CN105510742B - A kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method - Google Patents
A kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method Download PDFInfo
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
A kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method, it is characterized in that：Exciting test is carried out to test item using low-frequency power；Measured using high-speed measuring device and test winding voltage current waveform u when testing1(t), i (t), and open circuit side voltage waveform u2(t), row write circuit port voltage equation (wherein u2(t) reduction is to testing side), due to open circuit, open a way side voltage u2(t) induced potential e (t) of winding etc. is approximately equal to, its advantage is：Experiment can be completed under conditions of far below power-frequency voltage, the capacity required for experiment is greatly reduced, is effectively reduced during testing for personnel and the security risk of test item；Transformer test side winding leakage reactance can be calculated using voltage x current data during experiment, establishes the exact circuitry equivalent model containing leakage inductance, the influence of leakage reactance is considered in derivation；The quality and volume of testing equipment are reduced, test efficiency can be effectively improved with short form test wiring.
Description
Technical field
C-V characteristic (or excitation property) is carried out the present invention relates to electric power with transformer, transformer, reactor to test, especially
Suitable for carrying out volt-ampere characteristic test to the larger transformer that can not ignore of leakage reactance.
Technical background
The ferromagnetic coil part such as transformer, reactor and transformer is as critical elements in power system, with power transmission and transformation
The voltage class and capacity of the increase transformer of capacity gradually increase, with the shunt reactor of the growth compensation of transmission distance
Capacity it is also increasing, the voltage class more and more higher of current transformer and voltage transformer, under being nonserviceabled to it
Transient characterisitics propose new requirement.Therefore there is the performance quality of unshakable in one's determination and loop construction ferromagnetic element to be related to electric power for these
The safe and stable operation of system, and the performance test to these ferromagnetic elements is to check the important technical of its performance, is passed through
It can be found that transformer has a defective insulation between silicon steel sheet to transformer noload losses and the test of no-load current, interpolar unshakable in one's determination,
The insulated part damage of partial short-circuit scaling loss between piece, punching bolt or colligation steel band, pressing plate, upper yoke etc., form short circuit, magnetic circuit
Middle silicon steel sheet loosens, misplaced, air gap is too big, and multipoint earthing unshakable in one's determination, coil has turn-to-turn, layer short circuit or the parallel branch number of turn not
Deng, ampere-turn imbalance etc., the defects of having misapplied high consumption silicon steel sheet inferior or design there are errors in computation, by transformer iron core performance
The quality of the design of effecting reaction transformer, manufacturing process defect, material and performance is capable of in experiment, such as：Secondary winding turn-to-turn or
Situations such as layer short circuit, iron core or coil loosen, displacement.
With the increase of ferromagnetic element capacity so that equipment is heavy during field test, lifting is difficult, and potential safety hazard is more and work
It is low to make efficiency.New transient protection is up to tens thousand of volt even more highs with transformer up to flex point potential, considerably beyond transformer
Turn-to-turn and tolerance insulation over the ground, thus conventional power frequency excitation property test method cannot be guaranteed test item and secondary connection
The safety of terminal, and it is larger to test place capacity needed for process, it is higher to apply voltage, the person and equipment safety hidden danger be present.
At present, existing researcher proposes the test method using low-frequency variable-frequency power source measurement voltage-current characteristic of ferromagnetic element
With compensation calculation method, the basic theories of this method still is based on IEC60044-6 low-frequency power test method(s), additionally to iron
The magnetic hystersis loss of core and the influence of eddy-current loss are analyzed and calculated so that the result of the test under low frequency is closer to work
Frequency result of the test.But there is the problem of two aspects in this method：1) sine that frequency range is larger, output capacity is big
The research and development difficulty of ripple power supply is big, and cost is high；2) some simplification have been carried out to the model of transformer, has not accounted for transformer leakage inductance
Influence, cause result of the test that there is difference.
The content of the invention
Under such background condition, small-power and low-voltage variable-frequency power sources are used the purpose of the present invention is to propose to a kind of
The test method and analysis calculation method of the C-V characteristic of measuring transformer, this method are also applied for transformer, reactance utensil
The cored and power equipment of loop construction.The result of this test method has one with power frequency (50Hz or 60Hz) measured result
Cause property.
Technical solution of the present invention is：
A kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method, its feature
It is：
1) test connection is carried out as shown in Figure 1, and exciting test is carried out to test item using low-frequency power.Measured using high speed
Winding voltage current waveform u is tested when measurement device is tested1(t), i (t), and open circuit side voltage waveform u2(t), row write circuit
Port voltage equation (wherein u2(t) reduction is to testing side), due to open circuit, open a way side voltage u2(t) it is approximately equal to the sense of winding
Answer potential e (t)；
2) equivalent-circuit model of Circuit Fault on Secondary Transformer is established, considers that the leakage inductance of transformer directly hinders, magnetic hystersis loss and vortex
Loss；The circuit by magnetizing inductance Lm, be eddy-current loss equivalent resistance Re, hysteresis loss resistance RhParallel connection is again with testing side leakage sense L
σ and D.C. resistance RdcIt is composed in series；The straight resistance R of ferromagnetic element before experimentdc, leakage inductance LσValue can be calculated by ferromagnetic element nameplate
Go out, u1(t) it is experiment side voltage, e (t) is transformer experiment side induced electromotive force, im(t) it is to flow through main excitation LmBranch road
Electric current, ie(t) equivalent current, i are vortexedh(t) it is magnetic hystersis loss equivalent current, i (t) is the total exciting current of experiment, and P is that experiment has
Work(power, PTIt is winding iron core loss；
3) different frequency f is applied to subject ferromagnetic element1、f2Voltage, make core sataration, measure active-power P1With
P2, total exciting current i1And i (t)2(t) experiment side active power, can be calculated by the voltage x current temporal pattern of collection：
The now induced electromotive force of winding：
4) the core loss P under different frequency is calculated by formula (3)T1、PT2, wherein I1、I2For exciting current under different frequency
Virtual value；
5) core loss and frequency meet relational expression (4), to same transformer, in the case where same magnetic is close, We、WhIt is constant,
WhFor each cycle magnetic hystersis loss (W/Hz)；WeF is each cycle eddy-current loss (W/Hz).Can according to core loss is tested twice
Try to achieve We、WhValue；
6) transformer is demagnetized so that iron core residual flux ψ0=0；Transformer secondary winding is applied by low-frequency power
Add the constant voltages of frequency f, according to the situation of subject transformer, the frequency f of power supply output should be suitable, and power supply capacity is enough to make change
Depressor core sataration；Slowly rise voltage, until iron core reaches depth saturation, in the process, using the instrument of high-speed sampling,
Measure and record the instantaneous voltage u (t) and exciting current instantaneous value i (t) of application；
7) test data under power supply low frequency f is changed to power frequency f0Under data；According to induced potential and vortex, magnetic hysteresis
Equivalent resistance can calculate eddy loss currents ie(t), calculation formula is as follows：
8) eddy loss currents under low frequency are converted to power frequency by frequency relation, IenFor conversion to industrial frequency experiment amount：
Ien=Ie·fn/f (7)
Overall test electric current after compensation under power frequency is Iexn：
Iexn=Iex-Ie+Ien(8)；
9) due to needing to compensate the voltage drop in straight resistance and leakage inductance according to exciting current instantaneous value after compensation, can directly press
Ratio converts exciting current instantaneous value：
iexn(t)=kiex(t) (9)
In formula, k is proportionality coefficient k=Iexn/Iex, and last can calculates the excitation voltage under power frequency, induction electric
Gesture can directly be converted by frequency, and straight resistance and the pressure drop of leakage inductance need to be calculated with the electric current after compensation：
10) current and voltage data being scaled under power frequency is calculated into its virtual value, using voltage as ordinate, electric current is horizontal seat
Mark, it is possible to make the VA characteristic curve under industrial frequency experiment, complete the test of C-V characteristic.
Beneficial effects of the present invention are：
1. experiment can be completed under conditions of far below power-frequency voltage, the capacity required for experiment is greatly reduced, effectively
Reduce during testing for personnel and the security risk of test item；
2. transformer test side winding leakage reactance can be calculated using voltage x current data during experiment, establish containing leakage
The exact circuitry equivalent model of sense, the influence of leakage reactance is considered in derivation；
3. reducing the quality and volume of testing equipment, test efficiency can be effectively improved with short form test wiring.
Brief description of the drawings
Fig. 1 volt-ampere characteristic test equivalent circuits；
Fig. 2 parameter recognition principle figures；
Fig. 3 VA characteristic curves.
Embodiment
The invention will be further described below in conjunction with the accompanying drawings.
A kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method, the present invention are special
Sign is：
1) test connection is carried out as shown in Figure 1, and exciting test is carried out to test item using low-frequency power；Measured using high speed
Winding voltage current waveform u is tested when measurement device is tested1(t), i (t), and open circuit side voltage waveform u2(t), row write circuit
Port voltage equation (wherein u2(t) reduction is to testing side), due to open circuit, open a way side voltage u2(t) it is approximately equal to the sense of winding
Answer potential e (t)；
2) equivalent-circuit model of Circuit Fault on Secondary Transformer is established, as shown in Fig. 2 wherein RdcDirectly hindered for winding, L σ are experiment
Side leakage sense (the straight resistance R of ferromagnetic element before experimentdc, leakage inductance LσValue can be calculated by ferromagnetic element nameplate), Lm is excitatory electricity
Sense, ReFor eddy-current loss equivalent resistance, RhFor hysteresis loss resistance.u1(t) it is experiment side voltage, e (t) is transformer induction
Electromotive force, im(t) it is to flow through main excitation LmThe electric current of branch road, ie(t) equivalent current, i are vortexedh(t) it is magnetic hystersis loss equivalent electric
Stream, i (t) are the total exciting currents of experiment, and P is to test active power, PTIt is winding iron core loss；
3) different frequency f is applied to subject ferromagnetic element1、f2Voltage, make core sataration, measure active-power P1With
P2, total exciting current i1And i (t)2(t) experiment side active power, can be calculated by the voltage x current temporal pattern of collection：
The now induced electromotive force of winding：
4) the core loss P under different frequency is calculated by formula (3)T1、PT2, wherein I1、I2For exciting current under different frequency
Virtual value；
5) core loss and frequency meet relational expression (4), to same transformer, in the case where same magnetic is close, We、WhIt is constant,
WhFor each cycle magnetic hystersis loss (W/Hz)；WeF is each cycle eddy-current loss (W/Hz).Can according to core loss is tested twice
Try to achieve We、WhValue；
6) transformer is demagnetized so that iron core residual flux ψ0=0；Transformer secondary winding is applied by low-frequency power
Add the constant voltages of frequency f, according to the situation of subject transformer, the frequency f of power supply output should be suitable, and power supply capacity is enough to make change
Depressor core sataration；Slowly rise voltage, until iron core reaches depth saturation, in the process, using the instrument of high-speed sampling,
Measure and record the instantaneous voltage u (t) and exciting current instantaneous value i (t) of application；
7) test data under power supply low frequency f is changed to power frequency f0Under data；According to induced potential and vortex, magnetic hysteresis
Equivalent resistance can calculate eddy loss currents ie(t), calculation formula is as follows：
8) eddy loss currents under low frequency are converted to power frequency by frequency relation, IenFor conversion to industrial frequency experiment amount：
Ien=Ie·fn/f (7)
Overall test electric current after compensation under power frequency is Iexn：
Iexn=Iex-Ie+Ien(8)；
9) due to needing to compensate the voltage drop in straight resistance and leakage inductance according to exciting current instantaneous value after compensation, can directly press
Ratio converts exciting current instantaneous value：
iexn(t)=kiex(t) (9)
In formula, k is proportionality coefficient k=Iexn/Iex, and last can calculates the excitation voltage under power frequency, induction electric
Gesture can directly be converted by frequency, and straight resistance and the pressure drop of leakage inductance need to be calculated with the electric current after compensation：
10) current and voltage data being scaled under power frequency is calculated into its virtual value U0、I0, using voltage as ordinate, electric current is
Abscissa, it is possible to make the VA characteristic curve under industrial frequency experiment, complete the test of C-V characteristic.
Claims (1)
1. a kind of test method tested using low-frequency power transformer C-V characteristic and analysis calculation method, it is characterized in that：
1) exciting test is carried out to test item using low-frequency power；Winding voltage is tested when measuring and test using high-speed measuring device
Current waveform u1(t), i (t), and open circuit side reduction to test side voltage waveform u2(t), row write circuit port voltage equation,
Due to open circuit, open a way side voltage u2(t) it is approximately equal to the induced potential e (t) of winding；
2) equivalent-circuit model of Circuit Fault on Secondary Transformer is established, considers that the leakage inductance of transformer directly hinders, magnetic hystersis loss and eddy-current loss；
The circuit is by magnetizing inductance Lm, eddy-current loss equivalent resistance Re, hysteresis loss resistance RhParallel connection is again with testing side leakage sense Lσ With it is straight
Leakage resistance RdcIt is composed in series；The D.C. resistance R of transformer before experimentdc, leakage inductance LσValue can be calculated by ferromagnetic element nameplate,
u1(t) it is experiment side voltage, e (t) is transformer experiment side induced electromotive force, im(t) it is to flow through main excitation LmThe electricity of branch road
Stream, ie(t) it is vortex equivalent current, ih(t) it is magnetic hystersis loss equivalent current, iex(t) it is the total exciting current of experiment, P is experiment
Active power, PTIt is winding iron core loss；
3) different frequency f is applied to subject transformer1、f2Voltage, make core sataration, measure active-power P1And P2, always encourage
Magnetoelectricity stream i1And i (t)2(t) experiment side active power, can be calculated by the voltage x current temporal pattern of collection：
The now induced electromotive force of winding：
4) the core loss P under different frequency is calculated by formula (3)T1、PT2, wherein I1、I2It is effective for exciting current under different frequency
Value；
5) core loss and frequency meet relational expression (4), to same transformer, in the case where same magnetic is close, We、WhIt is constant, WhFor
Each cycle magnetic hystersis loss (W/Hz)；WeF is each cycle eddy-current loss (W/Hz)；It can be tried to achieve according to experiment core loss twice
We、WhValue；
6) transformer is demagnetized so that iron core residual flux ψ0=0；Frequency is applied to transformer secondary winding by low-frequency power
Voltage constant rate f, according to the situation of subject transformer, the frequency f of power supply output should be suitable, and power supply capacity is enough to make transformer
Core sataration；Slowly rise voltage, until iron core reaches depth saturation, in the process, use the instrument of high-speed sampling, measurement
And record the instantaneous voltage u (t) and exciting current instantaneous value i of applicationex(t)；
7) test data under power supply low frequency f is changed to power frequency f0Under data；Can be with according to induced electromotive force and eddy-current loss
Calculate eddy loss currents ie(t), calculation formula is as follows：
8) eddy loss currents under low frequency are converted to power frequency by frequency relation, IenFor conversion to industrial frequency experiment amount：
Ien=Ie·fn/ f, wherein fnAs power frequency (7)
Overall test electric current after compensation under power frequency is IexnWherein Iex" it is exciting current iex(t) virtual value
Iexn=Iex-Ie+Ien(8)；
9), can directly in proportion due to needing to compensate the voltage drop in straight resistance and leakage inductance according to exciting current instantaneous value after compensation
Convert exciting current instantaneous value：
iexn(t)=kiex(t) (9)；
In formula, k is proportionality coefficient k=Iexn/Iex, and last can calculates the excitation voltage under power frequency, and induced electromotive force can
Directly converted by frequency, straight resistance and the pressure drop of leakage inductance need to be calculated with the electric current after compensation：
10) current and voltage data being scaled under power frequency is calculated into its virtual value, using voltage as ordinate, electric current is abscissa,
Can makes the VA characteristic curve under industrial frequency experiment, completes the test of C-V characteristic.
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| CN107607790A (en) * | 2017-09-21 | 2018-01-19 | 云南电网有限责任公司电力科学研究院 | The translation method of the lower converters core loss of difference excitation |
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