Power conversion system and control method and device therefor, and readable storage medium

Abstract

The present application relates to the technical field of power electronics, and provides a power conversion system and a control method and device therefor, and a readable storage medium. The power conversion system comprises: a direct current converter module and an alternating current converter module; the direct current converter module further comprises a first semiconductor assembly, an inductor assembly, a fourth capacitor and a neutral-point balance branch; the first semiconductor assembly is used for adjusting the voltage value of the fourth capacitor, so that the voltage value of the fourth capacitor can be larger than a first preset value and smaller than a second preset value; and the first semiconductor assembly is also used for adjusting the voltage value of a third capacitor, so that the voltage value of the third capacitor is a third preset value. The neutral-point balance branch is used for adjusting the voltage value of a first capacitor and the voltage value of a second capacitor, to make the voltage value of the first capacitor and the voltage value of the second capacitor both equal to a fourth preset value.

Description

Energy storage converter, control method, device and readable storage medium thereof

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 23, 2023, with application number "202311574597.6" and invention name "Energy Storage Converter and Control Method, Device and Readable Storage Medium thereof", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power electronics technology, and in particular to an energy storage converter and a control method, device, and readable storage medium thereof. Background Art

[0003] In the related art, energy storage converters usually adopt a two-stage structure. The first stage is a DC-DC converter module (referred to as DC-DC converter), one side of which is connected to the battery and the other side is connected to the bus capacitor, providing a stable DC voltage value. The second stage is a DC-AC converter module (referred to as DC-AC converter), one side of which is connected to the bus capacitor and the other side is connected to the power grid or load. However, although the DC converter module in the energy storage converter has a bidirectional boost function, when the battery voltage value and the bus voltage value differ greatly, the current ripple on the DC inductor is large, resulting in low efficiency of the energy storage converter.

[0004] Summary of the Invention

[0005] This application aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] To this end, a first aspect of the present application is to propose an energy storage converter.

[0007] The second aspect of the present application is to propose a control method for an energy storage converter.

[0008] The third aspect of the present application is to provide a control device for an energy storage converter.

[0009] The fourth aspect of the present application is to provide another control device for an energy storage converter.

[0010] A fifth aspect of the present application is to provide a readable storage medium.

[0011] In view of this, according to a first aspect of the present application, an energy storage converter is proposed for converting a DC power supply into an AC power supply. The energy storage converter includes:

[0012] The first port and the second port are used to connect to a first DC power supply;

[0013] A DC converter module includes a first capacitor and a second capacitor, wherein one end of the first capacitor is connected to the first port, the other end of the first capacitor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the second port;

[0014] The DC converter module further includes a first semiconductor assembly, which includes a first semiconductor device, a second semiconductor device, a third semiconductor device, and a fourth semiconductor device. The first end of the first semiconductor device is connected to the first capacitor, the second end of the first semiconductor device is connected to the first end of the second semiconductor device, the second end of the second semiconductor device is connected to the first end of the third semiconductor device, the second end of the third semiconductor device is connected to the first end of the fourth semiconductor device, and the second end of the fourth semiconductor device is connected to the second capacitor.

[0015] The DC converter module further includes a third capacitor, one end of the third capacitor is connected to the second end of the first semiconductor device, and the other end of the third capacitor is connected to the second end of the third semiconductor device;

[0016] an inductor component, one end of the inductor component being connected to the second end of the second semiconductor device;

[0017] a fourth capacitor, one end of the fourth capacitor being connected to the other end of the inductor component, and the other end of the fourth capacitor being connected to the second port;

[0018] The DC converter module further includes a midpoint balancing branch, a first end of the midpoint balancing branch being connected to the other end of the first capacitor, a second end of the midpoint balancing branch being connected to one end of the third capacitor, and a third end of the midpoint balancing branch being connected to the other end of the third capacitor;

[0019] an AC converter module, one end of the AC converter module being connected to the other end of the inductor assembly, and the other end of the AC converter module being connected to the second port, the AC converter module being used to convert the DC power output by the DC converter module into AC power;

[0020] The first semiconductor component is used to adjust the voltage value of the fourth capacitor so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value;

[0021] The first semiconductor component is further used to adjust the voltage value of the third capacitor so that the voltage value of the third capacitor is a third preset value;

[0022] The midpoint balancing branch is used to adjust the voltage value of the first capacitor and the voltage value of the second capacitor so that the voltage value of the first capacitor and the voltage value of the second capacitor are equal to a fourth preset value.

[0023] The energy storage converter in this technical solution, through the provision of a DC converter module, can adjust the voltage value of the fourth capacitor to maintain it between a first preset value and a second preset value during operation in environments with high DC voltage and low AC voltage. This minimizes the current ripple of the inductor component and prevents large current ripple in the inductor component from reducing the efficiency of the energy storage converter. Simultaneously, the midpoint balancing branch adjusts the voltage values ​​of the first and second capacitors to the fourth preset value to ensure the stability of the energy storage converter's operation.

[0024] According to a second aspect of the present application, a control method for an energy storage converter is proposed. The energy storage converter is the energy storage converter defined in the first aspect. The energy storage converter is connected to a first DC power supply. The control method for the energy storage converter includes:

[0025] Determining a first preset value according to a target output voltage value of the energy storage converter;

[0026] Determining a second preset value according to an operating parameter of the AC converter module;

[0027] The first semiconductor component is controlled so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

[0028] The control method of the energy storage converter in the present technical solution can adjust the voltage value of the fourth capacitor during operation in situations where the DC voltage value is high and the AC voltage value is low by controlling the DC converter module, so that the voltage value of the fourth capacitor is maintained between the first preset value and the second preset value, thereby minimizing the current ripple of the inductor component and avoiding a reduction in the efficiency of the energy storage converter caused by a large current ripple of the inductor component.

[0029] According to a third aspect of the present application, a control device for an energy storage converter is provided. The energy storage converter is the energy storage converter defined in the first aspect. The energy storage converter is connected to a first DC power supply. The control device for the energy storage converter includes:

[0030] an acquisition module, determining a first preset value according to a target output voltage value of the energy storage converter; and

[0031] Determining a second preset value according to an operating parameter of the AC converter module;

[0032] The control module is used to control the first semiconductor component so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

[0033] The control device of the energy storage converter in the present technical solution can adjust the voltage value of the fourth capacitor during operation in situations where the DC voltage value is high and the AC voltage value is low by controlling the DC converter module, so that the voltage value of the fourth capacitor is maintained between the first preset value and the second preset value, thereby minimizing the current ripple of the inductor component and avoiding the current ripple of the inductor component being large and causing the efficiency of the energy storage converter to be reduced.

[0034] According to a fourth aspect of the present application, a control device for an energy storage converter is provided, comprising a processor and a memory, wherein the memory stores a program or instruction. When executed by the processor, the program or instruction implements the steps of the energy storage converter control method described in any of the above technical solutions. Therefore, the control device for an energy storage converter has all the beneficial effects of the energy storage converter control method described in any of the above technical solutions, and no further details are given here.

[0035] According to a fifth aspect of the present application, a readable storage medium is provided, on which a program or instruction is stored. When executed by a processor, the program or instruction implements the energy storage converter control method described in any of the above technical solutions. Therefore, the readable storage medium has all the beneficial effects of the energy storage converter control method described in any of the above technical solutions, and no further description is given here.

[0036] Additional aspects and advantages of the present application will become apparent in the following description or may be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0038] FIG1 shows one of the circuit diagrams of the energy storage converter in an embodiment of the present application;

[0039] FIG2 shows a second circuit diagram of the energy storage converter in an embodiment of the present application;

[0040] FIG3 shows one of the flow charts of the control method of the energy storage converter in the embodiment of the present application;

[0041] FIG4 shows a second flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0042] FIG5 shows a third flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0043] FIG6 shows a fourth flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0044] FIG7 shows one of the waveform diagrams of the control method of the energy storage converter in the embodiment of the present application;

[0045] FIG8 shows a second waveform diagram of the control method for the energy storage converter in an embodiment of the present application;

[0046] FIG9 shows a third waveform diagram of the control method for the energy storage converter in an embodiment of the present application;

[0047] FIG10 shows one of the closed-loop control flow charts of the energy storage converter in an embodiment of the present application;

[0048] FIG11 shows a fifth flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0049] FIG12 shows a second closed-loop control flow chart of the energy storage converter in an embodiment of the present application;

[0050] FIG13 shows a sixth flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0051] FIG14 shows a seventh flow chart of a control method for an energy storage converter in an embodiment of the present application;

[0052] FIG15 shows one of the structural block diagrams of the control device of the energy storage converter in the embodiment of the present application;

[0053] FIG16 shows a second structural block diagram of the control device of the energy storage converter in an embodiment of the present application;

[0054] 1 and 2 , the correspondence between the reference numerals and component names is as follows: 100 energy storage converter, 101 first port, 102 second port, 103 DC converter module, 104 first DC power supply, 105 first capacitor, 106 second capacitor, 107 first semiconductor component, 1071 first semiconductor device, 1072 second semiconductor device, 1073 third semiconductor device, 1074 fourth semiconductor device, 108 third capacitor, 109 inductor component, 110 fourth capacitor, 111 AC converter module, 112 branch resistor, 114 branch switch, 116 fifth semiconductor device, 118 sixth semiconductor device, 120 midpoint balancing branch. DETAILED DESCRIPTION

[0055] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0056] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0057] 1 to 16 , the energy storage converter and its control method, device, and readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0058] As shown in FIG1 , an embodiment of the present application provides an energy storage converter 100 for converting a DC power source into an AC power source. The energy storage converter 100 includes:

[0059] The first port 101 and the second port 102 are used to connect to a first DC power source 104;

[0060] The DC converter module 103 includes a first capacitor 105 and a second capacitor 106 , wherein one end of the first capacitor 105 is connected to the first port 101 , the other end of the first capacitor 105 is connected to one end of the second capacitor 106 , and the other end of the second capacitor 106 is connected to the second port 102 ;

[0061] The DC converter module 103 further includes a first semiconductor assembly 107, which includes a first semiconductor device 1071, a second semiconductor device 1072, a third semiconductor device 1073, and a fourth semiconductor device 1074. The first end of the first semiconductor device 1071 is connected to the first capacitor 105, the second end of the first semiconductor device 1071 is connected to the first end of the second semiconductor device 1072, the second end of the second semiconductor device 1072 is connected to the first end of the third semiconductor device 1073, the second end of the third semiconductor device 1073 is connected to the first end of the fourth semiconductor device 1074, and the second end of the fourth semiconductor device 1074 is connected to the second capacitor 106.

[0062] The DC converter module 103 further includes a third capacitor 108 , one end of the third capacitor 108 is connected to the second end of the first semiconductor device 1071 , and the other end of the third capacitor 108 is connected to the second end of the third semiconductor device 1073 ;

[0063] The DC converter module 103 further includes an inductor component 109 , one end of the inductor component 109 is connected to the second end of the second semiconductor device 1072 ;

[0064] The DC converter module 103 further includes a fourth capacitor 110 , one end of the fourth capacitor 110 is connected to the other end of the inductor component 109 , and the other end of the fourth capacitor 110 is connected to the second port 102 ;

[0065] The DC converter module 103 further includes a midpoint balancing branch 120 , wherein a first end of the midpoint balancing branch 120 is connected to the other end of the first capacitor 105 , a second end of the midpoint balancing branch 120 is connected to one end of the third capacitor 108 , and a third end of the midpoint balancing branch 120 is connected to the other end of the third capacitor 108 ;

[0066] The energy storage converter 100 further includes an AC converter module 111, one end of the AC converter module 111 is connected to the other end of the inductor component 109, and the other end of the AC converter module is connected to the second port 102. The AC converter module is used to convert the DC power output by the DC converter module into AC power.

[0067] The first semiconductor element 107 is used to adjust the voltage value of the fourth capacitor 110 so that the voltage value of the fourth capacitor 110 is greater than the first preset value and less than the second preset value;

[0068] The first semiconductor component 107 is further configured to adjust the voltage value of the third capacitor 108 so that the voltage value of the third capacitor 108 is a third preset value;

[0069] The midpoint balancing branch 120 is used to adjust the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106 so that the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106 are equal to a fourth preset value.

[0070] In this embodiment, an energy storage converter 100 is provided for converting an input first DC power source 104 into an AC power source for output, wherein the first DC power source 104 is a power source that provides DC power.

[0071] The energy storage converter 100 includes a first port 101 and a second port 102 , which are used to be connected to a first DC power source 104 .

[0072] Exemplarily, the first port 101 may be connected to the positive electrode of the first DC power source 104 , and the second port 102 may be connected to the negative electrode of the first DC power source 104 .

[0073] The energy storage converter 100 also includes a DC converter module 103, including a first capacitor 105 and a second capacitor 106, one end of the first capacitor 105 is connected to the first port 101, the other end of the first capacitor 105 is connected to one end of the second capacitor 106, and the other end of the second capacitor 106 is connected to the second port 102; the first capacitor 105 and the second capacitor 106 are voltage-stabilizing capacitors used to achieve voltage balance of the energy storage converter 100.

[0074] The DC converter module 103 also includes a first semiconductor component 107, which includes a first semiconductor device 1071, a second semiconductor device 1072, a third semiconductor device 1073 and a fourth semiconductor device 1074. The first end of the first semiconductor device 1071 is connected to the first capacitor 105, the second end of the first semiconductor device 1071 is connected to the first end of the second semiconductor device 1072, the second end of the second semiconductor device 1072 is connected to the first end of the third semiconductor device 1073, the second end of the third semiconductor device 1073 is connected to the first end of the fourth semiconductor device 1074, and the second end of the fourth semiconductor device 1074 is connected to the second capacitor 106.

[0075] The first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 , and the fourth semiconductor device 1074 are specifically devices having semiconductor characteristics.

[0076] For example, the first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 , and the fourth semiconductor device 1074 may include IGBTs (Insulated Gate Bipolar Transistors).

[0077] It should be noted that the first semiconductor component 107 is a device that can be controlled to be on or off, and the state switching time of the first semiconductor component 107 is relatively fast, thereby ensuring the state switching speed of the energy storage converter 100 .

[0078] For example, the state switching time of the first semiconductor component 107 may be specifically 5 ms to 10 ms.

[0079] The DC converter module 103 also includes a third capacitor 108, one end of the third capacitor 108 is connected to the second end of the first semiconductor device 1071, and the other end of the third capacitor 108 is connected to the second end of the third semiconductor device 1073; wherein the third capacitor 108 is a voltage-stabilizing capacitor, which is used to achieve voltage balance of the energy storage converter 100.

[0080] For example, the third capacitor 108 can achieve voltage balance of the energy storage converter 100 together with the first capacitor 105 and the second capacitor 106 .

[0081] The DC converter module 103 further includes an inductor component 109 , one end of which is connected to the second end of the second semiconductor device 1072 , for storing electrical energy of the first DC power source 104 .

[0082] The DC converter module 103 further includes a fourth capacitor 110 . One end of the fourth capacitor 110 is connected to the other end of the inductor component 109 , and the other end of the fourth capacitor 110 is connected to the second port 102 .

[0083] Energy storage converter 100 also includes an AC converter module 111. One end of AC converter module 111 is connected to the other end of inductor assembly 109, and the other end of AC converter module 111 is connected to second port 102. AC converter module 111 is configured to convert the DC power output by DC converter module 103 into AC power. AC converter module 111 is configured to convert the DC power output by DC converter module 103 into AC power and output it.

[0084] Exemplarily, the AC converter module 111 may be an H-bridge circuit, an NPC circuit, or an ANPC circuit.

[0085] It should be noted that the first semiconductor component 107 is used to adjust the voltage value of the fourth capacitor 110 so that the voltage value of the fourth capacitor 110 is greater than the first preset value and less than the second preset value; thereby minimizing the current ripple of the inductor component 109, thereby avoiding the current ripple of the inductor component 109 being large and causing a decrease in the efficiency of the energy storage converter 100.

[0086] Furthermore, the first semiconductor component 107 is also used to adjust the voltage value of the third capacitor 108 so that the voltage value of the third capacitor 108 is a third preset value, thereby ensuring the stability of the voltage value during current transmission during the operation of the energy storage capacitor.

[0087] Furthermore, the midpoint balancing branch 120 is used to adjust the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106 so that the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106 are a fourth preset value to ensure stable operation of the energy storage converter 100.

[0088] The energy storage converter 100 in this embodiment, through the provision of a DC converter module, can adjust the voltage value of the fourth capacitor 110 during operation in situations with high DC voltage values ​​and low AC voltage values, thereby maintaining the voltage value of the fourth capacitor 110 between the first preset value and the second preset value, thereby minimizing the current ripple of the inductor component 109 and preventing large current ripple of the inductor component 109 from causing a decrease in the efficiency of the energy storage converter 100. At the same time, the midpoint balancing branch 120 adjusts the voltage values ​​of the first capacitor 105 and the second capacitor 106 to the fourth preset value to ensure the stability of the operation of the energy storage converter 100.

[0089] In some embodiments, optionally, an energy storage converter 100 is provided, wherein when half of the voltage value of the first DC power supply 104 is less than a first preset value, the first semiconductor component 107 is controlled to operate in a first mode so that the voltage value of the fourth capacitor 110 is greater than the first preset value;

[0090] In the first mode, the duty cycle of the first semiconductor device 1071 and the second semiconductor device 1072 is greater than 0.5, and the duty cycle of the third semiconductor device 1073 and the fourth semiconductor device 1074 is less than 0.5;

[0091] When half of the voltage value of the first DC power source 104 is greater than the second preset value, the first semiconductor component 107 is controlled to operate in the second mode so that the voltage value of the fourth capacitor 110 is less than the second preset value;

[0092] In the second mode, the duty ratios of the first semiconductor device 1071 and the second semiconductor device 1072 are less than 0.5, and the duty ratios of the third semiconductor device 1073 and the fourth semiconductor device 1074 are greater than 0.5;

[0093] When half of the voltage value of the first DC power source 104 is greater than the first preset value and less than the second preset value, the first semiconductor component 107 is controlled to operate in the third mode so that the voltage value of the fourth capacitor 110 is greater than the first preset value and less than the second preset value;

[0094] In the third mode, the duty ratio of the first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 , and the fourth semiconductor device 1074 is 0.5.

[0095] In this embodiment, when half of the voltage of the first DC power source 104 is less than the first preset value, the first semiconductor component 107 is controlled to operate in the first mode so that the voltage of the fourth capacitor 110 is greater than the first preset value.

[0096] Specifically, in the first mode, the duty ratios of the first semiconductor device 1071 and the second semiconductor device 1072 are greater than 0.5, and the duty ratios of the third semiconductor device 1073 and the fourth semiconductor device 1074 are less than 0.5.

[0097] When half of the voltage of the first DC power source 104 is greater than the second preset value, the first semiconductor device 107 is controlled to operate in the second mode, so that the voltage of the fourth capacitor 110 is less than the second preset value.

[0098] Specifically, in the second mode, the duty ratios of the first semiconductor device 1071 and the second semiconductor device 1072 are less than 0.5, and the duty ratios of the third semiconductor device 1073 and the fourth semiconductor device 1074 are greater than 0.5.

[0099] When half of the voltage of the first DC power supply 104 is greater than the first preset value and less than the second preset value, the first semiconductor component 107 is controlled to operate in the third mode so that the voltage of the fourth capacitor 110 is greater than the first preset value and less than the second preset value.

[0100] Specifically, in the third mode, the duty ratio of the first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 , and the fourth semiconductor device 1074 is 0.5.

[0101] It is understandable that when half of the voltage value of the first DC power supply 104 is less than the first preset value or greater than the second preset value, the voltage value of the fourth capacitor 110 will be too low or too high, thereby causing the current ripple of the inductor component 109 to be large, resulting in reduced efficiency of the energy storage converter 100. At this time, by adjusting the duty cycle of the first semiconductor device 1071, the second semiconductor device 1072, the third semiconductor device 1073, and the fourth semiconductor device 1074, the voltage value of the fourth capacitor 110 is adjusted so that the voltage value of the fourth capacitor 110 is maintained between the first preset value and the second preset value, thereby minimizing the current ripple of the inductor component 109, thereby avoiding large current ripple of the inductor component 109 and reducing the efficiency of the energy storage converter 100.

[0102] Accordingly, when half of the voltage value of the first DC power supply 104 is greater than the first preset value and less than the second preset value, the first semiconductor component 107 is controlled to operate in the third mode so that the voltage value of the fourth capacitor 110 is greater than the first preset value and less than the second preset value. This minimizes the current ripple of the inductor component 109 and prevents the current ripple of the inductor component 109 from being too large and causing a decrease in the efficiency of the energy storage converter 100.

[0103] In this embodiment, the first DC power supply 104 is compared with a first preset value and a second preset value, and the operating mode of the first semiconductor component 107 is controlled based on the comparison result, so that the voltage value of the fourth capacitor 110 is greater than the first preset value and less than the second preset value. This minimizes the current ripple of the inductor component 109 and prevents the current ripple of the inductor component 109 from being too large and causing a decrease in the efficiency of the energy storage converter 100.

[0104] In some embodiments, optionally, when the voltage value of the third capacitor 108 is greater than a third preset value and the average current value of the inductor component 109 is greater than 0, the on-time of the first semiconductor device 1071 and the third semiconductor device 1073 is reduced, and the on-time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is increased, so that the voltage value of the third capacitor 108 is equal to the third preset value;

[0105] When the voltage value of the third capacitor 108 is greater than the third preset value and the average current value of the inductor component 109 is less than 0, the on-time of the first semiconductor device 1071 and the third semiconductor device 1073 is increased, and the on-time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is reduced, so that the voltage value of the third capacitor 108 is equal to the third preset value;

[0106] When the voltage value of the third capacitor 108 is less than the third preset value and the average current value of the inductor component 109 is greater than 0, the on-time of the first semiconductor device 1071 and the third semiconductor device 1073 is increased, and the on-time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is reduced, so that the voltage value of the third capacitor 108 is equal to the third preset value;

[0107] When the voltage value of the third capacitor 108 is less than the third preset value and the average current value of the inductor component 109 is less than 0, the conduction time of the first semiconductor device 1071 and the third semiconductor device 1073 is reduced, and the conduction time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is increased, so that the voltage value of the third capacitor 108 is equal to the third preset value.

[0108] In this embodiment, when the voltage value of the third capacitor 108 is greater than the third preset value and the average current value of the inductor component 109 is greater than 0, the on-time of the first semiconductor device 1071 and the third semiconductor device 1073 is reduced, and the on-time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is increased, so that the voltage value of the third capacitor 108 is equal to the third preset value, and the on-time is the time during which the first semiconductor device 1071, the second semiconductor device 1072, the third semiconductor device 1073 or the fourth semiconductor device 1074 is in the on state.

[0109] When the voltage value of the third capacitor 108 is greater than the third preset value and the average current value of the inductor component 109 is less than 0, the conduction time of the first semiconductor device 1071 and the third semiconductor device 1073 is increased, and the conduction time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is reduced to make the voltage value of the third capacitor 108 equal to the third preset value.

[0110] When the voltage value of the third capacitor 108 is less than the third preset value and the average current value of the inductor component 109 is greater than 0, the conduction time of the first semiconductor device 1071 and the third semiconductor device 1073 is increased, and the conduction time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is reduced, so that the voltage value of the third capacitor 108 is equal to the third preset value.

[0111] When the voltage value of the third capacitor 108 is less than the third preset value and the average current value of the inductor component 109 is less than 0, the conduction time of the first semiconductor device 1071 and the third semiconductor device 1073 is reduced, and the conduction time of the second semiconductor device 1072 and the fourth semiconductor device 1074 is increased to make the voltage value of the third capacitor 108 equal to the third preset value.

[0112] The energy storage converter 100 in this embodiment adjusts the conduction time of the first semiconductor device 1071, the second semiconductor device 1072, the third semiconductor device 1073 and the fourth semiconductor device 1074 so that the voltage value of the third capacitor 108 is equal to the third preset value, thereby achieving voltage balance of the energy storage converter 100 and ensuring the safe operation of the energy storage converter 100.

[0113] In some embodiments, optionally, the first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 and the fourth semiconductor device 1074 each include an insulated gate transistor and a diode for controlling the current flow between the first port 101 and the second port 102 and the inductor component 109 .

[0114] In this embodiment, the first semiconductor device 1071, the second semiconductor device 1072, the third semiconductor device 1073 and the fourth semiconductor device 1074 each include an insulated gate transistor and a diode for controlling the current flow between the first port 101 and the second port 102 and the inductor component 109, wherein the diode and the insulated gate transistor are anti-parallel connected.

[0115] Exemplarily, the anode of the diode is connected to the source of the insulated gate transistor, and the cathode of the diode is connected to the drain of the insulated gate transistor.

[0116] The first semiconductor device 1071 , the second semiconductor device 1072 , the third semiconductor device 1073 and the fourth semiconductor device 1074 in the energy storage converter 100 in this embodiment each include an insulated gate transistor and a diode, thereby achieving voltage balance of the energy storage converter 100 and thereby ensuring safe operation of the energy storage converter 100 .

[0117] In some embodiments, as shown in FIG2 , optionally, the midpoint balancing branch 120 further includes:

[0118] a branch resistor 112 , one end of the branch resistor 112 being connected to the other end of the first capacitor 105 ;

[0119] A branch switch 114 , one end of the branch switch 114 being connected to the other end of the branch resistor 112 ;

[0120] a fifth semiconductor device 116 , wherein the positive electrode of the fifth semiconductor device 116 is connected to the other end of the branch switch 114 , and the negative electrode of the fifth semiconductor device 116 is connected to one end of the third capacitor 108 ;

[0121] a sixth semiconductor device 118 , wherein the positive electrode of the sixth semiconductor device 118 is connected to the other end of the third capacitor 108 , and the negative electrode of the sixth semiconductor device 118 is connected to the other end of the branch switch 114 ;

[0122] The branch switch 114 is used to control the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106 to be equal to half of the voltage value of the first DC power supply 104 .

[0123] In this embodiment, the midpoint balancing branch 120 includes a branch resistor 112 and a branch switch 114. The current in the branch resistor 112 can be switched on and off by turning the branch switch 114 on and off. Furthermore, the DC converter module 103 also includes a fifth semiconductor device 116, the positive electrode of which is connected to the other end of the branch switch 114 and the negative electrode of which is connected to one end of the third capacitor 108; and a sixth semiconductor device 118, the positive electrode of which is connected to the other end of the third capacitor 108 and the negative electrode of which is connected to the other end of the branch switch 114. The fifth and sixth semiconductor devices 116 and 118 are used to limit the direction of current flow in the branch resistor 112.

[0124] For example, each of the fifth semiconductor device 116 and the sixth semiconductor device 118 may be a diode.

[0125] The energy storage converter 100 in this embodiment controls the opening or closing of the branch switch 114, thereby connecting the branch resistor 112 to the first semiconductor component 107, thereby adjusting the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106, so that the voltage value of the first capacitor 105 is equal to the voltage value of the second capacitor 106, thereby achieving voltage balance of the energy storage converter 100 and ensuring the safe operation of the energy storage converter 100.

[0126] In some embodiments, optionally, when the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106 and the voltage value of the second capacitor 106 is less than the difference between the voltage value of the first DC power supply 104 and the voltage value of the third capacitor 108, the branch switch 114 is controlled to be closed, and the first semiconductor device 1071 is controlled to be turned on;

[0127] When the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106, and the voltage value of the first capacitor 105 is less than the difference between the voltage value of the first DC power supply 104 and the voltage value of the third capacitor 108, the branch switch 114 is controlled to be closed, and the fourth semiconductor device 1074 is controlled to be turned on.

[0128] In this embodiment, when the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106, and the voltage value of the second capacitor 106 is less than the difference between the voltage value of the first DC power supply 104 and the voltage value of the third capacitor 108, that is, when the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106, and the voltage value of the first capacitor 105 is greater than the voltage value of the second capacitor 106, the branch switch 114 is controlled to be closed so that the branch resistor 112 is connected to the first semiconductor component 107. Furthermore, after the branch switch 114 is closed, the first semiconductor device 1071 is controlled to be turned on, so that current flows from the first semiconductor component 107 to the branch resistor 112, thereby reducing the voltage value of the first capacitor 105 and increasing the voltage value of the second capacitor 106, so that the voltage value of the first capacitor 105 is equal to the voltage value of the second capacitor 106.

[0129] When the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106, and the voltage value of the first capacitor 105 is less than the difference between the voltage value of the first DC power supply 104 and the voltage value of the third capacitor 108, that is, when the voltage value of the first capacitor 105 is not equal to the voltage value of the second capacitor 106, and the voltage value of the first capacitor 105 is less than the voltage value of the second capacitor 106, the branch switch 114 is controlled to be closed so that the branch resistor 112 is connected to the first semiconductor component 107. Further, after the branch switch 114 is closed, the fourth semiconductor device 1074 is controlled to be turned on, so that current flows from the branch resistor 112 to the first semiconductor component 107, thereby increasing the voltage value of the first capacitor 105 and decreasing the voltage value of the second capacitor 106, so that the voltage value of the first capacitor 105 is equal to the voltage value of the second capacitor 106.

[0130] The energy storage converter 100 in this embodiment controls the opening or closing of the branch switch 114 and coordinates the conduction of the first semiconductor device 1071 and the fourth semiconductor device 1074, thereby connecting the branch resistor 112 to the first semiconductor component 107, and then adjusting the voltage value of the first capacitor 105 and the voltage value of the second capacitor 106, so that the voltage value of the first capacitor 105 is equal to the voltage value of the second capacitor 106, thereby achieving voltage balance of the energy storage converter 100 and ensuring the safe operation of the energy storage converter 100.

[0131] In some embodiments, optionally, each of the fifth semiconductor device 116 and the sixth semiconductor device 118 includes a diode for controlling the current flow between the branch resistor 112 and the third capacitor 108 .

[0132] As shown in FIG3 , an embodiment of the present application provides a control method for an energy storage converter, including:

[0133] Step 302, determining a first preset value according to a target output voltage value of the energy storage converter;

[0134] Step 304, determining a second preset value according to the operating parameters of the AC converter module;

[0135] Step 306 , controlling the first semiconductor device so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

[0136] In this embodiment, a control method for an energy storage converter is provided. The energy storage converter is the energy storage converter in any of the above embodiments. The energy storage converter is connected to a first DC power supply.

[0137] First, a target output voltage value of the energy storage current device is obtained, and a first preset value can be determined according to the target output voltage value.

[0138] For example, if the output is a three-phase three-wire system, the output voltage value is U ac1 , then the first preset value U dcmin for:

[0139] If the output is a three-phase four-wire system, the output voltage value is U ac2 , then the first preset value U dcmin for:

[0140] Among them, k is a compensation coefficient greater than 1, which is usually related to the device voltage drop, dead time, etc., and is generally around 1.02.

[0141] Furthermore, the first semiconductor component is controlled so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

[0142] Specifically, when half of the voltage value of the first DC power supply is less than the first preset value, the first semiconductor component is controlled to operate in the first mode so that the voltage value of the fourth capacitor is greater than the first preset value;

[0143] In the first mode, the duty ratios of the first semiconductor device and the second semiconductor device are greater than 0.5, and the duty ratios of the third semiconductor device and the fourth semiconductor device are less than 0.5.

[0144] Specifically, in the first mode, as shown in FIG10 , the voltage value U of the fourth capacitor can be set. c4 The reference value is U* c4 , reference value U* c4 and the sampled U c4 Subtract the difference and pass it through the voltage loop UPI(s) to get the reference value of the inductor current I L *. Reference value I L * and the sampled I L Subtract the difference and pass it through the current loop CPI(s) to get the duty cycle D. The waveform diagram of the DC converter module in the first mode is shown in Figure 7. Among them, S1 is the first semiconductor device, S2 is the second semiconductor device, S3 is the third semiconductor device, S4 is the fourth semiconductor device, U L1 is the voltage value of the inductor component, I L1 is the current of the inductive component.

[0145] When half of the voltage value of the first DC power supply is greater than the second preset value, the first semiconductor component is controlled to operate in the second mode so that the voltage value of the fourth capacitor is less than the second preset value.

[0146] In the second mode, the duty ratios of the first semiconductor device and the second semiconductor device are less than 0.5, and the duty ratios of the third semiconductor device and the fourth semiconductor device are greater than 0.5.

[0147] Specifically, in the second mode, as shown in FIG10 , the voltage value U of the fourth capacitor can be set to c4 The reference value is U* c4 , reference value U* c4 and the sampled U c4 Subtract the difference and pass it through the voltage loop UPI(s) to get the reference value of the inductor current I L *. Reference value I L * and the sampled I LSubtract, and the difference passes through the current loop CPI(s) to obtain the duty cycle D. The waveform schematic diagram of the DC converter module in the second mode is shown in Figure 8. Among them, S1 is the first semiconductor device, S2 is the second semiconductor device, S3 is the third semiconductor device, S4 is the fourth semiconductor device, U L1 is the voltage value of the inductor component, and I L1 is the current of the inductor component.

[0148] When half of the voltage value of the first DC power supply is greater than the first preset value and less than the second preset value, control the first semiconductor component to operate in the third mode so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value;

[0149] In the third mode, the duty cycles of the first semiconductor device, the second semiconductor device, the third semiconductor device, and the fourth semiconductor device are 0.5. The waveform schematic diagram of the DC converter module in the third mode is shown in Figure 9. Among them, S1 is the first semiconductor device, S2 is the second semiconductor device, S3 is the third semiconductor device, S4 is the fourth semiconductor device, U L1 is the voltage value of the inductor component, and I L1 is the current of the inductor component.

[0150] In this embodiment, by comparing the first DC power supply with the first preset value and the second preset value, and then controlling the operating mode of the first semiconductor component according to the comparison result, the voltage value of the fourth capacitor is made greater than the first preset value and less than the second preset value. This makes the current ripple of the inductor component the smallest and avoids the reduction of the efficiency of the energy storage converter due to the large current ripple of the inductor component.

[0151] In a specific embodiment, as shown in Figure 6, first, calculate the reference value of the voltage value U c4 of the fourth capacitor according to the required output AC voltage value as Udcmin. If U c4 is too high, the voltage value spikes at the device conduction or cutoff moments may cause device damage. Therefore, the AC converter module limits the maximum value of U c4 to Udcmax. This value is usually obtained based on experimental tests or empirical judgments.

[0152] Judge the relationship between the voltage value Ubat of the first DC power supply and Udcmax and Udcmin. If Udcmin < 0.5Ubat < Udcmax, the duty cycle is fixed at 0.5. Otherwise, if 0.5Ubat < Udcmin, the reference value U c4 of the voltage value U c4* is Udcmin, which makes the DC converter module perform closed-loop control in working mode 1; otherwise, if Udcmax<0.5Ubat, the capacitor C4 voltage value U can be set according to the overall efficiency of the converter. c4 The reference value enables the DC converter module to perform closed-loop control in working mode 2.

[0153] In some embodiments, optionally, as shown in FIG4 , a control method for an energy storage converter is provided, which controls the first semiconductor component so that the voltage value of the first capacitor, the voltage value of the second capacitor, and the voltage value of the sixth capacitor are equal, including:

[0154] Step 402, determining a first preset value according to a target output voltage value of the energy storage converter;

[0155] Step 404, determining a second preset value according to the operating parameters of the AC converter module;

[0156] Step 406, controlling the first semiconductor device so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value;

[0157] Step 408, obtaining the voltage value of the third capacitor;

[0158] Step 410 , controlling the first semiconductor device so that the voltage value of the third capacitor is a third preset value.

[0159] In this embodiment, the voltage value of the third capacitor may be obtained, and then the first semiconductor component may be controlled so that the voltage value of the third capacitor is a third preset value.

[0160] Specifically, when the voltage value of the third capacitor is greater than the third preset value and the average current of the inductor component is greater than 0, the on-time of the first semiconductor device and the third semiconductor device is reduced, and the on-time of the second semiconductor device and the fourth semiconductor device is increased, so that the voltage value of the third capacitor is equal to the third preset value;

[0161] When the voltage value of the third capacitor is greater than a third preset value and the average current value of the inductor component is greater than 0, increasing the on-time of the first semiconductor device and the third semiconductor device and reducing the on-time of the second semiconductor device and the fourth semiconductor device, so that the voltage value of the third capacitor is equal to the third preset value;

[0162] When the voltage value of the third capacitor is less than a third preset value and the average current value of the inductor component is greater than 0, increasing the on-time of the first semiconductor device and the third semiconductor device and reducing the on-time of the second semiconductor device and the fourth semiconductor device, so that the voltage value of the third capacitor is equal to the third preset value;

[0163] When the voltage value of the third capacitor is less than a third preset value and the average current value of the inductor component is greater than 0, reducing the on-time of the first semiconductor device and the third semiconductor device, and increasing the on-time of the second semiconductor device and the fourth semiconductor device, so that the voltage value of the third capacitor is equal to the third preset value;

[0164] The energy storage converter in this embodiment adjusts the conduction time of the first semiconductor device, the second semiconductor device, the third semiconductor device, and the fourth semiconductor device so that the voltage value of the third capacitor is a third preset value, thereby achieving voltage balance of the energy storage converter and ensuring the safe operation of the energy storage converter.

[0165] In a specific implementation, as shown in FIG11 , first obtain the voltage value U of the third capacitor C3. c3 , and set the reference value of the voltage value of C3, that is, the third preset value U c3 *. Then, judge U c3 with U c3 *. At the same time, determine the average current I Lave Is it greater than 0? c3 Greater than U c3 *andI Lave is greater than zero, the time during which the first semiconductor device and the third semiconductor device are simultaneously turned on is reduced, and the time during which S2 and S4 are simultaneously turned on is correspondingly increased; if U c3 Greater than U c3 *andI Lave is less than zero, the time during which the first semiconductor device and the third semiconductor device are simultaneously turned on is increased, and the time during which the second semiconductor device and the fourth semiconductor device are simultaneously turned on is correspondingly reduced; if U c3 Less than U c3 *andI Lave is greater than zero, the time during which the first semiconductor device and the third semiconductor device are simultaneously turned on is increased, and the time during which the second semiconductor device and the fourth semiconductor device are simultaneously turned on is correspondingly reduced; if U c3 Less than U c3 *andI Lave If the value is less than zero, the time during which the first semiconductor device and the third semiconductor device are simultaneously turned on is reduced, and the time during which the second semiconductor device and the fourth semiconductor device are simultaneously turned on is correspondingly increased.

[0166] Specifically, the time of decrease and increase ΔT can be obtained by closed-loop control, and the closed-loop control can adopt the structure shown in Figure 12. c3 * and the sampled U c3 Subtract the difference and divide it by the average value of the inductor current I Lave , and then pass through the balance ring BPI(s) to obtain △T.

[0167] In some embodiments, optionally, as shown in FIG5 , a control method for an energy storage converter is provided, including:

[0168] Step 502, determining a first preset value according to a target output voltage value of the energy storage converter;

[0169] Step 504, determining a second preset value according to the operating parameters of the AC converter module;

[0170] Step 506, controlling the first semiconductor device so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value;

[0171] Step 508, obtaining the voltage value of the third capacitor;

[0172] Step 510, controlling the first semiconductor device so that the voltage value of the third capacitor is a third preset value;

[0173] Step 512, obtaining the voltage value of the first capacitor and the voltage value of the second capacitor;

[0174] Step 514 : Control the midpoint balancing branch and the first semiconductor component of the energy storage converter to make the voltage value of the first capacitor and the voltage value of the second capacitor equal to a fourth preset value.

[0175] In this embodiment, the midpoint balancing branch and the first semiconductor component are controlled so that the voltage value of the first capacitor and the voltage value of the second capacitor are equal to the fourth preset value, that is, the voltage value of the first capacitor is equal to the voltage value of the second capacitor. Specifically, when the voltage value of the first capacitor and the voltage value of the second capacitor are not equal, and the voltage value of the second capacitor is less than the difference between the voltage value of the first DC power supply and the voltage value of the third capacitor, that is, when the voltage value of the first capacitor and the voltage value of the second capacitor are not equal, and the voltage value of the first capacitor is greater than the voltage value of the second capacitor. The branch switch of the midpoint balancing branch is controlled to be closed so that the branch resistor is connected to the first semiconductor component. Further, after the branch switch is closed, the first semiconductor device is controlled to be turned on, so that current flows from the first semiconductor component to the branch resistor, thereby reducing the voltage value of the first capacitor and increasing the voltage value of the second capacitor, so that the voltage value of the first capacitor is equal to the voltage value of the second capacitor.

[0176] When the voltage value of the first capacitor is not equal to the voltage value of the second capacitor, and the voltage value of the first capacitor is less than the difference between the voltage value of the first DC power supply and the voltage value of the third capacitor, that is, when the voltage value of the first capacitor is not equal to the voltage value of the second capacitor, and the voltage value of the first capacitor is less than the voltage value of the second capacitor, the branch switch of the midpoint balancing branch is controlled to be closed so that the branch resistor is connected to the first semiconductor component. Furthermore, after the branch switch is closed, the fourth semiconductor device is controlled to be turned on, so that current flows from the branch resistor to the first semiconductor component, thereby increasing the voltage value of the first capacitor and decreasing the voltage value of the second capacitor, so that the voltage value of the first capacitor is equal to the voltage value of the second capacitor.

[0177] The energy storage converter in this embodiment controls the opening or closing of the branch switch of the midpoint balancing branch, and at the same time cooperates with the conduction of the first semiconductor device and the fourth semiconductor device, thereby connecting the branch resistor to the first semiconductor component, and then adjusting the voltage value of the first capacitor and the voltage value of the second capacitor to make the voltage value of the first capacitor equal to the voltage value of the second capacitor, thereby achieving voltage balance of the energy storage converter and ensuring the safe operation of the energy storage converter.

[0178] In a specific embodiment, as shown in FIG13 , the voltage value U of the first capacitor can be set first. c1 The voltage deviation limit ΔUmax between the voltage of the second capacitor and the voltage value Uc2 is calculated. The absolute value of the difference between Uc1 and Uc2 is then calculated to determine its relationship with Umax. If |Uc1-Uc2| is greater than Umax, branch switch K1 is closed; otherwise, K1 is opened.

[0179] Furthermore, in order to avoid frequent actions of K1, the following method can be used to control K1, as shown in Figure 14:

[0180] First, set two threshold voltages, △Uth1 and △Uth2, with △Uth1 < △Uth2. Determine the state of K1. Calculate the absolute value of the difference between Uc1 and Uc2 and determine its relationship to △Uth1 and △Uth2. If K1 is closed and |Uc1-Uc2| is less than △Uth1, then disconnect K1. If K1 is closed and |Uc1-Uc2| is greater than △Uth1, then K1 remains closed. If K1 is disconnected and |Uc1-Uc2| is greater than △Uth2, then connect K1. If K1 is disconnected and |Uc1-Uc2| is less than △Uth2, then connect K1.

[0181] As shown in FIG15 , an embodiment of the present application provides a control device 1500 for an energy storage converter, including:

[0182] An acquisition module 1502 is configured to acquire a first preset value based on a target output voltage value of the energy storage converter; and determine a second preset value based on an operating parameter of the AC converter module;

[0183] The control module 1504 is configured to control the first semiconductor component so that the voltage value of the fourth capacitor is greater than a first preset value and less than a second preset value.

[0184] In this embodiment, a control device 1500 for an energy storage converter is provided. The energy storage converter is the energy storage converter in any of the above embodiments. The energy storage converter is connected to a first DC power supply.

[0185] The control device of the energy storage converter in this embodiment can adjust the voltage value of the fourth capacitor during operation in situations where the DC voltage value is high and the AC voltage value is low, so that the voltage value of the fourth capacitor remains between the first preset value and the second preset value, thereby minimizing the current ripple of the inductor component and avoiding the current ripple of the inductor component being large and causing the efficiency of the energy storage converter to be reduced.

[0186] In some embodiments, optionally, as shown in FIG16 , a control device 1600 for an energy storage converter is proposed. The control device 1600 includes a processor 1602 and a memory 1604. The memory 1604 stores a program or instruction that, when executed by the processor 1602, implements the steps of the energy storage converter control method described in any of the above technical solutions. Therefore, the control device 1600 for an energy storage converter has all the beneficial effects of the energy storage converter control method described in any of the above technical solutions, and will not be further elaborated here.

[0187] In some embodiments, optionally, a readable storage medium is provided on which a program is stored. When the program is executed by a processor, the control method of the energy storage converter in any of the above embodiments is implemented, thereby having all the beneficial technical effects of the control method of the energy storage converter in any of the above embodiments.

[0188] The methods may be implemented in a variety of different ways depending on the specific features and / or example applications. For example, the methods may be implemented through a combination of hardware, firmware, and / or software. For example, in a hardware implementation, the processor may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, electronic devices, other device units for performing the above functions, and / or combinations thereof.

[0189] A computer-readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium can be, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes: a portable computer floppy disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory card, a floppy disk, an encoding mechanical device (such as a punched card or a groove with a raised structure on which instructions are recorded), and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be understood as a transmission signal per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium, or electrical signals transmitted through wires.

[0190] It should be clarified that in the claims, specification and drawings of this application, the term "plurality" refers to two or more. Unless otherwise clearly defined, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the purpose of more conveniently describing this application and making the description process simpler, and is not intended to indicate or imply that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation. Therefore, these descriptions cannot be understood as limitations on this application. The terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood based on the specific circumstances of the above data.

[0191] In the claims, specification, and drawings of this application, the terms "one embodiment," "some embodiments," "a specific embodiment," and the like mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of this application. In the claims, specification, and drawings of this application, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0192] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An energy storage converter, wherein, for converting a DC power supply into an AC power supply, the energy storage converter includes: A first port and a second port for connecting to a first DC power supply; A DC converter module including a first capacitor and a second capacitor, one end of the first capacitor is connected to the first port, the other end of the first capacitor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the second port; The DC converter module further includes a first semiconductor assembly, the first semiconductor assembly includes a first semiconductor device, a second semiconductor device, a third semiconductor device, and a fourth semiconductor device, a first end of the first semiconductor device is connected to the first capacitor, a second end of the first semiconductor device is connected to a first end of the second semiconductor device, a second end of the second semiconductor device is connected to a first end of the third semiconductor device, a second end of the third semiconductor device is connected to a first end of the fourth semiconductor device, and a second end of the fourth semiconductor device is connected to the second capacitor; The DC converter module further includes a third capacitor, one end of the third capacitor is connected to the second end of the first semiconductor device, and the other end of the third capacitor is connected to the second end of the third semiconductor device; The DC converter module further includes an inductor assembly, one end of the inductor assembly is connected to the second end of the second semiconductor device; The DC converter module further includes a fourth capacitor, one end of the fourth capacitor is connected to the other end of the inductor assembly, and the other end of the fourth capacitor is connected to the second port; The DC converter module further includes a midpoint balance branch, a first end of the midpoint balance branch is connected to the other end of the first capacitor, a second end of the midpoint balance branch is connected to one end of the third capacitor, and a third end of the midpoint balance branch is connected to the other end of the third capacitor; An AC converter module, one end of the AC converter module is connected to the other end of the inductor assembly, the other end of the AC converter module is connected to the second port, and the AC converter module is used to convert the DC power output by the DC converter module into AC power; The first semiconductor assembly is used to adjust the voltage value of the fourth capacitor so that the voltage value of the fourth capacitor is greater than a first preset value and less than a second preset value; The first semiconductor assembly is further used to adjust the voltage value of the third capacitor so that the voltage value of the third capacitor is a third preset value; The midpoint balance branch is used to adjust the voltage values of the first capacitor and the second capacitor so that the voltage values of the first capacitor and the second capacitor are a fourth preset value.

2. The energy storage converter according to claim 1, wherein, When half of the voltage value of the first DC power supply is less than the first preset value, control the first semiconductor assembly to operate in a first mode so that the voltage value of the fourth capacitor is greater than the first preset value; In the first mode, the duty cycles of the first semiconductor device and the second semiconductor device are greater than 0.5, and the duty cycles of the third semiconductor device and the fourth semiconductor device are less than 0.5; When half of the voltage value of the first DC power supply is greater than the second preset value, control the first semiconductor assembly to operate in the second mode so that the voltage value of the fourth capacitor is less than the second preset value; In the second mode, the duty cycles of the first semiconductor device and the second semiconductor device are less than 0.5, and the duty cycles of the third semiconductor device and the fourth semiconductor device are greater than 0.5; When half of the voltage value of the first DC power supply is greater than the first preset value and less than the second preset value, control the first semiconductor assembly to operate in the third mode so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value; In the third mode, the duty cycles of the first semiconductor device, the second semiconductor device, the third semiconductor device, and the fourth semiconductor device are 0.

5.

3. The energy storage inverter according to claim 1, wherein, When the voltage value of the third capacitor is greater than the third preset value and the average value of the current of the inductor assembly is greater than 0, reduce the conduction duration of the first semiconductor device and the third semiconductor device, and increase the conduction duration of the second semiconductor device and the fourth semiconductor device so that the voltage value of the third capacitor is equal to the third preset value; When the voltage value of the third capacitor is greater than the third preset value and the average value of the current of the inductor assembly is less than 0, increase the conduction duration of the first semiconductor device and the third semiconductor device, and reduce the conduction duration of the second semiconductor device and the fourth semiconductor device so that the voltage value of the third capacitor is equal to the third preset value; When the voltage value of the third capacitor is less than the third preset value and the average value of the current of the inductor assembly is greater than 0, increase the conduction duration of the first semiconductor device and the third semiconductor device, and reduce the conduction duration of the second semiconductor device and the fourth semiconductor device so that the voltage value of the third capacitor is equal to the third preset value; When the voltage value of the third capacitor is less than the third preset value and the average value of the current of the inductor assembly is less than 0, reduce the conduction duration of the first semiconductor device and the third semiconductor device, and increase the conduction duration of the second semiconductor device and the fourth semiconductor device so that the voltage value of the third capacitor is equal to the third preset value.

4. The energy storage inverter according to claim 1, wherein, The first semiconductor device, the second semiconductor device, the third semiconductor device, and the fourth semiconductor device each include an insulated gate transistor and a diode for controlling the current flow between the first port and the second port and the inductor assembly.

5. The energy storage inverter according to claim 1, wherein, The midpoint balancing branch includes: Branch resistor, one end of the branch resistor is connected to the other end of the first capacitor; Branch switch, one end of the branch switch is connected to the other end of the branch resistor; Fifth semiconductor device, the positive electrode of the fifth semiconductor device is connected to the other end of the branch switch, and the negative electrode of the fifth semiconductor device is connected to one end of the third capacitor; Sixth semiconductor device, the positive electrode of the sixth semiconductor device is connected to the other end of the third capacitor, and the negative electrode of the sixth semiconductor device is connected to the other end of the branch switch; The branch switch is used to control the voltage values of the first capacitor and the second capacitor to be equal to one half of the voltage value of the first DC power supply.

6. The energy storage converter according to claim 5, wherein, When the voltage values of the first capacitor and the second capacitor are not equal, and the voltage value of the second capacitor is less than the difference between the voltage value of the first DC power supply and the voltage value of the third capacitor, control the branch switch to close and control the first semiconductor device to conduct; When the voltage values of the first capacitor and the second capacitor are not equal, and the voltage value of the first capacitor is less than the difference between the voltage value of the first DC power supply and the voltage value of the third capacitor, control the branch switch to close and control the fourth semiconductor device to conduct.

7. The energy storage converter according to claim 5, wherein, Both the fifth semiconductor device and the sixth semiconductor device include a diode for controlling the current flow direction between the branch resistor and the third capacitor.

8. A control method for an energy storage converter, wherein, The energy storage converter is the energy storage converter according to any one of claims 1 to 7, the energy storage converter is connected to the first DC power supply, and the control method of the energy storage converter includes: Determine the first preset value according to the target output voltage value of the energy storage converter; Determine the second preset value according to the operating parameters of the AC converter module; Control the first semiconductor component so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

9. The control method for an energy storage converter according to claim 8, wherein, The control method of the energy storage converter further includes: Obtain the voltage value of the third capacitor; Control the first semiconductor component so that the voltage value of the third capacitor is the third preset value.

10. The control method for an energy storage converter according to claim 8, wherein, The control method of the energy storage converter further includes: Obtain the voltage values of the first capacitor and the second capacitor; Control the midpoint balance branch of the energy storage converter and the first semiconductor component so that the voltage values of the first capacitor and the second capacitor are equal to the fourth preset value.

11. A control device for an energy storage converter, wherein, The energy storage converter is the energy storage converter according to any one of claims 1 to 7, the energy storage converter is connected to the first DC power supply, and the control device of the energy storage converter includes: An acquisition module, configured to acquire the first preset value according to the target output voltage value of the energy storage converter; and determine the second preset value according to the operating parameters of the AC converter module; A control module, configured to control the first semiconductor component so that the voltage value of the fourth capacitor is greater than the first preset value and less than the second preset value.

12. A control device for an energy storage converter, wherein, comprises: a processor; a memory, in which a program or instruction is stored, and when the processor executes the program or instruction in the memory, the steps of the control method of the energy storage converter according to any one of claims 8 to 10 are implemented.

13. A readable storage medium, wherein, a program or instruction is stored on the readable storage medium, and when the program or instruction is executed by a processor, the steps of the control method of the energy storage converter according to any one of claims 8 to 10 are implemented.

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