Data acquisition circuit for line multi-terminal differential protection device

Abstract

The utility model discloses a data acquisition circuit used for a line multi-terminal differential protection device. The data acquisition circuit comprises a power supply module, a signal acquisition module, a control module, a communication module, a digital-to-analog conversion module, a digital-to-analog isolation module, a time acquisition module, an alarm module and a storage module. The power module supplies power; the signal acquisition module acquires and uploads data information; the communication module is used for external communication; the digital-to-analog conversion module is used for converting the received digital signal into an analog signal and outputting the analog signal; the digital-analog isolation module is used for data isolation; the time acquisition module acquires time information and uploads the time information; the alarm module gives an alarm; the storage module stores data information; the control module controls the circuit to work. According to the utility model, the time acquisition module is additionally arranged in the circuit, and the corresponding data acquisition circuit is arranged, so that data acquisition of the line multi-terminal differential protection device is realized, time information can be provided, and the circuit is higher in reliability and better in accuracy.

Description

Technical Field

[0001] This utility model belongs to the field of electrical automation, specifically relating to a data acquisition circuit for a multi-terminal differential protection device for lines. Background Technology

[0002] With economic and technological development and the improvement of people's living standards, electricity has become an indispensable secondary energy source in people's production and daily life, bringing endless convenience. Therefore, ensuring a stable and reliable supply of electricity has become one of the most important tasks of the power system.

[0003] Multi-terminal differential protection for power systems is a key power protection technology, and its reliability is crucial for maintaining the stable operation of the power system. Therefore, multi-terminal differential protection devices play an important role and are of great significance for the safe and stable operation of the power system.

[0004] When operating, multi-terminal differential protection devices for power lines require real-time acquisition of multi-terminal data from the power system. However, existing data acquisition circuits, such as the data acquisition system with application number 201620106051.7 or application number 201921598986.1, cannot directly record the time information during data acquisition. This means that existing data acquisition systems cannot provide time information during the multi-terminal differential protection process, severely impacting the implementation of multi-terminal differential protection and the operation of the multi-terminal differential protection device. Utility Model Content

[0005] The purpose of this invention is to provide a data acquisition circuit for a multi-terminal differential protection device of a line that can provide time information and has high reliability and accuracy.

[0006] The data acquisition circuit for a multi-terminal differential protection device for power lines provided by this invention includes a power supply module, a signal acquisition module, a control module, a communication module, a digital-to-analog conversion module, a digital-to-analog isolation module, a time acquisition module, an alarm module, and a storage module. The signal acquisition module, communication module, digital-to-analog isolation module, time acquisition module, alarm module, and storage module are all connected to the control module. The digital-to-analog conversion module is connected to the digital-to-analog isolation module. The power supply module supplies power to the data acquisition circuit. The signal acquisition module acquires the data information required by the multi-terminal differential protection device for power lines and uploads it to the control module. The communication module enables communication between the data acquisition circuit and external systems. The digital-to-analog conversion module receives digital signals from the digital-to-analog isolation module and converts them into analog signals for external output. The digital-to-analog isolation module receives digital signals from the control module, isolates the data, and outputs it to the digital-to-analog conversion module. The time acquisition module acquires time information and uploads it to the control module. The alarm module receives control signals from the control module and triggers an alarm. The storage module stores the data information of the data acquisition circuit. The control module controls the operation of the data acquisition circuit.

[0007] The signal acquisition module includes a voltage signal acquisition circuit and a current signal acquisition circuit; the voltage signal acquisition circuit is used to acquire the voltage signal of the power system, and the current signal acquisition circuit is used to acquire the current signal of the power system.

[0008] The control module is a circuit consisting of a control module of model Z7-204P-CORE.

[0009] The communication module is a circuit consisting of a communication module of model ME3630.

[0010] The digital-to-analog converter module is a circuit composed of a DAC7734EC digital-to-analog converter chip.

[0011] The digital-to-analog isolation module is a circuit composed of an isolation chip of model ISO7240CF.

[0012] The time acquisition module is a circuit composed of a timing chip of model LEA-6T.

[0013] The alarm module is a circuit consisting of a MOSFET and a buzzer.

[0014] The storage module is a circuit composed of storage chips with the model number W25Q256JVEIQ.

[0015] The data acquisition circuit for multi-terminal differential protection devices provided by this utility model, by adding a time acquisition module to the circuit and setting up a corresponding data acquisition circuit, not only realizes the data acquisition for multi-terminal differential protection devices, but also provides time information. The circuit has higher reliability and better accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the functional modules of this utility model.

[0017] Figure 2 This is a schematic diagram of the circuit principle of the communication module of this utility model.

[0018] Figure 3 This is a schematic diagram of the circuit principle of the digital-to-analog isolation module of this utility model.

[0019] Figure 4 This is a schematic diagram of the circuit principle of the digital-to-analog conversion module of this utility model.

[0020] Figure 5 This is a schematic diagram of the circuit principle of the time acquisition module of this utility model.

[0021] Figure 6 This is a schematic diagram of the circuit principle of the alarm module of this utility model.

[0022] Figure 7 This is a schematic diagram of the circuit principle of the storage module of this utility model.

[0023] Figure 8 This is a schematic diagram of the circuit principle of the control module of this utility model. Detailed Implementation

[0024] like Figure 1The diagram shows the functional modules of this utility model: The data acquisition circuit for a multi-terminal differential protection device of a line provided by this invention includes a power supply module, a signal acquisition module, a control module, a communication module, a digital-to-analog conversion module, a digital-to-analog isolation module, a time acquisition module, an alarm module, and a storage module; the signal acquisition module, communication module, digital-to-analog isolation module, time acquisition module, alarm module, and storage module are all connected to the control module; the digital-to-analog conversion module is connected to the digital-to-analog isolation module; the power supply module supplies power to the data acquisition circuit; the signal acquisition module acquires the data information required by the multi-terminal differential protection device of the line and uploads it to the control module; the communication module is used for communication between the data acquisition circuit and external systems; the digital-to-analog conversion module receives digital signals from the digital-to-analog isolation module and converts them into analog signals for external output; the digital-to-analog isolation module receives digital signals from the control module, isolates the data, and outputs it to the digital-to-analog conversion module; the time acquisition module acquires time information and uploads the acquired time information to the control module; the alarm module receives control signals from the control module and alarms; the storage module stores the data information of the data acquisition circuit; and the control module controls the operation of the data acquisition circuit.

[0025] In specific implementation, the signal acquisition module includes a voltage signal acquisition circuit and a current signal acquisition circuit; the voltage signal acquisition circuit is used to acquire the voltage signal of the power system, and the current signal acquisition circuit is used to acquire the current signal of the power system; wherein, the voltage signal acquisition circuit can adopt the ADS1278 circuit; the current signal acquisition circuit can adopt the ADS1278 circuit.

[0026] like Figure 2The diagram shows the circuit principle of the communication module of this utility model: the communication module is a circuit composed of a communication module of model ME3630; pin 10 of the communication module is connected to the GNSS antenna GNSS_ANT; pins 22, 23, and 24 of the communication module are used to provide the USB interface of the communication module, wherein pin 22 is connected to the USB power signal USB_VBUS, pin 23 is the USB data negative pin, and pin 24 is the USB data positive pin; pins 37, 38, 39, and 40 of the communication module are connected to the SD card and obtain the corresponding data information, wherein pin 37 is used to connect to pin C3 of the SD card slot XS4 and obtain the corresponding clock signal, pin 38 is used to connect to the S Pin C7 of the SD card slot XS4 is used to obtain the corresponding data signal; pin 39 is used to connect to pin C2 of the SD card slot XS4 and obtain the corresponding reset signal RST; pin 40 is used to connect to pin C1 of the SD card slot XS4 and obtain the corresponding power signal VCC; at the same time, pins 37 to 40 of the communication module are also connected to the outside through interface U3; pins 53 and 54 of the communication module are connected to the control module and perform corresponding data interaction; pin 62 of the communication module is connected to the main signal MAIN_ANT; pins 78, 80, 3, 9, 11, 20, 21, 31, 36, 46, 49, 52, 61 and 63 of the communication module are all directly grounded.

[0027] like Figure 3 The diagram shows the circuit principle of the analog-to-digital isolation module of this invention: The analog-to-digital isolation module is a circuit composed of an isolation chip of model ISO7240CF; pin 1 of the isolation chip is connected to a 3.3V power supply signal and draws power from it, and pin 1 of the isolation chip is also grounded and filtered through a filter capacitor C169; pins 2 and 8 of the isolation chip are directly grounded; pins 4, 5, and 6 of the isolation chip are connected to the control module and obtain the corresponding model number, wherein pin 4 of the isolation chip is used to obtain the current signal, pin 5 of the isolation chip is used to obtain the clock signal, and the isolation chip... Pin 6 of the isolation chip is used to acquire control signals; pins 9 and 15 of the isolation chip are connected to analog ground GNDI; pin 10 of the isolation chip is connected to analog power supply +5VI through pull-up resistor R101 to ensure that the pin level is high; pin 13 of the isolation chip outputs the isolated current signal SPI_SDI1_I, pin 12 of the isolation chip outputs the isolated clock signal SPI_CLK_I, pin 11 of the isolation chip outputs the isolated control signal SPI_LDAC_I; pin 16 of the isolation chip is directly connected to analog power supply signal +5VI and draws power from it.

[0028] The digital-to-analog isolation module includes several identical channels, which are respectively connected to the control module and output corresponding signals SPI_CS_N_I and SPI_LOAD_N_I.

[0029] like Figure 4The diagram shown illustrates the circuit principle of the digital-to-analog converter module of this invention: The digital-to-analog converter module is a circuit composed of a DAC7734EC digital-to-analog converter chip; pins 11 and 9 of the digital-to-analog converter chip are connected to the digital-to-analog isolation module and acquire the corresponding signals SPI_CS_N_I and SPI_LOAD_N_I; pin 5 of the digital-to-analog converter chip is connected to... Figure 3 Pin 12 of the intermediate isolation chip is connected to obtain the clock signal; pin 3 of the digital-to-analog converter chip is connected to... Figure 3 Pin 13 of the intermediate isolation chip is connected to acquire the current signal; pin 7 of the digital-to-analog converter chip is connected to... Figure 3 Pin 11 of the intermediate isolation chip receives the control signal; pins 15 and 17 of the digital-to-analog converter chip are both reset pins. Pin 15 is connected to the analog power signal +5VI via pull-up resistor R5 to ensure pin level stability; pin 17 of the digital-to-analog converter chip is connected to the analog power signal +5VI via pull-up resistor R6 to ensure pin level stability; pins 23 and 24 of the digital-to-analog converter chip are power signal pins, directly connected to the analog power signal +5VI, which is also grounded and filtered via filter resistors C3 and C13; pins 4, 6, 10, 12, 14, 16, 18, 21, and 22 of the digital-to-analog converter chip are all ground pins and are directly grounded; pins 47 and 48 of the digital-to-analog converter chip are the positive pins of the first current output and output the first... The first digital-to-analog converter (DAC) chip has four power supply pins: pin 1 (iOUTA1+) and pin 2 (iOUTB1+). Pins 40 and 39 are the second current output positive pins, outputting the second current positive signal iOUTB1+. Pins 38 and 37 are the third current output positive pins, outputting the third current positive signal iOUTC1+. Pins 32 and 31 are the fourth current output pins, outputting the fourth current signal iOUTA+. Pins 25 and 26 are the second power supply pins, connected to the +15V power signal +15VI. Pins 29, 30, and 45 are the third power supply pins, connected to the -15V power signal -15VI. Pins 27, 28, and 46 are the analog ground pins, directly connected to the analog ground GNDI.

[0030] Chip U7 is a reference voltage chip. Pin 2 of chip U7 is connected to the +15V power supply signal (+15VI) and draws power from it. Pin 2 is also grounded and filtered through filter capacitor C45. Pin 4 of chip U7 is directly grounded. Pin 6 of chip U7 is the output pin, outputting the reference voltage VREF+. Pin 6 is also grounded and filtered through filter capacitor C56. The reference voltage VREF+ is divided into three paths. The first path connects to the positive input of the first operational amplifier (op-amp) via resistor R83. The negative input of the first op-amp is directly connected to pin 41 of the digital-to-analog converter (DAC) chip, providing the first reference voltage signal. The output of the first op-amp, after current limiting through resistor R82, is connected to pin 42 of the DAC chip, providing the second reference voltage signal. The third path of the reference voltage VREF+ is connected to the positive input of the third op-amp via resistor R81. The negative input of the third op-amp is directly connected to pin 36 of the DAC chip, providing the fifth reference voltage signal. The output of the third op-amp, after current limiting through resistor R80, is directly... The first reference voltage (VREF+) is connected to pin 35 of the digital-to-analog converter (DAC) chip and provides the sixth reference voltage signal. The second reference voltage (VREF+) is connected to the negative input of the fifth op-amp, whose positive input is directly grounded. The fifth op-amp acts as an inverter, therefore its output is a negative reference voltage (VREF-). This negative reference voltage (VREF-) is divided into two paths. The first path (VREF-) is connected to the positive input of the second op-amp via resistor R52. The negative input of the second op-amp is directly connected to pin 44 of the DAC chip and provides the fourth reference voltage signal. The output of the second op-amp, after current limiting via resistor R51, is connected to pin 43 of the DAC chip and provides the third reference voltage signal. The second path (VREF-) is connected to the positive input of the fourth op-amp via resistor R50. The negative input of the fourth op-amp is directly connected to pin 33 of the DAC chip and provides the eighth reference voltage signal. The output of the fourth op-amp, after current limiting via resistor R49, is connected to pin 34 of the DAC chip and provides the seventh reference voltage signal.

[0031] like Figure 5The diagram shows the circuit principle of the time acquisition module of this utility model: The time acquisition module is a circuit composed of a timing chip of model LEA-6T; pins 3 and 28 of the timing chip are connected to the control module and exchange time data; pin 6 of the timing chip is directly connected to the 3.3V power supply signal 3V3; pins 7, 13 and 14 of the timing chip are all directly grounded; pin 10 of the timing chip is the reset pin, which is connected to the 3V3 power supply signal through resistor R131 to ensure the stability of the pin level; Pins 26, 15, 16, and 17 of the timing chip are all directly grounded. Pin 19 of the timing chip, after passing through the LC filter circuit C177 and LB3, is connected to the 3V3 power supply signal and obtains the antenna power signal through the current-limiting resistor R123. Pin 20 of the timing chip, after being current-limited by resistor R127, obtains a power signal with the same current as the antenna power signal through the current mirror circuit (composed of transistors Q1 and Q2, resistors R124, R125, and R126 in the figure) to ensure the normal operation of the timing chip.

[0032] like Figure 6 The diagram shows the circuit principle of the alarm module of this utility model: the alarm module is a circuit composed of a MOSFET and a buzzer; the alarm signal BEEP issued by the control module is connected to the gate of the MOSFET; the source of the MOSFET is directly connected to the 3.3V power supply signal 3V3; the gate of the MOSFET is also connected to the 3V3 power supply signal through the pull-up resistor R134 to ensure the stability of the pin level; the drain of the MOSFET is grounded through the buzzer B1 and the resistor R133.

[0033] However, when the alarm signal BEEP is high, the MOSFET Q3 is cut off and the buzzer does not work; when the alarm signal BEEP is low, the MOSFET Q3 is turned on, and the buzzer works and sounds an alarm.

[0034] like Figure 7 The diagram shows the circuit principle of the storage module of this utility model: The storage module is a circuit composed of a storage chip of model W25Q256JVEIQ; pin 1 of the storage chip is connected to the control module and obtains the control signal; pins 2 and 5 of the storage chip are connected to the control module and perform data interaction; pin 3 of the storage chip is connected to the control module and obtains the data direction control signal; pins 4 and 9 of the storage chip are directly grounded; pin 6 of the storage chip is connected to the control module and obtains the corresponding clock signal; pin 7 of the storage chip is connected to the control module and obtains the control signal; pin 8 of the storage chip is connected to the 3.3V power supply signal 3V3 and draws power; at the same time, pin 8 of the storage chip is also grounded and filtered through capacitor C216; pin 1 of the storage chip is also connected to the 3.3V power supply signal 3V3 through pull-up resistor R146 to ensure the stability of the pin level.

[0035] like Figure 8The diagram shows the circuit principle of the control module of this utility model: The control module is a circuit composed of a control module of model Z7-204P-CORE; pins 1, 3, 5, 7, 9, and 11 of the control module are directly connected to the 3V3 power supply signal and are powered by it, and are also grounded and filtered through grounding capacitors C202 and C204; pins 105, 107, 111, 113, 117, 119, 123, 125, 129, 131, 135, and 137 of the control module are data signal input pins, which are directly connected to the sensor and acquire the corresponding sampling data; pins 13, 15, 17, 19, 51, 55, 59, 61, 67, 73, 79, 85, 91, 97, 103, 109, and 115 of the control module are also connected to the control module. Pins 121, 127, 133, 139, 145, 151, 157, 163, 169, 175, 181, 187, 193, 199, 106, 28, 6, and 12 are all directly grounded. Pins 35, 37, 39, 41, 43, and 45 of the control module are all connected to the storage module. Pin 35 is used for user output control signals, pins 37 and 39 for user data interaction, pin 41 is used for outputting data direction signals, pin 43 is used for outputting reset signals, and pin 45 is used for outputting clock signals. Pin 204 of the control module is used to output the alarm signal BEEP to the alarm module. Pins 192 and 194 of the control module are signal pins, which are connected to pins 28 and 3 of the timing chip of the time acquisition module in sequence, and are used for clock data interaction. Pin 138 of the control module... Pins 140, 142, 144, 146, 148, 150, 152, 154, and 156 are digital signal output pins, which connect to the digital-to-analog isolation module and output digital signals. Pins 68 and 104 of the control module are communication pins, which directly connect to the communication module and perform data exchange. Pins 2 and 4 of the control module are connected to the 2V5 power supply signal and powered by it, while pins 8 and 10 are connected to the 1V8 power supply signal and powered by it. Pin 63 of the control module is connected to the 2V5 power supply signal through LED HL1 and resistor R145. The control module monitors the 2V5 power supply signal by the pin level of pin 63 and the state of LED HL1. At the same time, the working status of the control module can also be monitored by the state of LED HL1.

Claims

1. A data acquisition circuit for a multi-terminal differential protection device for lines, characterized in that... It includes a power supply module, a signal acquisition module, a control module, a communication module, a digital-to-analog converter module, a digital-to-analog isolation module, a time acquisition module, an alarm module, and a storage module; the signal acquisition module, communication module, digital-to-analog isolation module, time acquisition module, alarm module, and storage module are all connected to the control module; the digital-to-analog converter module is connected to the digital-to-analog isolation module; the power supply module is used to supply power to the data acquisition circuit; the signal acquisition module is used to acquire the data information required by the multi-terminal differential protection device and upload it to the control module; The communication module is used for the data acquisition circuit to communicate with external devices; The digital-to-analog converter module receives digital signals from the digital-to-analog isolation module and converts them into analog signals for output. The digital-to-analog isolation module receives digital signals from the control module, isolates the data, and outputs them to the digital-to-analog conversion module; the time acquisition module acquires time information and uploads the acquired time information to the control module. The alarm module is used to receive control signals from the control module and issue an alarm; the storage module is used to store the data information of the data acquisition circuit; and the control module is used to control the operation of the data acquisition circuit.

2. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The signal acquisition module includes a voltage signal acquisition circuit and a current signal acquisition circuit; the voltage signal acquisition circuit is used to acquire the voltage signal of the power system, and the current signal acquisition circuit is used to acquire the current signal of the power system.

3. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The control module is a circuit consisting of a control module of model Z7-204P-CORE.

4. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The communication module is a circuit consisting of a communication module of model ME3630.

5. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The digital-to-analog converter module is a circuit composed of a DAC7734EC digital-to-analog converter chip.

6. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The digital-to-analog isolation module is a circuit composed of an isolation chip of model ISO7240CF.

7. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The time acquisition module is a circuit composed of a timing chip of model LEA-6T.

8. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The alarm module is a circuit consisting of a MOSFET and a buzzer.

9. The data acquisition circuit for a multi-terminal differential protection device for lines according to claim 1, characterized in that... The storage module is a circuit composed of storage chips with the model number W25Q256JVEIQ.

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