Miniature photovoltaic grid-connected and bidirectional off-grid inversion control device for motor home

Abstract

The utility model discloses a miniature photovoltaic grid-connected and bidirectional off-grid inversion control device for a motor home, which comprises an MCU (Microprogrammed Control Unit) controller, a miniature photovoltaic grid-connected inverter, an off-grid bidirectional inverter, a switch S1 and a switch S2, wherein the input end of the miniature photovoltaic grid-connected inverter is connected with a preset solar module and a living secondary battery; the output end of the miniature photovoltaic grid-connected inverter is connected to the first switch end of the switch S1 and the first switch end of the switch S2, the second switch end of the switch S1 is connected to the first end of AC household electricity, and the second end of the switch S2 is connected to the first input and output end of the off-grid bidirectional inverter. The first input and output end of the off-grid bidirectional inverter is further connected to the second end of the AC household electricity, the second input and output end of the off-grid bidirectional inverter is connected to the living auxiliary battery, and the control end of the switch S1 and the control end of the switch S2 are connected to the MCU controller. The system can reasonably distribute electric energy, can improve the utilization rate of the electric energy, and can realize safe isolation of a power grid end and a battery end.

Description

Technical Field

[0001] This utility model relates to a motorhome power inverter control device, and more particularly to a micro photovoltaic grid-connected and bidirectional off-grid inverter control device for motorhomes. Background Technology

[0002] Traditional RVs typically use solar panels to charge auxiliary batteries to meet their electrical needs. These solar panels generally employ an MPPT (Maximum Power Point Tracking) controller to charge the auxiliary batteries via DC-DC conversion and MPPT. When the auxiliary battery is fully charged and there is no load, the output power is adjusted to zero to protect the battery and prevent overcharging, thus foregoing the solar panel's power generation. In practical applications, when the RV is parked and not used for extended periods, this results in wasted solar panel power, reducing the utilization rate of the RV's photovoltaic power generation. Furthermore, under long-term parking conditions, the auxiliary batteries remain fully charged for extended periods, lacking a proper charging and discharging process, which can damage the battery's activity and negatively impact its lifespan. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a micro photovoltaic grid-connected and bidirectional off-grid inverter control device that can rationally allocate electrical energy, improve the utilization rate of electrical energy, and achieve safe isolation between the grid end and the battery end, in order to address the shortcomings of the existing technology.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0005] A micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs includes an MCU controller, a micro photovoltaic grid-connected inverter, an off-grid bidirectional inverter, a switch S1, and a switch S2. The input terminal of the micro photovoltaic grid-connected inverter is connected to a preset solar panel and a household auxiliary battery. The output terminals of the micro photovoltaic grid-connected inverter are both connected to the first switch terminals of the switches S1 and S2. The second switch terminal of the switch S1 is connected to a first AC household power supply terminal. The second terminal of the switch S2 is connected to the first input / output terminal of the off-grid bidirectional inverter, which is also connected to a second AC household power supply terminal. The second input / output terminal of the off-grid bidirectional inverter is connected to the household auxiliary battery. The control terminals of the switches S1 and S2 are respectively connected to the MCU controller.

[0006] Preferably, the system includes a switch S3, the two terminals of which are connected in series in the line between the micro photovoltaic grid-connected inverter and the auxiliary battery, and the control terminal of the switch S3 is connected to the MCU controller.

[0007] Preferably, it includes a first communication module and a second communication module, wherein the first communication module is connected between the off-grid bidirectional inverter and the MCU controller, and the second communication module is connected between the micro photovoltaic grid-connected inverter and the MCU controller.

[0008] Preferably, both the first communication module and the second communication module are RS485 communication modules.

[0009] Preferably, it includes a BMS data communication module, which is connected between the auxiliary battery and the MCU controller.

[0010] Preferably, it includes a first Hall current sensor and a second Hall current sensor. The first Hall current sensor is used to collect the current on the line between the off-grid bidirectional inverter and the auxiliary battery and transmit it to the MCU controller. The second Hall current sensor is used to collect the current on the line between the off-grid bidirectional inverter and the second terminal of the AC household power supply and transmit it to the MCU controller.

[0011] In the micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs disclosed in this utility model, when no mains power supply is required, the MCU controller controls the mains power switching switch S1 to open and the inverter switching switch S2 to close, entering the off-grid parallel charging control process. When the auxiliary battery is fully charged, the MCU controller controls the mains power switching switch S1 to close and the inverter switching switch S2 to open, entering the grid-connected discharge control process. During this process, based on the principle of micro photovoltaic grid-connected inverter, when the RV is parked and the battery is fully charged, the solar power generation is inverted and connected to the grid for household use. Compared with the prior art, this utility model can switch the input ports of the battery and the photovoltaic grid-connected inverter, thereby inverting the energy of the battery to the grid end, thus meeting the battery discharge needs. It can not only rationally allocate electrical energy, but also improve the energy utilization rate. Furthermore, under the dual-switch control, it can achieve safe isolation between the grid end and the battery end, better meeting the application requirements. Attached Figure Description

[0012] Figure 1 This is a circuit block diagram of the micro photovoltaic grid-connected and bidirectional off-grid inverter control device of this utility model;

[0013] Figure 2 This is a flowchart of the off-grid parallel charging control process for the micro photovoltaic grid-connected and bidirectional off-grid inverter control device of this utility model;

[0014] Figure 3 This is the grid-connected discharge control process of the micro photovoltaic grid-connected and bidirectional off-grid inverter control device of this utility model. Detailed Implementation

[0015] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0016] This utility model discloses a micro-photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs. Please refer to [link / reference]. Figure 1 It includes an MCU controller 1, a micro photovoltaic grid-connected inverter 2, an off-grid bidirectional inverter 3, a switch S1, and a switch S2. The input terminal of the micro photovoltaic grid-connected inverter 2 is connected to a preset solar panel 4 and a household auxiliary battery 5. The output terminals of the micro photovoltaic grid-connected inverter 2 are both connected to the first switch terminals of the switches S1 and S2. The second switch terminal of the switch S1 is connected to the first terminal of the AC household electricity supply. The second terminal of the switch S2 is connected to the first input / output terminal of the off-grid bidirectional inverter 3. The first input / output terminal of the off-grid bidirectional inverter 3 is also connected to the second terminal of the AC household electricity supply. The second input / output terminal of the off-grid bidirectional inverter 3 is connected to the household auxiliary battery 5. The control terminals of the switches S1 and S2 are respectively connected to the MCU controller 1.

[0017] In the above device, when no mains power supply is required, the MCU controller 1 controls the mains power switching switch S1 to open and controls the inverter switching switch S2 to close, according to... Figure 2 As shown, the off-grid parallel charging control process begins. With the auxiliary battery 5 fully charged, the MCU controller 1 controls the mains power switch S1 to close and the inverter switch S2 to open, according to... Figure 3 The process described above involves entering the grid-connected discharge control flow. Based on the principle of micro-photovoltaic grid-connected inverter, when the RV is parked and the battery is fully charged, the solar power is inverted and connected to the grid for household use. Compared with existing technologies, this invention can switch the input ports of the battery and the photovoltaic grid-connected inverter, thereby inverting the battery's energy to the grid to meet the battery's discharge needs. This not only rationally allocates electrical energy but also improves the energy utilization rate. Furthermore, under dual-switch control, it can achieve safe isolation between the grid end and the battery end, thus better meeting application requirements.

[0018] Please see Figure 1 This embodiment includes a switch S3, whose two terminals are connected in series in the line between the micro photovoltaic grid-connected inverter 2 and the auxiliary battery 5. The control terminal of the switch S3 is connected to the MCU controller 1. The main function of the switch S3 is to control the on / off state between the micro photovoltaic grid-connected inverter 2 and the auxiliary battery 5, thereby controlling the charging start / stop of the auxiliary battery 5.

[0019] To achieve operational control of the micro photovoltaic grid-connected inverter 2 and the off-grid bidirectional inverter 3, please refer to [link / reference]. Figure 1 This embodiment includes a first communication module 6 and a second communication module 7. The first communication module 6 is connected between the off-grid bidirectional inverter 3 and the MCU controller 1, and the second communication module 7 is connected between the micro photovoltaic grid-connected inverter 2 and the MCU controller 1.

[0020] As a preferred method of lower-level machine communication, in this embodiment, both the first communication module 6 and the second communication module 7 are RS485 communication modules.

[0021] Based on this, this embodiment includes a BMS data communication module 8, which is connected between the auxiliary battery 5 and the MCU controller 1. The BMS data communication module 8 enables reasonable control of the charging and discharging state of the auxiliary battery 5.

[0022] To enable real-time acquisition of current on the main branch, this embodiment includes a first Hall current sensor 9 and a second Hall current sensor 10. The first Hall current sensor 9 is used to acquire the current on the line between the off-grid bidirectional inverter 3 and the auxiliary battery 5 and transmit it to the MCU controller 1. The second Hall current sensor 10 is used to acquire the current on the line between the off-grid bidirectional inverter 3 and the second terminal of the AC household power supply and transmit it to the MCU controller 1.

[0023] The micro-photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs disclosed in this utility model achieves an IP65 protection rating by utilizing a micro-photovoltaic grid-connected inverter and bidirectional inverter technology, thus ensuring higher reliability. Furthermore, this utility model eliminates the need for a traditional MPPT controller to control RV battery charging, resulting in lower application costs. Additionally, based on the micro-photovoltaic grid-connected inverter technology, this utility model can invert and connect solar power to the grid when the RV is parked and the battery is fully charged, providing electricity for household use. In practical applications, this utility model can periodically switch the input ports of the battery and the photovoltaic grid-connected inverter, achieving timely battery discharge by inverting battery energy to the grid, thereby helping to extend battery life.

[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. All modifications, equivalent substitutions or improvements made within the technical scope of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs, characterized in that, The system includes an MCU controller (1), a micro photovoltaic grid-connected inverter (2), an off-grid bidirectional inverter (3), a switch S1, and a switch S2. The input terminal of the micro photovoltaic grid-connected inverter (2) is connected to a preset solar panel (4) and a household auxiliary battery (5). The output terminals of the micro photovoltaic grid-connected inverter (2) are both connected to the first switch terminal of the switch S1 and the first switch terminal of the switch S2. The second switch terminal of the switch S1 is connected to the first terminal of the AC household electricity supply. The second terminal of the switch S2 is connected to the first input / output terminal of the off-grid bidirectional inverter (3). The first input / output terminal of the off-grid bidirectional inverter (3) is also connected to the second terminal of the AC household electricity supply. The second input / output terminal of the off-grid bidirectional inverter (3) is connected to the household auxiliary battery (5). The control terminals of the switches S1 and S2 are respectively connected to the MCU controller (1).

2. The micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs as described in claim 1, characterized in that, It includes a switch S3, the two terminals of which are connected in series on the line between the micro photovoltaic grid-connected inverter (2) and the auxiliary battery (5), and the control terminal of the switch S3 is connected to the MCU controller (1).

3. The micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs as described in claim 1, characterized in that, It includes a first communication module (6) and a second communication module (7). The first communication module (6) is connected between the off-grid bidirectional inverter (3) and the MCU controller (1), and the second communication module (7) is connected between the micro photovoltaic grid-connected inverter (2) and the MCU controller (1).

4. The micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs as described in claim 3, characterized in that, Both the first communication module (6) and the second communication module (7) are RS485 communication modules.

5. The micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs as described in claim 1, characterized in that, It includes a BMS data communication module (8), which is connected between the auxiliary battery (5) and the MCU controller (1).

6. The micro photovoltaic grid-connected and bidirectional off-grid inverter control device for RVs as described in claim 1, characterized in that, It includes a first Hall current sensor (9) and a second Hall current sensor (10). The first Hall current sensor (9) is used to collect the current on the line between the off-grid bidirectional inverter (3) and the auxiliary battery (5) and transmit it to the MCU controller (1). The second Hall current sensor (10) is used to collect the current on the line between the off-grid bidirectional inverter (3) and the second terminal of the AC household power supply and transmit it to the MCU controller (1).

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