CN203561629U - Online gas monitor for transformer - Google Patents

Abstract

The utility model provides an online gas monitor for a transformer. The online gas monitor comprises a monitoring circuit, wherein a signal acquisition unit, an external EEPROM (Erasable Programmable Read-Only Memory) unit, a clock circuit, a display unit and an interface circuit in the monitoring circuit are respectively connected with a microprocessor ATmega32; the microprocessor is connected with an upper computer by a communication unit circuit; the interface circuit comprises a keyboard interface and an alarming interface composed of an indication lamp and a buzzer; the external EEPROM unit is AT24C512; the clock circuit adopts a DS1302 chip; the signal acquisition unit comprises a TGS813 gas sensor and is used for acquiring a gas concentration signal, a temperature signal of the gas sensor and a temperature signal of a heater and then transmitting the signals to an AD (Analogue/Digital) converter in the microprocessor; the display unit is an LCM12832ZK liquid crystal display and is in serial communication with an I/O (Input/Output) port of the microprocessor; the communication unit circuit is in communication with the upper computer by an RS-485 serial port. The quantity of the chips is reduced; the size of the circuit board and the collection line of all the modules are good for realizing the automation of a control system and the optimization of the operation of an electric system.

Description

Transformer gas on-line monitor

Technical field

The utility model relates to a kind of monitoring device, especially transformer gas on-line monitor.

Background technology

Along with the development of modern technologies and social progress, what electric system also became becomes increasingly complex, also more and more higher to the requirement of electric system, thus, also more and more harsher to the requirement of protecting electrical power system.Transformer, as one of power equipment important in electric system, also causes that to its protection people more and more pay attention to, and the monitoring of Gas in Oil of Transformer is exactly wherein one.Through development for many years, the monitoring of gas in oil is developed into modern online monitoring from the monitoring of traditional off-line type, it is applied to and in production, has obtained certain achievement.The running status of transformer can be divided into normal condition and abnomal condition.Normal condition just refer to transformer usually, running status safely, abnomal condition refers to that transformer is owing to having potential faults or have fault and can not move normally, safely or state out of service.Many faults of transformer or potential faults can be by the reacting condition of the composition of gas in oil and the content of various compositions out.As can be seen here, Gas in Oil of Transformer is monitored, and according to the result of monitoring, to arrange transformer and electric system reasonably to move or overhaul be one of the important measures that improve power supply reliability, security and economy.Application to some extent of the on-Line Monitor Device of transformer in power industry.It seems at present, mostly these equipment are only for gas in oil, to carry out initial analysis, and to other state and fault, as the faults such as local pyrexia, multipoint earthing, shelf depreciation can not realize Real-Time Monitoring, say nothing of relevant operational factor is adjusted in real time.

Utility model content

The technical matters that the application will solve is to overcome above-mentioned defect, and a kind of transformer gas on-line monitor is provided.

For solving the problems of the technologies described above, the technical scheme of employing is:

Transformer gas on-line monitor, comprise observation circuit, signal gathering unit in observation circuit, outside EEPROM unit, clock circuit, display unit, interface circuit connect respectively microprocessor ATmega32, and microprocessor connects host computer by communication unit circuit; The remote alarm interface that interface circuit comprises keyboard interface, is comprised of pilot lamp and hummer, outside EEPROM is AT24C512, clock circuit adopts DS1302 chip, signal gathering unit comprises TGS813 gas sensor, for after gathering gas concentration signal, gas sensor temperature signal and heter temperature signal, be sent in the AD converter of microprocessor, display unit is LCMl2832ZK liquid crystal display, and carry out serial communication with the I/O mouth of microprocessor, between communication unit circuit and host computer, adopt RS-485 serial communication.

The beneficial effects of the utility model are: reduced number of chips, reduced again the on line between volume and each module of circuit board.For the design of circuit board and the anti-interference of device, there is great meaning.Utilize the communication module in Atmega32, can realize very easily the communication between other control device or upper level control device, be conducive to realize networking, the robotization of control system and the optimization of Operation of Electric Systems of whole protection system.

Accompanying drawing explanation

Fig. 1 is the circuit structure diagram of this gas on-line monitor.

Embodiment

Transformer gas on-line monitor comprises and comprises observation circuit, has with lower unit: the collecting unit (non-electrical signal becomes electric signal) of (1) gas concentration signal, gas sensor temperature signal, heter temperature signal; (2) microprocessor unit (other unit is processed and controlled to the signal collecting normally works); (3) outside EEPROM and clock circuit unit; (4) display unit (showing concentration value, rate of change, time and the temperature etc. of gas); (5) interface circuit unit: mainly comprise keyboard interface, remote alarm interface.Keyboard is input information interface, and this is essential in whole system.Remote alarm interface also has great role, although there has been Liquid Crystal Module, can show a lot of information, but suitably increases some pilot lamp hummers, can find out easily some important states of equipment; (6) communication unit (with other monitor carry out communication or with the communication of upper level pulpit).

In this device, the Atmega32 in the selected AVR single-chip microcomputer of microprocessor (MPU).Atmega32 is 8 AVR microprocessors of a high-performance, low-power consumption.It has the function of traditional micro-control unit (MCU), simultaneously its integrated again many peripheral module.The peripheral hardware that this device is used comprises: 40 I/O pins, and 8 10, tunnel analog to digital converters (ADC),

Can work in the SPI serial line interface of main frame/slave mode and I2C Bus interface etc.In this device, need to preserve a large amount of data and the memory capacity of microprocessor Atmega32 is limited, so be equipped with outside EEPROM to microprocessor, selected chip is 64K electricity erasable memorizer AT24C512.。Between DS1302 and single-chip microcomputer, can adopt simply the mode of synchronous serial to communicate and only need to use three mouth lines: (1) RES(resets) (2) I/O(data line) (3) SCLK (serial clock).The effect of signal gathering unit is adopted outer signals in Atmega32 exactly, and changes into data that Atmega32 can identify and put into temporary storage location and offer for display unit or communication unit.The core parts of signal gathering unit are sensors, and its effect is exactly that the non-electric charge quantity signalling (gas concentration value (ppm)) of input is converted to corresponding with it electric signal (1～5 volt of direct current), and it is first unit of whole device.Its work range and operating accuracy are directly connected to working range and the precision of whole device.During the working sensor of this device, except work measurement is with power supply, also need heating power supply.The operating voltage of this device and heating voltage are all 5V.The concentration signal of gas, gas sensor temperature signal, heter temperature signal are converted to after electric signal, are fed in the AD module of Atmega32.This installs selected sensor is the TGS813 gas sensor that Japanese Figaro company produces, and it is low to the sensitivity of noise gas, is mainly used in measuring the inflammable gass such as methane, propane, butane and hydrogen.Due to the structural reason of sensor itself, it is the result of the comprehensive response to various gas ingredients to the response results of gas.The concentration signal of gas becomes after electric signal in sensor, and the first via entering by the PA0 mouth of ATmega32 in analog to digital conversion (AD) module of ATmega32 through 240 Europe resistance is changed, and its transformation result is put into ADC

In data register (ADCL and ADCH).Sensor in gas sensor temperature signal collection circuit adopts three-wire system temperature compensation connected mode, via the Differential input circuit of amplifier interface chip composition, the temperature signal value collecting is met to mould/number conversion interface PA1 (ADC1) of Atmega32, the data acquisition of realization to temperature, heter temperature signal acquisition circuit has adopted the same design with gas sensor temperature signal collection circuit, just the temperature signal value collecting is received to mould/number conversion interface PA2 (ADC2) of Atmega32.The display unit of this device uses the I/O of Atmega32 directly to carry out serial communication with peripheral display, and display is selected LCMl2832ZK character mode lcd.Select four to touch composition keyboard, use independent keystroke interface.These four buttons are upper and lower, ESC and SET.No matter be the data communication of microprocessor and peripheral hardware or the communication of whole device and host computer, use be all serial port.The data communication side of microprocessor and peripheral hardware one is used SPI serial ports another is to use I2C serial ports.The communication of whole device and host computer adopts RS-485 communication network.

Claims (1)

1. transformer gas on-line monitor, it is characterized in that: comprise observation circuit, signal gathering unit in observation circuit, outside EEPROM unit, clock circuit, display unit, interface circuit connect respectively microprocessor ATmega32, and microprocessor connects host computer by communication unit circuit; The remote alarm interface that interface circuit comprises keyboard interface, is comprised of pilot lamp and hummer, outside EEPROM is AT24C512, clock circuit adopts DS1302 chip, signal gathering unit comprises TGS813 gas sensor, for after gathering gas concentration signal, gas sensor temperature signal and heter temperature signal, be sent in the AD converter of microprocessor, display unit is LCMl2832ZK liquid crystal display, and carry out serial communication with the I/O mouth of microprocessor, between communication unit circuit and host computer, adopt RS-485 serial communication.

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