CN106610473A - Electrical parameter testing method based on static frequency response test of synchronous generator - Google Patents

Abstract

The invention relates to an electrical parameter testing method based on a static frequency response test of a synchronous generator. Test data of asynchronous operation states of the synchronous data under different slip frequencies is obtained, filtering and spectral analysis are carried out on recording data of stator voltage, stator current and excitation current in different frequencies, and Park transformation is carried out on the stator voltage and current to obtain voltages and currents in quadrature and direct axes respectively; and the stator voltage, the stator current, the excitation current, a resistance of a stator winding and synchronous reactance of the quadrature and direct axes in the corresponding frequency are known, an operational reactance and excitation winding transfer function in different frequencies is solved, a frequency related characteristic curve is obtained, a characteristic curve of the operational reactance of the direct axis is fit with a characteristic curve of the operational reactance of the quadrature axis, and a synchronizer parameter is output.

Description

Electrical parameters measure method based on synchronous generator rest frequency response test

Technical field

The present invention is, based on the parameter test method under synchronous generator rotor inactive state, to belong to Synchronous generator electric parameter measurement technology field.

Background technology

The capacity and scale of China's electrical network increasingly increases, and security issues become increasingly urgent for power system, , used as the important step of simulation calculation, the accuracy of its parameter will be straight for the model and parameter of generator Connect and have influence on Model for Stability Calculation of Power System result.

At different frequencies external characteristics is different for synchronous generator, for one or more frequencies, Many set parameters may be needed.In the last few years, the points for large-scale pit-head power station occur in power system more The method of operation is mended to guipure string, needs to carry out subsynchronous resonance analysis and suppression technology to generator Research, need one or more groups of parameters accurately to emulate the generating under different shafting frequencies Machine external characteristics.

Generator parameter test relatively common at present is broadly divided into waving map method and frequency domain Method of testing and the method that FEM calculation is carried out according to design parameter.

Waving map method mainly has the type approval test that (1) is routinely carried out in motor manufacturing producer (no-load characteristic, short circuit curve, Sudden Three-phase Short Circuit test and static two-phase rotation mensuration), This method can accurately determine d-axis parameter, but can not provide accurate quadrature axis parameter. (2) load method is thrown, similar to sudden short circuit test above, by electricity during measurement disturbance suddenly The time response of machine variable carrys out the characteristic of identifying motor.This test is there is provided d-axis and quadrature axis Data, but it is motor under synchronous operation operating mode that this test can obtain more horn of plenty, And the information after super transition, and be difficult in test data comprising the relatively slow information of change, Such as the information under asynchronous operation operating mode.

Frequency domain test method mainly has (1) IEEE GUIDE:TEST PROCEDURES It is specific that FOR SYNCHRONOUS MACHINES (IEEE Std 115-1995) recommend The rest frequency response of position, unit is in stopped status (stationary rotor), and and Solutions of Systems Row, it is necessary to harmonize in two ad-hoc locations relative to stator, with one from 0.001～1000Hz The low level power supply of whole frequency range carrys out energized stator, for synchronous generator is come rotor of harmonizing Two ad-hoc locations, i.e. d-axis position and quadrature axis position be difficult, position it is inaccurate right The error of parameter testing affects very big；(2) open loop frequency response method, unit is opened at lower voltages Road is run, and magnetic field measures excitation to the frequency response of stator with various frequency excitations, can only Confirm some data of d-axis in intermediate frequency range；(3) online frequency response method, machine passes through one Individual big impedance is connected to system, and with close rated load operation, excitation is adjusted with sinusoidal random noise System.Derive with the component decomposed on two axles and similar to the data of rest frequency response method One model.But the frequency range of this method data available is less than rest frequency response method.

When the parameter that the above method of testing is obtained is used to study Sub-synchronous Resonance, not The result matched with real system can be obtained, be may result in and put into practice complete phase with Practical Project Anti- conclusion.

The content of the invention

The technical problem to be solved is that offer one kind being capable of accurate description synchronization The electrical parameters measure method of motor different frequency external characteristics, the method is turned using synchronous generator Sub- inactive state test obtains the measurement data of test synchronous generator electric parameter.

The present invention adopts following scheme：It is a kind of based on synchronous generator rest frequency response test Electrical parameters measure method, comprises the steps of：

A, the test data for obtaining synchronous motor asynchronous operation state under different slip frequencies, institute Test data is stated including at least generator unit stator voltage, electric current and Exciting Windings for Transverse Differential Protection electric current；

B, stator voltage and electric current to different frequency, the recorder data of exciting current are filtered Ripple, spectrum analysis, to stator voltage and electric current Park Transformation is carried out, and respectively obtains ac-dc axis electricity Pressure and electric current；

C, the stator voltage of different frequency and stator current, exciting current, the electricity of stator winding Resistance, the synchronous reactance of ac-dc axis be all, it is known that and meet the relation of formula 1, set up different frequency D-axis operational Impedance X_d(j) and quadrature axis operational Impedance X_q(j), Exciting Windings for Transverse Differential Protection transmission function G_fThe equation group of (j), and solve

Formula 1

Wherein r_aStator DC resistance, j be plural number imaginary unit, X_d(j) and X_qJ () is the frequency The operational Impedance of generator d-axis and quadrature axis, G under rate_fJ () is that the Exciting Windings for Transverse Differential Protection under the frequency is passed Delivery function；

d、X_d(j) and X_q(j)、G_fThe following relation of satisfaction between (j) and the parameter of electric machine

Formula 2

x_dFor direct-axis synchronous reactance, x '_dFor direct-axis transient reactance, x_d" for the super transient state electricity of d-axis Anti-, T_d' it is d-axis transient time constant, T_d" for the super transient time constant of d-axis, T '_doOpen for stator D-axis transient time constant during road, T_do" the super transient time constant of d-axis when opening a way for stator, x_qFor quadrature axis synchronous reactance, x '_qFor quadrature axis transient reactance, x_q" it is quadrature axis ultra-transient reactance, T_q' For direct transient time constant, T_q" for the super transient time constant of quadrature axis, x_adIt is anti-for d-axis armature Answer reactance, T_DσFor leakage field time constant, the r of d-axis Damper Winding_fFor Exciting Windings for Transverse Differential Protection resistance； Wherein x_d、T’_do、x_q、r_a、x_adFor energy in the measurement test of conventional synchronous generator parameter accurately The parameter of acquisition, it is believed that be known parameters；

General, x_d、T'_do、x_q、r_a、x_adFor energy in conventional synchronous generator type approval test The parameter for accurately obtaining, using the d-axis operational Impedances and quadrature axis operational Impedance of 4 pairs of acquisitions of formula, Exciting Windings for Transverse Differential Protection transmission function frequency characteristic, carries out curve fitting, it is possible to obtain test frequency Under electric parameter, including x '_d、x_d″、T_d'、T_d″、x′_q、x_q″、T_q'、T_q″、r_f、 T_Dσ。

Wherein stationary rotor is motionless at an arbitrary position, and stator side accesses variable-frequency power sources by breaker, Generator excitation winding short circuit；The two-phase being incorporated into respectively in breaker three-phase, then it is incorporated into breaker Three-phase, final each frequency can obtain three groups of asymmetric stationary rotor status datas, and one The stationary rotor status data of group three-phase symmetrical.

Variable-frequency power sources needed for present invention test is in Whole frequency band (0.01Hz～100Hz) range content Amount is all sufficiently large, and the present invention can be depicted the frequency response characteristic of synchronous motor in Whole frequency band, The electric parameter of synchronous motor is nonlinear change with frequency, therefore different Frequency points, together The parameter of step motor is to differ, and selects CF point to synchronize according to actual requirement of engineering The parameter testing of motor, just can meet to motor different frequency point accurate description.

Description of the drawings

Fig. 1 is the test connection of the present invention.

Fig. 2 is that the synchronous motor rest frequency response parameter of the present invention surveys the step of distinguishing method stream Cheng Tu.

Specific embodiment

As shown in figure 1, the mode of connection of the present invention using unit-experiment power supply, excitation system Exit, Exciting Windings for Transverse Differential Protection loop is by cable short circuit；The rotor of synchronous motor is quiet at an arbitrary position It is only motionless, dextral variable frequency supply frequency is set as into a certain assigned frequency, breaker is incorporated into respectively Two-phase in three-phase, then breaker three-phase is incorporated into, in breaker actuation, start transient state record ripple Harvester, start recording set end voltage, electric current and Exciting Windings for Transverse Differential Protection electric current.In the timing of collection one Between section data after, cut-off breaker.Final each frequency can obtain three groups it is asymmetric Stationary rotor status data, the stationary rotor status data of one group of three-phase symmetrical.

Under stationary rotor state, when synchronous motor stator (three-phase or two-phase) accesses variable-frequency electric During source, stator voltage and stator current obtain ac-dc axis voltage, electric current through Park Transformation, such as Formula 3 and formula 4, wherein θ is the angle between d-axis and A phase voltage phasors.

Formula 3

Formula 4

Wherein：U_A, U_B, U_C, it is threephase stator voltage_,I_A, I_B, I_C, it is threephase stator electricity Stream U_d, U_q, U₀For three-phase ac-dc axis voltage, I_d, I_q, I_0,Three-phase ac-dc axis electric current.

There is the relation of formula 1, X between ac-dc axis voltage, electric current and Exciting Windings for Transverse Differential Protection electric current_d(j) and X_q(j)、G_fThe relation for meeting formula 2 between (j) and the parameter of electric machine.

The wherein r of formula 1_aStator is straight

Leakage resistance, j be plural number imaginary unit, I_fFor Exciting Windings for Transverse Differential Protection electric current, X_d(j) and X_qJ () is should The operational Impedance of generator d-axis and quadrature axis, G under frequency_fJ () is the Exciting Windings for Transverse Differential Protection under the frequency Transmission function；

Formula 2

x_dFor direct-axis synchronous reactance, x '_dFor direct-axis transient reactance, x_d" for the super transient state electricity of d-axis Anti-, T_d' it is d-axis transient time constant, T_d" for the super transient time constant of d-axis, T'_doOpen for stator D-axis transient time constant during road, T_do" the super transient time constant of d-axis when opening a way for stator, x_qFor quadrature axis synchronous reactance, x '_qFor quadrature axis transient reactance, x_q" it is quadrature axis ultra-transient reactance, T_q' For direct transient time constant, T_q" for the super transient time constant of quadrature axis, x_adIt is anti-for d-axis armature Answer reactance, T_DσFor leakage field time constant, the r of d-axis Damper Winding_fFor Exciting Windings for Transverse Differential Protection resistance； Wherein x_d、T’_do、x_q、r_a、x_adFor energy in the measurement test of conventional synchronous generator parameter accurately The parameter of acquisition, it is believed that be known parameters.

For each frequency there are 4 groups of test datas, set up with X_d(j)、X_q(j)、G_f(j) and θ Nonlinear equation, the X under the frequency is obtained after solution_d(j)、X_q(j)、G_f(j).The He of formula 1 All electric parameters of synchronous generator electrical characteristic include x described in formula 2_d、T'_do、x_q、r_a、 x_ad、x′_d、x_d″、T’_d、T_d″、x′_q、x_q″、T’_q、T_q″、r_f、T_Dσ, amount to 15 It is individual, wherein x_d、T'_do、x_q、r_a、x_adFor energy in the measurement test of conventional synchronous generator parameter The parameter for accurately obtaining, it is believed that be known parameters, the d-axis and friendship using 2 pairs of selected frequencies of formula Axle operational Impedance frequency characteristic is fitted, it is possible to obtain select the electric parameter under frequency, Including x '_d、x_d″、T_d'、T_d″、x′_q、x_q″、T_q'、T_q″、r_f、T_Dσ。

The present invention test in need measure data volume mainly have generator unit stator voltage, electric current and Exciting Windings for Transverse Differential Protection electric current.Test measurement equipment be high-precision electrical power system transient recorder, instrument Sample rate at least ensures in more than 2k, the transient state to synchronous generator rest frequency response test Related electric amount carries out whole record ripple record in process and steady-state process, including transient process and steady State process.

Fig. 2 is the flow chart of test method of the present invention, according to the generating that above-mentioned test connection is obtained Machine rest frequency response test data, by the generator unit stator voltage under each frequency, electric current and Exciting Windings for Transverse Differential Protection current testing data bring the nonlinear equation of the foundation of formula 1, the friendship of output generator into D-axis operational Impedance.It is comprised the steps of：

1st, test connection：Motor excitation system to be measured is exited, and Exciting Windings for Transverse Differential Protection loop passes through cable Short circuit, according to test connection wiring is carried out.

2nd, the test data of synchronous motor inactive state under different frequency, the test number are obtained According to including at least generator unit stator voltage, electric current and Exciting Windings for Transverse Differential Protection electric current, final each frequency Three groups of asymmetric stationary rotor status datas, the stationary rotor of one group of three-phase symmetrical can be obtained Status data.

3rd, to set end voltage and electric current in four groups of test datas of different frequency, exciting current Recorder data is filtered, spectrum analysis, and to set end voltage and electric current Park Transformation is carried out, and obtains To ac-dc axis voltage, electric current.

4th, the stator voltage and stator current of each frequency, exciting current be, it is known that according to Formula 1, sets up with X_d(j)、X_q(j)、G_fJ the nonlinear equation of () and θ, is somebody's turn to do after solution X under frequency_d(j)、X_q(j)、G_fJ (), solves the respective asynchronous behavior ac-dc axis of different frequency Operational Impedance X_d(j)、X_q(j)、G_f(j)。

5th, the operational Impedance of three frequencies is selected, is set up with x '_d、x_d″、T’_d、T_d″、x′_q、 x_q″、T’_q、T_q″、r_f、T_DσFor the nonlinear equation of unknown number, wherein x_d、T'_do、x_q、r_a、 x_adThe parameter that can accurately obtain in test is measured for conventional synchronous generator parameter, it is believed that be Know parameter, entered using the d-axis and quadrature axis operational Impedance frequency characteristic of 2 pairs of selected frequencies of formula Row fitting, it is possible to obtain select the electric parameter under frequency, including x '_d、x_d″、T’_d、T_d″、 x′_q、x_q″、T’_q、T_q″、r_f、T_Dσ。

Claims (2)

1. a kind of electrical parameters measure method based on synchronous generator rest frequency response test, It is characterized in that：Comprise the steps of：

A, the test data for obtaining synchronous motor asynchronous operation state under different slip frequencies, institute Test data is stated including at least generator unit stator voltage, electric current and Exciting Windings for Transverse Differential Protection electric current；

B, stator voltage and electric current to different frequency, the recorder data of exciting current are filtered Ripple, spectrum analysis, to stator voltage and electric current Park Transformation is carried out, and respectively obtains ac-dc axis electricity Pressure and electric current；

C, the stator voltage of respective frequencies and stator current, exciting current, the electricity of stator winding Resistance, the synchronous reactance of ac-dc axis are all, it is known that meeting the relation of following equation, solution is different Operational Impedance X of frequency_d(j)、X_q(j) and Exciting Windings for Transverse Differential Protection transmission function G_fJ (), obtains frequency Related characteristic curve；

$\left.\begin{array}{c}{I}_d=\frac{{\mathrm{jX}}_q\left(j\right)+r_a}{-r_a^2+X_d\left(j\right)X_q\left(j\right)-{\mathrm{jr}}_a\[X_d\left(j\right)+X_q\left(j\right)\]}{U}_d\\ I_q=\frac{{\mathrm{jX}}_d\left(j\right)+r_a}{-r_a^2+X_d\left(j\right)X_q\left(j\right)-{\mathrm{jr}}_a\[X_d\left(j\right)+X_q\left(j\right)\]}{U}_q\\ I_f=G_f\left(j\right)I_d\end{array}\right\}$ Formula 1

Wherein r_aStator DC resistance, the imaginary unit of j plural numbers, X_d(j) and X_qJ () is the frequency The operational Impedance of lower generator d-axis and quadrature axis, G_fJ () is the Exciting Windings for Transverse Differential Protection transmission under the frequency Function；

d、X_d(j) and X_q(j)、G_fThe following relation of satisfaction between (j) and the parameter of electric machine

$\left.\begin{array}{c}{X}_d\left(j\right)=\frac{1}{\left\{\frac{1}{x_d}+\left(\frac{1}{x_d^{,}}-\frac{1}{x_d}\right)\frac{{\left(T_d^{,}\right)}^2}{1+{\left(T_d^{,}\right)}^2}+\left(\frac{1}{x_d^{,,}}-\frac{1}{x_d^{,,}}\right)\frac{{\left(T_d^{,,}\right)}^2}{1+{\left(T_d^{,,}\right)}^2}\right\}+j\left\{\left(\frac{1}{x_d^{,}}-\frac{1}{x_d}\right)\frac{T_d^{,}}{1+{\left(T_d^{,}\right)}^2}+\left(\frac{1}{x_d^{,,}}-\frac{1}{x_d^{,,}}\right)\frac{T_d^{,,}}{1+{\left(T_d^{,,}\right)}^2}\right\}}\\ X_q\left(j\right)=\frac{1}{\left\{\frac{1}{x_q}+\left(\frac{1}{x_q^{,}}-\frac{1}{x_q}\right)\frac{{\left(T_q^{,}\right)}^2}{1+{\left(T_q^{,}\right)}^2}+\left(\frac{1}{x_q^{,,}}-\frac{1}{x_q^{,,}}\right)\frac{{\left(T_q^{,,}\right)}^2}{1+{\left(T_q^{,,}\right)}^2}\right\}+j\left\{\left(\frac{1}{x_q^{,}}-\frac{1}{x_q}\right)\frac{T_q^{,}}{1+{\left(T_q^{,}\right)}^2}+\left(\frac{1}{x_q^{,,}}-\frac{1}{x_q^{,,}}\right)\frac{T_q^{,,}}{1+{\left(T_q^{,,}\right)}^2}\right\}}\\ G_f\left(j\right)=\frac{x_{ad}}{r_f}\frac{j\left(1+{\mathrm{jT}}_{D\mathrm{\σ}}\right)}{\left(1+{\mathrm{jT}}_{do}^{\′}\right)\left(1+{\mathrm{jT}}_{do}^{\′\′}\right)}\end{array}\right\}$ Formula 2

X_dFor direct-axis synchronous reactance, X '_dFor direct-axis transient reactance, X "_dFor the super transient state electricity of d-axis Anti-, T '_dFor d-axis transient time constant, T "_dFor the super transient time constant of d-axis, T '_doOpen for stator D-axis transient time constant during road, T "_doThe super transient time constant of d-axis when opening a way for stator, X_qFor quadrature axis synchronous reactance, X '_qFor quadrature axis transient reactance, X "_qFor quadrature axis ultra-transient reactance, T '_q For direct transient time constant, T "_qFor the super transient time constant of quadrature axis, X_adIt is anti-for d-axis armature Answer reactance, T_DσFor leakage field time constant, the r of d-axis Damper Winding_fFor Exciting Windings for Transverse Differential Protection resistance； Wherein X_d、T′_do、X_q、r_a、X_adAccurately to obtain in conventional synchronous generator type approval test Parameter, it is believed that be known parameters；

D-axis operational Impedance and quadrature axis operational Impedance frequency characteristic to acquisition, using formula 2 Carry out curve fitting, export synchronous machine parameter.

2. the method for claim 1, it is characterised in that：Obtain different slip frequencies The test data of lower synchronous motor asynchronous operation state, wherein stationary rotor is motionless at an arbitrary position, Stator side accesses variable-frequency power sources, generator excitation winding short circuit by breaker；It is incorporated into respectively disconnected Two-phase in the device three-phase of road, then breaker three-phase is incorporated into, final each frequency can obtain three The asymmetric stationary rotor status data of group, the stationary rotor status data of one group of three-phase symmetrical.