Marine photovoltaic energy storage inverter

Abstract

The utility model provides a marine photovoltaic energy storage inverter, which relates to the technical field of marine equipment and comprises a photovoltaic cell panel DC1, a storage battery DC2, a direct current filtering module, a boosting module, an inversion module, an alternating current filtering module and a control module. The photovoltaic cell panel DC1 and the storage battery DC2 serve as direct current input and are connected with the direct current filtering module, the direct current filtering module is connected with the boosting module, the boosting module is connected with the inversion module, the inversion module is connected with the alternating current filtering module, and the alternating current filtering module is connected with the control module. According to the utility model, the design of double direct current filtering units is adopted, the interference of the input ends of the photovoltaic cell panel DC1 and the storage battery DC2 is effectively filtered, and the purity and stability of the marine direct current are ensured.

Description

Technical Field

[0001] This utility model relates to the field of marine equipment technology, and in particular to a marine photovoltaic energy storage inverter. Background Technology

[0002] With increasing global awareness of environmental protection and profound transformation of the energy structure, the application of photovoltaic energy storage technology in the shipbuilding sector has become an important direction for promoting the green and low-carbon development of the shipbuilding industry. The core of this technology lies in using photovoltaic modules to efficiently convert solar energy into electrical energy, and optimizing energy management through advanced energy storage systems, thereby achieving energy conservation, emission reduction, and environmental benefits during ship operation.

[0003] Currently, a series of technical challenges remain to be addressed when applying photovoltaic (PV) energy storage technology to ships. First, PV output power is unstable, with its curve often differing significantly from the ship's load curve. Both are affected by unpredictable factors such as weather and environment, requiring marine PV energy storage inverters to possess highly flexible adjustment capabilities and rapid response mechanisms to ensure the stable operation of the ship's power system. Second, the complexity of ship power systems places higher demands on the design of marine PV energy storage inverters. In hybrid electric power systems, the energy sources are diverse, including generators, PV power generation systems, and power storage batteries. Inverters need to accurately identify and adapt to switching between different power schemes, achieving effective power management and load distribution. Furthermore, considering the limited space and complex operating environment of ships, marine PV energy storage inverters must also be small in size, lightweight, and highly resistant to shock and vibration to meet the stringent requirements of actual ship operation.

[0004] Therefore, a marine photovoltaic energy storage inverter is proposed. Utility Model Content

[0005] This specification provides a marine photovoltaic energy storage inverter, which adopts a dual DC filter unit design to effectively filter out interference from the DC1 input terminals of the photovoltaic panel and the DC2 input terminal of the battery, ensuring the purity and stability of the marine DC power.

[0006] This specification provides a marine photovoltaic energy storage inverter, including: a photovoltaic panel DC1, a battery DC2, a DC filter module, a boost module, an inverter module, an AC filter module, and a control module;

[0007] The photovoltaic panel DC1 and the battery DC2 are connected to the DC filter module as DC inputs. The DC filter module is connected to the boost module, the boost module is connected to the inverter module, the inverter module is connected to the AC filter module, and the AC filter module is connected to the control module.

[0008] Optionally, the DC filtering module includes: a first DC filtering unit and a second DC filtering unit;

[0009] The photovoltaic panel DC1 is connected to the first DC filter unit, which includes a common-mode inductor L1 and a capacitor C1 connected in parallel; the battery DC2 is connected to the second DC filter unit, which includes a common-mode inductor L2 and a capacitor C2 connected in parallel; both the first DC filter unit and the second DC filter unit are connected to the boost module.

[0010] Optionally, the boost module includes: a maximum power point tracking control solar controller MPPT1 and a maximum power point tracking control solar controller MPPT2;

[0011] The common mode inductor L1 is connected to the maximum power point tracking control solar controller MPPT1, the common mode inductor L2 is connected to the maximum power point tracking control solar controller MPPT2, the maximum power point tracking control solar controller MPPT1 is connected to capacitor C3 and the maximum power point tracking control solar controller MPPT2 respectively, and the capacitor C1 is connected to the inverter module.

[0012] Optionally, the inverter module includes an insulated gate transistor (IGBT1);

[0013] The capacitor C1 is connected to the insulated gate transistor IGBT1. The switching frequency and duty cycle of the insulated gate transistor IGBT1 are adjusted by the control module, thereby controlling the output voltage and current waveform of the control module, and the control module is connected to the AC filter module.

[0014] Optionally, the AC filtering module includes: relay KJ1, a third AC filtering unit, varistor R1, and varistor R2;

[0015] The insulated gate transistor IGBT1 is connected to the relay KJ1, and the relay KJ1 is connected to the third AC filter unit. The third AC filter unit includes a common mode inductor L3 and a capacitor C4 connected in parallel. The third AC filter unit is connected to the varistor R1 and the varistor R2 respectively.

[0016] Optionally, the control module includes: a control unit and an auxiliary power supply VBAT1; the control unit includes a main digital signal processor DSP1 and a secondary digital signal processor DSP2 connected to each other;

[0017] The auxiliary power supply VBAT1 is connected to the insulated gate transistor IGBT1, the control unit, and the relay KJ1, respectively.

[0018] Optionally, it may also include: a transmission module connected to the control unit; the transmission module includes an RS485 communication device and an LCD display screen.

[0019] Optionally, it may also include: the relay KJ1 includes at least one of grid-connected relay, off-grid relay, and bypass relay.

[0020] This specification employs a dual DC filter unit design to effectively filter out interference at the DC1 input terminals of the photovoltaic panel and the DC2 input terminal of the battery, ensuring the purity and stability of the DC power. Equipped with two maximum power point tracking solar controllers (MPPT1 and MPPT2), the inverter can optimize the power output of the photovoltaic panel (DC1) and the battery (DC2) separately, achieving efficient utilization. The inverter module uses insulated gate transistors (IGBT1), and its switching frequency and duty cycle are adjusted by a precision control module to accurately control the output voltage and current waveforms, ensuring the quality of the AC output. Furthermore, the AC filter module includes a relay KJ1 (selectable as at least one of grid-connected, off-grid, or bypass relays) and filtering components to cope with the complex marine operating environment and ensure the stable operation of the power system. The control module is equipped with main and secondary digital signal processors (DSP1 and DSP2) and a transmission module, supporting RS485 communication and an LCD display for convenient remote monitoring and local operation. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the structure of a marine photovoltaic energy storage inverter provided in the embodiments of this specification;

[0023] Figure 2 A schematic diagram of a marine photovoltaic energy storage inverter provided as an embodiment of this specification;

[0024] Figure 3 This is a schematic diagram of the control principle of the energy storage boost and inversion section of a marine photovoltaic energy storage inverter, provided as an embodiment of this specification.

[0025] The attached diagram shows: 100, DC filter module; 200, boost module; 300, inverter module; 400, AC filter module; 500, control module. Detailed Implementation

[0026] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0027] The following is in conjunction with the appendix Figure 1-3 Exemplary embodiments of the present invention will be described more fully. However, exemplary embodiments can be implemented in many forms and should not be construed as limiting the present invention to the embodiments set forth herein. Rather, these exemplary embodiments are provided to make the present invention more comprehensive and complete, and to facilitate the full communication of the inventive concept to those skilled in the art. The same reference numerals in the figures denote the same or similar elements, components, or parts, and therefore repeated descriptions of them are omitted.

[0028] Subject to the technical concept of this utility model, the features, structures, characteristics or other details described in a particular embodiment may be combined in one or more other embodiments in a suitable manner.

[0029] In the description of specific embodiments, the features, structures, characteristics, or other details described herein are intended to enable those skilled in the art to fully understand the embodiments. However, it is not excluded that those skilled in the art can practice the technical solutions of this utility model without one or more of the specific features, structures, characteristics, or other details.

[0030] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0031] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0032] The terms “and / or” or “and / or” include all combinations of any one or more of the listed items.

[0033] Figure 1 A schematic diagram of a marine photovoltaic energy storage inverter provided as an embodiment of this specification includes:

[0034] Photovoltaic panel DC1, storage battery DC2, DC filter module 100, boost module 200, inverter module 300, AC filter module 400, control module 500;

[0035] The photovoltaic panel DC1 and the battery DC2 are connected to the DC filter module as DC inputs. The DC filter module is connected to the boost module, the boost module is connected to the inverter module, the inverter module is connected to the AC filter module, and the AC filter module is connected to the control module.

[0036] In the specific implementation of this specification, photovoltaic panel DC1 is the starting point of energy conversion, converting solar energy into direct current (DC) power. Battery DC2 serves as an energy storage device, providing DC power to the system during periods of insufficient sunlight or at night. Photovoltaic panel DC1 and battery DC2 are used as DC input sources. A DC filter module filters the DC power from photovoltaic panel DC1 and battery DC2, removing ripple and noise to ensure power quality, and outputs the filtered DC power to the boost module. The boost module boosts the filtered DC power to a voltage range suitable for the inverter module's operation and then transmits the boosted DC power to the inverter module. The inverter module converts the boosted DC power into alternating current (AC) power for use in household or industrial equipment, and then transmits the converted AC power to the AC filter module. The AC filter module filters the AC power output from the inverter module, removing harmonics and noise to improve power quality, and then outputs the filtered AC power to the load or the power grid. The control module monitors and controls the entire marine photovoltaic energy storage inverter system, including monitoring parameters such as voltage, current, and power factor, and adjusting the system's operating status based on factors such as light intensity and load demand.

[0037] The efficient conversion from solar energy to AC power is achieved through the combined use of boost and inverter modules. The use of DC and AC filter modules improves the purity of the electrical energy and the stability of the system. The DC2 battery, acting as an energy storage device, can provide power when sunlight is insufficient, enhancing the system's flexibility and adaptability. The control module can monitor and control the system status in real time, ensuring stable operation under various conditions. By fully utilizing solar energy resources, dependence on traditional energy sources is reduced, aligning with the trend of green and low-carbon development.

[0038] Optionally, the DC filtering module includes: a first DC filtering unit and a second DC filtering unit;

[0039] The photovoltaic panel DC1 is connected to the first DC filter unit, which includes a common-mode inductor L1 and a capacitor C1 connected in parallel; the battery DC2 is connected to the second DC filter unit, which includes a common-mode inductor L2 and a capacitor C2 connected in parallel; both the first DC filter unit and the second DC filter unit are connected to the boost module.

[0040] In the specific implementation of this specification, such as Figure 2 As shown, the first DC filter unit consists of a common-mode inductor L1 and a capacitor C1 connected in parallel. The common-mode inductor L1 is mainly used to suppress common-mode noise in the power supply line, that is, interference signals between the two lines and ground. The capacitor C1 is used to filter out high-frequency noise and ripple in the DC power, ensuring that the output DC power is smoother and more stable.

[0041] Similar to the first DC filter unit, the second DC filter unit consists of a common-mode inductor L2 and a capacitor C2 connected in parallel. The common-mode inductor L2 and capacitor C2 serve the same function as L1 and C1 in the first unit, but they are designed to handle the DC power output from the battery DC2.

[0042] Two independent DC filtering units filter the DC outputs of the photovoltaic panel (DC1) and the battery (DC2) respectively, effectively removing interference and noise and improving the system's power quality. This refined filtering helps reduce harmonics and noise in the system, thereby enhancing the stability and reliability of the entire marine photovoltaic energy storage inverter system. Dividing the DC filtering module into two units not only facilitates system maintenance and upgrades but also improves system flexibility and scalability. This modular design allows the system to be customized and optimized according to actual needs. High-quality DC power input to the boost and inverter modules helps reduce energy loss and improve the overall system conversion efficiency.

[0043] Optionally, the boost module includes: a maximum power point tracking control solar controller MPPT1 and a maximum power point tracking control solar controller MPPT2;

[0044] The common mode inductor L1 is connected to the maximum power point tracking control solar controller MPPT1, the common mode inductor L2 is connected to the maximum power point tracking control solar controller MPPT2, the maximum power point tracking control solar controller MPPT1 is connected to capacitor C3 and the maximum power point tracking control solar controller MPPT2 respectively, and the capacitor C1 is connected to the inverter module.

[0045] In the specific implementation described in this specification, the maximum power point tracking control solar controller MPPT1 calculates the current maximum power point (MPP) by monitoring the output voltage and current of the photovoltaic panel DC1 in real time, and adjusts its internal circuitry to ensure that the photovoltaic panel DC1 always operates near its maximum power point. Thus, even if lighting conditions change, the maximum power point tracking control solar controller MPPT1 can ensure that the photovoltaic panel DC1 outputs as much electrical energy as possible.

[0046] The maximum power point tracking (MPPT) solar controller 1 is also connected to capacitor C3, which may be used to smooth the power output of MPPT1 and reduce ripple. Simultaneously, MPPT1 is also connected to MPPT2, typically to enable information sharing or coordinated control between the two MPPT controllers.

[0047] Similar to the Maximum Power Point Tracking (MPPT1) solar controller, the MPPT2 solar controller also monitors the output voltage and current of the DC2 battery, calculates and adjusts its operating point to maximize the power output of the DC2 battery. This is especially important when powered by the DC2 battery in low light conditions or at night.

[0048] The boost module optimizes the power output of the photovoltaic panel DC1 and the battery DC2 through the maximum power point tracking control solar controllers MPPT1 and MPPT2, respectively, and boosts this power to a voltage range suitable for the inverter module to operate. This not only improves the system's energy conversion efficiency, but also enhances the system's flexibility and adaptability.

[0049] Optionally, the inverter module includes an insulated gate transistor (IGBT1);

[0050] The capacitor C1 is connected to the insulated gate transistor IGBT1. The switching frequency and duty cycle of the insulated gate transistor IGBT1 are adjusted by the control module, thereby controlling the output voltage and current waveform of the control module, and the control module is connected to the AC filter module.

[0051] In the specific embodiments described in this specification, the insulated-gate transistor IGBT1 is the core switching element in the inverter module. Its input terminal (gate) is connected to the control module, and its output terminal (collector and emitter) is connected to the DC power supply (DC power after filtering and boosting) and the AC filter module. The insulated-gate transistor IGBT1 converts DC power into AC power through rapid switching. Its switching frequency and duty cycle determine the voltage and current waveforms of the output AC power.

[0052] The control module controls the switching action of the IGBT1 by adjusting the gate voltage of the insulated gate transistor. Specifically, the control module generates a PWM (Pulse Width Modulation) signal, the frequency and duty cycle of which determine the switching frequency and duty cycle of the IGBT1.

[0053] Optionally, the AC filtering module includes: relay KJ1, a third AC filtering unit, varistor R1, and varistor R2;

[0054] The insulated gate transistor IGBT1 is connected to the relay KJ1, and the relay KJ1 is connected to the third AC filter unit. The third AC filter unit includes a common mode inductor L3 and a capacitor C4 connected in parallel. The third AC filter unit is connected to the varistor R1 and the varistor R2 respectively.

[0055] In the specific implementation of this specification, relay KJ1 is used to disconnect the circuit when the system starts up, shuts down, or encounters a fault, so as to protect the subsequent circuit from damage. It can also be used to switch different circuit paths or loads.

[0056] The common-mode inductor L3 and capacitor C3 are connected in parallel to form a filter network, which is used to filter out high-frequency noise and interference in AC signals and improve power quality.

[0057] A varistor is a non-linear element whose resistance decreases as the voltage increases. In circuits, they are commonly used for overvoltage protection. When the system voltage exceeds the varistor's threshold voltage, it quickly conducts, thus limiting further voltage increases and protecting downstream circuits and equipment from damage.

[0058] Optionally, the control module includes: a control unit and an auxiliary power supply VBAT1; the control unit includes a main digital signal processor DSP1 and a secondary digital signal processor DSP2 connected to each other;

[0059] The auxiliary power supply VBAT1 is connected to the insulated gate transistor IGBT1, the control unit, and the relay KJ1, respectively.

[0060] In the specific implementation described in this specification, the control unit consists of a main digital signal processor (DSP1) and a secondary digital signal processor (DSP2) interconnected. DSP1 and DSP2 are connected via an internal communication bus or interface to achieve data exchange and collaborative operation. DSP1, as the core controller of the system, is responsible for handling complex algorithms and control logic, such as PWM (Pulse Width Modulation) signal generation, system status monitoring, and fault diagnosis. DSP2 handles auxiliary tasks, such as real-time data acquisition, preprocessing, or simple control logic, to reduce the burden on the main DSP or provide additional functions.

[0061] Optionally, it may also include: a transmission module connected to the control unit; the transmission module includes an RS485 communication device and an LCD display screen.

[0062] In the specific embodiments described in this specification, RS485 is a differential transmission serial communication protocol with advantages such as long transmission distance and strong anti-interference capability. In the transmission module, RS485 communication devices are used to achieve remote communication with other devices (such as host computers, other control systems, etc.). RS485 communication devices are typically connected to external devices through a standard RS485 interface, using differential signals for data transmission. In power electronic systems, RS485 communication devices can be used for remote monitoring, data acquisition, fault diagnosis, and other functions in monitoring systems.

[0063] An LCD screen is used to display system status information, parameter settings, alarm information, etc. It provides users with an intuitive interface, allowing them to easily understand the system's operating status and perform corresponding operations. LCD screens are typically connected to the control unit via parallel interfaces, serial interfaces (such as SPI, I2C, etc.), or dedicated display interfaces. The type and specifications of the LCD screen can be selected according to system requirements, such as character displays, graphic displays, etc.

[0064] Optionally, it may also include: the relay KJ1 includes at least one of grid-connected relay, off-grid relay, and bypass relay.

[0065] In the specific embodiments described in this specification, grid-connected relays are typically used to control the connection between a power system and the power grid. When the system needs to supply power to the grid or obtain electrical energy from the grid, the grid-connected relay is activated or deactivated to achieve grid-connected or off-grid operation. In renewable energy systems such as solar power generation systems, wind power generation systems, and energy storage systems, grid-connected relays are indispensable components. They allow the system to automatically connect to the grid when certain conditions are met, in order to supply power to the grid or obtain electrical energy from the grid.

[0066] Off-grid relays, unlike grid-connected relays, are used to protect the system when it is disconnected from the power grid. When a grid fault occurs or the system needs to operate independently, the off-grid relay is activated to ensure electrical isolation between the system and the grid. Off-grid relays play a crucial role in scenarios such as islanded operation, emergency power systems, and power supply in remote areas. They allow the system to continue operating when the grid is unavailable, providing stable power to critical loads.

[0067] Bypass relays are typically used to bypass a device or component during maintenance or failure. When a part of the system needs repair or replacement, a bypass relay can be activated to divert current from that part to a backup path, ensuring the rest of the system can continue operating. Bypass relays are common components in systems requiring high reliability and availability, such as UPS (Uninterruptible Power Supply) systems, data center power systems, and industrial control systems. They allow the system to automatically switch to a backup path in the event of a failure, reducing downtime and data loss.

[0068] like Figure 3 As shown, Vpv is the input voltage of photovoltaic panel DC1, Ipv is the input current of photovoltaic panel DC1, Vdcref is determined based on the input voltage and input current, Vderef is the maximum power point tracking (MPPT) setpoint of photovoltaic panel DC1, Vdcsample is the sampled input voltage value of photovoltaic panel DC1, Vsample is the sampled voltage value after boosting, Vref is the boosted voltage setpoint, IL is the sampled current value of the boost inductor, and DW1 is the control duty cycle of QW1. The MPPT control strategy works as follows: the voltage (Vpv) and current (Ipv) are calculated by comparing the input power to obtain the (MPPT) Vdcref setpoint, and the error between Vdcref and Vdcsample is calculated by a PI loop. The error between Vref and the sampled voltage value (Vsample) after boosting is calculated and then processed by a PI loop. This error is added to the error calculated between Vdcref and Vdcsample by the PI loop to obtain the inductor current loop setpoint (Idcref). The error between the inductor current loop setpoint (Idcref) and the sampled inductor current value (IL) is calculated and then processed by a P loop to finally calculate the DW1 modulation ratio. DW1 is compared with a triangular carrier wave to generate a modulated square wave (QW1). The QW1 modulated signal drives the ICBT to achieve output voltage regulation and MPPT tracking function.

[0069] This specification employs a dual DC filter unit design to effectively filter out interference at the DC1 input terminals of the photovoltaic panel and the DC2 input terminal of the battery, ensuring the purity and stability of the DC power. Equipped with two maximum power point tracking solar controllers (MPPT1 and MPPT2), the inverter can optimize the power output of the photovoltaic panel (DC1) and the battery (DC2) separately, achieving efficient utilization. The inverter module uses insulated gate transistors (IGBT1), and its switching frequency and duty cycle are adjusted by a precision control module to accurately control the output voltage and current waveforms, ensuring the quality of the AC output. Furthermore, the AC filter module includes a relay KJ1 (selectable as at least one of grid-connected, off-grid, or bypass relays) and filtering components to cope with the complex marine operating environment and ensure the stable operation of the power system. The control module is equipped with main and secondary digital signal processors (DSP1 and DSP2) and a transmission module, supporting RS485 communication and an LCD display for convenient remote monitoring and local operation.

[0070] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that this utility model is not inherently related to any specific computer, virtual device, or electronic device, and various general-purpose devices can also implement this utility model. The above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0071] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0072] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A marine photovoltaic energy storage inverter, characterized in that, include: Photovoltaic panel DC1, battery DC2, DC filter module, boost module, inverter module, AC filter module, control module; The photovoltaic panel DC1 and the battery DC2 are connected to the DC filter module as DC inputs. The DC filter module is connected to the boost module, the boost module is connected to the inverter module, the inverter module is connected to the AC filter module, and the AC filter module is connected to the control module.

2. The marine photovoltaic energy storage inverter as described in claim 1, characterized in that, The DC filtering module includes: a first DC filtering unit and a second DC filtering unit; The photovoltaic panel DC1 is connected to the first DC filter unit, which includes a common-mode inductor L1 and a capacitor C1 connected in parallel; the battery DC2 is connected to the second DC filter unit, which includes a common-mode inductor L2 and a capacitor C2 connected in parallel; both the first DC filter unit and the second DC filter unit are connected to the boost module.

3. The marine photovoltaic energy storage inverter as described in claim 2, characterized in that, The boost module includes: a maximum power point tracking control solar controller MPPT1 and a maximum power point tracking control solar controller MPPT2; The common mode inductor L1 is connected to the maximum power point tracking control solar controller MPPT1, the common mode inductor L2 is connected to the maximum power point tracking control solar controller MPPT2, the maximum power point tracking control solar controller MPPT1 is connected to capacitor C3 and the maximum power point tracking control solar controller MPPT2 respectively, and the capacitor C1 is connected to the inverter module.

4. The marine photovoltaic energy storage inverter as described in claim 3, characterized in that, The inverter module includes an insulated gate transistor IGBT1; The capacitor C1 is connected to the insulated gate transistor IGBT1. The switching frequency and duty cycle of the insulated gate transistor IGBT1 are adjusted by the control module, thereby controlling the output voltage and current waveform of the control module, and the control module is connected to the AC filter module.

5. The marine photovoltaic energy storage inverter as described in claim 4, characterized in that, The AC filtering module includes: relay KJ1, third AC filtering unit, varistor R1, and varistor R2; The insulated gate transistor IGBT1 is connected to the relay KJ1, and the relay KJ1 is connected to the third AC filter unit. The third AC filter unit includes a common mode inductor L3 and a capacitor C4 connected in parallel. The third AC filter unit is connected to the varistor R1 and the varistor R2 respectively.

6. The marine photovoltaic energy storage inverter as described in claim 5, characterized in that, The control module includes: a control unit and an auxiliary power supply VBAT1; the control unit includes a main digital signal processor DSP1 and a secondary digital signal processor DSP2 connected to each other. The auxiliary power supply VBAT1 is connected to the insulated gate transistor IGBT1, the control unit, and the relay KJ1, respectively.

7. The marine photovoltaic energy storage inverter as described in claim 6, characterized in that, Also includes: A transmission module connected to the control unit; the transmission module includes an RS485 communication device and an LCD display screen.

8. The marine photovoltaic energy storage inverter as described in claim 7, characterized in that, The relay KJ1 includes at least one of the following: grid-connected relay, off-grid relay, and bypass relay.

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