Analog quantity module for automatic tester of protection device

Abstract

The utility model discloses an analog quantity module for an automatic tester of a protection device, which comprises an upper computer and a CPU (central processing unit), and the CPU is connected with an alternating-current source module, a direct-current source module, a switching value module, an analog quantity module and a communication module. The CPU processor comprises an information collection unit and an information comparison unit, the information collection unit is connected with the AC / DC voltage and current source module, the switching value input and output module, the analog quantity input and output module and the communication detection module, and the information comparison unit is connected with the human-computer interface module. Compared with the prior art, an analog quantity small signal channel is additionally arranged on the basis of the original version, and the protection tester host can collect analog quantity or output analog quantity through analog quantity small signals, so that the function of the protection tester is expanded.

Description

Technical Field

[0001] The utility model relates to the technical field of relay protection device testers, in particular to an analog quantity module for an automatic tester of a protection device. Background Art

[0002] Power protection devices are the most fundamental and effective protective measure to ensure the normal operation of power systems. However, existing manual testing methods must be reconsidered, requiring significant improvements in production testing efficiency to reduce increasingly high labor costs. Traditional protection device testers involve cumbersome manual testing processes and complex testing methods, with no established testing specifications. Furthermore, power protection devices require high-precision testing, limiting improvements in labor efficiency. Existing relay protection device testers lack analog small signal channels. To expand the functionality of relay protection device testers, an analog acquisition and output module must be added to the existing relay protection device testers. Utility Model Content

[0003] In view of the problems existing in the prior art, the utility model discloses an analog quantity module for an automatic tester for a protection device, comprising a host computer and a CPU processor, wherein the CPU processor is connected to an AC source module, a DC source module, a switching quantity module, an analog quantity module and a communication module; the CPU processor comprises an information collection unit and an information comparison unit, the information collection unit is connected to an AC / DC voltage and current source module, a switching quantity input and output module, an analog quantity input and output module and a communication detection module, and the information comparison unit is connected to a human-machine interface module; the AC source module and the DC source module comprise a voltage regulator, a transformer, a rectifier and filter circuit, a high-power resistor, a relay and a contactor; the switching quantity input and output module comprises a switching quantity input circuit and a switching quantity output circuit; the AC source module and the DC source module, the switching quantity input and output module, the analog quantity input and output module and the communication detection module are led out through an aviation plug and a test line, and the test line is connected to a fixture test pin; the ADC chip in the analog quantity input and output module uses one AD7060 chip and one AD7606-4 chip, and the DAC chip uses two AD5668 chips.

[0004] As a preferred technical solution of the present invention, the CPU processor selects STM32F407VET6 and communicates with the ADC chip and the DAC chip via SPI.

[0005] As a preferred technical solution of the present invention, the CPU processor communicates with the host computer via a CAN bus.

[0006] Beneficial effects of the present invention: The present invention adds an analog small signal channel on the basis of the original version, and the protection tester host can collect analog quantities or output analog quantities through the analog small signal, thereby expanding the functions of the protection tester. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the specific embodiments or the description of the prior art. In all the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0008] Figure 1 This is a schematic diagram of the principle of the automatic tester for the protection device of the utility model;

[0009] Figure 2 This is a communication diagram of the analog input and output module of the utility model;

[0010] Figure 3 This is the connection circuit diagram of the AD7606 and AD7606-4 chips and STM32 of the utility model;

[0011] Figure 4 This is the connection circuit diagram between the AD5668 chip and STM32 of the utility model; DETAILED DESCRIPTION

[0012] Example 1

[0013] like Figures 1 to 4As shown, the utility model discloses an analog quantity module for an automatic tester of a protection device, comprising a host computer and a CPU processor, wherein the CPU processor is connected to an AC source module, a DC source module, a switching quantity module, an analog quantity module and a communication module; the CPU processor comprises an information collection unit and an information comparison unit, the information collection unit is connected to an AC / DC voltage and current source module, a switching quantity input and output module, an analog quantity input and output module, and a communication detection module, and the information comparison unit is connected to a human-machine interface module; the AC source module and the DC source module comprise a voltage regulator, a transformer, a rectifier and filter circuit, a high-power resistor, a relay, and a contactor; the switching quantity input and output module comprises a switching quantity input circuit and a switching quantity output circuit; the AC source module and the DC source module, the switching quantity input and output module, the analog quantity input and output module, and the communication detection module are led out through an aviation plug and a test line, and the test line is connected to a fixture test pin; the ADC chip in the analog quantity input and output module uses one AD7060 chip and one AD7606-4 chip, and the DAC chip uses two AD5668 chips. The AD7606 is a 16-bit, 8-channel, simultaneous sampling analog-to-digital data acquisition system (DAS), while the AD7606-4 is a 16-bit, 4-channel, simultaneous sampling analog-to-digital data acquisition system. Since the module requires 12 channels of A / D conversion, we need two ADC chips, the AD7606 and AD7606-4, to form the analog data acquisition system. The AD5668 is a low-power, octal, 16-bit, buffered voltage-output DAC. Since our module requires 12 A / D conversion channels, we need two AD5668 chips to form the analog output system.

[0014] The working principle of the utility model is as follows: the AC source module and the DC source module, the switching input and output module, the analog input and output module, and the communication detection module of the automatic tester for the protection device are led out through the aviation plug and the test line, the test line is connected to the test pin of the fixture, and the test pin is connected to the device under test through the guide rail and the locking device of the fixture, so that the automatic tester for the protection device does not need to repeatedly disassemble and install the test line when testing different circuits of the same device and different devices, which greatly improves the testing efficiency.

[0015] The automatic tester for protection devices automatically identifies whether the test results are correct according to unified standards and displays the results in a centralized manner to avoid human operational errors. In addition, the automatic tester for protection devices adds a communication detection circuit to detect whether the communication circuit of the relay protection device is intact to avoid misjudgment. Moreover, the automatic tester for protection devices serves as the communication host computer and the relay protection device under test serves as the communication slave computer, which can accurately and quickly identify the quality of the communication hardware.

[0016] The test process of the automatic tester for protection devices: First, set the parameters through the human-machine interface, automatically send analog and digital signals, then obtain the corresponding data of the protection device to be tested from the communication interface according to the communication protocol, compare the sent analog and digital signals with the data retrieved through communication, and automatically make a test conclusion; the test conclusion includes the test conclusions of the analog part, switching part, and protection part of the protection device.

[0017] Each component of the ADC chip features built-in analog input lockout protection, a second-order antialiasing filter, a track-and-hold amplifier, a 16-bit charge-redistribution successive pass analog-to-digital converter (ADC), a flexible digital filter, a 2.5V reference voltage source, a reference voltage buffer, and high-speed serial and parallel interfaces. The AD_SPI_SCK_PIN is connected to DB7, while the remaining pins DB0-DB6 and DB8-DB15 are grounded. A low level for PAR / SER / BYTE SEL enables parallel mode, while a high level enables serial mode. The MCU uses a Microchip SPI interface RAM chip. The ADC chip transmits data to the STM32 via the serial interface, which in turn communicates with the protection device tester's CPU via the CAN bus.

[0018] The AD5668 is a low-power, octal, 16-bit buffered voltage-output DAC. All devices operate from a single 2.7V to 5.5V supply with guaranteed monotonicity. The AD5668 is available in a 4mm × 4mm LFCSP and a 16-lead TSSOP package. The AD5668-1 features a 1.25V 5ppm / °C reference with a full-scale output range of 2.5V. The onboard reference is disabled at power-up, allowing the use of an external reference. The internal reference is enabled via a software write. The device also includes a power-on reset circuit that ensures the DAC outputs are powered up to 0V and remain powered until a valid write is made. A power-down feature reduces the device's current consumption to 400nA at 5V. SYNC (synchronization input signal for the data frame) is active low. When the SYNC pin is low, the input shift register is enabled to transfer data on the falling edge of the clock signal. The DAC is updated after the 24th clock cycle. (If the SYNC signal is pulled high before the 24th clock cycle, the write sequence is ignored.) SCLK (serial clock input signal): Data transfer rates up to 30 MHz. Din (serial data input signal): Data (0 or 1) is written to the 24-bit input shift register on each falling edge of the SCLK clock input signal. The ADC chip transmits data to the STM32 via a serial interface, which in turn communicates with the protection device tester's CPU motherboard via the CAN bus.

[0019] Components not described in detail herein are prior art.

[0020] Although the specific embodiments of the present invention are described in detail above, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by ordinary technicians in this field, various changes can be made without departing from the purpose of the present invention. Modifications or deformations that do not involve creative work are still within the scope of protection of the present invention.

Claims

1. An analog module for an automatic tester for a protection device, characterized by: The system comprises a host computer and a CPU processor, wherein the CPU processor is connected to an AC source module, a DC source module, a switching module, an analog module and a communication module; the CPU processor comprises an information collection unit and an information comparison unit, the information collection unit is connected to an AC / DC voltage and current source module, a switching input and output module, an analog input and output module and a communication detection module, and the information comparison unit is connected to a human-machine interface module; the AC source module and the DC source module comprise a voltage regulator, a transformer, a rectifier and filter circuit, a high-power resistor, a relay and a contactor; the switching input and output module comprises a switching input circuit and a switching output circuit; the AC source module and the DC source module, the switching input and output module, the analog input and output module and the communication detection module are led out through an aviation plug and a test line, and the test line is connected to a fixture test pin; the ADC chip in the analog input and output module is an AD7060 chip and an AD7606-4 chip, and the DAC chip is two AD5668 chips.

2. The analog quantity module for an automatic tester for a protection device according to claim 1, characterized in that: The CPU processor is STM32F407VET6, which communicates with the ADC chip and the DAC chip via SPI.

3. The analog quantity module for an automatic tester for a protection device according to claim 1, characterized in that: The CPU processor communicates with the host computer via the CAN bus.

4. The analog quantity module for an automatic tester for a protection device according to claim 1, characterized in that: The ADC chip has built-in analog input binning protection, a second-order anti-aliasing filter, a track-and-hold amplifier, a 16-bit charge redistribution successive approximation analog-to-digital converter (ADC), a digital filter, a 2.5V reference voltage source, a reference voltage buffer, and high-speed serial and parallel interfaces.

5. The analog quantity module for an automatic tester for a protection device according to claim 1, characterized in that: The AD5668 chip has a built-in power-on reset circuit.

6. The analog module for an automatic tester for a protection device according to claim 1, characterized in that: The ADC chip is connected to the STM32 through a serial interface.

7. The analog quantity module for the automatic tester of a protection device according to claim 6, characterized in that: The STM32 is connected to the CPU mainboard of the protection device tester via a CAN bus.

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