A power stack system combining mppt and pcs

Abstract

The application discloses a power stacking system combined with MPPT and PCS, and relates to the technical field of solar power generation. The power stacking system comprises multiple groups of modular power units composed of MPPT units and PCS units, and the modular power units are vertically and horizontally connected in parallel and expanded to realize power stacking of multiple modular power units, wherein the MPPT units support one or more photovoltaic inputs, and convert unstable photovoltaic direct-current power into stable direct-current power output; and the PCS units are connected with corresponding MPPT units and energy storage batteries to receive direct-current power and convert the direct-current power into alternating-current power output. Through the modular stacking design, the basic units composed of the MPPT units and the PCS units are vertically stacked or horizontally expanded, so that the installation process is simplified.

Description

Technical Field

[0001] This application relates to the field of solar power generation technology, and in particular to a power stacking system combining MPPT and PCS. Background Technology

[0002] In existing photovoltaic energy storage systems, the MPPT (Maximum Power Point Tracking) controller and PCS (Power Conversion System) are typically deployed independently, leading to low system integration, complex installation processes, and difficulties in expansion. Different projects have significantly different requirements for photovoltaic input, battery capacity, and grid output, making it difficult for existing solutions to quickly adapt to these changes.

[0003] Therefore, there is an urgent need for a highly integrated and flexibly scalable joint solution of MPPT and PCS. Utility Model Content

[0004] To address the aforementioned issues, this application provides a solar control and inverter system based on MPPT and PCS power stacking. By pairing MPPT and PCS units, it supports three-layer vertical stacking and lateral expansion, thereby enabling flexible power configuration.

[0005] This application provides a power stacking system combining MPPT and PCS, including multiple sets of modular power units composed of paired MPPT and PCS units. The modular power units are vertically stacked in parallel and / or laterally extended in parallel to achieve power superposition of multiple modular power units, wherein:

[0006] The MPPT unit supports one or more photovoltaic inputs and converts unstable photovoltaic DC power into stable DC power output.

[0007] The PCS unit is connected to the corresponding MPPT unit and energy storage battery to receive DC power and convert it into AC power output.

[0008] In a further embodiment, the photovoltaic current value received by the MPPT unit is not greater than a first current threshold, and the photovoltaic voltage value received by the MPPT unit is not greater than a first voltage threshold; the input current value received by the PCS unit is not greater than a second current threshold, and the input voltage value received by the PCS unit is not greater than a second voltage threshold; the first current threshold is less than the second current threshold.

[0009] In a further embodiment, the power stacking system includes a power stacking cabinet that can accommodate multiple sets of modular power units.

[0010] In a further embodiment, the modular power units are stacked vertically in parallel, with heat dissipation ducts containing flow guides between the layers, and centrifugal fans are installed to achieve ventilation and heat dissipation.

[0011] In a further embodiment, the power stacking system also includes a temperature monitoring module, which is connected to the MPPT unit, the PCS unit and the centrifugal fan respectively.

[0012] The temperature monitoring module is used to acquire the operating temperature of the MPPT unit and PCS unit in real time, and adjust the fan speed of the centrifugal fan based on the acquired operating temperature to achieve dynamic heat dissipation.

[0013] In a further embodiment, the PCS unit operates in two modes: grid-connected mode and off-grid mode, with the switching between the two modes based on the working status of the power grid.

[0014] In a further embodiment, the MPPT unit and the PCS unit interact with each other for data and power control based on a communication protocol.

[0015] In a further embodiment, the communication protocol includes a CAN bus or an RS485 protocol. The MPPT unit sends power data to the PCS unit based on the communication protocol, and the PCS unit dynamically adjusts the charging and discharging strategy of the energy storage battery based on the received power data.

[0016] In a further embodiment, the MPPT unit and the PCS unit are connected via a pluggable standardized interface.

[0017] In a further embodiment, the power stacking system also includes a dynamic power distribution module, which is connected to the photovoltaic input terminal, the energy storage battery, and the load terminal respectively.

[0018] The dynamic power distribution module is used to acquire the photovoltaic input power at the photovoltaic input terminal, the charging and discharging status of the energy storage battery, and the power supply demand at the load terminal in real time to adjust the working status of the MPPT unit and PCS unit, thereby improving energy utilization efficiency.

[0019] Due to the adoption of the above technical solution, this application has at least one of the following beneficial effects compared with the prior art:

[0020] 1. Through modular stacking design, the basic unit composed of paired MPPT units and PCS units can be stacked vertically or expanded horizontally, simplifying the installation process.

[0021] 2. The system supports a wide range of DC voltage output and is compatible with various AC voltage specifications, improving its applicability.

[0022] 3. The total power of the system can be flexibly adjusted by simply increasing or decreasing the number of MPPT+PCS units to meet different scale requirements, depending on the photovoltaic input, battery capacity and grid output requirements.

[0023] 4. The system employs pre-reserved heat dissipation ducts between layers and a centrifugal fan installed at the top, while dynamically adjusting the fan speed using a temperature monitoring module, effectively improving heat dissipation efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] in:

[0026] Figure 1 A schematic diagram of the framework of an embodiment of the power stacking system provided in this application. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In existing technologies, traditional photovoltaic energy storage systems typically deploy the MPPT controller and PCS independently, resulting in low system integration, complex installation process, and difficulty in flexible expansion. At the same time, different projects have significantly different requirements for photovoltaic input, battery capacity, and grid output, and existing solutions cannot quickly adapt to these changes, thus limiting the system's flexibility and economy.

[0031] In view of this, this application proposes a modular power stacking scheme that pairs MPPT units with PCS units and supports vertical stacking and horizontal expansion. This not only simplifies the installation process and saves space, but also allows for flexible configuration of system scale according to actual needs. Furthermore, optimized heat dissipation design and communication protocols ensure efficient and stable operation of the system.

[0032] like Figure 1 As shown, Figure 1 The schematic diagram of an embodiment of the power stacking system provided in this application includes: multiple sets of modular power units composed of paired MPPT units and PCS units, wherein the modular power units are vertically stacked in parallel and / or horizontally extended in parallel to achieve power superposition of multiple modular power units.

[0033] The power stacking system of this embodiment includes three sets of modular power units composed of paired MPPT units and PCS units. Specifically, the first set of modular power units consists of paired PCS1 units and MPPT1 units; the second set consists of paired PCS2 units and MPPT2 units; and the third set consists of paired PCS3 units and MPPT3 units. It should be noted that in other embodiments, the power stacking system may include one, two, or more than three sets of modular power units, without any limitation.

[0034] The MPPT unit supports one or more photovoltaic inputs, converting unstable photovoltaic DC power into stable DC output. For example, PV1 (PV2 and PV3) contains one or more photovoltaic inputs. In one specific embodiment, a single MPPT unit (PV1, PV2, and PV3) can connect to eight photovoltaic panels. The MPPT unit monitors the voltage and current of each photovoltaic input in real time, and uses a built-in high-efficiency MPPT algorithm to find the optimal operating point, ensuring that it can output the most optimized and stable DC voltage even when the light conditions change.

[0035] The PCS unit is connected to the MPPT unit and the battery side to receive DC power and convert it into AC power output; that is, the PCS unit is connected to the MPPT unit to receive DC power from the MPPT unit; the PCS unit is connected to the energy storage battery to receive DC power from the energy storage battery; the PCS unit converts the DC power received from the MPPT unit and / or the DC power received from the energy storage battery into AC power output to the grid or load.

[0036] The MPPT unit converts multiple photovoltaic inputs into a stable DC voltage, which is then connected via cable to its paired PCS unit. The PCS unit supports battery input, processes the DC power from the MPPT unit, and converts it into AC output compatible with various voltage specifications, depending on grid demand or load requirements in off-grid mode.

[0037] In addition, the PCS unit can convert the received DC power into AC power output suitable for the power grid; its output voltage is compatible with multiple standards, such as 220 / 380V or 230 / 400V, and the voltage adjustment range can be flexibly adjusted between 0.85Un and 1.1Un, improving the applicability of the system.

[0038] It should be clarified that the PCS unit only uses the DC power sent by the MPPT unit when the DC power sent by the MPPT unit cannot meet the load demand, and only then will it use the DC power input from the battery. The PCS unit is not only responsible for power conversion, but also can dynamically adjust the battery charging and discharging strategy based on the real-time power data sent by the MPPT unit, thereby extending the battery life.

[0039] In summary, the power stacking system comprises multiple sets of modular power units, each consisting of paired MPPT and PCS units. These modular power units are vertically stacked in parallel and / or horizontally extended in parallel to achieve power superposition of multiple modular power units. Specifically, the MPPT unit supports one or more photovoltaic inputs, converting unstable photovoltaic DC power into stable DC output. The PCS unit is connected to its corresponding MPPT unit and energy storage battery to receive DC power and convert it into AC output. The modular stacking design simplifies the installation process by vertically stacking or horizontally expanding the basic units composed of paired MPPT and PCS units.

[0040] The photovoltaic current value received by the MPPT unit is not greater than the first current threshold, and the photovoltaic voltage value received by the MPPT unit is not greater than the first voltage threshold; the input current value received by the PCS unit is not greater than the second current threshold, and the input voltage value received by the PCS unit is not greater than the second voltage threshold.

[0041] In one embodiment, the MPPT unit is designed to receive a photovoltaic current value not exceeding a first current threshold of 40A and a photovoltaic voltage value not exceeding a first voltage threshold of 1000V; for the PCS unit, its design parameters are that the maximum input current value received does not exceed a second current threshold of 175A and the maximum input voltage value received does not exceed a second voltage threshold of 1000V.

[0042] The first current threshold is lower than the second current threshold. The photovoltaic panel outputs a relatively small current; setting a lower first current threshold ensures that the MPPT unit will not be damaged by excessive current when receiving photovoltaic current. The PCS unit is responsible for converting DC to AC; when the energy storage battery discharges, the PCS unit needs to handle a larger current than the photovoltaic source. The second current threshold is higher than the first current threshold to meet the current requirements of the PCS unit in different operating modes.

[0043] The PCS unit receives DC power from the MPPT unit and / or the battery side and converts it into AC power output suitable for grid use, ensuring that the PCS unit can operate efficiently and safely under both high and low load conditions.

[0044] By setting clear first current and first voltage thresholds, as well as second current and second voltage thresholds, the MPPT and PCS units are ensured to operate within their rated ranges, avoiding hardware damage or performance degradation due to overload, thereby improving the safety and long-term reliability of the entire system. Precise control of the input current and voltage thresholds helps optimize the execution efficiency of the MPPT algorithm, enabling the MPPT unit to more accurately track the maximum power point of the photovoltaic array and maintain optimal energy conversion efficiency even when environmental conditions change.

[0045] In one embodiment, the power stacking system includes a power stacking cabinet that can accommodate multiple sets of modular power units. In this embodiment, a single power stacking cabinet accommodates three sets of modular power units. The power stacking system combining MPPT and PCS adopts vertical stacking. Each power stacking cabinet can accommodate multiple sets of modular power units formed by pairing MPPT units and PCS units. These units are arranged in a vertical stacking arrangement, with dedicated heat dissipation ducts reserved between layers, and centrifugal fans installed at the top to achieve forced ventilation and heat dissipation.

[0046] To further optimize airflow distribution, baffles were installed inside the heat dissipation duct to ensure that air can pass evenly through each layer of equipment for effective cooling.

[0047] By using a dedicated heat dissipation duct in the vertical stacking structure and a centrifugal fan installed at the top, a forced ventilation heat dissipation mechanism is achieved, which effectively reduces the operating temperature of each component inside the system and improves the overall heat dissipation efficiency. This helps to extend the lifespan of electronic components and reduce the risk of failure due to overheating.

[0048] In this embodiment, the power stacking cabinet houses three sets of modular power units. If there are fewer than three sets of modular power units, the energy input from the photovoltaic system cannot be fully utilized, resulting in a lower-than-expected energy conversion efficiency for the overall system. Furthermore, it cannot provide sufficient output power when the load demand is high. If there are more than three sets of modular power units, the heat generation of a single power stacking cabinet increases, and even with ventilation and heat dissipation achieved through airflow ducts based on baffles and centrifugal fans, sufficient heat dissipation cannot be achieved. In addition, the space in the power stacking cabinet is limited, and too many modular power units will lead to a compact layout, which is not conducive to installation and maintenance.

[0049] The power stacking system also includes a temperature monitoring module (not shown in the figure), which is connected to the MPPT unit, the PCS unit and the centrifugal fan respectively. The temperature monitoring module is used to obtain the operating temperature of the MPPT unit and the PCS unit in real time, and adjust the fan speed of the centrifugal fan based on the obtained operating temperature to achieve dynamic heat dissipation.

[0050] Based on the acquired operating temperature data, the system can dynamically adjust the speed of the top centrifugal fan to maintain the optimal operating temperature range, prevent overheating, and ensure stable system operation. The introduction of the temperature monitoring module enables the system to automatically adjust the fan speed according to the actual operating temperature, providing sufficient cooling capacity when needed and reducing fan speed when conditions permit, thus saving energy consumption.

[0051] In another embodiment, the power stacking system combining MPPT and PCS adopts a laterally extended structure, which will not be described in detail here.

[0052] The PCS unit operates in both grid-connected and off-grid modes, switching between the two modes based on the grid's operating status, which includes normal operation and abnormal operation. When the grid is in normal operation, the PCS unit converts the DC power received from the MPPT unit into AC power and synchronously feeds it back into the grid; excess power can be sold to the grid company, achieving efficient energy utilization and maximizing economic benefits.

[0053] If the power grid is detected to be in an abnormal operating state, such as a power grid failure or no public power grid connection, the PCS unit will automatically switch to off-grid mode. In this mode, the PCS unit directly supplies power to the local load, ensuring that users can still obtain a stable power supply even without power grid support.

[0054] By seamlessly switching between grid-connected and off-grid modes, the system can not only provide efficient and stable power output when the grid is normal, but also quickly switch to independent power supply mode when the grid fails, ensuring uninterrupted operation of important equipment and improving the reliability and stability of the entire system.

[0055] The MPPT unit and the PCS unit interact in real time and coordinate power control based on a communication protocol. The communication protocol includes CAN bus or RS485 protocol. The MPPT unit sends real-time power data to the PCS unit based on the communication protocol. The real-time power data includes, but is not limited to, photovoltaic input voltage, current and maximum power point tracking status.

[0056] The PCS unit dynamically adjusts the battery charging and discharging strategy based on the received data. After receiving data from the MPPT unit, the PCS unit dynamically adjusts its operating mode and output strategy based on the current grid status, battery charging and discharging requirements, and load conditions. For example, during the day when there is sufficient sunlight, it prioritizes using energy from the photovoltaic panels to power the load and charge the battery; while at night or when there is insufficient sunlight, it draws power from the battery to supply the load, and can also feed excess power back to the grid if necessary.

[0057] Through real-time data interaction, the PCS unit can dynamically adjust the battery charging and discharging strategy based on the latest photovoltaic input information, ensuring that renewable energy can be maximized at any time, reducing dependence on traditional energy sources, and improving the overall system's energy efficiency ratio. The real-time monitoring and adjustment mechanism enables the system to respond quickly to changes in external conditions, such as fluctuations in light intensity caused by weather changes, thereby maintaining stable operation and avoiding equipment damage or other problems caused by unstable energy supply.

[0058] The MPPT unit and PCS unit are connected via a pluggable standardized interface, enabling modular, rapid replacement and maintenance. Both the MPPT unit and PCS unit are designed as independent modules with uniform physical dimensions and electrical interface standards. These modules are connected to other system components via pluggable standardized interfaces.

[0059] When a unit needs maintenance or malfunctions, technicians can simply unplug the faulty unit and insert a new or repaired one; no complicated disassembly or reconfiguration process is required, greatly reducing downtime and maintenance costs.

[0060] The power stacking system also includes a dynamic power distribution module (not shown in the figure), which is connected to the photovoltaic input terminal, the energy storage battery, and the load terminal. The dynamic power distribution module is used to acquire real-time photovoltaic input power, the charge / discharge state of the energy storage battery, and the power supply demand of the load terminal to adjust the operating state of the MPPT unit and PCS unit, thereby improving energy utilization efficiency. The specific steps by which the dynamic power distribution module adjusts the operating state of the MPPT unit and PCS unit based on the acquired data are described in detail below:

[0061] When the photovoltaic input power exceeds the power demand of the load, it checks whether the energy storage battery is in a rechargeable state. If the energy storage battery is in a rechargeable state, the excess energy is stored in the battery. If the energy storage battery is not in a rechargeable state, for example, if the current battery power is at the rated power, the MPPT unit is maintained and the output current of the MPPT unit is limited to prevent the battery from being overcharged.

[0062] When the photovoltaic input power is less than the power demand of the load, it is determined whether the energy storage battery is in a dischargeable state. If the energy storage battery is in a dischargeable state, the difference in power is supplemented from the battery to stabilize the power supply to the load and ensure the continuity of power supply.

[0063] It should be clarified that the dynamic power allocation module can purchase or sell electricity to the grid based on the grid's operating status, which will not be elaborated here.

[0064] By monitoring and adjusting the balance between photovoltaic input power, battery status, and load demand in real time, it ensures that available solar energy resources are fully utilized at any time, reducing waste and improving overall energy conversion efficiency; intelligently managing the battery charging and discharging process avoids overcharging or discharging, helping to protect the battery from damage, thereby extending its service life and reducing long-term operating costs.

[0065] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0066] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0067] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0068] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A power stacking system combining MPPT and PCS, characterized in that, This includes multiple sets of modular power units composed of paired MPPT and PCS units. These modular power units are vertically stacked in parallel and / or laterally extended in parallel to achieve power superposition of multiple modular power units, wherein: The MPPT unit supports one or more photovoltaic inputs, and converts unstable photovoltaic DC power into stable DC power output based on the MPPT unit; The PCS unit is connected to the corresponding MPPT unit and energy storage battery to receive DC power and convert it into AC power output.

2. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The photovoltaic current value received by the MPPT unit is not greater than a first current threshold, and the photovoltaic voltage value received by the MPPT unit is not greater than a first voltage threshold; the input current value received by the PCS unit is not greater than a second current threshold, and the input voltage value received by the PCS unit is not greater than a second voltage threshold; the first current threshold is less than the second current threshold.

3. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The power stacking system includes a power stacking cabinet that can accommodate multiple sets of the modular power units.

4. The power stacking system combining MPPT and PCS according to claim 3, characterized in that, The modular power units are stacked vertically in parallel, with heat dissipation ducts containing flow guides between the layers, and centrifugal fans are installed to achieve ventilation and heat dissipation.

5. The power stacking system combining MPPT and PCS according to claim 4, characterized in that, The power stacking system also includes a temperature monitoring module, which is connected to the MPPT unit, the PCS unit and the centrifugal fan respectively. The temperature monitoring module is used to acquire the operating temperature of the MPPT unit and the PCS unit in real time, and adjust the fan speed of the centrifugal fan based on the acquired operating temperature to achieve dynamic heat dissipation.

6. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The PCS unit has two operating modes: grid-connected mode and off-grid mode. The switching between the two modes is based on the working status of the power grid.

7. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The MPPT unit and the PCS unit interact with each other for data and power control based on a communication protocol.

8. The power stacking system combining MPPT and PCS according to claim 7, characterized in that, The communication protocol includes CAN bus or RS485 protocol. The MPPT unit sends power data to the PCS unit based on the communication protocol. The PCS unit dynamically adjusts the charging and discharging strategy of the energy storage battery based on the received power data.

9. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The MPPT unit and the PCS unit are connected via a pluggable standardized interface.

10. The power stacking system combining MPPT and PCS according to claim 1, characterized in that, The power stacking system also includes a dynamic power distribution module, which is connected to the photovoltaic input terminal, the energy storage battery and the load terminal respectively. The dynamic power allocation module is used to acquire the photovoltaic input power at the photovoltaic input terminal, the charging and discharging status of the energy storage battery, and the power supply demand at the load terminal in real time to adjust the working status of the MPPT unit and the PCS unit, thereby improving energy utilization efficiency.

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