JP6755812B2 - Phase voltage calculator and automatic voltage regulator - Google Patents

Description

The present invention relates to a phase voltage calculation device for calculating the phase voltage on the primary side and the secondary side of a transformer, and an automatic voltage regulator including the phase voltage calculation device.

Conventionally, in a distribution system, an automatic voltage regulator (SVR) for distribution has been installed in order to keep the voltage of the system within a set range. The automatic voltage regulator automatically adjusts the voltage by switching the energizing tap of the adjusting transformer according to the voltage on the secondary side, for example.

In the distribution system, a plurality of systems are linked from the viewpoint of balancing the supply and demand of electric power and preventing power outages. Therefore, when the system is switched, reverse power transmission may occur in the automatic voltage regulator.

Further, in recent years, private power generation facilities such as solar power generation facilities and wind power generation facilities have been installed, and such private power generation facilities have come to cooperate with the distribution system as distributed power sources. Therefore, when the amount of power generated by the distributed power source increases, reverse power flow may occur in the automatic voltage regulator despite the forward power transmission, and conversely, the automatic voltage adjustment despite the reverse power transmission. Since the flow may be smooth in the device, the power transmission direction (substation direction) and the power flow direction in the automatic voltage regulator do not always match.

Therefore, it is known that if the automatic voltage adjustment is performed only by the information of the tidal current direction in the automatic voltage regulator without grasping the power transmission direction (substation direction), the voltage adjustment will be inappropriate. For example, in a complete reverse feed type SVR (bidirectional voltage adjustment type SVR) that adjusts the secondary side voltage during forward feed and adjusts the primary side voltage during reverse feed, reverse power flow due to the distributed power supply occurred during forward feed. When the mode is switched to the mode for adjusting the primary side voltage accordingly, the primary side voltage does not change and the secondary side voltage changes in the direction of decreasing when the primary side voltage is adjusted to increase. This will result in improper voltage adjustment.

Therefore, the power transmission direction is determined by comparing the amount of change in the primary side voltage at the time of tap switching of the adjustment transformer in the automatic voltage regulator with the amount of change in the secondary side voltage (for example). , Patent Document 1). In that determination, it is necessary to know the amount of change in the primary voltage. As the amount of change in the primary side voltage, the result measured by using a voltage transformer (VT) on the primary side of the adjusting transformer is usually used.
For a purpose different from the determination of the power transmission direction, a method of calculating the primary side voltage by using the secondary side voltage and the difference between the primary side voltage and the secondary side voltage is known (Patent Document 2). reference).

Japanese Unexamined Patent Publication No. 2000-295774 Japanese Unexamined Patent Publication No. 10-117438

Here, in the automatic voltage regulator, the line voltage is used for voltage adjustment. On the other hand, in Patent Document 2, the secondary side phase voltage is measured, the difference between the primary side phase voltage and the secondary side phase voltage is also measured, and the primary side phase voltage is calculated by using both measurement results. ing. Therefore, in SVR, when calculating the primary side phase voltage using the technique described in Patent Document 2, the secondary side line voltage is measured for voltage adjustment and the transmission direction is determined. There is a problem that it is necessary to measure the secondary side phase voltage as well, and many voltage transformers are required.

The present invention has been made to solve the above problems, and provides an apparatus and the like capable of acquiring a primary side phase voltage and a secondary side phase voltage without using many voltage transformers. The purpose is.

In order to achieve the above object, the phase voltage calculation device according to the present invention is a phase voltage calculation device that calculates the primary side phase voltage and the secondary side phase voltage of an adjustment transformer having a plurality of taps, and is an adjustment transformer. A line voltage measuring unit that measures a plurality of secondary side line voltages, a secondary side phase voltage calculating unit that calculates a secondary side phase voltage using a plurality of secondary side line voltages, and a primary side phase voltage. The primary side phase is used by the difference voltage measuring unit that measures the difference voltage, which is the difference between the voltage and the secondary side phase voltage, the secondary side phase voltage calculated by the secondary side phase voltage calculation unit, and the difference voltage. It is provided with a primary side phase voltage calculation unit for calculating a voltage.
With such a configuration, the secondary side phase voltage can be calculated using the secondary side line voltage, so that it is not necessary to use a voltage transformer for measuring the secondary side phase voltage. Therefore, it becomes possible to obtain the primary side phase voltage and the secondary side phase voltage with a smaller number of voltage transformers.

Further, in the phase voltage calculation device according to the present invention, the secondary side phase voltage calculation unit may calculate the secondary side phase voltage by the following equation.
V _2V = 2/3 x (V _2VW + 1/2 x V _2WU )
(In the equation, V _2V is the secondary side line voltage of the second phase, V _2VW is the secondary side line voltage between the second phase and the third phase, and V _2WU is the third phase. The voltage between the secondary siding and the first phase.)
With such a configuration, the secondary side phase voltage can be calculated from the secondary side line voltage by using the above equation.

Further, in the phase voltage calculation device according to the present invention, the line voltage measuring unit measures the three secondary side line voltages, and the secondary side phase voltage calculating unit calculates the secondary side phase voltages of a plurality of phases. The difference voltage measuring unit may measure the difference voltage of a plurality of phases, and the primary side phase voltage calculating unit may calculate the primary side phase voltage of the plurality of phases.
With such a configuration, the primary side phase voltage of a plurality of phases can be calculated. Then, for example, by determining the power transmission direction using the primary side phase voltages of the plurality of phases calculated in this way, it becomes possible to perform a more accurate determination.

Further, the automatic voltage regulator according to the present invention includes a phase voltage calculation device, an adjusting transformer, a tap changer for switching the energizing tap of the adjusting transformer, and a primary side phase when the energizing tap is switched by the tap changer. Judgment unit and judgment unit that determine the transmission direction using the amount of change in the primary side phase voltage calculated by the voltage calculation unit and the amount of change in the secondary side phase voltage calculated by the secondary side phase voltage calculation unit. It is provided with a tap changer controller that controls the tap changer according to the transmission direction and the voltage of the adjusting transformer determined by.
With such a configuration, it is possible to determine the power transmission direction in the automatic voltage regulator by using the primary side phase voltage and the secondary side phase voltage calculated by the phase voltage calculation device. Normally, in an automatic voltage regulator, the line voltage is measured because the voltage is adjusted using the line voltage. Therefore, by calculating the primary side phase voltage and the secondary side phase voltage using the secondary side line voltage measured in this way, it is not necessary to separately provide an instrument transformer for measuring the phase voltage. , It becomes possible to judge the transmission direction.

According to the phase voltage calculation device or the like according to the present invention, the primary side phase voltage and the secondary side phase voltage can be obtained by using a small number of voltage transformers.

A block diagram showing a configuration of an automatic voltage regulator according to an embodiment of the present invention. A flowchart showing the operation of the phase voltage calculation device in the same embodiment. The figure which shows the adjustment transformer in the same embodiment. The figure which shows an example of the structure of the tap changer in the same embodiment Explanatory drawing about voltage measurement and voltage calculation in the same embodiment Vector diagram showing the primary side voltage and the secondary side voltage in the same embodiment

Hereinafter, the phase voltage calculation device according to the present invention and the automatic voltage regulator provided with the phase voltage calculation device will be described with reference to embodiments. In the following embodiments, the components with the same reference numerals are the same or correspond to each other, and the description thereof may be omitted again. In the automatic voltage regulator according to the present embodiment, the secondary side phase voltage of the adjusting transformer is calculated by using the secondary side line voltage, and the primary side phase voltage is calculated by the calculated secondary side phase voltage and the primary side phase voltage. It is equipped with a phase voltage calculation device that calculates using the difference between the side phase voltage and the secondary side phase voltage.

FIG. 1 is a block diagram showing a configuration of an automatic voltage regulator 1 according to the present embodiment. The automatic voltage regulator 1 according to the present embodiment includes an adjusting transformer 11, a tap switching device 12, a tap switching controller 13, a determination unit 14, and a phase voltage calculating device 2. The phase voltage calculation device 2 calculates the primary side phase voltage and the secondary side phase voltage of the adjusting transformer 11, and is the line voltage measuring unit 21, the secondary side phase voltage calculating unit 22, and the difference voltage. A measurement unit 23 and a primary side phase voltage calculation unit 24 are provided. The automatic voltage regulator 1 may be, for example, a tap fixed type SVR at the time of reverse feed, which adjusts the secondary side voltage at the time of forward feed and fixes the energizing tap at the time of reverse feed, and the secondary side voltage at the time of forward feed. It may be a complete reverse feed type SVR (SVR of the bidirectional voltage adjustment method) that adjusts the voltage of the primary side at the time of reverse feed, or it may be an SVR by another method.

The adjusting transformer 11 has a plurality of taps, the primary side is connected to the primary side distribution line 4, and the secondary side is connected to the secondary side distribution line 5. The distribution lines 4 and 5 are U, V, and W three-phase distribution lines. Further, the adjusting transformer 11 usually has a plurality of taps on the primary side. Of the plurality of taps, the tap used for energization will be referred to as an energizing tap. As shown in FIG. 3, the adjusting transformer 11 may be a star-connected transformer of each phase. In this embodiment, the case will be mainly described. The transformer of each phase may be, for example, an autotransformer.

The tap switching device 12 switches the energizing tap of the adjusting transformer 11 in response to the tap switching command output from the tap switching controller 13. FIG. 4 is a diagram showing an example of the configuration of the autotransformer 11a in a certain phase and the tap switch 12a for switching the energizing tap of the autotransformer 11a. The secondary side of the autotransformer 11a is connected to the tap tp5, and the primary side is connected to any of the taps tp1 to tp9 by the tap switch 12a. The tap connected by the tap switch 12a becomes an energizing tap. The autotransformer 11a transforms the primary side voltage V1 to the secondary side voltage V2. In FIG. 4, since the switch of the tap tp2 is turned on, the tap tp9 to the tap tp5 form a shunt winding, and the tap tp5 to the tap tp2 form a series winding, which is two with respect to the primary side. The next side will be stepped down. The voltage on the output side can be adjusted by switching the position of the tap to be turned on, that is, the energizing tap. The resistor existing below the tap tp2 is a current limiting resistor used when switching the tap. The tap switch 12 switches the energizing tap for each phase, and switches the energizing tap so that the three phases work together.

The tap switching controller 13 controls the tap switching controller 12 according to the measurement result of the voltage of the adjusting transformer 11. The tap switching controller 13 controls the tap switching controller 12 so as to keep the secondary side line voltage of the adjusting transformer 11 at the target voltage at the time of progressive feeding. Therefore, the tap switching controller 13 may output a tap switching command to the tap switching device 12 by using the secondary side line voltage of the adjusting transformer 11. As the secondary side line voltage, the tap switching controller 13 may use the output voltage of the voltage transformer of the instrument included in the line voltage measuring unit 21. Further, the tap switching controller 13 flows through, for example, a voltage adjusting relay (90 relay) connected in series between the output terminals of a voltage transformer for measuring a secondary side line voltage and a secondary side distribution wire 5. It may be provided with a line voltage drop compensator (LDC) to which the output of the current transformer that detects the load current is input. When the automatic voltage regulator 1 is a tap-fixed type SVR at the time of reverse feed, the tap switching controller 13 may fix the energizing tap at the time of reverse feed. Further, when the automatic voltage regulator 1 is a complete reverse feed type SVR, the tap switching controller 13 sets the tap switch 12 so as to keep the primary side voltage of the adjusting transformer 11 at the target voltage at the time of reverse feed. You may control it. The primary side voltage may be the line voltage measured on the primary side of the regulating transformer 11. Therefore, in the case of a complete reverse feed type SVR, the automatic voltage regulator 1 may include an instrument transformer used for measuring the primary lateral line voltage. When adjusting the voltage on the primary side, the tap switching controller 13 makes the primary side voltage corrected by using the voltage drop in the primary side distribution line 4 predicted by using the primary side current as the target voltage. You may control it. The primary side current used for predicting the voltage drop on the primary side may be measured by using a current transformer on the primary side of the adjusting transformer 11. As described above, in the case of the complete reverse feed type SVR, the automatic voltage regulator 1 may have the same configuration as that used for the voltage adjustment on the secondary side on the primary side. .. The tap switching controller 13 may determine whether the power transmission direction is forward or reverse by using the determination result of the determination unit 14. That is, the tap switching controller 13 may perform tap switching control according to the power transmission direction, which is the determination result, and the voltage of the adjusting transformer 11. Further, the tap switching controller 13 may perform switching control of the energizing tap using one line voltage, or may perform switching control of the energizing tap using a plurality of line voltages. In the latter case, the tap switching controller 13 may perform control so that the representative values of the plurality of line voltages are maintained at the target voltage, for example. The representative value may be, for example, an average value, a median value, or the like. Further, the plurality of line voltages may be two line voltages or three line voltages.

The determination unit 14 makes a determination regarding the power transmission direction (substation direction). That is, the determination unit 14 determines whether the substation is on the primary side or the secondary side. If it is determined that the substation is on the primary side, the transmission direction is forward transmission, and if it is determined that the substation is on the secondary side, the transmission direction is reverse transmission. The determination unit 14 determines the power transmission direction using the amount of change in the primary side phase voltage and the amount of change in the secondary side phase voltage when the energization tap is switched by the tap switcher 12. The determination unit 14 uses the primary side phase voltage calculated by the primary side phase voltage calculation unit 24 and the secondary side phase voltage calculated by the secondary side phase voltage calculation unit 22 to change the primary side phase voltage. The amount and the amount of change in the secondary side phase voltage can be obtained. Determining the power transmission direction using the amount of change in the primary side phase voltage and the amount of change in the secondary side phase voltage means comparing the magnitude of the amount of change in the primary side phase voltage with the amount of change in the secondary side phase voltage. It may be to determine the transmission direction (substation direction). This is because the voltage fluctuation corresponding to the tap switching is usually small on the power supply side where the substation is present and large on the load side where the substation is not present. A method of improving the determination method is described in, for example, Patent Document 1 and the like. A method for determining the power transmission direction using the magnitude of the change in the primary side phase voltage and the change in the secondary side phase voltage at the time of tap switching is already known, and detailed description thereof will be omitted.

The line voltage measuring unit 21 measures a plurality of secondary side line voltages of the adjusting transformer 11. Measuring a plurality of secondary side line voltages means that the line voltage measuring unit 21 measures the secondary side line voltages corresponding to a plurality of different pairs of the three phases. The line voltage measuring unit 21 may measure the two secondary side line voltages or the three secondary side line voltages. In the present embodiment, the former case will be mainly described. In particular, as shown in FIG. 5, the line voltage measuring unit 21 determines the line voltage between the V phase and the W phase on the secondary side and the line between the W phase and the U phase on the secondary side. The case where the inter-voltage is measured using the voltage transformer will be mainly described. The line voltage measured by the line voltage measuring unit 21 is a value that fluctuates with time. The secondary side line voltage measured by the line voltage measuring unit 21 may be used for adjusting the voltage on the secondary side in the tap switching controller 13. In that case, the effective value calculated by using the secondary side line voltage which is an instantaneous value may be used for the voltage adjustment.

The secondary side phase voltage calculation unit 22 calculates the secondary side phase voltage using a plurality of secondary side line voltages measured by the line voltage measurement unit 21. The secondary side phase voltage calculation unit 22 may calculate the secondary side phase voltage of one phase, or may calculate the secondary side phase voltage of a plurality of phases. Here, the case where the secondary side phase voltage of one phase is calculated will be mainly described, and the case where the secondary side phase voltage of a plurality of phases is calculated will be described later. It is preferable that the phase of the secondary side phase voltage is the same as the phase of the difference voltage measured by the difference voltage measuring unit 23. A method of calculating the secondary side phase voltage from the secondary side line voltage will be described with reference to the vector diagram of FIG. In the vector diagram of FIG. 6, the three phases on the primary side are 1U, 1V, 1W, and the three phases on the secondary side are 2U, 2V, 2W. The U, V, and W phases may be referred to as the first phase, the second phase, and the third phase, respectively. Further, in FIG. 6, the measured voltage is shown by a solid line, and the calculated voltage is shown by a broken line. Assuming that the line voltage vector of the three-phase AC of the distribution system is a closed triangle with the virtual neutral point (N in the figure) as the center of gravity, the vector V _2V corresponding to the phase voltage of the 2V phase is as follows. It becomes like an expression.

Moreover, since the instantaneous value of the voltage corresponds to the real number axis of the phasor, the phase voltage can be obtained only by adding or subtracting the instantaneous value of the line voltage, and since vector calculation is not required, the time-varying 2V The phase voltage of the phase can be calculated by the following equation.
V _2V = 2/3 x (V _2VW + 1/2 x V _2WU )

Here, V _2VW is the secondary lateral line voltage between the second phase and the third phase, and V _2WU is the secondary lateral line voltage between the third phase and the first phase. That is, V _2VW is the secondary side line voltage which is the voltage of the 2V phase based on the 2W phase, and V _2WU is the secondary side line voltage which is the voltage of the 2W phase based on the 2U phase. The right side of the above equation can be transformed into various equations, assuming that the line voltage vector is a closed triangle with the virtual neutral point (N in the figure) as the center of gravity. .. The right side of the above equation is expressed using, for example, the secondary side line voltage V _2UV between the first phase and the second phase, and the secondary side line voltage V _{2 VW} between the second phase and the third phase. also, also expressed using secondary side inter-line voltage V _2Wu between the secondary side inter-line voltage V _{2 UV,} and the third phase and the first phase between the first phase and the second phase to You can also do it. Therefore, it may be considered that an equation equivalent to the right-hand side of such an above equation is also included in the above equation. Further, the secondary side line voltage included in the right side of the above equation may be measured by the line voltage measuring unit 21, or is calculated from the measured line voltage. May be good.

When the secondary side line voltages V _2VW and V _2WU are measured by the line voltage measuring unit 21, the secondary side phase voltage calculating unit 22 uses the secondary side line voltages to measure the secondary side. The phase voltage V _2V can be calculated. Since the secondary side line voltages V _2VW and V _2WU measured by the line voltage measuring unit 21 have time-varying values, the secondary side-phase voltage V _2V also has time-varying values.

The differential voltage measuring unit 23 measures the differential voltage, which is the difference between the primary side phase voltage and the secondary side phase voltage of the adjusting transformer 11. The primary side phase voltage and the secondary side phase voltage are phase voltages of the same phase. In the present embodiment, as shown in FIG. 5, the differential voltage measuring unit 23 uses a voltage transformer to measure the difference voltage between the 1V phase phase voltage on the primary side and the 2V phase phase voltage on the secondary side. The case of measuring using is mainly described. The difference voltage measuring unit 23 calculates, for example, a voltage corresponding to the vector V _{1V 2V} shown in FIG. This difference voltage is also a value that fluctuates with time.

The primary side phase voltage calculation unit 24 calculates the primary side phase voltage using the secondary side phase voltage calculated by the secondary side phase voltage calculation unit 22 and the difference voltage measured by the difference voltage measurement unit 23. To do. The relationship between the vector V _1V of the primary phase voltage of 1V phase, the vector V _2V of secondary-phase voltage of 2V phase, the vector V _1V2V differential voltage of V-phase is expressed by the following equation ..

Therefore, the primary side phase voltage calculation unit 24 can calculate the time-varying 1V phase phase voltage by the following equation.
V _1V = V _2V + V _1V2V
The first term V _2V on the right side of the above equation is the secondary side phase voltage calculated by the secondary side phase voltage calculation unit 22, and V _{1V 2V} is the difference voltage measured by the difference voltage measurement unit 23. Therefore, the primary side phase voltage calculation unit 24 can calculate the primary side phase voltage by adding the calculated secondary side phase voltage and the measured difference voltage. Further, the primary side phase voltage calculation unit 24 may calculate the primary side phase voltage as described above, or may calculate the 1U phase primary side phase voltage V _{1U, or} may calculate the 1W phase primary side phase voltage V. _{1 W} may be calculated, or the primary side phase voltage of any two or more combinations thereof may be calculated.

The determination unit 14 uses, for example, the secondary side phase voltage V _2V calculated by the secondary side phase voltage calculation unit 22 and the primary side phase voltage V _1V calculated by the primary side phase voltage calculation unit 24. The power transmission direction can be determined by determining which side, the primary side or the secondary side, the amount of change in voltage at the time of tap switching is large. For example, when the phase voltage of one phase is calculated by the secondary side phase voltage calculation unit 22 and the primary side phase voltage calculation unit 24, the determination unit 14 determines using the phase voltage of that phase. May be done. The determination method is already known. Further, since the secondary side phase voltage V _2V and the primary side phase voltage V _1V are values that fluctuate with time, the determination unit 14 may make a determination using a predetermined instantaneous value or the like. The determination unit 14 may make a determination using, for example, the peak value of the phase voltage, and makes a determination using a value other than the peak value (for example, a peak-to-peak value). May be good.

The phase voltage calculation device 2 may calculate the secondary side phase voltage and the primary side phase voltage only at the time of determination by the determination unit 14, that is, at the time of tap switching, or at the time of tap switching. The secondary side phase voltage and the primary side phase voltage may be calculated regardless of the presence or absence.

Next, an example of the operation of the phase voltage calculation device 2 will be described with reference to the flowchart of FIG.
(Step S101) The line voltage measuring unit 21 measures a plurality of secondary side line voltages. Since the measurement of the secondary side line voltage is continuously performed, it may be considered that the measurement of the plurality of secondary side line voltages means the start of the measurement of the plurality of secondary side line voltages.

(Step S102) The secondary side phase voltage calculation unit 22 calculates the secondary side phase voltage using a plurality of secondary side line voltages. Since the calculation of the secondary side phase voltage is also continuously performed, it may be considered that the calculation of the secondary side phase voltage means the start of the calculation of the secondary side phase voltage.

(Step S103) The difference voltage measuring unit 23 measures the difference voltage between the primary side phase voltage and the secondary side phase voltage. The primary side phase voltage and the secondary side phase voltage are voltages of the same phase. Further, the phase and the phase of the secondary side phase voltage calculated in step S102 may be the same. Since the measurement of the difference voltage is also continuously performed, it may be considered that measuring the difference voltage means starting the measurement of the difference voltage.

(Step S104) The primary side phase voltage calculation unit 24 uses the secondary side phase voltage calculated by the secondary side phase voltage calculation unit 22 and the difference voltage measured by the difference voltage measurement unit 23 to the primary side. Calculate the phase voltage. Since the calculation of the primary side phase voltage is also continuously performed, it may be considered that the calculation of the primary side phase voltage means the start of the calculation of the primary side phase voltage.

The power transmission direction is determined using the secondary side phase voltage calculated in step S102 and the primary side phase voltage calculated in step S104. After the determination is made, the line voltage measuring unit 21 measures the secondary side line voltage, the secondary side phase voltage calculating unit 22 calculates the secondary side phase voltage, and the difference voltage measuring unit 23 measures the difference voltage. The measurement and the calculation of the primary side phase voltage by the primary side phase voltage calculation unit 24 may be completed. Further, the order of processing in the flowchart of FIG. 2 is an example, and the order of each step may be changed as long as the same result can be obtained.

Further, in the above embodiment, the case where the phase voltage is calculated for one phase has been mainly described, but it is not necessary. The phase voltage may be calculated for a plurality of phases. In that case, the line voltage measuring unit 21 measures the three secondary side line voltages, and the secondary side phase voltage calculating unit 22 calculates the secondary side phase voltages of a plurality of phases and measures the difference voltage. The unit 23 may measure the difference voltage of a plurality of phases, and the primary side phase voltage calculation unit 24 may calculate the primary side phase voltage of the plurality of phases. The three secondary side line voltages are the line voltages between all the phases on the secondary side. Further, the plurality of phases may be two phases or three phases. Further, a plurality of phases in which the secondary side phase voltage calculation unit 22 calculates the secondary side phase voltage, a plurality of phases in which the difference voltage measurement unit 23 measures the difference voltage, and the primary side phase voltage calculation unit 24 are on the primary side. It may be the same as a plurality of phases for which the phase voltage is calculated. When calculating a plurality of secondary side phase voltages using the three secondary side line voltages, the secondary side phase voltage calculation unit 22 uses different secondary side lines to calculate each secondary side phase voltage. It is preferable to use a combination of inter-voltages. For example, the secondary side phase voltage calculation unit 22 may calculate the secondary side phase voltage of the three phases by the following equation.
_{V 2U = 2/3 × (} V 2UV + 1/2 × V 2VW)
V _2V = 2/3 x (V _2VW + 1/2 x V _2WU )
_{V 2W = 2/3 × (} V 2WU + 1/2 × V 2UV)

As described above, when the primary side phase voltage and the secondary side phase voltage for the plurality of phases are calculated, the determination unit 14 may make a determination for each phase. Then, the determination unit 14 may specify the final determination result by, for example, a majority vote. By doing so, more accurate determination becomes possible. Further, the determination unit 14 uses, for example, when the determination results for each phase match, and when the determination results for each phase do not match, that is, the determination result for at least one phase is the other phase. If it is different from the judgment result of, the judgment result may not be used. When the determination results for each phase do not match, the determination unit 14 may use the latest determination result among the determination results for which the determination results for each phase match as the determination result at that time. By doing so, the determination result with low accuracy is not used, and as a result, the determination with high accuracy becomes possible. When using the past determination results in this way, at least the latest determination results may be stored in a recording medium (not shown). The determination result is a determination result when the determination results for each phase match. When the primary side phase voltage and the secondary side phase voltage for all phases are calculated, the line voltage measuring unit 21 measures the three line voltages, and the difference voltage measuring unit 23 measures all the phases. It is preferable to use the difference voltage of. This is because it is possible to calculate the phase voltage with high accuracy. On the other hand, even when the line voltage measuring unit 21 measures the two secondary side line voltages and the differential voltage measuring unit 23 measures the two differential voltages, the primary side phase voltage and the secondary are related to all the phases. It can be calculated with the side phase voltage. When two secondary side line voltages are measured, the remaining one secondary side line voltage can be calculated using the two secondary side line voltages, and the two differential voltages can be used. This is because when the two primary side phase voltages are calculated, the remaining one primary side phase voltage can be calculated using the two primary side phase voltages.

As described above, according to the automatic voltage transformer 1 according to the present embodiment, the secondary side phase voltage can be calculated using the secondary side line voltage, and the secondary side phase voltage and the difference voltage can be calculated. Since the primary side phase voltage can be calculated by using it, it is not necessary to use a voltage transformer for measuring the secondary side phase voltage. Further, since the line voltage is usually used for the voltage adjustment in the SVR, the automatic voltage regulator 1 has the line voltage measuring unit 21 regardless of whether or not the phase voltage is calculated. .. Therefore, in the automatic voltage transformer 1 according to the present embodiment, the primary side phase voltage and the secondary side phase voltage required for determining the transmission direction can be calculated and measured by effectively using the line voltage measuring unit 21. Compared with the case where the primary side phase voltage is calculated using the secondary side phase voltage and the difference voltage (that is, in the case of Patent Document 2 above), the primary side phase is used with a smaller number of voltage transformers. The voltage and the secondary side phase voltage can be obtained. In addition, the power transmission direction can be determined using the primary side phase voltage and the secondary side phase voltage, and tap switching control is performed using the determination result to realize more appropriate voltage adjustment in SVR. can do.

In the above embodiment, the case where the primary side phase voltage calculated by the phase voltage calculation device 2 is used for determining the power transmission direction in the automatic voltage regulator 1 has been described, but it is not necessary. The primary side phase voltage calculated by the phase voltage calculation device 2 may be used for a purpose other than the determination of the power transmission direction in the automatic voltage regulator 1.

Further, in the above embodiment, each process or each function may be realized by centralized processing by a single device or a single system, or distributed processing by a plurality of devices or a plurality of systems. It may be realized by.

Further, in the above embodiment, the transfer of information performed between the components is performed by, for example, one component when the two components that transfer the information are physically different. It may be performed by outputting information and accepting information by the other component, or if the two components that pass the information are physically the same, one component. It may be performed by moving from the processing phase corresponding to the above to the processing phase corresponding to the other component.

Further, in the above embodiment, information related to the processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component. In addition, information such as threshold values, mathematical formulas, and addresses used by each component in processing may be temporarily or for a long period of time in a recording medium (not shown) even if it is not specified in the above description. In addition, each component or a storage unit (not shown) may store information on a recording medium (not shown). Further, the information may be read from the recording medium (not shown) by each component or a reading unit (not shown).

Further, in the above embodiment, when the information used in each component or the like, for example, the information such as the threshold value and the address used in the processing by each component and various setting values may be changed by the user, the above The information may or may not be changed as appropriate by the user, even if not specified in the description. When the information can be changed by the user, the change is realized by, for example, a reception unit (not shown) that receives a change instruction from the user and a change unit (not shown) that changes the information in response to the change instruction. You may. The reception unit (not shown) may accept the change instruction from, for example, an input device, information transmitted via a communication line, or information read from a predetermined recording medium. ..

Further, among the components described in the above-described embodiment, the components that can be realized by software may be realized by executing the program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. Further, the program may be executed by being downloaded from a server or the like, or may be executed by reading a program recorded on a predetermined recording medium (for example, a magnetic disk, a semiconductor memory, etc.).

Further, it goes without saying that the present invention is not limited to the above embodiments, and various modifications can be made, and these are also included in the scope of the present invention.

From the above, according to the phase voltage calculation device or the like according to the present invention, it is possible to obtain the primary side phase voltage and the secondary side phase voltage by using a small number of voltage transformers. For example, an automatic voltage can be obtained. It is useful as a device for calculating the primary side phase voltage and the secondary side phase voltage in a regulator.

1 Automatic voltage regulator 2 Phase voltage calculation device 11 Adjustment transformer 12 Tap switch 13 Tap switching controller 14 Judgment unit 21 Line voltage measurement unit 22 Secondary side phase voltage calculation unit 23 Difference voltage measurement unit 24 Primary side phase voltage Calculation unit

Claims (4)

It is a phase voltage calculation device that calculates the primary side phase voltage and the secondary side phase voltage of a regulating transformer having multiple taps.
A line voltage measuring unit that measures a plurality of secondary side line voltages of the adjusting transformer,
A secondary side phase voltage calculation unit that calculates the secondary side phase voltage using the plurality of secondary side line voltages, and
A differential voltage measuring unit that measures the differential voltage, which is the difference between the primary side phase voltage and the secondary side phase voltage,
A phase voltage calculation device including a primary side phase voltage calculation unit that calculates a primary side phase voltage using the secondary side phase voltage calculated by the secondary side phase voltage calculation unit and the difference voltage. The phase voltage calculation device according to claim 1, wherein the secondary side phase voltage calculation unit calculates the secondary side phase voltage by the following equation.
V _2V = 2/3 x (V _2VW + 1/2 x V _2WU )
(In the equation, V _2V is the secondary side line voltage of the second phase, V _2VW is the secondary side line voltage between the second phase and the third phase, and V _2WU is the third phase. The voltage between the secondary siding and the first phase.) The line voltage measuring unit measures three secondary side line voltages and measures them.
The secondary side phase voltage calculation unit calculates the secondary side phase voltage of a plurality of phases, and calculates the secondary side phase voltage.
The difference voltage measuring unit measures the difference voltage of a plurality of phases and measures the difference voltage.
The phase voltage calculation device according to claim 1 or 2, wherein the primary side phase voltage calculation unit calculates primary side phase voltages of a plurality of phases. The phase voltage calculation device according to any one of claims 1 to 3.
With the adjusting transformer
A tap switch that switches the energizing tap of the adjustment transformer, and
The amount of change in the primary side phase voltage calculated by the primary side phase voltage calculation unit and the secondary side phase voltage calculated by the secondary side phase voltage calculation unit when the energizing tap is switched by the tap switcher. A judgment unit that determines the power transmission direction using the amount of change in
An automatic voltage regulator including a tap switching controller that controls the tap switching device according to a power transmission direction determined by the determining unit and a voltage of the adjusting transformer.

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