Hybrid inverter grid capable of simultaneously outputting single-phase and three-phase electric power of the same capacity

Abstract

This invention provides a hybrid inverter grid capable of simultaneously outputting the same capacity of single-phase and three-phase power. It includes a DC power supply module, a DC bus, a three-phase AC bus, a three-phase inverter circuit, and a single-phase output module. The three-phase inverter circuit converts DC power into three-phase AC power, and the single-phase output module converts three-phase AC power into single-phase AC power. The DC power supply module integrates a photovoltaic power generation array and energy storage batteries, optimizing energy management. This invention avoids single-phase port overload and thermal stress accumulation problems, significantly extending the lifespan of power devices; it eliminates the need for additional independent inverters or complex conversion equipment, reducing system cost and complexity; and it offers flexible and stable off-grid switching, adapting to various application scenarios such as residential users, industrial users, and areas with weak power grids. This grid improves power quality and supply stability.

Description

Technical Field

[0001] This utility model relates to the field of new energy power supply technology, specifically to a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy. Background Technology

[0002] With the accelerated global energy structure transformation, photovoltaic (PV) power generation technology, as the most representative form of new energy, has achieved large-scale application and is gradually penetrating from industrial scenarios to residential users. Especially in areas with weak grid infrastructure and at the ends of the grid where power quality is poor, PV + energy storage synergistic systems and grid-complementary power supply modes have developed into an effective solution to address power continuity issues. This mode can not only maintain the stable operation of critical loads under abnormal grid conditions, but also significantly improve regional power quality through intelligent dispatching, thereby promoting the deep integration of clean energy systems with people's livelihood needs.

[0003] However, current technical solutions have revealed compatibility issues with key equipment in actual deployments. Mainstream three-phase inverters, limited by their inherent topology, must forcibly maintain three-phase current balance, resulting in a maximum output power limit of 33.3% of the total capacity for a single-phase port. When a single-phase high-power inductive load (such as an asynchronous motor or compressor) is connected to the system, the 5-7 times inrush current generated during startup will directly cause instantaneous overload of the single-phase port. This condition will trigger malfunctions in the inverter's overload protection device, causing unplanned system shutdowns. More seriously, periodic inrush loads can induce thermal stress accumulation in power devices. Experiments have shown that when the single-phase inrush current exceeds 300% of the rated value, the IGBT junction temperature rises at a rate of 15°C per second, shortening device lifespan by more than 60%, ultimately leading to safety hazards such as equipment lifespan degradation and insulation performance deterioration.

[0004] Furthermore, in the existing power grid architecture, for scenarios requiring the simultaneous use of single-phase and three-phase power, it is often necessary to configure independent single-phase and three-phase inverters, or to employ complex circuit conversion equipment to meet the needs of single-phase and three-phase loads separately. This not only increases the complexity and cost of the system but also reduces its reliability and operating efficiency. Moreover, in existing technologies, there are certain issues with power quality control and equipment compatibility during grid-connected and off-grid switching applications. Voltage fluctuations and current surges during switching can easily occur, affecting the normal operation of the load and the lifespan of the equipment.

[0005] In summary, there is an urgent need in the field of new energy power supply systems for a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase power. This would address issues such as limited single-phase power, high equipment overload risk, high system complexity, high cost, unstable grid-connected / off-grid switching, and imperfect energy management and energy storage integration of DC power modules. Ultimately, this would provide users with a more efficient, reliable, and flexible power supply solution. Utility Model Content

[0006] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.

[0007] Therefore, this utility model provides a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy.

[0008] This utility model provides a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy, comprising: DC power module, used to provide DC power; A DC bus, connected to the DC power module, is used to transmit DC power. The three-phase AC busbar is connected to the grid input and is used to transmit three-phase AC power. A three-phase inverter circuit has an input terminal and an output terminal. The input terminal of the three-phase inverter circuit is connected to a DC bus, and the output terminal of the three-phase inverter circuit is coupled to a three-phase AC bus. The three-phase inverter circuit is used to convert DC power into three-phase AC power. A single-phase output module has a first terminal and a second terminal. The first terminal of the single-phase output module is connected to a three-phase AC bus. The single-phase output module is used to convert three-phase AC power into single-phase AC power. The second terminal of the single-phase output module serves as the single-phase output terminal of the grid structure to output single-phase AC power. Among them, one end of the three-phase AC bus is led out as the three-phase output terminal of the grid to output three-phase AC power.

[0009] The hybrid inverter grid structure capable of simultaneously outputting the same capacity of single-phase and three-phase electrical energy according to the above-mentioned technical solution of this utility model may also have the following additional technical features: In the above technical solution, the single-phase output module includes: A rectifier circuit has a first terminal and a second terminal. The first terminal of the rectifier circuit is coupled to the three-phase AC bus. The rectifier circuit is used to rectify the three-phase AC power into DC power and output it through its second terminal. A single-phase inverter circuit has a first terminal and a second terminal. The first terminal of the single-phase inverter circuit is connected to the second terminal of the rectifier circuit. The single-phase inverter circuit is used to invert the DC power output by the rectifier circuit into single-phase AC power and output it through its second terminal. The second terminal of the single-phase inverter circuit serves as the second terminal of the single-phase output module.

[0010] The above technical solution also includes: The grid-connected / off-grid switching switch has a first terminal and a second terminal. The first terminal of the grid-connected / off-grid switching switch is coupled to the common terminal of the three-phase output terminal and the first terminal of the single-phase output module, and the second terminal of the grid-connected / off-grid switching switch is connected to the grid input.

[0011] In the above technical solution, the DC power module includes a DC power generation device, which is connected to a DC bus, and the DC power generation device includes a DC wind turbine and / or a photovoltaic power generation array.

[0012] In the above technical solution, the DC power supply module includes: A photovoltaic power generation array is used to convert light energy into direct current electrical energy and transmit it to the DC bus; The MPPT control unit is located between the photovoltaic power generation array and the DC bus to regulate the photovoltaic power generation array so that it is always in the maximum power output state.

[0013] In the above technical solution, the DC power supply module further includes: The energy storage battery is connected to the DC bus, and the DC power generation device can charge the energy storage battery and output DC power to the three-phase inverter circuit through the DC bus.

[0014] The above technical solution also includes: An AC / DC charging circuit has a first terminal and a second terminal. The first terminal of the AC / DC charging circuit is connected to a three-phase AC bus, and the second terminal of the AC / DC charging circuit is connected to a DC bus. The AC / DC charging circuit is used to convert three-phase AC power into DC power and charge the energy storage battery.

[0015] The above technical solution also includes: A charging switch is located between the first terminal of the AC / DC charging circuit and the three-phase AC bus.

[0016] In the above technical solution, the charging switch has a first end and a second end. The first end of the charging switch is connected to the first end of the AC / DC charging circuit, and the second end of the charging switch is coupled between the grid input and the second end of the grid-connected / off-grid switching switch.

[0017] In the above technical solution, the single-phase output terminal is connected to a single-phase current load, which includes motor-type loads.

[0018] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of this utility model are: This hybrid inverter grid can simultaneously output the same capacity of single-phase and three-phase power, solving the problem of limited single-phase power in traditional three-phase inverters. Through the design of the single-phase output modules, it avoids problems such as single-phase port overload, inverter overload protection device malfunction, and thermal stress accumulation in power devices when high-power single-phase inductive loads are connected, effectively extending device life and improving system reliability. Simultaneously, this grid can adapt to various application scenarios without the need for additional independent single-phase and three-phase inverters or complex conversion equipment, simplifying the system architecture and reducing costs. In terms of grid-connected / off-grid switching, it enables flexible switching with the grid, ensuring normal load operation and improving power quality and system stability. Furthermore, the DC power supply module integrates multiple energy forms, optimizing energy management and improving overall energy utilization efficiency and power supply stability.

[0019] Specifically, this hybrid inverter grid can simultaneously output the same capacity of single-phase and three-phase power. The three-phase inverter circuit efficiently converts DC power into three-phase AC power to meet the power requirements of three-phase loads; the single-phase output module further converts the power on the three-phase AC bus into single-phase AC power output, and the single-phase output capacity is no longer limited by the power limitation of the single-phase port of the traditional three-phase inverter (33.3% of the total system capacity), which can fully utilize the total capacity of the inverter grid, improve power utilization efficiency, and meet the power requirements of more types of loads.

[0020] Compared to traditional solutions, this application avoids problems such as single-phase port overload, inverter overload protection device malfunction, and thermal stress accumulation in power devices caused by connecting high-power inductive loads in a single phase. It significantly reduces the junction temperature rise rate of power devices such as IGBTs, effectively extending device lifespan, reducing equipment failures caused by overload or thermal stress, improving overall system reliability, and lowering equipment maintenance costs and replacement frequency. In practical engineering applications, connecting motor-type loads to the single-phase output terminal offers the advantage of obtaining the same single-phase power output as three-phase power, avoiding the problem of overload on any single-phase output caused by connecting to any three-phase load.

[0021] In terms of grid connection and off-grid switching, this application enables flexible switching with the power grid through a grid connection and off-grid switching switch. When connected to the grid, it can provide complementary power supply to the grid, and when off-grid, it can independently supply power to the load, adapting to various application scenarios, such as residential users, industrial users, and areas with weak power grids, thereby improving the system's compatibility and power supply continuity.

[0022] Additional aspects and advantages of this invention will become apparent in the description that follows, or may be learned by practice of this invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a circuit diagram of a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy according to one embodiment of the present invention. Detailed Implementation

[0024] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0025] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0026] The following reference Figure 1 This invention describes a hybrid inverter grid structure that can simultaneously output the same capacity of single-phase and three-phase electrical energy, according to some embodiments of the present invention.

[0027] Some embodiments of this application provide a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy.

[0028] like Figure 1 As shown, the first embodiment of this utility model proposes a hybrid inverter grid that can simultaneously output the same capacity of single-phase and three-phase electrical energy, including: a DC power supply module, a DC bus, a three-phase AC bus, a three-phase inverter circuit, and a single-phase output module.

[0029] The DC power module is used to provide DC power; specifically, the DC power module includes a DC power generation device, which is connected to a DC bus. The DC power generation device can be one or more power generation devices capable of providing DC power, such as a DC wind turbine and a photovoltaic power generation array; in this disclosure, the DC power generation device adopting a photovoltaic power generation array is used as an example for illustration.

[0030] The DC bus is connected to the DC power supply module and is used to transmit DC power. The three-phase AC bus is connected to the grid input and is used to transmit three-phase AC power. One end of the three-phase AC bus serves as the three-phase output terminal of the grid, outputting three-phase AC power. The three-phase inverter circuit has an input terminal and an output terminal. The input terminal of the three-phase inverter circuit is connected to the DC bus, and the output terminal of the three-phase inverter circuit is coupled to the three-phase AC bus. The three-phase inverter circuit is used to convert DC power into three-phase AC power. It is understood that the three-phase inverter circuit in this disclosure can be any of the existing three-phase inverter circuits, such as a half-bridge inverter circuit, a full-bridge inverter circuit, etc. The specific circuit structure is known to those skilled in the art and can be selected according to specific needs, and will not be described in detail here.

[0031] The single-phase output module has a first terminal and a second terminal. The first terminal of the single-phase output module is connected to the three-phase AC bus. The single-phase output module is used to convert three-phase AC power into single-phase AC power. The second terminal of the single-phase output module serves as the single-phase output terminal of the grid structure to output single-phase AC power.

[0032] Based on the above configuration, in the single-phase full-load output mode, the output capacity of the single-phase output terminal can be ≥50% of the total system capacity, significantly exceeding the limitation of the traditional inverter's single-phase output port ≤33.3% of the total system capacity. Furthermore, compared to the requirement for strict three-phase balance in traditional inverter grids, the grid structure disclosed herein allows for ±20% instantaneous imbalance.

[0033] In some embodiments, the single-phase output module includes a rectifier circuit and a single-phase inverter circuit.

[0034] The rectifier circuit has a first terminal and a second terminal. The first terminal of the rectifier circuit is coupled to the three-phase AC bus. The rectifier circuit is used to rectify the three-phase AC power into DC power and output it through its second terminal. The single-phase inverter circuit has a first terminal and a second terminal. The first terminal of the single-phase inverter circuit is connected to the second terminal of the rectifier circuit. The single-phase inverter circuit is used to invert the DC power output by the rectifier circuit into single-phase AC power and output it through its second terminal. The second terminal of the single-phase inverter circuit serves as the second terminal of the single-phase output module.

[0035] Specifically, the same power single-phase AC power is generated by first rectifying the three-phase AC power into DC power, and then generating single-phase AC power through a single-phase inverter circuit. This allows the maximum output power of the single-phase output terminal to be basically the same as the power of the three-phase inverter circuit (ignoring losses). In addition, this disclosure does not affect the use of the three-phase load output channel while outputting a single-phase load. The single-phase load output channel and the three-phase load output channel can simultaneously output the same rated power of three-phase power and single-phase power.

[0036] In some embodiments, the hybrid inverter grid also includes a grid-connected / off-grid switching switch.

[0037] The grid-connected / off-grid transfer switch has a first terminal and a second terminal. The first terminal of the grid-connected / off-grid transfer switch is coupled to the common terminal of the three-phase output terminal and the first terminal of the single-phase output module, and the second terminal of the grid-connected / off-grid transfer switch is connected to the grid input. This enables the hybrid inverter grid structure to switch between grid-connected and off-grid operation. When connected to the grid, the grid-connected / off-grid transfer switch is closed; when disconnected from the grid, the grid-connected / off-grid transfer switch is open. In both grid-connected and off-grid modes, it supports the same rated power output of three-phase and single-phase power.

[0038] In one specific embodiment, the DC power module includes a photovoltaic power generation array and an MPPT control unit. The photovoltaic power generation array is used to convert light energy into DC electrical energy and transmit it to the DC bus; the MPPT control unit is located between the photovoltaic power generation array and the DC bus and is used to adjust the photovoltaic power generation array so that it is always in the maximum power output state.

[0039] In some embodiments, the DC power module further includes an energy storage battery connected to the DC bus, and the DC power generation device can charge the energy storage battery and output DC power to the three-phase inverter circuit through the DC bus.

[0040] In some embodiments, the hybrid inverter grid also includes an AC / DC charging circuit.

[0041] Specifically, the AC / DC charging circuit has a first terminal and a second terminal. The first terminal of the AC / DC charging circuit is connected to the three-phase AC bus, and the second terminal of the AC / DC charging circuit is connected to the DC bus. The AC / DC charging circuit is used to convert three-phase AC power into DC power and charge the energy storage battery.

[0042] In some embodiments, the hybrid inverter grid also includes a charging switch. The charging switch is disposed between the first terminal of the AC / DC charging circuit and the three-phase AC bus.

[0043] In one specific embodiment, the charging switch has a first terminal and a second terminal. The first terminal of the charging switch is connected to the first terminal of the AC / DC charging circuit, and the second terminal of the charging switch is coupled between the grid input and the second terminal of the grid-connected / off-grid switching switch. This enables, under certain specific conditions, even when the grid is off-grid, the energy storage battery can still be charged via the grid by closing the charging switch.

[0044] In some embodiments, the single-phase output terminal is connected to a single-phase current load, which includes a motor-type load.

[0045] In one specific embodiment, a villa uses a conventional three-phase inverter with a power of 10kW. The single-phase output power is only 1 / 3 of the rated power. The rated power of a water pump motor is 2kW. If any single phase is connected, if a surge current of 5-7 times the rated power is generated at the moment of startup, it will cause single-phase overload and the inverter will not work properly.

[0046] If the hybrid inverter grid structure of this utility model is used, and the pumping motor is connected to the single-phase output terminal, the maximum power of the single-phase output terminal is 10kW. Even if a 2kW pumping motor generates an inrush current of 5-7 times the current at the moment of startup, the hybrid inverter grid structure can still work normally without overload problems.

[0047] Specifically, when the 2kW water pump (cosφ=0.8) starts, the traditional inverter triggers overcurrent protection within 58ms; this solution maintains a three-phase voltage distortion rate of <5% during the output of a 13kVA inrush current (6.5 times), and the system continues to operate normally.

[0048] In another application scenario, such as electric vehicle charging stations, the single-phase output can be connected to a 7kW charging station, while the three-phase output can power the air conditioning system. The total utilization rate can reach 90%, which is 37% higher than the traditional solution.

[0049] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model shall be included within the protection scope of this utility model.

Claims

1. A hybrid inverter grid frame capable of simultaneously outputting single-phase and three-phase electric power of the same capacity, characterized in that, include: DC power module, used to provide DC power; A DC bus, connected to the DC power module, is used to transmit DC power. The three-phase AC busbar is connected to the grid input and is used to transmit three-phase AC power. A three-phase inverter circuit has an input terminal and an output terminal. The input terminal of the three-phase inverter circuit is connected to a DC bus, and the output terminal of the three-phase inverter circuit is coupled to a three-phase AC bus. The three-phase inverter circuit is used to convert DC power into three-phase AC power. A single-phase output module has a first terminal and a second terminal. The first terminal of the single-phase output module is connected to a three-phase AC bus. The single-phase output module is used to convert three-phase AC power into single-phase AC power. The second terminal of the single-phase output module serves as the single-phase output terminal of the grid structure to output single-phase AC power. Among them, one end of the three-phase AC bus is led out as the three-phase output terminal of the grid to output three-phase AC power.

2. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 1, wherein, The single-phase output module includes: A rectifier circuit has a first terminal and a second terminal. The first terminal of the rectifier circuit is coupled to the three-phase AC bus. The rectifier circuit is used to rectify the three-phase AC power into DC power and output it through its second terminal. A single-phase inverter circuit has a first terminal and a second terminal. The first terminal of the single-phase inverter circuit is connected to the second terminal of the rectifier circuit. The single-phase inverter circuit is used to invert the DC power output by the rectifier circuit into single-phase AC power and output it through its second terminal. The second terminal of the single-phase inverter circuit serves as the second terminal of the single-phase output module.

3. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 2, characterized in that, Also includes: The grid-connected / off-grid switching switch has a first terminal and a second terminal. The first terminal of the grid-connected / off-grid switching switch is coupled to the common terminal of the three-phase output terminal and the first terminal of the single-phase output module, and the second terminal of the grid-connected / off-grid switching switch is connected to the grid input.

4. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 3, characterized in that, The DC power module includes a DC power generation device connected to a DC bus, and the DC power generation device includes a DC wind turbine and / or a photovoltaic power generation array.

5. The hybrid inverter grid structure capable of simultaneously outputting the same capacity of single-phase and three-phase electrical energy according to claim 3, characterized in that, The DC power supply module includes: A photovoltaic power generation array is used to convert light energy into direct current electrical energy and transmit it to the DC bus; The MPPT control unit is located between the photovoltaic power generation array and the DC bus to regulate the photovoltaic power generation array so that it is always in the maximum power output state.

6. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 4, wherein, The DC power supply module also includes: The energy storage battery is connected to the DC bus, and the DC power generation device can charge the energy storage battery and output DC power to the three-phase inverter circuit through the DC bus.

7. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 6, wherein, Also includes: An AC / DC charging circuit has a first terminal and a second terminal. The first terminal of the AC / DC charging circuit is connected to a three-phase AC bus, and the second terminal of the AC / DC charging circuit is connected to a DC bus. The AC / DC charging circuit is used to convert three-phase AC power into DC power and charge the energy storage battery.

8. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 7, wherein, Also includes: A charging switch is located between the first terminal of the AC / DC charging circuit and the three-phase AC bus.

9. The hybrid grid-tie inverter capable of simultaneously outputting single-phase and three-phase electric power with the same capacity according to claim 8, wherein, The charging switch has a first terminal and a second terminal. The first terminal of the charging switch is connected to the first terminal of the AC / DC charging circuit, and the second terminal of the charging switch is coupled between the grid input and the second terminal of the grid-connected / off-grid switching switch.

10. The hybrid grid-tie inverter capable of simultaneously outputting single phase and three phase electric power of the same capacity according to claim 1, wherein, The single-phase output is connected with a single-phase current load, and the single-phase current load includes a motor-type load.

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