JPS5967834A - Reactive power controller - 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 The present invention relates to a voltage reactive power control device when a stepwise changing reactive power supply device and a continuously changing reactive power supply device coexist.

A conventional device of this type is shown in FIG. In the figure, (1) is a transformer with a tap changer, (2) is a high-voltage bus, and (3) is a low-voltage bus, +41 and +51.
is FT.

(6) CT, (71 is a reactive power detector, (8) is a voltage detector, (91 is a voltage reactive power control device, (10-1)
～(10-n) is CB for star controller, (11-1)
~(11-n) is a starcon, 02) CB for Kesyan reactor, (13H shunt reactor, aG is its control device.

Next, the operation will be explained. The continuously changing voltage of the αυ bus (3) of the reactive power supply device is input to the control device via FT tel, and the field current and firing angle are controlled so that the bus voltage becomes VC as per the command value. There is.

On the other hand, the control of the stacon and shunt reactor is
The voltage signal obtained from the voltage of 3) via PT +51 and voltage detector (8) and the reactive power signal obtained via CT [61 and FT +41 and reactive power detector (7) are sent to the control device (9). ), and by determining the deviation from the set value as a pattern, CB (10-1) ~ (10-n) ~
A 02VC cut-off command is issued to control the power to fall within the desired voltage-no-9JJ power range.

When these type 241 controls are mixed, the control of the stacon and shunt reactor plays the role of coarse IAlu, and the continuously variable reactive power supply device plays the role of fine adjustment.

However, if the fine adjustment is being adjusted over a wide range, hunting may occur if these two types of control are performed simultaneously and independently, so one type of control (normally fine adjustment) is given priority and the other control is timed out. It was necessary to take measures such as taking measures after installing the product. Furthermore, even when the control is performed in consideration of the time limit f, the fine adjustment control causes unnecessary fluctuations, as shown in FIG. 3(a) VC. In other words, if we consider the operation when the demand for reactive power changes from the state shown by arrow (a) to the state shown by arrow (b) due to a change in the AC system in Fig. Move to state ■ using the fine adjustment function.

Next, the coarse adjustment a function moves to the state ■, and the fine adjustment @ function again brings the final state ■Vc.

Since conventional devices are constructed as described above, they often suffer from drawbacks such as fear of hunting, stiffness, and unnecessary fluctuations.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional system, and it involves inputting the currently generated reactive power value of the continuously variable reactive power supply device and the limit value as the equipment into the control device. It is an object of the present invention to provide a device that simultaneously determines and controls necessary coarse adjustment and fine adjustment.

An embodiment of the present invention will be described below with reference to the drawings.

@Figure 2 VC, the same reference numerals as in Figure 1 indicate the same or equivalent parts, (I7) is a device for detecting the reactive power value generated by the continuously variable reactive power supply device; A control device 0I is a CT that controls the field current and firing angle based on the output of the power control device (9).

Next, the operation will be explained.

The reactive power signal obtained from PTt41, Cr +61 via the reactive power detector (7) and the voltage signal obtained from PT (51) via the voltage detector (8) are input to the control device (9). In addition, the reactive power signal Q currently generated by the continuously variable reactive power supply device obtained from PT +51 and CT (19 through the reactive power detector 0) is also input to the control device (9).

Upper limit e of reactive power generated by continuously variable reactive power supply device
It is assumed that Qmaxs is the lower limit tQmin, the unit capacity of the star converter or shunt reactor is expressed as eQunit, and the reactive power t required due to fluctuations in the AC system is △Q.

The control device (9) performs necessary tap changer operations and reactive power operations by pattern discrimination. When determining the reactive power, the number of units (n) that satisfies the following formula
f. Decide and issue important commands to n star controllers or shunt reactors.

n-Q unit-(Qc-Qmin)(ΔQ(n
-Qunit+(Qmax-Q(B)),
By performing control that takes into account the margin to the upper or lower limit of the continuously variable reactive power supply device, hunting or unnecessary operations can be avoided even when stepwise elements and continuous elements are mixed. Can be controlled. This is shown in Figure 3(b).
To explain, 31! : When the reactive power required by the flow system changes from arrow (a) to arrow (b) VC, rough fi11
9 Ml &! The function moves to state 0, and at the same time, the fine adjustment function moves to state 7;i;l■.

In addition, in the above embodiment, the stacon and the shunt reactor are all of the same capacity, but it is obvious that the present invention can be applied even if they are not of the same capacity. Furthermore, as a continuously variable reactive power supply device, not only rotary capacitors and SVCs but also power generation products (thyristor application products of various sizes may be used).

Based on the above, according to the invention, by performing control that takes into account the margin to the upper or lower limit of the continuously variable reactive power supply device, 4'λ tuning can be achieved when stepwise elements and continuous elements are mixed. The effect of being able to obtain a voltage reactive power control device that does not cause unnecessary operations or unnecessary operations is f! ! , Kameru.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional device, FIG. 2 is a diagram showing an embodiment of the present invention, and FIG. 3 is a diagram explaining the present invention in detail. In the figure, fi+...transformer, 121, 131
-... Bus line, 141, 151-= FT, isl j
an-c'r, (7), α7) --- Reactive power detector, (8)-@pressure detector, +91 --- Control device, (1
0-1) ~(10-n)c2. (L4)--...breaker, (11-1) ~ (11-n)-xri: I y
, a3... Shunt reactor, 05... Reactive power supply device, ao, Shun... Control device. In Figure A, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In the reactive power control device comprising a first reactive power supply device that supplies reactive power in stages and a second reactive power supply device that continuously supplies reactive power, the reactive power supply device of @2 above. A reactive power control device characterized in that a margin up to an upper limit or a lower limit of the device is determined by measuring the current reactive power output of the device, and this margin is taken into account in a discrimination circuit.