JP5330082B2 - Excitation control device for synchronous generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that much cost and time are required for procurement and transportation of equipment such as a frequency analyzer as well as for connection to an excitation control device, since a synchronous generator is required to be operated concurrently with a power grid 5 in a tuning operation of a grid stabilizing device provided in the excitation control device. <P>SOLUTION: An excitation control device 9 of a synchronous generator 1 having AVR14 and PSS11 includes, in the excitation control device 9, a sine wave output device 17 which generates a sine wave frequency for analysis of frequency response characteristics during operation of the synchronous generator 1 and outputs a calculation signal Op and a test signal Te, and a frequency characteristic analyzer 18 in which the calculation signal output from the sane wave output device and a terminal voltage signal are input for calculating frequency characteristics (k, &theta;) of the terminal voltage signal. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an excitation control device for a synchronous generator to which a system stabilization device is added to improve the stability of an electric power system, and more particularly to an excitation control device for a synchronous generator having a function of analyzing frequency response characteristics.

Usually, a generator connected to an important power system has an automatic voltage regulator (hereinafter referred to as AVR) for keeping the terminal voltage of the synchronous generator constant at a target voltage in an excitation control device, and a target voltage. A system stabilizing device (Power System Stabilizer, hereinafter referred to as PSS) that stabilizes the generator operation by adjusting is provided (for example, see Patent Documents 1-4).
When measuring the frequency response characteristics of the excitation control device, particularly the PSS, a separately configured frequency analyzer is connected to the excitation control device.

FIG. 6 is a diagram showing a circuit configuration of a conventional technique for analyzing a frequency response characteristic of an excitation control device of a synchronous generator by connecting a frequency analyzer to the excitation control device.
6, 1 is a synchronous _{generator, 1 -1 stator 1 -2} is field winding. Then, 2 is a thyristor rectifier for supplying an excitation current to the field winding 1 _-2.

The stator 1-1 of the synchronous generator ₁ is connected to the power system 5 via the main transformer 3 and the circuit breaker 4, and can be operated in parallel with the power system 5. Reference numeral 6 denotes a self-exciting transformer that supplies power to the thyristor rectifier 2. 7 and 8 are an instrument transformer and an instrument current transformer for detecting the output voltage and output current of the synchronous generator, respectively, and the detected voltage and current are input to the excitation control device 9.

The excitation control device 9 is configured so that the output voltage, that is, the terminal voltage of the synchronous generator 1 is maintained at the set value based on the terminal voltage signal and the current signal input from the instrument transformer 7 and the instrument current transformer 8. field is for controlling the amount of excitation windings 1 _-2, and a circuit and a device as described below.

  That is, an analog input converter 10 that includes an A / D conversion processing unit and an arithmetic processing unit, and outputs as a terminal voltage signal VG, an active power signal PG, and a frequency signal FG of digital data based on the input voltage and current, Among the digital data output from the analog input converter 10, the PSS 11 that inputs the active power signal PG and the frequency signal FG and calculates the system stabilization signal Pe, and the voltage target value (set by the AVR voltage setting unit 12) 90R) and the terminal voltage signal VG are calculated, the system stabilization signal Pe is added as an auxiliary input to the deviation, and a test signal Te from a frequency analyzer described later is further added. An adder 13 and an ignition signal are given to the thyristor rectifier 2 in accordance with a signal output from the adder 13 An AVR 14 and a test analog input / output circuit 15 for measuring the frequency characteristics of the terminal voltage signal VG are provided.

  The test analog input / output circuit 15 converts the digital data terminal voltage signal VG output from the analog input converter 10 into analog data and outputs it to the outside, and an external input. An input unit (AI) for converting a test analog signal into digital data is provided.

  Reference numeral 16 denotes a frequency analyzer, which is normally disconnected from the test analog input / output circuit 15 and is output only when the frequency of the terminal voltage signal VG is measured. The terminal voltage signal VG, which is analog data output from (AO), is input. Conversely, a test signal for analog data is output to the input section (AI) of the test analog input / output circuit 15. The input section (AI) of the test analog input / output circuit 15 is connected to the adder 13.

Hereinafter, functions of the conventional excitation control device 9 will be described.
The AVR 14 subtracts the terminal voltage signal VG from the set value (90R) of the AVR voltage setting device 12 to calculate a deviation, and adds the stabilization signal Pe of the PSS 11 to this deviation to obtain the ignition phase angle of the thyristor rectifier 2. adjusted to adjust the amount of excitation of the field winding 1 _-2 synchronous generator 1.

  The PSS 11 is used as an auxiliary input to the AVR 14 of the synchronous generator, and adjusts the electric torque generated by the excitation system to include a braking torque having the same phase component as the change in the rotation speed of the generator, thereby attenuating fluctuations between the generators. To function. The input signal of the PSS 11 includes an active power deviation (ΔP), a rotational speed deviation (Δω), a frequency deviation (Δf), etc. of the generator. In the example of FIG. The frequency deviation (Δf) is calculated from (ΔP) by the frequency signal FG to obtain the stabilization signal Pe.

Next, an outline of the test circuit will be described.
The frequency analyzer 16 inputs the terminal voltage signal VG output from the analog input conversion device 10 and compares it with a test signal such as white noise (white noise) to measure the frequency characteristic of the excitation control device 9. Then, the PSS 11 is tuned based on the frequency characteristics of the excitation control device 9.

JP-A-8-322155 JP-A-9-98600 JP-A-10-052096 JP 2003-330973 A

The conventional technology described above has the following problems to be improved.
That is, when measuring the frequency characteristics of the excitation control device 9, the test signal flowing between the frequency analyzer 16 and the test analog input / output circuit 15 is an analog signal, and therefore the measurement result is an error of the intervening test circuit or a delay circuit. It is easily affected by frequency characteristics. In addition, since the tuning operation of the PSS 11 needs to be performed in a state where the synchronous generator 1 is operating in parallel with the power system 5, procurement of test equipment such as the frequency analyzer 16 manufactured separately from the excitation control device 9. The transportation and connection with the excitation control device 9 required a lot of cost and time.

  Therefore, the present invention eliminates the procurement of test equipment such as a frequency analyzer, transportation, and construction of a test circuit in the prior art, and eliminates the influence of the error in the test circuit and the frequency characteristics in the delay circuit. An object is to provide an excitation control device.

  In order to achieve the above object, the invention according to claim 1 is directed to input means for inputting an output voltage and an output current of a synchronous generator to calculate a terminal voltage signal, an active power signal and a frequency signal, and the input means. Obtained by adding at least the active power signal among the signals obtained by calculating the system stabilization signal and adding the system stabilization signal to the deviation between the voltage target value and the terminal voltage signal. An automatic voltage regulator for controlling the excitation amount of the synchronous generator based on the deviation signal, and a sine based on the frequency for analyzing the frequency response characteristics of the excitation control device in the excitation control device of the synchronous generator A sine wave output device that outputs a calculation signal composed of a wave and a cosine wave, and outputs a signal obtained by multiplying the sine wave by a predetermined gain as a test signal to the automatic voltage regulator, and synchronous power generation And a frequency characteristic analyzer that calculates a frequency characteristic of the terminal voltage signal of the synchronous generator by inputting the terminal voltage signal during the operation of and the calculation signal output from the sine wave output device. To do.

  According to the present invention, since procurement of test equipment such as a frequency analyzer, transportation, and construction of a test circuit are omitted, it is possible to obtain a frequency characteristic that is not affected by an error of the test circuit or a delay circuit. It is possible to provide an excitation control device for a synchronous generator capable of tuning a system stabilizing device according to frequency characteristics.

The block diagram of the excitation control apparatus of the synchronous generator which concerns on Embodiment 1 of this invention. The block diagram of the sine wave output device and frequency characteristic analyzer which concern on Embodiment 1 of this invention. The block diagram of the excitation control apparatus of the synchronous generator which concerns on Embodiment 2 of this invention. The block diagram of the excitation control apparatus of the synchronous generator which concerns on Embodiment 3 of this invention. The block diagram of the sine wave output device and frequency characteristic analyzer which concern on Embodiment 4 of this invention. The block diagram of the prior art which connected the frequency analyzer to the excitation control apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
In the configuration diagram of the synchronous generator excitation control device shown in FIG. 1, the same reference numerals are given to the same parts as those in FIG.

  The main difference between the first embodiment and the prior art in FIG. 6 is that the test analog input / output circuit 15 and the frequency analyzer 16 are removed, and instead the test signal Te and the calculation signal Op for measuring the frequency characteristics are used. The frequency signal is calculated by inputting the test signal Te and the terminal voltage signal VG of the synchronous generator 1 output from the analog input converter (also referred to as input means) 10. And an output device 19 for displaying the gain k and phase θ of the frequency characteristic analyzed by the frequency characteristic analyzer 18 is attached to and detached from the excitation control apparatus 9. It is in the point that it was installed as possible. In addition, you may make it incorporate in the excitation control apparatus 9 by making the output device 19 small.

  The test signal Te output from the sine wave output unit 17 is not always input, and is input to the adder 13 only when the frequency characteristic of the terminal voltage signal is measured. The voltage target value (90R) of the adder 13 and the polarities of various input signals are as follows. That is, the voltage target value (90R) is (+), the terminal voltage signal VG is (−) in order to have a negative feedback amount, the stabilization signal Pe is (+), and the test signal Te is (+).

The outline and operation of the sine wave output unit 17 and the frequency characteristic analyzer 18 will be described below with reference to FIG.
The sine wave output unit 17 inputs a single frequency (ωt) generated by the frequency setting unit 20 to a sine wave generator (sin) 21 to generate a sine wave (sin ωt), and also a single frequency. (Ωt) is input to a cosine wave generator (cos) 22 to generate a cosine wave (cosωt). Among these, the sine wave (sinωt) is adjusted as the gain G by the gain adjuster 23 and output as the test signal Te (G · sinωt). Further, the sine wave (sin ωt) and the cosine wave (cos ωt) are output as calculation signals Op (sin ωt, cos ωt). Incidentally, the frequency (ωt) generated by the frequency setting unit 20 is, for example, about 0.1 [Hz].

  The frequency characteristic analyzer 18 receives the calculation signal Op (sinωt, cosωt) output from the sine wave output unit 17 and the terminal voltage signal VG of the synchronous generator 1 output from the analog input converter 10. By inputting (k · sinωt + θ), the gain k and the phase θ of the frequency characteristic are calculated as follows.

The frequency characteristic analyzer 18 will be described in a little more detail.
The frequency characteristic analyzer 18 includes a digital data calculation signal Op (sinωt, cosωt), a digital data terminal voltage signal VG (k · sinωt + θ) detected by the instrument transformer 7 and output from the analog input circuit 10. , The real part of the terminal voltage signal VG (k · sinωt + θ) with respect to the calculation signal Op (sinωt, cosωt) is calculated by the real part calculator 24, and the imaginary part is calculated by the imaginary part calculator 25. Then, the obtained real part and imaginary part are input to the gain calculator 26 and the phase calculator 27, respectively, and are calculated, thereby calculating the gain k and phase θ of the frequency characteristic from the gain calculator 26 and the phase calculator 27.

The frequency characteristic analyzer 18 performs calculation until the values of the frequency characteristic gain k and phase θ converge, and averages the convergence results. In the averaging process, the gain k and the phase θ are calculated a predetermined number of times, and the average values are calculated. And it becomes possible to calculate the frequency characteristic of an arbitrary frequency band by repeating analysis sequentially about the frequency band set to the sine wave output device 17.
The gain k and phase θ of the frequency characteristic obtained by the averaging process are displayed to the operator by the output device 19 described above.

Next, the operation of the first embodiment will be described.
(I) When frequency characteristics are not measured First, the connection state between the adder 13 and the sine wave output device 17 is disconnected, and the test signal Te (G · sinωt) of the sine wave output device 17 is not input to the adder 13. Put it in a state.

This state is a normal operation state of the excitation control device 9, and the AVR 14 calculates a deviation by subtracting the terminal voltage signal VG from the set value (90R) of the AVR voltage setter 12, and the PSS 11 is stabilized to this deviation. The ignition signal Pe is added to adjust the ignition phase angle of the thyristor rectifier _{2 and} the excitation amount of the field winding 1-2 of the synchronous generator 1 is adjusted.

(Ii) When measuring frequency characteristics (a) The circuit between the PSS 11 and the adder 13 is disconnected.
The test signal Te is input to the adder 13 in a state where the circuit between the PSS 11 and the adder 13 is disconnected, that is, in a state where the stabilization signal Pe is not input to the adder 13.

  The digital data terminal voltage signal VG (k sinωt + θ) output from the analog input circuit 10 is input as an input signal to the frequency characteristic analyzer 18, and the digital data calculation signal Op output from the sine wave output device 17. Also input (sinωt, cosωt).

As a result, during operation of the synchronous generator 1, the voltage setting value (90R) is input to the adder 13 with a positive polarity (+), and the terminal voltage signal VG (k · sinωt + θ) is input with a negative polarity (−). since the test signal Te is input in positive polarity (+), AVR14 exciting the thyristor rectifier 2 two-dot field winding 1 _-2 synchronous generator 1 gives an arc signal in response to these deviations 13e Then, the terminal voltage signal VG of the synchronous generator 1 is controlled to be equal to the voltage setting value (90R).

  At this time, the frequency characteristic analyzer 18 receives the calculation signal Op (sinωt, cosωt) output from the sine wave output device 17 and the terminal voltage signal VG (k · sinωt + θ) of the synchronous generator 1 as described above. 2, the real part imaginary part 25 and the imaginary part computing part 25 compute the real part and the imaginary part, respectively, as shown in FIG. The gain k and the phase θ as frequency characteristics are calculated from the gain calculator 26 and the phase calculator 27 by inputting to the phase calculator 27 and displayed on the output unit 19.

The examiner confirms the gain k and the phase θ at this time, and adjusts the time constant of the phase compensation circuit of the AVR 14, for example, the delay time constant so as to obtain an appropriate phase.
(B) A circuit between the PSS 11 and the adding unit 13 is connected.

  After the adjustment of the parameters of the AVR 14 is finished in (a) above, this time, the output terminal of the PSS 11 and the adder 13 are connected, and the stabilization signal Pe output from the PSS 11 is added to the adder 13 plus (+). Input with polarity. The adder 13 calculates the deviation 13e under this input condition.

  The AVR 14 gives an ignition signal to the thyristor rectifier 2 according to the deviation 13e in the state where the stabilization signal Pe is added, and causes the synchronous generator 1 to generate a voltage. Therefore, the frequency characteristic analyzer 18 receives (feeds back) the terminal voltage signal VG of the synchronous generator 1 in a state where the stabilization signal Pe of the PSS 11 is added to the adder 13.

  The frequency characteristic analyzer 18 calculates the real part and the imaginary part again from the terminal voltage signal VG of the synchronous generator 1 inputted at this time and the test signal Te from the sine wave output device 17, and these real parts The gain k ′ and the phase θ ′ as frequency characteristics are calculated from the imaginary part and displayed on the output unit 19.

  The examiner confirms the gain k ′ and the phase θ ′, which are frequency characteristics when the PSS 11 is connected, and adjusts the setting value of the PSS 11. That is, the gain is increased if the effect is poor, or the time constant of the phase compensation circuit is adjusted if the phase characteristic of the PSS 11 is deviated from the power oscillation frequency.

  In the above description, the sine wave output unit 17 outputs the sine wave signal (sinωt) and the cosine wave signal (cosωt) as the calculation signal Op. However, the sine wave output unit 17 outputs the sine wave as the calculation signal Op. Only the wave signal (sinωt) may be output, and the cosine wave signal (cosωt) may be generated by calculation from the sine wave signal (sinωt) input on the frequency characteristic analyzer 18 side.

  As described above, according to the first embodiment, since the sine wave output device 17 and the frequency characteristic analyzer 18 are built in the excitation control device 9, what is the excitation control device 9 as in the prior art? There is no need to prepare test equipment such as a separately configured frequency analyzer 16, and there is no error or delay due to the test circuit connecting the excitation control device 9 and the frequency analyzer 16 in the prior art. The frequency characteristic of the excitation control device 9 can be obtained in the operating state.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to the block diagram of the synchronous generator excitation control apparatus shown in FIG.
The main difference between the second embodiment and the first embodiment (FIGS. 1 and 2) is that either the terminal voltage signal VG or the active power signal PG obtained from the analog input converter 10 is selected. Thus, the first changeover switch 30 to be output to the frequency characteristic analyzer 18 is provided, and other configurations and operations are the same as those of the first embodiment.

The active power signal PG is an electric quantity obtained based on a sine wave voltage and current, and therefore can be represented by a sine wave. Therefore, in the case of the second embodiment, the apparatus of FIG. 2 can be used as it is simply by replacing the terminal voltage signal VG (k · sin ωt + θ) with the active power signal PG (k ₂ · sin ωt + θ ₂ ) or the like. Here, k ₂ and θ ₂ are a gain and a phase angle.

  In the second embodiment, the terminal voltage signal VG is selected and input to the frequency characteristic analyzer 18 by the first changeover switch 30 as described above. In addition, the frequency characteristic of the active power signal PG can be measured.

(Embodiment 3)
A third embodiment of the present invention will be described with reference to the block diagram of the synchronous generator excitation control apparatus shown in FIG.
The main difference between the third embodiment and the first embodiment (FIGS. 1 and 2) is that a second changeover switch 40 for switching the input destination of the test signal Te output from the sine wave output device 17 is provided. Thus, the input destination of the test signal Te is the adder 13 or the PSS 11, and other configurations are the same as those in the first embodiment.

  In the third embodiment, as described above, the test signal Te from the sine wave output device 17 is input not only to the adder 13 but also to the PSS 11 to measure the frequency characteristics when the PSS 11 is connected in series to the AVR 14. can do.

(Embodiment 4)
A fourth embodiment of the present invention will be described with reference to the block diagram of the sine wave output device and frequency characteristic analyzer shown in FIG.
In the present embodiment, the functions of the sine wave output device and the frequency characteristic analyzer shown in FIG. 2 are enhanced. In FIG. 5, reference numeral 17A denotes all frequencies in the frequency band set as the test signal output device ( is a sine wave output device that outputs a signal obtained by synthesizing ωt,..., iωt,..., nωt), and 18A can simultaneously calculate frequency characteristics at all frequencies set by the test signal output device 17A. This is a frequency characteristic analyzer.

  The sine wave output unit 17A generates a plurality of sine waves (sinωt to sin nωt, where n is an integer) up to a frequency (nωt) that is an integer n times the fundamental frequency (ωt), and adds all the sine waves. Test signal Te (G · sinωt +... + Gi · siniωt +. Is configured to output. Incidentally, the frequencies (ωt) to (nωt) of the frequency setter 20 are, for example, about 0.1 to 10 [Hz].

Further, the frequency characteristic analyzer 18A receives the calculation signal Op (sin ωt to sin nωt, cos ωt to cos nωt) from the sine wave output unit 17A, and the synchronous generator 1 output from the analog input converter 10. enter the terminal voltage signal VG (Vout), calculation signal (sinωt~sin nωt, cosωt~cos nωt) real part calculator 24 ₁ the real part of the input signal (Vout) for, 24 _i, ... 24 _n was calculated by the imaginary part imaginary part calculator 25 _1, 25 _i, computed at ... 25 _n.
Calculated the real and imaginary parts, respectively a gain calculator _{26 1, 26 i, ... 26} n, the phase calculator 27 _1, 27 _i, and input to ... 27 _n, calculates a gain k and the phase θ of the frequency characteristic To do.

  According to the fourth embodiment, when the apparatus composed of the sine wave output device 17A and the frequency characteristic analyzer 18A is applied to the excitation control device 9 shown in FIG. 1, FIG. 3, or FIG. Therefore, the frequency characteristics k and θ at a plurality of frequencies can be measured by a single test, and the inspection efficiency is extremely improved.

1 ... synchronous generator, 1 _{-1 ...} synchronous generator stator winding, 1 _{-2 ...} synchronous generator field winding, 2 ... thyristor rectifiers, 3 ... main transformer, 4 ... breaker, 5 ... power system 6 ... excitation power transformer, 7 ... instrument transformer, 8 ... instrument current transformer, 9 ... excitation control device, 10 ... analog input converter, 11 ... system stabilization device (PSS), 12 ... voltage setting 13 ... adder, 14 ... automatic voltage regulator (AVR), 17 ... sine wave output device, 18 ... frequency characteristic analyzer, 19 ... output device, 20 ... frequency setting device (ωt), 21 ... sine wave output (Sin), 22 ... cosine wave output device (cos), 23 ... gain adjuster, 24 ... real part computing unit, 25 ... imaginary part computing unit, 26 ... gain computing unit, 27 ... phase computing unit, 28 ... addition Part (Σ), 30... First changeover switch, 40... Second changeover switch.

Claims (8)

Input means for calculating the terminal voltage signal, active power signal and frequency signal by inputting the output voltage and output current of the synchronous generator, and system stability by inputting at least the active power signal among the signals obtained by this input means System stabilizing device for calculating the control signal, and automatic voltage for controlling the excitation amount of the synchronous generator based on the deviation signal obtained by adding the system stabilization signal to the deviation between the voltage target value and the terminal voltage signal In an excitation control device for a synchronous generator comprising a regulator,
Outputs a calculation signal composed of a sine wave and a cosine wave based on a frequency for analyzing the frequency response characteristic of the excitation control device, and also outputs a signal obtained by multiplying the sine wave by a predetermined gain to the automatic voltage regulator. A sine wave output device that outputs as a test signal;
A frequency characteristic analyzer that calculates a frequency characteristic of the terminal voltage signal of the synchronous generator by inputting a terminal voltage signal during operation of the synchronous generator and a calculation signal output from the sine wave output unit; An excitation control device for a synchronous generator characterized by the above.   The frequency characteristic analyzer inputs a terminal voltage signal during operation of the synchronous generator and a calculation signal output from the sine wave output device, and calculates a real part and an imaginary part of the terminal voltage signal with respect to the calculation signal. 2. The excitation control device for a synchronous generator according to claim 1, further comprising: a calculation unit that calculates a gain and a phase of frequency characteristics using the calculated real part and imaginary part.   The synchronous generator excitation control device according to claim 1, wherein the sine wave output unit generates and outputs a sine wave having a single frequency or a plurality of frequencies.   The sine wave output unit is configured to output only a sine wave as a calculation signal, and the frequency characteristic analyzer is configured to generate a cosine wave from the input sine wave. Item 4. The excitation control device for a synchronous generator according to any one of Items 1 to 3.   The frequency characteristic analyzer is configured to input the active power signal instead of the terminal voltage signal and calculate a frequency characteristic of the active power signal with respect to the calculation signal. The excitation control apparatus of the synchronous generator in any one of 1-4.   6. The synchronous generator excitation control according to claim 5, further comprising a first changeover switch for switching either the terminal voltage signal or the active power signal output from the input means to input to the frequency characteristic analyzer. apparatus.   Instead of inputting the test signal output from the sine wave output device to the automatic voltage regulator, it is input to the system stabilization device, and the frequency characteristic in the state where the system stabilization device is connected in series to the automatic voltage adjustment device is calculated. The excitation control device for a synchronous generator according to claim 1, wherein:   8. The synchronous generator excitation control device according to claim 7, further comprising a second changeover switch for switching a test signal output from the sine wave output device to the automatic voltage regulator or a system stabilizing device.

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