Isolation type voltage sampling test system

Abstract

The utility model provides an isolation type voltage sampling test system. The isolation type voltage sampling test system comprises an auxiliary power supply module, a main controller, a voltage sampling module, a resistance voltage dividing module and a display module, the auxiliary power supply module is used for converting alternating-current mains supply into direct-current power supply so as to supply power to the main controller and the voltage sampling module; the resistance voltage division module is used for performing voltage division on the tested high-voltage source; the voltage sampling module is used for isolating and amplifying the voltage division signal output by the resistance voltage division module; and the main controller communicates with the voltage sampling module and the display module through optical fibers, and receives an isolation amplification signal output by the voltage sampling module so as to display a sampled voltage waveform on the display module in real time. According to the voltage sampling circuit, the safety risk caused by high-voltage sampling can be effectively avoided, the personal safety of testers is guaranteed, the requirement of long-distance measurement can be met, and common-mode interference caused by common ground of traditional voltage sampling can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to an isolated voltage sampling and testing system. Background Art

[0002] Frequency converters are widely used in industrial control systems, including fans, pump stations, conveyors, compressors, and other equipment and systems. They offer advantages such as energy saving, precise control, smooth start-up and shutdown, and reduced wear on mechanical equipment. In practical applications, they can improve production efficiency and reduce energy consumption and maintenance costs.

[0003] Cascaded high-voltage inverters achieve high-voltage output by connecting multiple low-power inverter units in series and then summing their outputs. Due to their high-voltage nature, cascaded high-voltage inverters have higher input and output voltages than typical inverters, often reaching 3kV to 10kV. This exceeds the measurement voltage range of typical differential probes. Because differential probes are in direct contact with the high-voltage source being measured and lack effective isolation, they pose a risk of damage and pose a significant threat to the safety of R&D personnel during debugging. Utility Model Content

[0004] The present application provides an isolated voltage sampling and testing system to solve the problem of existing voltage sampling. Since the differential probe is in direct contact with the high-voltage source being measured and there is no effective isolation, there is a risk of damage to the differential probe, which also poses a great threat to the personal safety of R&D personnel.

[0005] The present application provides an isolated voltage sampling and testing system, comprising an auxiliary power supply module, a main controller, a voltage sampling module, a resistor voltage divider module, and a display module;

[0006] The auxiliary power supply module is used to convert AC mains power into DC power to power the main controller and the voltage sampling module;

[0007] The resistance voltage divider module is used to divide the voltage of the high voltage source to be measured;

[0008] The voltage sampling module is used to isolate and amplify the voltage division signal output by the resistance voltage division module;

[0009] The main controller communicates with the voltage sampling module and the display module via optical fibers, receives the isolated amplified signal output by the voltage sampling module, and displays the sampled voltage waveform on the display module in real time.

[0010] In one example, the auxiliary power module includes an isolated power module.

[0011] In one example, the resistor voltage divider module includes a voltage input terminal, a voltage divider circuit composed of voltage divider resistors, and a voltage output terminal;

[0012] The voltage of the high-voltage source to be measured is input from the voltage input terminal, and is output from the voltage output terminal after being divided by the voltage divider circuit.

[0013] In one example, the voltage sampling module includes an input voltage sampling terminal, an optocoupler isolation circuit, an operational amplifier conditioning circuit, an analog-to-digital converter, and a processor;

[0014] The voltage division signal output by the resistor voltage division module passes through the input voltage sampling terminal, is isolated by the optical coupler isolation circuit, and then amplified by the operational amplifier conditioning circuit;

[0015] The analog-to-digital converter is used to convert the amplified signal into a digital signal, and then output it to the main controller after being processed by the processor.

[0016] In one example, the operational amplifier conditioning circuit includes a differential amplifier and a non-inverting amplifier. The differential amplifier performs differential amplification on the signal isolated and processed by the optocoupler isolation circuit, and then the non-inverting amplifier performs non-inverting amplification processing and outputs the signal.

[0017] In one example, the processor includes an FPGA (Field Programmable Gate Array).

[0018] In one example, the main controller includes a main control core board, which communicates with the voltage sampling module and the display module through optical fiber, receives the isolated amplified signal output by the voltage sampling module, and displays the sampled voltage waveform in real time on the display module.

[0019] In one example, the display module includes a portable computer.

[0020] In one example, a voltage differential probe is further included, the input end of the voltage differential probe is connected to the voltage source to be measured to obtain the voltage signal of the voltage source to be measured, that is, the low voltage signal; the output end of the voltage differential probe is connected to the voltage sampling module.

[0021] The isolated voltage sampling test system provided in this application can effectively avoid the safety risks caused by high-voltage sampling through the voltage sampling circuit, thereby ensuring the personal safety of the testers. The main controller and the voltage sampling module transmit signals through optical fiber, which can not only meet the needs of long-distance measurement, but also effectively avoid the common-mode interference caused by the common ground of traditional voltage sampling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0023] Figure 1 Schematic diagram of an isolated voltage sampling and testing system provided in an embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of a resistor voltage divider module provided in an embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of a voltage sampling module provided in an embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of an isolated voltage sampling and testing system provided in another embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to facilitate understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art in the technical field of this application. The terms used in this specification and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0028] like Figure 1 As shown, an isolated voltage sampling and testing system provided by an embodiment of the present application includes an auxiliary power supply module, a main controller, a voltage sampling module, a resistor voltage divider module, and a display module.

[0029] The auxiliary power module is comprised of an isolated power supply module, such as an isolated switching power supply, with an integrated control feedback circuit. This module converts 220VAC AC mains power into a stable 15VDC DC power supply to power the back-end main controller and voltage sampling module. The isolated power supply module can be referenced to existing technologies and is not limited here.

[0030] The resistor voltage divider module is used to divide the voltage of the high voltage source to be measured. Figure 2 As shown, the resistor voltage divider module includes voltage divider resistors R1~R11, voltage input terminal P1, and voltage output terminal P2. The three-phase high voltage of the high-voltage source to be measured is input from the voltage input terminal P1, and after being divided to a low voltage by the voltage divider circuit composed of the voltage divider resistors R1~R11, it is output from the voltage output terminal P2.

[0031] Specifically, the three-phase high voltage is divided into three phases: A, B, and C. The A-phase voltage UinA is connected to resistor R1 via the voltage input terminal P1. Resistor R1 is connected in series with resistors R2 and R3, and then connected to the voltage output terminal P2, thereby outputting the A-phase voltage UoutA. The B-phase voltage UinB is connected to resistor R4 via the voltage input terminal P1. Resistor R4 is connected in series with resistors R5 and R6, and then connected to the voltage output terminal P2, thereby outputting the B-phase voltage UoutB. The C-phase voltage UinC is connected to resistor R7 via the voltage input terminal P1. Resistor R7 is connected in series with resistors R8 and R9, and then connected to the voltage output terminal P2, thereby outputting the C-phase voltage UoutC. One end of resistor R10 is connected to resistor R3, and the other end of resistor R10 is connected to resistor R6. One end of resistor R11 is connected to resistor R6, and the other end of resistor R11 is connected to resistor R9.

[0032] The voltage sampling module is used to isolate and amplify the voltage division signal output by the resistance voltage division module.

[0033] like Figure 3 As shown, the voltage sampling module includes an input voltage sampling terminal P3, an optocoupler isolation circuit, an operational amplifier conditioning circuit, an ADC (analog-to-digital converter) and a processor.

[0034] After the voltage-dividing signal output by the resistor voltage-dividing module passes through the input voltage sampling terminal P3, the differential voltages UA and UB are input to the front end of the optocoupler isolator U1 (constituting the optocoupler isolation circuit of this path). After the optocoupler isolator U1 performs isolation processing, it is connected to the differential amplifier U4. The differential amplifier U4 performs differential amplification on the isolated signal and outputs it to the same-direction amplifier U7 for same-direction amplification. The resistance value of the resistor R1 can be adjusted to change the amplification factor of the same-direction amplifier U7 (the differential amplifier U4 and the same-direction amplifier U7 constitute the operational amplifier conditioning circuit of this path, which is similar below); the differential voltages UB and UC are input to the optocoupler isolator U 2, the optical coupler isolator U2 is connected to the differential amplifier U5 after isolation processing, the differential amplifier U5 performs differential amplification on the isolated signal and outputs it to the same-direction amplifier U8 for same-direction amplification, wherein the resistance value of the adjusting resistor R2 can change the amplification factor of the same-direction amplifier U8; the differential voltages UA and UC are input to the front end of the optical coupler isolator U3, the optical coupler isolator U3 is connected to the differential amplifier U6 after isolation processing, the differential amplifier U6 performs differential amplification on the isolated signal and outputs it to the same-direction amplifier U9 for same-direction amplification, wherein the resistance value of the adjusting resistor R3 can change the amplification factor of the same-direction amplifier U9.

[0035] The same-direction amplified signals output by the same-direction amplifiers U7, U8, and U9 are converted into digital signals by an analog-to-digital converter, and then processed by a processor before being output (for example, communication processing with the main controller).

[0036] The main controller includes a main control core board, which communicates with the voltage sampling module through optical fiber, receives data sampled by the voltage sampling module, and communicates with the display module to display the sampled voltage waveform on the display module in real time.

[0037] The display module includes a portable computer, which communicates with the main controller through optical fiber and is connected to the computer host computer. The voltage waveform can be viewed in real time and recorded and saved in the background software.

[0038] Figure 4 This is an isolated voltage sampling and testing system provided by another embodiment of the present application. Figure 1 What is different from the example is that it also includes a voltage differential probe. The input end of the voltage differential probe is connected to the voltage source to be measured to obtain the low-voltage signal of the voltage source to be measured; the output end of the voltage differential probe is connected to the voltage sampling module, and the voltage differential probe processes the collected voltage signal and sends it to the voltage sampling module. The voltage sampling module transmits the voltage signal output by the voltage differential probe to the display module through optical fiber. By configuring the corresponding attenuation multiples through the background software, the voltage waveform signal collected by the voltage differential probe can be displayed, which not only meets the needs of long-distance isolated sampling, but also solves the common-mode interference signal brought by the voltage differential probe.

[0039] It should be noted that the preferred embodiments of the present application are given in the specification and drawings of this application. However, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of this application. The purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive. In addition, the above-mentioned technical features can be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the description of this application; further, it is obvious to those skilled in the art that improvements or changes can be made based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. An isolated voltage sampling and testing system, characterized in that: It includes auxiliary power supply module, main controller, voltage sampling module, resistance voltage divider module and display module; The auxiliary power supply module is used to convert AC mains power into DC power to power the main controller and the voltage sampling module; The resistance voltage divider module is used to divide the voltage of the high voltage source to be measured; The voltage sampling module is used to isolate and amplify the voltage division signal output by the resistance voltage division module; The main controller communicates with the voltage sampling module and the display module via optical fibers, receives the isolated amplified signal output by the voltage sampling module, and displays the sampled voltage waveform on the display module in real time.

2. The isolated voltage sampling and testing system as claimed in claim 1, wherein: The auxiliary power supply module includes an isolated power supply module.

3. The isolated voltage sampling and testing system as claimed in claim 1, wherein: The resistor voltage divider module includes a voltage input terminal, a voltage divider circuit composed of voltage divider resistors, and a voltage output terminal; The voltage of the high-voltage source to be measured is input from the voltage input terminal, and is output from the voltage output terminal after being divided by the voltage divider circuit.

4. The isolated voltage sampling and testing system as claimed in claim 1, wherein: The voltage sampling module includes an input voltage sampling terminal, an optocoupler isolation circuit, an operational amplifier conditioning circuit, an analog-to-digital converter, and a processor; The voltage division signal output by the resistor voltage division module passes through the input voltage sampling terminal, is isolated by the optical coupler isolation circuit, and then amplified by the operational amplifier conditioning circuit; The analog-to-digital converter is used to convert the amplified signal into a digital signal, and then output it to the main controller after being processed by the processor.

5. The isolated voltage sampling and testing system as claimed in claim 4, characterized in that: The operational amplifier conditioning circuit includes a differential amplifier and a non-inverting amplifier. The differential amplifier performs differential amplification on the signal isolated and processed by the optical coupler isolation circuit, and then the non-inverting amplifier performs non-inverting amplification processing and outputs the signal.

6. The isolated voltage sampling and testing system as claimed in claim 4, characterized in that: The processor includes an FPGA.

7. The isolated voltage sampling and testing system as claimed in claim 1, wherein: The main controller includes a main control core board, and the main control core board communicates with the voltage sampling module and the display module through optical fibers.

8. The isolated voltage sampling and testing system as claimed in claim 1, wherein: The display module includes a portable computer.

9. The isolated voltage sampling and testing system as claimed in claim 1, wherein: It also includes a voltage differential probe, the input end of which is connected to the voltage source to be measured to obtain the low voltage signal of the voltage source to be measured; the output end of the voltage differential probe is connected to the voltage sampling module.

Images