Independent photovoltaic grid-connected power generation system established by simulating state grid through sine wave inverter

Abstract

The utility model provides an independent photovoltaic grid-connected power generation system established by simulating a state grid through a sine wave inverter, which comprises a photovoltaic panel, an MPPT (maximum power point tracking) inverter, an energy storage battery charger, a distribution box, a low-voltage direct-current inverter, an energy storage battery and a current transformer, the output end of the photovoltaic panel is connected with the input end of the MPPT inverter, and the output end of the photovoltaic panel is connected with the input end of the energy storage battery. The output end of the energy storage battery is connected with the input end of the low-voltage direct-current inverter, and the output end of the low-voltage direct-current inverter is connected with the input end of the distribution box; the photovoltaic panel can convert solar energy into electric energy, the electric energy is inverted into 220V alternating current through the MPPT inverter to be used by a user, a small part of electricity flows into the energy storage battery through the energy storage battery charger, the energy storage battery supplies power to the user through the low-voltage direct-current inverter at night, and through the cooperation of the current transformer and the MPPT inverter, the energy storage battery supplies power to the user through the low-voltage direct-current inverter. And the reverse current is prevented from generating voltage impact on the low-voltage direct-current inverter.

Description

Technical Field

[0001] The utility model belongs to the technical field of photovoltaic grid-connected power generation, and more specifically, relates to a sine wave inverter simulating a national power grid to form an independent photovoltaic grid-connected power generation system. Background Art

[0002] With the increasingly severe energy crisis and environmental problems in recent years, the development of renewable energy power generation technology has received widespread attention. Photovoltaic power generation, as a clean and renewable energy utilization method, has been rapidly promoted and applied worldwide due to its advantages such as no pollution, no noise, and no need for fuel.

[0003] For example, the Chinese utility model patent No. 200910135384.7 provides a three-phase four-bridge-arm inverter and a photovoltaic grid-connected power generation system for photovoltaic grid-connected power generation. Its input end is connected to the photovoltaic array, and the output end is connected to the three-phase power grid. The connection point of the two switching tubes connected in series is the output end of each bridge arm. The neutral bridge arm includes two switching tubes connected in series. The connection point of the two switching tubes constitutes the output end of the neutral bridge arm, and the output end of the neutral bridge arm is connected to the neutral line of the three-phase power grid. The power generation system has strong adaptability to grid imbalance and the harmonic content of the grid-connected current is extremely small. Currently, traditional independent photovoltaic grid-connected power generation systems often cannot generate electricity continuously when there is no sunlight at night and need to be supplied to users by the national power grid. Utility Model Content

[0004] In order to solve the above technical problems, the present invention provides a sine wave inverter to simulate the national grid to form an independent photovoltaic grid-connected power generation system, so as to solve the technical problem in the existing technology that the traditional independent photovoltaic grid-connected power generation system often cannot generate electricity continuously when there is no sunlight at night and needs to be supplied to users by the national grid.

[0005] The purpose and function of the sine wave inverter of this utility model to simulate the national grid to establish an independent photovoltaic grid-connected power generation system are achieved by the following specific technical means:

[0006] The sine wave inverter simulates the State Grid to build an independent photovoltaic grid-connected power generation system, including photovoltaic panels, MPPT inverters, energy storage battery chargers, distribution boxes, low-voltage DC inverters, energy storage batteries, and current transformers;

[0007] The output end of the photovoltaic panel is connected to the input end of the MPPT inverter, the output end of the MPPT inverter is connected to the input end of the distribution box, the output end of the photovoltaic panel is connected to the input end of the energy storage battery charger, the output end of the energy storage battery charger is connected to the input end of the energy storage battery, the output end of the energy storage battery is connected to the input end of the low-voltage DC inverter, the output end of the low-voltage DC inverter is connected to the input end of the distribution box, and the current transformer is connected in series to the output live wire L of the low-voltage DC inverter.

[0008] According to a preferred embodiment, the output end of the energy storage battery charger is connected to the energy storage battery and the input end of the low-voltage DC inverter respectively.

[0009] According to a preferred embodiment, there are multiple photovoltaic panels and multiple MPPT inverters, and each photovoltaic panel corresponds to one MPPT inverter.

[0010] According to a preferred embodiment, the output end of the distribution box is connected to the national power grid.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. Through the setting of photovoltaic panels, during the day, the photovoltaic panels generate electricity, most of which is inverted into 220V AC power by the MPPT inverter for users to use, and a small part of the electricity flows into the energy storage battery through the energy storage battery charger. Through the setting of the distribution box, when the power generation power of the photovoltaic panels is greater than the power consumption of the user, the excess electricity is stored in the energy storage battery until the energy storage battery is fully charged. When the power generation power of the photovoltaic panels is less than the power consumption of the user, the energy storage battery transmits electricity to the outside through the low-voltage DC inverter, and transmits electricity to the distribution box together with the MPPT inverter for users to use; at night, the electricity required by users is provided by the energy storage battery through the low-voltage DC inverter, which effectively solves the problem that traditional independent photovoltaic grid-connected power generation systems often cannot generate electricity continuously when there is no sunlight at night and need to be supplied to users by the national grid.

[0013] 2. Through the setting of the current transformer, the electric energy current passing through the live wire of the low-voltage DC inverter can be detected. The current transformer is connected in series to the output live wire L of the low-voltage DC inverter. Through the cooperation of the current transformer and the MPPT inverter, the reverse current can be effectively prevented from causing voltage shock to the low-voltage DC inverter. The distribution box can be connected to the national grid and use the national grid as a hot backup. When the independent photovoltaic grid-connected power generation system fails, the distribution box switches to the national grid for power supply, ensuring normal power supply to users and improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1This is a principle block diagram of the utility model's sine wave inverter simulating the national power grid to establish an independent photovoltaic grid-connected power generation system.

[0015] In the figure, the corresponding relationship between the component names and the drawing numbers is as follows:

[0016] 10. Photovoltaic panels; 11. MPPT inverter; 12. Distribution box; 13. Energy storage battery charger; 14. Energy storage battery; 15. Low-voltage DC inverter; 16. Current transformer. DETAILED DESCRIPTION

[0017] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Example

[0018] As attached Figure 1 As shown:

[0019] The utility model provides a sine wave inverter simulating the national power grid to form an independent photovoltaic grid-connected power generation system. The independent photovoltaic grid-connected power generation system includes a photovoltaic panel 10, an MPPT inverter 11, an energy storage battery charger 13, a distribution box 12, a low-voltage DC inverter 15, an energy storage battery 14, and a current transformer 16. The photovoltaic panel 10 can convert solar energy into electrical energy for power generation during the day, and the power generation of the photovoltaic panel 10 is a clean and renewable energy utilization method, which effectively improves economic benefits. The output end of the photovoltaic panel 10 is connected to the input end of the MPPT inverter 11, and the output end of the MPPT inverter 11 is connected to the input end of the distribution box 12. The MPPT inverter 1 The DC power generated by the photovoltaic panel 10 can be inverted into AC power and then output to the distribution box 12. The output end of the photovoltaic panel 10 is connected to the input end of the energy storage battery charger 13. The output end of the energy storage battery charger 13 is respectively connected to the energy storage battery 14 and the input end of the low-voltage DC inverter 15. The output end of the energy storage battery 14 is connected to the input end of the low-voltage DC inverter 15. The electric energy generated by the photovoltaic panel 10 can flow into the energy storage battery 14 through the energy storage battery charger 13 to charge the energy storage battery 14. When the energy storage battery 14 is fully charged, the electric energy generated by the photovoltaic panel 10 directly enters the distribution box 12 through the MPPT inverter 11 to provide power to users.

[0020] The output end of the energy storage battery 14 is connected to the input end of the low-voltage DC inverter 15. The low-voltage DC inverter 15 can invert the DC power supplied by the energy storage battery 14 into AC power and output it to the distribution box 12. The current transformer 16 is connected in series to the output live wire L of the low-voltage DC inverter 15. The current transformer 16 can detect the electric energy current passing through the live wire of the low-voltage DC inverter 15. Through the cooperation between the MPPT inverter 11 and the current transformer 16, the output end of the MPPT inverter 11 can be effectively prevented from generating a voltage shock to the low-voltage DC inverter 15, thereby effectively improving safety and extending the service life of the low-voltage DC inverter 15.

[0021] The output end of the distribution box 12 is connected to the national grid. The user can connect the distribution box 12 to the national grid and use the national grid as a hot backup. When the user is using electricity normally, the photovoltaic panel 10 supplies power to the user through the MPPT inverter 11 or the energy storage battery 14 through the low-voltage DC inverter 15. When the independent photovoltaic grid-connected power generation system fails, the distribution box 12 switches the power supply to the national grid, and the national grid continues to supply power to the user, preventing the user from being unable to use electricity when the independent photovoltaic grid-connected power generation system fails, effectively ensuring uninterrupted power supply to the user, and improving the reliability and safety of the independent photovoltaic grid-connected power generation system.

[0022] The specific usage and function of this embodiment are as follows: the user can connect the output end of the photovoltaic panel 10 to the input end of the MPPT inverter 11 and the energy storage battery charger 13 through a wire. After the connection is completed, the output end of the MPPT inverter 11 is connected to the input end of the distribution box 12 through a wire, and the output end of the energy storage battery charger 13 is connected to the input end of the low-voltage DC inverter 15 and the energy storage battery 14 through a wire respectively. The output end of the energy storage battery 14 is also connected to the input end of the low-voltage DC inverter 15. A current transformer 16 is installed on the live wire from the low-voltage DC inverter 15 to the distribution box 12. During the day, the photovoltaic panel 10 generates electricity, most of which is converted into 220V AC power by the MPPT inverter 11 and enters the distribution box. The electricity is stored in the electrical box 12 for users to use, and a small amount of electricity flows into the energy storage battery 14 through the energy storage battery charger 13. Through the regulation of electricity by the distribution box 12, when the power generation power of the photovoltaic panel 10 is greater than the power used by the user, the excess electricity is stored in the energy storage battery 14 until the energy storage battery 14 is fully charged; when the power generation power of the photovoltaic panel 10 is less than the power used by the user, the energy storage battery 14 transmits electricity to the outside through the low-voltage DC inverter 15, and transmits electricity to the distribution box 12 at the same time as the MPPT inverter 11 for users to use. At night, the photovoltaic panel 10 does not generate electricity, and the electricity required by the user is converted from DC to AC by the energy storage battery 14 through the low-voltage DC inverter 15 and then output to the distribution box 12 to continue to provide power to the user.

[0023] The embodiments of the present invention are provided for purposes of illustration and description and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for specific applications.

Claims

1. The sine wave inverter simulates the national grid to build an independent photovoltaic grid-connected power generation system, which is characterized by: It includes a photovoltaic panel (10), an MPPT inverter (11), an energy storage battery charger (13), a distribution box (12), a low-voltage DC inverter (15), an energy storage battery (14), and a current transformer (16); The output end of the photovoltaic panel (10) is connected to the input end of the MPPT inverter (11), the output end of the MPPT inverter (11) is connected to the input end of the distribution box (12), the output end of the photovoltaic panel (10) is connected to the input end of the energy storage battery charger (13), the output end of the energy storage battery charger (13) is connected to the input end of the energy storage battery (14), the output end of the energy storage battery (14) is connected to the input end of the low-voltage DC inverter (15), the output end of the low-voltage DC inverter (15) is connected to the input end of the distribution box (12), and the current transformer (16) is connected in series to the output live wire L of the low-voltage DC inverter (15).

2. The sine wave inverter according to claim 1 simulates the national power grid to form an independent photovoltaic grid-connected power generation system, characterized in that: The output end of the energy storage battery charger (13) is respectively connected to the energy storage battery (14) and the input end of the low-voltage DC inverter (15).

3. The sine wave inverter according to claim 1 simulates the national power grid to form an independent photovoltaic grid-connected power generation system, characterized in that: There are a plurality of photovoltaic panels (10) and a plurality of MPPT inverters (11), and each photovoltaic panel (10) corresponds to one MPPT inverter (11).

4. The sine wave inverter according to claim 1 simulates the national power grid to form an independent photovoltaic grid-connected power generation system, characterized in that: The output end of the distribution box (12) is connected to the national power grid.

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