonant network of the resonant conversion module to be out of control, thereby causing the switch tube to be damaged, the inductance to be oversaturated, etc. In the embodiment, by dynamically adjusting the duty ratio step length of the primary side switch tube group and the secondary side switch tube group in stages, the duty ratio step length and the adjustment interval are designed differently in each primary side duty ratio adjustment stage and secondary side duty ratio adjustment stage, the soft starting time is reduced, the soft starting efficiency is improved, and by setting the step length with multiple parameters, the inductance current of the resonant network can be prevented from being out of control, and the safety of the energy storage system is improved.

[0044] In some embodiments, for step S10, the range from the primary side initial duty ratio to the primary side soft start target duty ratio is divided into multiple primary side duty ratio adjustment stages, including the following steps S11 to S14. Step S11: set the first quarter of the primary side soft start target duty ratio as the first primary side duty ratio adjustment stage. Step S12: set the second quarter of the primary side soft start target duty ratio to the first half of the primary side soft start target duty ratio as the second primary side duty ratio adjustment stage. Step S13: set the first half of the primary side soft start target duty ratio to a first preset duty ratio value as the third primary side duty ratio adjustment stage, wherein the first preset duty ratio value is the difference between the primary side soft start target duty ratio and a first preset threshold value, the first preset threshold value is greater than 0, and the first preset threshold value is less than the first half of the primary side soft start target duty ratio. Step S14: set the first preset duty ratio value to the primary side soft start target duty ratio as the fourth primary side duty ratio adjustment stage.

[0045] That is, the stage target duty ratio of the first primary side duty ratio adjustment stage is one quarter of the primary side soft start target duty ratio, that is, in the first primary side duty ratio adjustment stage, the duty ratio of the primary side switch tube group is adjusted from the primary side initial duty ratio to one quarter of the primary side soft start target duty ratio. The stage target duty ratio of the second primary side duty ratio adjustment stage is one half of the primary side soft start target duty ratio, that is, in the second primary side duty ratio adjustment stage, the duty ratio of the primary side switch tube group is adjusted from one quarter of the primary side soft start target duty ratio to one half of the primary side soft start target duty ratio. The stage target duty ratio of the third primary side duty ratio adjustment stage is the first preset duty ratio value, that is, in the third primary side duty ratio adjustment stage, the duty ratio of the primary side switch tube group is adjusted from one half of the primary side soft start target duty ratio to the first preset duty ratio value. The stage target duty ratio of the fourth primary side duty ratio adjustment stage is the primary side soft start target duty ratio, that is, in the fourth primary side duty ratio adjustment stage, the duty ratio of the primary side switch tube group is adjusted from the first preset duty ratio value to the primary side soft start target duty ratio. The first preset threshold value is a preset threshold value used to determine the stage target duty ratio of the third primary side duty ratio adjustment stage, which can be 10 in actual application without limitation.

[0046] In this embodiment, by adjusting the duty ratio of the primary side switch tube group from the primary side initial duty ratio to the primary side soft start target duty ratio in stages, the adjustment process is smoother, which helps to reduce the current impact during the soft start process of the resonant conversion module and protect the equipment from damage.

[0047] In some embodiments, step S20 includes: the duty ratio step length of the first primary side duty ratio adjustment stage satisfies the following relationship: ; ; ; wherein, is the peak value of the conduction current of the primary side switch tube in the first primary side duty cycle adjustment phase, is the resonant cavity impedance of the resonant conversion module, is the set voltage effective value of the low-voltage bus side for soft start, is the phase target duty cycle of the first primary side duty cycle adjustment phase, is the voltage value across the resonant inductance of the resonant cavity at the start of the first primary side duty cycle adjustment phase.

[0048] Understandably, the maximum value of the duty cycle step length of the first primary side duty cycle adjustment phase is: .

[0049] wherein, the resonant cavity impedance of the resonant conversion module can be calculated according to the following formula: ; ; wherein, is the inductance value of the resonant inductance Lr, is the capacitance value of the resonant capacitance Cr, is the switching angle frequency, is the switching frequency of the resonant conversion module.

[0050] It is worth mentioning that, since in the primary side duty cycle soft start process, the high-voltage bus side capacitor CHbus is charged by the primary side, the voltage of the high-voltage bus side will gradually increase, and the change of the high-voltage bus side voltage is generally as shown in the following formula: Figure 6 In the early stage of duty cycle adjustment, the slope of the change of the high-voltage bus side voltage is large, that is, the growth of the high-voltage bus side voltage is large, so the step length of the adjustment of the duty cycle cannot be too large, so as to prevent the resonant inductance current from being too large; in the later stage of duty cycle adjustment, the change of the high-voltage bus side voltage is gentle, that is, the growth of the high-voltage bus side voltage is small, at this time the adjustment step length can be larger than that in the early stage. For the primary side duty cycle adjustment phase, there is a maximum value for , and the maximum value is determined; since the primary side duty cycle is continuously increased in the multiple primary side duty cycle adjustment processes , the is gradually increased, and then is gradually increased, so the last stage the maximum value of the second stage will be larger than that of the first stage , and the step size selection range will be larger and larger.

[0051] In this embodiment, the selection range of the duty cycle step size of each primary side duty cycle adjustment stage is calculated by the above formula, which ensures that the resonant inductor current will not be too large during the adjustment process, thereby protecting the primary side switch tube and other elements in the resonant conversion module from damage caused by excessive current.

[0052] In some embodiments, the value of the duty cycle step size of the first primary side duty cycle adjustment stage is greater than the value of the duty cycle step size of the second primary side duty cycle adjustment stage. That is, in the plurality of primary side duty cycle adjustment stages, the duty cycle step size of the later primary side duty cycle adjustment stage is larger, thereby accelerating the adjustment speed of the duty cycle and improving the soft start efficiency of the resonant conversion module.

[0053] That is, in the plurality of primary side duty cycle adjustment stages, the duty cycle step size of the later primary side duty cycle adjustment stage is larger, thereby accelerating the adjustment speed of the duty cycle and improving the soft start efficiency of the resonant conversion module.

[0054] For example, the first preset threshold is 10, and the initial value of the primary side initial duty cycle is used to adjust the duty cycle. In the first primary side duty cycle adjustment stage, the duty cycle step size is 1, and the initial primary side duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 2ms. That is, in the first primary side duty cycle adjustment stage, the duty cycle is adjusted by 1 every 2ms until the primary side duty cycle reaches the stage target duty cycle ; in the second primary side duty cycle adjustment stage, the duty cycle step size is 2, and the stage target duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 1ms, that is, in the second primary side duty cycle adjustment stage, the duty cycle is adjusted by 2 every 1ms until the stage target duty cycle is adjusted to the stage target duty cycle ; in the third primary side duty cycle adjustment stage, the duty cycle step size is 5, and the stage target duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 1ms, that is, in the third primary side duty cycle adjustment stage, the duty cycle is adjusted by 5 every 1ms until the stage target duty cycle is adjusted to the stage target duty cycle ; in the fourth primary side duty cycle adjustment stage, ​​​​​It needs to be set to a value less than the first preset threshold value, and the stage target duty cycle Adjust to the primary side soft start target duty cycle.

[0055] In this embodiment, by adjusting the step size in stages and using a smaller step size in the early stage of the primary side duty cycle adjustment, a smooth system startup can be ensured and sudden changes in voltage and current can be avoided; by using a larger step size in the later stage of the primary side duty cycle adjustment, the adjustment speed can be accelerated and the startup time can be shortened.

[0056] In some embodiments, step S40 divides the range from the initial secondary side duty cycle to the secondary side soft start target duty cycle into multiple secondary side duty cycle adjustment stages, including the following steps S41 to S44. Step S41: Setting the current secondary side duty cycle to one-quarter of the secondary side soft start target duty cycle as the first secondary side duty cycle adjustment stage. Step S42: Setting the range from one-quarter of the secondary side soft start target duty cycle to one-half of the secondary side soft start target duty cycle as the second secondary side duty cycle adjustment stage. Step S43: Setting one-half of the secondary side soft start target duty cycle to a second preset duty cycle value as the third secondary side duty cycle adjustment stage, wherein the second preset duty cycle value is the difference between the secondary side soft start target duty cycle and the second preset threshold value, the second preset threshold value is greater than 0, and the second preset threshold value is less than one-half of the secondary side soft start target duty cycle. Step S44: Setting the second preset duty cycle value to the secondary side soft start target duty cycle as the fourth secondary side duty cycle adjustment stage.

[0057] That is to say, the target duty cycle of the first secondary duty cycle adjustment stage is The secondary side soft start target duty cycle is one quarter of the secondary side soft start target duty cycle, that is, in the first secondary side duty cycle adjustment stage, the duty cycle of the secondary side switch group is adjusted from the secondary side initial duty cycle to one quarter of the secondary side soft start target duty cycle. The second secondary side duty cycle adjustment stage target duty cycle is The target duty cycle of the secondary side soft start is half, that is, in the second secondary side duty cycle adjustment stage, the duty cycle of the secondary side switch group is adjusted from one quarter of the secondary side soft start target duty cycle to one half of the secondary side soft start target duty cycle. The target duty cycle of the third secondary side duty cycle adjustment stage is The first preset duty cycle value is used, that is, in the third secondary side duty cycle adjustment stage, the duty cycle of the secondary side switch group is adjusted from half of the secondary side soft start target duty cycle to the first preset duty cycle value. The stage target duty cycle of the fourth secondary side duty cycle adjustment stage is is the secondary side soft-start target duty cycle. That is, in the fourth secondary side duty cycle adjustment stage, the duty cycle of the secondary side switch group is adjusted from the first preset duty cycle value to the secondary side soft-start target duty cycle. The second preset threshold is a pre-set threshold used to determine the stage target duty cycle in the third secondary side duty cycle adjustment stage. For example, it can be 10, but this is not limited in actual application.

[0058] In this embodiment, the duty cycle of the secondary side switch tube group is adjusted from the secondary side initial duty cycle to the secondary side soft start target duty cycle in stages, so that the adjustment process is smoother, which helps to reduce the current shock during the soft start process of the resonant conversion module and protect the equipment from damage.

[0059] In some embodiments, step S50 includes: Duty cycle step size of each secondary side duty cycle adjustment stage Satisfies the following relationship: ; ; ; in, For the The peak current of the secondary side switch tube in the secondary side duty cycle adjustment stage, is the resonant cavity impedance of the resonant conversion module, is the effective value of the voltage on the high-voltage bus side set for soft start, For the The target duty cycle of each secondary side duty cycle adjustment stage, For the The voltage value across the resonant inductor of the resonant cavity at the beginning of the secondary side duty cycle adjustment phase.

[0060] Understandably, The maximum step length of each secondary side duty cycle adjustment stage is .

[0061] It is worth noting that during the secondary duty cycle soft start process, the secondary side charges the low voltage bus side capacitor CLbus of the primary side, so the voltage of the low voltage bus side will gradually increase. The change of the low voltage bus side voltage is generally consistent with the Figure 6 The changes in the voltage on the medium and high voltage bus side are similar. In the early stage of duty cycle adjustment, the voltage change slope on the low voltage bus side is large, that is, the voltage growth on the low voltage bus side is large, so the duty cycle adjustment step cannot be too large to prevent the resonant inductor current from being too large; in the later stage of duty cycle adjustment, the voltage change on the low voltage bus side is slow, that is, the voltage growth on the low voltage bus side is small, at this time the duty cycle adjustment step can be larger than the early stage. For the secondary side duty cycle adjustment stage, there are some targeted The maximum value of OK; because in the process of adjusting multiple secondary duty cycles is constantly increasing, then It gradually increases, and then Gradually increasing, so the latter stage It will be better than the previous stage The maximum value of the second stage is larger than that of the first stage. The maximum value of the second stage is larger than that of the first stage. The maximum value of the second stage is larger than that of the first stage. The step size selection range will be larger and larger in the subsequent stages.

[0062] In the embodiment, the selection range of the step size of the duty cycle of each secondary side duty cycle adjustment stage is calculated by the above formula, which ensures that the resonant inductor current is not too large during the adjustment process, thereby protecting the secondary side switch tube and other elements in the resonant conversion module from damage caused by excessive current.

[0063] In some embodiments, the value of the duty cycle step size of the first secondary side duty cycle adjustment stage is greater than the value of the duty cycle step size of the second secondary side duty cycle adjustment stage.

[0064] That is, in the plurality of secondary side duty cycle adjustment stages, the step size of the duty cycle of the subsequent stage is larger, thereby accelerating the adjustment speed of the duty cycle and improving the soft start efficiency of the resonant conversion module.

[0065] For example, the first preset threshold is 10, and the initial value of the secondary side initial duty cycle is used to adjust the duty cycle. In the first secondary side duty cycle adjustment stage, the duty cycle step size is 1, and the initial secondary side duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 2ms, that is, in the first secondary side duty cycle adjustment stage, the duty cycle is adjusted by 1 every 2ms, until the secondary side duty cycle reaches the stage target duty cycle ; in the second secondary side duty cycle adjustment stage, the duty cycle step size is 2, and the stage target duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 1ms, that is, in the second secondary side duty cycle adjustment stage, the duty cycle is adjusted by 2 every 1ms, until the stage target duty cycle is adjusted to the stage target duty cycle; in the third secondary side duty cycle adjustment stage, the duty cycle step size is 5, and the stage target duty cycle is adjusted to the stage target duty cycle by a preset cumulative duration of 1ms, that is, in the third secondary side duty cycle adjustment stage, the duty cycle is adjusted by 5 every 1ms, until the stage target duty cycle is adjusted to the stage target duty cycle ; in the fourth secondary side duty cycle adjustment stage, a value less than the first preset threshold needs to be set, and the stage target duty cycle Adjust to the secondary side soft start target duty cycle.

[0066] In the embodiment, by adjusting the step length in stages, and using a smaller step length in the early stage of the secondary side duty cycle adjustment, the system can be ensured to start smoothly, and sudden changes of voltage and current can be avoided; using a larger step length in the late stage of the secondary side duty cycle adjustment, the adjustment speed can be accelerated, and the starting time can be shortened.

[0067] In a second aspect, the embodiment of the application provides a control unit, Figure 7 A hardware structure of the control unit 100 is shown. Please refer to Figure 7 The control unit 100 includes a processor 110, a memory 120 and a communication interface 130, the processor 110, the memory 120 and the communication interface 130 are connected through a line, and the control unit 100 further includes a bus interface 140. Figure 7 In the embodiment shown in the figure, the processor 110, the memory 120 and the communication interface 130 realize the communication connection between each other through the bus.

[0068] The memory 120 is used for storing software programs, computer executable program instructions and the like. The memory 120 can include a storage program area and a storage data area, wherein the storage program area can store an operating system, application programs required by at least one function; the storage data area can store data created according to the use of the control unit 100 and the like.

[0069] The memory 120 can be a read-only memory (read-only memory, ROM), can be other types of static storage devices that can store static information and instructions, can be a random access memory (random access memory, RAM), can be other types of dynamic storage devices that can store information and instructions, and can be an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), which is not limited here.

[0070] For example, the aforementioned memory 120 can be a double data rate synchronous dynamic random access memory (double data rate synchronous dynamic random access memory, DDR for short). The memory 120 can exist independently, but is connected with the processor 110. Optionally, the memory 120 can also be integrated with the processor 110. For example, integrated in one or more chips.

[0071] In some embodiments, the memory 120 can optionally include a memory remotely arranged relative to the processor 110, and these remote memories can be connected to the control unit 100 through a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0072] The processor 110 utilizes various interfaces and lines to connect various parts of the control unit 100, and performs various functions of the control unit 100 and processes data by running or executing software programs stored in the memory 120 and calling data stored in the memory 120, such as implementing the method described in any embodiment of the present application.

[0073] The processor 110 can be a field programmable gate array (FPGA), a digital signal process (DSP), a central processing unit (CPU), etc.

[0074] The processor 110 can be a single-core processor 110 or a multi-core processor 110, for example, the processor 110 can be composed of multiple FPGAs or multiple DSPs. In addition, the processor 110 can refer to one or more devices, circuits and / or processing cores for processing data (such as computer program instructions). The processor 110 can be a separate semiconductor chip, or can be integrated with other circuits as a semiconductor chip, for example, it can be integrated with other circuits (such as coding and decoding circuits, hardware acceleration circuits or various bus and interface circuits) to form a system-on-a-chip (SoC), or it can be integrated as a built-in processor 110 in an application specific integrated circuit (ASIC), and the ASIC integrated with the processor 110 can be packaged separately or packaged together with other circuits.

[0075] The communication interface 130 can use a transceiver device such as a transceiver to realize communication between the control unit 100 and other devices or communication networks.

[0076] In a third aspect, the embodiments of the present application also provide a resonant conversion module, which comprises a primary switch tube group, a secondary switch tube group, a transformer, a resonant unit and a control unit as described in the second aspect. The primary switch tube group is connected to the primary side of the transformer, the secondary side of the transformer is connected to the first end of the resonant unit, the second end of the resonant unit is connected to the secondary switch tube group, and the control unit is connected to the primary switch tube group and the secondary switch tube group.

[0077] In the present embodiment, the control unit has the same structure and function as the control unit described in the second aspect, and will not be described here.

[0078] The embodiment of the present application further provides a storage system, which comprises a DCDC module, an inverter module and the resonant conversion module as described in the third aspect. The resonant conversion module comprises a primary switch tube group and a secondary switch tube group, the primary switch tube group is connected to the DCDC module, and the secondary switch tube group is connected to the inverter module.

[0079] In the embodiment, the resonant conversion module has the same structure and function as the resonant conversion module as described in the third aspect, and details are not repeated here.

[0080] The embodiment of the present application further provides a computer storage medium, which stores instructions or programs, and the instructions or programs are executed by one or more processors, for example, one processor 110 in the computer storage medium, so that the one or more processors can execute the soft start method in any method embodiment. Figure 7

[0081] The embodiment of the present application further provides a computer program product, which comprises a computer program stored in a computer storage medium, and the computer program comprises programs or instructions, and when the programs or instructions are executed by an electronic device, the electronic device executes the soft start method in any embodiment.

[0082] It should be noted that the apparatus embodiments described above are only schematic, and the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0083] From the above description of the embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as a ROM / RAM, a magnetic disk, or an optical disk) and includes a number of instructions for making a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device) execute the methods described in the various embodiments of the present application.

[0084] ​Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; under the idea of the present application, the technical features in the above examples or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in details for simplicity; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A soft start method for a resonant conversion module, characterized in that: The resonant conversion module includes a primary switch tube group and a secondary switch tube group, wherein the primary switch tube group includes four primary switch tubes and the secondary switch tube group includes four secondary switch tubes. The soft start method includes: Dividing the range from the primary side initial duty cycle to the primary side soft start target duty cycle into multiple primary side duty cycle adjustment stages, and obtaining the stage target duty cycle of each primary side duty cycle adjustment stage; Setting the duty cycle step size of each primary side duty cycle adjustment stage according to the maximum resonant current peak value of the resonant conversion module, the set voltage effective value of the low voltage bus side for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage; According to the duty cycle step size and the preset duty cycle accumulation time of each primary side duty cycle adjustment stage, the duty cycle soft start of each adjustment stage is completed until the duty cycle of the primary side switch tube reaches the primary side soft start target duty cycle; Divide the range from the secondary side initial duty cycle to the secondary side soft start target duty cycle into multiple secondary side duty cycle adjustment stages, and obtain the stage target duty cycle of each secondary side duty cycle adjustment stage; Setting the duty cycle step size of each secondary side duty cycle adjustment stage according to the maximum resonant current peak value of the resonant conversion module, the set voltage effective value of the high-voltage bus side for soft start, and the stage target duty cycle of each secondary side duty cycle adjustment stage; According to the duty cycle step size and the preset duty cycle accumulation time of each secondary side duty cycle adjustment stage, the duty cycle soft start of each adjustment stage is completed until the duty cycle of the secondary side switch tube reaches the secondary side soft start target duty cycle.

2. The soft start method according to claim 1, wherein: The range from the primary side initial duty cycle to the primary side soft start target duty cycle is divided into multiple primary side duty cycle adjustment stages, including: Setting the current primary side duty cycle to one quarter of the primary side soft start target duty cycle is the first primary side duty cycle adjustment stage; Setting a range from one quarter of the primary side soft start target duty cycle to one half of the primary side soft start target duty cycle as a second primary side duty cycle adjustment stage; Setting a value from half of the primary soft start target duty cycle to a first preset duty cycle value as a third primary duty cycle adjustment stage, wherein the first preset duty cycle value is a difference between the primary soft start target duty cycle and a first preset threshold value, the first preset threshold value is greater than 0, and the first preset threshold value is less than half of the primary soft start target duty cycle; Setting the first preset duty cycle value to the primary side soft start target duty cycle is a fourth primary side duty cycle adjustment stage.

3. The soft start method according to claim 1, wherein: The duty cycle step size of each primary side duty cycle adjustment stage is set according to the maximum resonant current peak of the resonant conversion module, the set voltage effective value of the low voltage bus side for soft start, and the stage target duty cycle of each primary side duty cycle adjustment stage, including: No. Duty cycle step size of the primary side duty cycle adjustment stage Satisfies the following relationship: ； ； ； in, For the The peak current of the primary switch tube in the primary duty cycle adjustment stage, is the resonant cavity impedance of the resonant conversion module, is the voltage effective value of the low voltage bus side set for soft start, For the The target duty cycle of the primary side duty cycle adjustment stage, For the The voltage value across the resonant inductor of the resonant cavity at the beginning of the primary side duty cycle adjustment stage.

4. The soft start method according to claim 3, characterized in that: No. The duty cycle step value of the first primary side duty cycle adjustment stage is greater than the first The value of the duty cycle step in the primary side duty cycle adjustment stage.

5. The soft start method according to any one of claims 1 to 4, characterized in that: The range from the secondary side initial duty cycle to the secondary side soft start target duty cycle is divided into multiple secondary side duty cycle adjustment stages, including: Setting the current secondary side duty cycle to one quarter of the secondary side soft start target duty cycle is the first secondary side duty cycle adjustment stage; Setting a second secondary side duty cycle adjustment stage from one quarter of the secondary side soft start target duty cycle to one half of the secondary side soft start target duty cycle; Setting a third secondary side duty cycle adjustment stage from half of the secondary side soft start target duty cycle to a second preset duty cycle value, wherein the second preset duty cycle value is a difference between the secondary side soft start target duty cycle and a second preset threshold value, and the second preset threshold value is greater than 0 and less than half of the secondary side soft start target duty cycle; Setting the second preset duty cycle value to the secondary side soft start target duty cycle is a fourth secondary side duty cycle adjustment stage.

6. The soft start method according to any one of claims 1 to 4, characterized in that: The duty cycle step size of each secondary side duty cycle adjustment stage is set according to the maximum resonant current peak of the resonant conversion module, the set voltage effective value of the high-voltage bus side for soft start, and the stage target duty cycle of each secondary side duty cycle adjustment stage, including: No. Duty cycle step size of each secondary side duty cycle adjustment stage Satisfies the following relationship: ； ； ； in, For the The peak current of the secondary side switch tube in the secondary side duty cycle adjustment stage, is the resonant cavity impedance of the resonant conversion module, is the voltage effective value of the low voltage bus side set for soft start, For the The target duty cycle of each secondary side duty cycle adjustment stage, For the The voltage value across the resonant inductor of the resonant cavity at the beginning of the secondary side duty cycle adjustment phase.

7. The soft start method according to claim 6, characterized in that: No. The duty cycle value step size of the secondary side duty cycle adjustment stage is greater than the The duty cycle step value of each secondary side duty cycle adjustment stage.

8. A control unit, characterized in that: include: at least one processor and memory; The memory is connected to the processor, and the memory is used to store instructions or programs. When the instructions or programs are executed by the control unit, the control unit executes the soft start method according to any one of claims 1 to 7.

9. A resonant conversion module, characterized in that: include: A primary side switch tube group, a secondary side switch tube group, a transformer, a resonant unit and a control unit as claimed in claim 8; The primary switch tube group is connected to the primary side of the transformer, the secondary side of the transformer is connected to the first end of the resonance unit, the second end of the resonance unit is connected to the secondary switch tube group, and the control unit is connected to the primary switch tube group and the secondary switch tube group.

10. An energy storage system, characterized in that: It includes a DCDC module, an inverter module and the resonant conversion module according to claim 9; The resonant conversion module includes a primary switch tube group and a secondary switch tube group. The primary switch tube group is connected to the DCDC module, and the secondary switch tube group is connected to the inverter module.

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