JPH01308198A - Excitation controller for synchronous machine - Google Patents

Abstract

PURPOSE:To control an effective stabilization for all various fluctuated frequency components by generating the control target value of ideal effective power in a state stability from a power system fluctuation signal, and closed loop feedback-controlling to follow the effective power to the target value. CONSTITUTION:A deviation epsilon1 between the terminal voltage Vg of a synchronous machine 1 and a set voltage value Vref is calculated. Further, a deviation P between an effective power target value Pref generated by an effective power target value generator 15 on the basis of the terminal voltage and output current of the machine 1 and an effective power P is calculated. The deviations epsilon1 and AP are added, and applied to an automatic pulse phase unit 14. Here, the generator 15 detects the inner phase angle delta of an inner induced voltage with the terminal voltage and the output current, and generates an ideal control target value of the effective power on the basis of the angle delta. Thus, a stable control can be always conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an excitation control device for a synchronous machine, and more particularly to an excitation control device for a synchronous machine suitable for improving the steady-state stability of a multi-machine power system.

[Conventional technology]

Conventional devices attempt to achieve optimal characteristics by selecting blocks according to the system configuration and load condition, as described in Japanese Patent Application Laid-Open No. 61-1.5599, but the parameters Since the change occurs in a stepwise manner, it is not always possible to obtain optimal control characteristics, and if the system configuration or operational status exceeds expectations, there are problems such as unstable control.

[Problem to be solved by the invention]

1. The conventional technology only achieves steady-state stability by open-loop control using fixed gain and phase constants set for a pre-assumed system configuration. Optimum control of the system operation status cannot be performed, and if the actual system operation status deviates from the assumed system status, steady-state stability may be lost and control may become unstable; There was a problem in that effective stabilization control could not be performed for all the various frequency components of a real multi-machine system.

An object of the present invention is to provide a circuit that generates an ideal control target value P ref of active power P for steady state stability in order to always achieve optimal stability in response to changes in system conditions. By setting the control target value P ref and performing closed loop feedback control to make the active power P follow this control target value P ref,
The object of the present invention is to provide an excitation control device that achieves steady-state stability that is effective for all various oscillation frequency components without depending on the operational status of an actual system.

[Means to solve the problem]

In order to achieve the above object, in the synchronous machine excitation control device according to the present invention, the field amount of the synchronous machine is determined in response to a deviation signal between the terminal voltage of the synchronous machine and the set terminal voltage, and the terminal voltage is adjusted. The terminal voltage constant control device is provided with a power system oscillation signal detection means for detecting a power system oscillation signal indicating an oscillation state of the power system connected to the synchronous machine; active power target value generating means for generating an active power target value output by the synchronous machine; active power detecting means for detecting the active power output by the synchronous machine; and a correction means for generating a correction signal, and adds the correction signal to the deviation signal.

Further, the power system fluctuation signal detected by the power system fluctuation signal detection means is at least one of the terminal voltage of the synchronous machine, the armature current, the field voltage, the field current, the frequency, the rotor shaft position, and the shaft speed. Good.

Furthermore, it is preferable that the active power target value generated by the active power target value generation means is composed of a weighted addition of an internal phase difference angle component of the synchronous machine and a time differential value component of the internal phase difference angle component.

The correction means separates the active power detected by the active power detection means into an internal phase difference angle component of the synchronous machine and a time differential value component of the internal phase difference angle component, and separates the active power detected by the active power detection means into an internal phase difference angle component of the synchronous machine and a time differential value component of the internal phase difference angle component. It is preferable to generate a correction signal corresponding to the deviation from the component.

[Effect]

In the synchronous machine excitation device configured as described above, the power system oscillation signal detection means detects the power system oscillation signal indicating the oscillation state of the power system to which the synchronous machine is connected, and the active power target value generation means Generating an active power target value output by a synchronous machine suitable for measuring the steady-state stability of the power system from the system oscillation signal, and an active power detection means detecting the active power output from the synchronous machine, The correction means generates a correction signal corresponding to the deviation between the active power target value and the active power, and applies the correction signal to the field of the synchronous machine in accordance with the deviation signal between the terminal voltage of the synchronous machine and the set terminal voltage. In addition to the deviation signal of the terminal voltage constant control device which determines the amount of magnetism and controls the terminal voltage, it works to improve the steady state stability of the power system.

The power system oscillation signal detection means detects at least one of the terminal voltage, armature current, field voltage, field current, frequency, roller shaft position, and shaft speed of the synchronous machine as the power system oscillation signal.

Further, the active power target value generation means performs a weighted addition operation of the internal phase difference angle component of the synchronous machine and the time differential value component of the internal phase difference angle component as the active power target value.

Furthermore, the correction means separates the active power detected by the active power detection means into an internal phase difference angle component of the synchronous machine and a time differential value of the internal phase difference angle component, and separates each component and each component of the active power target value. A correction signal corresponding to the deviation between the two is generated and output.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a diagram showing the overall configuration of a static excitation device using a thyristor according to an embodiment of the present invention.

In FIG. 1, the static excitation device has a voltage Vg obtained by stepping down the terminal voltage of the synchronous machine 1- by an instrument transformer PT6, and a voltage setting device (
The deviation F0 from the voltage setting value Vref from 9OR) 12 is detected, and the deviation ε1 is amplified by the amplifier 13, and the automatic pulse phase shifter A and pps 14 generate pulses for controlling the thyristor, thereby controlling the excitation power source. Transformer EX,
The excitation power obtained through T R2 is connected to thyristor 2Q.
This is a device that controls the field voltage Vf of the synchronous machine 1 and the synchronous equipment terminal voltage Vg to be constant.

Furthermore, in order to improve system stability, an active power target value generation circuit (active power target generation means) inputs the output voltage and current of the synchronous machine 1 via the instrument transformer PT6 and the instrument current transformer CT5. 15. Active power detection circuit (active power detection means)
At step 19, the active power target value Pref and the active power P are detected. This signal is properly gain and phase corrected, and the power deviation Δ
The output V pss, which has been gain- and phase-adjusted so that P = P ref - P becomes zero, is given as an auxiliary signal to a signal addition circuit for an automatic voltage regulator.

The synchronous machine 1 is connected to a power transmission line 10 via a main transformer 7 , a main breaker 8 , and a system breaker 9 .

Similarly, a power system network 11 consisting of a plurality of synchronous machines
are connected to form a multi-system power system.

First, the active power target value generation circuit J5 is an instrument current transformer CT.
5. Internal induced voltage detection circuit 16 which inputs current and voltage from instrument transformer PT6 and detects internal phase difference angle δ of internal induced voltage Eq; It consists of a braking force coefficient setting circuit 17 and a braking force coefficient setting circuit 18 which differentiates the internal phase difference angle δ with respect to time and sets the braking force coefficient to this time differentiated signal ω=δ. By weighted addition of , the effective power P
The active power target value P ref is generated.

P ref '= Ka δ + ω- (1) Of the active power target value P ref, the component proportional to the internal phase difference angle δ is the synchronization force component, and the component proportional to the time differential signal ω is the braking force component. becomes. The ratio of these components is the synchronization force coefficient,
and the braking force coefficient can be arbitrarily set by changing the gain of , so the active power target value P ref , that is, the ideal value of the active power P according to the specifications from the system stabilization required for Plan 1 to Control target values can be easily determined.

The active power target value P rcf determined in this way is
This is the optimal signal to control when oscillation occurs between the "synchronous machine" and the power system 11 connected thereto.

Next, using this active power target value P ref as a reference signal,
Determine the deviation ΔP-Pref-P from the active power output P. The gain and phase of this ΔP are adjusted in the phase adjustment circuit 20 so that ΔP becomes zero, and the obtained signal pss is applied to the signal addition circuit of the automatic voltage regulator.

The output V pss is the amplifier 13, automatic pulse phaser 14
, thyristor 3, and field circuit breaker 4 to change the synchronous machine field voltage Vf and terminal voltage Vg, and perform closed-loop control so that the synchronous machine active power P matches the active power target value P ref. By matching the active power P with the active power target value P ref, the synchronization component and braking force component included in the active power P can be controlled to match the design target value of 1, K4, so that the design target is always met. towards grid stabilization”
You can achieve the second.

Next, the operation of this embodiment will be explained using FIG. 2. Second
The figure is a detailed block diagram of FIG. 1.

In FIG. 2, the active power target value generation circuit 15 calculates and detects the internal induced voltage Eq from the terminal voltage Vg and current Ic of the synchronous machine 1 in the internal induced voltage detection circuit 16a.

Here, the internal induced voltage Eq is Eq = Va+ j x q Ia3: complex number Xq: synchronous machine q-axis synchronous reactance, and the phase of the internal induced voltage Eg corresponds to the internal phase difference angle δ of the synchronous machine 1.

Next, the internal phase difference angle δ of the internal induced voltage Eq is determined by the phase detection circuit 1.
6b, and further calculates the internal phase difference angle δ. These δ and ω are added with the gain-adjusted values in the coefficient setting circuits 17 and 18b, respectively, and this is calculated as the active power target value P re
Let it be f. Also, the active power P of the synchronous machine] is the terminal voltage Vg
and the current Ig is detected by the power converter 19. A deviation signal Δ between the active power target value P ref and the active power P is determined, and this ΔP is used to correct the excitation device transfer function GAVR(S) 27 and the field circuit time delay of the synchronous machine using the phase adjustment circuit (correction means) 20. The output Vpss is given to the exciter signal addition circuit. Here, the phase adjustment circuit 20 includes a DC component removal circuit 24, a gain/phase adjustment circuit 25, and an output limiter circuit 26. First, the DC component removal circuit 24 is provided to remove the DC component since the signal necessary for system stabilization is the temporal change in ΔP and the DC component is unnecessary. Next, the gain/phase adjustment circuit 25 corrects the time delay of the excitation device and the synchronous machine field circuit, and the active power target value generation circuit 1
s and active power detection circuit 19, gain phase adjustment circuit 25
, exciter transfer function G AVII (S) 27, and the purpose of stabilizing the closed loop control system consisting of the synchronous machine 1.

The output V pss of the phase adjustment circuit 20 is connected to the synchronous machine field voltage Vf and the terminal voltage V through the signal addition circuit of the excitation device.
By changing the lightning current g, the active power P is set to the active power target value P.
Closed loop tracking control is performed to match ref. As a result, the synchronization force and braking force included in the active power P can be controlled to the specified value Ki, and the oscillation of the synchronous machine 1 can be quickly brought to an end, improving system stability. can.

FIG. 3 shows the active power P detected by the active power detection circuit 19.
The internal phase difference angle component δp contained in A circuit 20a for adjusting gain and phase.

20b is a block diagram of a phase adjustment circuit 2o.

Similarly to the above, the output Vpss of the phase adjustment circuit 20 changes the synchronous machine field voltage Vf, the terminal voltage Vg, and the current g through the signal addition circuit of the excitation device, and changes the synchronization power contained in the active power P. By performing closed-loop follow-up control so that the braking force matches what is included in the active power target value P ref, it is possible to further improve system stability.

Next, when the effective power P is controlled to Pm, δ0, and ω, the effect is as follows. The equation of motion of the synchronous machine 1 can be expressed by M: permeability constant Pm: motor output and a secondary oscillation system, so by substituting this into. The eigenvalue α of this equation can be determined, and it can always be made stable.

Furthermore, by keeping the synchronization force constant, the natural frequency of the system can be kept constant.

The above functions are shown in block diagrams in FIGS. 4 and 5.

FIG. 4 shows a simplified block diagram of the actual system. The active power P shown here becomes the output via the complex transfer function Ge(s) of the power system, synchronous machine, excitation device, etc., and the synchronization force and braking force are not controlled values, so the operating state In some cases, it becomes unstable. On the other hand, according to FIG. 5 to which this embodiment is applied, the effective power P is controlled to be Pm, δ+, and ω, so it does not depend on the operating state of the synchronous machine, the system configuration, etc. However, it is possible to always maintain a constant value, thereby improving system stability.

In this embodiment, the internal phase difference angle δ is determined from the internal induced voltage Eq, but other signals that directly indicate the actual rotor shaft position, shaft speed, and motion state of the synchronous machine may also be used. In addition, the internal phase difference angle δ is determined by the synchronous machine field voltage Vf and the field current If.
Rf : Synchronous machine field resistance 1"dz' : Synchronous machine load time field time constant Xd : Synchronous machine direct axis synchronous reactance xd' : Synchronous machine direct axis transient actance, so this You may also use

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

Since the actual active power P of the synchronous machine can be controlled to match the active power target value P ref generated to match the specified braking 1-lux component and synchronization 1-lux component, the operating status of the synchronous machine and the system Regardless of configuration changes and the type of exciter used, system stability with specified specifications can always be ensured.

Furthermore, since closed-loop follow-up control is performed to match the active power P to the active power target value P ref, it is almost unaffected by external factors such as the operating status of the synchronous machine and changes in the system configuration, so the constant settings are very easy. This makes it extremely easy to make adjustments during test runs.

Furthermore, both the active power target value P ref and the active power P equally contain a signal due to the influence of the mechanical output Pm of the turbine output, and furthermore, the difference signal Pref
-P is used as a control signal, so it is not affected by Pm. Therefore, turbine high speed valve control (EVA:
Even when control is used in conjunction with the control that greatly changes the turbine output Pm when a system fault occurs, such as in the case of Earl, Y Valve Actuation), stable stabilization control can always be performed without being affected by the turbine output Pm.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a synchronous machine excitation control device according to an embodiment of the present invention, FIG. 2 is a detailed block diagram of FIG. 1, and FIG. 3 is a block diagram of a phase adjustment circuit according to another embodiment. , FIG. 4 is a block diagram showing a synchronous machine as a secondary vibration system, and FIG. 5 is a block diagram in which a control block of an embodiment according to the present invention is added to FIG. 4. 1...Synchronous machine, ]1...Power system network I network, 1
5 - Active power target value generation circuit, 16... Internal induced voltage detection circuit, 17 - Synchronization force coefficient setting circuit, 18... Braking force coefficient setting circuit, 19 Active power detection circuit, 20...
Phase adjustment circuit.

Claims (1)

[Scope of Claims] 1. A synchronous machine comprising a terminal voltage constant control device that determines the field amount of the synchronous machine in response to a deviation signal between the terminal voltage of the synchronous machine and a set terminal voltage and controls the terminal voltage. In the excitation control device, a power system oscillation signal detection means for detecting a power system oscillation signal indicating an oscillation state of a power system connected to the synchronous machine; active power target value generation means, active power detection means for detecting the active power output by the synchronous machine, and correction means for generating a correction signal corresponding to a deviation between the active power target value and the active power. A synchronous machine excitation control device, comprising: adding the correction signal to the deviation signal. 2. The power system oscillation signal detected by the power system oscillation signal detection means is based on at least one of the terminal voltage, armature current, field voltage, field current, frequency, rotor shaft position, and shaft speed of the synchronous machine. The synchronous machine excitation control device according to claim 1, characterized in that: 3. Claim characterized in that the active power target value generated by the active power target value generation means is comprised of a weighted addition of an internal phase difference angle component of the synchronous machine and a time differential value component of the internal phase difference angle component. 1. The synchronous machine excitation control device according to 1. 4. The correction means separates the active power detected by the active power detection means into an internal phase difference angle component of the synchronous machine and a time differential value component of the internal phase difference angle component, and calculates the respective components and the active power target value. 2. The synchronous machine excitation control device according to claim 1, wherein a correction signal corresponding to a deviation from a component is generated.