JPS6059926A - Voltage reactive power regulator - 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 is based on the primary input voltage of a substation transformer by controlling the operation amount (on/off operation amount) of phase adjustment equipment such as a shunt reactor or a power capacitor. This invention relates to a voltage/reactive power adjustment device that adjusts the voltage within a dead band centered on all values.

Conventionally, in this type of equipment, the reference value when adjusting the primary side input voltage of the transformer within a predetermined dead band is set so that transmission losses are minimized based on the load and system configuration expected at the time of design. As a result, the primary side input voltage of the transformer is appropriately adjusted unless there is a major change in the load or system configuration during actual operation.

However, due to, for example, a shutdown of a generator at a power plant, a decrease in the reactive power adjustment ability due to phase adjustment equipment at a substation, or an unexpected increase in the amount of load other than reactive power, the supply of reactive power to the primary system may be interrupted. If there is a surplus or deficiency that exceeds the expected amount,
The input voltage on the primary side of the transformer cannot be maintained within the total dead zone, resulting in increased power transmission loss due to voltage drop and damage to power transmission and substation equipment due to overload or voltage rise.

Conventionally, when such a situation occurs, it has been configured to be dealt with by automatic voltage adjustment equipment of a power plant that is an upper system of the relevant substation, or by a voltage/reactive power adjustment device of an upper substation.

However, if the configuration is such that the adjustment capacity is sequentially transferred to the upper power system, when the adjustment capacity of the upper power system reaches its limit, the functions of the lower power system will completely stop, resulting in a loss of reliability. The present invention was made to solve these problems, and its purpose is to maintain the lower side of the substation even if the load and system configuration are significantly different from the expected ones. It is an object of the present invention to provide a voltage/reactive power adjusting device that can completely prevent the occurrence of a situation such as a stoppage of the functions of an electric power system.

The present invention corrects the reactive power reference value when adjusting the transformer primary side input voltage within the total dead zone according to the deviation between the current value of the transformer primary side input voltage and the reference value, and makes this correction. The operation amount interest rate of the opposing equipment based on the value! However, when the primary side input voltage of the transformer converges within the dead band, the reactive power passing through the transformer at this time is set as a new reactive power reference value, and the transformer 1
The above object is achieved by appropriately adjusting the next-side input voltage according to the reactive power adjustment device of each substation.

Hereinafter, based on the illustrated example, the original F! I8J will be explained in detail. The drawing is a block diagram showing an embodiment of the main part of the present invention. In the figure, 1 is a primary voltage reference value holding circuit that maintains the reference value Vsi of the primary side input voltage Vi of the transformer, 2 is a primary voltage dead band holding circuit that maintains the input voltage Vi's dead band "DZ", and 3 is a transformer. The primary side input voltage Vi of the device is compared with its reference value Vs, and when the conditions of ■i>■D2 are met, it outputs a comparison result signal F indicating this? A comparison circuit that outputs the deviation signal ΔV (=V 1 - Vs) k, 4 is a dead zone based on the comparison result signal F.
This is a timer that outputs a pulse signal Gi when the input voltage Vi exceeding Dzv11 continues for a predetermined period of time. in this case,
The timer 4 is reset by the pulse signal G and starts the full timekeeping operation again. 5 is a peak hold circuit that extracts and holds the maximum value ΔV' of the deviation signal Δ■ output from the comparator circuit 3. The maximum value ΔV' is reset when a new comparison result signal F or pulse signal G is generated. After this reset, the maximum value ΔV' of the deviation signal Δ■ is extracted until the next new comparison result signal F or pulse signal G is generated.

6 is a reactive power reference value holding circuit that maintains the reference value Qst of the reactive power Q passing through the rotator, and 7 is the generation of reactive power Q necessary to recover the unit variation of the input voltage Vi at each substation. A ratio measurement aKt representing the burden of the amount or consumption amount is maintained by a proportional constant holding circuit, and the proportional constant in the case of starvation is determined according to the capacity of the harmonizing equipment at each substation. 8 is based on the reference value Qs of the reactive power Q, the proportionality constant, and the maximum value ΔV' of the υ deviation signal.
) is an arithmetic circuit that calculates the reactive power correction value QsN'.

The correction value QSN calculated here is the reactive power adjustment ring (
(not shown) to turn on and off the harmonizing equipment.

Q8N=Qs10K・ΔV′・・・・・・(1) Next, 9
is a reactive power dead zone holding circuit that maintains the dead zone QDZ of reactive power Q, 1o is reactive power correction value Q8N + dead zone QD2
and current reactive power input. Receives i, reactive power input Q
a comparison circuit which outputs a comparison result signal Hi indicating this when f exceeds the dead zone QDZ; 11 is a reference value updating circuit which updates the reference value Qst to prevent over-correction of the reactive power Q; When the pulse signal G is output from timer 4, the comparison result signal F is output (vi>'vD).
, )% and if the reactive power Qi is within the dead band, then (Qi
<QDZ), set the reactive power correction value QsN' outputted from the arithmetic circuit 8 at this point in the reference value holding circuit 6,
The reference value Q9' held in the holding circuit 6 is changed to the correction value Q8.
Update to N. Furthermore, at the time when the pulse signal G is output, the comparison result signal F is not output (that is, Vi<
VD2 and Vi is within the dead band), and if the current reactive power input Qi is outside the dead band, the reactive power input Qi at this time is set in the holding circuit 6, and the reference value Qs is updated to Qi. Further, if vi<vDz and the current reactive power Qi is within the dead zone, that is, if the correction amount is appropriate, the correction value QSN? output from the arithmetic circuit 8 at this point? Set as a new reference value Qs.

In the above configuration, the transformer primary side input voltage Vi
has converged within the dead zone, neither the comparison result signal F nor the pulse signal G is generated. Therefore, the arithmetic circuit 8 outputs a correction value θ8N that is equal to the preset reactive power reference value θ5. The on/off operation of the reactive power adjustment relay is controlled according to a preset reactive power reference value θ8. As a result, the input voltage ■i and the reactive power input Qi are set to their respective reference values Vs
and is adjusted within the dead zone centered on QS.

However, if some load fluctuation occurs and the input voltage V1 exceeds the dead band, the comparison result signal F is generated from the comparison circuit 3, the peak hold circuit 5 is reset, and after this seven bits, the input voltage Vi The maximum value ΔV' of the deviation ΔV from the reference value Vs is extracted and sent to the peak hold circuit 5.
Then, the arithmetic circuit 8 executes all the calculations shown in equation (1) based on the maximum value ΔV/r of this deviation Δ■, and corrects the reactive power Qi proportional to the maximum value Δ■'. Value QsN
eCalculate. As a result, the reactive power adjustment relay is turned on and off by this correction value Q8N, and the reactive power Q1 passing through the transformer is corrected in accordance with the correction value Q8N.

When the pulse signal G is generated from the timer circuit 4 while the correction control of the reactive power human power Qi is being fully executed, the reference value update circuit 11 performs a full check to see if the comparison result signal F is generated at this point. , if the signal F is still occurring, it means that the reactive power correction is insufficient, so the reactive power correction value Q8N at this point is set as the new reference value Qs. As a result, the arithmetic circuit 8 calculates a new correction value 08N for the reactive power input based on the new reference value Qs, and adjusts the reactive power input Q1 according to this correction value θSN.

As a result of repeating such adjustments, the input voltage Vi converges within the dead zone, and immediately after this, the pulse signal G is generated.
The reference value updating circuit 11 checks whether the current reactive power input Qi is within the dead zone based on the comparison result signal H, and
If it is within the dead zone, it means that the correction is appropriate, so the reactive power correction value Q8N output from the arithmetic circuit 8 at this point is set as the total reference value QS. ! Ta. Qi
is outside the dead band, the reactive power input Q[
- Set as reference value Qs 7 As a result, the input voltage Vi, which was outside the dead zone due to load fluctuation, is adjusted to within the dead zone.

In this case, when calculating the reactive power correction value QSN in proportion to the deviation ΔV between the input voltage v1 and the reference value Vs, the deviation Δ
Since the maximum value Δ■' of (2) is fully extracted and the correction value QBN' is calculated using this maximum value ΔV', there is no shortage of the correction amount of the reactive power human power Qi necessary for recovering the input voltage Vi. In other words, if the correction value QsN'e is simply calculated in proportion to only the deviation ΔV, the correction amount will be small as the input voltage Vi recovers, and the correction amount will always be insufficient. By using the maximum value ΔV' of the deviation Δ■ from the point at which Vi exceeds the insensitive "band," it is possible to obtain a sufficient correction amount to recover the input voltage Vi. As is clear from the above explanation, The present invention corrects the reactive power reference value in proportion to the maximum value of the deviation between the current value of the primary side input voltage and the reference value when adjusting the transformer primary side input voltage within the dead band, The operation amount of the phase adjustment equipment is fully controlled based on this correction value, and when the primary side input voltage converges within the dead band, the value of the reactive power passing through the transformer at this time is set as the new reactive power reference value, and 1 Next-side input voltage? Adjustment is made according to the reactive power adjustment share of each substation.

Therefore, even if the load and system configuration are significantly different from the expected ones, situations such as the lower power system's functions will not stop will not occur, and reliability can be improved7.
If a proportionality constant is taken into account when calculating all reactive power correction values as in the embodiment.

By simply changing this proportionality constant, it is possible to appropriately allocate the reactive power adjustment share of each substation, which has the effect of facilitating the design of the entire system. This has the effect of minimizing total loss.

[Brief explanation of drawings]

The drawing is a block diagram showing an embodiment of the main part of the present invention. ■...Primary voltage reference value holding circuit, 2...Primary voltage dead band holding circuit, 3...Comparison circuit, 4...Timer, 5
...Peak hold circuit, 6...Reactive power reference value holding circuit, 7...Proportional constant holding circuit, 8...Arithmetic circuit, 9-...Reactive power dead zone holding circuit, 10...Comparison circuit , 11... Reference value update circuit.

Claims (1)

[Claims] In a voltage/reactive power adjustment device that adjusts the primary input voltage of a substation transformer within a dead band centered on a reference value by controlling the operation amount of phase adjustment equipment, the dead band of the primary side input voltage is A comparator circuit that compares the value with the current primary side input voltage value and also calculates the deviation between the reference value of the primary side input voltage and the current primary side input voltage value, and based on the output of this comparison circuit. When the primary side input voltage exceeds the dead band, extract and hold the maximum value of the above deviation, and when the primary side input voltage converges to the dead band, and when the primary side input voltage that completely reduces the dead band continues for a predetermined period of time. A peak hold circuit in which the held value is reset, and a reference value of the reactive power passing through the transformer when the primary side input voltage exceeds the dead zone is corrected in proportion to the maximum value of the deviation held in the peak hold circuit, An arithmetic circuit that controls the operation amount of the phase adjustment equipment based on this correction value, and an arithmetic circuit that controls the operation amount of the phase adjustment equipment based on the output of the above-mentioned comparison circuit. A reactive power reference value update circuit that sets the reference value of reactive power and sets the correction value calculated by the above calculation circuit as the reference value of reactive power passing through the transformer when the primary side input voltage exceeding the dead zone continues for a predetermined time. A voltage/reactive power regulator comprising: