AC / DC power supply monitoring module

Abstract

The utility model relates to the field of electric energy monitoring and management, in particular to an AC / DC power supply monitoring module, which comprises a single-chip microcomputer minimum system used for judging the abnormal condition of a power supply to be detected, controlling the on-off of the power supply of an electric device, and communicating with an external main control unit, an over-voltage protection value, an under-voltage protection value and an over-current protection value are set, on-off of power output is controlled, a query instruction can be received, and data such as voltage, current, power and frequency can be returned according to needs; the output control circuit is used for completing an output on-off control function of the power supply to be tested; the alternating current and direct current electric energy sampling circuit is used for collecting a to-be-tested power supply in real time; the R485 communication circuit is used for communication between the single-chip microcomputer and an external main control unit; and the other interface circuits are used for being connected with other main control modules. The monitoring function of the to-be-tested power supply and the on-off control function of the output of the to-be-tested power supply are realized, and the on-off control function comprises the control of output power supply overvoltage protection, under-voltage protection, over-current protection, host instruction on-off switching and the like.

Description

Technical Field

[0001] The utility model relates to the field of electric energy monitoring and management, in particular to an AC / DC power supply monitoring module. Background Art

[0002] With the development of power systems, the demand for monitoring and management of electric energy is increasing. Traditional methods of monitoring electric energy mainly rely on manual meter reading, which is cumbersome, inefficient and error-prone. With the development of electronic technology, automated meter reading equipment has gradually been applied to power systems, improving meter reading efficiency, but it still cannot meet the needs of large-scale power grids. At present, electric energy monitoring and management technology has made certain progress. The widespread application of smart meters has improved the accuracy and real-time nature of electric energy data collection. Smart meters can realize automatic meter reading and remote transmission of electric energy data, reducing manual intervention and errors. However, smart meters cannot play a management role, so it is necessary to develop more advanced and reliable electric energy monitoring and management technologies. Utility Model Content

[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide an AC / DC power supply monitoring module.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] The utility model provides an AC / DC power supply monitoring module, comprising: an AC / DC power sampling circuit, a single-chip microcomputer minimum system, an output control circuit, a communication circuit and other interface circuits, wherein a first input end of the AC / DC power sampling circuit is connected to a voltage output to be measured, a second input end is connected to a DC power supply input, an output end of the AC / DC power sampling circuit is connected to the output control circuit, the AC / DC power sampling circuit is connected to the single-chip microcomputer minimum system, the single-chip microcomputer minimum system is respectively connected to the other interface circuits and the communication circuit, an input end of the single-chip microcomputer minimum system is connected to a DC power supply input, an output end of the single-chip microcomputer minimum system is connected to the output control circuit, an output end of the output control circuit is connected to a voltage output to be measured, and an input end of the communication circuit is connected to a DC power supply input.

[0006] Furthermore, the AC / DC power sampling circuit includes: an AC / DC power sampling unit, an isolated power supply unit and a communication isolation unit, the AC / DC power sampling unit is connected to the communication isolation unit, and the isolated power supply unit is arranged between the AC / DC power sampling unit and the communication isolation unit.

[0007] Preferably, the AC / DC power sampling unit is composed of a power collection chip, a crystal oscillator, a current sampling circuit, and a voltage sampling circuit. The current sampling circuit is connected to a first input pin of the power collection chip, the voltage sampling circuit is connected to a second input pin of the power collection chip, the crystal oscillator is connected to a clock pin of the power collection chip, and the isolated power supply unit is arranged on the power collection chip.

[0008] Furthermore, the communication circuit includes a driving unit, an isolated power supply unit and a communication isolation unit, the communication isolation unit is connected to the driving unit, and the isolated power supply unit is arranged between the driving unit and the communication isolation unit.

[0009] Preferably, the driving part is composed of a level driving chip, an impedance matching circuit, an anti-surge circuit and a filtering circuit, the communication isolation unit is connected to the level driving chip, the isolation power supply unit is arranged on the level driving chip, and the level driving chip is respectively connected to the impedance matching circuit, the anti-surge circuit and the filtering circuit.

[0010] Preferably, the surge protection circuit is composed of three bidirectional TVS transient suppression diodes DR1, DR2 and DR3 connected in series.

[0011] Furthermore, the single-chip microcomputer minimum system is composed of a single-chip microcomputer and a filter circuit.

[0012] Furthermore, the remaining interface circuits include two ADC acquisition interfaces, an SPI bus interface and an IIC bus interface.

[0013] Preferably, the ADC acquisition interface is composed of a 10-bit A / D converter and two voltage-dividing resistors inside the single-chip microcomputer, the SPI bus interface is composed of SPI high-speed serial communication and pull-up resistors integrated inside the single-chip microcomputer, and the IIC bus interface is composed of IIC high-speed serial communication and pull-up resistors integrated inside the single-chip microcomputer.

[0014] Furthermore, the output control circuit is composed of a relay, a driving transistor and an output indicator light, and the driving transistor and the output indicator light are connected in parallel to the relay.

[0015] The beneficial effects of the utility model are:

[0016] 1) The utility model collects data of the power supply to be tested in real time by setting up an AC and DC power sampling circuit. The single-chip microcomputer periodically reads the data collected by the power sampling circuit, processes and stores the data, thereby realizing real-time monitoring of the performance parameters of the power supply to be tested, such as voltage, current, power, frequency (AC only), etc.

[0017] 2) The utility model is provided with a single-chip microcomputer system to complete the output on-off control function of the power supply under test, including output power overvoltage protection, undervoltage protection, overcurrent protection and host command on-off switching control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a principle block diagram of an AC / DC power supply monitoring module in an embodiment of the present utility model;

[0019] Figure 2 It is a schematic diagram of an AC / DC power sampling circuit of an AC / DC power supply monitoring module in an embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of an output control circuit of an AC / DC power supply monitoring module in an embodiment of the utility model;

[0021] Figure 4 This is a schematic diagram of an RS485 communication circuit of an AC / DC power supply monitoring module in an embodiment of the present utility model;

[0022] Figure 5 The following is a schematic diagram of the remaining interface circuits of an AC / DC power supply monitoring module in an embodiment of the utility model. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0024] For example, Figure 1As shown, the utility model provides an AC / DC power supply monitoring module, including: an AC / DC power sampling circuit, a single-chip microcomputer minimum system, an output control circuit, an RS485 communication circuit and other interface circuits, the first input end of the AC / DC power sampling circuit is connected to the voltage output to be measured, the second input end is connected to the DC power supply input, the output end of the AC / DC power sampling circuit is connected to the output control circuit, the AC / DC power sampling circuit is connected to the single-chip microcomputer minimum system, the single-chip microcomputer minimum system is respectively connected to the other interface circuits and the RS485 communication circuit, the input end of the single-chip microcomputer minimum system is connected to the DC power supply input, the output end of the single-chip microcomputer minimum system is connected to the output control circuit, the output end of the output control circuit is connected to the voltage output to be measured, the input end of the RS485 communication circuit is connected to the DC power supply input, the RS485 communication circuit is connected to other main control modules, and the other interface circuits are connected to the main control module. The AC and DC power sampling circuit is used to collect data from the power supply to be tested in real time. The single-chip microcomputer is connected to the AC and DC power sampling circuit, and the data collected by the power sampling circuit is read regularly and processed and stored. At the same time, the single-chip microcomputer also judges the abnormal conditions of the power supply to be tested, such as overvoltage, undervoltage, and overcurrent. When an abnormal situation occurs, the output is automatically disconnected to protect the electrical components. In addition, it is connected to the RS485 communication circuit to communicate with the external main control unit to realize the setting of overvoltage protection value, undervoltage protection value, overcurrent protection value, and program-controlled power supply output on and off. It can also receive query instructions and return voltage, current, power, frequency and other data as needed. The single-chip microcomputer is also connected to other interface circuits to realize the connection with other main control modules.

[0025] For example, Figure 2As shown, the AC / DC power sampling part is used to complete the power sampling function of the AC / DC power supply, and is composed of the RN8207C power acquisition chip, 3.579545MHz crystal oscillator, current sampling circuit, voltage sampling circuit and necessary resistor and capacitor components. The current sampling circuit is that the power to be tested flows through the high-precision low-temperature drift sampling resistor R17 to form a weak voltage difference at both ends of the sampling resistor. This voltage is filtered by the anti-aliasing filter circuit composed of R16, C4, R18 and C9 and sent to the current sampling end of the RN8207C power acquisition chip to complete the current sampling. The voltage sampling circuit is that the power to be tested is divided by the resistors R21, R22, R30, R23 and R25, and a weak voltage difference is formed at both ends of R25. This voltage is filtered by the anti-aliasing filter circuit composed of R25, C12, R28 and C16 and sent to the voltage sampling end of the RN8207C power acquisition chip to complete the voltage sampling. The sampling resistor of the current acquisition channel and the voltage divider resistor of the voltage channel can be selected according to the actual voltage and current values ​​of the power supply to be tested, which can further increase the test accuracy. In addition, to ensure the stability and reliability of the measured data, the resistor and capacitor components of the current sampling channel and the voltage sampling channel should all be low-temperature drift devices. It is used to ensure the electrical isolation of the high-voltage end (power supply to be tested) and the low-voltage end (microcontroller minimum system and RS485 circuit) of the AC and DC power supply monitoring module to avoid high voltage damage to the equipment or personal safety accidents. The isolated power supply circuit is designed to power the RN8207C power acquisition chip and the π121E30S digital isolation chip. It consists of a B0505S-1W isolated power supply module, input filter, output filter, disposable fuse and power indicator light.

[0026] The communication isolation part is mainly used for electrical isolation between the RN8207C power collection chip and the single-chip microcomputer during data communication. The π121E30S digital isolation chip is selected as the main device to isolate the serial port communication between the RN8207C power collection chip and the single-chip microcomputer. The serial port transmitter (TX) of the RN8207C chip is filtered by R19 and C10 and sent to the data input terminal (VIB) of the π121E30S chip. After isolation, the data output terminal (VOB) of the 121E30S chip sends the data to the serial port receiving terminal (RXD2) of the single-chip microcomputer. The serial port transmitter (TXD2) of the single-chip microcomputer sends the data to the data input terminal (VIA) of the π121E30S chip. After isolation, the data output terminal (VOA) of the 121E30S chip sends the data and is filtered by C13 and R24 and sent to the serial port receiving terminal (RX) of the RN8207C chip.

[0027] For example, Figure 3As shown, the output control circuit is mainly used to complete the on-off control function of the power supply to be tested, which includes a relay, a driving transistor and an output indicator light. The driving transistor and the output indicator light are connected in parallel on the relay. When the single-chip microcomputer determines that the power supply to be tested needs to be connected to the output, the program sets the single-chip microcomputer P1-7 pin to a high level. At this time, the transistor Q1 is turned on, the relay is energized, the relay contacts 3 and 5 are connected, the power supply to be tested is connected to the output, and the power output indicator LED1 is lit. When the single-chip microcomputer determines that the power supply to be tested needs to be disconnected from the output, the program sets the single-chip microcomputer P1-7 contact to a low level. At this time, the transistor Q1 is cut off, the relay is disconnected, the relay contacts 3 and 5 are disconnected, the output of the power supply to be tested is disconnected, and the power output indicator LED1 is off.

[0028] For example, Figure 4 As shown, the RS485 driver part is mainly composed of the MAX485 level driver chip as the core, with impedance matching circuit, surge protection circuit and necessary filtering circuit. The MAX485 level driver chip is a special RS485 communication driver chip with a communication speed of up to 2.5Mbps. The serial port communication baud rate designed by the utility model is 115200bps, and the MAX485 chip meets the communication requirements of the utility model. In order to prevent the module from being damaged by the surge voltage generated on the RS485 bus due to unexpected situations such as lightning strikes, user wiring errors or hot plugging, the RS485 driver part is specially designed with a surge protection circuit, which is mainly composed of three bidirectional TVS transient suppression diodes DR1, DR2 and DR3, which are used to absorb the peak pulses on the bus to protect the module. In order to ensure the safety of equipment and improve the reliability of RS485 communication, a DC-DC isolation power supply circuit is designed to power the MAX485 chip and the π131E30S digital isolation chip. It consists of a B0505S-1W isolation power supply module, input filter, output filter, disposable fuse and power indicator light. The communication isolation part is mainly to achieve electrical isolation when the MAX485 chip and the single-chip microcomputer communicate data. The π131E30S digital isolation chip is selected as the main device to isolate the serial port communication between the MAX485 chip and the single-chip microcomputer to protect the safety of the equipment.

[0029] For example, Figure 5As shown, the remaining interface circuits are mainly reserved interfaces of this module, mainly including two ADC acquisition interfaces, SPI bus interface and IIC bus interface. The ADC acquisition interface is based on the 10-bit A / D converter inside the STC8G1K08 microcontroller, and is composed of two voltage-dividing resistors. By selecting the voltage-dividing resistor value, the voltage test range can be expanded; the SPI bus interface is based on the SPI high-speed serial communication integrated inside the STC8G1K08 microcontroller, and is composed of pull-up resistors, and three chip select ports are reserved, which can communicate with three communication units at the same time by SPI bus; the IIC bus interface is based on the IIC high-speed serial communication integrated inside the STC8G1K08 microcontroller, and is composed of pull-up resistors. The SPI bus and IIC bus are only suitable for short-distance communication. They are used to expand the functional interface of this module, and the main communication method is RS485 communication.

[0030] Exemplarily, the single-chip microcomputer minimum system uses STC's STC8G1K08 single-chip microcomputer as the core, and is composed of peripheral filtering circuits. The STC8G series single-chip microcomputer is a new generation of 8051 single-chip microcomputers with wide voltage, high speed, high reliability, low power consumption, strong anti-static and strong anti-interference. It does not require an external crystal oscillator and an external reset circuit, which greatly simplifies the hardware design and has a rich peripheral interface, which fully meets the functional requirements of this power monitoring module. This power module is designed as an independent PCB board with an external size of 50mm*100mm. The input and output interface of the power supply to be tested uses a screw terminal with a spacing of 5.08mm, the RS485 communication interface uses a 3.81mm screw terminal, and the remaining interfaces use 2.54mm plug-in terminals.

[0031] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. An AC / DC power supply monitoring module, characterized in that: include: AC / DC power sampling circuit, single-chip minimum system, output control circuit, communication circuit and other interface circuits, the first input end of the AC / DC power sampling circuit is connected to the voltage output to be measured, the second input end is connected to the DC power supply input, the output end of the AC / DC power sampling circuit is connected to the output control circuit, the AC / DC power sampling circuit is connected to the single-chip minimum system, the single-chip minimum system is respectively connected to the other interface circuits and the communication circuit, the input end of the single-chip minimum system is connected to the DC power supply input, the output end of the single-chip minimum system is connected to the output control circuit, the output end of the output control circuit is connected to the voltage output to be measured, and the input end of the communication circuit is connected to the DC power supply input.

2. The AC / DC power supply monitoring module according to claim 1, characterized in that: The AC / DC power sampling circuit includes: an AC / DC power sampling unit, an isolated power supply unit and a communication isolation unit. The AC / DC power sampling unit is connected to the communication isolation unit, and the isolated power supply unit is arranged between the AC / DC power sampling unit and the communication isolation unit.

3. An AC / DC power supply monitoring module according to claim 2, characterized in that: The AC / DC power sampling unit is composed of a power collection chip, a crystal oscillator, a current sampling circuit, and a voltage sampling circuit. The current sampling circuit is connected to a first input pin of the power collection chip, the voltage sampling circuit is connected to a second input pin of the power collection chip, the crystal oscillator is connected to a clock pin of the power collection chip, and the isolated power supply unit is arranged on the power collection chip.

4. The AC / DC power supply monitoring module according to claim 1, characterized in that: The communication circuit includes a driving unit, an isolated power supply unit and a communication isolation unit. The communication isolation unit is connected to the driving unit, and the isolated power supply unit is arranged between the driving unit and the communication isolation unit.

5. The AC / DC power supply monitoring module according to claim 4, characterized in that: The driving part is composed of a driving chip, an impedance matching circuit, an anti-surge circuit and a filtering circuit. The communication isolation unit is connected to the driving chip. The isolated power supply unit is arranged on the driving chip. The driving chip is connected to the impedance matching circuit, the anti-surge circuit and the filtering circuit respectively.

6. The AC / DC power supply monitoring module according to claim 5, characterized in that: The surge protection circuit is composed of three bidirectional TVS transient suppression diodes DR1, DR2 and DR3 connected in series.

7. The AC / DC power supply monitoring module according to claim 1, characterized in that: The single-chip computer minimum system is composed of a single-chip computer and a filter circuit.

8. The AC / DC power supply monitoring module according to claim 1, characterized in that: The remaining interface circuits include two ADC acquisition interfaces, an SPI bus interface and an IIC bus interface.

9. The AC / DC power supply monitoring module according to claim 8, characterized in that: The ADC acquisition interface is composed of a 10-bit A / D converter and two voltage-dividing resistors inside the single-chip microcomputer, the SPI bus interface is composed of SPI high-speed serial communication and pull-up resistors integrated inside the single-chip microcomputer, and the IIC bus interface is composed of IIC high-speed serial communication and pull-up resistors integrated inside the single-chip microcomputer.

10. The AC / DC power supply monitoring module according to claim 1, characterized in that: The output control circuit is composed of a relay, a driving transistor and an output indicator light, and the driving transistor and the output indicator light are connected in parallel to the relay.

Images