Multi-energy off-grid type wind-solar-diesel storage and charging micro-grid system

Abstract

The utility model discloses a multi-energy off-grid type wind-light-diesel storage and charging micro-grid system, which comprises a photovoltaic assembly, a wind driven generator, a diesel generator, a power grid and wind-light-diesel storage and charging equipment, and the wind-light-diesel storage and charging equipment comprises MPPT, an energy storage battery, a wind power converter, an energy storage converter, a charging pile, an on-grid and off-grid switching device and a dual-power change-over switch. The photovoltaic module is connected with the MPPT, the wind driven generator is connected with the wind power converter, the energy storage converter is connected with the grid-connected and off-grid switching device, and the wind power converter, the energy storage battery, the MPPT, the energy storage converter and the charging pile are converged and connected through a direct current bus. The multi-energy direct-current coupling mode of photovoltaic power generation, wind power generation, oil engine power generation, a power grid and the like is adopted, the power grid or a diesel generator can be used in extreme weather, wind power or photovoltaic power can be used in an area without power grid coverage or with an unstable power grid, and when the power grid and the diesel generator cannot be used, the function of an energy storage battery can be used; and reliable power supply can be provided under any condition.

Description

Technical Field

[0001] The utility model relates to a multi-energy off-grid wind, solar, diesel storage and charging microgrid system. Background Art

[0002] With global warming and increasingly severe environmental issues, governments around the world have prioritized the development of green energy. The new energy vehicle industry has experienced rapid global growth in recent years. As the number of electric vehicles continues to grow, so too has the demand for charging infrastructure. However, traditional charging methods present numerous challenges, such as long charging times, insufficient charging infrastructure, and significant power load fluctuations. The emergence of solar-to-storage charging systems offers a more convenient, efficient, and reliable charging method for new energy vehicles, driving further growth in the industry. However, these systems cannot provide reliable power supply in remote mountainous areas, islands, and other areas without or with unstable power grids. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a multi-energy off-grid wind-solar-diesel storage and charging microgrid system that adopts multi-energy DC coupling such as photovoltaic power generation, wind power generation, diesel power generation and power grid to provide reliable power supply under any circumstances.

[0004] The purpose of the utility model is achieved through the following technical solutions: a multi-energy off-grid wind, solar, diesel and storage microgrid system, comprising photovoltaic modules, wind turbines, diesel generators, power grids and wind, solar, diesel and storage equipment, the wind, solar, diesel and storage equipment including MPPT, energy storage battery, wind power converter, energy storage converter, charging pile, grid-connected and off-grid switching device, and dual power supply switch;

[0005] The PV panels are connected to the MPPT, which collects the electrical energy from the PV panels onto the DC bus.

[0006] The wind turbine is connected to the wind converter, which converts the AC power generated by the wind turbine into DC power and aggregates it onto the DC bus.

[0007] The energy storage converter is connected to the on-grid and off-grid switching device, which connects the diesel generator and the power grid via a dual power supply switch. The energy storage converter converts the AC power from the power grid or diesel generator into DC power and aggregates it onto the DC bus. Alternatively, it inverts the DC power provided on the DC bus into AC power to power external loads.

[0008] The wind turbine converter, energy storage battery, MPPT, energy storage converter and charging pile are connected through a DC bus.

[0009] The beneficial effects of the present invention are as follows: the present invention adopts a multi-energy DC coupling method including photovoltaic power generation, wind power generation, diesel engine power generation and power grid, and can use clean energy such as wind power and photovoltaic power generation, and can also be supplemented by power grid or diesel generator, and can also store electric energy through energy storage batteries. When wind power or photovoltaic power generation cannot be used in extreme weather, power grid or diesel generator can be used for energy supply. Wind power or photovoltaic power generation can be used in areas without power grid coverage or unstable power grid. When both are unavailable, the energy storage battery function can be used. The present system can provide reliable power supply under any circumstances. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a structural diagram of the multi-energy off-grid wind-solar-diesel storage-charging microgrid system of the utility model;

[0011] Figure 2 This is a structural diagram of the on-grid and off-grid switching device. DETAILED DESCRIPTION

[0012] The technical solution of the present utility model is further described below with reference to the accompanying drawings.

[0013] like Figure 1 As shown, the utility model is a multi-energy off-grid wind, solar, diesel storage and charging microgrid system, which includes photovoltaic modules, wind turbines, diesel generators, power grids and wind, solar, diesel storage and charging equipment. The wind, solar, diesel storage and charging equipment includes MPPT (photovoltaic controller), energy storage batteries, wind power converters, energy storage converters, charging piles, grid-connected and off-grid switching devices, and dual power supply switches;

[0014] The PV panels are connected to the MPPT, which collects the power from the PV panels onto the DC bus. This power is then used to supply power to important loads via the PCS, or to charge energy storage batteries and provide power to charging stations via the DC bus.

[0015] The wind turbine is connected to the wind converter, which converts the AC power generated by the wind turbine into DC power and aggregates it onto the DC bus.

[0016] The energy storage converter is connected to the on-grid and off-grid switching device, which connects the diesel generator and the power grid via a dual power supply switch. The energy storage converter converts the AC power from the power grid or diesel generator into DC power and aggregates it onto the DC bus. Alternatively, it inverts the DC power provided on the DC bus into AC power to power external loads.

[0017] The wind turbine converter, energy storage battery, MPPT, energy storage converter and charging pile are connected through a DC bus.

[0018] Photovoltaic power generation system: used to convert solar energy into electrical energy.

[0019] Energy storage battery: used to store and release electrical energy.

[0020] Wind converter: used to convert the electricity generated by wind turbines into direct current.

[0021] Power storage converter (PCS): used to convert AC power into DC power and DC power into AC power. The PCS is connected to important loads in the microgrid system to provide power to these loads.

[0022] On-grid and off-grid switching device: used for switching between on-grid and off-grid operation. When there is a power grid or the diesel engine is working, it switches to the on-grid state. When there is no power grid in the area, it automatically switches to the off-grid mode. Important loads such as lighting, communication, monitoring and domestic electricity can be connected to the on-grid and off-grid switching device.

[0023] Dual power transfer switch: used for switching between the master and slave power sources of the two power sources, switching between the grid and the diesel generator. When there is a grid, the grid power is used first. When there is a power outage or there is no grid in the area, the diesel generator is used for power generation.

[0024] Charging piles use DC input to connect multiple energy sources, including photovoltaic power generation, wind power generation, energy storage batteries, the grid, or diesel engines, to charge vehicles through the charging pile system. The charging piles use DC input to couple photovoltaic, wind power, and energy storage batteries on the DC side, reducing energy loss. When operating off-grid, the on-grid switching device can provide AC power to power critical loads.

[0025] like Figure 2 As shown, the on-grid switching device (STS) includes a fan, a load current sampling circuit connected to the load, a communication / light board circuit, an STS auxiliary source, a load-side voltage / current sampling circuit, a grid-side voltage sampling circuit, a drive board, a control board and a thyristor switch (SCR). The control board is respectively connected to the load-side voltage / current sampling circuit, the grid-side voltage sampling circuit, the load current sampling circuit, the communication / light board circuit, and the drive board; the load-side voltage / current sampling circuit is used to collect the voltage or current of the grid converted by the PCS, and the grid-side voltage sampling circuit is used to collect the voltage of the grid provided by the grid / diesel generator; the STS auxiliary source is respectively connected to the control board and the drive board to power the two; the drive board is connected to the thyristor switch, and the grid / diesel generator and the energy storage converter are respectively connected to the thyristor switch, and the drive board controls the thyristor switch (SCR) to select the PCS (energy storage converter) or the grid / diesel generator to power the load, and the load is connected to the PCS.

[0026] The driver board primarily performs the following functions: 1. Signal processing and control: The driver board receives various command signals from the control board, including switching instructions and status monitoring requests. For example, if the primary power supply fails, the control system signals a switch to the backup power source. Upon receiving this signal, the driver board triggers the subsequent switching action. 2. Driving the transfer switch: The driver board provides the transfer switch (SCR) with action information, enabling it to quickly and accurately switch between the grid and load power. For example, when a power source switch is required, the driver board outputs a certain current and voltage to actuate the transfer switch quickly to ensure power continuity.

[0027] The diesel generator and the grid are connected to the input side of a dual-power transfer switch, while the output side of the dual-power transfer switch is connected to a grid-connected / off-grid switching device. From the perspective of the grid-connected / off-grid switching device, it doesn't matter whether the power is coming from the grid or the diesel generator; it only considers the grid on the AC side of the grid-connected / off-grid switching device to be alive. My auxiliary power source draws power from both the load side and the AC grid side, which is then internally rectified into the low-voltage DC power required by the control board. If I draw power only from the AC grid side, my grid-connected / off-grid switching device will not function if the grid goes out.

[0028] The auxiliary power source is connected to the PCS and the grid / diesel generator respectively, and can obtain electricity from either the PCS or the grid / diesel generator. The dual power supply mode can ensure the stable operation of the device. Grid-side power supply guarantee: The grid / diesel generator can usually provide a relatively stable power supply. Under normal circumstances, the grid-side auxiliary power supply can provide reliable power support for the on-grid and off-grid switching device. When the entire power system is in a grid-connected state, the power supply on the grid side is sufficient and relatively stable, which can ensure the normal operation of the switching device, monitor the grid status at any time, and prepare for switching operations. Load-side power supply supplement: Load-side power supply serves as a supplementary auxiliary power source and plays an important role in specific situations. For example, when a grid failure occurs or off-grid switching is required, even if the grid-side power supply is interrupted, the load-side power supply can maintain the basic operation of the switching device, ensuring that the switching process can proceed smoothly and avoiding switching failures due to auxiliary power interruptions.

[0029] A PCS behaves as a current source when connected to the grid and as a voltage source when off-grid. A PCS can exhibit different power characteristics depending on its operating mode. When connected to the grid, the PCS primarily relies on the grid's voltage and frequency as a reference, acting as a current source.

[0030] However, when off-grid operation is required, the PCS must be able to independently provide voltage and frequency support to ensure stable system operation. At this point, the PCS switches to grid-forming mode, acting as a voltage source. In this mode, the PCS internally sets voltage parameter signals and outputs voltage and frequency to support off-grid power supply. This mode transition allows the PCS to both assist in grid-connected operation and provide the necessary voltage and frequency support as an independent power source when off-grid.

[0031] When the On-Off Switching System (STS) switches to the grid, the load is powered by the grid, and the PCS is either charging or discharging. If the grid loses power and the STS does not switch, the PCS will detect the grid loss and trigger the islanding protection function, which will immediately stop the operation to prevent power from being fed back into the grid and causing electric shock.

[0032] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can, based on the technical teachings disclosed in this utility model, make various other specific variations and combinations that do not depart from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A multi-energy off-grid wind, solar, diesel and storage microgrid system, characterized by: It includes photovoltaic modules, wind turbines, diesel generators, power grids and wind, solar, diesel and storage equipment. The wind, solar, diesel and storage equipment includes MPPT, energy storage batteries, wind turbine converters, energy storage converters, charging piles, grid-connected and off-grid switching devices, and dual power supply switches. The PV panels are connected to the MPPT, which collects the electrical energy from the PV panels onto the DC bus. The wind turbine is connected to the wind converter, which converts the AC power generated by the wind turbine into DC power and aggregates it onto the DC bus. The energy storage converter is connected to the on-grid and off-grid switching device, which connects the diesel generator and the power grid via a dual power supply switch. The energy storage converter converts the AC power from the power grid or diesel generator into DC power and aggregates it onto the DC bus. Alternatively, it inverts the DC power provided on the DC bus into AC power to power external loads. The wind turbine converter, energy storage battery, MPPT, energy storage converter and charging pile are connected through a DC bus.

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