JPH065999B2 - AC excitation rotating electric machine control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for an AC excitation synchronous machine capable of variable speed operation by variable frequency AC excitation, and particularly to a variable speed pumped storage power generation system and flywheel power generation. The present invention relates to an AC excitation rotating electric machine control device suitable for improving stability of an AC system such as an electric device.

[Conventional technology]

As a conventional technology of an AC excitation generator-motor device, Japanese Patent Publication No.
As described in Japanese Patent Publication No. 7628 and Japanese Patent Publication No. 5-60645, there is known a method of controlling active power and reactive power by controlling the AC exciting current, and it is possible to quickly control while suppressing disturbance and step-out. It is recognized as suitable for an active power adjustment device, a reactive power adjustment device, etc., which require a response.

Further, as the variable speed pumped storage hydroelectric generator, a system in which a cycloconverter is used as a frequency converter for AC excitation and a pump turbine is directly connected to an AC excitation synchronous machine is suitable for frequency adjustment of the power system, It has been announced at the Kansai Branch Union Conference of the Institute of Electrical Engineers of 1994, and a similar system can be found in 1986 National Conference of Electrical Engineers 1
No. 002, or 34 in the March issue of the 1986 issue of The Institute of Electrical Engineers of Japan
Also announced on the page.

On the other hand, a specific measure for coordinating the AC excitation control device and the pump turbine guide vane control device is disclosed in Japanese Patent Application No. 60-
210004, Japanese Patent Application No. 60-210005 and Japanese Patent Application No. 61-99844.

By the way, each of the AC excitation generator-motor devices introduced in the above documents adopts a method of controlling the phase by the amplitude of the AC excitation current with the voltage phase of the AC system as a reference signal.

However, when the above control method is used, the rotation speed may not be kept constant depending on the operating conditions determined by the slip frequency, the active power output, and the reactive power output.

In addition, Japanese Patent Application No. 60-21004 and Japanese Patent Application 60-21005.
As shown in No. 6, even if the AC power generator / motor device controls the effective power output and the turbine guide vane control system controls the rotation speed, the rotation speed may oscillate around the command value. . Along with this vibration, the water pressure of the iron pipe of the water turbine system and the reactive power output may also vibrate.

There is no mention of a method for stabilizing such a phenomenon of unstable rotation speed.

The problem in this prior art will be described with reference to FIG.

In FIG. 5, reference numeral 5 denotes an AC excitation synchronous machine, the armature winding 5a of which has an AC power system (abbreviated as AC system) via a synchronous closing breaker 4, a main transformer 3 and a system breaker 2, respectively. ) 1 is connected.

On the other hand, the AC excitation winding 5b is connected to the AC power system 1 via the frequency converter 6 including the thyristor power converter 8 and the excitation transformer 7 for each phase, and is different from the AC power system 1. It is excited by the alternating current of the frequency.

Reference numeral 9 denotes a phase detector, which functions to obtain an AC excitation frequency signal. Therefore, the voltage transformer 10 and the voltage phase calculator 11 for detecting the system voltage phase θ _ν and the electrical angle of the AC excitation synchronizer 5 are used. Resolver device for detecting the indicated rotation phase θ _γ
12 and a slip phase calculator 13 are included.

Reference numeral 14 denotes an exciting current control device, which determines the amplitude and phase of a three-phase alternating current command that rotates together with a slip phase θ _s obtained by (θ _ν −θ _γ ) by using biaxial current commands I _q and I _d orthogonal to each other. The thyristor firing angle signal so that the excitation winding current of the AC excitation synchronous machine 5 matches the current command.
15 is output to the automatic pulse phase shifter 16 and, as a result, the automatic pulse phase shifter 16 transfers the thyristor power converter 8
The ignition pulse signal 17 of is output.

Here, the current command signal adjusted by the excitation current controller 14 is
It is given by the method described in JP-B-53-7628 and JP-B-57-60645. That is, the control voltage by controlling the active power output by adjusting the current component I _q of the slip phase theta _S and the same phase, adjusting the current component I _d with a slip phase signal theta _S and 90 ° phase difference You can do it.

Here, the active power P and the voltage V output to the AC system 1 are obtained by converting the signals of the instrument current transformer 18 and the instrument voltage transformer 10 into DC signals by the measuring instrument (P, V sensor) 19. It is detected and input to the automatic active power controller (APR) 20 and the automatic voltage controller (AVR) 21.

By the way, in such a system, generally, a prime mover such as a water turbine (not shown) is directly connected to the AC exciter synchronous machine 5, and the rotation speed is controlled within an allowable range of the AC exciter by adjusting the output of the prime mover. There is. However, if the output of the AC excitation synchronous machine 5 becomes too large or too small, the rotation speed may exceed the set range. Therefore, the dead band circuit 24 and slip frequency correction control are performed so that the AC exciting current is corrected when the difference between the output of the system frequency detecting converter 22 and the output of the rotating frequency detecting converter 23 exceeds the setting range. The circuit 25 produces a corrected output command ΔP ₀ , which is output command P
_By superimposing (subtracting) on ₀ , the above-mentioned deviation of the rotation speed does not occur.

[Problems to be solved by the invention]

In the above-mentioned prior art, in the AC excitation generator-motor device, when the active power output of the generator is controlled, no consideration is given to the unstable phenomenon of the rotation speed which may occur depending on the operating conditions. For example, when the AC excitation generator motor is directly connected to the turbine and applied as a variable speed turbine generator, the rotation speed is controlled by adjusting the guide blade opening on the turbine side. However, in this case, the rotation speed periodically fluctuates even in the constant output operation state. This phenomenon is similar to the racing phenomenon that occurs when a conventional synchronous machine (exciting current is direct current) is used as a turbine generator, due to the rattap (dead zone) present in the main pressure distribution valve of the guide blade drive hydraulic servo mechanism. It always occurs.

On the other hand, separately from this, when the AC excitation synchronous machine is subjected to active power control, as shown in FIG. 6, the torque of the generator decreases as the rotation speed increases, while the torque on the turbine side decreases. However, unless the guide vane opening is changed, even if the rotation speed increases, the rotation speed does not decrease so much. Therefore, in this system, the rotation speed becomes unstable.

FIG. 7 is a diagram showing a situation in which the racing of the rotational speed is amplified by the active power control system in such a system.

In addition, this FIG. 7 is an example in which the AC excitation synchronous machine is operating at a speed lower than the synchronous speed No.
Is positive.

Now, as shown in FIG. 7, the opening degree command Yref, which is the output of the guide vane control system, smoothly changes in the direction in which the change in the rotation speed N is suppressed. On the other hand, the actual guide vane opening Y is reduced by the lap of the main pressure distribution valve of the servo system, which is the drive mechanism, when the rate of change of the opening command Yref becomes low, the movement of the opening Y becomes small and the speed N This state continues until the deviation from the command of becomes large. On the other hand, in order to keep the active power output P constant, the AC excitation control system works in the direction of decreasing the torque as the rotation speed increases, thereby decreasing the active current command 1 _q .

As a result, in the conventional technology, when the rotation frequency fluctuation in the steady operation state as described above and the active power output command cycle from the outside match, the rotation speed greatly changes due to resonance, and accordingly, There was a problem that the rotation speed range was restricted by the setting range of the slip frequency, and the swing range of the practical active power command had to be suppressed. Further, in such a resonance state, the iron pipe water pressure of the long-distance system and the output current effective value of the frequency converter for AC excitation also vibrate at the same cycle, so in the prior art, there is a risk that the iron pipe will be damaged by excessive water pressure. However, there is a problem that the frequency converter may be in an overcurrent state.

An object of the present invention is to provide an AC excitation rotary electric machine control device capable of controlling the rotation speed sufficiently and stably while allowing the active power output of the AC excitation generator-motor device to quickly follow the command. It is in.

[Means for solving problems]

The above object is achieved by adding phase lead compensation to the slip frequency signal equal to the difference between the AC excitation armature voltage frequency and the rotation frequency, and causing it to act on the active power control system in the direction of suppressing the rotation speed fluctuation or the system frequency fluctuation. To be done.

[Action]

As a result of the phase lead compensation being applied to the slip frequency signal,
The operation of the active power control system is provided with a damper function that helps suppress the rotation speed fluctuation, and the rotation speed fluctuation can be eliminated.

〔Example〕

Hereinafter, the AC excitation rotating electric machine control device according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of the present invention. In the drawing, reference numeral 26 is a compensation signal generating circuit, and the others are the same as those in the conventional example of FIG.
Therefore, in order to avoid duplication, the description of the parts described with reference to FIG. 5 is omitted.

The compensation signal generation circuit 26 is composed of an incomplete differentiation circuit as shown in the figure, and has a function of receiving the slip frequency signal fs as an input and outputting a compensation signal ΔP ₁ to which phase lead compensation is applied.

The compensation ΔP ₁ thus created is the correction output command ΔP
With _0, it is superimposed (subtracted) to the output command [Delta] P _0, APR
It is input to 20 and is reflected by the active current command I _q . Note that, here, the output command P ₀ , the correction output command Δ
Both P ₀ and the compensation signal ΔP ₁ are positive in the direction of increasing the power generation output.

Next, the operation of this embodiment will be described.

Since the compensation signal generation circuit 26 performs the incomplete differentiation operation as shown in the figure, when the rotation speed of the AC excitation synchronous machine 5 and the frequency of the AC system 1 are constant, the compensation signal ΔP ₁ is obtained by phase lead compensation. Therefore, the active power control system generates the horizontal axis current command I _q so as to follow only the output command P ₀ from the outside as in the conventional example.

By the way, since the horizontal axis current command I _q changes substantially in proportion to the generator torque of the AC excitation synchronous machine 5, even if the output command P ₀ is constant, the torque tends to decrease as the rotation speed N increases. , The current command I _q decreases.

Therefore, as it is, as in the conventional example, when viewed from the prime mover directly connected to the AC excitation synchronous machine 5, the active power control system operates so as to increase the rotational speed change, resulting in instability.

On the other hand, if the rotation speed N of the AC excitation synchronous machine 5 changes, the slip frequency fs also changes. For example, when the rotation speed N is increasing, the slip frequency fs is decreasing.

In this embodiment, since the slip frequency fs is input to the compensation signal generation circuit 26, the compensation signal ΔP ₁ to which the phase advance compensation is applied is output, and this is the AP.
It affects the active current command I _q by R20, and for example, as described above, while the slip frequency fs is decreasing, the horizontal axis current is increased in the direction of increasing the generator output of the AC excitation synchronous machine 5 by the phase advance repair. An effect of changing the command I _q appears, and therefore, according to this embodiment, the active power control system also has the function of suppressing the rotation speed fluctuation, and as a result, the rotation speed N exhibits an unstable characteristic. Can be effectively suppressed, and the stability can be sufficiently enhanced.

Then, according to the embodiment of FIG. 1, the slip frequency fs
The compensation signal ΔP ₁ = 0 under the operating condition in which is kept constant, and at this time, there is an effect that the active power output is not affected at all.

Next, another embodiment of the present invention will be described.

First, in the embodiment of FIG. 2, the slip frequency signal fs is input to the phase advance compensation signal generation circuit 27, and the compensation signal generation circuit 27
The output of 27 is set as a compensation signal ΔI _q , which is superposed (subtracted) on the horizontal axis current command I _q which is the output of the active power control device 20. In the embodiment shown in FIG. 2, a primary phase advance / delay circuit is applied as the phase advance compensation signal generation circuit 27.

According to the embodiment of FIG. 2, the unstable rotation speed By setting so as to fall within the range, it is possible to effectively suppress the vibration of the rotation speed.

In this embodiment, the compensation signal ΔI _q does not become 0 even in the case of the vibration frequency ω <ω ₂ , but since the feedback of the integral gain of the automatic active power control device 20 forming the outer loop works, the active power output is commanded. The deviation can be controlled to zero. Here, as the phase lead compensation signal generating circuit 27, an incomplete differentiating circuit can be used as in the embodiment of FIG.

Next, in the embodiment shown in FIG. 3, the slip frequency fs is input to the band pass filter 28, and the rotational speed fluctuation component determined by the operating condition is left, and the phase lead compensation signal generating circuit 26 and the proportional element 29 are used to automatically enable It is configured to be superimposed (subtracted) on the input of the power control device 20, and at this time, the pass frequency band of the bandpass filter 28 is changed according to the active power command P ₀ . This uses that the fluctuation period of the rotation speed is almost determined by the active power command P ₀ .

According to the embodiment shown in FIG. 3, only the variation of the slip frequency fs can be taken out by the bandpass filter 28, so that the phase advance compensation signal generating circuit 26 and the proportional element 29 are obtained.
It has the effect of increasing the gain and improving the stabilization function.

Further, in the embodiment shown in FIG. 4, only the rotation frequency signal fr obtained by inputting the output of the resolver device 12 to the frequency converter 23 is input to the phase advance compensation signal generating circuit 26 as it is. In accordance with this, the correction output command ΔP
_{0 is} also obtained from this signal fr. This embodiment operates in the same manner as the embodiment of FIG. 1 when the AC system frequency is constant.

According to the embodiment of FIG. 4, there is an effect that the detection of the system frequency becomes unnecessary and the configuration is simplified. In particular, it is suitable for a generator-motor device having a relatively small capacity compared to the system capacity.

〔The invention's effect〕

According to the present invention, it is possible to suppress fluctuations in the rotation speed that may occur with active power control of an AC excitation synchronous machine. Therefore, an unstable phenomenon of the rotation speed that occurs depending on operating conditions in a pumped storage power generation system or the like. Has the effect of stabilizing. Further, there is an effect of suppressing the rotation speed vibration generated by the interference with the speed control device on the side of the prime mover.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an AC excitation rotary electric machine control device according to the present invention, and FIGS. 2, 3, and 4 are block diagrams showing another embodiment of the present invention, respectively. FIG. 6 is a block diagram of a conventional example, FIG. 6 is a characteristic diagram showing the relationship between generator torque and water turbine torque during active power control, and FIG. 7 is a characteristic diagram for explaining rotational speed fluctuations. 1 ... AC power system, 2 ... System breaker, 3 ... Main transformer, 4 ... Synchronous closing breaker, 5 ... AC excitation synchronous machine, 6 ... Frequency converter, 7 ... Excitation transformer Bowl, 8 ...
… Thyristor power converter, 9 …… Phase detector, 10 ……
Voltage transformer, 11 …… Voltage phase calculator, 12 …… Resolver device, 13 …… Slip phase calculator, 14 …… Excitation current control device, 16 …… Automatic pulse phase shifter, 18 …… Current transformer, 19 ...
... Measuring instrument (P, V sensor), 20 ... Automatic active current controller (APR), 21 ... Automatic voltage controller (AVR), 22
...... System frequency detection converter, 23 …… Rotation frequency detection converter, 24 …… Dead zone circuit, 25 …… Slip frequency correction control circuit, 26 …… Compensation signal generation circuit, 27 …… Phase advance correction signal generation Circuit, 28 …… Band pass filter, 29 …… Proportional element.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Shiozaki 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Shigehiro Kasugawa 3-chome, Saiwaicho, Hitachi, Ibaraki No. 1 Hitachi Ltd., Hitachi Works (72) Inventor Hiroto Nakagawa 3-3-22 Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Kansai Electric Power Co., Inc. (56) Reference JP-A-63-274400 (JP) , A) JP-A-63-95900 (JP, A)

Claims (5)

[Claims] 1. An AC excitation synchronous machine having an armature winding connected to an AC power system and an excitation winding adapted to supply AC excitation power from the AC power system via a frequency converter. In the AC excitation rotary electric machine control device of the method of controlling the active power output of the AC excitation synchronous machine according to the slip frequency represented by the difference between the frequency of the AC electric power system and the rotation frequency of the AC excitation synchronous machine, A compensating signal generating circuit for generating a compensating signal by giving lead phase compensation to a signal representing the slip frequency is provided, and the control by the compensating signal is superimposed on the output control of the active power performed according to the slip frequency. An AC excitation rotating electrical machine control device characterized by the above. 2. A compensation signal generating circuit according to claim 1, wherein the compensation signal generating circuit is an incomplete differentiation circuit which receives the slip signal as an input, and the compensation signal which is the output is subtracted from the active power output command. An AC-excited rotary electric machine control device having the following configuration. 3. The compensation signal generating circuit according to claim 1, wherein the compensation signal generating circuit is a first-order phase displacement circuit to which the slip signal is input, and the output of the compensation signal controls the active power output. An AC-excited rotary electric machine control device configured to be subtracted from a horizontal axis current command. 4. The AC excitation rotation according to claim 2, wherein the input of the slip signal to the incomplete differentiation circuit is configured to be performed through a bandpass filter. Electric machine control device. 5. An AC-excited rotary electric machine control device according to claim 2, wherein the slip signal is calculated by assuming that the frequency of the AC power system is constant. .