CN210720502U

CN210720502U - Electronic transformer acquisition equipment for realizing common power supply and common ground

Info

Publication number: CN210720502U
Application number: CN201921543960.7U
Authority: CN
Inventors: 辛明勇; 王宇; 孟令雯; 高吉普; 徐长宝; 吕黔苏; 张历; 祝健杨; 范强; 林呈辉; 汪明媚
Original assignee: Guizhou Power Grid Co Ltd
Current assignee: Guizhou Power Grid Co Ltd
Priority date: 2019-09-17
Filing date: 2019-09-17
Publication date: 2020-06-09
Anticipated expiration: 2029-09-17

Abstract

The utility model discloses a realize power altogether and electronic transformer collection equipment altogether, including analog circuit module, digital circuit module and power module, analog circuit module input connects the A looks, B looks and the C looks three routes signal of electronic transformer output, and the output is connected to the digital circuit module, and the digital circuit module passes through optic fibre and merges the unit equipment with signal transmission to the rear end, and power module provides the power for analog circuit module and digital circuit module respectively. The utility model has only one power supply module which respectively supplies power for the A, B, C three-phase sampling and signal processing circuit of the acquisition device, thereby effectively reducing the mutual interference and influence between different power supply modules, causing the instability of the power supply and causing the fluctuation and large distortion of the sampling data of the high-speed AD sampling circuit; meanwhile, both the analog loop and the digital loop of the acquisition device have only one grounding point, namely an analog ground and a digital ground, and the isolation of the analog ground and the digital ground is realized on a PCB (printed Circuit Board) board.

Description

Electronic transformer acquisition equipment for realizing common power supply and common ground

Technical Field

The utility model belongs to the technical field of intelligent substation electronic transformer acquisition unit, especially, relate to a realize common power and common ground electronic transformer collection equipment.

Background

At present, with the rapid development of intelligent substations, electronic transformers are widely applied in China. Compared with the traditional electromagnetic mutual inductor, the electronic mutual inductor has the advantages of small volume, light weight, no magnetic saturation, no secondary open circuit, capability of being conveniently combined and installed with primary high-voltage switch equipment, effective improvement on equipment integration level, land occupation reduction, convenience in installation and transportation and the like, and has wide market application prospect. With the further maturity of electronic transformer technology, it is a necessary trend to replace the traditional electromagnetic transformer.

However, since the electronic transformer is a transition body connecting a primary side strong current device and a secondary side weak current device in an intelligent substation, when a disconnecting switch and a circuit breaker in the substation are operated or the disconnecting switch and the circuit breaker have a ground fault, a strong interference signal is formed to affect an acquisition unit at the front end of the electronic transformer through a grounding network, a signal line and other ways, so that the acquisition unit is abnormal in operation, sampling distortion at the secondary side occurs, and stable operation of a protection device and the whole power system is affected. The anti-interference performance of the acquisition unit of the electronic transformer is mainly that whether the reliability of a power supply and the grounding of the acquisition unit are good or not is judged.

Disclosure of Invention

The to-be-solved technical problem of the utility model is: the utility model provides a realize electronic transformer collection equipment of sharing power and sharing ground to solve the independent design of electronic transformer collection unit three-phase (A looks, B looks, C looks) sampling module of prior art, shortcoming such as the heavy current of once side, strong voltage signal interference are easily received to independent power supply, independent ground connection's mode, to a great extent can influence the accuracy and the trouble incidence scheduling problem of electronic transformer collection unit sampling.

The utility model discloses the technical scheme who takes does: the utility model provides a realize electronic transformer collection equipment of power-sharing and ground-sharing, includes analog circuit module, digital circuit module and power module, and analog circuit module input connects the A looks, B looks and the C looks three routes signal of electronic transformer output, and the output is connected to the digital circuit module, and the digital circuit module passes through optic fibre with signal transmission to rear end merging cells equipment, and power module provides the power for analog circuit module and digital circuit module respectively.

The analog circuit module comprises three groups which are connected to the low-pass filter and the A/D conversion module in sequence.

The low-pass filter adopts a second-order passive low-pass filter, a resistance element in a filter loop adopts a non-inductive resistor with low temperature drift characteristic, and a capacitance device adopts ceramic capacitance with lower ESI and ESR values or CBB non-inductive capacitance.

The A/D conversion module adopts an AD7606 chip.

The digital circuit module adopts an FPGA digital signal processing module.

The power supply module comprises a main power supply module, the main power supply module is provided with two paths of outputs V1 and V2, the two paths of outputs V1 and V2 form an analog power supply system and a digital power supply system which supply power to the analog circuit module and the digital circuit module respectively through a power supply linear voltage stabilizing chip, the analog power supply system supplies power to the three-phase high-speed A/D conversion module and provides a reference voltage source, and the digital power supply system supplies power to the three-phase main control chip FPGA.

The power supply module also comprises a power supply monitoring module, and the power supply monitoring module is connected with the analog power supply system and the digital circuit module.

The utility model has the advantages that: compared with the prior art, the utility model has only one power supply module, which respectively supplies power for the A, B, C three-phase sampling and signal processing circuit of the acquisition device, thereby effectively reducing the mutual interference and influence between different power supply modules, causing the instability of the power supply and causing the fluctuation and large distortion of the sampling data of the high-speed AD sampling circuit; meanwhile, both the analog loop and the digital loop of the acquisition device are provided with only one grounding point, namely an analog ground and a digital ground, the isolation of the analog ground and the digital ground is realized on a PCB (printed Circuit Board), the grounding of the power module is directly connected with the shell through a grounding wire, and the shell is connected with a secondary ground of an application field when being installed outside, so that the whole acquisition device is grounded, and partial strong interference signals generated when the operation of a breaker, an isolating switch and a disconnecting link is carried out on a primary side in practical application are quickly released through grounding, thereby reducing the influence on a weak current loop inside the acquisition device.

Drawings

Fig. 1 is a schematic block diagram of the design of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

Example 1: as shown in fig. 1, an electronic transformer collecting device for realizing common power supply and common ground comprises an analog circuit module 1, a digital circuit module 2 and a power supply module 3, wherein the input end of the analog circuit module 1 is connected with three-way signals of a phase a, a phase B and a phase C output by the electronic transformer, the output end of the analog circuit module 1 is connected to the digital circuit module 2, the digital circuit module 2 transmits the signals to a rear merging unit device through optical fibers, the power supply module 3 respectively provides power for the analog circuit module 1 and the digital circuit module 2, and a shell of the collecting device is grounded.

A main power supply module in the power supply module is connected with an external power supply, realizes the conversion of the power supply and can complete two paths of output to respectively supply power to the analog signal processing module and the digital signal processing module; the analog signal processing circuit is mainly used for filtering A, B, C three-phase analog small signals output by the electronic transformer and carrying out A/D conversion processing; the digital signal processing circuit adopts the FPGA as a main control chip, realizes software integral reduction of differential output small signals of the electronic transformer and data communication protocol conversion, completes conversion from digital signals to optical signals, and finally outputs the signals through optical fibers.

The analog circuit block 1 comprises three groups connected in turn to a low-pass filter and an a/D conversion block.

The low-pass filter adopts a second-order passive low-pass filter, the 3dB bandwidth of the low-pass filter 4 is designed to be 1kHz, the cut-off frequency is 1kHz, the filtering effect of impurity interference signals in small input signals of the electronic transformer is achieved, a resistance element in a filtering loop adopts a non-inductive resistor with low temperature drift, a capacitance device adopts ceramic capacitance or CBB non-inductive capacitance with low ESI and ESR values, the filtering loop is ensured to have good enough high-frequency characteristics, and the cut-off frequency is designed to be 1 kHz.

The A/D conversion module adopts 2 AD to collect the input analog signal at the same time, and adopts an AD7606 chip, and the main characteristics of the AD7606 chip are as follows: true bipolar analog input range: 10V and 5V; 5V single analog power supply, VDRIVE: 2.3V-5V; the sampling precision of 16 bits is achieved, 8-channel synchronous sampling is supported, and the sampling frequency can reach 200kSPS at most; an input buffer with a built-in 2-order anti-aliasing analog filter and 1M omega analog input impedance; precise voltage and buffering in the chip. The power consumption is about 100mW, and can be as low as 25mW in standby; the sampling output can support high-speed serial and parallel interfaces, and the design adopts a serial output mode.

The digital circuit module 2 adopts an FPGA digital signal processing module and consists of three main control chips FPGA, software integration processing, an interpolation algorithm, system compensation coefficient adjustment and output protocol conversion are carried out on A, B, C three-phase digital input signals, conversion from the digital signals to optical signals is finally completed, the optical signals are sent to a merging unit at the rear end, the digital circuit module mainly uses FGPA as a main controller to carry out integration, interpolation, package and other processing on sampling data, meanwhile, data coding is carried out according to a transmission protocol, and the processed data are converted into optical signals to be output; the FGPA also monitors the state of the power supply of the AD acquisition module in real time through the power supply monitoring module, and realizes the real-time early warning function of the abnormal condition of the power supply, thereby quickly judging the validity and correctness of the AD sampling data. The main controller is realized by adopting XC3SD250E FPGA chip of Xilinx company. The working frequency of XC3SD250E can reach 200 Mhz; the number of logic gates is as high as 250k, a large number of on-chip memory units are provided, and only one PROM memory is needed externally to normally operate.

The power supply module 3 comprises a main power supply module 7, the main power supply module 7 is provided with two paths of outputs V1 and V2, the two paths of outputs V1 and V2 form an analog power supply system 8 and a digital power supply system 9 which supply power to the analog circuit module 1 and the digital circuit module 2 respectively through a power supply linear voltage stabilization chip, the analog power supply system 8 supplies power to the three-phase high-speed A/D conversion module 5 and provides a reference voltage source, the digital power supply system 9 supplies power to a three-phase main control chip FPGA, the power supply module can lead the three-phase analog loop of the acquisition device to realize a common analog grounding, the digital signal loop can also realize only one common digital grounding, the isolation between an analog ground and a digital ground is realized on a PCB, the power conversion efficiency is high, the size is small, the stability is high, the service life is long, and the high-grade EMS adaptability (IEC61000-4-5) and the common mode 6000 VAC) is high; the acceptable external power input range is AC 85-264V, DC85-370V, and the input frequency-DC/AC 47-60 Hz; the power supply module can realize multi-path output, thereby ensuring independent power supply of an analog power supply system and a digital power supply system, reducing mutual interference of the analog loop and the digital loop, and ensuring the reliability and the stability of the acquisition device, wherein V1 supplies power for the digital power supply system of the acquisition device, the output voltage of V1 is 5.2V, the output regulation rate is 5.1V-5.3V, the linear regulation rate is 5.1V-5.3V, the load regulation rate is 5.1V-5.3V, the current is 1.0A, and the ripple wave and the noise are p-75 mV; v2 is used for supplying power for the analog power supply system of the acquisition device, the output voltage is 5.0V, the output regulation rate is 4.8V-5.1V, the linear regulation rate is 4.8V-5.1V, the load regulation rate is 4.8V-5.1V, the current is 0.2A, and the ripple and noise p-150 mV; the power module also has the functions of overvoltage protection and overpower protection, and the overpower protection is carried out when the total output power is larger than 150% -230% of the rated output power, and the normal work is recovered after the fault is eliminated.

The power supply module 3 further comprises a power supply monitoring module 10, the power supply monitoring module 10 is connected with the analog power supply system 8 and the digital circuit module 2, real-time monitoring on the normal condition of the power supply of the AD conversion module 5 is achieved, once the power supply of the AD conversion module 5 is abnormally fluctuated and is lower than normal working voltage, the power supply monitoring module 10 sends an abnormal signal to the digital circuit module 2, and at the moment, the digital circuit module 2 judges the validity of sampling data.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention, therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. The utility model provides a realize electronic transformer collection equipment of sharing power and sharing ground which characterized in that: the power supply device comprises an analog circuit module (1), a digital circuit module (2) and a power supply module (3), wherein the input end of the analog circuit module (1) is connected with three-way signals of an A phase, a B phase and a C phase output by an electronic transformer, the output end of the analog circuit module is connected to the digital circuit module (2), the digital circuit module (2) transmits signals to rear-end merging unit equipment through optical fibers, and the power supply module (3) provides power for the analog circuit module (1) and the digital circuit module (2) respectively.

2. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 1, wherein: the analog circuit module (1) comprises three groups which are connected to the low-pass filter and the A/D conversion module in sequence.

3. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 1, wherein: the low-pass filter adopts a second-order passive low-pass filter.

4. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 1, wherein: the A/D conversion module adopts an AD7606 chip.

5. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 1, wherein: the digital circuit module (2) adopts an FPGA digital signal processing module.

6. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 1, wherein: the power supply module (3) comprises a main power supply module (7), the main power supply module (7) is provided with two paths of outputs V1 and V2, the two paths of outputs V1 and V2 form an analog power supply system (8) and a digital power supply system (9) which supply power to the analog circuit module (1) and the digital circuit module (2) respectively through a power supply linear voltage stabilization chip, the analog power supply system (8) supplies power and provides a reference voltage source for the three-phase high-speed A/D conversion module (5), and the digital power supply system (9) supplies power to a three-phase main control chip FPGA.

7. The acquisition equipment of the electronic transformer for realizing the common power supply and the common ground as claimed in claim 6, wherein: the power supply module (3) further comprises a power supply monitoring module (10), and the power supply monitoring module (10) is connected with the analog power supply system (8) and the digital circuit module (2).