The relay is based on the spectrum analysis of the generator jump variable compensation algorithm Wang Qingping. Chen Chaoying, Wang Haiji, Liu Yiqing, Liang Lei, Department of Electrical Engineering, Tianjin University. Tianjin 300072 also avoids non-angular devaluation oscillations. The results of the experiment show that the algorithm is widely used in the system of the electrosurgical system and the dynamism of the philosophical process. At the same time, the error compensation method based on the spectrum analysis can also be swallowed up to other fields of system simulation. 1 1 Introduction The electromagnetic transient simulation of synchronous generators is implicitly trapezoidal method. The value is stable, the accuracy is also high, and the error is 3. However, when there is a fault or switching operation in the system, the non-state variables in the network, such as the inductor voltage, capacitor current, etc., jump if the stored power is considered to be continuously changing. + Incoming chamber jump variable metering will cause non-attenuated non-prototype digital oscillations.
At present, the calculation of the jump variable is directly based on the backward Euler method or the damped trapezoidal method. The Euler method has no numerical oscillation but the accuracy is lower than the trapezoidal method, and the error is 022. The accuracy of the damping trapezoid method is between the trapezoidal method and the Euler method. There is still attenuated oscillation between them, and the attenuation speed is related to the damping factor. Therefore, the accuracy of transient simulations that avoid numerical oscillations and high precision is established, from simple inductance. Starting from the capacitive component, the progress has been obtained from the comprehensive model of the synchronous generator jump variable calculation. Based on this, a program is written to simulate the simulation to verify the reliability of the algorithm.
2 Spectrum analysis and 1.1 branch jump variable model 2.I spectrum analysis method for the analysis of the actual system network, especially the voltage and current waveforms of the system components, have a fixed spectrum characteristics. According to this characteristic, the error of the model can be analyzed, and then the total calculation error is set according to the superposition principle. The rolling current in the component is = sinwf+. Substituting the above formula into the component model equation, the mismatch is the frequency of the model. The calculation error of the component. When the excitation contains a plurality of frequency components, the frequency components are superimposed, which is a compensation error.
2.2 The branch variable compensation model of the 乩 branch The back Euler method can effectively prevent the numerical oscillation. Therefore, the Euler method is often used for the calculation of the jump value of the electric quantity. However, the truncation error is large, about, so compensation is needed.
There is 1= for the factory branch road. Apply Euler's method to the ugly step.
Substituting the formula 1 into the right side = 008, can be, for any frequency, the two sides are not equal.
This is due to the fact that there is an imbalance component on both sides of the backward Euler method, which is only related to the algorithm and has nothing to do with the excitation. If the equations are re-matched on both sides, the frequency and components can be accurately calculated. It is known from network analysis. The voltage and current in the component occupy a certain frequency band. There is only one dominant frequency. For example, we make the algorithm accurately calibrate the dominant frequency. It can effectively reduce the overall error. It is desirable to make the dominant frequency a call. , marriage, the game is divided into 50 frequency, the equation is modified so that the dominant component is added to the tank at the dominant frequency, that is, the modified formula of the upper formula is made. It can be changed to the equivalent of the Euler method of the base factory. IX 3.2 Solving the equivalent conductance of the integrated friend mode 6 and the injection current source. It can be seen that the equivalent circuit of the synchronous generator consists of the inductor capacitance and the current source. Therefore, the generator model can be modified by a method similar to the above. In this paper, the type of interface used for synchronous generators is still single. High degree, and there is no need to predict the friendly mode circuit of the school. The method of Document 1 can be obtained when the 1 axis is oscillating. 3 is solved. The equation before the correction is that the inductance friend mode equation can be corrected. For the branch, the same method is applied for error analysis and correction. The ten-class ratio is the electromagnetic voltage of the node voltage; the flat is the flux linkage; the ugly is the step size.
The mining algorithm uses the jump variable of the 3 generator branch mode to calculate the plant surface and takes the axis as an example to derive the generator jump variable comprehensive friend model.
3.1 The simulation equivalent circuit is equivalent to the equivalent conductance 6 and the current source is.
Then the original equation can be reduced to 4, +1 = ice 5 + 1 + Jd, where 掊 7 is the same, so that the equivalent conductance = then the current source is the same, so that the equivalent conductance 6 is injected into the current source = 6, the original The equation can be reduced to +1 where the square = 7 is the same value 屯 and then the injected current source is the pill = 3.3 axis for the admittance and the correction of the current source matrix I3 is sorted out to obtain the Huazhong 15001 system as an example of flight simulation 2 The Gezhouba Phoenix Mountain 37500 line is single-phase short-circuited from Gezhou Trio 46, and the protection action is disconnected after 6,1!8.
Simulate the waveform. 1 is the waveform of the fault recording result converted into the format of the output system of this paper; it is the simulation result of the algorithm; å± is the simulation result of the backward Euler method; it is the simulation result of the damping trapezoid method. In the 1st, not only the simulation accuracy is 1 and the quotient, but the oscillation in the middle is avoided.
The results of the mountain simulation show that the trapezoidal method of 1;1 will produce calves. The numerical value of the attenuation is oscillating; the difference between the initial moments after the commutation of the backward Euler method is large; and the results of the recording method using the compensation method of this paper are also very similar.
Therefore, while the algorithm prevents oscillation, the accuracy is also greatly improved. 5 Conclusion In the electromagnetic transient simulation process of synchronous generator, if the fault occurs, the operation is performed by implicit trapezoidal method. The hopping + will produce a number of oscillating oscillations, while the Euler's law is not accurate, and the wooden text starts from the comprehensive friendly model of the backward Euler method. According to the principle of spectrum analysis. The compensating friend mode equation of the generator is derived. Therefore, it is greatly mentioned that the calculated simulation results of the tip are clear. The algorithm model has good numerical stability, accuracy is much higher than the backward Euler method and effectively eliminates the numerical oscillation. It can be used for the system fault and the electromagnetic transient of the synchronous generator during the switching operation. The 羌 compensation algorithm can also be applied to the jump simulation of other components in the electric system.
The realization of the 4 jump variable simulation algorithm and its example relay base wave and the effective value of each harmonic, the calculation amount is large, when the harmonics in the current are high, and the number of sampling points is larger in each power frequency cycle, the microcomputer is especially Method, the foot protection response violation requires the formula 6 to be much smaller, but as in the previous simulation calculation, it is greatly affected by the non-periodic component, and there is no corresponding correction algorithm. The method proposed in this paper can effectively solve the problem that when the difference between the current sample value and the sample value before the cycle is large, it is considered that there is a non-periodic component and the sample value is corrected.
The outstanding feature of the other methods of the 5-phase component is that it is not designed for any particular algorithm, so it is suitable for all algorithms.
In the microcomputer protection, the method is used to correct the sampled value. Ming, the small non-periodic component of the export of the exchange, its implementation is less. The simulation and the real 1; + application have confirmed the feasibility and effectiveness of this method.
2 Yang Nianci. A segmented parallel filter that corrects the influence of non-periodic components on the Fourier algorithm and its calculation procedure. Power Automation Equipment, 1993, 3.
3 weeks Damin. A method for eliminating attenuated non-periodic components in a recursive Fourier algorithm.
Engaged in the teaching and research work of power system automation relay protection harmonic control; Pan Hua 1966, male, senior engineer, mainly engaged in power system automation relay protection and other aspects of scientific research and production work; Jiang Yaqun 197 women, master, Lecturer, mainly engaged in the teaching and research work of electrical technology, computer protection, electrical measurement and other aspects.
Changed back to date 2001 said 12 power system simulation and its fault analysis research work; Chen Chaoying 1957, male, Ph.D., Ph.D., research direction for power system fault analysis relay protection.
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