Semi-AC bus optical storage overcharge system and overcharge method

Abstract

The invention relates to the technical field of photovoltaics, energy storage, charging piles and the like, and discloses a semi-alternating-current bus optical storage overcharging system and an overcharging method.In the system, one end of each integrated bidirectional AC / DC module is connected to a common alternating-current bus, and the other end of at least one integrated bidirectional AC / DC module is connected with one end of a switch module through an energy storage electricity supplementing module; the other ends of the other integrated bidirectional AC / DC modules are directly connected with one end of the switch module, and the other end of the switch module is connected with a to-be-charged vehicle through a charging terminal; the energy storage system is connected with one end of the switch module through the one-way isolation DC / DC module; and the energy storage system is connected between the integrated bidirectional AC / DC module and the switch module through the energy storage and electricity supplement module. Charging and discharging of the energy storage system are realized by adopting the energy storage charging module, and compared with an existing alternating current scheme, the scheme has the advantages that the use of an AC / DC module is reduced, the system cost is reduced, and the charging efficiency of the energy storage module is improved.

Description

Technical Field

[0001] This invention relates to the fields of photovoltaic, energy storage and charging piles, and specifically to a semi-AC bus photovoltaic-energy storage supercharging system and supercharging method. Background Technology

[0002] Currently, charging systems, energy storage, and photovoltaic systems are all independent systems. To achieve the integration of photovoltaic, energy storage, charging, and discharging, the mainstream solution is to connect the photovoltaic system, energy storage system, and charging system to the power grid to achieve coupling between energy sources on the AC grid side.

[0003] AC-coupled systems are convenient and flexible, with each system operating independently. To enable photovoltaics and energy storage to directly power the charging system, an external energy management system is needed for unified scheduling. However, energy storage systems require multiple AC / DC (alternating current to direct current) conversion stages during charging and discharging, resulting in low charging efficiency and high costs. Summary of the Invention

[0004] In view of this, the present invention provides a semi-AC bus photovoltaic-storage supercharging system and supercharging method to solve the problems of low charging efficiency and high cost of energy storage systems.

[0005] In a first aspect, the present invention provides a semi-AC bus photovoltaic-storage-supercharging system, the system comprising: an energy storage system, an energy storage and replenishment module, a unidirectional isolated DC / DC module, multiple integrated bidirectional AC / DC modules, multiple switch modules, and multiple charging terminals, wherein...

[0006] One end of each of the integrated bidirectional AC / DC modules is connected to a common AC bus, and the other end of at least one of the integrated bidirectional AC / DC modules is connected to one end of the switch module through the energy storage and power replenishment module. The other ends of the remaining integrated bidirectional AC / DC modules are directly connected to one end of the switch module, and the other end of the switch module is connected to the vehicle to be charged through a charging terminal.

[0007] The energy storage system is connected to one end of the switching module through the unidirectional isolated DC / DC module.

[0008] The energy storage system is connected between the integrated bidirectional AC / DC module and the switch module through the energy storage and power replenishment module.

[0009] This invention provides a semi-AC bus photovoltaic-storage supercharging system. By employing an energy storage supplementary power module, the system can achieve charging and discharging of the energy storage system while reducing system costs. Compared with the existing AC scheme that directly charges the energy storage module through the grid, this scheme reduces the use of AC / DC modules, lowers system costs, and improves the charging efficiency of the energy storage module.

[0010] In one optional embodiment, the energy storage and replenishment module includes at least one set of energy storage and replenishment units, each set of energy storage and replenishment units including a replenishment relay group and a charging relay group, wherein,

[0011] One end of the power replenishment relay group is connected to one end of the energy storage system, and the other end of the power replenishment relay group is connected to the other end of the integrated bidirectional AC / DC module and one end of the charging relay group, respectively.

[0012] The other end of the charging relay group is connected to one end of the switch module.

[0013] In existing charging stations, the integration of energy storage and charging stations can be achieved simply by adding a few relays. Compared to DC buses and semi-DC buses, the cost of energy storage integration has been minimized, significantly reducing the investment payback period for charging station customers. Furthermore, retrofitting existing charging stations with energy storage integration is also minimal in terms of difficulty and cost. The flexible switching of relays in the energy storage replenishment module greatly improves the charging and discharging efficiency of the energy storage battery, significantly enhancing the flexibility of energy storage access.

[0014] In one alternative implementation, the control logic of the replenishment relay group and the control logic of the charging relay group are mutually exclusive.

[0015] In the design phase, the control hardware circuits for the two relay groups were designed to be mutually exclusive to avoid fuse burnout accidents.

[0016] In one alternative implementation, the energy storage system includes at least one energy storage unit connected in parallel.

[0017] The capacity of the energy storage system can be expanded by setting up multiple energy storage units and connecting them directly in parallel.

[0018] In one optional implementation, the system further includes: a photovoltaic system and a photovoltaic inverter, wherein,

[0019] The photovoltaic system is connected to the common AC bus via the photovoltaic inverter.

[0020] The main function of this photovoltaic inverter is to convert solar energy into electrical energy and feed it back into the power grid. It can also provide power for vehicle charging through an integrated bidirectional AC / DC module, thereby improving the utilization rate of photovoltaics and preventing the curtailment of solar energy.

[0021] In one optional implementation, the switching module adopts a full matrix energy switching method or a half matrix energy switching method.

[0022] By adopting a full-matrix energy switching method or a half-matrix energy switching method, each charging terminal can have full power output, allowing users to enjoy fast charging services in any parking space.

[0023] In one optional embodiment, the system further includes a liquid cooling system, which exchanges heat with the unidirectional isolated DC / DC module, the photovoltaic inverter, and each of the integrated bidirectional AC / DC modules through a refrigerant in a liquid cooling pipeline.

[0024] By adopting liquid cooling, the power module achieves high stability, long lifespan, low noise, and strong environmental adaptability.

[0025] In a second aspect, the present invention provides a semi-AC bus photovoltaic-storage-supercharging method, based on the semi-AC bus photovoltaic-storage-supercharging system of the first aspect above or any corresponding embodiment thereof, the method comprising:

[0026] When the energy storage system needs to be recharged, the callable integrated bidirectional AC / DC module is locked according to the power to be recharged, the charging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the recharge relay group connected to the callable integrated bidirectional AC / DC module is closed, and the integrated bidirectional AC / DC module is used to recharge the energy storage system.

[0027] When it is not necessary to recharge the energy storage system, disconnect the recharge relay group connected to the callable integrated bidirectional AC / DC module and close the charging relay group connected to the callable integrated bidirectional AC / DC module.

[0028] This invention provides a semi-AC bus photovoltaic-storage supercharging method. By using an energy storage supplementary power module, the system cost is reduced while the energy storage system is charged and discharged. Compared with the existing AC scheme that directly charges the energy storage module through the grid, this scheme reduces the use of AC / DC modules, lowers the system cost, and improves the charging efficiency of the energy storage module.

[0029] In one optional implementation, the step of locking a callable integrated bidirectional AC / DC module based on the power to be replenished when the energy storage system needs to be recharged includes:

[0030] Determine if the current time is during a power grid off-peak period;

[0031] When the current time is during a grid off-peak period, determine whether the remaining power of the energy storage system is not greater than a first preset value;

[0032] When the current time is during a grid off-peak period and the remaining power of the energy storage system is not greater than a first preset value, the power to be replenished is obtained, and the callable integrated bidirectional AC / DC module is locked according to the power to be replenished.

[0033] By utilizing energy storage for peak shaving and valley filling, the energy storage cost of the semi-AC bus photovoltaic-storage-supercharging system has been reduced.

[0034] In one optional implementation, the step of disconnecting the power supply relay group connected to the callable integrated bidirectional AC / DC module and closing the charging relay group connected to the callable integrated bidirectional AC / DC module when it is not necessary to replenish the energy storage system includes:

[0035] Determine whether the energy storage system charging is interrupted or terminated, and whether the energy storage system needs to participate in vehicle charging;

[0036] When the energy storage system's charging is interrupted, charging ends, or the energy storage system needs to participate in vehicle charging, the charging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, and the charging relay group connected to the callable integrated bidirectional AC / DC module is closed.

[0037] In an optional implementation, the method further includes:

[0038] When a power request is received from a vehicle to be charged, it is determined whether the current time is during the peak period of the power grid.

[0039] When the current time is during the peak period of the power grid, determine whether the remaining power of the energy storage system is greater than the second preset value;

[0040] When the current time is during the peak period of the power grid and the remaining power of the energy storage system is greater than the second preset value, the available integrated bidirectional AC / DC module and unidirectional isolated DC / DC module are locked according to the power request.

[0041] The switching module connects the locked module to the vehicle to be charged for charging.

[0042] It provides users with multiple charging paths and selects the most suitable charging method according to specific operating conditions, realizing efficient transmission between the power grid, energy storage, photovoltaics, and charging terminals.

[0043] In an optional implementation, the method further includes:

[0044] Determine if charging has been paused or interrupted;

[0045] When charging is not interrupted, determine whether the remaining power of the energy storage system is less than the third preset value;

[0046] When the remaining power of the energy storage system is less than the third preset value, the available integrated bidirectional AC / DC module is locked according to the current power request.

[0047] The switching module connects the locked module to the vehicle to be charged for charging.

[0048] In an optional implementation, the method further includes:

[0049] When the current time is during the peak period of the power grid and the remaining power of the energy storage system is not greater than the second preset value, the available integrated bidirectional AC / DC module is locked according to the power request.

[0050] The switching module connects the locked module to the vehicle to be charged for charging.

[0051] In an optional implementation, the method further includes:

[0052] If the current time is not during the peak period of the power grid, lock the integrated bidirectional AC / DC module according to the power request;

[0053] The switching module connects the locked module to the vehicle to be charged for charging. Attached Figure Description

[0054] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a schematic block diagram of a semi-AC bus photovoltaic energy storage supercharging system according to an embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of a semi-AC bus photovoltaic-storage-supercharging system according to an embodiment of the present invention;

[0057] Figure 3 This is a schematic diagram of another half of the AC bus photovoltaic storage supercharging system according to an embodiment of the present invention;

[0058] Figure 4 This is a schematic diagram of a liquid cooling heat dissipation system according to an embodiment of the present invention;

[0059] Figure 5 This is a schematic flowchart of a semi-AC bus optical-storage-supercharging method according to an embodiment of the present invention;

[0060] Figure 6This is a control logic diagram of the semi-AC bus optical energy storage supercharging method according to an embodiment of the present invention;

[0061] Figure 7 This is a control logic diagram of another half of the AC bus optical-storage-supercharging method according to an embodiment of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] This invention provides a semi-AC bus photovoltaic-storage supercharging system. By employing an energy storage replenishment module, the charging and discharging of the energy storage system can be achieved, reducing the use of AC / DC modules, lowering system costs, and improving the charging efficiency of the energy storage system. Figure 1 As shown, the semi-AC bus photovoltaic-storage-supercharging system includes: an energy storage system, an energy storage replenishment module, a unidirectional isolated DC / DC module, multiple integrated bidirectional AC / DC modules, multiple switch modules, and multiple charging terminals. Among them, Figure 1 The example shown is a switch module using a full-matrix energy switching method.

[0064] Each integrated bidirectional AC / DC module has one end connected to a common AC bus, and at least one integrated bidirectional AC / DC module has its other end connected to one end of a switch module via an energy storage and power replenishment module. The other ends of the remaining integrated bidirectional AC / DC modules are directly connected to one end of the switch module, and the other end of the switch module is connected to the vehicle to be charged via a charging terminal. The energy storage system is connected to one end of the switch module via a unidirectional isolated DC / DC module. The energy storage system is connected between the integrated bidirectional AC / DC modules and the switch module via an energy storage and power replenishment module.

[0065] Specifically, the integrated bidirectional AC / DC module draws AC 380V power from the grid and converts it into DC power (200V-1000V) to charge the vehicle. Simultaneously, the vehicle can also feed its stored energy back to the grid via the integrated bidirectional AC / DC module. Each integrated bidirectional AC / DC module can be configured with a power output of 60-120kW, and multiple modules can be connected in parallel to form a 480kW or 600kW charging station. For example, using a 60kW integrated bidirectional AC / DC module, a 600kW charging station would require 10 such modules connected in parallel (some modules are omitted in the diagram). When a vehicle is plugged in for charging, the integrated bidirectional AC / DC module draws power from the grid, converting AC power into DC power to charge the vehicle. When the vehicle owner wishes to use the vehicle's lithium battery to feed back electricity to the grid and earn revenue, the integrated bidirectional AC / DC module converts the vehicle's DC power back into AC power, thus enabling V2G functionality.

[0066] The semi-AC bus photovoltaic-storage supercharging system features an energy storage system that can also be replenished via one or more integrated bidirectional AC / DC modules and energy storage replenishment modules, offering higher efficiency than AC bus solutions. The energy storage system can also charge vehicles via one or more unidirectional isolated DC / DC modules.

[0067] By adopting an integrated bidirectional AC / DC module and a unidirectional isolated DC / DC module, efficient transmission between the power grid, energy storage, photovoltaics, and charging terminals is achieved, greatly improving the charging and discharging efficiency of energy storage and photovoltaics.

[0068] In this embodiment of the invention, all power modules in the semi-AC bus photovoltaic-storage-supercharging system are fully liquid-cooled modules, which makes the power modules highly stable, have a long life cycle, low equipment noise, and strong environmental adaptability.

[0069] This invention provides a semi-AC bus photovoltaic-storage supercharging system. By employing an energy storage supplementary power module, the system can achieve charging and discharging of the energy storage system while reducing system costs. Compared with the existing AC scheme that directly charges the energy storage module through the grid, this scheme reduces the use of AC / DC modules, lowers system costs, and improves the charging efficiency of the energy storage module.

[0070] In one optional embodiment, the energy storage replenishment module includes at least one set of energy storage replenishment units, each set of energy storage replenishment units including a replenishment relay group Ki and a charging relay group Ki′, i = 1, 2…n. One end of the replenishment relay group Ki is connected to one end of the energy storage system, and the other end of the replenishment relay group Ki is connected to the other end of the integrated bidirectional AC / DC module and one end of the charging relay group Ki′; the other end of the charging relay group Ki′ is connected to one end of the switching module.

[0071] Specifically, the energy storage replenishment module is used as Figure 2 Let's take an example to demonstrate. Figure 2 The energy storage replenishment module includes two sets of energy storage replenishment units: energy storage replenishment unit 1 and energy storage replenishment unit 2. Energy storage replenishment unit 1 includes a replenishment relay group K1 and a charging relay group K1′. Energy storage replenishment unit 2 includes a replenishment relay group K2 and a charging relay group K2′. One end of the replenishment relay group K1 is connected to one end of the energy storage system, and the other end of the replenishment relay group K1 is connected to the other end of the integrated bidirectional AC / DC module m and one end of the charging relay group K1′; the other end of the charging relay group K1′ is connected to one end of the switching module. One end of the replenishment relay group K2 is connected to one end of the energy storage system, and the other end of the replenishment relay group K2 is connected to the other end of the integrated bidirectional AC / DC module n and one end of the charging relay group K2′; the other end of the charging relay group K2′ is connected to one end of the switching module.

[0072] In this embodiment of the invention, taking energy storage replenishment unit 1 as an example, when the integrated bidirectional AC / DC module x replenishes the energy storage system, the replenishment relay group K1 is closed and the charging relay group K1' is opened. The integrated bidirectional AC / DC module x converts the AC power into the DC power required by the energy storage system until the energy storage system is fully charged. After the energy storage system is fully replenished, the replenishment relay group K1 is opened and the charging relay group K1' is closed. When the system needs the energy storage system to participate in vehicle charging, the replenishment relay group K1 is opened and the charging relay group K1' is closed. The energy storage system charges the vehicle through the unidirectional isolated DC / DC module. The control strategy of energy storage replenishment unit 2 is the same as that of energy storage replenishment unit 1 and will not be described in detail here.

[0073] Furthermore, the replenishment relay group Ki contains two replenishment relays: one positive replenishment relay at the positive terminal of the energy storage system and one negative replenishment relay at the negative terminal. The charging relay group Ki′ also contains two charging relays: one positive charging relay at the positive terminal of the energy storage system and one negative charging relay at the negative terminal.

[0074] In one alternative implementation, the control logic of the supplementary power relay group and the control logic of the charging relay group are mutually exclusive.

[0075] Specifically, the charging relay group Ki and the recharge relay group Ki′ are designed with mutual exclusion in their hardware control; that is, the two relay groups cannot be closed simultaneously. This is because if both relay groups were closed at the same time, the vehicle's battery and the energy storage battery would be directly connected. This could potentially lead to the higher-voltage battery pack charging the lower-voltage battery pack due to voltage differences. Since both battery packs have very low internal resistance, this would result in a large charging current, which could burn out the fuses in the battery packs and cause a malfunction. Therefore, the control hardware circuits of the two relay groups are designed with mutual exclusion to avoid fuse burnout.

[0076] In existing charging stations, the integration of energy storage and charging stations can be achieved simply by adding a few relays. Compared to DC buses and semi-DC buses, the cost of energy storage integration has been minimized, significantly reducing the investment payback period for charging station customers. Furthermore, retrofitting existing charging stations with energy storage integration is also minimal in terms of difficulty and cost. The flexible switching of relays in the energy storage replenishment module greatly improves the charging and discharging efficiency of the energy storage battery, significantly enhancing the flexibility of energy storage access.

[0077] In one alternative implementation, the energy storage system includes at least one energy storage unit connected in parallel.

[0078] Specifically, when it is necessary to expand the capacity of an energy storage system, the following methods can be used: Method 1: Directly install multiple energy storage units and connect them in parallel to expand the capacity of the energy storage system. Method 2: Increase the number of energy storage replenishment units, wherein the connection point between the energy storage replenishment units and the energy storage system can be set on any unidirectional isolated DC / DC module and the energy storage system connection branch. In this embodiment of the invention, the number of unidirectional isolated DC / DC modules is determined according to the power of the energy storage system.

[0079] In one alternative implementation, such as Figure 1 and Figure 2 As shown, the semi-AC bus photovoltaic-storage-supercharging system also includes: a photovoltaic system and a photovoltaic inverter, wherein the photovoltaic system is connected to the common AC bus through the photovoltaic inverter.

[0080] Specifically, a semi-AC bus photovoltaic-storage-supercharging system includes several photovoltaic inverters; inverters of different power ratings can be selected based on project requirements. For example... Figure 2 The example shown only includes a single photovoltaic inverter. The main function of this inverter is to convert solar energy into electrical energy and feed it back into the power grid. It can also provide power for vehicle charging through an integrated bidirectional AC / DC module, thus improving photovoltaic utilization and preventing solar power curtailment.

[0081] The photovoltaic inverter includes AC / DC modules and single-phase DC / DC modules. The main function of the single-phase DC / DC module is to convert solar energy into direct current (DC). The AC / DC module converts DC into alternating current (AC) and connects it to the common AC bus for powering energy storage, powering charging piles, and feeding energy back to the grid.

[0082] In one alternative implementation, the switching module employs a full-matrix energy switching method or a half-matrix energy switching method.

[0083] Specifically, the function of the switch module is to distribute the energy of the power module. Through the relay switching combination in the switch module, each charging terminal can have the function of full power output, and users can enjoy supercharging service at any charging station.

[0084] in, Figure 2 This is a schematic diagram illustrating the full-matrix energy switching method used in the switching module. Figure 3 This diagram illustrates the use of a half-matrix energy switching method in the switching module. When employing this method, the relay switching combination within the charging pile's half-matrix PDU module enables each charging terminal to output full power, allowing users to enjoy fast charging services from any parking space. Each charging pile half-matrix PDU module connects to half of the AC / DC module and half of the DC / DC module, thus allowing each module to output half of the charging system's power.

[0085] In one alternative implementation, the semi-AC bus photovoltaic-storage-supercharging system further includes a liquid cooling system, which exchanges heat with the unidirectional isolated DC / DC module, the photovoltaic inverter, and each integrated bidirectional AC / DC module through the refrigerant in the liquid cooling pipeline.

[0086] Specifically, the liquid cooling system provides cooling for the power modules. Heat from the unidirectional isolated DC / DC modules, photovoltaic inverters, and each integrated bidirectional AC / DC module is transferred to the liquid cooling system via refrigerant in the liquid cooling pipes. The liquid cooling system then uses fans to conduct the heat to the external environment, thereby achieving the purpose of cooling the power modules. A specific liquid cooling system is as follows: Figure 4As shown. The liquid cooling system uses heat sinks for external heat dissipation, transferring the heated coolant to the heat sinks, and then a fan blows the heat out of the enclosure. The heat sink fan uses intelligent control and has three operating modes: low, medium, and high. When the power of the half-AC bus photovoltaic-storage-supercharging system is less than one-third of the total power, the fan operates at low speed; when the power of the half-AC bus photovoltaic-storage-supercharging system is greater than one-third but less than two-thirds of the total system power, the fan operates at medium speed; and when the power of the half-AC bus photovoltaic-storage-supercharging system is greater than two-thirds, the fan operates at high speed. This detailed fan operating mode further reduces system energy consumption.

[0087] Employing an integrated bidirectional liquid-cooled AC / DC module, a unidirectional liquid-cooled isolated DC / DC module, and a matching liquid-cooling heat dissipation system, this system offers improved stability and lifespan compared to air-cooled power cabinets on the market. It significantly reduces system power consumption and operating noise, enhances the equipment's environmental adaptability, and simplifies maintenance. The liquid-cooling heat dissipation system utilizes intelligent fan control, adjusting fan operating modes based on system power levels to further reduce system power consumption.

[0088] In one alternative implementation, such as Figure 2 As shown, the integrated bidirectional AC / DC module includes an AC / DC module and an isolated DC / DC module.

[0089] Specifically, all integrated bidirectional AC / DC modules operate in a single mode, namely constant current mode. They can replenish power to the vehicle and energy storage battery without changing the module's operating mode, because for the module, the vehicle's battery and the energy storage battery are the same, only the battery voltage and capacity are different.

[0090] In one alternative implementation, each charging terminal is liquid-cooled.

[0091] Specifically, each charging terminal employs an oil-cooling system, effectively reducing the weight of the charging gun and cable, making it easy for every user to plug and unplug the charging gun. The liquid-cooled terminal cable is capable of handling over 600A of current, meaning the gun has a charging power capacity of nearly 600kW, meeting the supercharging power requirements of over 99% of vehicles on the market.

[0092] By using fully liquid-cooled charging terminals, the charging cable grabbing is lighter, making it easier for customers to grab a Supercharger cable and making the Supercharger system more user-friendly.

[0093] This invention provides a semi-AC bus photovoltaic-storage-supercharging method, based on the aforementioned semi-AC bus photovoltaic-storage-supercharging system, such as... Figure 5 As shown, the semi-AC bus photovoltaic-storage-supercharging method includes:

[0094] Step S101: When it is necessary to replenish the energy storage system, lock the callable integrated bidirectional AC / DC module according to the power to be replenished, disconnect the charging relay group connected to the callable integrated bidirectional AC / DC module, close the replenishment relay group connected to the callable integrated bidirectional AC / DC module, and use the integrated bidirectional AC / DC module to replenish the energy storage system.

[0095] Specifically, during the operation of the semi-AC bus photovoltaic-storage supercharging system, it is determined whether the energy storage system needs to be recharged. When it is determined that the energy storage system needs to be recharged, a callable integrated bidirectional AC / DC module is locked based on the power to be recharged. Then, the charging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the recharge relay group connected to the callable integrated bidirectional AC / DC module is closed, the locked module and the energy storage system are connected, the connection between the locked module and the switching module is disconnected, and the integrated bidirectional AC / DC module is used to recharge the energy storage system.

[0096] Step S102: When it is not necessary to replenish the energy storage system, disconnect the replenishment relay group connected to the callable integrated bidirectional AC / DC module and close the charging relay group connected to the callable integrated bidirectional AC / DC module.

[0097] Specifically, when it is determined that no power replenishment is needed for the energy storage system, the power replenishment relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the charging relay group connected to the callable integrated bidirectional AC / DC module is closed, the connection between the callable module and the energy storage system is disconnected, and the connection between the callable module and the switch module is connected.

[0098] This invention provides a semi-AC bus photovoltaic-storage supercharging method. By using an energy storage supplementary power module, the system cost is reduced while the energy storage system is charged and discharged. Compared with the existing AC scheme that directly charges the energy storage module through the grid, this scheme reduces the use of AC / DC modules, lowers the system cost, and improves the charging efficiency of the energy storage module.

[0099] In one optional implementation, when the energy storage system needs to be recharged, an available integrated bidirectional AC / DC module is locked according to the power to be recharged, including:

[0100] Step S1011: Determine whether the current time is during a power grid off-peak period.

[0101] Step S1012: When the current time is during a grid off-peak period, determine whether the remaining power of the energy storage system is not greater than the first preset value.

[0102] Step S1013: When the current time is during a grid off-peak period and the remaining power of the energy storage system is not greater than the first preset value, obtain the power to be replenished, and lock the callable integrated bidirectional AC / DC module according to the power to be replenished request.

[0103] Specifically, when determining whether to recharge the energy storage system, the first step is to determine if the current time is during a grid off-peak period. If so, the system's remaining charge is checked to see if it is ≤98% of its State of Charge (SOC). If so, the system determines if an integrated bidirectional AC / DC module capable of recharging the system is available. If the module is available, the system further assesses its own operational status and charging capability. If the system is operating normally and charging is possible, the available integrated bidirectional AC / DC module is selected based on the required recharge power. By utilizing energy storage for peak shaving and valley filling, the energy storage cost of the semi-AC bus photovoltaic-storage supercharging system is reduced.

[0104] In an optional implementation, step S102 includes:

[0105] Step S1021: Determine whether the charging of the energy storage system is interrupted or terminated, and whether the energy storage system needs to participate in vehicle charging.

[0106] Step S1022: When the energy storage system charging is interrupted, charging ends, or the energy storage system needs to participate in vehicle charging, disconnect the charging relay group connected to the callable integrated bidirectional AC / DC module and close the charging relay group connected to the callable integrated bidirectional AC / DC module.

[0107] Specifically, when determining that no recharging of the energy storage system is needed, the process first checks whether the energy storage system's charging is interrupted. If the energy storage system's charging is interrupted, the recharging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the charging relay group connected to the callable integrated bidirectional AC / DC module is closed, the connection between the callable module and the energy storage system is disconnected, and the connection between the callable module and the switch module is connected. If the energy storage system's charging is not interrupted, the process checks whether the energy storage system has finished charging. If the energy storage system has finished charging, the recharging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, and the charging relay group connected to the callable integrated bidirectional AC / DC module is closed. If the energy storage system has not finished charging, the process checks again whether the current time is during a grid off-peak period. If the current time is during a grid off-peak period, the energy storage recharging operation continues. If the current time is not during a grid off-peak period, the recharging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the charging relay group connected to the callable integrated bidirectional AC / DC module is closed, and the energy storage recharging ends.

[0108] Furthermore, when the energy storage system is required to participate in vehicle charging, the energy storage replenishment operation is no longer performed. That is, at this time, the replenishment relay group connected to the callable integrated bidirectional AC / DC module is disconnected, and the charging relay group connected to the callable integrated bidirectional AC / DC module is closed. See the control logic diagram for energy storage replenishment. Figure 6 .

[0109] In one optional implementation, the semi-AC bus photovoltaic-storage-supercharging method further includes:

[0110] Step S201: When a power request is received from a vehicle to be charged, determine whether the current time is during the peak period of the power grid.

[0111] Step S202: When the current time is during the peak period of the power grid, determine whether the remaining power of the energy storage system is greater than the second preset value.

[0112] Step S203: When the current time is during the peak period of the power grid and the remaining power of the energy storage system is greater than the second preset value, lock the available integrated bidirectional AC / DC module and unidirectional isolated DC / DC module according to the power request.

[0113] Step S204: Switch the module to connect the locked module to the vehicle to be charged for charging.

[0114] Specifically, the control logic for energy storage discharge is as follows: Figure 7 As shown, when a vehicle needs charging, the user unplugs the charging gun from the charging pile and inserts it into the charging port of the vehicle to be charged, ensuring a secure connection between the charging cable and the vehicle. After the vehicle is connected to the charging pile terminal, the system receives a power request from the vehicle and then determines if the current time is during peak grid hours. If it is, the system checks if the remaining capacity of the energy storage system in the semi-AC bus photovoltaic-storage supercharging system is greater than 50% of its state of charge (SOC). If both are during peak hours and the remaining capacity is greater than 50%, the system locks down available integrated bidirectional AC / DC modules and unidirectional isolated DC / DC modules based on the power request from the vehicle. The switching module connects the locked modules to the vehicle being charged.

[0115] In one optional implementation, the semi-AC bus photovoltaic-storage-supercharging method further includes:

[0116] Step S205: Determine whether charging has been paused or interrupted.

[0117] Step S206: When charging is not interrupted, determine whether the remaining power of the energy storage system is less than the third preset value.

[0118] Step S207: When the remaining power of the energy storage system is less than the third preset value, lock the available integrated bidirectional AC / DC module according to the current power request.

[0119] Step S208: Switch the module to connect the locked module to the vehicle to be charged for charging.

[0120] Specifically, after connecting the locked module and the vehicle to be charged, charging is initiated. During charging, the charging status needs to be monitored periodically to determine if charging has been interrupted. When charging is detected as not interrupted, it is determined whether the remaining power of the energy storage system is less than 5% of its State of Charge (SOC). If the remaining power of the energy storage system is less than 5% of its SOC, it indicates that the energy storage system's power is too low to charge the vehicle normally. If charging is not yet complete, the switch in the switching module is disconnected to stop using the energy storage system and photovoltaic system to charge the vehicle, and grid power is selected to charge the vehicle. Specifically, the current power request of the vehicle to be charged is obtained through querying. Based on the current power request, an available integrated bidirectional AC / DC module is locked, the switching module is re-switched, the locked module and the vehicle to be charged are connected, and grid power is used to charge the vehicle. During charging, if a charging interruption is detected, it is determined whether to end charging. If it is determined that charging needs to be ended, the switch in the switching module is disconnected to end charging. If it is determined that charging should continue, it is determined whether to restart charging. If it is determined that charging needs to be restarted, charging is restarted according to the previous charging path. If it is determined that charging does not need to be restarted, return to the step of determining whether to end charging.

[0121] When the remaining power of the energy storage system is not less than 5% SOC, it is determined whether charging is complete. If charging is complete, the switch in the switching module is disconnected; if charging is incomplete, charging continues.

[0122] In one optional implementation, the semi-AC bus photovoltaic-storage-supercharging method further includes:

[0123] Step S209: When the current time is during the peak period of the power grid and the remaining power of the energy storage system is not greater than the second preset value, lock the available integrated bidirectional AC / DC module according to the power request.

[0124] Step S210: Switch the module to connect the locked module to the vehicle to be charged for charging.

[0125] Specifically, when the current time is during the grid peak period and the remaining power of the energy storage system is no more than 50% of its State of Charge (SOC), it indicates that the energy storage system's power is insufficient to charge the vehicle, and the grid power supply method is selected to charge the vehicle. Specifically, based on the power request sent by the vehicle to be charged, an available integrated bidirectional AC / DC module is locked, the switching module is re-connected, and the locked module and the vehicle to be charged are connected, utilizing both grid and photovoltaic power supply methods to charge the vehicle.

[0126] In one optional implementation, the semi-AC bus photovoltaic-storage-supercharging method further includes:

[0127] Step S211: When the current time is not during the peak period of the power grid, lock the integrated bidirectional AC / DC module according to the power request.

[0128] Step S212: Switch the module to connect the locked module to the vehicle to be charged for charging.

[0129] Specifically, when the current time is not during the peak period of the power grid, the vehicle is charged directly using the grid power supply method. Based on the power request sent by the vehicle to be charged, an available integrated bidirectional AC / DC module is locked, the switching module is switched on and off, the locked integrated bidirectional AC / DC module and the vehicle to be charged are connected, and the vehicle is charged using the grid power supply method.

[0130] Similarly, during charging, the system monitors whether charging is paused. If a charging pause is detected, it determines whether to end charging. If it determines that charging needs to be ended, the switch in the switching module is disconnected, and charging ends. If it determines that charging should continue, it determines whether to restart charging. If it determines that charging needs to be restarted, charging restarts according to the previous charging path. If it determines that charging does not need to be restarted, it returns to the step of determining whether to end charging. If a charging pause is detected without interruption, it determines whether charging is complete. If it determines that charging is complete, the switch in the switching module is disconnected, and charging ends. If it determines that charging is not complete, it continues charging according to the previous charging path.

[0131] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A semi-AC bus photovoltaic-storage-supercharging system, characterized in that, The system includes: an energy storage system, an energy storage and replenishment module, a unidirectional isolated DC / DC module, multiple integrated bidirectional AC / DC modules, multiple switch modules, and multiple charging terminals, wherein... One end of each of the integrated bidirectional AC / DC modules is connected to a common AC bus, and the other end of at least one of the integrated bidirectional AC / DC modules is connected to one end of the switch module through the energy storage and power replenishment module. The other ends of the remaining integrated bidirectional AC / DC modules are directly connected to one end of the switch module, and the other end of the switch module is connected to the vehicle to be charged through a charging terminal. The energy storage system is connected to one end of the switching module through the unidirectional isolated DC / DC module. The energy storage system is connected between the integrated bidirectional AC / DC module and the switch module through the energy storage and power replenishment module.

2. The semi-AC bus photovoltaic-storage-supercharging system according to claim 1, characterized in that, The energy storage and replenishment module includes at least one set of energy storage and replenishment units, and each set of energy storage and replenishment units includes a replenishment relay group and a charging relay group, wherein... One end of the power replenishment relay group is connected to one end of the energy storage system, and the other end of the power replenishment relay group is connected to the other end of the integrated bidirectional AC / DC module and one end of the charging relay group, respectively. The other end of the charging relay group is connected to one end of the switch module.

3. The semi-AC bus photovoltaic-storage-supercharging system according to claim 2, characterized in that, The control logic of the replenishment relay group and the control logic of the charging relay group are mutually exclusive.

4. The semi-AC bus photovoltaic-storage-supercharging system according to claim 1, characterized in that, The energy storage system includes at least one energy storage unit, which is connected in parallel.

5. The semi-AC bus photovoltaic-storage-supercharging system according to claim 1, characterized in that, The system also includes: a photovoltaic system and a photovoltaic inverter, wherein, The photovoltaic system is connected to the common AC bus via the photovoltaic inverter.

6. The semi-AC bus photovoltaic-storage-supercharging system according to claim 1, characterized in that, The switching module adopts either a full-matrix energy switching method or a half-matrix energy switching method.

7. The semi-AC bus photovoltaic-storage-supercharging system according to claim 5, characterized in that, The system also includes a liquid cooling system, which exchanges heat with the unidirectional isolated DC / DC module, the photovoltaic inverter, and each of the integrated bidirectional AC / DC modules through the refrigerant in the liquid cooling pipeline.

8. A semi-AC bus photovoltaic-storage-supercharging method, characterized in that, Based on the semi-AC bus photovoltaic-storage-supercharging system according to any one of claims 1-7, the method includes: When the energy storage system needs to be recharged, the callable integrated bidirectional AC / DC module is locked according to the power to be recharged, the charging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, the recharge relay group connected to the callable integrated bidirectional AC / DC module is closed, and the integrated bidirectional AC / DC module is used to recharge the energy storage system. When it is not necessary to recharge the energy storage system, disconnect the recharge relay group connected to the callable integrated bidirectional AC / DC module and close the charging relay group connected to the callable integrated bidirectional AC / DC module.

9. The semi-AC bus photovoltaic-storage-supercharging method according to claim 8, characterized in that, When the energy storage system needs to be recharged, the system locks down an available integrated bidirectional AC / DC module based on the power to be recharged, including: Determine if the current time is during a power grid off-peak period; When the current time is during a grid off-peak period, determine whether the remaining power of the energy storage system is not greater than a first preset value; When the current time is during a grid off-peak period and the remaining power of the energy storage system is not greater than a first preset value, the power to be replenished is obtained, and the callable integrated bidirectional AC / DC module is locked according to the power to be replenished.

10. The semi-AC bus photovoltaic-storage-supercharging method according to claim 9, characterized in that, When it is not necessary to replenish the energy storage system, disconnecting the replenishment relay group connected to the callable integrated bidirectional AC / DC module and closing the charging relay group connected to the callable integrated bidirectional AC / DC module includes: Determine whether the energy storage system charging is interrupted or terminated, and whether the energy storage system needs to participate in vehicle charging; When the energy storage system's charging is interrupted, charging ends, or the energy storage system needs to participate in vehicle charging, the charging relay group connected to the callable integrated bidirectional AC / DC module is disconnected, and the charging relay group connected to the callable integrated bidirectional AC / DC module is closed.

11. The semi-AC bus photovoltaic-storage-supercharging method according to claim 8, characterized in that, The method further includes: When a power request is received from a vehicle to be charged, it is determined whether the current time is during the peak period of the power grid. When the current time is during the peak period of the power grid, determine whether the remaining power of the energy storage system is greater than the second preset value; When the current time is during the peak period of the power grid and the remaining power of the energy storage system is greater than the second preset value, the available integrated bidirectional AC / DC module and unidirectional isolated DC / DC module are locked according to the power request. The switching module connects the locked module to the vehicle to be charged for charging.

12. The semi-AC bus photovoltaic-storage-supercharging method according to claim 11, characterized in that, The method further includes: Determine if charging has been paused or interrupted; When charging is not interrupted, determine whether the remaining power of the energy storage system is less than the third preset value; When the remaining power of the energy storage system is less than the third preset value, the available integrated bidirectional AC / DC module is locked according to the current power request. The switching module connects the locked module to the vehicle to be charged for charging.

13. The semi-AC bus photovoltaic-storage-supercharging method according to claim 11, characterized in that, The method further includes: When the current time is during the peak period of the power grid and the remaining power of the energy storage system is not greater than the second preset value, the available integrated bidirectional AC / DC module is locked according to the power request. The switching module connects the locked module to the vehicle to be charged for charging.

14. The semi-AC bus photovoltaic-storage-supercharging method according to claim 11, characterized in that, The method further includes: If the current time is not during the peak period of the power grid, lock the integrated bidirectional AC / DC module according to the power request; The switching module connects the locked module to the vehicle to be charged for charging.

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