JPS59153425A - Controller of braking resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a braking resistance control device that can be applied as one measure for improving the stability of a π1 power system.

[Technical background of the invention and its problems] In recent years, power systems have expanded to 8 m per power generation unit, and due to technical and social factors such as difficulty in obtaining power source Sγ points and securing power transmission routes, large-capacity and long-distance As power transmission becomes necessary, the issue of stable operation of power systems has become a focus of attention.

Several measures have been taken up and researched to improve the stability of this power system, but the systems described here are: One example is the introduction of resistors into power systems.

When a power system failure such as a short circuit or ground fault occurs in the power system, the generator output decreases momentarily. However, the mechanical input torque to the generator remains unchanged immediately after a failure occurs and cannot be controlled rapidly. Due to this, the decrease in machine output is absorbed as mechanical kinetic energy of the generator rotor, accelerating the generator, and if this is left unchecked, a step-out phenomenon may occur.

In such a case, if a braking resistor is installed at or near the generator terminal to absorb and consume the acceleration energy (two-phase power) to the generator rotor, one generator will not reach tax control and the system will can remain stable.

This was applied only once immediately after the occurrence of a failure, and had a significant effect on the stability across A of the first wave of phase difference angle oscillation. After the stability of the first wave is ensured, the system oscillations gradually come to an end due to various braking effects inherent in the power system.

However, if the system in question is interconnected with an external system with relatively weak interconnection, the long-period components of system fluctuations are excited and the long-period components do not converge for a long time, which is a good system operation. An unpleasant problem remained.

In order to solve the above-mentioned problems, a system was invented in which the braking resistance is repeatedly closed and opened.

This force is shown in Figure 1.

In Figure 1, 1 (source 1 at the power transmission end that is subject to bow stabilization)
! Main transformer for machine, 21riJA-1, 3-cut line,
The 4U power line is branched from the 5-key IT + 3, and in order to suppress the car's 11 vibration (opening and closing the two-sided dynamic resistance 6, the 2 and FO [vessels, 7
Nij Depth: Rotation speed detector that detects the rotation speed of machine 1, 8
This is an open side 1 device lf that outputs a control command to the breaker 5. This method if, 'Ai, + Di-: A means for detecting the occurrence of a serious accident, a means for detecting the rotation speed of one aircraft (based on 7f-), and a means for detecting the rotation speed of one aircraft (based on 7f-), and the means to compare with the set value and the results of the previous period comparison.
occurrence of a serious accident;
At the same time, braking resistance 60
This is a control method that repeatedly performs the closing/opening It' control to ensure the degree of safety for the first phase (tau) against the serious accident and to bring the frequency fluctuations of the two systems to an early end.

However, repeatedly closing and opening one breaker in the manner described above is harsh on the breaker. As a result,
The capacity of the braking resistor is divided and installed, and in the event of a serious accident f1, part of the braking resistor is turned on and then released after a certain period of time, while the remaining braking resistor is closed.

A method was also devised to ensure transient stability in response to the previous serious accident by repeatedly performing closing and opening control in response to fluctuations in the rotational speed of the 1p1 transfer gear.

Since it is an FC, it requires a large number of circuit breakers and braking resistance, so it is a rather preferable method.

[Purpose of the invention] The oscillation after the transient stability during a system fault, that is, the first wave of oscillation is maintained, and the normal system operation oscillation can be calculated using the angular velocity of the rotor (
△ω) is detected, closed when △ω>0, and opened when △ω≦0, and the capacity is made variable using a thyristor SW and braking resistor to control the amount of input and obtain appropriate damping. The purpose of this invention is to obtain a control device for braking resistance.

[-Embodiments of the Invention] The present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an embodiment of the braking resistance control device according to the present invention C.

In FIG. 2 In, the same symbols as in FIG. 1 indicate the same devices. In the invention C, the braking resistor 6 is turned on by the thyristor switch 101. Therefore, in the output of the rotation speed detector 7 and the phase control device 9f2, the output fluctuation △ω
(-7"), change the phase control of the thyristor switch IO.
1 or more (△ω〉KO2), the thyristor switch 10
ignition, the braking resistor 6 is connected to the system i2, and the firing angle after the braking resistor 60 is connected is determined by the magnitude of the change in the root rotational speed Δω/Δl. 1 circle α
Continuously change the generator rotation speed △ω to a certain set value ω2
In other words, when the generator rotor energy is sufficiently decelerated, the sirisk switch 10 is gate-blocked and the limit ah M resistor 6 is opened.

When the braking resistor 6 is turned on, the system voltage is set to PBR, E (V
).

Letting the resistance value of the braking resistor 6 be R [Ω], it is well known that 1-t
1, there is the following relationship.

2 PBR=i-K(α) Here, K(α) is the point when a thyristor is used.

It is a conversion coefficient determined by the arc angle 1-.

As shown in the above equation, the braking resistance value is constant, and by changing the firing angle α of the diristor switch 0 (2), the closing capacity of the closing braking resistor can be changed continuously.

FIG. 3 - When the sirisk switch 10 is fired at the firing angle α, the voltage waveform across the braking resistor 6 is as shown in LLi-.

Next (1) The operation will be explained using FIGS. 4 and 5.

FIG. 4 is a diagram showing the output-sum-difference angle of the output tml. Curve A is the initial state (based on 2), curve opening is the state when the system is operated (changed from 2), and curve No. V is the state when the braking resistor is controlled to a certain firing angle and connected.

Now, if the system operation is strengthened, for example by adding a loop or adding a 19] line, the initial operating point A (output PO) will be the instantaneous C
Transfer to point (output A1). Centered on the next stable point B, P
It fluctuates between point D and i-po=PQ-P2. When accelerating again from point D, the phase change arc angle is controlled by the control unit 9 so that the capacitor PBR which requires the braking resistor 6 is reached when △ω>Kωl. The lister switch is ignited, and at that point it moves from the beginning of the curve to curve C, accelerating from point E, and suppressing the width of the oscillation from point E to point F.

Next, when the 52F point is reached, that is, △ω=0, the gate of the control device & 9Iri Zyristor switch IO is blocked, and at the current zero point, the curve is moved to the beginning of the curve again at 111+, making it oscillate from the G point. . Therefore, it is the fluctuation from point G to point H, and ψ
to be suppressed. Furthermore, since the acceleration △ω from point E becomes smaller,
Turning on the braking resistor 6 - Don't do it.

Expressing the above explanation in terms of the relationship between output and time, the 51st
becomes. The curve according to the present invention shows that the power fluctuation is reduced and stabilized compared to the conventional curve E2.

Effects of the Invention As described above, according to the present invention, by controlling the phase of the braking resistor using the Zyristor switch based on the rotational speed deviation of the generator, power fluctuation is reduced and stabilization is achieved. can be done.

[Brief explanation of drawings]

Figure 1 is a system diagram of the electric and power systems with braking resistors installed;
FIG. 3 is a system diagram showing an embodiment of the present invention, FIG. 3 is a waveform diagram of the voltage applied to the braking resistor, and FIGS. 4 and 5 are curve diagrams for explaining the present invention in detail. 1... Generator 3... Bus bar 4... Power system 5... Breaker 6... Braking resistor 7... Rotation speed detector 9... Phase control device River... Thyristor switch agent Patent attorney Kensuke Chika (1 person)Figure 1Figure 3Figure 4AFigure 5

Claims (1)

[Claims] In a power system having at least one generator and power transmission line, estrus, rotational speed deviation of machine, frost, power 1
A braking resistance control method characterized in that the braking resistor is controlled by a xyrisk switch by detecting the 1ili difference signal and using this to control the generator output bus or the transmission line outlet. Device.