JPH0519873A - Voltage regulation device - Google Patents

Abstract

PURPOSE:To prevent frequent operation and to rationally regulate the voltage of a system including the current suppression of the system by providing a voltage measuring means, a reactive power measuring means, and a tap control means. CONSTITUTION:The electric power system is provided with a voltage measuring means (voltage transformer for instrument) which measures the secondary side voltage of a transformer 3 associating a mountain-side power source 1 and a village-side power source 2, a reactive power measuring means (current transformer) 6 which measures the secondary side reactive power of the transformer 3, and a tap control means (voltage regulation device) 7 which controls the tap switch 4 of the transformer 3 according to the mutual relation between the measured voltage and reactive power. The tap control means 7 controls the tap switch 4 of the transformer 3 according to the operation state of phase adjusting facilities which are arranged further outside. Consequently, the frequent operation is prevented and the voltage of the system can rationally be regulated including not only the mere elimination of voltage deviation, but also the current suppression of the system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a tap changer used for operating while maintaining the voltage of an electric power system owned by an electric power company, an electric power company for private use, or a corporation at an appropriate value. The present invention relates to a voltage adjusting device that adjusts a tap of a transformer.

[0002]

2. Description of the Related Art Conventionally, for the purpose of maintaining and adjusting the voltage of a power transmission and distribution system, a transformer with a tap changer and a voltage adjusting device (relay) for measuring and detecting the voltage of the system and adjusting the tap of the tap changer. By detecting the deviation of the voltage of the system from the reference value by combining with, the appropriate control output is issued according to the deviation, and the tap position of the tap changer is changed. Was the majority. In this method, as shown in FIG. 10, a constant functional relationship is provided between the deviation ΔV (horizontal axis) of the system voltage and the operating time T (vertical axis) of the voltage regulator, and the system responds to an instantaneous change in the system voltage. I was trying not to.

However, even with a voltage regulator having such characteristics, when the voltage fluctuations in the system frequently occur, the number of times of operation of the voltage regulator is increased, and accordingly, the number of times of operation of the tap changer is also increased. . Generally, since the tap changer always includes a movable mechanism part, a large number of times of operation thereof leads to a reduction in the mechanical life of the movable part.

[0004]

In the conventional voltage regulator as described above, as a practical operation, the number of operations per day should be kept below a certain number, and the operation should not be performed more than that number. It's locked. There is a problem that such a countermeasure is not an essential solution contrary to the purpose of installing the device.

The present invention has been made in order to solve the above-mentioned problems, and prevents frequent operations and regulates the voltage of the system not only by simply eliminating the voltage deviation but also by suppressing the cross current in the system. The purpose is to obtain a voltage regulator that can be rationalized.

The details will be described below. FIG. 1 shows a system configuration of two rear power sources 1 and 2, a voltage adjusting device 7 provided at one point in the middle thereof, and a transformer 3 with a tap changer. In this system configuration, the change in the voltage and the reactive power when the back power supply fluctuates moves on a straight line as shown in FIG. In FIG. 2, the horizontal axis represents the voltage deviation ΔV, and the vertical axis represents the reactive power deviation ΔQ. The following is a formal description of this. First, it is generally expressed as follows. ΔV = X ₂ / (X ₁ + X ₂ ) · (Δn + ΔV ₁ ) + X ₁ / (X ₁ + X ₂ ) · ΔV ₂ ... Formula 1 ΔQ = 1 / (X ₁ + X ₂ ) · (Δn + ΔV ₁ −ΔV ₂ ) ... Equation 2 If there is no change in the system, both ΔV ₁ and ΔV ₂ are 0. Therefore, when Δn occurs, there is a relation of ΔV = X ₂ · ΔQ, and ΔV and ΔQ then X ₁ and X ₂
I understand.

Further, if the tap is not operated, when there is a change in the system, using the above equations 1 and 2, ΔV ₁ = ΔV + X ₁ ΔQ Equation 3 ΔV ₂ = ΔV−X ₂ ΔQ From Equation 4, the magnitude of the voltage change of the power supply behind the system is known. That is, the constant of the system can be estimated by changing the voltage and the reactive power by changing the power supply behind the system or operating the tap.

Based on the above knowledge, the operation for adjusting the voltage will be examined. When the back-up power supply fluctuates and changes in voltage and reactive power, only focusing on adjusting the tap of the transformer to eliminate the deviation of the voltage, the reactive power is higher than before as shown by point X in the figure. Will also increase.
As a result, there is a possibility that the loss of the system is rather increased and the situation becomes unfavorable.

Further, even when the phasing equipment is operated and the reactive power changes at a point other than the substation where the transformer with a tap changer is installed, the current values for the desired voltage and reactive power in the conventional method are changed. The relationship between the voltage deviation and the reactive power deviation cannot be detected by the voltage regulator, so only the operation to adjust the voltage is performed, and as a result, the reactive power increases rather than the above, resulting in system loss. Will result in the adverse effect of increasing.

This is specifically shown in the drawings. The operating range of the voltage regulator is the entire region except the dead zones VD1 and VD2 on the ΔV-ΔQ plane of FIG. 2, but the tap changer is operated so as not to exceed the cross current limits QL1 and QL2. The effective range is 1st and 3rd from the origin.
Limited to the range of OP centered on the quadrant. because,
This is because ΔV and ΔQ that change by operating the tap changer move on a straight line that passes through the origin and is parallel to the straight line N having a slope of 1 / X ₂ .

On the contrary, when ΔV and ΔQ are in the second and fourth quadrants, the reactive power increases even if the tap changer is operated so that the voltage falls within the dead zone.
In this case, the external phasing equipment is operated to increase / decrease ΔQ, but ΔQ moves on a straight line that passes through the origin and is parallel to the straight line Q having a slope of −1 / X ₁ .

That is, since the reactive power that changes by the operation of the tap changer and the reactive power that increases and decreases by the operation of the phasing equipment change independently of each other, the voltage regulator is locked even if only the voltage is suppressed within the specified range. It may result in defeating the initial purpose.

The present invention has been made to solve the above-mentioned problems, and as described above, unnecessary operation of the transformer with a tap changer is reduced as much as possible, and the voltage and reactive power of the system are appropriately adjusted. It is intended to be placed in a simple state.

The voltage regulator according to the present invention detects the voltage of the grid and also detects the reactive power flowing through the grid, and determines the magnitude relationship between the two to give an operation command for the transformer with tap changer. , It is designed to be more effective than the one generated by paying attention only to the magnitude of the voltage. In addition, after the operation of the phase-modulating equipment of the system installed outside the substation, Detect the condition,
The operation of the taps and the phase adjusting equipment is optimized.

An example of the characteristics is shown in FIG.
FIG. 2 shows a voltage dead zone sandwiched between straight lines VD1 and VD2 parallel to the vertical axis, an allowable reactive power range sandwiched between two straight lines QL1 and QL2 parallel to the horizontal axis, and four intersection points Q of these four straight lines.
1, Q2, Q3, Q4, two intersections Q12, Q34 between the two straight lines QL1, QL2 and the vertical axis, and a slope 1 /
And the straight line N of X _2, intersections Q12, 2 and a straight line N1, N2 parallel as a straight line N to Q34, intersection Q2, Q4 street linear N
2 straight lines N12 and N24 parallel to
A straight line Q of 1 / X _{1 and} a straight line Q passing through intersection points Q12 and Q34
It is divided into the following four types of regions by two straight lines Q1 and Q2 which are parallel to.

That is, 2 which exists around the first and third quadrants and is surrounded by straight lines N1 and N2 and VD1 and VD2
A region OP (Operate) at one place and two groups of straight lines VD1, QL2 and VD2, QL in the second and fourth quadrants.
Two regions L (Lock) surrounded by 1 and two pairs of parallel straight lines N1, N12 and N2, N which are in contact with both sides of the region OP
There is a band-shaped area T (Try) surrounded by 24 and each quadrant,
Region T and voltage dead band VD1, VD2 or region T and two sets of four regions W sandwiched by region T and permissible reactive power range QL1, QL2
There is (Wait).

First, when (ΔV, ΔQ) is in the first and third quadrants, it is generally better to mainly perform the tap operation.
If it is the area OP, both can be operated and controlled to the desired range. However, when ΔV is small and ΔQ is large, that is, (ΔV,
When ΔQ) is within the area W, it is a case where it is better to wait without operating the tap.

On the other hand, when (ΔV, ΔQ) is in the second and fourth quadrants, it is often better to lock or wait the tap operation mainly. Here, after operating the external phasing equipment, it is necessary to start. Voltage adjustment by tap operation becomes effective.

When (ΔV, ΔQ) is in the area L, it is preferable to lock it because the tap only operates in the area W. Although rare, a straight line N
In the region T surrounded by 1, N12 and the straight lines N2, N24, the taps are finely manipulated to generate QL1, VD2, N1 and QL2, V.
Two small triangular areas ZS surrounded by D1 and N2
The control is successful if it can be driven into (+) and ZS (-). However, since this is a precise operation, a trial T is set.

As described above, by providing the operation command of the transformer with tap changer with the case of waiting or locking, the adjusting operation becomes more accurate and occurs in the system as compared with the case of the conventional voltage adjusting device. The loss due to the cross current can be optimized and the voltage deviation can be kept within a reasonable range.

As described above, the present invention detects the voltage near the transformer with the tap changer and the reactive power of the related system, and depending on the size relationship between the two, adjusts the voltage by operating the tap changer. Is partially locked. Therefore, even if the partial voltage value does not come closest to the target value, the reactive power is maintained at an appropriate value, and the loss in grid operation is optimized.

Further, when the tap is operated after detecting the state after the operation of the phase adjusting equipment, a so-called voltage reactive power control device can be expected to have an effect similar to that of VQC for operating both the tap and the phase adjusting equipment. There is also.

Further, the control of the present invention is based on the principle of determining the optimum manipulated variable while detecting the state change of the system, unlike the conventional VQC in which the operating characteristic is a preset fixed operating characteristic. Therefore, it is necessary to transmit the state quantity of the grid from each point in real time.
Compared to C, simpler and simpler transmission can be expected to have the same or better effect.

[0024]

The voltage regulator according to the present invention comprises the following means. [1] Voltage measuring means for measuring the voltage on the secondary side of the transformer that links the power sources on the mountain side and the village side in the power system. [2] Reactive power measuring means for measuring the reactive power on the secondary side of the transformer. [3] Tap control means for controlling the tap changer of the transformer based on the mutual relationship between the measured voltage and reactive power.

[0025]

In the present invention, the voltage measuring means allows
In the power system, the voltage on the secondary side of the transformer that links the mountain side and the village side power source is measured. In addition, the reactive power measuring means measures the reactive power on the secondary side of the transformer.
Then, the tap control means controls the tap changer of the transformer based on the mutual relationship between the measured voltage and the reactive power.

[0026]

【Example】

Example 1. The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the first embodiment of the present invention.

In FIG. 3, 1 is a mountain side power source, 2 is a village side power source, 3 is a transformer that links both power sources 1 and 2, 4 is a tap changer attached to the transformer 3, and 5 is a transformer. An instrument voltage transformer for measuring the voltage on the secondary side of 3, a current transformer 6 for measuring the reactive power flowing between the power sources 1 and 2, and a voltage regulator 7.

Next, each part of the voltage regulator 7 will be described. Reference numeral 71 is a voltage converter VC for converting the secondary voltage of the voltage transformer 5 to DC, and 72 is a reactive power converter QC for receiving the secondary side output of the transformers 5, 6 and converting reactive power by both to DC. Reference numeral 73 denotes a tap position display converter TC which receives information indicating the position of the tap changer 4 and generates a corresponding bit pattern.

Both 74a and 74b are sample and hold amplifiers, the former holding and storing the output of the voltage converter 71 and the latter holding and storing the output of the reactive power converter 72, respectively. Reference numeral 75 is a level converter for converting the output of the tap position display converter 73 into a level suitable for reading. A multiplexer M 76 receives the analog voltage output from the sample hold amplifiers 74b and 74b and switches the analog voltage output.
It is PX. Reference numeral 77 is an A / D converter ADC, which outputs the analog voltage switched and applied by the multiplexer 76 as a binary bit pattern corresponding to the value. Reference numeral 78 denotes a microcontroller MCU that controls the function of the voltage adjusting device 7, and includes an input / output port, a memory, and a CPU. In addition, the performance and scale are commercially available at the present time, and those which are commercially available and which can be sufficiently put into practical use can be realized. Reference numeral 79 is an interface IF. A printer connected to the microcontroller 78 is also provided inside the voltage adjusting device 7.

Reference numeral 8 denotes a controller LTCC attached to the main body of the tap changer 4, which has almost the same contents as those contained in the normal control panel of the tap changer 4 and is used for raising the tap output from the input / output port of the microcontroller 78. , Receives the command output of lowering, and executes various sequences for moving the tap of the main body. Reference numeral 9 is an external phase adjusting device, which is connected to the voltage adjusting device 7 by a signal line.

By the way, the voltage measuring means of the present invention comprises the voltage transformer 5 for an instrument, the voltage converter 71 and the sample hold amplifier 74a in the first embodiment of the present invention described above. In the first embodiment, the voltage transformer 5, the current transformer 6, the reactive power converter 72, and the sample hold amplifier 74b are included in the tap control means of the first embodiment. It comprises a device 73, a level converter 75, a microcontroller 78 and an IF 79.

Next, the operation of the above-described first embodiment will be described with reference to FIGS. 4 to 9. 4 to 9 are flowcharts showing the operation of the first embodiment of the present invention.
The flowcharts shown in FIGS. 4 to 9 are roughly divided into three parts. The first part is a part for estimating the back reactance of the system from the state quantity of the system measured in real time. Also,
The second part is the part that measures the system state quantity in real time and calculates and grasps the various amounts necessary for control operation, and what kind of operation is performed from the interrelationship of the calculated system state quantity. This is the part that makes the determination. Finally, the third part is a part for performing a general treatment of the device after issuing the operation command.

Flow charts of the operation corresponding to the first part are shown in FIGS. In step 11, when the apparatus is started, a normal control apparatus initialization operation (table clear) is first performed.

In steps 12 to 15, the system voltage V and the reactive power Q flowing in the power system are measured and read.
At the same time, the timer is started and the time is measured for a certain time, and then the measurement is performed again. If this measurement reading is appropriate, proceed to the following, otherwise return to the above measurement procedure.

In Steps 16 to 17, if the results of these measurements show large changes ΔV and ΔQ in the voltage V and reactive power Q, the results are used to determine the rear reactances X ₁ and X ₂ on the mountain side and the village side of the system. Estimate as a trial.

The method uses reactances X ₁ and X ₂ calculated by equations (5) and (6) by using values prepared in advance as predetermined allowable values of variation widths ΔV ₁ and ΔV ₂ of the power supply voltage behind the system.
Check if the value deviates greatly from the value calculated in advance offline.

X ₁ = (1 / ΔQ) · (ΔV ₁ −ΔV) Equation 5 X ₂ = (1 / ΔQ) · (ΔV−ΔV ₂ ) Equation 6

In steps 18 to 19, if the above result is valid, the process proceeds to full-scale estimation which will be described later, but if not, tap operation for the next estimation is performed. In steps 20 to 22, in order to measure the change in the system state due to the tap operation, the measurement is performed again immediately after the operation command and after a lapse of a fixed time.

In step 23, if the result of this reading is appropriate, the process proceeds to the next estimation, and if not, the process returns to the reading procedure again. In steps 24 to 25, as a result of reading, the voltage V, the change ΔV in the reactive power Q,
If ΔQ is large, the calculation required for estimation can be performed, and therefore, the rear reactances X ₁ and X ₂ on the mountain side and the village side of the system are estimated in the same manner as in steps 16 to 17.

In step 26, this estimation result is compared with the results of steps 16 to 17, or compared with a previously given off-line system constant, and if it is a proper value, the estimated system reactance X ₁ , Used as X ₂ data. In steps 27 to 30, in order to fully estimate the system reactances X ₁ and X ₂ , tap Δn operation is performed and the system change due to the influence is measured. The method is the same as steps 20 to 22 above.

In steps 31 to 32, if the changes in ΔV and ΔQ are large in the estimation measurement of the system constants, the system reactances X ₁ and X ₂ are fully estimated using this result. If it is smaller, the operation returns to the tap Δn operation again. As a result of the full-scale estimation of the system reactances X ₁ and X ₂ in step 33, if the values are proper values, the estimation is completed, and the next second
Move to department. If it is inappropriate, the operation of tapping is performed again.

Flow charts of a portion corresponding to the second portion are shown in FIGS. 7 and 8. The first part of the second part is a part for calculating and grasping various amounts necessary for performing the control operation.

In steps 34 to 36, after the rear reactances X ₁ and X _{2 of the system} have been established, the voltage V and the reactive power Q are set as the next step in order to shift to the control for eliminating the deviation.
Read. After reading once, after a certain period of time, the second reading is performed. If the values of ΔV and ΔQ are appropriate from this value, the next calculation is performed, but if not, the process returns to reading again.

In step 37, the operation for determining which range of the control region ΔV and ΔQ belongs to is to determine which of the following inequalities is satisfied to obtain a logical output.

(1) Area L ΔQ−ΔQ _{L +} ≧ 0 Equation 7 and ΔV−ΔV _D− ≦ 0 Equation 8

[0046] or an area of the second and fourth quadrants of the corner defined by a combination of two _{ΔQ-ΔQ L-} ≦ 0 ... Equation 9 and ΔV-ΔV _{D +} ≧ 0 ... Equation 10.

(2) Region W ΔQ−ΔQ _{L +} ≧ (1 / X ₂ ) · (ΔV−ΔV _D− ) ... Equation 11 and ΔV ≧ ΔV _{D +} Equation 12

ΔQ−ΔQ _L− ≦ (1 / X ₂ ) · (ΔV−ΔV _{D +} ) Equation 13 and ΔV ≦ ΔV _D− Equation 14

ΔV ≦ ΔV _D− Formula 15 and ΔQ ≦ ΔQ _{L +} Formula 16 and (ΔQ−ΔQ _{L +} ) − (1 / X ₂ ) · (ΔV−ΔV _D− ) ≧ 0 Formula 17

ΔV ≧ ΔV _{D +} Formula 18 and ΔQ ≧ ΔQ _L− Formula 19 and (ΔQ−ΔQ _L− ) − (1 / X ₂ ) · (ΔV−ΔV _{D +} ) ≧ 0 Formula 20

The straight line N12 on the upper side of the first quadrant and the dead zone right side V
D1, two triangular portions formed by the straight line N24 on the lower side of the third quadrant and the dead zone left side VD2, the negative side of the reactive power allowable range QL1 and the straight line N12, and the triangular portion surrounded by the negative side of the reactive power allowable range QL2 and the straight line N24. Two total four are shown.

(3) For the region T ΔV ≧ ΔV _{D +} or ΔV ≦ ΔV _D− Equation 21 (ΔQ−ΔQ _{L +} ) − (1 / X ₂ ) · (ΔV−ΔV _D− ) ≦ 0 Equation 22 And (ΔQ−ΔQ _{L +} ) − (1 / X ₂ ) · ΔV ≧ 0 Equation 23

And (ΔQ-ΔQ _L -)-(1 / X ₂ ) · (ΔV-ΔV _{D +} ) ≧ 0 Equation 24 and (ΔQ-ΔQ _L -)-(1 / X ₂ ) _× ΔV ≦ 0 Positive / negative voltage dead zone VD determined by the combination of two kinds of equation 25
1 and VD2 and two parallel lines N1 and N12 surround the two bands, and four bands are also surrounded by the positive and negative voltage dead zones VD1 and VD2 and the parallel two straight lines N2 and N24.

(4) Region OP For ΔV ≧ ΔV _{D +} or ΔV ≦ ΔV _D− Equation 26 {(ΔQ−ΔQ _{L +} ) − (1 / X ₂ ) · ΔV} ≦ 0 Equation 27 and {(ΔQ _{-ΔQ L-) - (1 / X} 2) · ΔV} is determined by a combination of ≧ 0 ... equation 28 shows two portion surrounded by two parallel straight lines N1, N2 and the positive and negative voltage dead zone VD1, VD2.

The second part of the second part is a part for calculating the control amount necessary to eliminate the voltage deviation ΔV and the reactive power deviation ΔQ (step 38). Since there is no control in the regions L and W, no calculation is necessary.
Will be described.

(1) Region T The region T has a merit only when it is possible to find Δn satisfying 0 <ΔQ ≦ ΔQ _{L +} equation 29 and ΔV _D− ≦ ΔV ≦ 0 equation 30.

Assuming that the system voltage is not disturbed before and after the control, 0 <Δn / (X ₁ + X ₂ ) ≦ ΔQ _{L +} Equation 31 ΔV _D− ≦ (X ₂ · Δn) / (X ₁ + X ₂ ) ≦ 0 ... Solves Equation 32 to find a satisfying Δn. However, there is a possibility that no solution exists because the region where this value exists is narrow.

(2) Area OP (X ₂ · Δn) / (X ₁ + X ₂ ) ≧ ΔV _{D +} or ≦ ΔV _D- Formula 33 and ΔQ _L- ≦ Δn / (X ₁ + X ₂ ) ≦ ΔQ _{L +} Formula 34 is solved to find a satisfying Δn.

The third part of the second part is the current voltage deviation Δ.
V is a part for performing determination and output operation of what kind of operation is to be performed from the mutual relation determination conditional expression of the system state quantity in which V and reactive power deviation ΔQ are calculated as described above.

In steps 40 to 41, first, Δ
Whether or not V and ΔQ belong to the region L is determined by Expressions 7 to 10. At this time, if the above equations are satisfied, the device outputs the lock output L.

In steps 42 to 43, next, when the above relationship is not established, it is determined from equations 11 to 20 whether ΔV and ΔQ belong to the region W. At this time, if the above equations are satisfied, the device outputs the standby output W. If the phasing equipment operates in the external system and the reactive power changes, it changes from the second quadrant to the fourth quadrant or vice versa toward the region OP or rarely the region T. Look at the situation and wait for the next action.

In steps 44 to 45, if the above relationship is not established, it is determined from equations 21 to 25 whether ΔV and ΔQ belong to the region T.
At this time, if the above equations are satisfied, the device outputs a trial output T.

Since the control performed by the trial output T in step 45a is a control in a narrow range, it may not be successful depending on the accuracy of the measurement / detection portion.
In particular, if the external phasing equipment operates and the reactive power changes,
It is easy to move to the area OP. In this case, it is only necessary to perform a tap operation once within the upper and lower limits of the reactive power allowable range to move ΔV and ΔQ, notify the required reactive power operation amount to the outside, and then perform the external operation. , Transmit and output the amount of reactive power operation required externally.

Finally, in steps 46 to 47, Δ
When V and ΔQ do not satisfy the above equations 7 to 25, it is determined whether or not the above equations 26, 27, and 28 are satisfied, and if they are satisfied, the tap operation is performed. Output OP.

In step 47a, even if ΔQ is driven to a point within the upper and lower limits of the reactive power allowable range by the operation output OP, which of the voltage deviation and the reactive power deviation is reduced depends on the system operation. At this time, it is appropriate to perform the tap operation in coordination with the operation of the external phase adjusting equipment, so the forecast before and after the operation is output to the outside, and the reactive power of the phase adjusting equipment that you want to operate externally is output. Transmit and output.

In the third part, the treatment of the entire device after issuing the operation command is performed. Flow charts of a portion corresponding to the third part are shown in FIGS. 8 and 9.

In steps 48 to 51, the judgment operation command of the second part is output to the outside of the apparatus, and after a lapse of a predetermined time, V and Q are read for confirmation, and if appropriate in view of the contents of the operation, Proceed to the next confirmation estimation, and if it is not appropriate, it is regarded as a read abnormal operation and output.

In steps 52 to 55, the system reactances X ₁ and X ₂ are estimated using the measured values, and if these values are appropriate, these values are used as new system reactances X ₁ and X _2.
Is set as a constant inside the device. If it is not appropriate, it is recorded as an estimated abnormality.

In steps 56 to 59, finally, the voltage and the reactive power are read, and if appropriate, the operation is recorded as a normal operation completion, and if not, the system change is recorded because there is a system change during the operation. While performing, the process returns to the start of the series of processes described above.

The first embodiment of the present invention, as described above,
Not only the system voltage but also reactive power flowing back into the system is measured to estimate the reactance behind the system, and while determining the mutual relationship between voltage and reactive power, operation, trial, standby, locking Since the (lock) output is output, it is possible to avoid the unnecessary operation of the tap changer as in the related art, and it is possible to prevent the reactive power from increasing due to the overshooting operation of the tap switch.

Further, by issuing a request regarding the operation of the external phase adjusting equipment from the operating condition of this device and linking it with the operation of the tap changer, a more preferable cooperative operation can be expected as a system device.

[0072]

As described above, according to the present invention, the voltage measuring means for measuring the voltage on the secondary side of the transformer, which links the power sources on the mountain side and the village side in the power system, and the secondary side of the transformer. Since the reactive power measuring means for measuring the reactive power and the tap control means for controlling the tap changer of the transformer on the basis of the mutual relation between the measured voltage and the reactive power are provided, frequent operations are prevented. In addition, the voltage of the system can be adjusted not only by simply eliminating the voltage deviation but also by rationally suppressing the cross current of the system.

[Brief description of drawings]

FIG. 1 is a diagram showing a power system as a target of a first embodiment of the present invention.

FIG. 2 is a diagram showing the operation of Embodiment 1 of the present invention.

FIG. 3 is a block diagram showing a first embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 10 is a diagram showing characteristics of a conventional voltage regulator.

[Explanation of symbols]

1 Mountain side power supply 2 ri side power supply 3 transformer 4-tap switch 5 Meter voltage transformer 6 Current transformer 7 Voltage regulator 78 Micro controller

Claims (3)

[Claims] 1. A voltage measuring means for measuring a voltage on a secondary side of a transformer which links a mountain side and a village side power source in a power system,
A reactive power measuring means for measuring reactive power on the secondary side of the transformer; and a tap control means for controlling a tap changer of the transformer based on a mutual relationship between the measured voltage and reactive power. A voltage regulator characterized by. 2. The voltage regulator according to claim 1, wherein the tap control means controls the tap changer of the transformer on the basis of the operating state of the externally arranged phase adjusting equipment. 3. A transmission means is provided for transmitting to the phase-adjusting equipment the operating conditions of the phase-adjusting equipment obtained on the basis of the mutual relationship between the measured voltage and reactive power and the operating state of the phase-adjusting equipment. The voltage regulator according to claim 2, which is characterized in that.