SBX-WXYH microcomputer harmonic elimination deviceDetailed product description：

1. Model Description of SBX-WXYH Microcomputer Harmonic Elimination Device

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3. Technical Instructions for SBX-WXYH Microcomputer Harmonic Elimination Device
(1) Working power supply: AC 80-250V, 50-60Hz or DC 80-250V, power consumption less than 15W
(2) Environmental temperature: -20 to+50 ℃;  
(3) Environmental humidity: not exceeding 90% RH
(4) Eliminating resonant frequencies: 17Hz (1/3 division), 25Hz (1/2 division), 50Hz (power frequency), 150Hz (3rd harmonic)

4. Device features
(1) Suitable for various voltage levels and resonant frequencies (1/3 division, 1/2 division, power frequency, 3rd harmonic) with a wide range of applications;  
(2) No need for tuning and debugging, automatically enters the running state after startup, with minimal maintenance;  
(3) Distinguishable between ferromagnetic resonance, overvoltage, and single-phase grounding;  
(4) Automatically display and record the occurrence time and related parameters (resonance frequency, amplitude) of ferromagnetic resonance;  
(5) Can store 20 sets of fault information for recall and display;  
(6) Configurable communication interface (RS232 or RS485);  
(7) Output in contact closure mode or voice alarm output;  

5. Working principle of the device
This device uses an 80C196 single-chip microcomputer as the core component to perform loop detection on PT open delta voltage (i.e. zero sequence voltage). Under normal operating conditions, if the voltage is less than 30V, the high-power harmonic elimination component (thyristor) inside the device is in a blocked state and has no impact on the system. When the voltage of the PT opening triangle is greater than 30V, it indicates that the system has malfunctioned. The device begins to collect data on the open delta voltage. By using digital signal processing techniques such as digital measurement, filtering, and amplification, the data is analyzed and calculated to determine the current fault state. If a certain frequency of ferromagnetic resonance occurs, the CPU immediately starts the harmonic elimination circuit (making the thyristor conductive) to quickly eliminate the ferromagnetic resonance under strong damping. After the elimination of ferromagnetic resonance, the CPU makes corresponding records, stores, and automatically alarms and displays relevant resonance information (including occurrence time, frequency, amplitude, etc.). If it is overvoltage or single-phase grounding, after the CPU makes a diagnosis, the device will display and alarm separately, and automatically record and store relevant fault information. Finally, the CPU returns to its initial state and continues to detect the open delta voltage.  

6. Software composition of SBX-WXYH microcomputer harmonic elimination device
This device uses 80C196 assembly language to develop software, which mainly consists of monitoring program, floating-point operation library, diagnostic software, harmonic elimination, recording and other parts. The real-time monitoring program completes tasks such as voltage detection, sampling, diagnosis, harmonic elimination, clock, keyboard commands, and display. The simple block diagram is shown in Figure 1:

7. Hardware composition of the device
(1) Power Supply: This device uses a high-frequency switching power supply, which has strong anti-interference ability and allows for a large range of input voltage fluctuations. The output voltage is DC+5V, ± 12V
(2) Host part:
(3) The command and control center CPU of this device adopts the latest 16 bit microcontroller 80C196, which has the characteristics of fast computing speed, strong control capability, and safe and reliable operation. And it is equipped with an internal monitoring timer, which can free the system from crashes caused by software failures at any time, providing a guarantee for long-term safe and reliable operation;  
(4) Program memory EPROM, used for storing instructions;  
(5) Data storage RAM, used to store data calculation results, recall content, etc;  
(6) Data acquisition part: Its function is to convert analog signals into digital signals for computer processing;  
(7) Display section: Used as a clock under normal system conditions, it can display relevant fault information when the system malfunctions;  
(8) Harmonic elimination control: Control the harmonic elimination circuit and activate high-power harmonic elimination components to quickly eliminate ferromagnetic resonances of various frequencies.   

8. Installation of SBX-WXYH microcomputer harmonic elimination device
This device is installed on the PK screen or in the terminal box, and each device can be connected to 1-4 sections of busbars according to the user's selection. The schematic diagram of the terminal wiring after the device is as follows:
(1) 1PT * "and" 1PT "are respectively connected to the same name and non same name terminals of the first section of the busbar open delta voltage," 2PT * "and" 2PT "are respectively connected to the same name and non same name terminals of the second section of the busbar open delta voltage, and so on;
(2) The "power input" terminal can be connected to AC power or DC power without polarity. Its voltage range is 80-250V;
(3) The "external alarm" terminal is connected to the external alarm signal, and when there is no fault, it is a pair of normally open contacts. Close when the fault occurs and delay for about 1 minute until the fault disappears. Its contact capacity is DC 220V 0.5A. If the user needs, it can also be changed to voice alarm output, but it needs to be specified before ordering.
(4) Remote control port output:
(I) The serial port RS422/485 is a dual function port. When using RS485, only TXD+and RXD+need to be short circuited, and TXD - and RDX - need to be short circuited;
(II) Switching output: When ferromagnetic resonance occurs, 1-4 PT correspond to 1-4 sections of the busbar, and an alarm signal is output in a closed contact manner with a capacity of DC 24V/5A. The internal wiring is as follows:

9. Instructions for use
(1) Power supply: The indicator light is on when the power supply is normal. Otherwise, it should be checked whether the power supply or insurance is burnt out.  
(2) Display section:
(I) The device enters the operating state immediately after being powered on, displaying the year, month, day, week, hour, minute, and second;  
(II) When a single-phase grounding fault occurs in the system (such as the first section of the busbar or its associated line experiencing a single-phase grounding fault at 08:50:35 on March 8, 2003, with an open delta voltage of 60V and a current duration of 1 hour 08:08 seconds), the LCD screen displays the following content:
On March 8, 2003, at 08:50:35, busbar I was grounded at a voltage of approximately 60V for a duration of 01:08:08. Display time until the fault disappears;  
(III) When the system experiences a resonance fault (such as the first section of the bus experiencing a 25Hz frequency at 8:46:06 on June 8, 2003)
When resonance occurs and the open triangle voltage is 70V, the LCD screen displays the following content:
On June 8, 2003 at 08:46:06, a 25Hz resonance occurred on busbar I, with an amplitude of approximately 70V. Display time until 1 minute after the fault disappears.  
(3) Button section
(I) "Reset" button: When the device malfunctions, please use the "Reset" button to restart the device;  
(II) "Remembrance" button: When a resonance fault occurs in the system, the screen will display the following prompt: "Please press the" Remembrance "button to view the fault information". At this time, pressing the "Remembrance" button can view the latest fault information. Continuing on time will result in a total of 20 resonance fault messages. The display form is the same as when resonance occurs;  
(III) "Timing" button: To adjust the year, month, day, week, and clock, press the "Timing" button. When the data to be adjusted flashes, press the "Plus One" or "Minus One" button. After adjustment, please continue to press the "time calibration" button until all data stops flashing, thus completing one time calibration process.  
10. Design specifications and ordering instructions
(1) The size of the opening on the screen of the chassis:
All models are 210 × 180 (width × height), and the depth of the chassis is 250mm
(2) The external dimensions of the chassis are as follows:
(3) Ordering precautions
If users need serial port function or language alarm function when ordering this product, please indicate it, otherwise it will be considered as not configured with the above functions. At the same time (refer to model 2 instructions), it is necessary to indicate the number of busbars carried.