JP6755813B2 - Primary voltage calculator and automatic voltage regulator - Google Patents

Description

The present invention includes a primary side voltage calculation device that calculates the primary side voltage using the secondary side voltage of the transformer and the difference between the primary side voltage and the secondary side voltage, and a primary side voltage calculation device thereof. Regarding automatic voltage regulators.

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. Therefore, a complete reverse feed type SVR (bidirectional voltage adjustment type SVR) that adjusts the secondary side voltage at the time of forward feed and adjusts the primary side voltage at the time of reverse feed is also known.

In such a complete reverse feed type SVR, an instrument transformer (VT) is usually used to measure each of the primary side voltage and the secondary side voltage, and the secondary side voltage is used at the time of progressive feed. The voltage was adjusted, and the voltage was adjusted using the primary side voltage at the time of reverse transmission.
For a purpose different from voltage adjustment, 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 (see Patent Document 1). ..

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 1, the primary side voltage is calculated by using the difference between the primary side phase voltage and the secondary side phase voltage. Therefore, in order to calculate the primary lateral line voltage using the technique described in Patent Document 1, vector calculation of the voltage for a plurality of phases is required. In the vector calculation, there is a problem that the calculation load becomes large in order to reduce the error and improve the accuracy. On the other hand, if the calculation load is reduced, there is a problem that the error increases.
Generally speaking, when calculating the primary side line voltage of a regulating transformer using the secondary side voltage and the difference between the primary side voltage and the secondary side voltage, the calculation load is reduced and the accuracy is improved. There was a problem that it was not possible to achieve both.

The present invention has been made to solve the above problems, and provides a primary side voltage calculation device or the like capable of calculating the primary side line voltage with high accuracy without increasing the calculation load. The purpose.

In order to achieve the above object, the primary side voltage calculation device according to the present invention is a primary side voltage calculation device that calculates the primary side line voltage of an adjustment transformer having a plurality of taps, and is a plurality of secondary side voltage calculation devices of the adjustment transformer. A line voltage measuring unit that measures the side line voltage, a phase voltage calculating unit that calculates the secondary side phase voltage using a plurality of secondary side line voltages, and a primary side phase voltage and a secondary side phase voltage. A phase difference measuring unit that measures the phase difference between the difference voltage measuring unit that measures the difference voltage, the secondary side phase voltage calculated by the phase voltage calculating unit, and the difference voltage measured by the difference voltage measuring unit. Then, the difference voltage is normalized so that the result of converting the magnitude of the difference voltage into the line voltage is the tap voltage of the adjustment transformer, and the phase difference is 0 ° or 180 °. The secondary of the absolute value of the difference between the number of primary side turns and the number of secondary side turns according to the energizing tap of the adjustment transformer, using the normalization part that normalizes the voltage and the value after normalization regarding the difference voltage. The primary side line is used by the specific part that specifies the turn number difference ratio, which is the ratio to the side turn number, the secondary side line voltage, the turn number difference ratio specified by the specific part, and the phase difference after normalization. It is provided with a primary side voltage calculation unit for calculating the inter-voltage.
With such a configuration, it becomes possible to calculate the primary lateral line voltage with high accuracy by performing normalization without performing highly accurate vector calculation. Therefore, in calculating the primary lateral line voltage, it is possible to reduce the calculation load and improve the accuracy at the same time.

Further, in the primary side voltage calculation device according to the present invention, the line voltage measuring unit measures the three secondary side line voltages, and the phase voltage calculating unit calculates the secondary side phase voltages of a plurality of phases, and the difference is obtained. The voltage measuring unit measures the difference voltage of a plurality of phases, the phase difference measuring unit measures the phase difference of a plurality of phases, and the normalizing unit normalizes the multiple phases, and the result of the normalization is obtained. An abnormality detection unit that detects an abnormality when the phases are different from each other, and an output unit that outputs an output related to the detection of the abnormality when the abnormality is detected by the abnormality detection unit may be further provided.
With such a configuration, it becomes possible to detect an abnormality related to the adjustment transformer or the like by using the difference voltage or the phase difference after normalization.

Further, in the primary side voltage calculation device according to the present invention, the current measuring unit for measuring the secondary side current, the secondary side current, the turn number difference ratio specified by the specific unit, and the phase difference after normalization are obtained. It may be further provided with a primary side current calculation unit for calculating the primary side current.
With such a configuration, it becomes possible to calculate the primary side current by using the secondary side current.

Further, the automatic voltage regulator according to the present invention is provided with a primary side voltage calculation device, and when performing voltage adjustment on the primary side, the primary side line voltage calculated by the primary side voltage calculation device is used.

According to the primary side voltage calculation device or the like according to the present invention, it is possible to reduce the calculation load and improve the accuracy in calculating the primary side line voltage at the same time.

A block diagram showing a configuration of an automatic voltage regulator according to an embodiment of the present invention. A block diagram showing the configuration of the automatic voltage regulator of the first modification in the same embodiment. A block diagram showing the configuration of the automatic voltage regulator of Modification 2 in the same embodiment. A flowchart showing the operation of the primary voltage calculation device in the same embodiment. A flowchart showing the operation of the primary side voltage calculation device of the first modification in the same embodiment. A flowchart showing the operation of the primary side voltage calculation device of the modification 2 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 primary side voltage calculation device according to the present invention and the automatic voltage regulator including the primary side voltage calculation device will be described with reference to the embodiments. In the following embodiments, the components and steps having the same reference numerals are the same or correspond to each other, and the description thereof may be omitted again. The automatic voltage regulator according to the present embodiment normalizes the primary side line voltage of the adjusting transformer when calculating it using the secondary side line voltage and the difference between the primary side phase voltage and the secondary side phase voltage. It is equipped with a primary side voltage calculation device for performing the above.

FIG. 1A is a block diagram showing a configuration of the 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 primary side voltage calculating device 2. The primary side voltage calculation device 2 calculates the primary side line voltage of the adjustment transformer 11, and includes the line voltage measurement unit 21, the phase voltage calculation unit 22, the difference voltage measurement unit 23, and the phase difference measurement unit. 24, a normalization unit 25, a specific unit 26, and a primary side voltage calculation unit 27 are provided. The automatic voltage regulator 1 may be a complete reverse feed type SVR that adjusts the secondary side voltage at the time of forward feed and adjusts the primary side voltage at the time of reverse feed. Then, the automatic voltage regulator 1 may perform the automatic voltage adjustment using the primary side line voltage calculated by the primary side voltage calculation device 2 at the time of voltage adjustment on the primary side, that is, at the time of reverse feed.

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 other phases have the same configuration. 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 tap tp2 is turned on by the tap switch 12a, tap tp9 to tap tp5 are shunt windings, and tap tp5 to tap tp2 are serial windings, which are primary. The secondary side will be stepped down with respect to the side. The tap switch 12a can adjust the voltage on the output side by switching the position of the tap on which the switch is 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. The tap switching controller 13 may control the tap switching controller 12 so as to keep the primary side line voltage of the adjusting transformer 11 at the target voltage at the time of reverse transmission. Therefore, the tap switching controller 13 may output a tap switching command to the tap switching device 12 by using the primary side line voltage calculated by the primary side voltage calculating unit 27. Even at that time, even if the tap switching controller 13 controls so that the primary side line voltage corrected by using the voltage drop in the primary side distribution line 4 predicted by using the primary side current becomes the target voltage. Good. The primary side current used for predicting the voltage drop on the primary side may be a measured one or a calculated one as in the second modification described later. 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. 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 may determine the direction of the substation by using, for example, the magnitude of the amount of change between the primary side voltage and the secondary side voltage at the time of tap switching. This is because the voltage fluctuation corresponding to the tap switching is usually small on the side where the substation exists and large on the side where the substation does not exist. An improved method of the determination method is described in, for example, Japanese Patent Application Laid-Open No. 2000-295774. A method of determining the power transmission direction using the magnitude of the change in the primary voltage and the change in the secondary 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 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 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. 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. The vector V _2VW corresponds to the secondary lateral line voltage between the 2V phase and the 2W phase, and the vector V _2WU corresponds to the secondary lateral line voltage between the 2W phase and the 2U phase. There is.

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 )

When the secondary side line voltages V _2VW and V _2WU are measured by the line voltage measuring unit 21, the phase voltage calculating unit 22 uses those line voltages to obtain the secondary side 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. 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.

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.

なお、平均は、１秒以外の時間間隔における平均であってもよい。また、平均を算出しないで、１サイクルの値をそのまま用いてもよい。それらのことは、以下の説明において他の値の平均が算出される場合にも同様であるとする。 The phase difference measuring unit 24 measures the phase difference between the secondary side phase voltage calculated by the phase voltage calculating unit 22 and the difference voltage measured by the difference voltage measuring unit 23. The phase difference measuring unit 24 _acquires , for example, a phase difference according to the angle formed by the vector V _2V shown in FIG. 6 and the vector V _{1V 2V} . Theoretically, the angle between the two vectors is 0 ° or 180 °, so the phase difference should be 0 ° or 180 °, but in reality, due to an unbalanced load, the measured phase difference is also 0. It may deviate from ° or 180 °. When the phase difference is 0 °, the step is stepped down by the adjusting transformer 11, and when the phase difference is 180 °, the step is stepped up by the adjusting transformer 11. The phase difference may be measured, for example, by counting the zero cross interval of each voltage with a timer, or by counting the peak interval of each voltage with a timer. For example, the phase difference (deg) is the result of dividing the zero-cross time interval and the peak time interval by one cycle of three-phase alternating current and multiplying by 360 °. The detection of zero crossing of voltage may be performed, for example, by comparing the target voltage with 0 (V) by a comparator, or by detecting the change timing of the sign of the target voltage. Good. Note that measuring the phase difference may mean measuring the magnitude of the phase difference. The phase difference measuring unit 24 may measure the average of the phase difference between the secondary side phase voltage and the difference voltage as the phase difference. The average may be, for example, a 1-second average. That is, the phase difference measuring unit 24 may calculate the phase difference ε by using the phase difference ε (m) for each cycle for one second as shown in the following equation. In the case of western Japan, the 1-second average is a 60-cycle average, so m is an integer from 1 to 60.

The average may be an average at a time interval other than 1 second. Further, the value of one cycle may be used as it is without calculating the average. It is assumed that the same applies to the case where the average of other values is calculated in the following description.

The normalization unit 25 normalizes the difference voltage so that the result of converting the magnitude of the difference voltage measured by the difference voltage measurement unit 23 into the line voltage becomes the inter-tap voltage of the adjustment transformer 11. As described above, the difference voltage measured by the difference voltage measuring unit 23 is a value that fluctuates with time. Therefore, the normalization unit 25 calculates the average of the effective values of the difference voltage, and even if the normalization is performed so that the result of converting the average of the effective values of the difference voltage into the line voltage becomes the inter-tap voltage. Good. That is, the magnitude of the difference voltage may be the average value of the effective values of the difference voltage. The calculation of the effective value V _{1V 2V} rms of the difference voltage V _{1V 2V} may be performed as follows, for example. Note that V _1V2V (t) is an instantaneous value of the difference voltage at the sampling time point t, and is a value measured by the difference voltage measuring unit 23. It is assumed that sampling of the difference voltage from t = 1 to h is performed in one cycle. Here, assuming that the sampling time interval is Δt, Δt × h is a cycle of one cycle.

_Further , the calculation of the average value V _{1V 2 Vave} using the effective value may be performed as follows, for example. In the following equation, the 1-second average of the effective value V _{1V 2 Vrms} of the difference voltage, that is, the 60-cycle average is calculated.

Conversion to line voltage magnitude V _1V2Vave differential voltage may be performed by multiplying the √3 to V _1V2Vave. In addition, √3 means 3 ^1/2 . If the three phases are in equilibrium, then the magnitude of the differential voltage V _{1V 2 Vave} can be converted to the line voltage. On the other hand, when the three phases are not in equilibrium, if the phase voltage is converted to the line voltage by multiplying it by √3, the conversion result will include an error, but it is normalized to the conversion result. By doing so, the influence of the error disappears. The inter-tap voltage of the adjusting transformer 11 is the magnitude of the voltage that changes when the energizing tap of the adjusting transformer 11 is changed. For example, assuming that the primary side voltage of the adjusting transformer 11 is constant, the magnitude of the secondary side voltage that changes each time the energizing tap is switched becomes the inter-tap voltage. The voltage between taps is a real number of 0 or more. The voltage between taps is preferably an integral multiple of the voltage between taps (tap width). For example, _assuming that the voltage between taps is V _TPrms , it is preferable that the voltage between taps is n × V _TPrms (n is an integer of 0 or more). The voltage between taps is also the voltage between lines. Hereinafter, the value of n may be referred to as a tap interval.

Further, the normalization may be to change the value to be normalized to the value closest to the value to be normalized among a plurality of predetermined values. When there are two values closest to the value to be normalized in the plurality of predetermined values, that is, the value to be normalized is included in the plurality of predetermined values. If it is exactly in the middle of the two values, it may be normalized to either side with respect to the value to be normalized. It should be noted that the side to be normalized may be decided in advance.

The process of normalizing the magnitude of the difference voltage to the line voltage to be the tap voltage of the adjustment transformer 11 is the result of converting the magnitude of the difference voltage V _{1V 2 Vave} to the line voltage √ Any processing may be performed as long as 3 × V _1V2Vave results in a tap-to-tap voltage closest to that √3 × V _1V2Vave . The normalization may be performed on, for example, the result of converting the magnitude of the difference voltage into the line voltage, or may be performed on the magnitude of the difference voltage. In the former case, √3 × V _1V2Vave is normalized, and the result of the normalization is the voltage between taps. In the latter case, V _{1V 2 Vave} will be normalized, and the result of the normalization will be one of the tap voltages divided by √3. Specifically, the voltage between taps is an integral multiple of the voltage between taps, the voltage between taps is 75 (V _rms ), and the magnitude of the difference voltage is converted into the line voltage √3 × When V _{1V 2 Vave} is the target of normalization, the line voltage 170 (V _rms ) to be normalized will be normalized to 150 (V _rms ). In that case, the plurality of predetermined values are 0,75,150,225, ... (V _rms ), and the closest to the line voltage 170 (V _rms ) to be normalized is 150 (V _rms ). This is because it is V _rms ). By using the normalized value, it is possible to know the tap interval (n) between the primary side and the secondary side regarding the energizing tap of the adjusting transformer 11. Therefore, there is a one-to-one correspondence between the normalized value and the tap interval between the primary side and the secondary side or the voltage between taps with respect to the energizing tap.

Further, the normalization unit 25 normalizes the phase difference so that the phase difference ε measured by the phase difference measuring unit 24 is 0 ° or 180 °. ^Let the phase difference after normalization be ε ⁽ⁿ⁾ . Since only the magnitude of the difference voltage (≧ 0) between the primary side and the secondary side can be known from the normalized value regarding the magnitude of the difference voltage, the step-up is performed in the adjusting transformer 11. You will not know if it is or if it is stepping down. On the other hand, the step-up and step-down can be known from the phase difference after normalization. That is, if the phase difference after normalization is 0 °, the step-down is performed, and if the phase difference after normalization is 180 °, the step-up is performed. Needless to say, the phase difference may be indicated by degrees (deg) or radians (rad). Therefore, normalizing the phase difference ε to 0 ° or 180 ° (deg) is the same as normalizing the phase difference ε to 0 or π (rad).

The identification unit 26 specifies the turn number difference ratio according to the energization tap of the adjustment transformer 11 by using the normalized value regarding the difference voltage. Here, the turn number difference ratio according to the energizing tap is the ratio of the absolute value of the difference between the number of primary side turns and the number of secondary side turns according to the energizing tap to the number of secondary side turns. In the adjustment transformer 11 of FIG. 4, when the tap tpk (where k is an integer of 1 to 9) is an energizing tap, the number of primary side turns is n1 _k and the number of secondary side turns is n1 _k. Assuming that n2 _k , the turn number difference ratio Δn is
Δn = | n1 _k −n2 _k | / n2 _k
It may be. The turn number difference ratio will be different for each energizing tap. The turn number difference ratio and the tap interval between the primary side and the secondary side or the voltage between taps with respect to the energizing tap of the adjusting transformer 11 have a one-to-one correspondence. Therefore, as a result, there is a one-to-one correspondence between the normalized value of the difference voltage and the turn number difference ratio. Therefore, the identification unit 26 can specify the turn number difference ratio by using the normalized value regarding the difference voltage. The identification unit 26 corresponds to the normalized value of the differential voltage by using, for example, information that associates the normalized value of the differential voltage with the turn number difference ratio on a one-to-one basis (for example, a table that associates the two). You may specify the difference ratio of the number of turns to be performed. The turn number difference ratio may be specified, for example, by accumulating the turn number difference ratio of the specific target in the recording medium, and information such as a flag is set in association with the turn number difference ratio of the specific target. It may be done by.

The normalization of the difference voltage and the specification of the turn number difference ratio using the result of the normalization may be collectively performed as a series of processes. Since there is a one-to-one correspondence between the normalized value for the differential voltage and the turn number difference ratio, the normalized value for the differential voltage is specified, and the turn corresponding to the specified normalized value is specified. Instead of specifying the number difference ratio, it is also possible to directly specify the turn number difference ratio corresponding to the normalized value of the difference voltage by using the magnitude of the difference voltage. Further, as will be described later, it is not the normalized phase difference ε ⁽ⁿ⁾ itself but cos (ε ⁽ⁿ⁾ ) that is used in the calculation of the primary lateral line voltage. Therefore, the normalization of the phase difference and the calculation of cos (ε ⁽ⁿ⁾ ) using the result of the normalization ε ⁽ⁿ⁾ may be collectively performed as a series of processes. Since the result of phase difference normalization ε ⁽ⁿ⁾ and cos (ε ⁽ⁿ⁾ ) have a one-to-one correspondence, the phase difference ε ⁽ⁿ⁾ after normalization is specified, and the specified normality is specified. Instead of calculating the cos (ε ⁽ⁿ⁾ ) corresponding to the phase difference after conversion, the phase difference ε is used to directly calculate the cosine (cos) of the phase difference ε ⁽ⁿ⁾ after normalization. It is also possible. As described above, normalization is indirect when the number of turns difference ratio is specified directly from the magnitude of the difference voltage, or when the cosine of the phase difference after normalization is calculated directly from the phase difference. Will be done in. Therefore, it may be considered that the above-mentioned normalization regarding the difference voltage and the normalization of the phase difference by the normalization unit 25 include those indirectly performed as such.

The primary side voltage calculation unit 27 uses the secondary side line voltage V _2VW , the turn number difference ratio Δn specified by the specific unit 26, and the normalized phase difference ε ⁽ⁿ⁾ as shown in the following equation. The primary side line voltage V _1VW between the 1V phase and the 1W phase is calculated.
V _1VW = V _2VW + cos (ε ⁽ⁿ⁾ ) × Δn × V _2VW

Here, V _2VW may be the average of the effective values of the line voltage between the V phase and the W phase on the secondary side measured by the line voltage measuring unit 21. The average of the effective values may be calculated in the same manner as, for example, V _{1V 2 Vave} . When the secondary side line voltage used in the above equation is an effective value, the calculated primary side line voltage is also an effective value. The primary side line voltage calculated by the primary side voltage calculation unit 27 may be used when adjusting the primary side voltage of the adjusting transformer 11 as described above. In that case, the calculated primary lateral line voltage may be output to the tap switching controller 13. Further, the calculated primary lateral line voltage may be used for other purposes. Further, the secondary side line voltage used by the primary side voltage calculation unit 27 for calculating the primary side line voltage may be measured by the line voltage measurement unit 21, or may be calculated. May be good. Since a plurality of line voltages are measured by the line voltage measuring unit 21, even if the line voltage between a certain phase is not measured, the unmeasured line voltage can be used as the other two line voltages. It can be calculated using the measurement result of. Specifically, when the secondary side inter-line voltage V _2VW, V _2WU is measured, it is possible to calculate the secondary side inter-line voltage V _{2 UV} using a secondary side inter-line voltage V _2VW, V _2WU .. Therefore, the primary side voltage calculation unit 27 may calculate the primary side line voltage by using the secondary side line voltage which is the calculation result. The primary-side voltage calculation unit 27 may calculate the primary side inter-line voltage V _1WU between as described above may be calculated primary side inter-line voltage V _1VW, 1W phase and 1U phase, 1U The primary lateral line voltage V _1UV between the phase and the 1V phase may be calculated, or the primary lateral line voltage of any two or more combinations thereof may be calculated. For example, the primary side voltage calculation unit 27 may calculate three primary side line voltages, that is, all primary side line voltages.

The primary side voltage calculation device 2 may calculate the primary side line voltage only at the time of reverse feed for adjusting the voltage on the primary side, or the primary side line voltage regardless of whether it is forward feed or reverse feed. May be calculated.

Next, an example of the operation of the primary side voltage calculation device 2 shown in FIG. 1A will be described with reference to the flowchart of FIG. 2A.
(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 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 phase difference measuring unit 24 measures the phase difference between the calculated secondary side phase voltage and the measured difference voltage. The measurement of the phase difference may be, for example, a measurement of the average value of the phase difference.

(Step S105) The normalization unit 25 performs normalization regarding the difference voltage and normalization of the phase difference. The difference voltage may be, for example, the average value of the effective values.

(Step S106) The identification unit 26 specifies the turn number difference ratio by using the result of normalization regarding the difference voltage.

(Step S107) The primary side voltage calculation unit 27 calculates the primary side line voltage using the secondary side line voltage, the turn number difference ratio, and the normalized phase difference. The primary side line voltage is the same line voltage as the secondary side line voltage used for the calculation. The secondary lateral line voltage may be, for example, an average value of effective values. The calculated primary side line voltage may be used for voltage adjustment on the primary side.

In the flowchart of FIG. 2A, for example, the processes of steps S104 to S107 may be repeatedly executed during the period of reverse power transmission. Further, when the calculation of the primary side line voltage is completed, for example, when the reverse power transmission is switched to the forward power transmission, the line voltage measuring unit 21 measures the secondary side line voltage, and the phase voltage calculating unit 22 performs the second. The calculation of the next-side phase voltage and the measurement of the difference voltage by the difference voltage measuring unit 23 may be completed. Further, the order of processing in the flowchart of FIG. 2A is an example, and the order of each step may be changed as long as the same result can be obtained.

[Modification 1]
In the above embodiment, the case where normalization is performed only for one phase has been described, but it is not necessary. For example, the normalization unit 25 may normalize a plurality of phases. FIG. 1B is a block diagram showing a configuration of an automatic voltage regulator 1 having a primary side voltage calculation device 2 in which the normalization unit 25 normalizes a plurality of phases. In FIG. 1B, the primary side voltage calculation device 2 includes a line voltage measurement unit 21, a phase voltage calculation unit 22, a difference voltage measurement unit 23, a phase difference measurement unit 24, a normalization unit 25, and a identification unit 26. A primary side voltage calculation unit 27, an abnormality detection unit 31, and an output unit 32 are provided. For configurations and operations other than the abnormality detection unit 31 and the output unit 32, the line voltage measuring unit 21 measures the three secondary side line voltages, and the phase voltage calculation unit 22 measures the secondary side voltage of the plurality of phases. Is calculated, the difference voltage measuring unit 23 measures the difference voltage of a plurality of phases, the phase difference measuring unit 24 measures the phase difference of the plurality of phases, and the normalizing unit 25 normalizes the plurality of phases. Is the same as that of the above embodiment. 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 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 a plurality of phases in which the normalization unit 25 normalizes. May be the same. Further, when calculating a plurality of secondary side phase voltages using the three secondary side line voltages, the phase voltage calculation unit 22 calculates each secondary side phase voltage by using different secondary side line voltages. It is preferable to use a combination. This is so that an abnormality related to each line can be detected. 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)

The abnormality detection unit 31 detects an abnormality when the normalization results differ between the phases. That is, the abnormality detection unit 31 detects an abnormality when the normalization result regarding the difference voltage differs between the phases, and detects an abnormality when the normalization result regarding the phase difference differs between the phases. If the result of the normalization regarding the difference voltage is the same for all phases and the result of the normalization regarding the phase difference is the same for all the phases, the abnormality detection unit 31 will not detect the abnormality. .. Note that all phases mean all phases relating to a plurality of normalized phases. Normally, when the automatic voltage transformer 1 is operating normally, the result of normalization regarding the difference voltage is the same for all phases, and the result of the normalization regarding the phase difference is the same for all phases. It should be, but it may not be the case, for example, when an abnormality has occurred in any of the contacts, the voltage transformer, the adjusting transformer 11, or other components. Therefore, as described above, the abnormality in the automatic voltage regulator 1 can be detected.

When an abnormality is detected by the abnormality detection unit 31, the output unit 32 outputs the abnormality detection. This output may be, for example, displayed on a display device (for example, a liquid crystal display), transmitted via a communication line to a predetermined device, may be audio output by a speaker, or may be stored in a recording medium. It may be handed over to another component. The output unit 32 may or may not include a device that outputs (for example, a display device, a communication device, etc.). Further, the output unit 32 may be realized by hardware, or may be realized by software such as a driver that drives those devices. Further, the output related to abnormality detection may be an output indicating that an abnormality has been detected, or may be an output for predetermined processing, control, or the like according to the detection of the abnormality. The output to the effect that an abnormality has been detected may be output to, for example, the administrator of the automatic voltage regulator 1 or the system that manages the automatic voltage regulator 1. In addition, when an output indicating that an abnormality has been detected is output, for example, information that can identify a phase in which the normalization result does not match the other two phases (for example, one with the other two phases). What was not done is the V phase, etc.) may be included in the output content. Further, when an output for predetermined processing, control, etc. is performed according to the detection of an abnormality, the output unit 32 outputs, for example, an output for passing through and fixing the energizing tap of the adjusting transformer 11. You may go to the tap switching controller 13. Further, when the abnormality is not detected, the output unit 32 may output the fact that the abnormality has not been detected, or may not output such an output. In the former case, for example, when an abnormality is not detected, an output indicating that there is no abnormality, that is, that it is normal may be output, and for processing or control performed when it is normal. Output may be done.

If an abnormality is detected, the abnormality may be detected again after a predetermined time. Then, when an abnormality is continuously detected a predetermined number of times, an output related to the detection of the abnormality may be output. For example, even if the load becomes unbalanced at a certain point in time and an abnormality is detected, the abnormality may not be detected due to the subsequent equilibrium load.

FIG. 2B is a flowchart showing an example of the operation of the primary side voltage calculation device 2 shown in FIG. 1B. In the flowchart of FIG. 2B, in the processes other than steps S201 and S202, the line voltage measuring unit 21 measures the three secondary side line voltages, and the phase voltage calculating unit 22 calculates the secondary side voltage of the plurality of phases. Then, except that the difference voltage measuring unit 23 measures the difference voltage of a plurality of phases, the phase difference measuring unit 24 measures the phase difference of the plurality of phases, and the normalizing unit 25 normalizes the plurality of phases. It is the same as the flowchart of FIG. 2A, and the description thereof will be omitted.

(Step S201) The abnormality detection unit 31 determines whether or not the normalization results match between the phases. Then, when the normalization results match between the phases, the process proceeds to step S106, and when there is no match between the phases, that is, when there is a difference between the phases for at least one of the difference voltage and the phase difference. Goes to step S202.

(Step S202) The output unit 32 outputs the abnormality detection. Then, the series of processes is completed.
In the flowchart of FIG. 2B, when an abnormality is detected, the primary lateral line voltage is not calculated, but it is not necessary. Even if an abnormality is detected, the primary lateral line voltage may be calculated. In that case, the process may proceed from step S202 to step S106. When an abnormality is detected, the normalization result differs between the phases. Therefore, the specific unit 26 and the primary side voltage calculation unit 27 may perform processing using the predetermined phase normalization result, and the normalization result common to the normalization results of other phases. Processing may be performed using the result.

Further, in the first modification, the case where the abnormality is detected by using both the result of the normalization regarding the difference voltage and the result of the normalization regarding the phase has been described, but this may not be the case. Anomaly detection may be performed using only the result of one of the normalizations.

[Modification 2]
The primary side voltage calculation device 2 may also calculate the primary side current. FIG. 1C is a block diagram showing a configuration of a primary side voltage calculation device 2 that also calculates a primary side current. In FIG. 1C, the primary side voltage calculation device 2 includes a line voltage measurement unit 21, a phase voltage calculation unit 22, a difference voltage measurement unit 23, a phase difference measurement unit 24, a normalization unit 25, and a identification unit 26. A primary side voltage calculation unit 27, a current measurement unit 41, and a primary side current calculation unit 42 are provided. The configuration and operation other than the current measuring unit 41 and the primary side current calculating unit 42 are the same as those in the above embodiment.

The current measuring unit 41 measures the secondary side current. When the adjusting transformer 11 has a star connection, the phase current and the line current are equal to each other. Therefore, the secondary side current to be measured may be considered to be the secondary side phase current, and the secondary side line current may be used. You may think that there is. The current measuring unit 41 may measure one secondary side current, may measure two secondary side currents, or may measure three secondary side currents. The current measuring unit 41 may calculate the average of the measured effective values of the secondary current. The average of the effective values may be calculated in the same manner as, for example, V _{1V 2 Vave} . When the tap switching controller 13 performs control using the secondary lateral line voltage, for example, the output of the current transformer that detects the load current is input to the LDC as described above. Therefore, the current measuring unit 41 may measure the secondary side current using the output of the current transformer, for example, or may measure the secondary side current using the output of another current transformer. ..

The primary side current calculation unit 42 uses the secondary side current I _2V of the 2V phase, the turn number difference ratio Δn specified by the specific unit 26, and the normalized phase difference ε ⁽ⁿ⁾ to obtain the following equation. The 1V phase primary side current I _1V is calculated as described above. The secondary side current I _2V may be the average of the effective values of the secondary side currents of the 2V phase.
I _1V = I _2V / {1 + cos (ε ⁽ⁿ⁾ ) × Δn}

When the secondary side current used in the above equation is an effective value, the calculated primary side current is also an effective value. The primary side current calculated by the primary side current calculation unit 42 may be used, for example, for predicting a voltage drop when adjusting the voltage on the primary side of the adjusting transformer 11, and determines the power transmission direction (substation direction). It may be used for load distribution for each phase, or it may be used for monitoring the primary side voltage of the automatic voltage regulator 1. Further, the secondary side current used by the primary side current calculation unit 42 for calculating the primary side current may be measured by the current measurement unit 41, or may be calculated using the measurement result. You may. Further, the primary side current calculation unit 42 may calculate the primary side current I _1V as described above, or may calculate the 1U phase primary side current I _{1U, and} may calculate the 1W phase primary side current I _1W . It may be calculated, or the primary side current of any two or more combinations thereof may be calculated. The primary side current calculation unit 42 may calculate the primary side current only at the time of reverse feed for adjusting the voltage on the primary side, or calculate the primary side current regardless of whether it is forward feed or reverse feed. May be done.

FIG. 2C is a flowchart showing an example of the operation of the primary side voltage calculation device 2 shown in FIG. 1C. In the flowchart of FIG. 2C, the processes other than steps S301 and S302 are the same as those of the flowchart of FIG. 2A, and the description thereof will be omitted.

(Step S301) The current measuring unit 41 measures the secondary side current. The measurement of the secondary side current may be, for example, a measurement of the average of the effective values of the secondary side current.

(Step S302) The primary side current calculation unit 42 calculates the primary side current using the secondary side current, the turn number difference ratio, and the normalized phase difference. The primary side current is a current having the same phase as the secondary side current used for the calculation.

Although the modified examples 1 and 2 have been described, they may be combined. That is, in the primary side voltage calculation device 2, both the abnormality detection and the calculation of the primary side current may be performed. In that case, the primary side voltage calculation device 2 includes a line voltage measurement unit 21, a phase voltage calculation unit 22, a difference voltage measurement unit 23, a phase difference measurement unit 24, a normalization unit 25, and a specific unit. 26, a primary side voltage calculation unit 27, an abnormality detection unit 31, an output unit 32, a current measurement unit 41, and a primary side current calculation unit 42 may be provided.

As described above, according to the automatic voltage regulator 1 according to the present embodiment, the primary side line voltage can be made highly accurate by normalizing the difference voltage and the phase difference without performing the highly accurate vector calculation. Can be calculated in. Therefore, in the calculation of the primary lateral line voltage, it is possible to reduce the calculation load and improve the accuracy at the same time. Further, when normalization for a plurality of phases is performed as in the first modification, abnormality detection can be performed by using the result of the normalization. Then, when an abnormality is detected, for example, the abnormality can be notified to the administrator or the like, or the energizing tap of the adjusting transformer 11 can be fixed through. Further, when the secondary side current is measured as in the modified example 2, the primary side current can be calculated by using the secondary side current. In that case, it is not necessary to measure the primary side current separately. Further, even if the adjusting transformer 11 cannot detect the current position of the energizing tap, the primary side voltage calculation device 2 can calculate the primary side voltage. Further, since the control target of the automatic voltage regulator 1 is the line voltage, the primary side voltage can be calculated according to the actual condition of the SVR by calculating the primary side line voltage by the primary side voltage calculation unit 27. Become.

In the above embodiment, the case where the primary side line voltage calculated by the primary side voltage calculation device 2 is used for adjusting the primary side line voltage in the automatic voltage regulator 1 has been described, but it is not the case. May be good. The primary side line voltage calculated by the primary side voltage calculation device 2 may be used for a purpose other than adjusting the primary side line voltage in the automatic voltage regulator 1.

Further, in the above embodiment, the case where the effective value of voltage or current is calculated has been described, but the peak value may be calculated instead of the effective value. When the peak value is calculated, it is preferable to perform normalization or the like according to the peak value.

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 primary side voltage calculation device or the like according to the present invention, in the calculation of the primary side line voltage, it is possible to obtain the effect that both the reduction of the calculation load and the improvement of the accuracy can be obtained. It is useful as a device for calculating the voltage between lateral lines.

1 Automatic voltage regulator 2 Primary voltage calculator 11 Adjustment transformer 12 Tap switch 13 Tap switch controller 14 Judgment unit 21 Line voltage measurement unit 22 Phase voltage calculation unit 23 Difference voltage measurement unit 24 Phase difference measurement unit 25 Regular Chemical unit 26 Specific unit 27 Primary side voltage calculation unit 31 Abnormality detection unit 32 Output unit 41 Current measurement unit 42 Primary side current calculation unit

Claims (4)

A primary side voltage calculator that calculates the primary side line voltage of a regulating transformer with multiple taps.
A line voltage measuring unit that measures a plurality of secondary side line voltages of the adjusting transformer,
A 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 difference measuring unit that measures the phase difference between the secondary side phase voltage calculated by the phase voltage calculating unit and the difference voltage measured by the difference voltage measuring unit.
The difference voltage is normalized so that the result of converting the magnitude of the difference voltage into the line voltage becomes the tap voltage of the adjustment transformer so that the phase difference becomes 0 ° or 180 °. The normalization unit that normalizes the phase difference and
Using the normalized value for the differential voltage, the ratio of the absolute value of the difference between the number of primary side turns and the number of secondary side turns according to the energizing tap of the adjustment transformer to the number of secondary side turns is the number of turns. A specific part that specifies the number difference ratio,
A primary having a primary side voltage calculation unit that calculates a primary side line voltage using the secondary side line voltage, the turn number difference ratio specified by the specific unit, and the phase difference after the normalization. Side voltage calculator. The line voltage measuring unit measures three secondary side line voltages and measures them.
The phase voltage calculation unit calculates the secondary side 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 difference measuring unit measures the phase difference of a plurality of phases and measures the phase difference.
The normalization unit normalizes a plurality of phases and normalizes them.
Anomaly detector that detects anomalies when the normalization results differ between phases,
The primary voltage calculation device according to claim 1, further comprising an output unit that outputs an output related to the detection of the abnormality when an abnormality is detected by the abnormality detection unit. A current measuring unit that measures the secondary current and
A claim further comprising a primary side current calculation unit that calculates a primary side current using the secondary side current, the turn number difference ratio specified by the specific unit, and the phase difference after the normalization. The primary side voltage calculation device according to claim 1 or 2. The primary side voltage calculation device according to any one of claims 1 to 3 is provided.
An automatic voltage regulator that uses the primary side line voltage calculated by the primary side voltage calculation device when adjusting the voltage on the primary side.

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