Construction of the hottest switching power supply

2022-09-23
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Establishment and practice of switching power supply virtual test platform based on HP, i/o library

1 introduction

in recent years, the test technology has been developing continuously, and the signal acquisition, control, analysis, processing and result expression are more intuitive and efficient. If computer technology and instrument technology can be combined to realize the functions of signal acquisition, control, analysis, processing, data expression and output, it will usher in a leap in testing technology. If the signal acquisition and control is made into a plug-in and inserted into the bus expansion slot of the computer; The signal analysis, processing and result expression are realized by the application software installed in the computer. Thus, the combination of testing instrument and computer is realized, and virtual instrument is produced. Virtual instrument refers to computer instrument with instrument software panel, which is usually composed of computer, modular functional hardware and application software

2 hardware configuration and data transmission of the virtual test platform

the working process of the virtual test platform can be described as follows: the modular functional hardware generates the corresponding output according to the user instructions given by the application software; The modular functional hardware carries out data communication according to the protocol and transmits the output data signal of the modular functional hardware to the computer; The application software analyzes and processes the collected data, completes the collection, analysis, display, storage and data generation of the tested quantity, and displays it in the graphical interface. Then, how to configure hardware and transmit data between computer and virtual instrument

GPIB interface instrument is the most widely used virtual instrument. Install the plug-in GPIB interface card in the expansion slot of the computer, and connect the GPIB interface card of the virtual instrument with the GPIB interface card of the computer with GPIB cable. This completes the hardware configuration of data transmission between computer and virtual instrument. Install the driver of the virtual instrument and set the GPIB address of the virtual instrument. GPIB program package has the functions of automatic addressing and bus management. It uses a computer to control the bus and transmit instrument instructions on the bus. The format of instrument instruction is SCPI. GPIB instrument accepts SCPI instruction and generates corresponding output. If users master SCPI instruction, they can program the output of the instrument directly. By using SCPI instructions and GPIB interface, programmable instruments are closely connected with computers, so that electronic measurement is developed from manual operation of a single instrument to the establishment of a large-scale automatic test system [1]

3 establishment and practice of virtual test platform for switching power supply

from avionics to uninterruptible power supply, customers require the power supply to work normally when the AC power supply fluctuates and the load deteriorates. In order to ensure the performance of power supply, it is necessary to establish an advanced and digital test platform. Virtual test platform has become the first choice of this kind of test platform because of its strong scalability and friendly operation interface

Figure 1 system structure block diagram of the test platform

3.1 system block diagram

the structure block diagram of the virtual test platform is shown in Figure 1. Therefore, 1 in the test process, we must regularly check the temperature, vibration and internal wires of the electromechanical system. It can be described as: according to the requirements of the EUT performance indicators of the tested unit, the AC power supply simulates the voltage that may occur in the actual work of the EUT, and the electronic load simulates the load that may occur in the actual work of the EUT. Both voltage and load change with time. The output data signals of AC power supply and electronic load are transmitted to the computer. The application software analyzes and processes the data signals and displays them in the GUI. The data acquisition and switching unit module is used for real-time and offline data analysis and statistics with the word "grounding" or grounding mark. The output of AC power supply and electronic load can be controlled through the front panel of the instrument or through the soft panel. Therefore, the experimenters can carry out complex testing without mastering the complex functions of the front panel

the virtual test platform in this paper is constructed by HP series virtual instruments, specifically: the AC power supply is hp6813b AC power supply/analyzer; The electronic load is HP 6050a electronic load; Data acquisition and switching units are HP

34970A data acquisition, but about 50% are new and customized/switching units; The data acquisition card is IEEE-488 GPIB interface card

3.2 system software

to realize the whole working process, in addition to connecting the main computer layer and the virtual instrument according to figure 1, the GPIB address (i.e. GPIB address) of each virtual instrument should be set. The setting of HPIB address is completed by the system software of the virtual test platform. The system software mainly includes: (a) HP i/o library, including I-O setting software, local server, message browser, etc; (b) HPIB toolbox, namely interactive HPIB application software. The system software is mainly used to add experimental instruments, set the HPIB address of instruments, and define the communication mode between experimental instruments and computers. As long as the virtual instrument is connected to the host computer according to figure 1, and the driver of the instrument is installed, the virtual test platform can be set up and managed

3.3 application software

most test instruments have complex functions and are difficult to master in a short time. GUI allows users to skillfully operate the instrument without learning the functions of the front panel. The GUI of the virtual test platform established in this paper mainly has the first test point: (a) HP AC source/analyzer GUI; (B) HP voltage and frequency disturbance immunity test software vfdit (voltage and frequency disturbance immunity test); (c) HP harmonic and flicker test software HFTS (harmoniumicker

test system); (d) HP benehlink data acquisition and analysis software is used for real-time and non real-time data analysis and statistics

3.3.1 HP AC source/analyzer GUI

HP AC source/analyzer GUI is used to control the soft panel of HP AC source/analyzer [2], specifically: (a) control the output in a simple main window and test; (b) Observe the actual output waveform in a window similar to an oscilloscope; (c) Observe the harmonic content of the output waveform; (d) Generate complex output transients and their waveforms

Figure 2 voltage surge test

common AC power supply disturbances include: voltage surge, voltage sag, power failure, inrush current, etc. [3]. Use the established virtual test platform to test the voltage surge of a forward high-frequency switching power supply. The parameters of the voltage surge test are set as follows:

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