CN103543353B - Direct current acquisition method under a kind of wide temperature environment - Google Patents

Abstract

The invention discloses the direct current acquisition method under a kind of wide temperature environment, do not increasing hardware cost, when still selecting non-wide temperature A/D sampler, image data and normal data are compared, obtain the virtual condition amount under current environmental temperature, improve accuracy transformer being carried out to status monitoring.Standard signal source refers to the physical quantity that respective sensor gathers, by testing standard signal source in advance, obtain the corresponding relation of temperature, accurately quantity of state, pre-acquired data, then the measurement data of reality is substituted in above-mentioned corresponding relation and compare, thus or quantity of state accurately, and this quantity of state is exported as reality.The present invention realizes the quantity of state collection to be measured under wide temperature environment on the basis of not updating the equipment, and reduces cost.

Description

Direct current acquisition method under a kind of wide temperature environment

Technical field

The invention belongs to power system transformer substation technical field of automation, relate to the direct current acquisition method under a kind of wide temperature environment, particularly relate to the method that transformer station process layer intelligent transformer terminal carries out High-accuracy direct current collection under wide temperature range.

Background technology

The transformer of 110kV and above thereof is the major equipment in electric system, is also the main node connecting each electrical network, once break down often cause large-area power-cuts.Undertaken accurately and timely detecting by the state such as winding temperature, the top-oil temperature etc. that run transformer body, analyze the operation conditions of transformer, operating exception can be found early, carry out preventive maintenance and maintenance targetedly, thus eliminate potential potential faults, effectively avoid unnecessary power failure, reduce transformer stop transport the repair time.

Intelligent transformer terminal is as the crucial IED of process layer in intelligent substation, monitoring backstage and the interfacing equipment between measure and control device and transformer body, need to carry out high-precision direct current collection to the quantity of state of transformer body, and after being converted to a sub-value directly or by process-level network based on the transformer substation case of GOOSE(towards general object, the abbreviation of GenericObjectOrientedSubstationEvent) service issues.

Traditional secondary device operating ambient temperature is-25 DEG C ~+55 DEG C, and intelligent transformer terminal is owing to being directly installed in transformer switch board, and operating ambient temperature can reach-40 DEG C ~+85 DEG C.Under such wide temperature range, affect by temperature drift, the numerical error that conventional method carries out direct current collection acquisition is comparatively large, can not meet the measuring accuracy required for status monitoring.

In addition, the device worked under wide temperature environment, due to the high temperature drift characteristic of device, can make the data collected have larger discreteness.But these discrete data accurately can not reflect the change of transformer state, and due to direct current gather passage more, direct current collection capacity quantity is more, if these data are sent to monitoring backstage and measure and control device by network, the burden of CPU and network can be increased the weight of, the fault diagnosis also easily making monitoring backstage do to make mistake and carry out ill-considered control command.

Summary of the invention

The object of this invention is to provide the direct current acquisition method under a kind of wide temperature environment, to solve the existing direct current acquisition method problem that numerical error is large, measuring accuracy is low under wide temperature environment.

In order to realize above object, the technical solution adopted in the present invention is: the direct current acquisition method under a kind of wide temperature environment, and the step of the method is as follows:

(1) quantity of state to be measured of Devices to test under current environmental temperature is gathered;

(2) image data and normal data are compared, obtain the virtual condition amount under current environmental temperature; Described normal data refers to: under this environment temperature, gather standard signal source, obtains pre-acquired data described in pre-acquired data, environment temperature, the described normal data of standard signal source correspondence formation.

Pre-acquired data in described normal data and standard value are subtracted each other, obtains modified value, each ambient temperature data in combined standard data, obtain a standard correction chart; Described standard value refers in normal temperature range the data that standard signal source collects.

Sampled data is carried out two stage filter process.

The process of described two stage filter is as follows: the mean value getting remainder data after all sampled datas are removed maximal value and minimum value; All sampled datas and the mean value obtained before are compared, removes the data exceeding this mean value setting range, then the data of remainder are averaged.

By the mode revising pre-acquired data in described standard correction chart, Configuration Online is carried out to normal data.

Change according to following formula the data in step (2) after comparison, obtain the actual measurement state magnitude of quantity of state to be measured, its formula adopted is as follows:

$U1=\frac{(U2-{\mathrm{Oup}}_{\min })\×({\mathrm{Inp}}_{\max }-{\mathrm{Inp}}_{\min })}{{\mathrm{Oup}}_{\max }-{\mathrm{Oup}}_{\min }}+{\mathrm{Inp}}_{\min }$

Wherein: U1---direct current output valve; U2---direct current input value;

Inp _min---input minimum value; Inp _max---input maximal value;

Oup _min---export minimum value; Oup _max---export maximal value.

The data once obtained through this step before data in step (2) after comparison and this acquisition channel are contrasted, if changing value is not greater than setting value, then think this sampling processing time this acquisition channel numerical value do not change, otherwise think that this acquisition channel numerical value there occurs sudden change; Adopt GOOSE message event transmission mechanism, when this acquisition channel numerical value does not change, repeat intervally to send by the very first time of setting; When numerical value is undergone mutation, enter bursty state, within second time interval, send multiframe continuously, and then send mode when getting back to steady state (SS), and very first time spacing value is greater than the second time interval value.

Direct current acquisition method under wide temperature environment of the present invention is under wide temperature working environment, do not increasing hardware cost, when still selecting non-wide temperature A/D sampler, image data and normal data are compared, to reach required high precision, obtain the virtual condition amount under current environmental temperature, improve accuracy transformer being carried out to status monitoring.Standard signal source refers to the physical quantity that respective sensor gathers, by testing standard signal source in advance, obtain the corresponding relation of temperature, accurately quantity of state, pre-acquired data, then the measurement data of reality is substituted in above-mentioned corresponding relation and compare, thus or quantity of state accurately, and this quantity of state is exported as reality.The present invention realizes the quantity of state collection to be measured under wide temperature environment on the basis of not updating the equipment, and reduces cost.

By carrying out two stage filter process to the data gathered, effectively can remove high frequency noise, obtaining the sampled value comparatively close with current data source.

In addition, by configuration tool, minimum value exported to the conversion of direct current collection, export maximal value, output quantity is selected, sudden change threshold, on send the cycle etc. to arrange, match with GOOSE service mechanism, make monitoring backstage can timing acquisition to current High-accuracy direct current image data, can upgrade with the fastest speed when image data is undergone mutation again.

Accompanying drawing explanation

Fig. 1 is system architecture schematic diagram of the present invention;

Fig. 2 is acquisition process process flow diagram of the present invention;

Fig. 3 is two stage filter process flow diagram of the present invention;

Fig. 4 is sampled value of the present invention conversion and decision flowchart;

Fig. 5 is the schematic diagram of GOOSE message event transmission mechanism of the present invention.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment, the present invention is described further.

Be illustrated in figure 1 the system architecture schematic diagram of the embodiment of the present invention, as seen from the figure, the intelligent transformer unit of this system carries out data transmission and communication by process-level network based on GOOSE message transmission mechanism and monitoring backstage and measure and control device.The signal input part of the A/D acquisition module of this intelligent transformer unit is connected with the signal output part of standard signal source and body sensors, the output terminal of A/D acquisition module is sent into two stage filter module and is processed after buffer memory is carried out in data buffer, data after filtering process transfer to the standard modified value correcting discrimination module and corresponding temperature and carry out peak clipping or compensation deals, finally data are transferred to monitoring backstage and measure and control device by GOOSE message sending module.In addition, this intelligent transformer unit be also provided with for undertaken by configuration tool pre-acquired data in correction mode setting and Standard modification correction chart Configuration Online control module.

Comparing traditional secondary equipment operating ambient temperature in the present embodiment is-25 DEG C ~+55 DEG C, and wide temperature operating ambient temperature range is-40 DEG C ~+85 DEG C.

As shown in Figure 2, it is as follows that the direct current acquisition method under wide temperature environment of the present invention comprises step:

(1) quantity of state to be measured of Devices to test under Current Temperatures is gathered;

(2) image data and normal data are compared, obtain the virtual condition amount under current environmental temperature; Described normal data refers to: under this environment temperature, gather standard signal source, obtains pre-acquired data described in pre-acquired data, environment temperature, the described normal data of standard signal source correspondence formation.

In the present embodiment, when carrying out data acquisition, every setting-up time, sampling should be carried out, carries out two stage filter process after continuous sampling set point number to sampled data; Its filtering is as follows: the mean value getting remainder data after all sampled datas are removed maximal value and minimum value; All sampled datas and the mean value obtained before are compared, removes the data exceeding this mean value setting range, then the data of remainder are averaged.

Pre-acquired data in described normal data and standard value are subtracted each other, obtains modified value, each ambient temperature data in combined standard data, obtain a standard correction chart; Described standard value refers in normal temperature range the data that standard signal source collects.Data after two stage filter process are contrasted with the modified value of corresponding Current Temperatures and revises, carry out peak clipping or compensation deals, to reach the high precision (the present embodiment gets 0.5%) of setting.

The standard correction chart of the present embodiment, as an independent configuration file, directly uses after can presetting in a program, also can carry out Configuration Online flexibly by the mode of amendment definite value, at utmost to improve the precision of direct current collection.The generative process of standard correction chart is as follows: under the different temperatures in wide temperature environmental field, direct current collection is carried out to a standard signal source, carry out check and correction by the data collected and standard value and obtain modified value, namely each temperature and the combination of corresponding modified value form standard correction chart.The standard signal source of the present embodiment refers to the physical quantity that respective sensor gathers.

Analyzed known by Fourier spectrum, the energy of sampled signal mainly concentrates on first-harmonic place, and in filtering process, the mean value getting certain limit can reach the object of filter away high frequency noise.In conjunction with the speed that frequency and the device CPU of DC quantity change in transformer station run, the present embodiment adopts the mode of sampling from whole second, sampling should be carried out for every 20ms, after continuous sampling 500 times, CPU performs a filtering algorithm, two stage filter all adopts extreme mean filter method, as shown in Figure 3, its process is as follows: the mean value getting remainder data after all sampled datas are removed maximal value and minimum value; All sampled datas and the mean value obtained before are compared, removes the data exceeding this mean value setting range (positive and negative 20%), then the data of remainder are averaged.Through two stage filter process, effectively can remove high frequency noise, obtain the sampled value comparatively close with current data source.

By configuration tool, minimum value exported to the conversion of direct current collection, export maximal value, output quantity is selected, sudden change threshold, on send the cycle etc. to arrange, the direct current collection value of output and the virtual condition of transformer can be made to agree with.Change according to following formula through the corrected data of contrast, obtain the actual measurement state magnitude of quantity of state to be measured, its formula is as follows:

$U1=\frac{(U2-{\mathrm{Oup}}_{\min })\×({\mathrm{Inp}}_{\max }-{\mathrm{Inp}}_{\min })}{{\mathrm{Oup}}_{\max }-{\mathrm{Oup}}_{\min }}+{\mathrm{Inp}}_{\min }$

Wherein: U1---direct current output valve; U2---direct current input value;

Inp _min---input minimum value; Inp _max---input maximal value;

Oup _min---export minimum value; Oup _max---export maximal value.

Winding temperature scope as body is-40 DEG C ~+85 DEG C, and that respective sensor exports is 4-20mA, and the 4-20mA data of acquisition are converted to the corresponding numerical value within the scope of-40 DEG C ~+85 DEG C by the output minimum value that can be arranged by reading and maximal value; And for example the ambient humidity of transformer is 0 ~ 100%, and what respective sensor exported is 0 ~ 5V signal, can say that output data are converted to the corresponding numerical value between 0 ~ 100%, is convenient to user like this and reads and analyze.

In addition, as shown in Figure 4 and Figure 5, in order to reduce the burden of CPU and network, the data once obtained through this step before the corrected data of contrast and this acquisition channel are contrasted, if changing value is not greater than setting value, then think this sampling processing time this acquisition channel numerical value do not change, otherwise think that this acquisition channel numerical value there occurs sudden change; Match with based on the GOOSE service mechanism issued and subscribe to, namely adopt GOOSE message event transmission mechanism (GOOSE message be meet DL/T860 substation communication network and system standard define in GOOSE message service format messages), when this acquisition channel numerical value does not change, repeat intervally to send by the very first time of setting; When numerical value is undergone mutation, enter bursty state, within second time interval, send multiframe continuously, and then send mode when getting back to steady state (SS), and very first time spacing value is greater than the second time interval value.Be illustrated in figure 5 the schematic diagram of GOOSE message event transmission mechanism of the present invention, the T0 in figure is the time interval retransmitted under stable condition (long-time without event); (T0) be the retransmission time interval under stable condition, when there is accident, this time likely shortens; T1 is after accident occurs, the shortest transmission time; T2 and T3 is the re-transmission time reaching stable condition.Adopt such transmission mode monitor backstage can timing acquisition to current High-accuracy direct current image data, can upgrade with the fastest speed when image data is undergone mutation again.

The application subsidizes by national high-tech research development plan (863 Program) problem, project number: 2012AA050206.

Claims (6)

1. the direct current acquisition method under wide temperature environment, it is characterized in that, the step of the method is as follows:

(1) quantity of state to be measured of Devices to test under current environmental temperature is gathered;

(2) image data and normal data are compared, obtain the virtual condition amount under current environmental temperature; Described normal data refers to: under this environment temperature, gather standard signal source, obtains pre-acquired data, and described pre-acquired data, environment temperature, standard signal source correspondence forms described normal data; The data once obtained through this step before data after comparison and this acquisition channel contrast, if changing value is not greater than setting value, then think this sampling processing time this acquisition channel numerical value do not change, otherwise think that this acquisition channel numerical value there occurs sudden change; Adopt GOOSE message event transmission mechanism, when this acquisition channel numerical value does not change, repeat intervally to send by the very first time of setting; When numerical value is undergone mutation, enter bursty state, within second time interval, send multiframe continuously, and then send mode when getting back to steady state (SS), and very first time spacing value is greater than the second time interval value.

2. the direct current acquisition method under wide temperature environment according to claim 1, it is characterized in that: the pre-acquired data in described normal data and standard value are subtracted each other, obtain modified value, each ambient temperature data in combined standard data, obtain a standard correction chart; Described standard value refers in normal temperature range the data that standard signal source collects.

3. the direct current acquisition method under wide temperature environment according to claim 1, is characterized in that: sampled data is carried out two stage filter process.

4. the direct current acquisition method under wide temperature environment according to claim 3, is characterized in that: the process of described two stage filter is as follows: the mean value getting remainder data after all sampled datas are removed maximal value and minimum value; All sampled datas and the mean value obtained before are compared, removes the data exceeding this mean value setting range, then the data of remainder are averaged.

5. the direct current acquisition method under wide temperature environment according to claim 2, is characterized in that: carry out Configuration Online by the mode revising pre-acquired data in described standard correction chart to normal data.

6. the direct current acquisition method under wide temperature environment according to claim 1, it is characterized in that: the data in step (2) after comparison are changed according to following formula, obtain the actual measurement state magnitude of quantity of state to be measured, its formula adopted is as follows:

Wherein: U1---direct current output valve; U2---direct current input value;

Inp _min---input minimum value;

Inp _max---input maximal value;

Oup _min---export minimum value;

Oup _max---export maximal value.