CN106019101A - Electric power equipment insulation state evaluation method - Google Patents

Abstract

The invention discloses an electric power equipment insulation state evaluation method, solves disadvantages of two measurement methods in the prior art and aims to realize a portable insulation state assessment measurement device. According to the method, insulation aging state characteristic parameters of electric power equipment can be accurately detected, an insulation aging state of the electric power equipment is comprehensively evaluated, and great importance is realized for stable and reliable operation of the electric power grid.

Description

A kind of Electric Power Equipment Insulation state evaluating method

Technical field

The present invention relates to a kind of Electric Power Equipment Insulation state evaluating method.

Background technology

The present invention proposes portable Condition assessment of insulation system and method and mainly solves in-site measurement during current dielectric loss measurement and measure and anti-interference cause that dielectric loss measurement is unstable, high pressure equipment is inaccurate in small voltage test condition dielectric loss and garton effect is to problems such as high pressure equipment dielectric loss measurement are inaccurate.

Current metering system is such as: 1, Schering bridge method, owing to it draws mutual inductance and CT error is uncertain in measurement process, causes dielectric loss measurement result uncertain.2, self-balancing bridge method, due to its uncertain frequency influence by input measurement signal during measuring, thus causes the measured value of the test frequency instability of instability.

Summary of the invention

The technical problem to be solved is, not enough for prior art, it is provided that a kind of Electric Power Equipment Insulation state evaluating method.

For solving above-mentioned technical problem, the technical solution adopted in the present invention is: a kind of Electric Power Equipment Insulation state evaluating method, comprises the following steps:

1) Initialize installation noise and interference probe, is individually positioned in noise and interference probe on power frequency component suppression module, boost power factor adjustment module, buck power factor adjustment module, AC harmonic suppression module, standard and product to be tested；

2) noise and interferometry probe are started, read t noise and interference probe A, signal Ia (t) of B, C, D, E, Ib (t), Ic (t), Id (t), Ie (t), Temp (t), Hum (t), wherein t is noise and disturbs the probe sampling time, and Temp (t) and Hum (t) is t temperature, humidity reading signal value；

3) starting standard and product to be tested, measure and flow through product to be tested and electric current Ix (n) of standard substance, Ic (n), wherein n is product to be tested electric current and standard substance current sample is counted；

4) during the data of Synchronization Control collection are stored respectively in following array:

I1 [n]=Ia (t)；I2 [n]=Ib (t)；I3 [n]=Ic (t)；I4 [n]=Id (t)；I5 [n]=Ie (t) Ix [n]=Ix (t)；Ic [n]=Ic (t), the n in above formula are the 1s inter-sync harvester sampling number when the sampling rate of 163840zh, its n=0-163840；

5) above-mentioned array is substituted in following windowing FFT formula:

$i_{n1}=I_0+\underset{n=1}{\overset{k}{\mathrm{\Σ}}}W\left(n\right)*I\left(n\right)*sin(nwt+{\mathrm{\β}}_n);$

Substitution method is by I1 [n], I2 [n], I3 [n], I4 [n], I5 [n], Ix [n], Ic [n], the I (n) that replaces in formula above；

Wherein, i_n1For the frequency domain amplitude that input signal is corresponding, W (n) is windowed function, and I (n) is the amplitude that individual harmonic current is corresponding, I₀For DC component, wt is sampling signal frequency, β_nFor first-harmonic and each harmonic phase angle, n=0～163840, k=1～163840 in above formula；

6) I1 [n], I2 [n], I3 [n], I4 [n] are overlapped process and draw equation below:

Iz (n)=I1 [n]+I2 [n]+I3 [n]+I4 [n]；

I5 [n], Ix [n] are overlapped process and draw equation below: Ix2 (n)=I5 [n]+Ix [n]；

I5 [n], Ic [n] are overlapped process and draw equation below: Ic2 (n)=I5 [n]+Ic [n]；

7) i is substituted with Iz (n)_n1I (n) in expression formula carries out windowing FFT conversion, the phase beta after being converted by windowing FFT_z1, DC component, harmonic components be sent to backstage and store；Ix2 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, the phase beta after being converted by windowing FFT_x2, DC component, harmonic components be sent to backstage and store；Ic2 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after windowing FFT conversion conversion_c2, DC component, harmonic components be sent to backstage and store.

8) noise measurement probe, recording noise measurement probe data simultaneously are closed；

9) output high tension voltage value: 0V-50kv, output high voltage frequency value: 40Hz-75Hz, the tested mode of connection are set；

10) High voltage output is started, after closed loop regulation High voltage output is stable, synchronous averaging noise jamming measuring probe, standard, product to be tested, recording noise interference probe data, its measurement data is stored in following variable: Iec1 [n]=Ia1 (t)；Iec2 [n]=Ib2 (t)；Iec3 [n]=Ic3 (t)；Iec4 [n]=Id4 (t)；Iec5 [n]=Ie5 (t)；Iex [n]=Iex (t)；Iec [n]=Iec (t), the t=1s in above variable, n=163840；

11) Iec1 [n], Iec2 [n], Iec3 [n], Iec4 [n] are overlapped process and draw equation below:

Iecz [n]=Iec 1 [n]+Iec 2 [n]+Iec 3 [n]+Iec 4 [n]；

Iex [n] is deducted Iec5 [n] and draws equation below: Iex2 (n)=Iex [n]-Iec5 [n]-Iz (n)；

Iect1 [n] is deducted Iec5 [n] and draws equation below: Iect1 (n)=Iec [n]-Iec5 [n]；

Iex [n] is deducted Iz (n) and draws equation below: Iex3 (n)=Iex [n]-Iz (n)-Ix2 (n)；

Iec [n] is deducted Iz (n) and draws equation below: Iect2 (n)=Iec [n]-Iz (n)-Ic2 (n)；

Iex [n] standard measurement data in expression formula, Iec [n] product to be tested measurement data；

12) Iecz [n] is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by i_n1Phase beta after converting after windowing FFT conversion_en1, DC component, harmonic components be sent to backstage and store；Iex2 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, the phase beta after being converted by in1 windowing FFT_ex1, DC component, harmonic components be sent to backstage and store；Iect1 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_en2, DC component, harmonic components be sent to backstage and store；Iex3 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_ex2, DC component, harmonic components be sent to backstage and store；Iect2 is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_en3, DC component, harmonic components be sent to backstage and store；

13) assuming noise interferences ratio variable K [n], noise jamming number of variables Imc1 [n] before and after High voltage output, Imc1 [n] transformation for mula is as follows:

K [n]=[Iec5 [n]-Iecz [n]]/[Iec5 [n]-I5 [n]]；Imc1 [n]=Iec5 [n] * [K [n]+1]；

14) Iec [n] is deducted Imc1 [n] and draw equation below: Iect3 (n)=Iec [n]-Imc1 [n]；Iex [n] is deducted Imc1 [n] and draws equation below: Iex4 (n)=Iex [n]-Imc1 [n]；

15) Iect3 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_en3, DC component, harmonic components be sent to backstage and store；Iex4 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_ex4, DC component, harmonic components be sent to backstage and store；

16) step 9 is repeated)～step 15) n times mainly raising test result precision, repeatability, stability, set N and meet condition: 0 < N < 1024, cyclic process condition meets: keep current setting output high pressure constant, output frequency changes stepping and meets: Fre=1024/M, the result that circulation is measured every time is sent to backstage and stores, 0 < M < N；Set β_ex、β_ecIt is Kext, Kect with humiture change correction value；Kext, Kect use linearity correction to draw: Kext=β_exs/β_exm；β_exsFor target setting phase angle, β_exmFor the actual measured phase angle of standard；Kect=β_exs/β_ecm, β_ecmFor the actual measured phase angle of product to be tested；M=0～N-1；

17) to Kext, Kect* β_ec1[m]、Kect*β_ec2[m]、Kect*β_ec3[m] carries out unbiased variance statistics analysis and show that product to be tested statistical analysis draws dielectric loss angle beta_ex；Kect、Kext*β_ex1[m]、Kext*β_ex2[m] carries out unbiased variance statistics analysis and show that product to be tested statistical analysis draws dielectric loss angle beta_en；

18) to β_ex[m]、β_ec[m] carries out multistage curve matching, and fitting formula is as follows:

θ_ex=a* β_ex[m]³+b*β_ex[m]²+c*β_ex[m]+d；

Wherein, β_ex[m] is for repeating step 9)～step 15) the phase angle array that draws of m measurement standard device, θ_exFor product to be tested curve matching dielectric loss angle, a, b, c, d are the revised coefficient of curve matching, m=0～N-1；

θ_en=a1* β_en[m]³+b1*β_en[m]²+c1*β_en[m]+d1；

Wherein, β_ec[m] is for repeating step 9)～step 15) measure the phase angle array that product to be tested draws, θ m time_enFor product to be tested curve matching dielectric loss angle, a1, b1, c1, d1 are the revised coefficient of curve matching, m=0～N-1；

19) by θ_ex、θ_enResult of calculation substitutes into equation below and draws index tan δ: the tan δ=tan (θ for assessing high-voltage electrical equipment insulating properties quality_ex-θ_en)。

K=0～163840；N=0～163840.

Compared with prior art, the had the beneficial effect that present invention of the present invention can solve the deficiency of two kinds of measuring methods of prior art, thus realizes a kind of Portable insulation state estimation measurement apparatus.This kind of method is for accurately detecting the insulation ag(e)ing state characteristic parameter of power equipment, comprehensive assessment Electric Power Equipment Insulation ageing state, thus the stable and reliable operation to electric power network has great realistic meaning.

Accompanying drawing explanation

Fig. 1 is that the present invention portable Condition assessment of insulation system approach realizes device；

Fig. 2 is DC boosting power factor (PF) adjustment module theory diagram of the present invention；

Fig. 3 is buck power factor adjustment module theory diagram of the present invention；

Fig. 4 is that Portable insulation of the present invention assesses system approach flow chart.

Detailed description of the invention

The present invention proposes portable Condition assessment of insulation system approach and realizes device block diagram as shown in Figure 1.nullIncluding: 220v AC power frequency signal suppression module，Exchange turns DC boosting power factor (PF) adjustment module (direct current: 500v～580v)，Buck power factor adjustment module (0v～580v)，Direct current delivers rheology frequency modulation die block (0v～300v)，0v～300v AC harmonic suppression module、H.V. step up transformer (0v～30000v)、Standard and product to be tested module、Kilomega optic fiber data acquisition module (self-adaptive current measurement module、Fiber optic communication、High-speed, high precision synchronous data collection module)，FPGA kilomega optic fiber communication data acquisition control module (fiber optic telecommunications module、High-speed, high precision synchronous data collection module)、Display TT&C software system in backstage (controls parameter and arranges interface、Measure parameter display interface、Report generation interface、Measurement data query interface).

220v AC power frequency supply suppression module is mainly inductively measured transducer, 220v ac current measurement sensor, 220v ac voltage measurement sensor, main circuit power fling-cut switch, full-bridge rectification module etc. formed by Surge Suppressors, alternating current power supply common-mode rejection filters, noise jamming.

Wherein, Surge Suppressors mainly absorbs outside input and the lightning surge voltage of coupling input, thus protects equipment properly functioning；Alternating current power supply common-mode rejection filters mainly suppresses and filters outside input high frequency common-mode signals, thus ensures that inputting 220v power supply signal is stably beneficial to protection and measures；Noise jamming inductively measures transducer and is mainly used in external noise and interference signal are converted into the signal of telecommunication, and the signal of telecommunication after conversion is input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carries out digital quantization measurement；220v ac current measurement sensor is mainly used for being converted into input 220v input AC current signal can be surveyed the signal of telecommunication and be input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carry out digital quantization measurement, and the electric current measured is mainly used in overcurrent protection, HARMONIC SIGNAL EXTRACTION FROM, power frequency component phase calculation；220v ac voltage measurement sensor is mainly used for being converted into input 220v input ac voltage signal can be surveyed the signal of telecommunication and be input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carry out digital quantization measurement, and the voltage measured is mainly used in overvoltage protection, HARMONIC SIGNAL EXTRACTION FROM, power frequency component phase calculation；Main circuit power fling-cut switch is mainly used in when stream or overvoltage occurred in input AC carrying out major loop and turns on and off control, thus plays protection major loop device and be not destroyed；Exchange input 220v is mainly converted into galvanic current pressure by full-bridge rectification module, and the DC voltage after conversion is input to DC boosting power factor (PF) adjustment module.

DC boosting power factor (PF) adjustment module is mainly inductively measured transducer etc. form by by DC voltage measurement sensor, noise jamming after dual pathways isolated form MOSFET driving, interactive MOSFET power tube, boost inductance, interactive MOSFET current metering sensor, boosting.

Wherein, dual pathways isolated form MOSFET drives and mainly realizes FPGA controlled stage and MOSFET power stage electrical isolation, thus avoid the coupling of MOSFET level high-voltage signal to be input to controlled stage, so that making controlled stage actual effect, meanwhile, isolated form is driven to MOSFET power stage provides enough driving electric currents to drive MOSFET normally to work；Interactive MOSFET power tube mainly provides enough driving power for output, simultaneously, interactive MOSFET power tube forms a high speed switch type booster circuit with boost inductance combination, by this booster circuit, the DC voltage after rectification is raised adjustable extent 315v～580v；The current signal produced in boosting loop is mainly converted into by interactive MOSFET current metering sensor can be measured signal and be input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carry out digital quantization process；If the high-voltage signal after boosting is converted into and can measure signal and be input to FPGA kilomega optic fiber communication data acquisition control module and carry out digital quantization process by DC voltage measurement sensor main after boosting.The power factor (PF) regulation of boost module output voltage size adjustment and boost module is to be produced interactive pwm signal control realization by the current signal fed back to, voltage signal by many closed loop PID controls, and this control mode improves output voltage regulation stability, real-time, the power factor (PF) of raising boost module.

After buck power factor adjustment module dual pathways isolated form MOSFET driving, interactive MOSFET power tube, buck inductor, interactive MOSFET current metering sensor, boosting, DC voltage measurement sensor, noise jamming inductively measure transducer etc. and form.

Direct current is delivered rheology frequency modulation die block and is mainly driven module, full-bridge MOSFET power model, voltage transformer module, noise jamming to inductively measure transducer etc. and form by four-way isolated form MOSFET.

Wherein, four-way isolated form MOSFET drives module mainly to realize FPGA controlled stage and MOSFET power stage electrical isolation, thus avoid the coupling of MOSFET level high-voltage signal to be input to controlled stage, so that making controlled stage actual effect, meanwhile, isolated form is driven to MOSFET power stage provides enough driving electric currents to drive MOSFET normally to work；Full-bridge MOSFET power model mainly provides enough driving power for output；Voltage transformer module is mainly to be converted into the output voltage after inversion can be measured signal and be input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carry out digital quantization process；Noise jamming inductively measures transducer and is mainly used in external noise and interference signal are converted into the signal of telecommunication, and the signal of telecommunication after conversion is input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carries out digital quantization measurement.Output voltage size adjustment and output signal frequency are produced complementary PWM signals by the current signal fed back to, voltage signal by many closed loop PID controls and control the realization of full bridge power module, and this control mode improves output voltage regulation and frequency regulation stability, real-time, the power factor (PF) of raising voltage reduction module.

AC harmonic suppression module is mainly by inducer, filter capacitor, noise jamming inductively measures transducer composition, this AC harmonic suppression module mainly filters the sinusoidal signal that the filter of spwm signal is exchange 50Hz of AC frequency conversion module output, filter the Resonance Wave Composition contained in AC signal simultaneously, thus ensure that output AC is pure 50Hz sinusoidal signal, noise jamming inductively measures transducer and is mainly used in external noise and interference signal are converted into the signal of telecommunication, the signal of telecommunication after conversion is input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carries out digital quantization measurement.

nullThe exchange 0～300v voltage that harmonic rejection module exports mainly is converted to the High voltage output exchanging 0～35Kv to standard and product to be tested module by H.V. step up transformer，Again in boost process，High voltage output voltage swing and output frequency are digitized measuring by high voltage potential transformer feedback voltage to FPGA kilomega optic fiber communication synchronization data acquisition module，Digital signal after quantization is sent to FPGA kilomega optic fiber communication synchronization data acquisition and control module through the optical fiber of FPGA kilomega optic fiber communication synchronization data acquisition module，FPGA kilomega optic fiber communication synchronization data acquisition and control module by feed back to measure High voltage output voltage swing carry out closed loop control regulation direct current deliver rheology frequency modulation die block，Thus realize High voltage output voltage and frequency size regulates in real time，Such regulation is greatly improved compatibility and the motility that equipment uses.

Standard and product to be tested module mainly produce a normalized current and product to be tested electric current by connection H.V. step up transformer output high pressure, the electric current produced carries out signal extraction by hardware circuit, signal after extraction is amplified through high pressure programmable amplifying circuit, and the signal after amplification is input to FPGA kilomega optic fiber communication data acquisition module and carries out digital quantization process.The integrated noise jamming of this module inductively measures transducer, noise interferences is converted to measure the signal of telecommunication and is input to FPGA kilomega optic fiber communication data acquisition module and carries out digital quantization process by this transducer, digital signal after numbers above quantification treatment through the fiber-optic transfer of module to FPGA kilomega optic fiber communication synchronization data acquisition and control module, in module, the most integrated noise jamming inductively measures transducer simultaneously, this transducer is mainly used in external noise and interference signal are converted into the signal of telecommunication, the signal of telecommunication after conversion is input to FPGA kilomega optic fiber communication synchronization data acquisition and control module and carries out digital quantization measurement.

FPAG kilomega optic fiber communication synchronization data acquisition and control module mainly realizes gathering noise jamming in 220v AC power frequency supply suppression module and inductively measures transducer signal, 220v ac current measurement sensor, 220v ac voltage measurement sensor signal；In collection DC boosting power factor (PF) adjustment module, after interactive MOSFET current metering sensor, boosting, DC voltage measurement sensor, noise jamming inductively measure transducer signal；In collection buck power factor adjustment module, after interactive MOSFET current metering sensor, blood pressure lowering, DC voltage measurement sensor, noise jamming inductively measure transducer signal；Gather direct current and deliver voltage measurement transformer in rheology frequency modulation die block, noise jamming measurement of inductance transducer signal.FPGA kilomega optic fiber communication synchronization data acquisition and control module realizes measuring sensor and the transducer signal that DC boosting power factor (PF) adjustment module feeds back to, realize closed loop PID by the signal fed back to and produce interactive MOSFET power model in interactive pwm signal control DC boosting power factor (PF) adjustment module, thus realize DC boosting power factor (PF) adjustment module output DC voltage and regulate in real time；FPGA kilomega optic fiber communication synchronization data acquisition and control module realizes measuring sensor and the transducer signal that buck power factor adjustment module feeds back to, realize closed loop PID by the signal fed back to and produce interactive MOSFET power model in interactive pwm signal control buck power factor adjustment module, thus realize buck power factor adjustment module output DC voltage and regulate in real time；FPGA kilomega optic fiber communication synchronization data acquisition and control module receives high tension voltage value, the frequency values that FPGA kilomega optic fiber communication synchronization data acquisition module feeds back to, and high tension voltage value, frequency values that FPGA kilomega optic fiber communication synchronization data acquisition and control module and feeds back to voltage transformer according to measurement do closed loop control and realize regulation output HIGH voltage value size and output voltage frequency in real time；FPGA kilomega optic fiber communication synchronization data acquisition and control module receives noise jamming in FPGA kilomega optic fiber communication synchronization data acquisition module standard electric current, product to be tested electric current and the standard measured and product to be tested module and inductively measures transducer voltage, FPGA kilomega optic fiber communication synchronization data acquisition and control module by collect signal, control parameter, signal packing that FPGA kilomega optic fiber communication synchronization data acquisition module feeds back to is sent to backstage built-in touch panel type display by high-speed USB communication interface and carries out relevant parameter and show and curve plotting.FPGA kilomega optic fiber communication synchronization data acquisition and control module also is responsible for receiving embedding simultaneously is the control parameter that touch-screen display feeds back to, and this controls parameter and mainly coordinates closed loop PID control regulation output high direct voltage, DC low-voltage, AC low-tension, booster transformer high pressure and frequency size.

FPGA kilomega optic fiber communication synchronization data acquisition module mainly realizes gathering H.V. step up transformer mesohigh voltage transformer output voltage and noise jamming inductively measures converter output voltage；Collection standard and product to be tested module Plays device electric current, product to be tested electric current；Realize high-pressure side and low-pressure end electrical isolation, it is ensured that control is stablized safe and reliable；Realization automatically controls the amplification of amplifying circuit by the electric current measured and transducer voltage, is arranged by amplification and realizes reliable and stable Collection.The electric current collected, voltage signal packing are sent to FPGA kilomega optic fiber communication synchronization data acquisition and control module by optic module by FPGA kilomega optic fiber communication synchronization data acquisition module.

Backstage display TT&C software system mainly realize show FPAG kilomega optic fiber communication synchronization data acquisition and control module feed back to current signal, voltage signal, interfering noise signal, voltage signal, current signal, interfering noise signal are shown in graph form simultaneously；Display backstage sets DC boosting power factor (PF) adjustment module output current/voltage, buck power factor adjustment module output current/voltage, direct current delivers rheology frequency modulation die block output AC voltage and direct current delivers rheology frequency modulation die block output voltage frequency；Display product to be tested dielectric loss value, capacitance, apparent energy value；Show every one-level noise interferences voltage magnitude；Display standard and product to be tested module Plays device electric current and product to be tested current spectrum analysis chart.

The square law device of the use present invention carries out calibration experiment to the standard dielectric loss device of, and calibration experiment reference standard is JJG563-2004 " high-voltage capacitance electric bridge ", and experimental data is as shown in the table:

By above testing parameter data table, apparatus of the present invention using method and measurement device precision is high, measurement data is accurate.

Claims (2)

1. an Electric Power Equipment Insulation state evaluating method, it is characterised in that comprise the following steps:

1) Initialize installation noise and interference probe, is individually positioned in power frequency letter by noise and interference probe Number suppression module, boost power factor adjustment module, buck power factor adjustment module, friendship On stream harmonic rejection module, standard and product to be tested；

2) start noise and interferometry probe, read t noise and interference probe A, B, C, Signal Ia (t) of D, E, Ib (t), Ic (t), Id (t), Ie (t), Temp (t), Hum (t), Wherein t is noise and interference probe sampling time, Temp (t) and Hum (t) be t temperature, Humidity reads signal value；

3) start standard and product to be tested, measure and flow through product to be tested and electric current Ix (n) of standard substance, Ic (n), Wherein n is product to be tested electric current and standard substance current sample is counted；

4) during the data of Synchronization Control collection are stored respectively in following array:

I1 [n]=Ia (t)；I2 [n]=Ib (t)；I3 [n]=Ic (t)；I4 [n]=Id (t)；I5 [n]= Ie (t) Ix [n]=Ix (t)；Ic [n]=Ic (t), in above formula N be the 1s inter-sync harvester sampling number when the sampling rate of 163840zh, its N=0-163840；

5) above-mentioned array is substituted in following windowing FFT formula:

$i_{n1}=I_0+\underset{n=1}{\overset{k}{\mathrm{\&Sigma;}}}W\left(n\right)*I\left(n\right)*sin(nwt+{\mathrm{\&beta;}}_n);$

Substitution method be by I1 [n], I2 [n], I3 [n], I4 [n], I5 [n], Ix [n], Ic [n], Replace the I (n) in formula above；

Wherein, i_n1For the frequency domain amplitude that input signal is corresponding, W (n) is windowed function, and I (n) is The amplitude that individual harmonic current is corresponding, I₀For DC component, wt is sampling signal frequency, β_n For first-harmonic and each harmonic phase angle, n=0～163840, k=1～163840 in above formula；

6) I1 [n], I2 [n], I3 [n], I4 [n] are overlapped process and draw equation below:

Iz (n)=I1 [n]+I2 [n]+I3 [n]+I4 [n]；

I5 [n], Ix [n] are overlapped process and draw equation below: Ix2 (n)=I5 [n]+Ix [n]；

I5 [n], Ic [n] are overlapped process and draw equation below: Ic2 (n)=I5 [n]+Ic [n]；

7) i is substituted with Iz (n)_n1I (n) in expression formula carries out windowing FFT conversion, is become by windowing FFT Phase beta after changing_z1, DC component, harmonic components be sent to backstage and store；By Ix2 (n) Substitute i_n1I (n) in expression formula carries out windowing FFT conversion, the phase after being converted by windowing FFT Position β_x2, DC component, harmonic components be sent to backstage and store；Ic2 (n) is substituted i_n1 I (n) in expression formula carries out windowing FFT conversion, by the phase place after windowing FFT conversion conversion β_c2, DC component, harmonic components be sent to backstage and store.

8) noise measurement probe, recording noise measurement probe data simultaneously are closed；

9) output high tension voltage value: 0V-50kv, output high voltage frequency value: 40Hz-75Hz, quilt are set The test mode of connection；

10) starting High voltage output, after closed loop regulation High voltage output is stable, synchronous averaging noise jamming is surveyed Amount probe, standard, product to be tested, recording noise interference probe data, its measurement data It is stored in following variable: Iec1 [n]=Ia1 (t)；Iec2 [n]=Ib2 (t)；Iec3 [n]=Ic3 (t)；Iec4 [n]=Id4 (t)；Iec5 [n]=Ie5 (t)；Iex [n]=Iex (t)；Iec[n] =Iec (t), the t=1s in above variable, n=163840；

11) Iec1 [n], Iec2 [n], Iec3 [n], Iec4 [n] are overlapped process and draw following public affairs Formula:

Iecz [n]=Iec 1 [n]+Iec 2 [n]+Iec 3 [n]+Iec 4 [n]；

Iex [n] is deducted Iec5 [n] and draws equation below: Iex2 (n)=Iex [n]-Iec5 [n]-Iz (n)；

Iect1 [n] is deducted Iec5 [n] and draws equation below: Iect1 (n)=Iec [n]-Iec5 [n]；

Iex [n] is deducted Iz (n) and draws equation below: Iex3 (n)=Iex [n]-Iz (n)-Ix2 (n)；

Iec [n] is deducted Iz (n) and draws equation below: Iect2 (n)=Iec [n]-Iz (n)-Ic2 (n)；

Iex [n] standard measurement data in expression formula, Iec [n] product to be tested measurement data；

12) Iecz [n] is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by i_n1Windowing Phase beta after converting after FFT_en1, DC component, harmonic components be sent to backstage and enter Row storage；Iex2 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, by i_n1 Phase beta after windowing FFT conversion_ex1, DC component, harmonic components be sent to backstage and carry out Storage；Iect1 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, will become Phase beta after changing_en2, DC component, harmonic components be sent to backstage and store；By Iex3 (n) Substitute i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_ex2、 DC component, harmonic components are sent to backstage and store；Iect2 is substituted i_n1Expression formula In I (n) carry out windowing FFT conversion, will conversion after phase beta_en3, DC component, humorous Wave component is sent to backstage and stores；

13) noise interferences ratio variable K [n], noise jamming series before and after High voltage output is assumed Variable Imc1 [n], Imc1 [n] transformation for mula is as follows:

K [n]=[Iec5 [n]-Iecz [n]]/[Iec5 [n]-I5 [n]]；Imc1 [n]=Iec5 [n] * [K [n]+1]；

14) Iec [n] is deducted Imc1 [n] and draw equation below: Iect3 (n)=Iec [n]-Imc1 [n]；Will Iex [n] deducts Imc1 [n] and draws equation below: Iex4 (n)=Iex [n]-Imc1 [n]；

15) Iect3 (n) is substituted i_n1I (n) in expression formula carries out windowing FFT conversion, will conversion After phase beta_en3, DC component, harmonic components be sent to backstage and store；By Iex4 (n) Substitute i_n1I (n) in expression formula carries out windowing FFT conversion, by the phase beta after conversion_ex4、 DC component, harmonic components are sent to backstage and store；

16) repeat step 9)～step 15) n times mainly improve test result precision, repeatability, Stability, sets N and meets condition: 0 < N < 1024, and cyclic process condition meets: keep Current setting output high pressure is constant, and output frequency changes stepping and meets: Fre=1024/M, often The result that secondary circulation is measured is sent to backstage and stores, 0 < M < N；Set β_ex、β_ecWith Humiture change correction value is Kext, Kect；Kext, Kect use linearity correction to draw: Kext=β_exs/β_exm；β_exsFor target setting phase angle, β_exmMeasure for standard is actual Phase angle；Kect=β_exs/β_ecm, β_ecmFor the actual measured phase angle of product to be tested；M=0～N-1；

17) to Kext, Kect* β_ec1[m]、Kect*β_ec2[m]、Kect*β_ec3[m] carries out mean square Difference statistical analysis show that product to be tested statistical analysis draws dielectric loss angle beta_ex；Kect、Kext* β_ex1[m]、Kext*β_ex2[m] carries out unbiased variance statistics analysis and draws product to be tested statistical analysis Draw dielectric loss angle beta_en；

18) to β_ex[m]、β_ec[m] carries out multistage curve matching, and fitting formula is as follows:

θ_ex=a* β_ex[m]³+b*β_ex[m]²+c*β_ex[m]+d；

Wherein, β_ex[m] is for repeating step 9)～step 15) phase that draws of m measurement standard device Parallactic angle array, θ_exFor product to be tested curve matching dielectric loss angle, a, b, c, d are curve The revised coefficient of matching, m=0～N-1；

θ_en=a1* β_en[m]³+b1*β_en[m]²+c1*β_en[m]+d1；

Wherein, β_ec[m] is for repeating step 9)～step 15) measure what product to be tested drew for m time Phase angle array, θ_enFor product to be tested curve matching dielectric loss angle, a1, b1, c1, d1 For the revised coefficient of curve matching, m=0～N-1；

19) by θ_ex、θ_enResult of calculation substitutes into equation below and draws for assessing high-voltage electrical equipment exhausted Index tan δ: the tan δ=tan (θ of edge performance quality_ex-θ_en)。

Electric Power Equipment Insulation state evaluating method the most according to claim 1, it is characterised in that K=0～163840；N=0～163840.