A light storage and charging fusion system and charging method

Abstract

The present invention discloses a photovoltaic storage and charging fusion system and a charging method; the present invention comprises a photovoltaic storage hybrid inverter, a photovoltaic power component, a dual-channel PCS and a battery system; the input side DC in the dual-channel PCS is connected to the battery system, the output side DC is connected to the charging station system, and the AC is connected to the power grid; the PV side in the photovoltaic storage and charging hybrid inverter is connected to the photovoltaic power component, the output side DC is connected to the charging station system, and the AC is connected to the power grid; the photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both communicatively connected to the photovoltaic storage and charging system, and the dual-channel PCS is communicatively connected to the battery system; the charging of the charging station system and the charging and discharging operation of the battery can be supported simultaneously without using the mains power. When there is no vehicle for charging, the storage and charging circuit supplies power to the photovoltaic storage and charging circuit to assist the photovoltaic stable grid-connected discharge power operation function, which can effectively solve the problem of photovoltaic abandoned light with a DC coupled architecture.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic storage charging and testing technology, and in particular to a photovoltaic storage charging fusion system and a charging method. Background Art

[0002] At present, energy storage batteries are following the development path of power batteries. When the capacity of power batteries develops towards ultra-large capacity, the development direction of energy storage batteries is also developing. The current photovoltaic storage and charging system is composed of a DC coupling system. Its advantage is that the battery in the system can be used as the main source of charging energy support, reducing dependence on the power grid, while reducing the impact of orderly and disorderly charging on the power grid, and reducing the impact on the power grid.

[0003] However, as battery capacity increases, the demand for photovoltaic power increases in order to reduce dependence on the power grid. The photovoltaic storage and charging system prioritizes ensuring that the battery does not discharge when fully charged, and when there is no car charging, the photovoltaic is connected to the storage, charging and inspection system by DC coupling, resulting in abandoned light. In order to avoid abandoned light, reducing photovoltaic installed capacity will affect the battery charging time, and at the same time, problems such as fast power consumption at the charging station and long charging time will occur. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a photovoltaic storage and charging fusion system and a charging method to solve the problem of photovoltaic abandonment in a DC coupled architecture.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A photovoltaic storage and charging fusion system, including a photovoltaic storage hybrid inverter, a photovoltaic power module, a dual-channel PCS and a battery system;

[0007] The input side DC in the dual-channel PCS is connected to the battery system, the output side DC is connected to the charging station system, and the AC is connected to the power grid;

[0008] The PV side of the photovoltaic storage and charging hybrid inverter is connected to the photovoltaic power component, the output DC side is connected to the charging station system, and the AC side is connected to the power grid;

[0009] The photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both communicatively connected to the photovoltaic storage and charging system, and the dual-channel PCS is communicatively connected to the battery system.

[0010] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0011] A photovoltaic storage and charging fusion charging method is based on the photovoltaic storage and charging fusion system described above, and includes the following steps:

[0012] S1. Determine whether there is a vehicle charging demand in the charging station system. If yes, proceed to step S2; otherwise, proceed to step S3;

[0013] S2. Determine the battery SOC. If the battery SOC is greater than a preset first threshold, the battery system will give priority to providing power to the charging station system. Otherwise, the photovoltaic power module and the battery system will give priority to providing power to the charging station system.

[0014] S3. The battery SOC is judged. If the battery SOC is greater than a preset second threshold, the battery system assists the photovoltaic power component to stably connect to the grid for power generation. Otherwise, the photovoltaic power component is discharged first, and the battery system does not participate in the regulation.

[0015] The beneficial effects of the present invention are as follows: a photovoltaic storage and charging fusion system and a charging method of the present invention are equipped with a photovoltaic storage and charging circuit, which can independently use photovoltaic power generation to charge the battery and the charging station system through a photovoltaic storage hybrid inverter. At the same time, the storage and charging circuit can also independently use the mains power to charge and discharge the battery and the charging station system; it can simultaneously support the charging of the charging station system and the charging and discharging of the battery without using the mains power. When there is no vehicle charging, the storage and charging circuit supplies power to the photovoltaic storage and charging circuit to assist the photovoltaic stable grid-connected discharge power operation function, which can effectively solve the problem of photovoltaic abandonment with a DC coupling architecture; at the same time, it can assist in solving the problem of the impact of the unstable power generation characteristics of the photovoltaic system on the mains, which is more friendly to the power grid and can play a certain supporting role; wherein the charging circuit of the dual-channel PCS and the hybrid inverter connected to the charging station system is independent and is not affected by the battery voltage. The output voltage can be set higher to improve the charging efficiency of the charging station. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the architecture of a photovoltaic storage and charging fusion system according to an embodiment of the present invention;

[0017] Figure 2 This is an example flow chart of a charging method for integrating light storage and charging according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0019] Please refer to Figure 1 , a photovoltaic storage and charging fusion system, including a photovoltaic storage hybrid inverter, a photovoltaic power module, a dual-channel PCS and a battery system;

[0020] The input side DC in the dual-channel PCS is connected to the battery system, the output side DC is connected to the charging station system, and the AC is connected to the power grid;

[0021] The PV side of the photovoltaic storage and charging hybrid inverter is connected to the photovoltaic power component, the output DC side is connected to the charging station system, and the AC side is connected to the power grid;

[0022] The photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both communicatively connected to the photovoltaic storage and charging system, and the dual-channel PCS is communicatively connected to the battery system.

[0023] From the above description, it can be seen that the beneficial effects of the present invention are: a photovoltaic storage and charging fusion system of the present invention is equipped with a photovoltaic storage and charging circuit, which can independently use photovoltaic power generation to charge the battery and the charging station system through a photovoltaic storage hybrid inverter. At the same time, the storage and charging circuit can also independently use the mains power to charge and discharge the battery and the charging station system; it can support the charging of the charging station system and the battery charging and discharging operation without using the mains power. When there is no car charging, the storage and charging circuit supplies power to the photovoltaic storage and charging circuit to assist the photovoltaic stable grid-connected discharge power operation function, which can effectively solve the problem of photovoltaic abandonment with a DC coupling architecture; at the same time, it can assist in solving the problem of the impact of the unstable power generation characteristics of the photovoltaic system on the mains, which is more friendly to the power grid and can play a certain supporting role; wherein the charging circuit of the dual-channel PCS and the hybrid inverter connected to the charging station system is independent, not affected by the battery voltage, and the output voltage can be set higher to improve the charging efficiency of the charging station.

[0024] Furthermore, the photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both connected to the photovoltaic storage and charging system 485 via communication, and the dual-channel PCS is connected to the battery system via CAN communication.

[0025] It can be seen from the above description that the above is a specific embodiment of the communication connection relationship in a photovoltaic storage and charging fusion system.

[0026] Please refer to Figure 2 A photovoltaic storage and charging fusion charging method is based on the photovoltaic storage and charging fusion system described above and includes the following steps:

[0027] S1. Determine whether there is a vehicle charging demand in the charging station system. If yes, proceed to step S2; otherwise, proceed to step S3;

[0028] S2. Determine the battery SOC. If the battery SOC is greater than a preset first threshold, the battery system will give priority to providing power to the charging station system. Otherwise, the photovoltaic power module and the battery system will give priority to providing power to the charging station system.

[0029] S3. The battery SOC is judged. If the battery SOC is greater than a preset second threshold, the battery system assists the photovoltaic power component to stably connect to the grid for power generation. Otherwise, the photovoltaic power component is discharged first, and the battery system does not participate in the regulation.

[0030] From the above description, it can be seen that the beneficial effects of the present invention are: a charging method that integrates light storage and charging of the present invention can support charging of the charging station system and battery charging and discharging operation at the same time without using the mains power. When there is no car to charge, the battery system assists the photovoltaic power components to stabilize the grid-connected power generation and assists the photovoltaic power components to stabilize the grid-connected discharge power operation function, which can effectively solve the problem of abandoned light in the photovoltaic DC-coupled architecture; at the same time, it can assist in solving the problem of the impact of the unstable power generation characteristics of the photovoltaic system on the mains, which is more friendly to the power grid and can play a certain supporting role.

[0031] Furthermore, in step S2, the battery system is preferentially used to provide power to the charging station system as follows:

[0032] The battery system is the first priority, and the photovoltaic power module is the second priority to provide power for the charging station system, wherein the photovoltaic power module provides supplementary power for the battery system, and then realizes the power dynamic balance strategy.

[0033] From the above description, it can be seen that it supports not using AC power. When the battery SOC of the battery system is relatively sufficient, taking into account the intermittent, interrupted and unstable power characteristics of photovoltaics, it can only play a balancing role. At the same time, in order to effectively reduce the battery power output, reflect the photovoltaic energy replenishment effect, and reduce the battery in a constant power output state, the battery system is given priority to provide stable power support for the charging station system, and the photovoltaic power components are used as supplementary power to meet the charging needs of quickly establishing stable output. After charging is established, the charging power balance is maintained through the power dynamic balancing strategy.

[0034] Furthermore, the power dynamic balancing strategy is specifically as follows:

[0035] The photovoltaic power components are taken as the first priority and the battery system is taken as the second priority to provide power for the charging station system, wherein the battery system provides supplementary power for the photovoltaic power components.

[0036] From the above description, it can be seen that when performing power balancing, photovoltaic power is used first, and battery power plays a stabilizing and regulating role.

[0037] Furthermore, in step S2, the photovoltaic power assembly and the battery system are preferentially used to provide power to the charging station system, specifically:

[0038] With photovoltaic power as the first priority and battery system as the second priority, power is provided to the charging station system;

[0039] When the power demand of the charging station system is greater than the sum of the power of the photovoltaic power components and the battery system, if the photovoltaic power meets the preset instability judgment condition, the power provided to the charging station system is reduced or stopped.

[0040] From the above description, it can be seen that it supports not using AC power. When the battery SOC of the battery system is not sufficient, photovoltaic power is prioritized, and the battery power plays a stabilizing and regulating role to provide power for the charging station system. When the photovoltaic power is unstable, the charging power can be lowered or charging can be stopped to form effective protection.

[0041] Furthermore, in step S3, the battery system assists the photovoltaic power assembly to stabilize the grid-connected power generation as follows:

[0042] The photovoltaic power components are given the first priority, and the battery system is given the second priority to provide power to the mains, wherein the battery system provides supplementary power for the photovoltaic power components.

[0043] From the above description, it can be seen that when there is no car charging and the battery SOC is relatively sufficient, the storage and charging circuit supplies power to the photo-storage and charging circuit to assist the photovoltaic stable grid-connected power generation power operation strategy. The photovoltaic power is defined as the priority discharge power, which is defined as the first priority, and the battery power is defined as the dynamic adjustment power, which is defined as the second priority.

[0044] Furthermore, in step S3, the photovoltaic power components are discharged first, and the battery system does not participate in the regulation. Specifically,

[0045] The photovoltaic power components discharge first to provide power to the mains, and the battery system does not participate in the regulation;

[0046] When the mains power is less than a first preset ratio of the photovoltaic-storage hybrid inverter power, and the power of the photovoltaic power component is greater than a second preset ratio of the photovoltaic-storage hybrid inverter power, if the photovoltaic power meets the preset instability judgment conditions, the grid-connected power generation power provided to the mains is reduced, or the grid-connected power generation power provided to the mains is stopped.

[0047] From the above description, it can be seen that when there is no car charging and the battery SOC is not sufficient, the photovoltaic power is defined as the priority discharge power, which is the first priority. The battery system does not participate in dynamic adjustment. If the photovoltaic power is unstable, it is necessary to lower the grid-connected discharge power or stop charging for protection.

[0048] The present invention provides a photovoltaic storage and charging fusion system and a charging method, which are suitable for the scenario of charging new energy vehicles.

[0049] Please refer to Figure 1 , Embodiment 1 of the present invention is:

[0050] A photovoltaic storage and charging fusion system, including a photovoltaic storage hybrid inverter, a photovoltaic power module, a dual-channel PCS and a battery system;

[0051] The input side DC in the dual-path PCS is connected to the battery system, the output side DC is connected to the charging station system, and the AC is connected to the power grid.

[0052] In this embodiment, there are two PCSs, one input side DC1 can input a high voltage wide range battery system, and the battery system is composed of a battery cabinet; one output side DC2 can output a high voltage wide range DC voltage to the charging station system, and the charging station system is composed of DCDC+charging piles; the mains side of the two PCSs is connected to the power grid.

[0053] Figure 1 In the figure, bat means battery system.

[0054] The dual-channel PCS provides power for the connected charging system and is compatible with different voltage levels and the highest efficiency voltage point, improving the compatibility with the charging system and achieving the best efficiency. When the PCS is off-grid and loses grid support, it needs to replenish energy and can obtain energy from the output side of the photovoltaic storage hybrid to avoid battery feeding.

[0055] The PV side of the photovoltaic storage and charging hybrid inverter is connected to the photovoltaic power component, the output DC side is connected to the charging station system, and the AC side is connected to the power grid.

[0056] In this embodiment, the photovoltaic hybrid inverter adopts a high-voltage grid-connected inverter. The photovoltaic side of the photovoltaic hybrid inverter has photovoltaic power components that can be connected to a high voltage and a wide range, and the photovoltaic power components are composed of mainstream power components; the output DC side of the photovoltaic hybrid inverter can output high-voltage DC voltage to the charging system, and the charging station system is composed of DCDC+charging piles; the mains side of the photovoltaic hybrid inverter is directly connected to the power grid.

[0057] The photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both connected to the photovoltaic storage and charging system in communication, and the dual-channel PCS is connected to the battery system in communication. Specifically, the photovoltaic storage and charging hybrid inverter and the dual-channel PCS are both connected to the photovoltaic storage and charging system 485 in communication, and the dual-channel PCS is connected to the battery system in CAN communication.

[0058] In this embodiment, the photovoltaic storage hybrid inverter communicates with the photovoltaic storage charging system EMS through 485 communication, and is monitored and controlled by the photovoltaic storage charging system EMS. The dual-channel PCS has CAN communication and 485 communication, communicates with the battery through CAN communication, monitors and controls the battery status information, and communicates with the photovoltaic storage charging system EMS through 485 communication, and is monitored and controlled by the EMS.

[0059] In this embodiment, two circuits, namely, light storage and charging and storage charging, can be formed based on the above components.

[0060] Among them, the photovoltaic storage and charging circuit consists of: photovoltaic storage hybrid inverter, photovoltaic power components, charging station system, dual-channel PCS DC input side DC1, and output side DC2.

[0061] The photovoltaic storage and charging circuit is connected as follows: the photovoltaic power component is connected to the PV side of the photovoltaic storage hybrid inverter to provide photovoltaic power; the output DC side of the photovoltaic storage hybrid inverter is connected to the input side of the charging system to provide power to the charging station system, and is also connected to the DC output DC2 of the storage and charging circuit to provide power, which can be used to convert and charge the battery system; the AC power end of the photovoltaic storage hybrid inverter is connected to the AC power to provide / receive power to the grid.

[0062] Storage and charging circuit composition: dual-channel PCS, charging system, and photovoltaic storage hybrid inverter.

[0063] The storage and charging circuits are connected as follows: the dual-channel PCS input side DC1 is connected to the battery to provide and receive power to the battery; the dual-channel PCS output side DC2 is connected to the charging system input side to directly provide power to the charging station system; the output DC side of the photovoltaic storage hybrid inverter is connected to the charging system input side, and is also connected to the storage and charging circuit DC output DC2 to provide power, while converting and charging the battery and the battery system.

[0064] The dual-channel PCS mains terminal is connected to the mains to provide / receive power to the grid.

[0065] Please refer to Figure 2 A photovoltaic storage and charging fusion charging method is based on the photovoltaic storage and charging fusion system described in the first embodiment above, and includes the following steps:

[0066] S1. Determine whether there is a vehicle charging demand in the charging station system. If yes, proceed to step S2; otherwise, proceed to step S3.

[0067] A photovoltaic storage and charging fusion system based on the above embodiment 1 can achieve the following functions:

[0068] (1) Implement an operation strategy that allows the photovoltaic power generation circuit to independently use photovoltaic power generation and use a photovoltaic power storage hybrid inverter to charge the battery and the charging station system.

[0069] (2) Realize the operation strategy of independent use of mains power by the storage and charging circuit to charge and discharge the battery and charge the charging station system.

[0070] (3) Implement an operating strategy for charging the charging station system and charging and discharging the battery system without using AC power.

[0071] (4) When there is no vehicle charging, the storage and charging circuit supplies power to the photovoltaic storage and charging circuit to assist the photovoltaic power generation to stabilize the grid-connected discharge power.

[0072] In this embodiment, functions (3) and (4) are mainly described, and functions (3) and (4) are distinguished based on whether there is a vehicle charging demand.

[0073] S2. Determine the battery SOC. If the battery SOC is greater than a preset first threshold, the battery system will give priority to providing power to the charging station system. Otherwise, the photovoltaic power module and the battery system will give priority to providing power to the charging station system.

[0074] In step S2, the battery system preferentially provides power to the charging station system as follows:

[0075] The battery system is the first priority, and the photovoltaic power module is the second priority, providing power for the charging station system, wherein the photovoltaic power module provides supplementary power for the battery system, and then realizes the power dynamic balance strategy;

[0076] The power dynamic balancing strategy is specifically as follows:

[0077] The photovoltaic power components are taken as the first priority and the battery system is taken as the second priority to provide power for the charging station system, wherein the battery system provides supplementary power for the photovoltaic power components.

[0078] In this embodiment, the first threshold is 30%, and in other equivalent embodiments, it can be adjusted according to actual conditions.

[0079] In this embodiment, in the scenario where there is no vehicle charging demand, when the battery SOC is greater than 30%, the battery will preferentially provide power to the charging station system. And the following judgment is made:

[0080] (1) Pcharge ≥ Ppv:

[0081] Execute the charging system demand generation strategy:

[0082] Pcharge=Pbat+Ppv.

[0083] That is, the battery system and photovoltaic power components together provide power for the charging station system.

[0084] Among them, Pcharging represents the charging demand power, Pbat represents the battery system power, and Ppv represents the photovoltaic module power.

[0085] Among them, battery power is given priority to provide charging response, which is defined as the first priority, and photovoltaic power is defined as supplementary power, which is defined as the second priority.

[0086] The charging demand is to establish quickly and output stably. At this time, the battery power is required to provide stable power support, and the battery power output + photovoltaic power output mode is preferred. Among them, photovoltaic power can only play a balancing role due to its intermittent, interrupted and unstable power characteristics, and effectively reduce the battery power output, reflecting the photovoltaic energy supplement effect and reducing the battery in a constant power output state. After charging is established, the charging power balance is maintained.

[0087] Execute the power dynamic balancing strategy: define photovoltaic power as the priority charging power, defined as the first priority, and define battery power as the supplementary charging power, defined as the second priority. Photovoltaic power is the main source of energy for the photovoltaic storage and charging system. When executing power balancing, photovoltaic power is used first;

[0088] Pcharging=Pbat↓+Ppv↑&Pcharging=Pbat↑+Ppv↓.

[0089] The above relationship is explained as follows: the photovoltaic power Ppv in the relationship is a variable due to the influence of unstable power generation. When the Ppv power increases, the power balance is maintained and the Pbat power decreases accordingly. Similarly, when the Ppv power decreases, the power balance is maintained and the Pbat power increases accordingly.

[0090] (2) Pcharge < Ppv:

[0091] Execute the charging system demand generation strategy:

[0092] Pcharge=Pbat+Ppv.

[0093] Execute the power dynamic balancing strategy:

[0094] Pcharging = -Pbat + Ppv↑&Pcharging = -Pbat + Ppv↓.

[0095] The above relationship is explained as follows: -Pbat represents that the battery is charging. The photovoltaic power Ppv in the relationship is a variable due to the influence of unstable power generation. When the Ppv power increases, the power balance is maintained, and the -Pbat power decreases accordingly. Similarly, when the Ppv power decreases, the power balance is maintained, and the -Pbat power increases accordingly. The battery power plays a stabilizing role.

[0096] In step S2, the photovoltaic power module and the battery system are preferentially used to provide power to the charging station system, specifically:

[0097] With photovoltaic power as the first priority and battery system as the second priority, power is provided to the charging station system;

[0098] When the power demand of the charging station system is greater than the sum of the power of the photovoltaic power components and the battery system, if the photovoltaic power meets the preset instability judgment condition, the power provided to the charging station system is reduced or stopped.

[0099] In this embodiment, when the battery SOC is less than 30%, the photovoltaic power is the first priority and the battery system is the second priority. The following judgment is made:

[0100] (1) Pcharge ≥ Ppv + Pbat:

[0101] Execute the stop charging station strategy and stop charging: PV power + battery power take priority response, with PV power as the first priority and battery power as the second priority. If the PV power is unstable, it is necessary to lower the charging power or stop charging.

[0102] (2) Pcharge < Ppv + Pbat:

[0103] Execute the charging system demand generation strategy: photovoltaic power + battery power priority response, with photovoltaic power as the first priority and battery power as the second priority;

[0104] Pcharging = Ppv↑+-Pbat↓&Pcharging = Ppv↓+±Pbat.

[0105] Photovoltaic power + battery power > charging power, with photovoltaic power taking priority and battery power playing a stabilizing role. When photovoltaic power fluctuates, ±Pbat represents the direction of charge and discharge, + for battery discharge, - for battery charging.

[0106] S3. The battery SOC is judged. If the battery SOC is greater than a preset second threshold, the battery system assists the photovoltaic power component to stably connect to the grid for power generation. Otherwise, the photovoltaic power component is discharged first, and the battery system does not participate in the regulation.

[0107] In step S3, the battery system assists the photovoltaic power assembly to stabilize the grid-connected power generation as follows:

[0108] The photovoltaic power components are given the first priority, and the battery system is given the second priority to provide power to the mains, wherein the battery system provides supplementary power for the photovoltaic power components.

[0109] In this embodiment, the second threshold is 80%, and in other equivalent embodiments, it can be adjusted according to actual conditions.

[0110] In this embodiment, when the battery SOC is greater than 80%, the battery assists the photovoltaic power generation to stabilize the grid.

[0111] The details are as follows:

[0112] (1) Pac>50%P hybrid (P hybrid is the rated power of the photovoltaic and energy storage hybrid inverter):

[0113] Execute the dynamic balancing strategy of grid-connected power generation: photovoltaic power is defined as the priority discharge power, defined as the first priority, and battery power is defined as the dynamic adjustment power, defined as the second priority;

[0114] Pac=Pbat / Pdc↓+Ppv↑

[0115] &

[0116] Pac=Pbat / Pdc↑+Ppv↓.

[0117] Among them, Pac represents the mains power, and Pdc represents the output side power.

[0118] (2) Pac<50%P mix:

[0119] Implement dynamic balancing strategy for grid-connected power generation;

[0120] Pac=-Pbat / Pdc+Ppv↑&Pcharge=±Pbat / Pdc+Ppv.

[0121] In step S3, the photovoltaic power components are discharged first, and the battery system does not participate in the regulation. Specifically:

[0122] The photovoltaic power components discharge first to provide power to the mains, and the battery system does not participate in the regulation;

[0123] When the mains power is less than a first preset ratio of the photovoltaic-storage hybrid inverter power, and the power of the photovoltaic power component is greater than a second preset ratio of the photovoltaic-storage hybrid inverter power, if the photovoltaic power meets the preset instability judgment conditions, the grid-connected power generation power provided to the mains is reduced, or the grid-connected power generation power provided to the mains is stopped.

[0124] In this embodiment, when the battery SOC is less than 80%, the photovoltaic power is defined as the priority discharge power, and the battery does not participate in the dynamic regulation.

[0125] The details are as follows:

[0126] (1) Ppv>30%P hybrid (P hybrid is the rated power of the photovoltaic storage hybrid inverter):

[0127] Execute the full power strategy of grid-connected power generation: PV power is defined as the priority discharge power and is defined as the first priority;

[0128] Pac=Ppv↑.

[0129] Implementation of grid-connected power reduction strategy: PV power is defined as the priority discharge power and is defined as the first priority;

[0130] Pac=Ppv↓.

[0131] Implement power reduction strategy for grid-connected power generation.

[0132] (2) Ppv ≤ 30% P hybrid (P hybrid is the rated power of the photovoltaic storage hybrid inverter) and the Ppv power fluctuation is 50%-100%:

[0133] Execute the grid-connected power stop strategy and switch to the battery charging strategy: PV power is defined as the priority discharge power. If the PV power is unstable, it is necessary to reduce the grid-connected discharge power or stop charging;

[0134] Ppv↑=-Pbat↑;

[0135] Ppv↓=-Pbat↓.

[0136] Currently, the Pac demand power is limited to within 30%, and the Ppv power fluctuation is between 50%-100%, which will not affect the power generation. The battery is always in a charging state and maintains a single state. What changes is the battery charging power.

[0137] In summary, the present invention provides a photovoltaic storage and charging fusion system and charging method, which are equipped with a photovoltaic storage and charging circuit, which can independently use photovoltaic power generation to charge the battery and the charging station system through a photovoltaic storage hybrid inverter. At the same time, the storage and charging circuit can also independently use the mains power to charge and discharge the battery and the charging station system; it can support the charging of the charging station system and the battery charging and discharging operation without using the mains power. When there is no car charging, the storage and charging circuit supplies power to the photovoltaic storage and charging circuit to assist the photovoltaic stable grid-connected discharge power operation function, which can effectively solve the problem of photovoltaic abandonment with a DC coupling architecture; at the same time, it can assist in solving the problem of the impact of the unstable power generation characteristics of the photovoltaic system on the mains, which is more friendly to the power grid and can play a certain supporting role; the charging circuit of the dual-channel PCS and the hybrid inverter connected to the charging station system is independent and is not affected by the battery voltage. The output voltage can be set higher to improve the charging efficiency of the charging station.

[0138] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A charging method combining light storage and charging, characterized in that: Based on a photovoltaic storage and charging fusion system, the implementation includes the following steps: S1. Determine whether there is a vehicle charging demand in the charging station system. If so, implement the operation strategy of charging the charging station system and charging and discharging the battery system without using the mains power, and enter step S2. Otherwise, implement the operation strategy of the storage and charging circuit supplying power to the photovoltaic storage and charging circuit when there is no vehicle charging, and assist the photovoltaic to stabilize the grid-connected discharge power, and enter step S3. S2. Determine the battery SOC. If the battery SOC is greater than a preset first threshold, the battery system will give priority to providing power to the charging station system. Otherwise, the photovoltaic power module and the battery system will give priority to providing power to the charging station system. In step S2, the battery system preferentially provides power to the charging station system as follows: The battery system is the first priority, and the photovoltaic power module is the second priority to provide power for the charging station system. The photovoltaic power module provides supplementary power for the battery system to establish a stable output charging demand, and then implement a power dynamic balance strategy; The power dynamic balancing strategy is specifically as follows: The photovoltaic power module is given the first priority, and the battery system is given the second priority to provide power to the charging station system, wherein the battery system provides supplementary power to the photovoltaic power module; In step S2, the battery system preferentially provides power to the charging station system as follows: The battery system is the first priority, and the photovoltaic power module is the second priority, providing power for the charging station system, wherein the photovoltaic power module provides supplementary power for the battery system, and then realizes the power dynamic balance strategy; The power dynamic balancing strategy is specifically as follows: The photovoltaic power module is given the first priority, and the battery system is given the second priority to provide power to the charging station system, wherein the battery system provides supplementary power to the photovoltaic power module; In step S2, the photovoltaic power module and the battery system are preferentially used to provide power to the charging station system, specifically: With photovoltaic power as the first priority and battery system as the second priority, power is provided to the charging station system; When the power demand of the charging station system is greater than the sum of the power of the photovoltaic power components and the battery system, if the photovoltaic power meets the preset unstable judgment condition, the power provided to the charging station system is reduced, or the power provided to the charging station system is stopped; S3, judging the battery SOC, if the battery SOC is greater than a preset second threshold, the battery system assists the photovoltaic power component to stably connect to the grid for power generation, otherwise the photovoltaic power component is discharged first, and the battery system does not participate in the regulation; In step S3, the photovoltaic power components are discharged first, and the battery system does not participate in the regulation. Specifically: The photovoltaic power components discharge first to provide power to the mains, and the battery system does not participate in the regulation; When the city power is less than the first preset ratio of the photovoltaic-storage hybrid inverter power, and the power of the photovoltaic power component is greater than the second preset ratio of the photovoltaic-storage hybrid inverter power, if the photovoltaic power meets the preset instability judgment condition, the grid-connected power generation provided to the city power is reduced, or the grid-connected power generation provided to the city power is stopped; When the power of the photovoltaic power module is less than the second preset ratio of the photovoltaic power storage hybrid inverter power, and the power fluctuation of the photovoltaic power module is between 50% and 100%, the grid-connected power generation power stop strategy is executed and the battery charging strategy is switched to, and the battery system power is positively correlated with the photovoltaic power; The photovoltaic storage and charging fusion system includes a photovoltaic storage hybrid inverter, a photovoltaic power module, a dual-channel PCS and a battery system; The input side DC in the dual-channel PCS is connected to the battery system, and the output side DC is connected to the charging station system, supporting the output of high voltage and wide range DC voltage, and AC access to the power grid; The charging station system consists of a DCDC and a charging pile; The PV side of the photovoltaic storage hybrid inverter is connected to the photovoltaic power component, the output DC is connected to the charging station system, and the AC is connected to the power grid; The photovoltaic-storage hybrid inverter adopts a high-voltage grid-connected inverter. The photovoltaic side of the photovoltaic-storage hybrid inverter has photovoltaic power components that support access to a high voltage and wide range. The output side DC of the photovoltaic-storage hybrid inverter supports outputting a high voltage direct current voltage. The photovoltaic storage hybrid inverter and the dual-channel PCS are both communicatively connected to the photovoltaic storage charging system, and the dual-channel PCS is communicatively connected to the battery system.

2. The method for charging by combining light storage and charging according to claim 1, characterized in that: The photovoltaic storage hybrid inverter and the dual-channel PCS are both connected to the photovoltaic storage charging system 485 for communication, and the dual-channel PCS is connected to the battery system for CAN communication.

3. The charging method of claim 1, characterized in that: In step S3, the battery system assists the photovoltaic power assembly to stabilize the grid-connected power generation as follows: The photovoltaic power components are given the first priority, and the battery system is given the second priority to provide power to the mains, wherein the battery system provides supplementary power for the photovoltaic power components.

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