CN219513850U

CN219513850U - Photovoltaic grid-connected switch based on Bluetooth communication

Info

Publication number: CN219513850U
Application number: CN202320815482.0U
Authority: CN
Inventors: 李建
Original assignee: Shenzhen Tengming Technology Co ltd
Current assignee: Shenzhen Tengming Technology Co ltd
Priority date: 2023-04-04
Filing date: 2023-04-04
Publication date: 2023-08-11
Anticipated expiration: 2033-04-04

Abstract

The utility model provides a photovoltaic grid-connected switch based on Bluetooth communication, and belongs to the field of photovoltaic grid-connected switches. The intelligent power supply system comprises a Bluetooth communication circuit, a 485 communication circuit, a liquid crystal display circuit, an electric energy metering circuit, a residual current circuit, a short circuit instantaneous protection circuit, a three-phase current unbalance protection circuit, an MCU data processing circuit and an RTC time real-time clock circuit, wherein the MCU data processing circuit is respectively connected with the Bluetooth communication circuit, the 485 communication channel, the liquid crystal display circuit, the electric energy metering circuit, the residual current circuit, the short circuit instantaneous protection circuit, the three-phase current unbalance protection circuit and the RTC time real-time clock circuit. According to the utility model, the uplink communication interacts with the cloud server in a Bluetooth communication mode, and the downlink communication interacts with the switch sub-equipment in an RS485 mode, so that the intelligent watch searching, file management, data acquisition, data transmission, real-time reporting, event recording, history freezing and other functions are realized; high reliability and convenient installation.

Description

Photovoltaic grid-connected switch based on Bluetooth communication

Technical Field

The utility model provides a photovoltaic grid-connected switch based on Bluetooth communication, and belongs to the field of photovoltaic grid-connected switches.

Background

The information disclosed in the background of the utility model is only for enhancement of understanding of the general background of the utility model and is not necessarily to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Along with the development of the intelligent power grid, the application requirement of the photovoltaic grid-connected switch is also increased, and thus, the requirement is matched with intelligent control. The photovoltaic grid-connected switch is an intelligent collector with edge computing capability, and is matched with intelligent switching equipment (such as a circuit breaker, a measuring switch, a leakage reclosing and other series products) for use; the uplink communication interacts with the cloud server in a Bluetooth communication mode, and the downlink communication interacts with the switch sub-equipment in an RS485 mode, so that the intelligent watch searching, file management, data acquisition, data transmission, real-time reporting, event recording, history freezing and other functions are realized; high reliability and convenient installation.

Disclosure of Invention

According to the photovoltaic grid-connected switch based on Bluetooth communication, the Bluetooth communication mode is used for interacting with the cloud server in uplink communication, the RS485 mode is used for interacting with the switch sub-equipment in downlink communication, and the photovoltaic grid-connected switch based on Bluetooth communication has the functions of intelligent table searching, file management, data acquisition, data transmission, real-time reporting, event recording, history freezing and the like; high reliability and convenient installation.

The utility model provides a photovoltaic grid-connected switch based on Bluetooth communication, which comprises a Bluetooth communication circuit, a 485 communication circuit, a liquid crystal display circuit, an electric energy metering circuit, a residual current circuit, a short-circuit instantaneous protection circuit, a three-phase current unbalance protection circuit, an MCU data processing circuit and an RTC time clock circuit, wherein the MCU data processing circuit is respectively connected with the Bluetooth communication circuit, the 485 communication channel, the liquid crystal display circuit, the electric energy metering circuit, the residual current circuit, the short-circuit instantaneous protection circuit, the three-phase current unbalance protection circuit and the RTC time clock circuit.

The system also comprises an AC inlet surge protection circuit and an AC-DC power supply module, wherein the AC is converted into a double-path DC12V, one path of the DC-DC circuit is converted into a DC-DC circuit of 3.3V, and the other path of the DC-DC circuit is converted into a DC-DC circuit of 5V.

The MCU data processing circuit uses U5 as a main chip to process, the chip adopts 3.3V power supply, and a clock circuit, a reset circuit, a power failure detection circuit and a power supply filter circuit are arranged on the periphery of the chip.

And an isolation chip is arranged in the 485 communication circuit.

The liquid crystal display circuit adopts an LCD display screen and is controlled by connecting an 8-bit parallel data line with the MCU data processing circuit.

The electric energy metering circuit adopts differential sampling metering.

The residual current circuit induces leakage current into a relatively small alternating current through a zero sequence transformer, and the induced alternating current is introduced into a relevant sampling circuit of the circuit board.

The three-phase unbalanced current detection circuit is processed by the principle of zero crossing points.

The Bluetooth communication circuit is a low-power consumption circuit, and the power supply is 3.3V-4.2V.

The utility model has the beneficial effects that:

in the utility model, the uplink communication interacts with the cloud server in a Bluetooth communication mode, and the downlink communication interacts with the switch sub-equipment in an RS485 mode, so that the intelligent watch searching, file management, data acquisition, data transmission, real-time reporting, event recording, history freezing and other functions are realized; high reliability and convenient installation.

Drawings

Fig. 1 is a schematic diagram of a circuit connection structure of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 2 is a schematic diagram of a hardware connection structure of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 3 is a schematic circuit diagram of an MCU circuit of the photovoltaic grid-connected switch based on bluetooth communication.

Fig. 4 is a schematic circuit diagram of an electric quantity metering circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 5 is a schematic circuit diagram of an LCD screen display circuit of the photovoltaic grid-connected switch based on bluetooth communication.

Fig. 6 is a schematic circuit diagram of an electric energy pulse circuit of the photovoltaic grid-connected switch based on bluetooth communication.

Fig. 7 is a schematic circuit diagram of an RS485 communication circuit of the photovoltaic grid-connected switch based on bluetooth communication.

Fig. 8 is a schematic circuit diagram of an infrared control circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 9 is a schematic circuit diagram of a bluetooth module circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 10 is a schematic circuit diagram of an instantaneous short-circuit protection circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 11 is a schematic circuit diagram of a three-phase current imbalance detection circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 12 is a schematic circuit diagram of a voltage metering sampling circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Fig. 13 is a schematic circuit diagram of a current metering sampling circuit of a photovoltaic grid-connected switch based on bluetooth communication.

Detailed Description

The utility model will be further described with reference to the accompanying drawings

According to the utility model, as shown in fig. 1-13, the photovoltaic grid-connected switch based on Bluetooth communication comprises a Bluetooth communication circuit, a 485 communication circuit, a liquid crystal display circuit, an electric energy metering circuit, a residual current circuit, a short-circuit instantaneous protection circuit, a three-phase current unbalance protection circuit, an MCU data processing circuit and an RTC real-time clock circuit, wherein the MCU data processing circuit is respectively connected with the Bluetooth communication circuit, the 485 communication channel, the liquid crystal display circuit, the electric energy metering circuit, the residual current circuit, the short-circuit instantaneous protection circuit, the three-phase current unbalance protection circuit and the RTC real-time clock circuit.

Further detailed description: the power supply supplies power for 220V outside, the power is firstly passed through an AC inlet surge protection circuit, then is converted into two-way 12V power supply through an AC-DC power supply module, and one-way 12V power supply is used for supplying power for MCU, FLASH, E PROM and a Bluetooth communication circuit; one path of 12V DC-DC power is converted into 5V power to supply power for the RS485 chip. Electric isolation treatment is carried out between the two weak current power supplies and 220V strong current, and 2500VAC isolation is carried out between the input and the double output; 2000VAC isolation between the dual outputs 12V and 12V.

The AC inlet surge protection circuit is characterized in that AB C three-phase power is respectively connected with piezoresistors RV1 RV2 RV3. And then the power resistor R1R 2R 3 is connected. After passing through the two devices, the surge incoming quantity can be consumed, so that the surge protection effect is achieved. Then, the rectifying circuit is started, and in the design, the rectifying device adopts a rectifying diode D1D 2D 3D 4D 5D 6D 7D 8 with higher withstand voltage value. After rectification, the power supply enters a switching power supply module to reduce the voltage to two paths of DC12V. Wherein 12V is the power supply to the whole system circuit, including MCU circuit metering chip circuit, memory circuit, temperature sampling circuit, system reset circuit, etc. The other path of DC12V is converted into DC5V circuit to supply power to the two paths of RS485 circuits independently, and the DC12V circuit has an isolation function of 2000V. The 12V-to-3.3V circuit is characterized in that one path of 12V is firstly converted into 5V through a DC-DC chip U4, and then the 5V is converted into 3.3V through an LDO chip U2. The DC-DC chip U4 is an adjustable DC-DC, and the output voltage value can be adjusted through the feedback resistor R7R 8. There are two ceramic capacitors to ground at the power input of U4. Respectively C5 and C6, whose values are respectively 10uf and 0.1uf, which can play the roles of filtering and decoupling, that is, when the power source fluctuates, the two capacitors can play the role of enabling the power source to supply power stably. At the voltage output of U4, there are also two ceramic capacitors C10C 11 to ground, which are also 10uf and 0.1uf, respectively. They can play the role of filtering and decoupling, and ensure that the output voltage is a stable 5V output. After being converted into 5V output, the output is converted into 3.3V through a chip U2. The power input port and the power output port of the chip U3 are respectively provided with two ceramic capacitors for filtering and decoupling the power supply, so that stable input and output of the power supply are ensured.

Further detailed description: the chip has rich interfaces, wherein, the burning interface of the chip is used for program upgrading of the chip. The AD conversion interface of the chip is used for analog signal sampling processing. The power-down detection pin of the chip is used for power-down detection. The reset pin of the chip is used for power-on reset and abnormal condition reset processing. The VBAT pin of this chip is used for real-time RTC recording. An I2C interface is used for connecting E2P devices for storage purposes. The SPI interface of the device is used for connecting a Flash device and storing large-capacity data. The LCD interface of the chip is used for connecting with the LCD display so as to drive the display. Two pairs of UART serial ports are used and connected to the metering chip for communication with the metering chip. A pair of UART interfaces are connected to the RS485 module circuit and are used for communicating with RS 485. The HOSCI interface is used for being connected with a crystal oscillator of a clock circuit so as to provide an oscillating clock for the MCU. While other I/O ports are also used as processing of some control signals. When the MCU is powered on, the address information of the intelligent circuit breaker is acquired through the downlink 485 channel, and the address number of the downlink equipment is judged according to the acquired address. And managing the mounted files according to the intelligent search table, managing the file addition of the newly added equipment, the file removal of the invalid equipment, the data difference inquiry among different equipment and the like. The files are stored in FLASH. The MCU is internally provided with a clock chip, and is used as a counting clock of the RTC through an external low-speed oscillator (32.768 kHz crystal oscillator), and the clock timing is mainly obtained from a master station after the RTC is electrified, so that the normal operation of the RTC after the RTC is electrified is maintained. Meanwhile, after file management is confirmed, bluetooth accurately collects electricity consumption data such as voltage, current, active power, line temperature, leakage current, electric energy and the like of the intelligent switch equipment in real time, waits for inquiring or actively reporting the data, and is beneficial to electric quantity statistics, power grid quality analysis, electricity consumption safety and the like. And the gateway can exchange data with the local protocol in the remote protocol with different communication protocols and data formats so as to achieve the operations of network interconnection, data inquiry, parameter setting, instruction control and the like.

And an isolation chip is arranged in the 485 communication circuit.

Further detailed description: and the isolation chip isolates UART communication between the RS485 channel and the MCU through the isolation chip U13, so that signal electrical isolation can be performed, and performance interference is avoided. The isolation chip is an RS485 communication digital isolation chip, and the withstand voltage reaches 5000kVRMS. The chip integrates the capability of digital isolation and RS485 communication. The URAT-TX URAT-RX URAT-RD of the MCU is directly connected to the front end of the U13 for data transmission and reception.

The RS485 chip is internally provided with an isolation circuit, so that the isolation circuit is not needed, 3.3V of the MCU is connected at VDDA, and 5V power supply drive of RS485 is connected at VDDB. The chip is internally provided with a failure protection function, so that when the input end of the receiver is in an open circuit or short circuit, the chip with the output end of the receiver in a logic high level state uses a slew rate limiting driver, the EMI and the reflection caused by an improper terminal matching cable can be obviously reduced, and the error-free data transmission of up to 500kbps is realized. The input impedance of the transceiver is 1/8 unit load, and 256 transceivers can be hung on the bus at maximum, so that half-duplex communication is realized. The I/O port pin has + -15 kV IEC 61000-4-2 contact discharge protection function. A/B interface of the 485 chip is externally hung with a bidirectional TVS protection device TVS1, the bidirectional TVS of the three-port D1 is integrated through the connection of the A/B interface end to the DGND, and the output end of the A/B interface is connected with PPTC resistors F1 and F2 in series.

Further detailed description: the liquid crystal display circuit directly connects the flat cable of the LCD screen to the FPC pedestal, the data interface is then connected to the MCU through the series resistor R60R 61R 62R 63R 64R 65R 66R 67R 68R 69R 70R 71R 72, and the data transmission of the LCD screen is carried out to control the display of the data on the LCD screen, namely, the acquired current, voltage and information of various events are displayed. In this circuit, the brightness of the LCD backlight is adjustable, and we compose the hardware control part of backlight adjustment through R103, R104, C54, Q3, R102. Has the function of displaying Chinese characters and the function of adjusting backlight brightness.

The electric energy metering circuit adopts differential sampling metering.

Further detailed description: the commercial power current is converted into small current of milliamp level through the metering transformer and is led into the circuit board, and voltage conversion is carried out on the circuit board through a resistor, so that the small current is converted into differential voltage sampling values within the identification range of the metering chip for processing. And the corresponding electric quantity data is uploaded to the client through the Bluetooth communication circuit by processing the metering chip and the MCU chip, so that the client checks the electric quantity. In the sampling circuit, 2 resistors with the resistance of 2 ohms are adopted for differential sampling, and the rear end is respectively connected with a ceramic capacitor with the capacitance of 3.3nF for filtering, so that the alternating current differential voltage can be measured by a measuring chip more stably.

Further refining: the electric energy metering circuit is characterized in that three-phase electricity passes through three transformers respectively, the transformers are connected to sockets of a circuit board respectively, currents induced by the transformers are converted into differential voltages through resistors R133R 134R 137R 138R 141R 142 respectively and then enter a metering chip, the metering chip calculates data, then the data are transmitted to an MCU through a serial port for unified processing, the MCU transmits the data to a Bluetooth communication circuit through the serial port of the MCU after the data are processed, and the Bluetooth communication circuit transmits the data to a remote client through a wireless transmission protocol, so that a client looks over electric quantity.

Further detailed description: the leakage current sampling circuit performs amplification sampling through a 4.02 ohm resistor, and converts the current into a voltage value. Thus, the MCU is introduced to perform analysis processing, and when the leakage current is judged to be more than 30MA, the MCU performs brake-off processing. After the sampling circuit, a ceramic capacitor with 3.3nF is connected to the ground for filtering, so that a more stable signal enters the MCU chip for processing.

Further detailed description: the photovoltaic grid-connected switch product has an overvoltage protection function, when the circuit monitors that the voltage exceeds the industry standard value, the equipment performs overvoltage treatment, so that the equipment is disconnected and powered down, and no longer works, thereby playing a role in protection. The specific implementation method is that 6 resistors of 200K and 1 resistor of 20K are connected in series to divide voltage, then the voltage of the resistor end of 20K is taken to perform AD conversion, and an analog signal is converted into a digital signal. And the MCU judges the converted digital signals. After the number exceeds the threshold value set by us, the MCU sends an instruction to enable the equipment to be switched off and cut off, so that the protection effect is achieved.

Further detailed description: when the current outgoing lines of the three-phase power supply are unbalanced, the three-phase unbalanced current protection circuit can generate a signal change, the signal change is transmitted to the MCU, the MCU is used for judging, then the MCU performs a brake-separating action, and the mains supply is disconnected, so that the protection effect is achieved. Here we access diodes D12R 123, D13R 219, D14R 220 to the AB C three-phase power respectively, then splice the anodes of the leds to the optocoupler, and connect the N-wire to the cathodes of the leds. The collector of the optocoupler is connected to the MCU through a pull-up resistor, so that the MCU obtains the level change of the MCU, and the emitter of the optocoupler is grounded. When the current of the three-phase power is balanced, the current flowing through the light emitting diode of the optocoupler is zero, so that the optocoupler is not conducted, the signal at the collector of the optocoupler is unchanged and always at a high level, and the MCU is always detected as a high level, so that the MCU judges that the three-phase current is balanced and the switching-off process is not performed. If the current flowing through the light emitting diode of the optocoupler is not zero when the current of the three-phase power is unbalanced, the light emitting diode emits light, the optocoupler is conducted, and the level at the collector electrode of the optocoupler is changed from a high level to a low level. At this time, the MCU will detect that the level is changed from high level to low level, so that the MCU judges that the current of the three-phase power is unbalanced, and the MCU will send an instruction to control the equipment to break the gate and break the power, thereby achieving the protection effect.

Further detailed description: when the current of the accessed mains supply is very large instantaneously, the equipment detects abnormality, judges that the equipment is short-circuited, and performs switching-off and power-off treatment, so that the protection effect is achieved. Firstly, three protection transformers are respectively arranged on three-phase current, the currents induced by the transformers are respectively connected to three bridge stacks for rectification, the rectified direct current voltage is distributed to an MCU for processing, firstly, voltage signals are converted into digital values through AD, and then judgment processing is carried out in the MCU. When one of the three-phase power is short-circuited or the multi-phase power is short-circuited at the same time, the MCU judges a short-circuited signal and gives the short-circuited signal to the equipment for switching off, so that the function of power-off protection is achieved.

Further detailed description: the emission power of the Bluetooth communication circuit is 0dbm, the working current is uA-level product, and in order to ensure that the Bluetooth communication circuit emits the maximum power, the power supply voltage of the Bluetooth communication circuit is at least required to be ensured to work at 3.3V. Meanwhile, at the VCC_BT end of the power supply interface of the Bluetooth communication circuit, two ceramic capacitors C60 and C61 are arranged, so that partial power supply capacity of the ceramic capacitors is ensured to be shared under the condition of insufficient power supply of an instantaneous power supply. Meanwhile, the work of the Bluetooth communication circuit is ensured to be low in interference. The Bluetooth communication circuit and the MCU are in URAT communication, the MCU sends data to the RX pin of the Bluetooth communication circuit through the TX pin of the MUC, so that the capacity of the MCU for controlling the Bluetooth communication circuit is achieved, and after the Bluetooth communication circuit receives the data, the Bluetooth communication circuit sends the data to the RX pin of the MCU module through the TX pin of the Bluetooth communication circuit, so that the data of the Bluetooth communication circuit is transmitted to the MCU for processing. The Bluetooth communication circuit also has software reset control, and is connected with the RST pin of the Bluetooth module through the IO port of the MCU to carry out reset control, and when the Bluetooth communication circuit is required to be reset, an instruction is sent through the MCU.

The utility model and its embodiments have been described in terms of components which are standard components or which are known to those skilled in the art, whose construction and principle are known to those skilled in the art from technical manuals or by routine experimentation, and are not limited to the embodiments shown in the drawings, but are only one of them, without limiting the actual construction. In summary, if one of ordinary skill in the art is informed by this disclosure, a structural manner and an embodiment similar to the technical solution should not be creatively devised without departing from the gist of the present utility model.

Claims

1. Photovoltaic grid-connected switch based on bluetooth communication, its characterized in that: the intelligent power supply system comprises a Bluetooth communication circuit, a 485 communication circuit, a liquid crystal display circuit, an electric energy metering circuit, a residual current circuit, a short circuit instantaneous protection circuit, a three-phase current unbalance protection circuit, an MCU data processing circuit and an RTC time real-time clock circuit, wherein the MCU data processing circuit is respectively connected with the Bluetooth communication circuit, the 485 communication channel, the liquid crystal display circuit, the electric energy metering circuit, the residual current circuit, the short circuit instantaneous protection circuit, the three-phase current unbalance protection circuit and the RTC time real-time clock circuit.

2. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the system also comprises an AC inlet surge protection circuit and an AC-DC power supply module, wherein the AC is converted into a double-path DC12V, one path of the DC-DC circuit is converted into a DC-DC circuit of 3.3V, and the other path of the DC-DC circuit is converted into a DC-DC circuit of 5V.

3. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the MCU data processing circuit uses U5 as a main chip to process, the chip adopts 3.3V power supply, and a clock circuit, a reset circuit, a power failure detection circuit and a power supply filter circuit are arranged on the periphery of the chip.

4. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: and an isolation chip is arranged in the 485 communication circuit.

5. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the liquid crystal display circuit adopts an LCD display screen and is controlled by connecting an 8-bit parallel data line with the MCU data processing circuit.

6. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the electric energy metering circuit adopts differential sampling metering.

7. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the residual current circuit induces leakage current into a relatively small alternating current through a zero sequence transformer, and the induced alternating current is introduced into a relevant sampling circuit of the circuit board.

8. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the three-phase unbalanced current detection circuit is processed by the principle of zero crossing points.

9. The bluetooth communication based photovoltaic grid-connected switch according to claim 1, wherein: the Bluetooth communication circuit is a low-power consumption circuit, and the power supply is 3.3V-4.2V.