CN103954865A - Mechanical-state on-line monitoring device of transformer winding - Google Patents

Abstract

The invention provides a mechanical-state on-line monitoring device of a transformer winding. The output end of an electricity quantity sensor is connected with a synchronous square wave conversion circuit and an anti-aliasing low-pass filter, and the anti-aliasing low-pass filter is connected with a control unit sequentially through an amplitude-limiting circuit and an A/D conversion circuit, the synchronous square wave conversion circuit is connected with the A/D conversion circuit sequentially through a zero cross detection circuit, a modified phase locking frequency multiplier circuit and a sampling control selection circuit; the control unit comprises a single-chip microcomputer unit and a digital signal processor, the single-chip microcomputer unit and the digital signal processor are connected through a double-port RAM, the digital signal processor carries out transformer short-circuit impedance calculation on electric parameter digital signals sent by the A/D conversion circuit, and the single-chip microcomputer unit stores and displays the data and sends the data to an electricity system monitoring platform. Compared with the prior art, the mechanical-state on-line monitoring device of the transformer winding can carry out real-time on-line monitoring on transformer short-circuit impedance, avoid a sudden breakdown of a transformer due to sudden mechanical faults, and largely improve the operation reliability of the transformer.

Description

A kind of Transformer Winding machine performance on-Line Monitor Device

Technical field

The present invention relates to a kind of transformer monitoring device, be specifically related to a kind of Transformer Winding machine performance on-Line Monitor Device.

Background technology

Power transformer is as one of most important hinge of electric system, and its safe operation is directly connected to the safety and reliability of generating and electric power system.If a large-scale power transformer has an accident in the time of generating and electric power system operation, may cause large-area power-cuts, have a strong impact on people's production, life.Wherein, the core component winding of power transformer is to cause power transformer one of the more parts that break down; therefore the winding deformation of power transformer is monitored; it is the important means that ensures the normal operation of power transformer; but in prior art, winding is monitored to common employing preventive trial; regular preventive trial can not be considered the actual operating state of power equipment, may occur too much maintenance and unnecessary shutdown, can not find in time again winding defect.

Power transformer is in operational process, and the variation of Transformer Winding is directly reacted in the variation of short-circuit reactance, the transformer mechanical fault that just can avoid winding deformation to cause by the reactance of monitoring transformer short-circuit.

Summary of the invention

In order to meet the needs of prior art, the invention provides a kind of Transformer Winding machine performance on-Line Monitor Device, described device comprises the electrical quantity sensor being connected with Transformer Winding, and the output terminal of described electrical quantity sensor is connected with anti-aliasing low-pass filter with zero cross detection circuit respectively; Described anti-aliasing low pass filter is connected with control module by amplitude limiter circuit, A/D change-over circuit successively; Described zero cross detection circuit selects circuit to be connected with described A/D change-over circuit by synchronous square wave translation circuit, improvement phase-locking frequency multiplication circuit, controlling of sampling successively; Described control module comprises the single machine unit and the digital signal processor that connect by dual port RAM;

The electric parameter digital signal of the Transformer Winding that described digital signal processor sends described A/D change-over circuit is carried out effective value, phase angle, active power, reactive power and Calculation of transformer short-circuit impedance, and result of calculation is stored in described dual port RAM;

Described single machine unit is carried out data Storage & Display to described effective value, phase angle, active power, reactive power and Transformer Short Circuit Impedance, and sends it to electric power supervisory control platform.

Preferably, described anti-aliasing low pass filter adopts second order sallen-key low-pass filter;

Preferably, described amplitude limiter circuit comprises the first amplifier and the second amplifier that reverse input end is connected; Between the output terminal of the output terminal of described the first amplifier and described the second amplifier, be connected in series two diodes; The reverse input end of the 3rd amplifier is directly connected with output terminal;

The in-phase input end of described the 3rd amplifier is connected with described anti-aliasing low pass filter; The output terminal of described the 3rd amplifier is connected with described A/D change-over circuit after being connected with the tie point of the inverting input of the first amplifier, described diode successively by resistance;

Preferably, described A/D change-over circuit comprises two ADS8364 chips that are connected in series, for realizing the synchrodata conversion of Shi Er road signal and the digital signal after conversion being sent to described digital signal processor;

Preferably, described single machine unit comprises a STM32 microprocessor and a liquid crystal display; Described dual port RAM adopts CY7C026 chip;

Preferably, the input end of described synchronous square wave translation circuit is connected with the inverting input of amplifier by resistance R 1, R2 successively; Described inverting input is connected with the output terminal of amplifier by resistance R 3, R4; The in-phase input end of described amplifier comprises three branch roads, and a branch road is connected with the output terminal of amplifier by resistance R 6, R4, and a branch road is by resistance R 5 ground connection, and a branch road is connected with the output terminal of amplifier by resistance R 7;

Preferably, described improvement phase-locking frequency multiplication circuit comprises phase-locked loop circuit sum counter; Described phase-locked loop circuit connects with the described square wave translation circuit of synchronizeing, and described counter selects circuit to be connected with described controlling of sampling;

Described phase-locked loop circuit adopts CD4046 chip; Described counter adopts CD4040 chip; Described controlling of sampling selects circuit to adopt CD4051B chip;

Preferably, described digital signal processor adopts least square method of recursion to obtain described Transformer Short Circuit Impedance.

Compared with immediate prior art, excellent effect of the present invention is:

1, in technical solution of the present invention, adopt least square method of recursion to carry out on-line identification to transformer short-circuit reactance in service, can find in time winding defect, overcome in prior art and regularly shut down and overhaul the inconvenience bringing;

2, in technical solution of the present invention, adopt the dual-cpu structure of DSP+STM32 microprocessor, effectively solve the problem of single microcontroller processing power deficiency and resource-constrained, can alleviate the contradiction of algorithm complexity and system real time requirement;

3, in technical solution of the present invention, the synchronous data collection mode that part of data acquisition has adopted frequency multiplication of phase locked loop circuit to combine with two AD acquisition chips, ensure real-time and the validity of image data, avoided, by software, the shortcoming that trigger pulse real-time cannot ensure is set;

4, a kind of Transformer Winding machine performance on-Line Monitor Device provided by the invention, can carry out on-line monitoring to transformer high-low-voltage side resistance and short-circuit reactance, and whether the foundation of mechanical deformation or fault occurs as winding by short-circuit reactance variable quantity.

Brief description of the drawings

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

Fig. 1 is: a kind of application connection layout of on-line monitoring device of transformer winding state in the embodiment of the present invention;

Fig. 2 is: Transformer Winding identification model sketch in the embodiment of the present invention;

Fig. 3 is: the three-phase double winding equivalent model sketch of transformer in the embodiment of the present invention;

Fig. 4 is: a kind of on-line monitoring device of transformer winding state structural drawing in the embodiment of the present invention;

Fig. 5 is: anti-aliasing low-pass filter circuit figure in the embodiment of the present invention;

Fig. 6 is: amplitude limiter circuit figure in the embodiment of the present invention;

Fig. 7 is: synchronous square wave translation circuit figure in the embodiment of the present invention;

Fig. 8 is: phase-locked loop circuit CD4046 chip internal structure figure in the embodiment of the present invention;

Fig. 9 is: in the embodiment of the present invention, improve phase-locking frequency multiplication circuit circuit diagram;

Figure 10 is: A/D conversion-control circuit figure in the embodiment of the present invention;

Figure 11 is: control module connection layout in the embodiment of the present invention;

Figure 12 is: OLED display module connection layout in the embodiment of the present invention.

Embodiment

Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Be exemplary below by the embodiment being described with reference to the drawings, be intended to for explaining the present invention, and can not be interpreted as limitation of the present invention.

A kind of Transformer Winding machine performance on-Line Monitor Device provided by the invention, is connected between transformer and the industrial computer of monitor supervision platform as shown in Figure 1, concrete structure as shown in Figure 4:

Described pick-up unit comprises electrical quantity sensor, synchronous square wave translation circuit, anti-aliasing low-pass filter, amplitude limiter circuit, A/D change-over circuit, control module, zero cross detection circuit, improvement phase-locking frequency multiplication circuit, controlling of sampling selection circuit.

Electrical quantity sensor is connected with zero cross detection circuit and anti-aliasing low-pass filter respectively:

1.: anti-aliasing low pass filter is connected with control module by amplitude limiter circuit, A/D change-over circuit successively;

2.: zero cross detection circuit selects circuit to be connected with A/D change-over circuit by synchronous square wave translation circuit, improvement phase-locking frequency multiplication circuit, controlling of sampling successively;

3.: control module comprises the single machine unit and the digital signal processor that connect by dual port RAM; Digital signal processor respectively with synchronize square wave translation circuit, controlling of sampling and select circuit to be connected;

4.: electrical quantity sensor comprises voltage sensor and current sensor, be respectively used to detect three-phase voltage and the three-phase current of Transformer Winding.

The electric parameter digital signal of the Transformer Winding that digital signal processor sends A/D change-over circuit is carried out effective value, phase angle, active power, reactive power and Calculation of transformer short-circuit impedance, and result of calculation is stored in dual port RAM; Single machine unit is carried out data Storage & Display to effective value, phase angle, active power, reactive power and Transformer Short Circuit Impedance, and send it in the industrial computer of electric power supervisory control platform, be convenient to monitor staff and carry out transformer winding state monitoring by the result of calculation of electric parameter.

In described monitoring device, the concrete structure of each several part circuit is:

(1) as shown in Figure 5, in the present embodiment, anti-aliasing low pass filter adopts second order sallen-key low-pass filter, comprises an operational amplifier, resistance R A, RB, R, mR, capacitor C, mC.

The in-phase input end of operational amplifier comprises two branch roads, and a branch road is connected with output terminal with electric capacity mC by resistance R, and another branch road is by capacitor C ground connection; The inverting input of operational amplifier also comprises two branch roads, and a branch road is connected with RB output by resistance, and another branch road is by resistance R A ground connection; Wherein the input end of anti-aliasing low pass filter is connected between resistance R and electric capacity mC by resistance mR.

In the present embodiment, second order sallen-key low-pass filter has larger quality factor, can obtain good accurate Gaussian waveform output with less active filter progression, has extraordinary signal filtering effect.

(2) as shown in Figure 6, in the present embodiment, amplitude limiter circuit comprises the first amplifier, the second amplifier, the 3rd amplifier, diode D1, D2, resistance R.

The first amplifier is directly connected with the inverting input of the second amplifier, and the output terminal of the first amplifier is connected with the output terminal of the second amplifier by diode D1, D2 successively; The reverse input end of the 3rd amplifier is directly connected with its output terminal;

The in-phase input end of the 3rd amplifier is connected with anti-aliasing low pass filter; The output terminal of the 3rd amplifier is connected with A/D change-over circuit after being connected with the tie point of the inverting input of the first amplifier, diode D1, D2 successively by resistance R.

In the present embodiment, amplitude limiter circuit can realize double limiting, guarantee A/D change-over circuit is avoided the Measurement accuracy of damage and monitoring device, overcome the traditional slicer that realizes amplitude limit function based on diode breakdown characteristic and existed the non-constant and not wield shortcoming of voltage stabilizing value, wherein set UR=± 2.5V, external high-precision reference level, the amplitude limit function of can realize ± 2.5V.

(3) as shown in Figure 7, in the present embodiment, synchronous square wave translation circuit comprises an operational amplifier, resistance R 1, R2, R3, R4, R5, R6, R7, diode D.

The in-phase input end of operational amplifier comprises three branch roads, and a branch road is connected with the output terminal of amplifier by resistance R 6, R4, and a branch road is by resistance R 5 ground connection, and a branch road is connected with the output terminal of amplifier by resistance R 7; The inverting input of operational amplifier comprises two branch roads, and a branch road is connected with the output terminal of amplifier by resistance R 3, R4, and another branch road is connected with resistance R 2, R1 successively, ground connection after wherein diode is connected between resistance R 2, R1.

Synchronous square wave translation circuit is taked the power supply mode of 3.3V single supply, makes the high level signal of its output 3.3V, to meet the level requirement of the circuit such as A/D change-over circuit and digital signal processor; Synchronous square wave translation circuit is used for:

1.: the square-wave signal of same phase is sent to the CAP trapping module of digital signal processor, to realize the measurement to power network signal frequency;

2.: the square-wave signal of same phase is sent in modified phase-locking frequency multiplication circuit, and modified phase-locking frequency multiplication circuit produces frequency doubling signals springs A/D change-over circuit based on described square-wave signal and carries out synchronous equal interval sampling.

(4) as shown in Figure 9, in the present embodiment, improve phase-locking frequency multiplication circuit and comprise phase-locked loop circuit CD4046 chip sum counter CD4040 chip; Phase-locked loop circuit CD4046 chip with synchronize square wave translation circuit and connect, counter CD4040 chip and controlling of sampling selection circuit CD4051B chip is connected;

The cut-away view of phase-locked loop circuit CD4046 chip as shown in Figure 8, comprise phase comparator (Phase Comparator, PC), low-pass filter (Low Pass Filter, and voltage controlled oscillator (Voltage Controlled Oscillator, VCO) LPF);

Improve phase locking frequency multiplying electric energy and enough ensure that digital signal processor avoids the interference of synchronized sampling, tracking sampling frequency in real time, reduces software work amount, improves reliability and the accuracy of synchronized sampling.

1.: phase-locked loop circuit CD4046 chip is a kind of universal CMOS phase-locked loop intergrated circuit, has the various features such as supply voltage wide ranges, input impedance is high, dynamic power consumption is little; Phase-locked loop circuit can carry out from motion tracking the output signal of zero cross detection circuit;

2.: counter CD4040 chip and controlling of sampling select circuit CD4051B chip for the frequency of sampled signal is set, and detailed process is:

In the time that phase-locked loop circuit CD4046 chip is in the lock state, the phaselocked loop frequency input signal of the output signal frequency of counter and CD4046 chip equates, can obtain frequency multiplication output signal f at the input end CLK of counter pin _o=N × f _i; If sampling 64 points in a fundamental frequency cycles, 64 frequencys multiplication that frequency of sampled signal is fundamental frequency, by the Q6 pin of CD4040 chip, sampling number being set is 64 points, and now the phaselocked loop input end pin of the Q6 pin of CD4040 chip and CD4046 chip is connected to form frequency multiplier circuit No. 64 times;

In the time receiving the instruction of amendment sampling number, STM32 microprocessor in control module is exported the three bit address codes of controlling controlling of sampling selection circuit CD4051B chip by I/O, carrying out corresponding passage switches, to realize different frequency dividing controls, obtain the output signal of different frequencys multiplication as the trigger pip of A/D change-over circuit, by the size of STM32 microprocessor amendment computing array, finally realize the real time modifying control function that synchronized sampling is counted simultaneously.By the improvement design of above phase-locking frequency multiplication circuit, make signal sampling mode more flexible, also make device there is better adaptability.

(5) as shown in figure 10, in the present embodiment, A/D change-over circuit comprises operational amplification circuit, level boostrap circuit, two ADS8364 chips; The differential input signal of the each passage of ADS8364 chip all needs to realize by operational amplifier and level boostrap circuit the signal that bipolarity AC signal is converted to 0～5V.Every ADS8364 chip can be realized the synchronous acquisition of six road signals, and therefore system has adopted two ADS8364 chips realize the synchrodata conversion of Shi Er road signal and the digital signal after conversion is sent to digital signal processor; In the present embodiment, digital signal processor adopts TMS320F28335 chip;

Wherein operational amplification circuit comprises CHA0+ concatenation operation amplifier and the periphery resistance circuit by output terminal and ADS8364 chip; Level boostrap circuit comprises the operational amplifier and the periphery resistance circuit that are connected with the REF_OUT of ADS8364 chip by in-phase input end.

The data reading manner of ADS8364 chip comprises first level address read mode, circulation read mode and FIFO read mode; In the present embodiment, monitoring device adopts first level address read mode.The chip selection signal CS of two ADS8364 chips is controlled by outside expansion mouthful CS_6AD, a CS_7AD respectively, and the address of data-switching result is mapped to respectively in the region 6 of digital signal processor TMS320F28335 chip and the scope in region 7.In the time that TMS320F28335 chip reads A/D data, address/mode select signal can be selected the mode of reading out data from ADS8364 chip.

ADS8364 chip tool has the following advantages:

1.: the synchronous switching rate of the highest 250ksps is provided, there is the conversion of six input channels of super low-power consumption (69mW/ passage), make the average cost per unit of each passage lower;

2.: the separate parallel processing speed that can improve hardware unit of hyperchannel;

3.: the fully differential input channel with the good common mode inhibition capacity of 80dB;

4.: data output interface can directly be connected with digital signal processor interface, saved middle level shifting circuit;

Together with its REF_IN being received with REF_OUT pin in the present embodiment, can provide for difference channel the reference voltage of 2.5V; Adopt single-ended input: general-IN termination common mode voltage 2.5V, the output of+IN termination front-end clipping circuit.

The maximum clock frequency of ADS8364 chip is 5MHz, provides by the PWM1 delivery outlet of MS320F28335 chip, and the ADD of ADS8364 chip and BYTE position are made as low level;

Improve the output signal of phase-locking frequency multiplication circuit as the trigger pip of A/D change-over circuit, wherein synchronizing frequency doubling signal HOLD is the trigger pip of three pairs of sample/hold amplifiers in ADS8364 chip, after every pair of Channel-shifted of ADS8364 chip completes, to send external interrupt request signal to the XINT1 of MS320F28335 chip by EOC mouth, after the request of MS320F28335 die response external interrupt, start and read A/D subroutine, by address wire gating respective channel, and A/D change-over circuit conversion gained digital quantity is read in by data line, be saved in array.

(6) as shown in FIG. 11 and 12, in the present embodiment, single machine unit is connected with digital signal processor by dual port RAM; Single machine unit comprises a STM32 microprocessor and a liquid crystal display; Wherein, dual port RAM adopts CY7C026 chip, and liquid crystal display is the VGY12864C display module of SSD1305OLED driver, and digital signal processor adopts TMS320F28335 chip.The interface mode of VGY12864C display module adopts Direct Access Mode, and STM32 microprocessor carries out concurrent access and control by peripheral hardware I/O mouth to VGY12864C display module.

1.: the control module in the present embodiment in monitoring device comprises the dual-cpu structure that single machine unit and digital signal processor form, not only can treatment cycle task, as data acquisition, analytical calculation etc., and sudden task, as man-machine interaction, data communication etc., can also ensure the real-time of monitoring device simultaneously.Wherein,

Digital signal processor is responsible for the tasks such as data acquisition, data operation and processing;

Single machine unit is responsible for storage, the man-machine interaction of data and is carried out the functions such as communication with monitor supervision platform industrial computer.

The Transformer Winding on-line monitoring method that adopts monitoring device provided by the invention to be combined with electric power supervisory control platform, can effectively solve the defect of single microcontroller undertreatment and resource-constrained, alleviate the contradictory problems of algorithm complexity with monitoring requirement of real-time, realized stable data processing and friendly man-machine monitoring interface.

Monitor supervision platform industrial computer is responsible for the real-time demonstration of carrying out subsequent treatment, data base administration, parametric line of the data that control module is uploaded, the transmission of downlink command, diagnosis, alarm prompt, failure message record and the inquiry of historical data etc. of transformer winding fault.

2.: TMS320F28335 chip and CY7C026 chip adopt direct connected mode; STM32 microprocessor is expanded and is connected by bus with CY7C026 chip, utilizes the latch function of latch, by enabling control, adopts the mode of I/O mouth time-sharing multiplex to realize the read-write of address and data.

When TMS320F28335 chip and STM32 microprocessor carry out exchanges data, produce conflict for avoiding that write operation is carried out in same address, the address space of CY7C026 chip is divided into two regions, distributing to respectively TMS320F28335 chip and STM32 microprocessor uses, the two can only carry out write operation in the space of distributing to oneself, in the other side region, carry out read operation, improve exchanges data reliability thereby avoid producing conflict.

3.: VGY12864C display module has the following advantages:

VGY12864C display module is OLED monochrome, character, the image display module of 128 row × 64 row dot matrix; Compared with traditional LC D display module, OLED adopts 3.3V low-work voltage, can self to be luminous, and brightness is high, and high-contrast does not need backlight, and power consumption is lower; Ambient temperature range is wider-40～+ 85 DEG C; Visual perspective is wider reaches 165 °; Response speed is faster, and profile is thinner, utilizes OLED display module to promote the display capabilities on the spot of the disclosed monitoring device of the present embodiment, has also expanded its applied environment scope.

4.: single machine unit is connected and is connected the problem that has solved mass data exchange between digital signal processor and single machine unit with digital signal processor by dual port RAM, has improved efficiency and the reliability of data communication and resource sharing;

Control module according to requirement of actual working condition select Rs-485 bus, GPRS is wireless or Ethernet mode is communicated by letter with monitor supervision platform industrial computer.

(7), while Transformer Winding machine performance on-Line Monitor Device provided by the invention being carried out to industrial implementation, should take following measure:

1.: isolation and shield measure;

Input, output circuit are effectively isolated by photo-coupler; In secondary circuit when wiring, by strong, weak electricity signal wire is separately realized isolation, has avoided between loop, interacting and disturbing mutually impact, the wiring of printed circuit board (PCB) by signal wire and power lead separate, digital circuit separates with mimic channel, the isolation effect of guarantee circuit;

2.: monitoring device modular design measure;

The mode of utilizing plate to connect realizes the flexible configuration of each module in monitoring device and selects, select circuit to be connected by middle connecting plate unit electrical quantity sensor, synchronous square wave translation circuit, anti-aliasing low-pass filter, amplitude limiter circuit, A/D change-over circuit, control module, zero cross detection circuit, improvement phase-locking frequency multiplication circuit and controlling of sampling, make full use of space and make monitoring device more compact structure, each module is relatively independent to be connected each other again, be convenient to the renewal of expansion and module, phase mutual interference between isolation module, the reliability of raising monitoring device;

3.: the treatment measures of power circuit;

Between the positive and negative electrode of power circuit and connect jumbo electric capacity; Between the VDD-to-VSS of the each module chips of monitoring device, be provided with decoupling capacitance; Wherein, reduce the distributed capacitance between power lead and monitoring device shell thereby zero-power line floats sky as far as possible, avoid interference.

The course of work that described monitoring device carries out on-line monitoring to Transformer Winding machine performance is:

One, part of data acquisition:

(1) monitoring device electrification reset initialization, comprise, the initialization of the inner various control registers of control module, initialization, the initialization of correlated variables etc. of data buffer, complete the setting of low speed and high-speed peripheral clock frequency, setting, the setting of communication mode and the parameter initial value of each software module of I/O equipment arranges etc., for the data acquisition and processing (DAP) of monitoring device is got ready;

(2) control module calls PWM initialize routine, sets cycle and the dutycycle of PWM, input clock divider ratio, the cycle etc. of base T when capturing unit CAP is set, and start corresponding timer conter; PIE is interrupted in initialization peripheral hardware expansion, external interrupt XINT1, capture interrupt CAP1 that the program that enables is used, serial ports interruptions, timer interruption etc., clear corresponding interrupt flag bit, startup global interrupt;

(3) A/D change-over circuit is resetted and initialization; The response of wait external interrupt, in the time having external interrupt trigger pip, reads transformation result by data bus, completes the data sampling of a cycle signal.

Two, data processing section:

(1) A/D change-over circuit completes data-switching one time, sends a pulse signal to the external interrupt mouth of digital signal processor;

(2) digital signal processor response external is interrupted, and reads the A/D data-switching result in the storage area address of each passage mapping by data bus;

(3) digital signal processor completes calculating voltage effective value after the sampling of a cycle signal, current effective value, current and phase difference, voltage phase difference, active power, reactive power and Transformer Short Circuit Impedance, and result of calculation is stored in dual port RAM; Single machine unit reads, stores, shows the data in dual port RAM, and sends it in the industrial computer of electric power supervisory control platform, is convenient to monitor staff and carries out transformer winding state monitoring by the result of calculation of electric parameter.

Digital signal processor adopts least square method of recursion to obtain described Transformer Short Circuit Impedance:

One, the principle of work of least square method of recursion is:

Suppose a two-port linear system y=p ₁θ ₁+ p ₂θ ₂+ ...+p _nθ _n, y is output variable, P=(p ₁, p ₂..., p _n) be input variable, intermediate parameters collection θ=(θ ₁, θ ₂..., θ _n) be a unknown constant collection; At t ₁, t ₂..., t _nmoment is introduced vector matrix Y and Φ, and the Y measuring can use y (i) to represent, P can use p ₁(i), p ₂(i) ..., p _n(i), i=1,2 ..., m represents;

Therefore above-mentioned two-port linear system is: y (i)=θ ₁p ₁(i)+θ ₂p ₂(i)+...+θ _np _n(i), i=1,2 ..., m, wherein,

$\mathrm{\Φ}=\left[\begin{array}{cccc}{p}_1\left(1\right)& p_2\left(1\right)& \·\·\·& p_n\left(1\right)\\ p_1\left(2\right)& p_2\left(2\right)& \·\·\·& p_n\left(2\right)\\ & \·& & \\ & \·& & \\ & \·& & \\ p_1\left(m\right)& p_2\left(m\right)& & p_m\left(m\right)\end{array}\right];$ Y＝[y(1),y(2),...,y(m)] ^T；θ＝[θ ₁,θ ₂,...,θ _n] ^T；

Be Y=Φ θ; Wherein, Y is output variable matrix; Φ is input variable matrix; θ is parameter matrix to be identified.

Real-time and the computational accuracy of monitoring device disclosed by the invention to data had relatively high expectations, and therefore, in the time of the newly-increased sampled data of monitoring device, only original vector to be identified carried out to part correction.The Recursive Identification Procedures of corresponding least square method of recursion is as follows:

Step 1: obtain parameter measurement equation to be identified: $\widehat{\mathrm{\θ}}(k+1)=\widehat{\mathrm{\θ}}\left(k\right)+K(k+1)[y(k+1)-h^T(k+1)\widehat{\mathrm{\θ}}\left(k\right)];$

Step 2: obtain gain matrix: K (k+1)=P (k) h (k+1) [h ^t(k+1) P (k) h (k+1)+1] ^-1;

Step 3: obtain error covariance matrix: P (k+1)=[I-K (k+1) h ^t(k+1)] P (k);

Wherein, y (k+1) is the sampled value in k+1 moment, the parameter value to be identified in moment, I is unit matrix; The data of output matrix y and input matrix h can obtain by measurement.

Step 4: choose matrix P and θ initial value, comprising:

1.: observed reading method; By a collection of measured value, obtain the initial value of P and θ by nonrecursion least square method, require measurement data number N to be greater than 2n, n is the exponent number for the treatment of examining system, now P (N ₀)=[Φ ^t(N ₀) Φ (N ₀)] ^-1, then adopt Recursive Least Squares since (N+1) individual data;

2.: directly setting method; By the artificial selected initial value that calculates, as θ (N ₀)=0, P (N ₀)=I/ ε, ε takes fully enough little, after calculating, can obtain suitable result, and then carry out Recursive Least Squares calculating by certain number of times recursion.

Two, the step that in the present embodiment, digital signal processor adopts least square method of recursion to obtain Transformer Short Circuit Impedance is:

As illustrated in fig. 1 and 2, in the present embodiment, set up equivalent model as an example of three-phase two-simulation transformer example, wherein i _a, i _b, i _cand i _a, i _b, i _cbe respectively each phase current of transformer both sides winding;

Step 1: obtain the kirchhoff voltage equation in each winding circuit loop in voltage device, comprising:

$\left\{\begin{array}{c}{u}_A=i_A{R}_A+L_A\frac{{\mathrm{di}}_A}{\mathrm{dt}}+N_1\frac{d{\mathrm{\φ}}_a}{\mathrm{dt}}\\ u_B=i_B{R}_B+L_B\frac{{\mathrm{di}}_B}{\mathrm{dt}}+N_1\frac{d{\mathrm{\φ}}_b}{\mathrm{dt}}\\ u_C=i_C{R}_C+L_C\frac{{\mathrm{di}}_C}{\mathrm{dt}}+N_1\frac{{\mathrm{d\φ}}_c}{\mathrm{dt}}\end{array}\right.,\left\{\begin{array}{c}{u}_a=i_a{R}_a+L_a\frac{{\mathrm{di}}_a}{\mathrm{dt}}+N_2\frac{{\mathrm{d\φ}}_a}{\mathrm{dt}}\\ u_b=i_b{R}_b+L_b\frac{{\mathrm{di}}_b}{\mathrm{dt}}+N_2\frac{d{\mathrm{\φ}}_b}{\mathrm{dt}}\\ u_c=i_c{R}_c+L_c\frac{{\mathrm{di}}_c}{\mathrm{dt}}+N_2\frac{{\mathrm{d\φ}}_2}{\mathrm{dt}}\end{array}\right.;$

Wherein, u _a, u _b, u _cand u _a, u _b, u _cbe respectively each phase voltage of transformer both sides winding; R _a, R _b, R _cand R _a, R _b, R _cbe respectively the resistance of the each phase of former and deputy limit winding; L _a, L _b, L _cand L _a, L _b, L _cbe respectively the leakage inductance of the each phase of former and deputy limit winding; N ₁, N ₂be respectively the number of turn of former and deputy limit winding; φ _a, φ _b, φ _cbe respectively the public magnetic flux between each phase winding.

Step 2: system of equations in step 1 is merged to the public magnetic flux part of removing each phase, three-phase loop equation can be expressed as Unified Form after arranging: $u_1-N_T{u}_2=i_1{R}_1+L_{1\mathrm{\σ}}\frac{{\mathrm{di}}_1}{\mathrm{dt}}-N_T{i}_2{R}_2-N_T{L}_{2\mathrm{\σ}}\frac{{\mathrm{di}}_2}{\mathrm{dt}};$

Wherein, u ₁, u ₂for the voltage of transformer both sides winding; i ₁, i ₂for the electric current of transformer both sides winding; R ₁, R ₂for the resistance of transformer both sides winding; L _{1 σ}, L _{2 σ}for the leakage inductance of transformer both sides winding; N _t=N ₁/ N ₂, be the turn ratio of transformer both sides winding; Each phase voltage, the electric current of former and deputy limit winding are all directly gathered and obtain by monitoring device, and winding resistance, leakage inductance, turn ratio are parameter to be identified.

Step 3: by equation $u_1-N_T{u}_2=i_1{R}_1+L_{1\mathrm{\σ}}\frac{{\mathrm{di}}_1}{\mathrm{dt}}-N_T{i}_2{R}_2-N_T{L}_{2\mathrm{\σ}}\frac{{\mathrm{di}}_2}{\mathrm{dt}},$ Carry out discretize processing, can obtain

$\begin{array}{c}[\frac{u_1(n+1)+u_1\left(n\right)}{2}-N_T\frac{u_2(n+1)+u_2\left(n\right)}{2}]=\\ [\frac{i_1(n+1)+i_1\left(n\right)}{2}{R}_1+N_T\frac{i_2(n+1)+i_2\left(n\right)}{2}{R}_2]+L_{1\mathrm{\σ}}\left[\frac{i_1(n+1)-i_1\left(n\right)}{\mathrm{\ΔT}}\right]+N_T{L}_{2\mathrm{\σ}}\left[\frac{i_2(n+1)-i_2\left(n\right)}{\mathrm{\ΔT}}\right]\end{array}$

Equation left side voltage measures series and is set as output matrix Y, the current measurement series on its right is set as to input matrix Φ, with θ=[R ₁, L _{1 σ}, R ₂, L _{2 σ}, N _t] ^tfor parameter to be identified, adopt resistance, leakage inductance and the transformer voltage ratio of the principle of work calculating transformer winding of above-mentioned least square method of recursion; Finally by the short-circuit impedance of the each phase winding of leakage inductance calculation transformer.

Finally should be noted that: described embodiment is only some embodiments of the present application, instead of whole embodiment.Based on the embodiment in the application, those of ordinary skill in the art are not making the every other embodiment obtaining under creative work prerequisite, all belong to the scope of the application's protection.

Claims (8)

1. a Transformer Winding machine performance on-Line Monitor Device, described device comprises the electrical quantity sensor being connected with Transformer Winding, it is characterized in that, the output terminal of described electrical quantity sensor is connected with anti-aliasing low-pass filter with zero cross detection circuit respectively; Described anti-aliasing low pass filter is connected with control module by amplitude limiter circuit, A/D change-over circuit successively; Described zero cross detection circuit selects circuit to be connected with described A/D change-over circuit by synchronous square wave translation circuit, improvement phase-locking frequency multiplication circuit, controlling of sampling successively; Described control module comprises the single machine unit and the digital signal processor that connect by dual port RAM;

The electric parameter digital signal of the Transformer Winding that described digital signal processor sends described A/D change-over circuit is carried out effective value, phase angle, active power, reactive power and Calculation of transformer short-circuit impedance, and result of calculation is stored in described dual port RAM;

Described single machine unit is carried out data Storage & Display to described effective value, phase angle, active power, reactive power and Transformer Short Circuit Impedance, and sends it to electric power supervisory control platform.

2. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, described anti-aliasing low pass filter adopts second order sallen-key low-pass filter.

3. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, described amplitude limiter circuit comprises the first amplifier and the second amplifier that reverse input end is connected; Between the output terminal of the output terminal of described the first amplifier and described the second amplifier, be connected in series two diodes; The reverse input end of the 3rd amplifier is directly connected with output terminal;

The in-phase input end of described the 3rd amplifier is connected with described anti-aliasing low pass filter; The output terminal of described the 3rd amplifier is connected with described A/D change-over circuit after being connected with the tie point of the inverting input of the first amplifier, described diode successively by resistance.

4. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, it is characterized in that, described A/D change-over circuit comprises two ADS8364 chips that are connected in series, for realizing the synchrodata conversion of Shi Er road signal and the digital signal after conversion being sent to described digital signal processor.

5. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, described single machine unit comprises a STM32 microprocessor and a liquid crystal display; Described dual port RAM adopts CY7C026 chip.

6. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, the input end of described synchronous square wave translation circuit is connected with the inverting input of amplifier by resistance R 1, R2 successively; Described inverting input is connected with the output terminal of amplifier by resistance R 3, R4; The in-phase input end of described amplifier comprises three branch roads, and a branch road is connected with the output terminal of amplifier by resistance R 6, R4, and a branch road is by resistance R 5 ground connection, and a branch road is connected with the output terminal of amplifier by resistance R 7.

7. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, described improvement phase-locking frequency multiplication circuit comprises phase-locked loop circuit sum counter; Described phase-locked loop circuit connects with the described square wave translation circuit of synchronizeing, and described counter selects circuit to be connected with described controlling of sampling;

Described phase-locked loop circuit adopts CD4046 chip; Described counter adopts CD4040 chip; Described controlling of sampling selects circuit to adopt CD4051B chip.

8. a kind of Transformer Winding machine performance on-Line Monitor Device as claimed in claim 1, is characterized in that, described digital signal processor adopts least square method of recursion to obtain described Transformer Short Circuit Impedance.