Sensing-free rapid switching switching device

Abstract

The utility model discloses a non-perception rapid switching device, which comprises an STM32 microprocessor, an RN8302B three-phase electric energy metering chip, a power supply module, a photovoltaic end power monitoring module, a load end power monitoring module, a three-phase combination switch module, a man-machine interaction module, a 4G communication module and a TF card storage module. The device can realize optimal matching of photovoltaic power generation and electrical load, and fully exerts the direct application efficiency of photovoltaic power generation.

Description

Technical Field

[0001] This utility model discloses a seamless and rapid switching device, belonging to the field of power technology. Background Technology

[0002] Distributed photovoltaic (PV) technology, as an emerging energy technology, can simultaneously meet energy demand, reduce the greenhouse effect, and improve power supply reliability, making it an important direction for the future development of global energy technology. With increasingly mature PV power generation technology and gradually decreasing costs, it is becoming a beneficial supplement to conventional energy sources and is widely used in special fields, such as meeting the electricity needs of residents in remote, unpowered areas. However, in recent years, the large-scale integration of distributed PV into distribution networks has also caused voltage exceeding limits, poor reactive power regulation capabilities, and regional power quality harmonic exceedances in some areas. This has led to voltage fluctuations and flicker in the distribution network system, and the uncertainty of power output can cause changes in distribution network load flow, making it difficult to control voltage levels and other related problems. Therefore, research on low-voltage, fast, and seamless switching technology based on PV power prediction is a key technical issue that urgently needs to be addressed in the current new power system. Utility Model Content

[0003] To address the aforementioned issues, this invention proposes a seamless and rapid switching device that can achieve optimal matching between photovoltaic power generation and electrical load, thereby maximizing the direct application efficiency of photovoltaic power generation.

[0004] The technical solution of this utility model is as follows:

[0005] A seamless and rapid switching device includes an STM32 microprocessor, an RN8302B three-phase power metering chip, a power supply module, a photovoltaic power monitoring module, a load power monitoring module, a three-phase composite switch module, a human-machine interaction module, a 4G communication module, and a TF card storage module.

[0006] The photovoltaic power monitoring module includes a photovoltaic AC voltage acquisition circuit, an on-chip ADC, a photovoltaic AC current acquisition circuit, and a feedthrough current transformer; the STM32 microprocessor uses the feedthrough current transformer to acquire the current signal of the photovoltaic AC current acquisition circuit and uses the on-chip ADC to acquire the voltage signal of the photovoltaic AC voltage acquisition circuit.

[0007] The load-side power monitoring module includes a load AC voltage acquisition circuit, a voltage transformer, a current transformer, and a load AC current acquisition circuit.

[0008] The STM32 microprocessor reads the power signal from the load-side power monitoring module transmitted by the RN8302B three-phase power metering chip. The RN8302B three-phase power metering chip is used to acquire the output signal of the load-side power monitoring circuit, acquire the load voltage signal from the load AC voltage acquisition circuit through a voltage transformer, acquire the load current signal from the load AC current acquisition circuit through a current transformer, and send the load power signal to the STM32 microprocessor via the SPI communication protocol.

[0009] The three-phase composite switch module includes a photovoltaic three-phase switch circuit, a grid three-phase switch circuit, a bidirectional optocoupler MOC3051SM, a magnetic latching relay, a thyristor module, a bidirectional optocoupler PCB81A4, and a level conversion circuit. The STM32 microprocessor outputs a control signal through the level conversion circuit. When the STM32 microprocessor pin outputs a high-level signal, the bidirectional optocoupler MOC3061 is turned on, and either the photovoltaic three-phase switch circuit or the grid three-phase switch circuit supplies power to the switch circuit. The thyristor module is then turned on, and the magnetic latching relay module is turned on, enabling the power supply end to supply power to the load. The function of the bidirectional optocoupler PCB81A4 is to turn on the optocoupler PCB81A4 when there is current in the circuit, and the optocoupler PCB81A4 outputs a high level to the STM32 microprocessor. When the circuit is open and there is no current, the optocoupler is turned off, and the optocoupler PCB81A4 outputs a low level to the STM32 microprocessor. The STM32 microprocessor determines whether the switching action is completed based on the received high and low levels.

[0010] The STM32 microprocessor wirelessly transmits USART interface data to the background display via the 4G communication module, and interacts with the human-machine interaction module; it also saves important data in the TF card storage module via the SDIO interface, so that the data will not be lost after power failure.

[0011] The power supply module includes a BUCK circuit, an LDO circuit, and an AC / DC circuit, which provide power to all of the above modules.

[0012] Preferably, the photovoltaic AC current acquisition circuit uses a LEM DHAB S / 15 type through-hole Hall sensor to acquire the current value of photovoltaic power generation.

[0013] Preferably, the voltage transformer mentioned above is a ZMPT107-1 current-type voltage transformer.

[0014] Preferably, the current transformer mentioned above is an HCT226JY-2 current transformer.

[0015] Preferably, the magnetic latching relay mentioned above is a K88E high-power 120A magnetic latching relay.

[0016] Preferably, the above-mentioned thyristor module adopts the BTA100-1600B high-performance three-terminal bidirectional thyristor.

[0017] The beneficial effects of this invention are as follows: the switching device utilizes the microsecond-level switching performance of bidirectional thyristors to achieve rapid switching, ensuring that electrical equipment operates normally without being detected during the switching process; the parallel connection of two bidirectional thyristors improves the overall operating power of the switching switch; the bidirectional thyristors are driven by an MOC3061 optocoupler, and the magnetic latching relay automatically turns off the thyristors after conduction, reducing thyristor energy loss. This improves the direct utilization rate of photovoltaic power generation, reduces the impact of photovoltaic grid connection on the power quality of the distribution network, and reduces the capacity of energy storage stations. Attached Figure Description

[0018] Figure 1 This is a system block diagram of this utility model;

[0019] Figure 2 This is the minimum system circuit diagram for STM32F104.

[0020] Figure 3 It is a photovoltaic current acquisition circuit;

[0021] Figure 4 It is a photovoltaic voltage acquisition circuit;

[0022] Figure 5 This is the minimum system diagram of the three-phase power metering chip RN8302B;

[0023] Figure 6 It is a load voltage acquisition circuit;

[0024] Figure 7 It is the load current sampling current;

[0025] Figure 8 It is a level conversion circuit;

[0026] Figure 9 It is a magnetic latching relay drive circuit;

[0027] Figure 10 It is a composite switching circuit;

[0028] Figure 11 It is a 4G communication circuit;

[0029] Figure 12 It's a BUCK circuit;

[0030] Figure 13 It is an LDO circuit;

[0031] Figure 14 It is an AC / DC circuit. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0033] like Figure 1 As shown, a seamless and fast switching device includes an STM32 microprocessor, an RN8302B three-phase power metering chip, a power supply module, a photovoltaic power monitoring module, a load power monitoring module, a three-phase composite switch module, a human-machine interaction module, a 4G communication module, and a TF card storage module.

[0034] The photovoltaic power monitoring module includes a photovoltaic AC voltage acquisition circuit, an on-chip ADC, a photovoltaic DC current acquisition circuit, and a feedthrough current transformer; the STM32 microprocessor uses the feedthrough current transformer to acquire the current signal of the photovoltaic DC current acquisition circuit and uses the on-chip ADC to acquire the voltage signal of the photovoltaic DC voltage acquisition circuit.

[0035] The load-side power monitoring module includes a load AC voltage acquisition circuit, a voltage transformer, a current transformer, and a load AC current acquisition circuit.

[0036] The STM32 microprocessor reads the power signal from the load-side power monitoring module transmitted by the RN8302B three-phase power metering chip. The RN8302B three-phase power metering chip is used to acquire the output signal of the load-side power monitoring circuit, acquire the load voltage signal from the load AC voltage acquisition circuit through a voltage transformer, acquire the load current signal from the load AC current acquisition circuit through a current transformer, and send the load power signal to the STM32 microprocessor via the SPI communication protocol.

[0037] The three-phase composite switch module includes a photovoltaic three-phase switch circuit, a grid three-phase switch circuit, a bidirectional optocoupler MOC3051SM, a magnetic latching relay, a thyristor module, a bidirectional optocoupler PCB81A4, and a level conversion circuit. The STM32 microprocessor outputs a control signal through the level conversion circuit. When the STM32 microprocessor pin outputs a high-level signal, the bidirectional optocoupler MOC3061 is turned on, and either the photovoltaic three-phase switch circuit or the grid three-phase switch circuit supplies power to the switch circuit. The thyristor module is then turned on, and the magnetic latching relay module is turned on, enabling the power supply end to supply power to the load. The function of the bidirectional optocoupler PCB81A4 is to turn on the optocoupler PCB81A4 when there is current in the circuit, and the optocoupler PCB81A4 outputs a high level to the STM32 microprocessor. When the circuit is open and there is no current, the optocoupler is turned off, and the optocoupler PCB81A4 outputs a low level to the STM32 microprocessor. The STM32 microprocessor determines whether the switching action is completed based on the received high and low levels.

[0038] The STM32 microprocessor wirelessly transmits USART interface data to the background display via the 4G communication module, and interacts with the human-machine interaction module; it also saves important data in the TF card storage module via the SDIO interface, so that the data will not be lost after power failure.

[0039] The power supply module includes a BUCK circuit, an LDO circuit, and an AC / DC circuit, which provide power to all of the above modules.

[0040] Preferably, the STM32 microprocessor uses STMicroelectronics' STM32F103ZET6 as its core unit, responsible for control, data communication, and signal processing. The STM32F103ZET6 is a high-performance 32-bit microcontroller based on the ARM Cortex-M3 core, featuring rich peripherals and high processing power. This chip has 512KB of Flash memory and 64KB of SRAM, meeting the data storage and processing needs of complex applications. It supports multiple communication interfaces, including USART, I2C, SPI, CAN, and USB, facilitating data exchange and control with external devices. Furthermore, the STM32F103ZET6 is equipped with multiple timers, three 12-bit ADCs, and one 12-bit DAC, enabling precise analog signal processing. The minimum system circuit of the microprocessor is as follows: Figure 2 As shown, it consists of a microprocessor and simple peripheral circuits.

[0041] Preferably, the photovoltaic AC current acquisition circuit described above uses a LEM DHAB S / 15 feedthrough Hall sensor to acquire the current value of photovoltaic power generation. The LEM DHAB S / 15 is a feedthrough Hall sensor that uses open-loop Hall effect technology. It has a measurement accuracy of 1% and a large measurement range, with a theoretical primary-side current of 60A to 600A. It can also operate stably in a wide temperature range of -40℃ to +125℃, and has advantages such as high accuracy, wide measurement range, and good linearity.

[0042] The formula for converting the acquired current into voltage using an LEM Hall current sensor is shown below, where V OUT G is the output voltage value of the Hall sensor, G is the current-to-voltage conversion ratio with a conversion value of 3.3 (mV / A), and Vc is the power supply voltage of the Hall sensor, 5VDC.

[0043]

[0044] Photovoltaic current acquisition circuit, such as Figure 3As shown, the photovoltaic current is acquired by connecting an external LEM Hall current sensor to the terminal. Two sampling resistors R3 and R4 are connected in series at the two output voltage signal ports of the Hall sensor to form a photocurrent acquisition circuit. A current limiting resistor R4 with a resistance of 1K is connected in series and two 1uF capacitors are connected in parallel for filtering. The microprocessor acquires the output voltage of the Hall sensor through the on-chip ADC and calculates the photovoltaic power generation current value.

[0045]

[0046] In the formula, U is the voltage value acquired by the microprocessor, R3 and R4 are sampling resistors with a resistance of 1KΩ, and V OUT Hall sensor output voltage value

[0047] Preferably, the circuit diagram of the photovoltaic AC voltage acquisition circuit is as follows: Figure 4 As shown, sampling resistors R1 and R2 are connected in series to form a voltage acquisition circuit, which is powered by the photovoltaic power generation terminal. The microprocessor module calculates the photovoltaic power generation voltage by acquiring the voltage across R1. To ensure that the voltage acquired by the microprocessor is less than 3.3V, a 1K current-limiting resistor R3 is connected in series with R1, and an operational amplifier TP321-TR is connected in series to provide impedance matching and stabilize the voltage signal transmission.

[0048]

[0049] Where U is the input voltage value collected by the microprocessor, R1 and R2 are sampling resistors, R1 has a resistance of 1KΩ and is grounded, R2 has a resistance of 20KΩ and is divided by R1, and SolarVCC is the actual voltage value at the photovoltaic power generation end.

[0050] The TP321-TR is a high-performance operational amplifier that plays a crucial role in impedance matching within circuits. It effectively balances the impedance differences between the signal source and the load, ensuring smoother signal transmission from the source to the load and preventing signal reflection, distortion, or power loss caused by impedance mismatch. By optimizing impedance matching, the TP321-TR not only improves signal transmission efficiency but also enhances signal stability and integrity, ensuring reliable operation in various applications.

[0051] Preferably, the RN8302B three-phase energy metering chip is selected from Ruineng Microelectronics. The RN8302B minimum system mainly consists of three parts: the main control chip, the decoupling circuit, and the crystal oscillator circuit. Its minimum system circuit is as follows: Figure 5As shown. The three-phase metering chip uses a 3.3V power supply. A low-level PM pin enables the chip to enter metering mode upon power-up. It uses a passive crystal oscillator to amplify the clock signal; the crystal frequency is 8.192MHz, input through the XO and XI pins. Simultaneously, the acquired data is transmitted to the microprocessor via the SPI communication protocol. Load current and voltage signals are differentially input through the IP and IN pins. The crystal oscillator circuit uses a 10MΩ resistor in parallel with two capacitors to form a load capacitance matching network, optimizing the crystal oscillator's startup and stable operation. The decoupling circuit, composed of multiple capacitors distributed between the power supply and ground, effectively filters high-frequency noise on the power line. The decoupling circuit improves the circuit's anti-interference capability, ensures the accuracy of energy metering, and provides a stable power environment for the RN8302B.

[0052] Preferably, the voltage transformer mentioned above is a ZMPT107-1 current-type voltage transformer. The ZMPT107-1 voltage transformer has high insulation performance and can operate stably in high-voltage environments. It converts the high voltage of the power grid into a low-voltage signal through a precise transformation ratio for subsequent circuit processing. Combined with the resistor divider and filter circuits in the acquisition circuit, the ZMPT107-1 voltage transformer can effectively filter out high-frequency noise and interference in the power grid, ensuring the purity of the acquired voltage signal and providing accurate voltage data for the photovoltaic distribution network load rapid and seamless switching device.

[0053] The voltage transformer has a rated input current of 2mA. To ensure that the current transformer's input current does not exceed its rated current, a series of precision voltage divider resistors with a total resistance of 220KΩ are connected in series at the input terminal of the voltage acquisition circuit. When the load is connected to 220V / 50Hz AC mains power, the voltage transformer's input current does not exceed 2mA. The ZMPT107-1 voltage transformer has an output current ratio of 2mA:2mA. Two sampling resistors, R5 and R6, are connected in series to form a voltage acquisition circuit. The three-phase metering chip acquires the voltage value across the sampling resistors. The load voltage acquisition circuit is as follows: Figure 6 As shown.

[0054]

[0055] In the formula V C1 The voltage value is collected by the three-phase power metering chip. R5 and R6 are sampling resistors with a resistance of 50Ω. The rated output current value of I depends on the input current value of the voltage transformer.

[0056] Preferably, the aforementioned current transformer is an HCT226JY-2 current transformer. The HCT226JY-2 current transformer is a high-performance current sensing element widely used in power metering and current monitoring. This transformer provides electrical isolation, ensuring safe isolation of the measurement circuit from the high-voltage, high-current power grid, reducing the impact of electromagnetic interference. Its high accuracy and stability are matched with the RN8302B chip, enabling real-time monitoring and accurate calculation of the load current, thus improving the measurement accuracy and reliability of the switching device.

[0057] The HCT226JY-2 current transformer has a rated input current of 5A and a rated output current of 2.5mA, with an input-output ratio of 2000:1. The load current acquisition circuit connects to the load current via terminals, and two sampling resistors R7 and R8 are connected in series to form a current acquisition loop. The three-phase metering chip acquires the voltage across the sampling resistors to derive and calculate the load operating current value.

[0058]

[0059] In the above formula, U is the voltage value acquired by the three-phase energy metering chip, R7 and R8 are 10Ω sampling resistors, and the output current I depends on the input current value of the current transformer and the ratio of the output current to the input current. The load current acquisition circuit is as follows: Figure 7 As shown.

[0060] Preferably, the aforementioned magnetic latching relay uses a K88E high-power 120A magnetic latching relay. This relay, with its low power consumption and high current carrying capacity, is suitable for high-current scenarios in photovoltaic power distribution networks. The K88E magnetic latching relay can achieve rapid response under pulse signal control, while maintaining the contact state until the next signal arrives, helping to reduce energy consumption and improve the efficiency of the switching device system. The magnetic latching relay drive circuit uses two SH8023 bidirectional magnetic latching relay integrated circuits as drivers to control the K88E magnetic latching relay. A 12VDC power supply is provided to the SH8023 drive circuit. The normally open and normally closed contacts of the magnetic latching relay are led out through connectors to connect the relay coil terminal to the driver output terminal. The microprocessor module inputs signals to the drive circuit to control the opening and closing state of the magnetic latching relay. The magnetic latching relay drive circuit is as follows: Figure 8 As shown.

[0061] Preferably, the aforementioned thyristor module uses the BTA100-1600B high-performance three-terminal bidirectional thyristor. The BTA100-1600B three-terminal bidirectional thyristor has a repetitive peak turn-off voltage and reverse voltage of 1600VAC, and can withstand an effective on-state current of up to 100A and a surge on-state current of 1100A. The maximum current of the photovoltaic power grid load switching device is 100A, and this bidirectional thyristor meets the high-power requirements of the device. The BTA100 three-terminal bidirectional thyristor has a turn-on speed of 100A / µs, meeting the requirements of the switching device for seamless and rapid switching response, and helping to reduce current surges and voltage overshoots during the switching process.

[0062] like Figure 9 As shown, the microprocessor controls the on / off state of the composite switch by sending high and low level signals. An NPN transistor is used to form a level conversion circuit to realize the level conversion between the microprocessor and the composite switch. When the microprocessor's control pin outputs a low level, the transistor conducts, and the 12VDC power supply pulls up the voltage through the pull-up resistor to provide a high-level signal to the composite switch to control its conduction state. Conversely, when the control pin outputs a high level, the level conversion circuit provides a low-level control signal to the composite switch. In addition, the level conversion circuit also provides electrical isolation between the microprocessor and the composite switch.

[0063] The three-phase composite switch circuit consists of a bidirectional optocoupler MOC3051SM, a magnetic latching relay, a thyristor, and a bidirectional optocoupler PCB81A4. The microcontroller outputs control signals through a level conversion circuit, and the bidirectional optocoupler MOC3051 responds to these external control signals. When the microcontroller pin outputs a high-level signal, the bidirectional optocoupler MOC3051SM conducts, supplying power to the switch circuit from the photovoltaic or grid end. This conducts the thyristor, which then opens the magnetic latching relay module, enabling the power supply to the load. The bidirectional optocoupler PCB81A4 in the composite switch circuit conducts when there is current in the circuit. Pin 4 of the optocoupler is connected to a pull-up resistor R. 44 The function of the optocoupler is to output a high level to the microcontroller. When the circuit is broken and there is no current, the optocoupler disconnects, and pin 4 of the optocoupler outputs a low level to the microcontroller. The microcontroller determines whether the switching action is complete based on the received high and low levels. The circuit diagram of the composite switch is shown below. Figure 10 As shown.

[0064] Preferably, to meet the requirements of remote wireless photovoltaic distribution network load switching, the switching device uses the ATK-M751C 4G DTU module from Youren IoT Co., Ltd. to communicate with the data management platform. This module has strong compatibility, can handle large amounts of communication data, and also features low latency, fast transmission speed, no need for additional software support, and permanent online capability. It can not only realize remote data monitoring of the IoT cloud platform, but also achieve functions such as DTU offline alarm, remote configuration of DTU parameters, remote control of the monitoring device, and tracking of DTU location.

[0065] When the microprocessor sends data to the 4G DTU module via the serial port, level conversion is required. The switching device uses the RSM485PHT, an isolated RS485 module with automatic transmit / receive functionality. This module has high electromagnetic interference immunity and very low electromagnetic radiation. In the RS485 communication circuit, a matching resistor is connected in series at the A / B terminals for impedance matching, ensuring that the impedance values ​​at A and B are equal, thereby reducing signal reflection. Twisted-pair cable is used for data transmission, and the shielding layer of the same network is grounded at a single point to ensure reliable data transmission. The RS485 communication circuit schematic is shown below. Figure 11 As shown.

[0066] A stable power supply is a prerequisite for the normal operation of the switching device. The photovoltaic distribution network load switching device is powered by 220V / 50Hz AC mains power. In the power grid environment, electronic equipment faces various challenges. Prolonged exposure to electrostatic discharge, lightning strikes, and strong electromagnetic interference can lead to equipment damage, malfunction, or even endanger power grid safety. Electromagnetic interference includes both external interference and internal interference within the switching device. Therefore, when designing the power module, in addition to improving the switching device's anti-interference capability, its electromagnetic compatibility performance also needs to be optimized to ensure the switching device has good reliability in the power grid environment.

[0067] The microprocessor and external devices require voltages of 12V, 5V, and 3.3V. The switching device uses an EI48X30-15VA transformer module to convert 220VAC to 12VAC. This transformer module has an output power of 20W, meeting the requirements of the switching device, and features small size, high efficiency, low ripple, and dust and water resistance. A KBP310 rectifier bridge is used to convert 12VAC to 12VDC. The KBP310 rectifier bridge provides high-efficiency and high-reliability rectification performance with its 1000V reverse withstand voltage, 3A stable DC output, low forward voltage drop of 1V, and high transient inrush current withstand capability of up to 60A. Its wide operating temperature range and UL94V-0 flame-retardant packaging make it suitable for various harsh environments, making it an ideal choice for power conversion and circuit rectification. The 220VAC to 12VDC circuit diagram is shown below. Figure 14 As shown.

[0068] At the moment of power-on, a large inrush current is generated at the power input terminal because the voltage across capacitor C21 cannot change suddenly. To suppress this inrush current, a fuse F1 and a positive temperature coefficient thermistor R59 are connected in series at the power module input terminal. F1 melts quickly when the inrush current is too large, thus protecting other components from damage caused by the large current. The thermistor's resistance is low at the moment of power-on, which can limit the inrush current and slow down the rate of voltage change, thereby reducing the amplitude of the inrush current. A huge surge voltage is also generated at the moment of power-on, so a varistor R58 is connected in parallel at the circuit input terminal. When there is an overvoltage at the input terminal, the resistance of the varistor will decrease, thus limiting the conduction of the overvoltage. In addition to suppressing surge voltage, the varistor can also limit overvoltages generated by electrostatic discharge, electromagnetic interference, etc. To suppress interference in the circuit, capacitors X and Y are connected in parallel at the power input terminal to suppress high-frequency common-mode interference and low-frequency differential-mode interference, respectively. By connecting a common-mode inductor to the input terminal of the power module, external electromagnetic interference and electromagnetic interference emitted by the monitoring device itself can be suppressed, resulting in a stable 12V voltage to power the photovoltaic load power acquisition module, three-phase composite switch module, and human-machine interaction module of the photovoltaic distribution network device.

[0069] The switching device uses the XL1509-5.0E1 chip to step down 12VDC to 5VDC. The XL1509-5.0E1 is a high-efficiency step-down DC-DC power supply chip with a wide input voltage range of 4.5V to 40V, capable of stably outputting 5V and supporting a maximum output current of 2A. It employs a fixed switching frequency of 150kHz, is packaged in an SOIC-8 package, has a quiescent current of only 150uA, and a wide operating temperature range from -40℃ to +85℃, making it suitable for various power conversion applications. Its excellent performance and reliability meet stringent power management requirements. The 12VDC to 5VDC circuit diagram is shown below. Figure 12 As shown.

[0070] The microprocessor requires a 3.3V power supply for normal operation. An AMS1117-3.3V low-dropout regulator chip is used to convert 5V to 3.3V. The AMS1117-3.3V supports up to 1A of output current and features low quiescent current, excellent ripple suppression, and built-in overcurrent and overheat protection, ensuring power supply stability and reliability. A tantalum capacitor connected in parallel at the output effectively suppresses ripple. The 5VDC to 3.3VDC circuit diagram is shown below. Figure 13 As shown.

[0071] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A seamless, rapid switching device, characterized in that, Includes an STM32 microprocessor, an RN8302B three-phase power metering chip, a power supply module, a photovoltaic power monitoring module, a load power monitoring module, a three-phase composite switch module, a human-machine interaction module, a 4G communication module, and a TF card storage module; The photovoltaic power monitoring module includes a photovoltaic AC voltage acquisition circuit, an on-chip ADC, a photovoltaic AC current acquisition circuit, and a feedthrough current transformer; the STM32 microprocessor uses the feedthrough current transformer to acquire the current signal of the photovoltaic AC current acquisition circuit and uses the on-chip ADC to acquire the voltage signal of the photovoltaic AC voltage acquisition circuit. The load-side power monitoring module includes a load AC voltage acquisition circuit, a voltage transformer, a current transformer, and a load AC current acquisition circuit. The STM32 microprocessor reads the power signal from the load-side power monitoring module transmitted by the RN8302B three-phase power metering chip. The RN8302B three-phase power metering chip is used to acquire the output signal of the load-side power monitoring circuit, acquire the load voltage signal from the load AC voltage acquisition circuit through a voltage transformer, acquire the load current signal from the load AC current acquisition circuit through a current transformer, and send the load power signal to the STM32 microprocessor via the SPI communication protocol. The three-phase composite switch module includes a photovoltaic three-phase switch circuit, a grid three-phase switch circuit, a bidirectional optocoupler MOC3051SM, a magnetic latching relay, a thyristor module, a bidirectional optocoupler PCB81A4, and a level conversion circuit. The STM32 microprocessor outputs a control signal through the level conversion circuit. When the STM32 microprocessor pin outputs a high-level signal, the bidirectional optocoupler MOC3061 is turned on, and either the photovoltaic three-phase switch circuit or the grid three-phase switch circuit supplies power to the switch circuit. The thyristor module is then turned on, and the magnetic latching relay module is turned on, enabling the power supply end to supply power to the load. The function of the bidirectional optocoupler PCB81A4 is to turn on the optocoupler PCB81A4 when there is current in the circuit, and the optocoupler PCB81A4 outputs a high level to the STM32 microprocessor. When the circuit is open and there is no current, the optocoupler is turned off, and the optocoupler PCB81A4 outputs a low level to the STM32 microprocessor. The STM32 microprocessor determines whether the switching action is completed based on the received high and low levels. The STM32 microprocessor wirelessly transmits USART interface data to the background display via the 4G communication module, and interacts with the human-machine interaction module; it also saves important data in the TF card storage module via the SDIO interface, so that the data will not be lost after power failure. The power supply module includes a BUCK circuit, an LDO circuit, and an AC / DC circuit, which provide power to all of the above modules.

2. The seamless, rapid switching device according to claim 1, characterized in that, The photovoltaic AC current acquisition circuit uses a LEM DHAB S / 15 type through-hole Hall sensor to acquire the current value of photovoltaic power generation.

3. The seamless, rapid switching device according to claim 1, characterized in that, The voltage transformer is a ZMPT107-1 current-type voltage transformer.

4. The seamless and rapid switching device according to claim 1, characterized in that, The current transformer used is the HCT226JY-2 current transformer.

5. The seamless and rapid switching device according to claim 1, characterized in that, The magnetic latching relay is a K88E high-power 120A magnetic latching relay.

6. The seamless and rapid switching device according to claim 1, characterized in that, The thyristor module uses the BTA100-1600B high-performance three-terminal bidirectional thyristor.

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