Flying capacitor converter, voltage converter and energy storage system thereof

Abstract

The invention relates to a flying capacitor converter, a voltage converter and an energy storage system thereof, a high-voltage side is electrically connected to a first power supply, a low-voltage side is electrically connected to a second power supply, a common node is arranged between a low-voltage negative end of the low-voltage side and a high-voltage negative end of the high-voltage side, and a power switch assembly is electrically connected between the high-voltage side and the low-voltage side. The current switch assembly comprises a first end, a second end and a third end and comprises four power switches which are sequentially connected between the first end and the third end in series, the current switch assembly is electrically connected to the high-voltage side, the low-voltage side and / or the common node, and the current detection assembly is electrically connected between the third end of the power switch assembly and the common node. The controller controls the operation of the current switch assembly when the current detection assembly detects that the current condition is short circuit so as to disconnect the connection between the power switch assembly and the high-voltage side and / or the low-voltage side.

Description

Technical Field

[0001] This case involves a converter, in particular a flying capacitor converter, a voltage converter and an energy storage system thereof. Background Art

[0002] Compared with the traditional non-isolated two-level DC converter, the multi-level DC converter can use power devices with lower withstand voltage, and its filter components are smaller in size. Compared with other multi-level circuit topologies, the flying capacitor multi-level converter has a common negative electrode at the input and output ends, which is suitable for connecting multiple flying capacitor converters in parallel to increase the output power. Therefore, it has outstanding advantages in energy storage systems or rail transit systems.

[0003] In actual applications, multiple flying capacitor converters are connected to the DC common bus to charge and discharge multiple energy storage elements. When one of the flying capacitor converters is short-circuited, the other flying capacitor converters will provide short-circuit current to the short-circuit point. Due to the large number of flying capacitor converters, a large short-circuit current will be formed, which can easily cause overcurrent and overheating damage to electronic devices. Therefore, if the short-circuit current cannot be detected and eliminated in time, it will cause a larger short-circuit accident or even a fire.

[0004] Therefore, how to develop a flying capacitor converter, a voltage converter and an energy storage system thereof that overcome the above-mentioned disadvantages is an urgent need at present. Summary of the invention

[0005] The purpose of this case is to provide a flying capacitor converter, a voltage converter and an energy storage system thereof. The flying capacitor converter includes a current detection component and a controller. When the current detection component detects that the current condition of the common node of the flying capacitor converter is short-circuited, the controller controls the operation of the current switch component to disconnect the connection between the power switch component and the high-voltage side and / or the low-voltage side. Therefore, the flying capacitor converter of this case can trigger a protection action when a short-circuit fault occurs, so a large short-circuit current will not be formed, making the overall energy storage system safer. In addition, the current flowing through the common node in the flying capacitor converter of the energy storage system of this case is small, so that the current detection component that detects the current flowing through the common node can use a smaller component, thereby reducing the volume of the current detection component and reducing its cost. The current switch component connected in series to the common node can also use a smaller component, thereby reducing the volume of the current switch component, reducing costs, reducing losses, improving the efficiency of the overall energy storage system, and making it easier to heat dissipate. Furthermore, when the current condition of the high voltage side and / or the low voltage side of the flying capacitor converter is short circuit, one or more discharge currents generated by the first power source, the second power source, the first capacitor, the second capacitor and / or the third capacitor will all flow through the common node and can be quickly detected by the current detection component to improve the short circuit detection speed of the flying capacitor converter.

[0006] To achieve the above-mentioned purpose, a preferred embodiment of the present case is to provide a flying capacitor converter, which is electrically connected between a first power supply and a second power supply. The flying capacitor converter includes a high voltage side, a low voltage side, a common node, a power switch component, at least one current switch component, a current detection component and a controller. The high voltage side is electrically connected to the first power supply and includes a high voltage positive terminal and a high voltage negative terminal. The low voltage side is electrically connected to the second power supply and includes a low voltage positive terminal and a low voltage negative terminal. The common node is located between the low voltage negative terminal of the low voltage side and the high voltage negative terminal of the high voltage side. The power switch component is electrically connected between the high voltage side and the low voltage side, and includes a first end, a second end and a third end, and includes a first power switch, a second power switch, a third power switch and a fourth power switch connected in series in sequence between the first end and the third end of the power switch component. The current switch component is electrically connected to the high voltage side, the low voltage side and / or the common node. The current detection component is electrically connected between the third end of the power switch component and the common node to detect the current condition of the flying capacitor converter. The controller is electrically connected to the current detection component and at least one current switch component. When the current detection component detects that the current is short-circuited, the controller controls the operation of at least one current switch component to disconnect the connection between the power switch component and the high voltage side and / or the connection between the power switch component and the low voltage side.

[0007] To achieve the above-mentioned purpose, another preferred embodiment of the present case is to provide a flying capacitor converter, which is electrically connected between a first power supply and a second power supply. The flying capacitor converter includes a high voltage side, a low voltage side, a power switch component, a single current switch component, at least one current detection component and a controller. The high voltage side is electrically connected to the first power supply and includes a high voltage positive terminal and a high voltage negative terminal. The low voltage side is electrically connected to the second power supply and includes a low voltage positive terminal and a low voltage negative terminal, wherein a common node is provided between the low voltage negative terminal of the low voltage side and the high voltage negative terminal of the high voltage side. The power switch component is electrically connected between the high voltage side and the low voltage side and includes a first terminal, a second terminal and a third terminal, and includes a first power switch, a second power switch, a third power switch and a fourth power switch connected in series in sequence between the first terminal and the third terminal of the power switch component. The current switch component is electrically connected between the third terminal of the power switch component and the common node. At least one current detection component is electrically connected to the high voltage side, the low voltage side and / or the common node to detect the current condition of the flying capacitor converter. The controller is electrically connected to the current detection component and the current switch component. When the current detection component detects that the current is short-circuited, the controller controls the operation of the current switch component to disconnect the connection between the power switch component and the high voltage side and / or the connection between the power switch component and the low voltage side.

[0008] To achieve the above-mentioned purpose, another preferred embodiment of the present invention is to provide a voltage converter, comprising a high voltage side, a low voltage side, a power switch component, at least one current switch component and a current detection component. The high voltage side and the low voltage side are electrically connected to a common node. The power switch component is electrically connected between the high voltage side, the low voltage side and the common node. At least one current switch component is arranged in at least one power circuit of the voltage converter. The current detection component is arranged between the power switch component and the common node, and is used to detect the current condition of the common node.

[0009] To achieve the above-mentioned purpose, another preferred embodiment of the present case is to provide a voltage converter, comprising a high voltage side, a low voltage side, a power switch component, a current switch component, a high voltage side current detection component, a low voltage side current detection component and a controller. The high voltage side and the low voltage side are electrically connected to a common node. The power switch component is electrically connected between the high voltage side, the low voltage side and the common node. The current switch component is arranged between the power switch component and the common node. The high voltage side current detection component is electrically connected to the high voltage side, and is configured to detect the current condition of the high voltage side. The low voltage side current detection component is electrically connected to the low voltage side, and is configured to detect the current condition of the low voltage side. The controller electrically connects the current switch component, the high voltage side current detection component and the low voltage side current detection component. When the current condition of the high voltage side and / or the current condition of the low voltage side is detected to be a short circuit, the controller controls the current switch component to disconnect the connection between the power switch component and the high voltage side and the connection between the power switch component and the low voltage side.

[0010] To achieve the above-mentioned purpose, another preferred embodiment of the present invention is to provide an energy storage system, comprising at least one flying capacitor converter, a power supply and an energy storage element. The power supply is electrically connected to the high voltage side of the flying capacitor converter. The energy storage element is electrically connected to the low voltage side of the flying capacitor converter.

[0011] To achieve the above purpose, another preferred embodiment of the present invention is to provide an energy storage system, comprising at least one voltage converter, a power supply and an energy storage element. The power supply is electrically connected to the high voltage side of the voltage converter. The energy storage element is electrically connected to the low voltage side of the voltage converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A circuit topology diagram of the energy storage system of the first embodiment of the present invention;

[0013] Figure 2 A circuit topology diagram of the energy storage system of the second embodiment of the present invention;

[0014] Figure 3 A circuit topology diagram of the energy storage system of the third embodiment of the present invention;

[0015] Figure 4 A circuit topology diagram of the energy storage system of the fourth embodiment of the present invention; and

[0016] Figure 5 This is a circuit topology diagram of the energy storage system of the fifth embodiment of the present case.

[0017] The reference numerals are described as follows:

[0018] 1.1a,1b: Flying capacitor converter

[0019] 1c, 1d: Voltage converter

[0020] 11: High-voltage side

[0021] 111: High voltage positive terminal

[0022] 112: High voltage negative terminal

[0023] 12: Low pressure side

[0024] 121: Low voltage positive terminal

[0025] 122: Low voltage negative terminal

[0026] d: public node

[0027] 13: Power switch components

[0028] 131: First End

[0029] 132: Second End

[0030] 133: The Third End

[0031] S1: First power switch

[0032] S2: Second power switch

[0033] S3: The third power switch

[0034] S4: The fourth power switch

[0035] A: First connection point

[0036] B: Second connection point

[0037] C: Third connection point

[0038] L1: Inductor

[0039] 151: First current switch component

[0040] S5: First current switch

[0041] S6: Second current switch

[0042] 152: Second current switch component

[0043] S7: Third current switch

[0044] S8: Fourth current switch

[0045] 153: The third current switch component

[0046] S9: Fifth current switch

[0047] S10: Sixth current switch

[0048] C1: First capacitor

[0049] C2: Second capacitor

[0050] C3: The third capacitor

[0051] 16: Current detection component

[0052] 161: First current detection component

[0053] 162: Second current detection component

[0054] 163: The third current detection component

[0055] 17: Controller

[0056] K1: First mechanical switch

[0057] K2: Second mechanical switch

[0058] K3: Third mechanical switch

[0059] K4: Fourth mechanical switch

[0060] 2: First Power Supply

[0061] 3: Second power supply

[0062] 4, 4a, 4b, 4c, 4d: Energy storage system

[0063] S11: Fifth power switch

[0064] S12: Sixth power switch

[0065] S13: Seventh power switch

[0066] S14: The eighth power switch

[0067] C4: The fourth capacitor

[0068] 14: Common negative terminal DETAILED DESCRIPTION

[0069] Some typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different aspects without departing from the scope of the present invention, and the descriptions and drawings are essentially for illustrative purposes rather than for limiting the present invention.

[0070] For example, although the words "first", "second", "third", etc. may be used in the claims to describe different components, these components should not be limited by these terms, and these components described accordingly in the embodiments are represented by different component symbols. These terms are intended to distinguish different components. For example: the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component without departing from the scope of the embodiments. The term "and / or" used in this way includes any or all combinations of one or more related listed items. In addition, when a component is referred to as "connected to" or "coupled to" another component, it may be directly connected to or coupled to the other component, or there may be an intervening component.

[0071] See also Figure 1 , which is a circuit topology diagram of the energy storage system of the first embodiment of this case. Figure 1 As shown, the energy storage system 4 of this embodiment includes a flying capacitor converter 1, a first power source 2 and a second power source 3. The first power source 2 can be, but is not limited to, a DC power grid or a DC common bus, and the second power source 3 can be, but is not limited to, an energy storage element, such as a battery or a super capacitor. The flying capacitor converter 1 is electrically connected between the first power source 2 and the second power source 3 to perform power conversion and voltage conversion, and the flying capacitor converter 1 includes a high voltage side 11, a low voltage side 12, a common node d, a power switch component 13, at least one current switch component, a current detection component 16 and a controller 17.

[0072] The high voltage side 11 is electrically connected to the first power source 2, and includes a high voltage positive terminal 111 and a high voltage negative terminal 112, that is, the first power source 2 is electrically connected between the high voltage positive terminal 111 and the high voltage negative terminal 112 of the high voltage side 11. The low voltage side 12 is electrically connected to the second power source 3, and includes a low voltage positive terminal 121 and a low voltage negative terminal 122, that is, the second power source 3 is electrically connected between the low voltage positive terminal 121 and the low voltage negative terminal 122 of the low voltage side 12. The common node d is located between the low voltage negative terminal 122 of the low voltage side 12 and the high voltage negative terminal 112 of the high voltage side 11.

[0073] The power switch assembly 13 is electrically connected between the high voltage side 11 and the low voltage side 12, and includes a first end 131, a second end 132, a third end 133 and a plurality of power switches. In this embodiment, the plurality of power switches include, for example, a first power switch S1, a second power switch S2, a third power switch S3 and a fourth power switch S4. The first power switch S1, the second power switch S2, the third power switch S3 and the fourth power switch S4 are sequentially connected in series between the first end 131 and the third end 133, wherein the connection between the first power switch S1 and the second power switch S2 constitutes a first connection point A, the connection between the second power switch S2 and the third power switch S3 constitutes a second connection point B, and the connection between the third power switch S3 and the fourth power switch S4 constitutes a third connection point C.

[0074] In a specific embodiment, if Figure 1 As shown, the power switch component 13 of the flying capacitor converter 1 also includes a plurality of capacitors, for example, a first capacitor C1, a second capacitor C2, a third capacitor C3 and an inductor L1. The first capacitor C1 is electrically connected between the first end 131 and the third end 133 of the power switch component 13. The second capacitor C2 is a flying capacitor and is electrically connected between the first connection point A and the third connection point C. The third capacitor C3 is electrically connected between the second end 132 and the third end 133 of the power switch component 13. The inductor L1 is electrically connected between the second connection point B and the second end 132 of the power switch component 13, so that a flying capacitor three-level converter can be formed. Of course, it can be understood that in other embodiments, the circuit of the flying capacitor converter can also include multiple other power switch components to form other multi-level circuit topologies known to those skilled in the art, such as a flying capacitor four-level converter, which is not intended to limit the present invention.

[0075] In this embodiment, the current detection component 16 is electrically connected between the third end 133 of the power switch component 13 and the common node d to detect the current condition of the flying capacitor converter 1. In other words, the current detection component 16 confirms the current condition of the flying capacitor converter 1 by detecting the current flowing through the common node d. For example, the current detection component 16 can detect the current flowing through the common node d to confirm that the current condition of the high-voltage side 11 and / or the low-voltage side 12 of the flying capacitor converter 1 is short-circuited.

[0076] In a specific embodiment, if Figure 1As shown, the flying capacitor converter 1 includes, for example, a plurality of current switch components, which are arranged in a plurality of power circuits of the flying capacitor converter 1. The plurality of current switch components include, for example, a first current switch component 151 and a second current switch component 152. The first current switch component 151 is arranged in the power circuit between the high voltage side 11 and the power switch component 13, and specifically, the first current switch component 151 is electrically connected between the high voltage positive terminal 111 of the high voltage side 11 and the first terminal 131 of the power switch component 13. When the current detection component 16 detects that the current condition of the flying capacitor converter 1 is short-circuited, the connection between the power switch component 13 and the high voltage side 11 can be disconnected by the first current switch component 151. The second current switch component 152 is arranged in the power circuit between the low voltage side 12 and the power switch component 13, and specifically, the second current switch component 152 is electrically connected between the low voltage negative terminal 122 of the low voltage side 12 and the common node d. When the current detection component 16 detects that the current condition of the flying capacitor converter 1 is short-circuited, the connection between the power switch component 13 and the low-voltage side 12 can be disconnected by the second current switch component 152. In some embodiments, the first current switch component 151, for example, includes a first current switch S5 and a second current switch S6, wherein the first current switch S5 and the second current switch S6 are connected in reverse series to respectively transmit the current flowing out of the high-voltage side 11 and the current flowing into the high-voltage side 11. The second current switch component 152, for example, includes a third current switch S7 and a fourth current switch S8, wherein the third current switch S7 and the fourth current switch S8 are connected in reverse series to respectively transmit the current flowing into the low-voltage side 12 and the current flowing out of the low-voltage side 12. In some other embodiments, the first current switch component 151 and the second current switch component 152 may only include a single current switch to save the configuration cost of the current switch.

[0077] Of course, in some specific embodiments, for example, if a short circuit fault does not occur or has a very low probability of occurring on either the high voltage side 11 or the low voltage side 12 of the flying capacitor converter 1, the flying capacitor converter 1 may include only one of the first current switch component 151 and the second current switch component 152 to save the cost of setting the current switch. Figure 1 The first current switch S5, the second current switch S6, the third current switch S7 and the fourth current switch S8 are, for example, composed of a controllable switch and a diode. The controller 17 is electrically connected to the first current switch S5, the second current switch S6, the third current switch S7 and the fourth current switch S8 respectively. When the driving signal applied by the controller 17 to the above current switch is at a high level, the current switch is in an on state; when the driving signal applied by the controller 17 to the above current switch is at a low level, the current switch is in an off state.

[0078] It can be understood that the setting positions of the first current switch component 151 and the second current switch component 152 can be changed according to actual needs. For example, the first current switch component 151 can be electrically connected between the high-voltage negative terminal 112 of the high-voltage side 11 and the common node d, and the second current switch component 152 can also be electrically connected between the low-voltage positive terminal 121 of the low-voltage side 12 and the second end 132 of the power switch component 13. The present invention does not limit this.

[0079] The controller 17 is electrically connected to the current detection component 16, the first current switch component 151 and the second current switch component 152. When the current detection component 16 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited, the controller 17 controls the actions of all current switch components in the flying capacitor converter 1, thereby correspondingly disconnecting the connection between the power switch component 13 and the high voltage side 11 and / or the low voltage side 12. Specifically, for example, when the flying capacitor converter 1 only includes the first current switch component 151, and the controller 17 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited when the current detection component 16 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited, the first current switch component 151 is controlled to be closed to disconnect the connection between the power switch component 13 and the high voltage side 11; when the flying capacitor converter 1 only includes the second current switch component 152, and the controller 17 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited when the current detection component 16 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited. When the flying capacitor converter 1 includes a first current switch component 151 and a second current switch component 152, and the controller 17 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited in the current detection component 16, the first current switch component 151 and the second current switch component 152 are controlled to be closed to disconnect the power switch component 13 from the high voltage side 11 and the low voltage side 12.

[0080] As can be seen from the above, the flying capacitor converter 1 of the energy storage system 4 of the present case includes a current detection component 16 and a controller 17, and the current detection component 16 is electrically connected between the third end 133 of the power switch component 13 and the common node d. When the current detection component 16 detects that the current condition of the common node d of the flying capacitor converter 1 is short-circuited, the controller 17 controls the operation of the first current switch component 151 and / or the second current switch component 152 to correspondingly disconnect the connection between the power switch component 13 and the high-voltage side 11 and / or the low-voltage side 12. Therefore, the flying capacitor converter 1 of the present case can trigger a protection action when a short-circuit fault occurs, so that a large short-circuit current will not be formed, so that the safety of the overall energy storage system 4 is higher. In addition, according to Figure 1From the circuit topology, it can be seen that the current flowing through the common node d is the difference between the current flowing through the low-voltage side 12 and the current flowing through the high-voltage side 11, so the current flowing through the common node d is less than the current flowing through the low-voltage side 12. And when the voltage on the high-voltage side 11 is greater than half of the voltage on the low-voltage side 12, the current flowing through the common node d is also less than the current flowing through the high-voltage side 11. In other words, the current flowing through the common node d in the flying capacitor converter 1 of the energy storage system 4 of this case is small, so that the current detection component 16 for detecting the current flowing through the common node d can use smaller components, thereby reducing the volume of the current detection component 16 and reducing its cost. The current switch component connected in series to the common node d can also use smaller components, thereby reducing the volume of the current switch component, reducing costs, reducing losses, improving the efficiency of the overall energy storage system 4, and making it easier to perform heat dissipation. Furthermore, when the current condition of the high voltage side 11 and / or the low voltage side 12 of the flying capacitor converter 1 is short-circuited, one or more discharge currents generated by the first power source 2, the second power source 3, the first capacitor C1, the second capacitor C2 and / or the third capacitor C3 will all flow through the common node d and can be quickly detected by the current detection component 16 to improve the short circuit detection speed of the flying capacitor converter 1.

[0081] Please continue reading Figure 1 In a specific embodiment, the flying capacitor converter 1 may further include four mechanical switches, namely a first mechanical switch K1, a second mechanical switch K2, a third mechanical switch K3 and a fourth mechanical switch K4, so that the flying capacitor converter 1 can use the opening or closing of the mechanical switch to achieve active control of the connection between the high voltage side 11 and the power switch component 13 and / or the connection between the low voltage side 12 and the power switch component 13. The first mechanical switch K1 is electrically connected between the high voltage positive terminal 111 of the high voltage side 11 and the first current switch component 151. The second mechanical switch K2 is electrically connected between the high voltage negative terminal 112 of the high voltage side 11 and the common node d. The third mechanical switch K3 is electrically connected between the low voltage positive terminal 121 of the low voltage side 12 and the second terminal 132 of the power switch component 13. The fourth mechanical switch K4 is electrically connected between the low voltage negative terminal 122 of the low voltage side 12 and the second current switch component 152. In some embodiments, the flying capacitor converter may include only at least one mechanical switch among the first mechanical switch K1 , the second mechanical switch K2 , the third mechanical switch K3 and the fourth mechanical switch K4 , such as a single mechanical switch or two mechanical switches, to save configuration cost.

[0082] See also Figure 2 , which is a circuit topology diagram of the energy storage system of the second embodiment of this case. Figure 2 As shown, compared to Figure 1The flying capacitor converter 1 shown includes two current switch components, and the flying capacitor converter 1a of the present embodiment includes only a single current switch component, namely, the third current switch component 153. The third current switch component 153 is arranged in the power loop between the power switch component 13 and the common node d, and specifically, the third current switch component 153 is electrically connected between the third end 133 of the power switch component 13 and the common node d. In some embodiments, the third current switch component 153, for example, includes a fifth current switch S9 and a sixth current switch S10, wherein the fifth current switch S9 and the sixth current switch S10 are connected in reverse series to respectively transmit the current flowing into the power switch component 13 and the current flowing out of the power switch component 13. In some other embodiments, the third current switch component 153 may include only a single current switch to save the cost of setting up the current switch. Please continue to refer to Figure 2 The fifth current switch S9 and the sixth current switch S10 are, for example, composed of a controllable switch and a diode. The controller 17 is electrically connected to the fifth current switch S9 and the sixth current switch S10, respectively. When the driving signal applied by the controller 17 to the above current switches is at a high level, the current switches are in an on state; when the driving signal applied by the controller 17 to the above current switches is at a low level, the current switches are in an off state.

[0083] Compared to Figure 1 The current detection component 16 of the flying capacitor converter 1 of the energy storage system 4 shown is electrically connected between the third terminal 133 of the power switch component 13 and the common node d. The current detection component of the flying capacitor converter 1a of the energy storage system 4a of the second embodiment can be electrically connected to the high voltage side 11, the low voltage side 12 and / or the common node d of the flying capacitor converter 1a; Figure 2As shown, the flying capacitor converter 1a includes, for example, a first current detection component 161, a second current detection component 162, and a third current detection component 163. The first current detection component 161 is disposed on the high voltage side 11 to detect the short circuit condition of the high voltage side 11, and therefore can also be referred to as a high voltage side current detection component. Specifically, the first current detection component 161 is electrically connected between the high voltage positive terminal 111 of the high voltage side 11 and the first terminal 131 of the power switch component 13, and the short circuit condition (e.g., current condition) between the high voltage side 11 and the power switch component 13 can be detected by the first current detection component 161. The second current detection component 162 is disposed on the low voltage side 12 to detect the short circuit condition of the low voltage side 12, and therefore can also be referred to as a low voltage side current detection component. Specifically, the second current detection component 162 is electrically connected between the low voltage positive terminal 121 of the low voltage side 12 and the second terminal 132 of the power switch component 13, and the short circuit condition between the low voltage side 12 and the power switch component 13 can be detected by the second current detection component 162. The third current detection component 163 is arranged between the power switch component 13 and the common node d, specifically, the third current detection component 163 is electrically connected between the third end 133 of the power switch component 13 and the common node d, and the short circuit between the high voltage side 11 and the power switch component 13 and the short circuit between the low voltage side 12 and the power switch component 13 can be detected simultaneously by the third current detection component 163. It can be understood that in some embodiments, the first current detection component 161 can also be electrically connected between the high voltage negative terminal 112 of the high voltage side 11 and the common node d, and the second current detection component 162 can also be electrically connected between the low voltage negative terminal 122 of the low voltage side 12 and the common node d, and the present invention does not limit it. In some embodiments, the flying capacitor converter 1a of the energy storage system 4a may not include the first current detection component 161 and the second current detection component 162.

[0084] In the second embodiment, the settings of the first current detection component 161, the second current detection component 162 and the third current detection component 163 can be adjusted according to actual needs. For example, when a short circuit failure does not occur or has a very low probability of occurring on the high-voltage side 11 of the flying capacitor converter 1a, only the second current detection component 162 or the third current detection component 163 can be set; or only the first current detection component 161 and the second current detection component 162 can be set, and the third current detection component 163 is not set, and the present invention does not limit this. In this embodiment, by electrically connecting the third current switch component 153 between the third end 133 of the power switch component 13 and the common node d, the following circuit short circuit conditions can be protected at the same time, including the circuit short circuit condition between the first end 131 and the third end 133 of the power switch component 13, the circuit short circuit condition between the second end 132 and the third end 133 of the power switch component 13, the circuit short circuit condition between the low voltage positive end 121 and the low voltage negative end 122 of the low voltage side 12, the circuit short circuit condition between the low voltage positive end 121 of the low voltage side 12 and the high voltage negative end 112 of the high voltage side 11, and the circuit short circuit condition between the high voltage positive end 111 of the high voltage side 11 and the low voltage negative end 122 of the low voltage side 12. When any of the above circuit short circuit conditions occurs, the above multiple short circuit loops can be completely disconnected by turning off the third current switch component 153.

[0085] In a specific implementation of the second embodiment, when the third current detection component 163 and the third current switch component 153 of the flying capacitor converter 1a of the energy storage system 4a are electrically connected between the third end 133 of the power switch component 13 and the common node d at the same time, the positions of the third current switch component 153 and the third current detection component 163 can be interchanged, that is, the third current switch component 153 is electrically connected between the third end 133 of the power switch component 13 and the third current detection component 163, and the third current detection component 163 is electrically connected between the third current switch component 153 and the common node d. Alternatively, the third current detection component 163 is electrically connected between the third end 133 of the power switch component 13 and the third current switch component 153, and the third current switch component 153 is electrically connected between the third current detection component 163 and the common node d.

[0086] See also Figure 3 , which is a circuit topology diagram of the energy storage system of the third embodiment of this case. Figure 3 As shown, compared to Figure 1The flying capacitor converter 1 of the energy storage system 4 shown in the figure, the flying capacitor converter 1b of the present embodiment further includes a third current switch component 153, which is electrically connected between the current detection component 16 and the common node d, that is, the current detection component 16 and the third current switch component 153 are connected in series between the third end 133 of the power switch component 13 and the common node d. Of course, in some embodiments, the positions of the third current switch component 153 and the current detection component 16 can be interchanged, that is, the third current switch component 153 is electrically connected between the third end 133 of the power switch component 13 and the current detection component 16, and the current detection component 16 is electrically connected between the third current switch component 153 and the common node d. Furthermore, the flying capacitor converter 1b of the energy storage system 4b of the third embodiment further comprises a first current switch component 151 and / or a second current switch component 152, wherein the first current switch component 151 is electrically connected to the high voltage side 11 of the flying capacitor converter 1b, and the second current switch component 152 is electrically connected to the low voltage side 12 of the flying capacitor converter 1b. Specifically, the first current switch component 151 is electrically connected between the high voltage positive terminal 111 of the high voltage side 11 of the flying capacitor converter 1b and the first terminal 131 of the power switch component 13, or the first current switch component 151 is electrically connected between the high voltage negative terminal 112 of the high voltage side 11 of the flying capacitor converter 1b and the common node d; the second current switch component 152 is electrically connected between the low voltage positive terminal 121 of the low voltage side 12 of the flying capacitor converter 1b and the second terminal 132 of the power switch component 13, or the second current switch component 152 is electrically connected between the low voltage negative terminal 122 of the low voltage side 12 of the flying capacitor converter 1b and the common node d. In the third embodiment, by electrically connecting the first current switch component 151 to the high voltage side 11 of the flying capacitor converter 1b and / or electrically connecting the second current switch component 152 to the low voltage side 12 of the flying capacitor converter 1b, in addition to protecting against the several current short circuit conditions mentioned in the second embodiment, it is also possible to protect against the current short circuit condition between the high voltage positive terminal 111 of the high voltage side 11 and the low voltage positive terminal 121 of the low voltage side 12 and to protect against the current short circuit condition between the high voltage negative terminal 112 of the high voltage side 11 and the low voltage negative terminal 122 of the low voltage side 12.

[0087] In a specific implementation of the third embodiment, the third current switch component 153 includes, for example, a fifth current switch S9 and a sixth current switch S10, wherein the fifth current switch S9 and the sixth current switch S10 are connected in reverse series to respectively transmit the current flowing into the power switch component 13 and the current flowing out of the power switch component 13. In some other embodiments, the third current switch component 153 may include only a single current switch to save the configuration cost of the current switch.

[0088] Similar to the first embodiment, the flying capacitor converter 1 of the second embodiment and the third embodiment may also include four mechanical switches, namely, a first mechanical switch K1, a second mechanical switch K2, a third mechanical switch K3 and a fourth mechanical switch K4, wherein the first mechanical switch K1, the second mechanical switch K2, the third mechanical switch K3 and the fourth mechanical switch K4 of the second and third embodiments are similar to the first mechanical switch K1, the second mechanical switch K2, the third mechanical switch K3 and the fourth mechanical switch K4 of the first embodiment, and thus will not be described in detail herein.

[0089] See also Figure 4 , which is a circuit topology diagram of the energy storage system of the fourth embodiment of this case. Figure 4 As shown, compared to Figure 3 The flying capacitor converter 1b of the energy storage system 4b shown in the figure, the energy storage system 4c of this embodiment includes a voltage converter 1c, and the number of power switches and capacitors in the power switch component 13 of the voltage converter 1c is greater, for example, further including a fifth power switch S11, a sixth power switch S12, a seventh power switch S13, an eighth power switch S14 and a fourth capacitor C4. The fifth power switch S11, the sixth power switch S12, the seventh power switch S13 and the eighth power switch S14 are connected in series between the second end 132 and the third end 133 in sequence, wherein the connection between the fifth power switch S11 and the sixth power switch S12 constitutes a fourth connection point E, the connection between the sixth power switch S12 and the seventh power switch S13 constitutes a fifth connection point F, and the connection between the seventh power switch S13 and the eighth power switch S14 constitutes a seventh connection point G. The fourth capacitor C4 is electrically connected between the fourth connection point E and the seventh connection point G, and in this embodiment, the inductor L1 is electrically connected between the second connection point B and the fifth connection point F. The power switch component 13 of this embodiment forms a buck-boost topology. The current detection component and current switch component provided in the energy storage system 4c of this embodiment are shown in FIG. Figure 1-3 Of course, the power switch component 13 of the voltage converter 1c of the energy storage system 4c of this embodiment can also be applied to Figure 1 and Figure 2 The energy storage system will not be described in detail here.

[0090] Of course, the number and location of the current detection components and current switch components of the flying capacitor converter of the energy storage system of the present invention can be changed according to user needs, and are not limited to the configuration of the above embodiment, which will not be repeated here.

[0091] In some embodiments, the voltage converter of the energy storage system may include only three ports, namely, a high voltage positive terminal, a low voltage positive terminal, and a common negative terminal. Figure 5 , which is a circuit topology diagram of the energy storage system of the fifth embodiment of this case. Figure 5 As shown, compared to Figure 3 The energy storage system 4b shown in the figure, the energy storage system 4d of this embodiment includes a high-voltage positive terminal 111, a low-voltage positive terminal 121 and a common negative terminal 14, and the common negative terminal 14 is electrically connected to the common node d, and serves as the negative terminal of the high-voltage side 11 and the low-voltage side 12. Compared with the energy storage system including four terminals, the energy storage system 4d of this embodiment can save cables. The current detection component and the current switch component set in the energy storage system 4d of this embodiment, please refer to Figure 1-3 The description is not repeated here.

[0092] In summary, the flying capacitor converter and voltage converter of the energy storage system of the present case include a current detection component and a controller, and the current detection component is electrically connected between the third end of the power switch component and the common node. When the current detection component detects that the current condition of the common node of the flying capacitor converter and the voltage converter is short-circuited, the controller controls the operation of the current switch component to disconnect the connection between the power switch component and the high-voltage side and / or the low-voltage side. Therefore, the flying capacitor converter and voltage converter of the present case trigger the protection action when a short-circuit fault occurs, and will not form a large short-circuit current, so that the safety of the overall energy storage system is higher. In addition, the current flowing through the common node in the flying capacitor converter and voltage converter of the energy storage system of the present case is small, so that the current detection component that detects the current flowing through the common node can use a smaller specification component, thereby reducing the volume of the current detection component and reducing its cost. The current switch component connected in series at the common node can use a smaller specification component, thereby reducing the volume of the current switch component and reducing its cost, reducing losses, improving the efficiency of the overall energy storage system, and easier to heat dissipate. Furthermore, when applied to a flying capacitor converter, when the current condition on the high voltage side and / or the low voltage side of the flying capacitor converter is short-circuited, one or more discharge currents generated by the first power source, the second power source, the first capacitor, the second capacitor and / or the third capacitor will all flow through a common node and can be quickly detected by a current detection component to improve the short circuit detection speed of the flying capacitor converter.

Claims

1. A flying capacitor converter, electrically connected between a first power source and a second power source, wherein the flying capacitor converter comprises: A high-voltage side, electrically connected to the first power source, and comprising a high-voltage positive terminal and a high-voltage negative terminal; A low voltage side, electrically connected to the second power source, and comprising a low voltage positive terminal and a low voltage negative terminal; A common node is located between the low voltage negative terminal of the low voltage side and the high voltage negative terminal of the high voltage side; a power switch component electrically connected between the high voltage side and the low voltage side, and comprising a first end, a second end and a third end, and comprising a first power switch, a second power switch, a third power switch and a fourth power switch sequentially connected in series between the first end and the third end of the power switch component; At least one current switch component, electrically connected to the high voltage side, the low voltage side and / or the common node; a current detection component, electrically connected between the third terminal of the power switch component and the common node, for detecting a current condition of the flying capacitor converter; and A controller is electrically connected to the current detection component and the at least one current switch component. When the current detection component detects that the current condition is a short circuit, the controller controls the operation of the at least one current switch component to disconnect the connection between the power switch component and the high voltage side and / or the connection between the power switch component and the low voltage side.

2. A flying capacitor converter as described in claim 1, wherein the at least one current switch component includes a first current switch component and / or a second current switch component, the first current switch component is electrically connected between the high-voltage positive end of the high-voltage side and the first end of the power switch component or between the high-voltage negative end of the high-voltage side and the common node, and / or the second current switch component is electrically connected between the low-voltage negative end of the low-voltage side and the common node or between the low-voltage positive end of the low-voltage side and the second end of the power switch component.

3. A flying capacitor converter as described in claim 1 or 2, wherein the at least one current switch component includes a third current switch component, and the third current switch component and the current detection component are connected in series between the third end of the power switch component and the common node. 4 . The flying capacitor converter as claimed in claim 1 , wherein each of the current switch components comprises two current switches connected in reverse series or one current switch.

5. The flying capacitor converter as claimed in claim 1, wherein the flying capacitor converter comprises at least one mechanical switch electrically connected to the high voltage positive terminal, the high voltage negative terminal of the high voltage side, the low voltage positive terminal and / or the low voltage negative terminal of the low voltage side.

6. The flying capacitor converter as described in claim 1, wherein the power switch component further includes a first capacitor, a second capacitor, a third capacitor and an inductor, the connection between the first power switch and the second power switch constitutes a first connection point, the connection between the second power switch and the third power switch constitutes a second connection point, the connection between the third power switch and the fourth power switch constitutes a third connection point, the first capacitor is electrically connected between the first end and the third end of the power switch component, the second capacitor is electrically connected between the first connection point and the third connection point, the third capacitor is electrically connected between the second end and the third end of the power switch component, and the inductor is electrically connected between the second connection point and the second end of the power switch component.

7. A flying capacitor converter, electrically connected between a first power source and a second power source, wherein the flying capacitor converter comprises: A high-voltage side, electrically connected to the first power source, and comprising a high-voltage positive terminal and a high-voltage negative terminal; A low voltage side, electrically connected to the second power source, and comprising a low voltage positive terminal and a low voltage negative terminal; A common node is located between the low voltage negative terminal of the low voltage side and the high voltage negative terminal of the high voltage side; a power switch component, electrically connected between the high voltage side and the low voltage side, comprising a first end, a second end and a third end, and comprising a first power switch, a second power switch, a third power switch and a fourth power switch, which are sequentially connected in series between the first end and the third end of the power switch component; A single current switch component electrically connected between the third terminal of the power switch component and the common node; at least one current detection component, electrically connected to the high voltage side, the low voltage side and / or the common node, for detecting a current condition of the flying capacitor converter; and A controller is electrically connected to the current detection component and the current switch component. When the current detection component detects that the current condition is a short circuit, the controller controls the operation of the current switch component to disconnect the connection between the power switch component and the high voltage side and / or the connection between the power switch component and the low voltage side. 8 . The flying capacitor converter as claimed in claim 7 , wherein the at least one current detection component and the current switch component are connected in series between the third terminal of the power switch component and the common node.

9. A flying capacitor converter as described in claim 7, wherein the at least one current detection component includes a first current detection component and / or a second current detection component, the first current detection component is electrically connected between the high-voltage positive end of the high-voltage side and the first end of the power switch component or between the high-voltage negative end of the high-voltage side and the common node, and / or the second current detection component is electrically connected between the low-voltage negative end of the low-voltage side and the common node or between the low-voltage positive end of the low-voltage side and the second end of the power switch component. 10 . The flying capacitor converter as claimed in claim 7 , wherein the current switch component comprises two switch elements connected in reverse series or one switch element.

11. The flying capacitor converter as claimed in claim 7, wherein the flying capacitor converter comprises at least one mechanical switch electrically connected to the high voltage positive terminal, the high voltage negative terminal of the high voltage side, the low voltage positive terminal and / or the low voltage negative terminal of the low voltage side.

12. The flying capacitor converter as described in claim 7, wherein the power switch component further includes a first capacitor, a second capacitor, a third capacitor and an inductor, the connection between the first power switch and the second power switch constitutes a first connection point, the connection between the second power switch and the third power switch constitutes a second connection point, the connection between the third power switch and the fourth power switch constitutes a third connection point, the first capacitor is electrically connected between the first end and the third end of the power switch component, the second capacitor is electrically connected between the first connection point and the second connection point, the third capacitor is electrically connected between the second end and the third end of the power switch component, and the inductor is electrically connected between the second connection point and the second end of the power switch component.

13. A voltage converter, comprising: A high voltage side and a low voltage side, electrically connected to a common node; a power switch component electrically connected between the high voltage side, the low voltage side and the common node; At least one current switch component is disposed in at least one power loop of the voltage converter; and A current detection component is arranged between the power switch component and the common node, and is used for detecting a current condition of the common node.

14. The voltage converter of claim 13, wherein the voltage converter further comprises: A controller is electrically connected to the current detection component and the at least one current switch component, and is configured to control the operation of the at least one current switch component based on the detected current condition.

15. The voltage converter as claimed in claim 14, wherein when the current detection component detects that the current condition is a short circuit, the controller controls the at least one current switch component to disconnect the connection between the power switch component and the high voltage side and / or the connection between the power switch component and the low voltage side.

16. A voltage converter as described in claim 13, wherein the at least one current switching component includes: a first current switching component, arranged in the power circuit between the high voltage side and the power switching component; and / or a second current switching component, arranged in the power circuit between the low voltage side and the power switching component.

17. The voltage converter as claimed in claim 13 or 16, wherein the at least one current switch component comprises a third current switch component, which is arranged in the power loop between the power switch component and the common node and is connected in series with the current detection component.

18. The voltage converter of claim 14, wherein the at least one current switch component comprises a single current switch component disposed in the power loop between the power switch component and the common node and connected in series with the current detection component.

19. The voltage converter of claim 18, wherein the voltage converter further comprises: a high-voltage side current detection component, electrically connected to the high-voltage side and configured to detect a current condition of the high-voltage side; and / or a low-voltage side current detection component, electrically connected to the low-voltage side and configured to detect a current condition of the low-voltage side; and The controller is also electrically connected to the high-voltage side current detection component and / or the low-voltage side current detection component; in, When the current condition of the high voltage side and / or the current condition of the low voltage side is detected as a short circuit, the controller controls the current switch component to disconnect the connection between the power switch component and the high voltage side and the connection between the power switch component and the low voltage side.

20. The voltage converter of claim 13, wherein the current flowing through the common node is a difference between the current flowing through the low voltage side and the current flowing through the high voltage side.

21. The voltage converter of claim 13, wherein a current flowing through the common node is smaller than a current flowing through the low voltage side.

22. A voltage converter, comprising: A high voltage side and a low voltage side, electrically connected to a common node; a power switch component electrically connected between the high voltage side, the low voltage side and the common node; a current switch component, disposed between the power switch component and the common node; a high-voltage side current detection component, electrically connected to the high-voltage side and configured to detect a current condition of the high-voltage side; a low-voltage side current detection component, electrically connected to the low-voltage side and configured to detect a current condition of the low-voltage side; and a controller electrically connected to the current switch component, the high-voltage side current detection component and the low-voltage side current detection component; in, When the current condition of the high voltage side and / or the current condition of the low voltage side is detected as a short circuit, the controller controls the current switch component to disconnect the connection between the power switch component and the high voltage side and the connection between the power switch component and the low voltage side.

23. An energy storage system comprising: At least one flying capacitor converter as claimed in claims 1 and 7; a power source electrically connected to the high voltage side of the flying capacitor converter; and An energy storage element is electrically connected to the low voltage side of the flying capacitor converter.

24. An energy storage system comprising: At least one voltage converter as claimed in claim 13 or 22; a power source electrically connected to the high voltage side of the voltage converter; and An energy storage element is electrically connected to the low voltage side of the voltage converter.

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