Power system

Abstract

The utility model provides a power system. The electric power system comprises a power device, an energy storage device, an energy conversion assembly, a first buffer unit and a second buffer unit. The energy storage device is provided with at least one energy storage element capable of outputting direct current, the power device comprises a charge storage element, the first buffer unit is connected between the energy storage element and the charge storage element of the power device, and the first buffer unit is used for buffering current flowing from the energy storage element to the charge storage element of the power device. The energy conversion assembly comprises at least one electrical device provided with a charge storage element, the second buffer unit is connected between the energy storage element and the charge storage element of the electrical device, and the second buffer unit is used for buffering current flowing from the energy storage element to the charge storage element of the electrical device after the first buffer unit completes current buffering. According to the application, the current buffering of the power device and the energy transmission and distribution assembly can be ensured to be smoothly carried out, so that the smooth starting of the power system is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the electrical technical field, in particular to a power system. BACKGROUND

[0002] The direct current power system can be applied to the fields of automobiles, ships and the like. When the direct current power system is started, part of the devices in the direct current power system is prone to be impacted by current mutation, thereby causing damage to the part of the devices. In the related art, a buffer circuit can be added in the direct current power system, so as to reduce voltage fluctuation when the direct current power system is started, to protect the part of the devices from being affected by overload and transient current, and to ensure stable operation of the system. However, the buffer circuit design scheme can cause the problem of failure of starting of the direct current power system. CONTENT OF THE UTILITY MODEL

[0003] Therefore, one of the purposes of the present application is to provide a power system.

[0004] In a first aspect, the embodiments of the present application provide a power system. The power system comprises a power device, an energy storage device, an energy conversion assembly, a first buffer unit and a second buffer unit. The energy storage device has at least one energy storage element capable of outputting direct current, the power device comprises a charge storage element, the first buffer unit is connected between the energy storage element and the charge storage element of the power device, and the first buffer unit is used for buffering current flowing from the energy storage element to the charge storage element of the power device. The energy conversion assembly comprises at least one electrical device provided with the charge storage element, the second buffer unit is connected between the energy storage element and the charge storage element of the electrical device, and the second buffer unit is used for buffering current flowing from the energy storage element to the charge storage element of the electrical device after the first buffer unit completes current buffering.

[0005] In some embodiments, the first buffer unit and the second buffer unit are both arranged inside the energy storage device.

[0006] In some embodiments, the first buffer unit is arranged inside the energy storage device, and the second buffer unit is arranged independently of the energy storage device and is detachably connected with the energy storage device.

[0007] In some embodiments, the power system further comprises a busbar box, the busbar box comprises a busbar circuit, the busbar circuit is connected between the energy storage device and the driver, and is connected between the energy storage device and the second buffer unit.

[0008] In some embodiments, the first buffer unit is arranged inside the energy storage device, and the second buffer unit is arranged inside the busbar box.

[0009] In some embodiments, the first buffer unit is arranged inside the energy storage device, and the second buffer unit is arranged independently from the busbar box and is detachably connected to the busbar box.

[0010] In some embodiments, the electrical device comprises at least one of a rectifier device, an inverter device, a DC / DC converter device, and an MPPT device.

[0011] In some embodiments, the electrical device comprises the rectifier device, and the power system further comprises a DC bus connected between the second buffer unit and a charge storage element of the rectifier device, and the rectifier device is further configured to connect to an AC power source; and a communication line is connected between the rectifier device and the energy storage device. When the power system is in a sailing mode, the rectifier device outputs a constant current to the DC bus; and when the power system is in a charging mode, the rectifier device receives a current signal sent by the energy storage device through the communication line, and outputs a variable current to the DC bus based on the current signal.

[0012] In some embodiments, the power system further comprises an AC bus, an input end of the AC bus is configured to connect to the AC power source, and an output end of the AC bus is configured to connect to an AC load. A switch connected between the AC bus and the AC power source is mutually exclusive with a switch connected between the rectifier device and the AC power source.

[0013] In some embodiments, the electrical device further comprises the inverter device, and the DC bus is connected between the second buffer unit and a charge storage element of the inverter device. The power system further comprises an AC bus, one input end of the AC bus is configured to connect to the AC power source, another input end of the AC bus is configured to connect to the inverter device, and an output end of the AC bus is configured to connect to an AC load. A switch connected between the AC bus and the AC power source is mutually exclusive with a switch connected between the AC bus and the inverter device.

[0014] The power system of the embodiment of the present application comprises a first buffer unit and a second buffer unit. The first buffer unit is used for current buffering of the charge storage element in the power device, and the second buffer unit is used for current buffering of the charge storage element of the energy conversion assembly after the first buffer unit completes the current buffering. In this way, the current buffering of the power device and the current buffering of the energy supply and distribution assembly are respectively implemented by two buffer units, and the two current buffering processes are performed in two stages, thereby avoiding the problem that the current buffering cannot meet the current buffering requirements of multiple devices due to the current buffering performed only by the buffer unit inside the battery, and ensuring that the current buffering of the power device and the energy supply and distribution assembly can be successfully performed, and further ensuring the smooth start of the power system.

[0015] Additional aspects and advantages of the embodiments of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or related technical description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0017] Figure 1 The power connection schematic diagram of the power system of one embodiment of the present application.

[0018] Figure 2 The power connection schematic diagram of the power system of another embodiment of the present application.

[0019] Figure 3 The power and communication connection schematic diagram of the power system of one embodiment of the present application.

[0020] Figure 4 The topology schematic diagram of the power system of one embodiment of the present application. DETAILED DESCRIPTION

[0021] The exemplary embodiments will be described in detail hereinafter with reference to the accompanying drawings. The following description relates to the drawings, in which the same numbers denote the same or similar elements throughout the several drawings.

[0022] In the related art, a power system in a direct current networking mode can include multiple devices with charge storage elements. For example, in a power system including a battery and a power device, the battery supplies power to the power device. Since the driver of the power device has a charge storage element, such as a capacitor, inside. Before the high-voltage loop of the battery is closed, the capacitor in the driver does not store charge or only stores a small amount of charge, and the input impedance of the circuit is very low. Then, at the moment when the high-voltage loop of the battery is closed, the capacitor will be charged to a high voltage in a short time, at which time a sharp current will occur, which can cause the capacitor to be broken down, causing damage to the driver. Therefore, it is necessary to buffer the current flowing into the capacitor before the high-voltage loop of the battery is closed to avoid the occurrence of sharp current, so as to ensure the safe operation of the device. To this end, a buffer circuit can be connected between the battery and the driver to achieve current buffering. However, due to user needs, additional rectifier devices, inverter devices and other devices with charge storage elements can be configured in the power system. When these devices are powered on during system startup, the current flowing to these devices also needs to be buffered to reduce the risk of device damage. However, the current buffer circuit can not meet the current buffering needs of so many devices, resulting in the power system failing to start successfully.

[0023] Based on this, please refer to Figure 1 The embodiment of the present application provides a power system 100. The power system 100 can be a direct current networking system and can be applied to the fields of automobiles, ships and the like. The embodiment of the present application takes the power system 100 as a ship power system 100 for example for description, but cannot be understood as a limitation to the present application. The power system 100 includes a power device 12, an energy storage device 11, an energy conversion assembly 21, a first buffer unit 30 and a second buffer unit 40.

[0024] The energy storage device 11 can be a chargeable battery, a fuel cell or other device with energy storage function. The energy storage device 11 has at least one energy storage element 111 capable of outputting direct current. For example, when the energy storage device 11 is a chargeable battery, the energy storage element 111 can be a battery cell. The energy storage device 11 can further include a battery management system (BMS). The BMS is connected with the battery cell and is used to monitor the operating parameters of the energy storage element 111 and can manage the energy storage element 111 based on the operating parameters. For example, the BMS can monitor the remaining capacity of the energy storage element 111 and close the output of the energy storage element 111 when the remaining capacity is low.

[0025] The power device 12 can be a marine propeller or the like capable of outputting power. The power device 12 has a motor 121 for outputting power and a driver 122 connected to the motor 121. The driver 122 is used to drive the operation of the motor 121. The propeller is provided with a propeller connected to the motor 121, and the motor 121 drives the propeller to rotate to output propelling power. The driver 122 controls the rotation speed and direction of the motor 121. The energy storage element 111 outputs a direct current to the driver 122, and the driver 122 converts the direct current to an alternating current to the motor 121 to drive the motor 121 to output torque.

[0026] The first buffer unit 30 is connected between the energy storage element 111 and the driver 122. The first buffer unit 30 is used to buffer the current flowing from the energy storage element 111 to the driver 122. Specifically, the driver 122 is provided with a charge storage element such as a capacitor. The first buffer unit 30 has a first connection line and a second connection line connected in parallel. The first connection line is connected with a first switch and a first current limiting element (such as a resistor), and the second connection line is connected with a second switch. When the first buffer unit 30 is running, the first switch is first closed to make the first connection line conductive, so as to charge the capacitor to reduce the current flowing through the capacitor, that is, to achieve current buffering. When the voltage of the capacitor reaches a certain value, the second switch is closed to make the second connection line conductive, and the first switch is opened, so as to realize the power supply of the energy storage unit to the driver 122. Among them, for the current flowing from the energy storage element 111 to the driver 122, the current flowing process is that the current is first output from the energy storage element 111, then flows through the first buffer unit 30, and then flows into the driver 122.

[0027] The energy conversion assembly 21 includes at least one electrical device 210 provided with a charge storage element 2101. The second buffer unit 40 is connected between the energy storage element 111 and the charge storage element 2101. The second buffer unit 40 is used to buffer the current flowing from the energy storage element 111 to the charge storage element 2101 after the first buffer unit 30 completes the current buffering. For example, please refer to the description of the first buffer unit 30. Figure 4The electrical device 210 can include at least one of a rectifier 211 (AC-DC), an inverter 212 (DC-AC), a direct current conversion device 213 (DC-DC), and a maximum power point tracking controller (MPPT 214). The rectifier 211, the inverter 212, the direct current conversion device 213, and the MPPT 214, etc. have energy conversion functions and are usually provided with a charge storage element 2101 such as a capacitor. When starting, these devices also need to be current buffered to avoid damage caused by inrush current. The second buffer unit 40 has a third connection line and a fourth connection line connected in parallel. The third connection line is connected with a third switch and a second current limiting element, and the fourth connection line is connected with a fourth switch. When the second buffer unit 40 is running, the third switch is first closed to turn on the third connection line, thereby charging the capacitor in the electrical device 210 to achieve current buffering. When the voltage of the capacitor reaches a certain value, the fourth switch is closed to turn on the fourth connection line, and the third switch is opened, thereby achieving power transmission from the energy storage unit to the energy conversion assembly 21. The current flowing from the energy storage element 111 to the charge storage element 2101 in the energy conversion assembly 21 flows through the first buffer unit 30 and the second buffer unit 40 in sequence after being output from the energy storage element 111. That is, the first buffer unit 30 and the second buffer unit 40 are connected in series.

[0028] The current buffering of the embodiment of the present application is divided into two stages. In the first stage, the first buffer unit 30 is enabled to perform current buffering on the driver 122. After the first buffer unit 30 completes the current buffering, the first stage ends and enters the second stage, and at this time the second buffer unit 40 is enabled to perform current buffering on the charge storage element 2101 in the energy conversion assembly 21. In this way, in the first stage, the energy conversion assembly 21 remains in a powered-off state to ensure that the energy storage device 11 can successfully perform current buffering and the energy storage device 11 can successfully enter a high-voltage power supply state, thereby ensuring the smooth start of the power system 100. After the system is started smoothly, it enters the second stage, and at this time the second buffer unit 40 performs current buffering to ensure the safe activation of other devices in the power system 100.

[0029] The power system 100 of the embodiments of the present application is provided with a first buffer unit 30 and a second buffer unit 40. The first buffer unit 30 is configured to perform current buffering for the driver 122 of the power device 12, and the second buffer unit 40 is configured to perform current buffering for the charge storage element 2101 of the energy conversion assembly 21 after the first buffer unit 30 completes the current buffering. In this way, the current buffering of the power device 12 and the current buffering of the energy conversion assembly are respectively implemented by two buffer units, and the two current buffering processes are performed in two stages, thereby avoiding the problem that the current buffering performed by the buffer unit inside the battery alone cannot meet the current buffering requirement of multiple devices, and ensuring that the current buffering of the power device 12 and the current buffering of the energy conversion assembly can be successfully performed, and further ensuring the smooth start of the power system 100.

[0030] In some embodiments, referring to Figure 2 , the power system 100 can further include a busbar box 13. The busbar box 13 includes a busbar circuit 131. The busbar circuit 131 is connected between the energy storage device 11 and the driver 122, and is connected between the energy storage device 11 and the second buffer unit 40. The busbar box 13 can realize the orderly connection and busbar of multiple energy storage elements 111, and can timely cut off the connection line between the energy storage element 111 and the rear-end device (such as the power device 12, the energy conversion assembly 21, etc.) when an abnormality (such as an abnormality of the energy storage element 111, an abnormality of the connection line, etc.) occurs, so as to protect the rear-end device.

[0031] In some embodiments, the first buffer unit 30 and the second buffer unit 40 can have multiple setting modes.

[0032] In a first example, the first buffer unit 30 and the second buffer unit 40 can be both arranged inside the energy storage device 11. This setting mode is beneficial to improve the integration of the devices in the system, and the maintenance of the devices is more convenient.

[0033] In a second example, referring to Figure 1The first buffer unit 30 can be arranged inside the energy storage device 11, and the second buffer unit 40 can be arranged independently of the energy storage device 11 and detachably connected to the energy storage device 11. In this arrangement, the second buffer unit 40 and the energy storage device 11 are two independent devices, and the second buffer unit 40 can be connected to the energy storage device 11 through a wire with a plug interface to realize power transmission. In this way, the devices in the power system 100 are designed in a decentralized and modular manner, which makes it convenient for users to install the devices in the power system 100 when the power system 100 is installed on a ship with a small space, and the power system 100 can be applied to a wider range of ships and has stronger scene adaptability. In addition, in the related art, the energy storage device 11 and the power device 12 can be combined into a basic marine power system 100. However, some users may want to upgrade the marine power system 100, for example, by additionally configuring an energy conversion device to realize power supply for daily loads on the ship or to improve the endurance of the marine power system 100. In this case, arranging the second buffer unit 40 independently of the energy storage device 11 can avoid the need for secondary development of the energy storage device 11 in the basic system, which is conducive to reducing development costs.

[0034] In a third example, the first buffer unit 30 can be arranged inside the energy storage device 11, and the second buffer unit 40 can be arranged inside the busbar box 13. This arrangement is conducive to improving the integration of devices in the system and facilitating device maintenance.

[0035] In a fourth example, please refer to Figure 2 The first buffer unit 30 is arranged inside the energy storage device 11, and the second buffer unit 40 is arranged independently of the busbar box 13 and detachably connected to the busbar box 13. In this arrangement, the second buffer unit 40 and the busbar box 13 are two independent devices, and the second buffer unit 40 can be connected to the busbar box 13 through a wire with a plug interface to realize current transmission. This decentralized and modular design can facilitate the installation of the power system 100 on a ship with a small space.

[0036] Figure 4 A topology diagram of an embodiment of the power system 100 of the present application. As shown in Figure 4As shown, the power system 100 comprises an energy storage device 11, a busbar box 13, a power device 12, a control device 14, a display device 15, a first buffer unit 30 (not shown), a second buffer unit 40, a first DC bus 221, a second DC bus 222, an AC bus 223, a rectifier device 211, an inverter device 212, an MPPT 214, a DC conversion device 213 and a battery 231. The power device 12 is internally provided with an electronic control unit (not shown), which is in communication connection with the control device 14 and the display device 15. The control device 14 can transmit instructions to the electronic control unit to realize the control of the power device 12, and the display device 15 can receive the information fed back by the electronic control unit to display the relevant parameters of the power system 100, such as the operating mode of the power system 100, the operating state of each device in the power system 100, the fault information of the power system 100, etc. The display device 15 can also receive user operations and generate instructions to realize the operation control of the power system 100. The energy storage device 11, the busbar box 13, the power device 12, the control device 14, the display device 15, the second buffer unit 40, the first DC bus 221, the second DC bus 222, the AC bus 223, the rectifier device 211, the inverter device 212, the MPPT 214, the DC conversion device 213 and the battery 231 in the power system 100 are all modularly designed, so that any two devices in the plurality of devices are independent of each other, and the devices associated with each other can be connected through wires with connectors. With such a decentralized modular design, on the one hand, different users can flexibly configure the power system 100 according to their own needs, and on the other hand, it is also convenient to install the power system 100 into a ship with small space.

[0037] Figure 4In the shown power system 100, the first buffer unit 30 is arranged inside the energy storage device 11. The busbar box 13 is connected between the first buffer unit 30 and the power device 12, and is connected between the first buffer unit 30 and the second buffer unit 40. One end of the second buffer unit 40 is connected to the first DC bus 221. The input end of the rectifier device 211 is used to connect an AC power source, such as an AC generator, AC shore power, etc., and the output end of the rectifier device 211 is connected to the first DC bus 221. The rectifier device 211 can convert AC power output by the AC device into DC power to be transmitted to the first DC bus 221. The power output by the rectifier device 211 can be provided to the power device 12 and other daily-use loads, and can also be provided to the energy storage device 11 to charge the energy storage device 11. The input end of the MPPT 214 is connected to the photovoltaic panel, and the output end of the MPPT 214 is connected to the first DC bus 221. The MPPT 214 can achieve maximum power point tracking during operation of the photovoltaic panel. The power output by the MPPT 214 can be provided to the power device 12 and other daily-use loads, and can also be provided to the energy storage device 11. The input end of the inverter device 212 is connected to the first DC bus 221, and the output end of the inverter device 212 is used to connect a high-voltage daily-use load. The inverter device 212 can be used to convert DC power output by the first DC bus 221 into AC power to be provided to the high-voltage daily-use load. It should be noted that, Figure 4 The voltage of the high-voltage daily-use load shown in the figure is 220V, and in other embodiments, the voltage of the high-voltage daily-use load can also be 380V, etc., which is not limited in the present application. The number of DC conversion devices 213 can be one or more. Figure 4 In the shown example, the number of DC conversion devices 213 is two. One of the DC conversion devices 213 has an input end connected to the first DC bus 221 and an output end connected to the second DC bus 222. The DC conversion device 213 is used to step down DC power output by the first DC bus 221. The power output by the DC conversion device 213 is used to provide power to the control device 14, the display device 15, the electronic control unit inside the power device 12, etc. The second DC bus 222 is also connected to the storage battery 231. In this way, when the power system 100 is in sleep mode and there is no power transmission on the first DC bus 221, the storage battery 231 can supply power to the electronic control unit, the control device 14, the display device 15, etc. through the second DC bus 222. The other DC conversion device 213 has an input end connected to the first DC bus 221 and an output end used to connect a low-voltage daily-use load. The DC conversion device 213 is used to step down DC power output by the first DC bus 221 to supply power to the low-voltage daily-use load.

[0038] Please refer to Figure 3 and Figure 4In some embodiments, the power system 100 further comprises an energy management device 50 connected with the second DC bus 222 for power supply. The energy management device 50 is in communication connection with the energy storage device 11, the power device 12, the control device 14, the display device 15, the energy conversion assembly 21 and the like. The energy management device can implement energy management, fault management and the like of the system to ensure the safety and stability of the operation of the power system 100.

[0039] The power system 100 has multiple working modes. In an example, the working modes of the power system 100 include a shutdown mode, a sailing mode and a charging mode. In the shutdown mode, the energy management device 50 and the electronic control unit receive the power provided by the storage battery 231 through the second DC bus 222, and the energy storage device 11, the energy conversion assembly 21 and the like are in a powered-off state, so as to maximize the reduction of energy loss. In the sailing mode, the energy storage device 11 and the energy conversion assembly 21 are in a powered-on state. At this time, if the power system 100 is connected with an AC generator, the energy management device 50 can make an access decision of the AC generator according to the remaining power of the energy storage device 11. For example, when the remaining power is lower than a first power threshold, the AC generator is controlled to start to supply power to the power device 12, the high / low voltage daily load and charge the energy storage device 11. When the power of the energy storage device 11 reaches a second power threshold, the AC generator is controlled to stop. In the charging mode, the energy management device 50 can control the rectifier device 211 to work to charge the energy storage device 11.

[0040] In some embodiments, the energy management device 50 can obtain the associated parameters of the energy conversion assembly and determine the operation time of the second buffer unit 40 based on the associated parameters, so as to control the second buffer unit 40 to operate according to the operation time to complete the current buffering. The associated parameters of the energy conversion assembly may, for example, be the capacity of the capacitor in each electrical device 210 connected with the power system 100. The energy management device 50 determines the operation time based on the sum of the capacities of the capacitors in all electrical devices 210, and controls the closing time of the third switch of the second buffer unit 40 to be equal to the operation time, so as to ensure that the energy conversion assembly 21 can be successfully activated. The embodiments of the present application set the operation time of the second buffer unit 40 according to the specific configuration of the energy conversion assembly, which can ensure the successful completion of the current buffering. Moreover, the user has greater flexibility when configuring the power system 100, which is conducive to improving the user experience.

[0041] In some embodiments, as Figure 3As shown, the rectifier 211 is connected with the energy storage device 11 through a separate communication line, i.e. only the rectifier 211 and the energy storage device 11 transmit data on the communication line. Such design enables the rectifier 211 to work in variable current mode or constant current mode. Specifically, when the power system 100 is in sailing mode, the rectifier 211 works in constant current mode, and converts the alternating current output by the alternating current energy source into direct current, and provides the direct current to the power device 12, daily load and energy storage battery through the first direct current bus 221. When the power system 100 is in charging mode, the rectifier 211 works in variable current mode, and at this time the rectifier 211 can receive the current signal transmitted by the energy storage device 11 through the communication line, and output variable current to the first direct current bus 221 according to the indication of the current signal, thereby ensuring the reliability and safety of battery charging. It should be noted that when the rectifier 211 works in constant current mode, the current value in this mode can be a default value, or can be set by the user according to the requirement. For example, the user can set the output current of the rectifier 211 on the display device 15, the display device 15 generates corresponding instructions and transmits the instructions to the energy management device 50, and the energy management device 50 forwards the instructions to the rectifier 211, so that the rectifier 211 outputs constant current based on the value set by the user.

[0042] In some embodiments, the energy management device 50 communicates with the power device 12, specifically the energy management device 50 communicates with the electronic control unit in the power device 12. The energy management device 50 can transmit power device 12 enable or lock instructions to the electronic control unit, and the electronic control unit controls the operation of the driver 122 and the motor 121 in the power device 12 based on the above instructions. The electronic control unit will monitor the communication state between it and the energy management device 50 in real time, and when the communication is abnormal, the electronic control unit will control the driver 122 to reduce the output power, thereby ensuring the safety of the ship operation.

[0043] Figure 4In the illustrated example, the power system 100 further includes a plurality of switches integrated to the busbars. Specifically, the plurality of switches includes switches integrated to the first DC busbar 221, switches integrated to the second DC busbar 222, and switches integrated to the AC busbar 223. Among them, the number of switches integrated to the first DC busbar 221 is five, including a switch connected between the rectifier device 211 and the first DC busbar 221, a switch connected between the inverter device 212 and the first DC busbar 221, a switch connected between the MPPT 214 and the first DC busbar 221, a switch connected between one of the DC conversion devices 213 and the first DC busbar 221, and a switch connected between the other DC conversion device 213 and the first DC busbar 221. The number of switches integrated to the second DC busbar 222 is two, including a switch connected between one of the DC conversion devices 213 and the battery 231, and a switch connected between the one of the DC conversion devices 213 and the DC load. The number of switches integrated to the AC busbar 223 is four, including a switch connected between the rectifier device 211 and the AC energy source, a switch connected between the AC busbar 223 and the AC energy source, a switch connected between the inverter device 212 and the AC busbar 223, and a switch connected between the AC busbar 223 and the high-voltage daily load. Each of the above-mentioned switches is used to turn on or turn off the connection line where it is located.

[0044] The AC busbar 223 and the rectifier device 211 can be directly connected to the AC energy source, so the current transmitted from the AC energy source to the high-voltage daily load has two transmission paths. One of the transmission paths is that the current flows from the AC energy source, through the AC busbar 223, and then to the high-voltage daily load, and the other transmission path is that the current flows from the AC energy source, through the rectifier device 211, the first DC busbar 221, the inverter device 212, the AC busbar 223, and then to the high-voltage daily load. In the embodiment of the present application, the two transmission paths are mutually exclusive, that is, the switch connected between the AC busbar 223 and the AC energy source and the switch connected between the rectifier device 211 and the AC energy source are mutually exclusive. In this way, in some scenarios, such as when the energy storage battery is fully charged and the user has a demand for using the high-voltage daily load, the current output by the AC energy source can directly flow to the high-voltage daily load through the AC busbar 223, without passing through the rectifier device 211, the first DC busbar 221, and the inverter device 212, which is beneficial to reduce the loss in the process of power transmission.

[0045] In addition, the AC busbar 223 can be directly connected to the AC power source, and the AC busbar 223 is connected to the first DC busbar 221 through the inverter device 212. Therefore, the power input mode of the AC busbar 223 includes receiving power directly from the AC power source or receiving power provided by the inverter device 212 or the energy storage device 11 from the inverted AC power source. Since the power input from the two input modes is AC, if the two inputs are enabled at the same time, the current loop problem caused by the mismatch of the AC phase may occur, which threatens the safety of the power system 100. Therefore, in the embodiment of the present application, the switch connected between the AC busbar 223 and the AC power source and the switch connected between the AC busbar 223 and the inverter device 212 are mutually exclusive. In this way, only one AC power can be input to the AC busbar 223 at the same time, thereby avoiding the current loop and improving the safety of the power system 100.

[0046] The above-mentioned switch exclusive design can be realized by a hardware circuit or a mechanical structure, and the present application does not limit this.

[0047] It should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. The terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0048] The various technical features in the above embodiments can be combined in any way, as long as the combination of the features does not conflict or contradict. Therefore, any combination of the various technical features in the above embodiments also falls within the scope disclosed by the present specification.

[0049] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and are only used to help understand the method of the present application and its core idea, and cannot be understood as a limitation of the present application. Those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A power system, characterized in that, The power system includes a power unit, an energy storage unit, an energy conversion component, a first buffer unit, and a second buffer unit; The energy storage device has at least one energy storage element capable of outputting direct current, the power device includes a charge storage element, and the first buffer unit is connected between the energy storage element and the charge storage element of the power device. The first buffer unit is used to buffer the current flowing from the energy storage element to the charge storage element of the power device. The energy conversion component includes at least one electrical device equipped with the charge storage element. The second buffer unit is connected between the energy storage element and the charge storage element of the electrical device. The second buffer unit is used to buffer the current flowing from the energy storage element to the charge storage element of the electrical device after the first buffer unit has completed current buffering.

2. The power system according to claim 1, characterized in that, Both the first buffer unit and the second buffer unit are located inside the energy storage device.

3. The power system according to claim 1, characterized in that, The first buffer unit is disposed inside the energy storage device, and the second buffer unit is disposed independently of the energy storage device and is detachably connected to the energy storage device.

4. The power system according to claim 1, characterized in that, The power system also includes a combiner box, which includes a combiner circuit connected between the energy storage device and the power device, and also connected between the energy storage device and the second buffer unit.

5. The power system according to claim 4, characterized in that, The first buffer unit is located inside the energy storage device, and the second buffer unit is located inside the combiner box.

6. The power system according to claim 4, characterized in that, The first buffer unit is located inside the energy storage device, and the second buffer unit is located independently of the combiner box and is detachably connected to the combiner box.

7. The power system according to claim 1, characterized in that, The electrical equipment includes at least one of a rectifier, an inverter, a DC-DC converter, and an MPPT.

8. The power system according to claim 7, characterized in that, The electrical equipment includes the rectifier, and the power system further includes a DC busbar connected between the second buffer unit and the charge storage element of the rectifier. The rectifier is also used to connect to an AC energy source. A communication line is connected between the rectifier and the energy storage device. When the power system is operating in navigation mode, the rectifier outputs a constant current to the DC busbar; When the power system is operating in charging mode, the rectifier receives the current signal sent by the energy storage device through the communication line, and outputs a changing current to the DC bus based on the current signal.

9. The power system according to claim 8, characterized in that, The power system also includes an AC busbar, the input end of which is used to connect to the AC energy source, and the output end of which is used to connect to the AC load. The switch connected between the AC busbar and the AC energy source and the switch connected between the rectifier and the AC energy source are mutually exclusive.

10. The power system according to claim 8, characterized in that, The electrical equipment also includes the inverter, the DC busbar is connected between the second buffer unit and the charge storage element of the inverter, the power system also includes an AC busbar, one input terminal of the AC busbar is used to connect to the AC energy source, the other input terminal of the AC busbar is used to connect to the inverter, the output terminal of the AC busbar is used to connect to the AC load, and the switch connected between the AC busbar and the AC energy source and the switch connected between the AC busbar and the inverter are mutually exclusive.

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