Electric vehicle charging and energy storage system

Abstract

An electric vehicle charging and energy storage system, comprising a photovoltaic panel (101), an energy storage battery (102), a hybrid inverter (103) and an isolated power converter (104); the hybrid inverter (103) is connected to the photovoltaic panel (101) and the energy storage battery (102), and is connected to an external power grid at the same time for implementing energy exchange between the photovoltaic panel (101), the energy storage battery (102) and the power grid; the isolated power converter (104) and the hybrid inverter (103) are of an integrated structure or a separated structure, and the hybrid inverter (103) is directly or indirectly connected to an electric vehicle by means of the isolated power converter (104) and is used for performing charging and discharging operations on the electric vehicle.

Description

Electric vehicle charging and energy storage systems

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202311254141.1 filed with the State Intellectual Property Office of China on September 26, 2023, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of energy storage technology, and more specifically, to an electric vehicle charging and energy storage system. Background Art

[0004] At present, the development of home energy storage systems and electric vehicle DC charging systems has become relatively mature. Among them, the home energy storage system is similar to a micro energy storage power station, which can charge itself during periods of low electricity consumption and be used as an emergency power supply during peak electricity consumption periods. It can also be used to balance electricity loads; the electric vehicle DC charging system uses an external charging module to provide high-voltage DC energy to the battery.

[0005] However, home energy storage systems and electric vehicle charging DC systems are generally two independent systems. With the popularization of electric vehicles in households, different solutions need to be used to meet household electricity needs or vehicle charging needs, which is not conducive to saving resources and rational use of electricity.

[0006] Summary of the Invention

[0007] Based on the above background, the present application proposes an electric vehicle charging and energy storage system, comprising: a photovoltaic panel, an energy storage battery and a hybrid inverter; the hybrid inverter connects the photovoltaic panel, the energy storage battery and the power grid, and is used to realize energy exchange among the power grid, the photovoltaic panel and the energy storage battery; an isolated power converter, wherein the isolated power converter and the hybrid inverter are an integrated structure or a separate structure, and the hybrid inverter is indirectly or directly connected to the electric vehicle through the isolated power converter, and is used to charge and discharge the electric vehicle.

[0008] Optionally, the hybrid inverter includes a non-isolated power optimizer, a non-isolated bidirectional inverter, a bus, a first switching device, a second switching device, a third switching device and a fourth switching device. The photovoltaic panel is connected to the bus through the non-isolated power optimizer, and the power grid is connected to the bus through the non-isolated bidirectional inverter; the bus is connected to the first end of the isolated power converter through the first switching device, the energy storage battery is connected to the second end of the isolated power converter through the second switching device, the electric vehicle is connected to the first end of the isolated power converter through the third switching device, and the electric vehicle is connected to the second end of the isolated power converter through the fourth switching device.

[0009] Optionally, the third switching device is connected in parallel to an end of the first switching device close to the isolated power converter, and the fourth switching device is connected in parallel to an end of the second switching device close to the isolated power converter.

[0010] Optionally, when the first switching device is closed, the fourth switching device is closed, the second switching device and the third switching device are opened, the busbar supplies power to the electric vehicle through a first circuit consisting of the first switching device, the isolated power converter and the fourth switching device, and the electric vehicle reversely discharges the busbar through the first circuit.

[0011] Optionally, when the second switching device is closed, the third switching device is closed, the first switching device and the fourth switching device are disconnected, and the energy storage battery supplies power to the electric vehicle through a second circuit consisting of the second switching device, the isolated power converter and the third switching device, and the electric vehicle reversely discharges the energy storage battery through the second circuit.

[0012] Optionally, the hybrid inverter includes a non-isolated power optimizer, a non-isolated bidirectional inverter, a bus and a non-isolated power converter, the photovoltaic panel is connected to the bus through the non-isolated power optimizer, the power grid is connected to the bus through the non-isolated bidirectional inverter, and the energy storage battery is connected to the bus through the non-isolated power converter.

[0013] Optionally, the hybrid inverter is connected to the isolated power converter through the energy storage battery and then connected to the electric vehicle.

[0014] Optionally, the hybrid inverter is connected to the isolated power converter through the bus bar and then connected to the electric vehicle.

[0015] Optionally, the hybrid inverter includes an energy management module, which is used to schedule energy flow between the photovoltaic panel, the energy storage battery and the power grid.

[0016] Optionally, the hybrid inverter is connected to a household load and is also used to supply power to the household load.

[0017] Therefore, the present application provides an electric vehicle charging and energy storage system, comprising: a photovoltaic panel, an energy storage battery, a hybrid inverter, and an isolated power converter; the hybrid inverter is connected to the photovoltaic panel, the energy storage battery, and the power grid, and is used to realize energy exchange among the power grid, the photovoltaic panel, and the energy storage battery; the hybrid inverter is connected to the electric vehicle through the isolated power converter, and is used to charge and discharge the electric vehicle. Therefore, the system provided by the present application realizes power supply to household loads and reasonable scheduling of electric energy between the photovoltaic panel, the energy storage battery, and the power grid during off-peak and peak periods through the connection of the photovoltaic panel, the energy storage battery, and the power grid with the hybrid inverter. Furthermore, the same system is used to realize electric vehicle charging and discharging operations through the isolated power converter, thereby solving all the electricity usage needs of an average household with one system, and realizing reasonable scheduling and optimization of electric energy.

[0018] Other features and advantages of the embodiments of the present application will be described in the following description and, in part, will become apparent from the description or be understood by practicing the embodiments of the present application. The objectives and other advantages of the embodiments of the present application can be achieved and obtained through the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] FIG1 shows a schematic structural diagram of an electric vehicle charging and energy storage system shown in an embodiment of the present application.

[0021] FIG2 shows a schematic structural diagram of another electric vehicle charging and energy storage system shown in an embodiment of the present application.

[0022] FIG3 shows a schematic structural diagram of another electric vehicle charging and energy storage system shown in an embodiment of the present application.

[0023] FIG4 shows a schematic structural diagram of another electric vehicle charging and energy storage system shown in an embodiment of the present application.

[0024] FIG5 shows a schematic structural diagram of yet another electric vehicle charging and energy storage system shown in an embodiment of the present application.

[0025] FIG6 shows a schematic structural diagram of yet another electric vehicle charging and energy storage system according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work fall within the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0028] Please refer to Figure 1, which shows an electric vehicle charging and energy storage system 100 provided in an embodiment of the present application. Specifically, the electric vehicle charging and energy storage system 100 includes a photovoltaic panel 101, an energy storage battery 102, a hybrid inverter 103, and an isolated power converter 104, wherein the hybrid inverter 103 is connected to the photovoltaic panel 101 and the energy storage battery 102 while being connected to an external power grid, and is used to realize energy exchange between the photovoltaic panel 101, the energy storage battery 102, and the power grid. The isolated power converter 104 and the hybrid inverter 103 are of an integrated structure or a separate structure, and the hybrid inverter 103 is indirectly or directly connected to the electric vehicle through the isolated power converter 104, and is used to charge and discharge the electric vehicle.

[0029] Specifically, photovoltaic panels 101, hybrid inverter 103, and energy storage battery 102 can form a basic home energy storage system. Both photovoltaic panels 101 and energy storage battery 102 are connected to hybrid inverter 103, which is also connected to the power grid. In one embodiment, hybrid inverter 103 is also connected to home load 105. Photovoltaic panels are used to convert solar energy into electrical energy. Hybrid inverters not only convert the electrical energy from the photovoltaic panels into AC power, but also regulate and optimize the electrical energy. Therefore, during periods of low electricity demand, when the photovoltaic panels and the power grid have excess power, photovoltaic panels 101 can simultaneously supply power to household loads 105 through hybrid inverter 103 and charge energy storage battery 102. Similarly, the power grid can simultaneously supply power to household loads 105 through hybrid inverter 103 and charge energy storage battery 102. During peak electricity demand, when the photovoltaic panels and the power grid have insufficient power, energy storage battery 102 can reversely discharge power through hybrid inverter 103 to supply both household loads 105 and the power grid, thereby achieving the rational scheduling and utilization of electrical energy. Household loads refer to devices in a household that require power supply, such as common household appliances like televisions and air conditioners, lighting equipment like electric lamps, and communication devices like computers and mobile phones.

[0030] Furthermore, the hybrid inverter 103 is directly or indirectly connected to the electric vehicle via the isolated power converter 104. Thus, the hybrid inverter 103 can also transmit electrical energy from the photovoltaic panel 101, the energy storage battery 102, or the power grid to the electric vehicle via the isolated power converter 104, thereby charging the electric vehicle. Furthermore, when the isolated power converter 104 is a bidirectional converter, the electric vehicle can also discharge the electrical energy back to the photovoltaic panel 101, the energy storage battery 102, or the power grid via the isolated power converter 104. The electric vehicle can be a pure electric vehicle, i.e., a vehicle powered entirely by electricity, or a hybrid vehicle, i.e., a vehicle powered by both fuel and electricity. Therefore, the electric vehicle charging and energy storage system 100 can not only supply power to household loads and rationally dispatch electrical energy between the photovoltaic panel, the energy storage battery, and the power grid during off-peak and peak periods, but can also use the same system to charge and discharge the electric vehicle via the isolated power converter. This single system addresses all the electrical energy needs of a typical household, achieving rational dispatch and optimization of electrical energy.

[0031] As an implementation, the isolated power converter may be an isolated bidirectional DC-DC converter. For example, the circuit topology used in the isolated bidirectional DC-DC converter may be an LLC series-parallel resonant converter circuit, a phase-shifted full-bridge converter circuit, or a dual-active full-bridge converter circuit. This isolation solution isolates the vehicle's charging and discharging power branch circuit from the entire energy storage system, creating an electrically isolated, independent, ungrounded safety system, thereby ensuring absolute safety during the electric vehicle charging and discharging process.

[0032] As an embodiment, the hybrid inverter 103 includes an energy management module, which is used to schedule the energy flow between the photovoltaic panels, the energy storage battery and the power grid. For example, it can be as complex as an energy management system (EMS) or as simple as a microcontroller unit (MCU).

[0033] Therefore, the present application provides an electric vehicle charging and energy storage system, comprising a photovoltaic panel, an energy storage battery, a hybrid inverter, and an isolated power converter; the hybrid inverter connects the photovoltaic panel, the energy storage battery, and the power grid to realize energy exchange among the power grid, the photovoltaic panel, and the energy storage battery; the isolated power converter and the hybrid inverter are an integrated structure or a separate structure, and the hybrid inverter is indirectly or directly connected to the electric vehicle through the isolated power converter to perform charging and discharging operations on the electric vehicle. Therefore, the system provided by the present application realizes power supply to household loads and reasonable scheduling of electric energy between the photovoltaic panel, the energy storage battery, and the power grid during off-peak and peak periods by connecting the photovoltaic panel, the energy storage battery, and the power grid to the hybrid inverter. Furthermore, the same system is used to realize electric vehicle charging and discharging operations through the isolated power converter, thereby solving all the electricity usage needs of an average household with one system and realizing reasonable scheduling and optimization of electric energy.

[0034] Please refer to Figure 2, which shows a schematic structural diagram of another electric vehicle charging and energy storage system 200 shown in an embodiment of the present application. Specifically, the electric vehicle charging and energy storage system 200 includes a photovoltaic panel 201, an energy storage battery 202, a hybrid inverter 203 and an isolated power converter 204, wherein the hybrid inverter 203 is connected to the photovoltaic panel 201 and the energy storage battery 202 while being connected to the external power grid, for realizing energy exchange between the photovoltaic panel 201, the energy storage battery 202 and the power grid, the hybrid inverter 203 and the isolated power converter 204 are an integrated structure, and the hybrid inverter 203 is directly connected to the electric vehicle through the isolated power converter 204 to perform charging and discharging operations on the electric vehicle. As an embodiment, the hybrid inverter 203 is also connected to a household load 205.

[0035] Furthermore, the hybrid inverter 203 includes a non-isolated power optimizer 211, a non-isolated bidirectional inverter 212, a bus 213, a first switch device 214, a second switch device 215, a third switch device 216 and a fourth switch device 217, wherein the photovoltaic panel 201 is connected to the bus 213 through the non-isolated power optimizer 211, the power grid is connected to the bus 213 through the non-isolated bidirectional inverter 212, the bus 213 is connected to the first end of the isolated power converter 204 through the first switch device 214, the energy storage battery 202 is connected to the second end of the isolated power converter 204 through the second switch device 215, the electric vehicle is connected to the first end of the isolated power converter 204 through the third switch device 216, and the electric vehicle is connected to the second end of the isolated power converter 204 through the fourth switch device 217.

[0036] It can be understood that since the isolated power converter 204 and the hybrid inverter 203 are an integrated structure, the hybrid inverter can be directly connected to the electric vehicle based on the isolated power converter 204, and the hybrid inverter can also be directly connected to the energy storage battery based on the isolated power converter 204. When the switching devices on the circuit consisting of the bus, the energy storage battery and the electric vehicle are reasonably combined to control the on and off of the bus and the energy storage battery circuit, the bus and the electric vehicle circuit, and the energy storage battery and the electric vehicle circuit, only one isolated power converter can be used to realize the energy flow between the bus, the energy storage battery and the electric vehicle. Compared with the prior art where the hybrid inverter needs to add an additional non-isolated power converter to connect to the energy storage battery, the structure of the hybrid inverter is optimized and the cost is reduced.

[0037] Specifically, the photovoltaic panel 201 supplies power to the household load 205 through the hybrid inverter 203 in the following manner: the electric energy generated by the photovoltaic panel 201 is transmitted to the bus 213 via the non-isolated power optimizer 211; the bus 213 is used to collect, distribute and transmit electric energy, and then the electric energy is supplied to the household load 205 via the non-isolated bidirectional inverter 212; during the off-peak period, when the electric energy on the photovoltaic panel 201 is surplus after supplying electricity to the household load, the hybrid inverter 203 can also be used to charge the energy storage battery 202. Specifically, the electric energy generated by the photovoltaic panel 201 is transmitted to the bus 213 via the non-isolated power optimizer 211; the bus 213 is used to collect, distribute and transmit electric energy, and then the electric energy is supplied to the household load 205 via the non-isolated bidirectional inverter 212; during the off-peak period, when the electric energy on the photovoltaic panel 201 is surplus after supplying electricity to the household load, the hybrid inverter 203 can be used to charge the energy storage battery 202. The power is transmitted to the bus 213 through the non-isolated power optimizer 211, and then supplied to the energy storage battery 202 through the first switch device 214, the isolated power converter 204 and the second switch device 215. It can be understood that at this time, the first switch device 214 and the second switch device 215 are closed, and the third switch device 216 and the fourth switch device 217 are disconnected, that is, the photovoltaic panel-energy storage battery circuit is connected, and the photovoltaic panel-electric vehicle circuit is disconnected. In other words, the photovoltaic panel can only supply power to any one of the electrical appliances in the energy storage battery or the electric vehicle at the same time.

[0038] Specifically, when the grid has a surplus after providing electricity to household loads during off-peak periods, it can also charge the energy storage battery 202 through the hybrid inverter 203. The specific method can be: the grid power is transmitted to the bus 213 via the non-isolated bidirectional inverter 212, and then supplied to the energy storage battery 202 via the first switch device 214, the isolated power converter 204 and the second switch device 215. It can be understood that at this time, the first switch device 214 and the second switch device 215 are closed, and the third switch device 216 and the fourth switch device 217 are disconnected, that is, the grid-to-energy storage battery loop is connected, while the grid-to-electric vehicle loop is disconnected. In other words, the grid can only supply power to either the energy storage battery or the electric vehicle at any one time.

[0039] Specifically, the energy storage battery 202 supplies power to the household load 205 via the hybrid inverter 203 in the following manner: the electrical energy stored in the energy storage battery 202 from the photovoltaic panel 201 and the power grid is transmitted to the bus 213 via the second switch device 215, the isolated power converter 204, and the first switch device 214. The bus 213 is used to collect, distribute, and transmit electrical energy, and then supplies the electrical energy to the household load 205 via the non-isolated bidirectional inverter 212. It will be understood that at this time, the first switch device 214 and the second switch device 215 are closed, and the third switch device 216 and the fourth switch device 217 are open. That is, the circuit between the energy storage battery and the household load is connected, while the circuit between the energy storage battery and the electric vehicle is disconnected. In other words, the energy storage battery can only supply power to one of the household loads or the electric vehicle at a time.

[0040] Specifically, the photovoltaic panel 201 supplies power to the electric vehicle through the hybrid inverter 203 in the following manner: the electric energy generated by the photovoltaic panel 201 is transmitted to the bus 213 via the non-isolated power optimizer 211, and then supplied to the electric vehicle via the first switch device 214, the isolated power converter 204 and the fourth switch device 217. It can be understood that at this time, the first switch device 214 and the fourth switch device 217 are closed, and the second switch device 215 and the third switch device 216 are disconnected, that is, the photovoltaic panel-electric vehicle loop is connected, and the photovoltaic panel-energy storage battery loop is disconnected; the grid supplies power to the electric vehicle through the hybrid inverter 203 in the following manner: the grid power is transmitted to the bus 213 via the non-isolated power optimizer 211, and then supplied to the electric vehicle via the first switch device 214, the isolated power converter 204 and the fourth switch device 217. The bidirectional inverter 212 transmits power to the bus 213, which is then supplied to the electric vehicle via the first switch 214, the isolated power converter 204, and the fourth switch 217. At this time, the first switch 214 and the fourth switch 217 are closed, while the second switch 215 and the third switch 216 are open. This means that the grid-electric vehicle circuit is open, while the grid-energy storage battery circuit is open. The energy storage battery can supply power to the electric vehicle via the hybrid inverter 203 by directly supplying the electrical energy stored in the energy storage battery 202 from the photovoltaic panel 201 and the grid to the electric vehicle via the second switch 215, the isolated power converter 204, and the third switch 216. It is understood that at this time, the second switch 215 and the third switch 216 are closed, while the first switch 214 and the fourth switch 217 are open. This means that the grid-electric vehicle circuit is open, while the grid-energy storage battery circuit is open.

[0041] Based on the above analysis, it can be seen that if the energy storage battery and the household load are regarded as the same type of load, the electric vehicle charging and energy storage system 200 has the characteristic that the power supply end can only supply power to the same type of load and any electrical device in the electric vehicle at the same time. Therefore, as an embodiment, the third switching device 216 is connected in parallel to the end of the first switching device 214 close to the isolated power converter 204, and the fourth switching device 217 is connected in parallel to the end of the second switching device 215 close to the isolated power converter 204. For example, when the first switch device 214 is disconnected, the connection between the busbar 213 and the isolated power converter 204 is disconnected. At this time, the energy storage battery 202 will not be able to supply power to the household load, but the energy storage battery 202 can still supply power to the electric vehicle by closing the third switch device 216. When the second switch device 215 is disconnected, the connection between the energy storage battery 202 and the isolated power converter 204 is disconnected. At this time, the busbar 213 will not be able to supply power to the energy storage battery 202, but at the same time, the photovoltaic panel 201 and the power grid can still charge the electric vehicle by closing the fourth switch device 217. Therefore, by reasonably setting the connection relationship of the switching devices, it can be ensured that the power supply end can only supply power to one type of load and any electrical device in the electric vehicle at the same time.

[0042] Specifically, the electric vehicle charging and energy storage system 200 can also enable the electric vehicle to reversely discharge power to the grid circuit or energy storage battery during peak power consumption periods. For example, the electric vehicle can reversely discharge power to the grid circuit by transmitting the electric energy of the electric vehicle to the bus 213 via the fourth switch device 217, the isolated power converter 204, and the first switch device 214. After the bus collects and distributes the electric energy, it can be transmitted to the grid via the non-isolated bidirectional inverter 212 or to household loads via the non-isolated bidirectional inverter 212. The electric vehicle can reversely discharge power to the energy storage battery by transmitting the electric energy of the electric vehicle to the energy storage battery 202 via the third switch device 216, the isolated power converter 204, and the second switch device 215.

[0043] As an embodiment, when the photovoltaic panel 201 and the power grid supply power to the energy storage battery 202 or the electric vehicle through the isolated power converter 204, one end of the isolated power converter 204 connected by the first switch device 214 and the third switch device 216 is the input end, and one end of the isolated power converter 204 connected by the second switch device 215 and the fourth switch device 217 is the output end; when the energy storage battery 202 supplies power to the electric vehicle or the household load through the isolated power converter 204, one end of the isolated power converter 204 connected by the first switch device 214 and the third switch device 216 is the output end, and one end of the isolated power converter 204 connected by the second switch device 215 and the fourth switch device 217 is the input end, and the same applies to other situations.

[0044] As an implementation method, the non-isolated power optimizer 211 can be a non-isolated maximum power point tracking (MPPT) power optimizer. The MPPT power optimizer is used to adjust the load connected to the system to match the load curve with the highest power transmission efficiency, so that the system has the best power generation efficiency. The power branch circuit of the non-isolated solution is not completely isolated from the entire energy storage system, but its safety protection measures can be provided by the housing of the hybrid inverter, etc., thereby achieving the purpose of reducing costs.

[0045] As an implementation manner, the first switching device 214 , the second switching device 215 , the third switching device 216 and the fourth switching device 217 may be intelligent switching devices, for example, relays, contactors and other switching devices.

[0046] As an embodiment, the hybrid inverter 203 further includes an energy management module, which can be, for example, a complex EMS system or a simple microcontroller, a single-chip microcomputer, etc. The energy management module is connected to the non-isolated power optimizer 211, the non-isolated bidirectional inverter 212, the isolated power converter 204, the first switch device 214, the second switch device 215, the third switch device 216, and the fourth switch device 217, and is used to control the opening and closing of the first switch device 214, the second switch device 215, the third switch device 216, and the fourth switch device 217. At the same time, the energy flow between the photovoltaic panel, the power grid, the energy storage battery, the electric vehicle, and the household load is dispatched through the non-isolated power optimizer 211, the non-isolated bidirectional inverter 212, and the isolated power converter 204.

[0047] As an embodiment, the isolated power converter can be an isolated bidirectional DC-DC converter. For example, the circuit topology used in the isolated bidirectional DC-DC converter can be an LLC series-parallel resonant conversion circuit, a phase-shifted full-bridge conversion circuit, or a dual-active full-bridge conversion circuit.

[0048] Therefore, the present application provides an electric vehicle charging and energy storage system, including photovoltaic panels, energy storage batteries, hybrid inverters and isolated power converters. The hybrid inverter includes a non-isolated power optimizer, a non-isolated bidirectional inverter, a bus, a first switch device, a second switch device, a third switch device and a fourth switch device. The bus is connected to the first end of the isolated power converter through the first switch device, the energy storage battery is connected to the second end of the isolated power converter through the second switch device, the electric vehicle is connected to the first end of the isolated power converter through the third switch device, and the electric vehicle is connected to the second end of the isolated power converter through the fourth switch device. Thus, the system sets four switch devices and intelligently controls their opening and closing to enable the photovoltaic power converter to The solar panel, the power grid, and the energy storage battery can all charge the electric vehicle, and the energy storage battery and the electric vehicle can reversely discharge the power to the power grid loop. Furthermore, by connecting the third switching device in parallel to the end of the first switching device close to the isolated power converter, and connecting the fourth switching device in parallel to the end of the second switching device close to the isolated power converter, it is ensured that the power supply end can only supply power to one type of load and any one electrical device in the electric vehicle at the same time. Therefore, the system provided by the embodiment of the present application makes full use of the isolated power converter, and saves the non-isolated power converter that must be included in the hybrid inverter of the ordinary household energy storage system in the system architecture, which not only reduces the size of the hybrid inverter, but also reduces the cost and improves the conversion efficiency.

[0049] Please refer to Figure 3, which shows a schematic structural diagram of another electric vehicle charging and energy storage system 300 shown in an embodiment of the present application. Specifically, the electric vehicle charging and energy storage system 300 includes a photovoltaic panel 301, an energy storage battery 302, a hybrid inverter 303 and an isolated power converter 304, wherein the hybrid inverter 303 is connected to the photovoltaic panel 301 and the energy storage battery 302 while being connected to the external power grid, and is used to realize energy exchange between the photovoltaic panel 301, the energy storage battery 302 and the power grid. The hybrid inverter 303 and the isolated power converter 304 are an integrated structure. The hybrid inverter 303 is indirectly connected to the isolated power converter 304 through the energy storage battery 302, and thus connected to the electric vehicle through the isolated power converter 304 to perform charging and discharging operations on the electric vehicle. As an embodiment, the hybrid inverter 303 is also connected to a household load 305. Furthermore, the hybrid inverter 303 includes a non-isolated power optimizer 311, a non-isolated bidirectional inverter 312, a bus 313 and a non-isolated power converter 314. The photovoltaic panel 301 is connected to the bus 313 through the non-isolated power optimizer 311, the power grid is connected to the bus 313 through the non-isolated bidirectional inverter 312, and the energy storage battery 302 is connected to the bus 313 through the non-isolated power converter 314.

[0050] The hybrid inverter 303 is connected to the isolated power converter 304 and the electric vehicle via the energy storage battery 302. The energy flow relationship between the basic home energy storage system composed of the photovoltaic panel 301, the hybrid inverter 303, and the energy storage battery 302 can refer to the aforementioned embodiment. The method for charging the electric vehicle can be: the electrical energy generated by the photovoltaic panel 301 is transmitted to the bus 313 via the non-isolated power optimizer 311, and then transmitted to the electric vehicle via the non-isolated power converter 314 and the isolated power converter 304; the electrical energy generated by the grid is transmitted to the bus 313 via the non-isolated bidirectional inverter 312, and then transmitted to the electric vehicle via the non-isolated power converter 314 and the isolated power converter 304; and at the same time, the electrical energy stored in the energy storage battery 302 from the photovoltaic panel 301 and the grid is directly supplied to the electric vehicle via the isolated power converter 204. Similarly, the electric vehicle can discharge its electric energy back to the grid by directly discharging it back to the energy storage battery 302 via the isolated power converter 204 ; or, the electric energy of the electric vehicle can be discharged to the bus 313 via the isolated power converter 204 and the non-isolated power converter 314 , and the bus 313 can be discharged to the grid or household load 305 via the non-isolated bidirectional inverter 312 .

[0051] For example, please refer to Figure 4, which shows a schematic structural diagram of another electric vehicle charging and energy storage system 300, in which the hybrid inverter 303 and the isolated power converter 304 can also be separated structures, with the isolated power converter 304 being provided outside the hybrid inverter 303, and the hybrid inverter 303 being connected to the electric vehicle via the isolated power converter 304. Furthermore, the energy flow method of this example is the same as that of the above embodiment and will not be repeated here.

[0052] As an embodiment, the hybrid inverter 303 can also be connected to the isolated power converter 304 and connected to the electric vehicle via the busbar 313. Specifically, please refer to Figure 5, which shows a schematic structural diagram of another electric vehicle charging and energy storage system 300. The hybrid inverter 303 and the isolated power converter 304 are an integrated structure. In this case, the energy flow relationship between the basic home energy storage system composed of the photovoltaic panel 301, the hybrid inverter 303, and the energy storage battery 302 can refer to the above embodiment. The method for charging the electric vehicle can be: the electric energy generated by the photovoltaic panel 301 is transmitted to the busbar 313 via the non-isolated power optimizer 311, and the electric energy generated by the grid is also transmitted to the busbar 313 via the non-isolated power optimizer 311. After the busbar collects and distributes the electric energy, it is directly transmitted to the electric vehicle through the isolated power converter 304; then the isolated power converter 304 transmits it to the electric vehicle; at the same time, the electric energy stored in the energy storage battery 302 from the photovoltaic panel 301 and the grid is supplied to the electric vehicle via the non-isolated power optimizer 311 and the isolated power converter 204. Similarly, the electric vehicle can discharge the electric energy back to the grid loop in the following ways: the electric energy of the electric vehicle is discharged back to the energy storage battery 302 via the isolated power converter 204 and the non-isolated power converter 314; or the electric energy of the electric vehicle is discharged directly to the bus 313 via the isolated power converter 204, and the bus 313 is then discharged to the grid or household load 305 via the non-isolated bidirectional inverter 312.

[0053] For example, please refer to FIG6 , which shows a schematic structural diagram of another electric vehicle charging and energy storage system 300, in which the hybrid inverter 303 and the isolated power converter 304 can also be separated structures, with the isolated power converter 304 being provided outside the hybrid inverter 303, and the hybrid inverter 303 being connected to the electric vehicle via the isolated power converter 304. Furthermore, the energy flow method of this example is the same as that of the above embodiment and will not be repeated here.

[0054] It is understandable that the hybrid inverter 303 is connected to the isolated power converter 304 and the electric vehicle through different devices. During the charging and discharging process of the electric vehicle, the charging and discharging circuits are different based on the different connection relationships. Specifically, if the hybrid inverter 303 is connected to the electric vehicle via the energy storage battery 302 and the isolated power converter 304, then when energy exchange occurs between the energy storage battery 302 and the electric vehicle, only one isolated power converter 304 is required. When energy exchange occurs between the photovoltaic panel 301 or the power grid and the electric vehicle, an isolated power converter 304 and a non-isolated power optimizer 311 or a non-isolated bidirectional inverter 312 are required. In other words, energy transfer needs to pass through one more device, which will result in one more loss. Therefore, the method of connecting the hybrid inverter 303 to the electric vehicle via the energy storage battery 302 and the isolated power converter 304 is more suitable for scenarios where energy storage batteries are frequently used to charge and discharge electric vehicles, compared with the method in which the hybrid inverter 303 can also be connected to the isolated power converter 304 via the bus 313 to connect to the electric vehicle. Conversely, another embodiment is more suitable for scenarios where electric vehicles are charged and discharged directly through photovoltaic panels or the power grid.

[0055] As an embodiment, the hybrid inverter 303 further includes an energy management module, which can be, for example, a complex EMS system or a simple microcontroller, a single-chip microcomputer, etc. The energy management module is connected to the non-isolated power optimizer 311, the non-isolated bidirectional inverter 312, the non-isolated power converter 314, and the isolated power converter 304, and is used to schedule the energy flow between the photovoltaic panels, the power grid, the energy storage battery, the electric vehicle, and the household load through the non-isolated power optimizer 311, the non-isolated bidirectional inverter 312, the non-isolated power converter 314, and the isolated power converter 304.

[0056] As an implementation manner, the non-isolated power optimizer may be a non-isolated maximum power point tracking (MPPT) power optimizer.

[0057] As an embodiment, the isolated power converter can be an isolated bidirectional DC-DC converter. For example, the circuit topology used in the isolated bidirectional DC-DC converter can be an LLC series-parallel resonant conversion circuit, a phase-shifted full-bridge conversion circuit, or a dual-active full-bridge conversion circuit.

[0058] As an implementation manner, the non-isolated power converter may be a non-isolated bidirectional DC-DC converter.

[0059] Therefore, the present application provides an electric vehicle charging and energy storage system, comprising a photovoltaic panel, an energy storage battery, a hybrid inverter, and an isolated power converter. The hybrid inverter comprises a non-isolated power optimizer, a non-isolated bidirectional inverter, a busbar, and a non-isolated power converter. The photovoltaic panel is connected to the busbar via the non-isolated power optimizer, the grid is connected to the busbar via the non-isolated bidirectional inverter, and the energy storage battery is connected to the busbar via the non-isolated power converter. Furthermore, the hybrid inverter is connected to the isolated power converter via the energy storage battery and then to the electric vehicle, or the hybrid inverter is connected to the isolated power converter via the busbar and then to the electric vehicle. Thus, the connection between the photovoltaic panel, the energy storage battery, and the grid and the hybrid inverter realizes the power supply to the household load and the reasonable scheduling of the electricity between the photovoltaic panel, the energy storage battery, and the grid during off-peak and peak periods. The isolated power converter is connected to the electric vehicle via the hybrid inverter, and the charging and discharging operations of the electric vehicle are realized using a single system, thereby solving all the electricity usage needs of an average household and realizing the reasonable scheduling and optimization of electricity. At the same time, based on different usage scenarios, you can choose whether the hybrid inverter is connected to the isolated power converter through the bus or the energy storage battery to improve the energy utilization of the system in different scenarios.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An electric vehicle charging and energy storage system, characterized in that: include: Photovoltaic panels, energy storage batteries, hybrid inverters and isolated power converters; The hybrid inverter is connected to the photovoltaic panel, the energy storage battery and the power grid, and is used to realize energy exchange among the power grid, the photovoltaic panel and the energy storage battery; The isolated power converter and the hybrid inverter are of an integrated structure or a separate structure, and the hybrid inverter is connected to the electric vehicle indirectly or directly through the isolated power converter to perform charging and discharging operations on the electric vehicle.

2. The system according to claim 1, characterized in that The hybrid inverter comprises a non-isolated power optimizer, a non-isolated bidirectional inverter, a busbar, a first switch device, a second switch device, a third switch device and a fourth switch device, the photovoltaic panel is connected to the busbar through the non-isolated power optimizer, and the power grid is connected to the busbar through the non-isolated bidirectional inverter; The busbar is connected to the first end of the isolated power converter through the first switching device, the energy storage battery is connected to the second end of the isolated power converter through the second switching device, the electric vehicle is connected to the first end of the isolated power converter through the third switching device, and the electric vehicle is connected to the second end of the isolated power converter through the fourth switching device.

3. The system according to claim 2, characterized in that The third switch device is connected in parallel to an end of the first switch device close to the isolated power converter, and the fourth switch device is connected in parallel to an end of the second switch device close to the isolated power converter.

4. The system according to claim 3, characterized in that When the first switch device is closed, the fourth switch device is closed, the second switch device and the third switch device are opened, the busbar supplies power to the electric vehicle through a first circuit consisting of the first switch device, the isolated power converter and the fourth switch device, and the electric vehicle reversely discharges the busbar through the first circuit.

5. The system according to claim 3, characterized in that When the second switch device is closed, the third switch device is closed, the first switch device and the fourth switch device are opened, the energy storage battery supplies power to the electric vehicle through a second circuit consisting of the second switch device, the isolated power converter and the third switch device, and the electric vehicle reversely discharges the energy storage battery through the second circuit.

6. The system according to claim 1, characterized in that The hybrid inverter includes a non-isolated power optimizer, a non-isolated bidirectional inverter, a bus and a non-isolated power converter. The photovoltaic panel is connected to the bus through the non-isolated power optimizer, the power grid is connected to the bus through the non-isolated bidirectional inverter, and the energy storage battery is connected to the bus through the non-isolated power converter.

7. The system according to claim 6, characterized in that The hybrid inverter is connected to the isolated power converter through the energy storage battery and then connected to the electric vehicle.

8. The system according to claim 6, characterized in that The hybrid inverter is connected to the isolated power converter through the bus bar and then connected to the electric vehicle.

9. The system according to any one of claims 1 to 8, characterized in that: The hybrid inverter includes an energy management module, which is used to schedule energy flow between the photovoltaic panel, the energy storage battery and the power grid.

10. The system according to claim 1, characterized in that The hybrid inverter is connected to a household load and is also used to supply power to the household load.

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