JP2014187781A - Power transmission state determination device and power transmission state determination method for automatic voltage regulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission state determination device and a power transmission state determination method, capable of determining to which one of a primary side and a secondary side of an SVR a power supply such as a transformer substation for power distribution is connected even when a system voltage changes before and after tap changeover of the SVR.SOLUTION: A power transmission state determination device comprises: average processing parts 53 and 54 respectively calculating average values in predetermined time sections of a primary side voltage and a secondary side voltage of an SVR, respectively; a first voltage change amount calculation processing part 55 calculating a first voltage change amount that is a difference between the average value of the primary side voltage after tap changeover of the SVR, and the average value of the primary side voltage before tap changeover of the SVR; a second voltage change amount calculation processing part 56 calculating a second voltage change amount that is a difference between the average value of the secondary side voltage after tap changeover of the SVR, and the average value of the secondary side voltage before tap changeover of the SVR; and a power transmission state determination processing part 57 determining whether a power distribution system is in a state of forward power transmission or reverse power transmission, on the basis of the first and second voltage change amounts.

Description

  The present invention relates to a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator, and particularly detects whether a power source is connected to a primary side or a secondary side of an automatic voltage regulator installed in a distribution system. The present invention relates to a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator that determines whether the automatic voltage regulator is in a forward power transmission or reverse power transmission state.

  In recent years, distributed power sources such as a photovoltaic power generation (PV) system for home use are becoming widespread and are expected to contribute to the maintenance of the global environment. However, when this distributed power supply is connected to a distribution system, the power demand and supply flow may be locally reversed, which may cause a reverse power flow in the distribution system.

  On the other hand, in the power distribution system, a voltage drop in a forward power flow is assumed, and the supply side voltage is set high in advance so as to compensate for the voltage drop. However, when a reverse power flow occurs, the assumed voltage drop disappears, and the voltage at the point where the distributed power source is connected to the power distribution system rises locally.

  This local voltage increase may spread to the surrounding area and increase the line voltage in the middle of the distribution system. When the degree of increase of the line voltage deviates from the specified tolerance, it causes various troubles. For this reason, voltage regulators, such as an automatic voltage regulator (SVR: Step Voltage Regulator), are provided so that it may intervene in the feeder between the power transmission point in a distribution system, and a consumer's power receiving point. The SVR controls the voltage of the power distribution system so that the received voltage at the power receiving point of the consumer is within a specified allowable range regardless of how the voltage of the power distribution system changes in the step-up and step-down directions. .

When voltage adjustment is performed by SVR, it is necessary to determine whether the distribution substation is connected to the primary side or the secondary side of the SVR in order to prevent the voltage of each part of the distribution system from becoming abnormal. As shown in Table 1, the transmission state in which the distribution substation (distribution A) is connected to the primary side of the SVR is “forward transmission”, and the distribution substation (distribution B is connected to the secondary side of the SVR). ) Is connected to “reverse power transmission”, the power flow through which power passes from the primary side to the secondary side of the SVR is “forward flow”, and the power flow through which power passes from the secondary side of the SVR to the primary side. Is called “reverse current”.

  Conventionally, it is assumed that there is no reverse power flow due to a distributed power source, and forward power transmission and reverse power transmission are determined by a reverse current relay (67 relay) that detects the occurrence of reverse power flow. However, due to the introduction of the above-described distributed power source, there has been a situation where a reverse power flow is generated even in the case of forward power transmission, or a forward power flow is generated even in the case of reverse power transmission.

  Therefore, a device has been proposed in which voltage changes on the primary side and the secondary side before and after the tap switching of the SVR are obtained, and it is determined that the power supply source is connected to the side where the voltage change is smaller (for example, Patent Documents). 1).

  The device disclosed in Patent Document 1 includes a reverse flow relay (67 relay) as a power reverse flow detection device that detects the occurrence of reverse power flow in SVR, and the voltage on the primary and secondary sides of SVR, respectively. First voltage detection device and second voltage detection device that output proportional detection signal voltage, and primary distribution line voltage and secondary side output from first voltage detection device and second voltage detection device The first and second A / D converters that convert the analog signal that provides the distribution line voltage into first and second digital signals and output these digital signals, and a microcomputer are provided.

  Here, the microcomputer calculates the difference in the primary voltage before and after the tap switching of the SVR as the first voltage change, and calculates the difference in the secondary voltage before and after the SVR tap switching as the second voltage change. Calculate as minutes.

  Further, the microcomputer determines that the first voltage change is larger than the second voltage change in a state where the reverse flow of power is detected in the SVR by the reverse relay. It is determined that a reverse power flow has occurred due to system switching in which the primary side of the SVR is disconnected from the power supply source and the secondary side is connected to another power supply source. On the other hand, the microcomputer determines that the second voltage change is larger than the first voltage change in a state where the reverse flow of power is detected in the SVR by the reverse relay. It is determined that a reverse power flow has occurred because the primary side of the SVR is connected to the power supply source and the distributed power source is interconnected on the secondary side.

Japanese Patent No. 3992212

  However, in the method disclosed in Patent Document 1, when the system voltage changes, the voltage change due to tap switching cannot be obtained correctly. As a result, there is a problem that a situation in which the determination of forward transmission and reverse transmission is not performed correctly occurs.

  The present invention has been made to solve the above-described problems, and even when the system voltage changes, a power source such as a distribution substation is provided on either the primary side or the secondary side of the SVR. It is an object of the present invention to provide a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator that can determine whether or not they are connected.

  A power transmission state determination device for an automatic voltage regulator according to the present invention detects whether a power source is connected to a primary side or a secondary side of an automatic voltage regulator of a load tap switching type installed in a distribution system. A power transmission state determination device for determining whether the distribution system is in a forward power transmission or reverse power transmission state, and measuring a primary side voltage and a secondary side voltage of the automatic voltage regulator, respectively. A measurement unit, a secondary side voltage measurement unit, a first average processing unit and a second average processing unit that calculate average values of the primary side voltage and the secondary side voltage in a predetermined time interval, respectively; The average value of the primary side voltage and the automatic voltage regulator after a predetermined time from when the tap switching of the automatic voltage regulator is performed using the average value of the primary side voltage calculated by the average processing unit Is switched A first voltage change calculation processing unit that calculates a first voltage change that is a difference between average values of the primary side voltage at a predetermined time before the time point, and the two calculated by the second average processing unit. The average value of the secondary side voltage and the time point when the tap switching of the automatic voltage regulator is performed after a predetermined time from the time point when the tap switching of the automatic voltage regulator is performed using the average value of the secondary side voltage A second voltage change calculation processing unit for calculating a second voltage change that is a difference between the average values of the secondary side voltages before a predetermined time, and the first voltage change and the second voltage And a power transmission state determination processing unit that determines whether the distribution system is in a forward power transmission state or a reverse power transmission state based on a change.

  According to this power transmission state determination device, the voltage change amount of the primary side voltage and the secondary side voltage before and after the tap switching is calculated based on the average value of the primary voltage and the secondary voltage of the automatic voltage regulator in a predetermined time section. Thus, even when the system voltage changes, it is possible to determine whether the power source such as the distribution substation is connected to the primary side or the secondary side of the automatic voltage regulator.

  In the power transmission state determination device, the first average processing unit and the second average processing unit may calculate moving average values of the primary side voltage and the secondary side voltage, respectively.

  According to this power transmission state determination device, even when the fluctuation of the system voltage is large, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission.

  In the power transmission state determination device, the first average processing unit and the second average processing unit may calculate a period average value of the primary side voltage and the secondary side voltage, respectively.

  According to this power transmission state determination device, even when the fluctuation of the system voltage is large, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission.

  In this power transmission state determination device, the power transmission state determination processing unit includes a direction of tap switching of the automatic voltage regulator, a sign of the first voltage change and a second voltage change, and the first voltage change. It may be determined whether the distribution system is in the forward power transmission or the reverse power transmission in accordance with the relationship between the voltage change amount and the magnitude of the second voltage change amount.

  According to this power transmission state determination device, even when the fluctuation of the system voltage is large, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission.

  In the power transmission state determination device, the power transmission state determination processing unit includes a sign of the first voltage change and the second voltage change, and the first voltage change and the second voltage change. If the relationship between the distribution system and the automatic voltage regulator does not agree with the relationship assumed from the tap switching direction, the determination as to whether the distribution system is in the forward transmission or reverse transmission state is suspended. You may do.

  According to this power transmission state determination device, erroneous determination of the power transmission state of the automatic voltage regulator can be prevented even when the fluctuation of the system voltage is large.

  In addition, the method for determining the power transmission state of the automatic voltage regulator according to the present invention determines whether the power source is connected to the primary side or the secondary side of the automatic voltage regulator of the on-load tap switching type installed in the distribution system. A power transmission state determination method for detecting and determining whether the distribution system is in a forward power transmission or reverse power transmission state, wherein the primary voltage and the secondary voltage of the automatic voltage regulator are respectively measured. A side voltage measurement stage and a secondary side voltage measurement stage; a first average processing stage and a second average processing stage for calculating average values of the primary side voltage and the secondary side voltage in a predetermined time interval; and The average value of the primary side voltage and the automatic voltage after a predetermined time from when the tap switching of the automatic voltage regulator is performed using the average value of the primary side voltage calculated in the first average processing step. Adjuster tab A first voltage change calculation processing step for calculating a first voltage change amount which is a difference between the average values of the primary side voltage at a predetermined time before the time of switching, and the second average processing step. The average value of the secondary voltage and the tap of the automatic voltage regulator after a predetermined time from when the tap switching of the automatic voltage regulator is performed using the average value of the secondary voltage calculated by A second voltage change calculation processing step of calculating a second voltage change that is a difference between the average values of the secondary side voltages a predetermined time before the switching is performed; and the first voltage change And a power transmission state determination processing step of determining whether the distribution system is in a forward power transmission or reverse power transmission based on the second voltage change.

  According to this power transmission state determination method, the voltage change of the primary side voltage and the secondary side voltage before and after tap switching is calculated based on the average value of the primary voltage and secondary voltage of the automatic voltage regulator in a predetermined time interval. Thus, even when the system voltage changes, it is possible to determine whether the power source such as the distribution substation is connected to the primary side or the secondary side of the automatic voltage regulator.

  In the power transmission state determination method, the first average processing stage and the second average processing stage may calculate moving average values of the primary side voltage and the secondary side voltage, respectively.

  According to this power transmission state determination method, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission even when the fluctuation of the system voltage is large.

  In the power transmission state determination method, the first average processing stage and the second average processing stage may calculate a period average value of the primary side voltage and the secondary side voltage, respectively.

  According to this power transmission state determination method, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission even when the fluctuation of the system voltage is large.

  In the power transmission state determination method, the power transmission state determination processing step includes a tap switching direction of the automatic voltage regulator, a sign of the first voltage change and a second voltage change, and the first voltage change. It may be determined whether the distribution system is in the forward power transmission or the reverse power transmission in accordance with the relationship between the voltage change amount and the magnitude of the second voltage change amount.

  According to this power transmission state determination method, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission even when the fluctuation of the system voltage is large.

  In this power transmission state determination method, the power transmission state determination processing step includes the sign of the first voltage change and the second voltage change, and the first voltage change and the second voltage change. If the relationship between the distribution system and the automatic voltage regulator does not agree with the relationship assumed from the tap switching direction, the determination as to whether the distribution system is in the forward transmission or reverse transmission state is suspended. You may do.

  According to this power transmission state determination method, erroneous determination of the power transmission state of the automatic voltage regulator can be prevented even when the fluctuation of the system voltage is large.

  According to the present invention, by calculating the voltage change of the primary side voltage and the secondary side voltage before and after the tap change based on the average value of the primary voltage and the secondary voltage of the automatic voltage regulator in a predetermined time section. Even when the system voltage changes, the automatic voltage regulator can determine whether the power source such as a distribution substation is connected to the primary side or the secondary side of the automatic voltage regulator. A power transmission state determination device and a power transmission state determination method can be provided.

It is a block diagram of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention. It is a block diagram of the power transmission state determination part which the control part of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention has. It is a block diagram of the process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention performs. It is a graph explaining the N second moving average process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention performs. It is a graph explaining the voltage change part calculation process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention performs. It is a flowchart for demonstrating the process which the control part of the power transmission state determination apparatus of the automatic voltage regulator as the 1st Embodiment of this invention performs. It is a flowchart for demonstrating in detail the process in the flowchart of FIG. It is a graph (the 1) which shows the result of having calculated the 1-second average value of the primary side voltage and the secondary side voltage using the power transmission state determination apparatus of the automatic voltage regulator as the 1st embodiment of the present invention. It is a graph (the 1) which shows the result of having calculated the 5-second moving average value of the primary side voltage and the secondary side voltage using the power transmission state determination apparatus of the automatic voltage regulator as the 1st embodiment of the present invention. . It is a graph (the 2) which shows the result of having calculated the 1-second average value of the primary side voltage and the secondary side voltage using the power transmission state determination apparatus of the automatic voltage regulator as the 1st embodiment of the present invention. It is a graph (the 2) which shows the result of having calculated the 5-second moving average value of the primary side voltage and the secondary side voltage using the power transmission state determination apparatus of the automatic voltage regulator as the 1st embodiment of the present invention. . It is a block diagram of the process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 2nd Embodiment of this invention performs. It is a graph explaining the T second average process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 2nd Embodiment of this invention performs. It is a flowchart for demonstrating in detail the process which the microcomputer of the power transmission state determination apparatus of the automatic voltage regulator as the 2nd Embodiment of this invention performs. It is a graph which shows the example of the aspect of the primary side voltage after the moving average process in the situation where the system voltage is changing, and the secondary side voltage.

  Hereinafter, embodiments of a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator according to the present invention will be described with reference to the drawings.

(First embodiment)
<Power transmission state determination device>
First, the configuration of the power transmission state determination apparatus as the first embodiment of the present invention will be described. As shown in FIG. 1, the power transmission state determination device 10 of this embodiment includes an automatic voltage regulator (SVR) connected to primary distribution lines 1u, 1v, 1w and secondary distribution lines 2u, 2v, 2w. : Step Voltage Regulator) 20 and a control unit 30 for controlling the operation of the SVR 20.

The SVR 20 includes the adjustment transformer 21 having taps t _{u1 to} t _u9 , t _{v1 to} t _v9 , t _{w1 to} t _w9 , and the taps t _{u1 to} t _u9 of the adjustment transformer 21 according to the control signal from the control unit 30. , T _{v1 to} t _v9 , t _{w1 to} t _w9 , the voltage between the load tap switching unit 22 and the U-phase distribution line 1 u and the W-phase distribution line 1 w (hereinafter referred to as “primary side voltage”). The second instrument for detecting the voltage (hereinafter referred to as “secondary voltage”) between the first instrument transformer VT ₁ for detecting the voltage and the u-phase distribution line 2 u and the w-phase distribution line 2 w Transformer VT ₂ , current transformers CT _u1 , CT _w1 for detecting a combined current of the current of distribution line 1 u and the distribution line 1 w whose phase is inverted by 180 degrees, and the distribution whose phase is inverted by 180 degrees A variable that detects the combined current of the current of the wire 2u and the current of the distribution line 2w Mainly comprising a vessel _CT u2, _{CT w2.}

The control unit 30 includes a primary side voltage measurement unit 31 that measures a primary side voltage output from the first instrument transformer VT ₁ and a secondary side voltage output from the second instrument transformer VT _2. Output from the secondary side voltage measuring unit 32 for measuring, the primary side current measuring unit 33 for measuring the combined current on the primary side outputted from the current transformers CT _u1 and CT _w1 , and the current transformers CT _u2 and CT _w2. Tap switching command for performing tap switching of the SVR 20 based on the measurement results of the secondary side current measuring unit 34 that measures the combined current on the secondary side, and the primary side voltage measuring unit 31 and the primary side current measuring unit 33. Based on the measurement results of the primary side voltage adjustment unit 35 that generates V _ta and the secondary side voltage measurement unit 32 and the secondary side current measurement unit 34, a tap switching command V _tb for performing tap switching of the SVR 20 is generated. Secondary-side voltage adjustment unit 36 An operation mode switching unit 37 that selects one of the tap switching commands V _ta and V _tb according to a voltage adjustment mode to be described later and outputs a tap switching signal V _t to the on-load tap switching unit 22 of the SVR 20; Based on the measurement results of the primary side voltage measurement unit 31 and the secondary side voltage measurement unit 32, it is determined whether the power transmission state is forward power transmission or reverse power transmission, and the power transmission state determination signal V _j according to the determination result. Is transmitted to the operation mode switching unit 37.

  Further, the control unit 30 receives the measurement results of the secondary side voltage measurement unit 32 and the secondary side current measurement unit 34 (or the primary side voltage measurement unit 31 and the primary side current measurement unit 33), and reverses the power in the SVR 20. You may provide the reverse flow relay 39 which detects whether the tidal current has arisen. The detection signal of the reverse flow relay 39 is output to the power transmission state determination unit 38.

The primary side voltage adjustment unit 35 generates a tap switching command V _ta so as to keep the primary side voltage at the target voltage in a primary side voltage adjustment mode to be described later. Similarly, the secondary side voltage adjustment unit 36 generates a tap switching command V _tb so as to keep the secondary side voltage at the target voltage in a secondary side voltage adjustment mode to be described later.

The operation mode switching unit 37 responds to the power transmission state determination signal V _j output from the power transmission state determination unit 38 and tap switching commands V _ta , output from the primary side voltage adjustment unit 35 and the secondary side voltage adjustment unit 36. One of V _tb is selected, and the selected tap switching command is output as a tap switching signal V _t to the on-load tap switching unit 22 of the SVR 20 and a power transmission state determination unit 38 to be described later.

Load tap changeover unit 22, voltage outputted by switching the taps of the regulating transformer 21 as a trigger tap switching signal V _t primary voltage or secondary side voltage from the operation mode switching unit 37 so as to maintain the target voltage Adjustments are made.

<Power transmission state determination unit>
As shown in FIG. 2, the power transmission state determination unit 38 includes voltage input units 41 and 42, A / D conversion units 43 and 44, a microcomputer 45, and a control signal output unit 46.

  The voltage input units 41 and 42 perform level conversion on each of the primary side voltage output from the primary side voltage measurement unit 31 and the secondary side voltage output from the secondary side voltage measurement unit 32 for filtering. It has become.

  The A / D conversion unit 43 performs analog / digital conversion of an instantaneous value at a predetermined sampling period on an analog signal that gives a primary side voltage input from the primary side voltage measurement unit 31 via the voltage input unit 41. The obtained digital signal is output as primary side voltage data.

  Similarly, the A / D conversion unit 44 converts an analog signal that gives the secondary side voltage input from the secondary side voltage measurement unit 32 via the voltage input unit 42 into a digital signal, and converts the digital signal to the secondary signal. It is designed to output as side voltage data.

The microcomputer 45 includes a digital signal output from the A / D converter 43, and the tap switching signal V _t outputted from the operation mode switching unit 37, the backward flow detection signal outputted from the backflow relay 39 inputs After performing processing to be described later based on these signals, a control signal (power transmission state determination signal V _j ) is output to the operation mode switching unit 37 via the control signal output unit 46. It has become.

<Microcomputer processing>
As shown in FIG. 3, the microcomputer 45 executes a predetermined program to thereby execute first and second effective value conversion processing units 51 and 52, first and second average processing units 53 and 54, and The first and second voltage change processing units 55 and 56 and the power transmission state determination processing unit 57 are configured in software.

  The first effective value conversion processing unit 51 performs effective value conversion on the primary side voltage data output from the primary side voltage measurement unit 31 via the A / D conversion unit 43. Similarly, the second effective value conversion processing unit 52 performs effective value conversion on the secondary side voltage data output from the secondary side voltage measurement unit 32 via the A / D conversion unit 44. ing.

  The first average processing unit 53 is configured to calculate an average value in a predetermined time section of the primary side voltage data subjected to the effective value conversion by the first effective value conversion processing unit 51. Further, the second average processing unit 54 calculates an average value in a predetermined time section of the secondary side voltage data subjected to the effective value conversion by the second effective value conversion processing unit 52.

  The first voltage change calculation processing unit 55 uses the average value of the primary side voltage data obtained by the first average processing unit 53 to calculate the voltage change before and after the tap switching of the SVR 20. Yes. Similarly, the second voltage change calculation processing unit 56 uses the average value of the secondary side voltage data obtained by the second average processing unit 54 to calculate the voltage change before and after the tap switching of the SVR 20. It is like that.

  The power transmission state determination processing unit 57 determines whether the power transmission state is forward power transmission or reverse power transmission based on the voltage change calculated by the first and second voltage change calculation processing units 55 and 56, respectively. It is supposed to be.

<Average processing and voltage change calculation processing>
Next, the contents of processing executed by the first and second average processing units 53 and 54 and the first and second voltage change calculation processing units 55 and 56 will be described. Conventionally, when obtaining the voltage change before and after the tap switching, the 1-second average value of the voltage data has been used. However, since the system voltage fluctuates in units of seconds, the configuration using the 1-second average value of voltage data as in the prior art has a problem that the power transmission state is easily misjudged due to the fluctuation of the system voltage.

  Based on this, in the present embodiment, the first and second average processing units 53 and 54 always perform the first-second average value of the primary-side voltage data and the secondary-side voltage data for N-second moving average processing, The second voltage change calculation processing units 55 and 56 use the N-second moving average value output from the first and second average processing units 53 and 54 to obtain the voltage change before and after the tap switching. Thereby, it becomes possible to reduce the influence of fluctuations in the system voltage. Here, it is assumed that N seconds is about 5 seconds, for example.

The first average processing unit 53 includes a 1-second average processing unit 53a and an N-second moving average processing unit 53b. The one-second average processing unit 53a calculates a one-second average value V 1 — _n that is an average value of data for one second of the primary side voltage data subjected to the effective value conversion by the first effective value conversion processing unit 51. ing.

As shown in FIG. 4 and _Equation 1, the N-second moving average processing unit 53b calculates the N-second moving average value V _{1a_n} of the 1-second average value V 1 — n calculated by the 1-second average processing unit 53a.

Similarly, the second average processing unit 54 includes a 1-second average processing unit 54a and an N-second moving average processing unit 54b. The 1-second average processing unit 54a calculates a 1-second average value V 2 — _n that is an average value of data for one second of the secondary-side voltage data that has _undergone effective value conversion by the second effective value conversion processing unit 52. It has become. The N-second moving average processing unit 54b calculates the N-second moving average value V _{2a_n} of the 1-second average value V _{2_n} calculated by the 1-second average processing unit 54a according to _Equation 2.

As shown in FIG. 5 and _Equation 3, the first voltage change calculation processing unit 55 uses the N-second moving average values V _{1a_t1} and V _{1a_t2} output from the first average processing unit 53 before and after the tap switching. The voltage change ΔV ₁ on the primary side is calculated. Here, V _{1a_t1} is an N-second moving average value on the primary side t ₁ second before the time when the tap is switched, and V _{1a_t2} is N on the primary side t ₂ seconds after the time when the tap is switched. Second moving average value.

Similarly, the second voltage change calculation processing unit 56 uses the N-second moving average values V _{2a_t1} and V _{2a_t2} output from the second average processing unit 54 to change the voltage change on the secondary side before and after the tap switching. ΔV ₂ is calculated according to Equation 4. Here, V _{2a_t1} is an N-second moving average value on the secondary side t ₁ second before the time at which the tap switching is performed, and V _{2a_t2} is a secondary side t ₂ seconds after the time at which the tap switching is performed. The N-second moving average value.

<Power transmission state judgment method>
Next, the power transmission state determination method of this embodiment will be described. FIG. 6 is a flowchart of a power transmission state determination program executed by the control unit 30 of the power transmission state determination device 10.

  First, in step S <b> 1, the control unit 30 detects the primary side voltage of the SVR 20 with the primary side voltage measurement unit 31 and detects the secondary side voltage of the SVR 20 with the secondary side voltage measurement unit 32.

  Next, in step S <b> 2, the control unit 30 performs an effective operation on the primary side voltage data output from the primary side voltage measurement unit 31 via the A / D conversion unit 43 by the first effective value conversion processing unit 51. Perform value conversion. Similarly, the control unit 30 performs effective value conversion on the primary side voltage data output from the secondary side voltage measurement unit 32 via the A / D conversion unit 44 by the second effective value conversion processing unit 52. Do.

Next, in step S _<b> 3, the control unit 30 calculates the 1-second average value V 1 — _n of the primary side voltage data subjected to the effective value conversion by the first effective value conversion processing unit 51 by the 1-second average processing unit 53 a. Similarly, the control unit 30 calculates the 1-second average value V 2 — _n of the secondary side voltage data subjected to the effective value conversion by the second effective value conversion processing unit 52 by the 1-second average processing unit 54 a.

Next, in step S4, the control unit 30, the N seconds moving average processing unit 53b, calculates a N seconds moving average value _{V 1A_n} of 1 second average value _{V 1_n} calculated by 1 sec averaging processor 53a. Similarly, the control unit 30 calculates the N-second moving average value V _{2a_n} of the 1-second average value V ₂ — n calculated by the 1-second average processing unit 54 a by the N-second moving average processing unit 54 _b .

  In addition, the process from step S1 to step S4 shall always be performed irrespective of the process of the following step S5.

Next, in step S5, the control unit 30 determines the power transmission state determination processing unit 57 based on the voltage changes ΔV ₁ and ΔV ₂ calculated by the first and second voltage change calculation processing units 55 and 56, respectively. To determine whether the power transmission state is forward power transmission or reverse power transmission.

<Process of step S5>
Next, details of the processing in step S5 in the flowchart of FIG. 6 will be described. FIG. 7 is a flowchart of processing executed by the microcomputer 45 of the power transmission state determination unit 38 included in the control unit 30.

First, in step S11, the microcomputer 45 determines whether the operation mode switching unit 37 the tap switching signal V _t indicating that the tap switching SVR20 is performed occurs. When the operation mode switching unit 37 has generated the tap switching signal V _t is the microcomputer 45 executes the process of step S12. On the other hand, when the operation mode switching unit 37 does not generate the tap switching signal V _t is the microcomputer 45 executes the process of step S11 again.

Next, in step S12, the microcomputer 45 performs tap switching using the N-second moving average values V _{1a_t1} and V _{1a_t2} output from the first average processing unit 53 by the first voltage change calculation processing unit 55. The voltage change ΔV ₁ on the primary side before and after is calculated. Similarly, the microcomputer 45 uses the N-second moving average values V _{2a_t1} and V _{2a_t2} output from the second average processing unit 54 by the second voltage change calculation processing unit 56 to _perform secondary switching before and after tap switching. Side voltage change ΔV ₂ is calculated.

Next, in step S13, the microcomputer 45, the absolute value of the voltage variation [Delta] V ₁ of the primary-side | [Delta] V 1 _| secondary side absolute value of the voltage variation [Delta] V ₂ of | [Delta] V 2 _| or less or not than Determine. When the absolute value | ΔV ₁ | of the primary side voltage change is smaller than the absolute value | ΔV ₂ | of the secondary side voltage change, that is, in the case of forward power transmission, the microcomputer 45 performs step S14. Execute the process. On the other hand, when the absolute value | ΔV ₁ | of the primary side voltage change is not smaller than the absolute value | ΔV ₂ | of the secondary side voltage change, that is, when the forward power transmission is not performed, the microcomputer 45 The process of step S15 is executed.

Next, in step S14, the microcomputer 45 outputs the power transmission state determination signal V _j to the operation mode switching unit 37 sets the operation mode of SVR20 the secondary side voltage regulation mode. As a result, the tap switching command V _tb generated by the secondary side voltage adjusting unit 36 of the SVR 20 is output to the on-load tap switching unit 22. The microcomputer 45 executes the process of step S11 again after setting the operation mode of the SVR 20 to the secondary side voltage adjustment mode in step S14.

Next, in step S15, the microcomputer 45 determines whether or not the absolute value | ΔV ₁ | of the primary side voltage change is larger than the absolute value | ΔV ₂ | of the secondary side voltage change. When the absolute value | ΔV ₁ | of the primary side voltage change is larger than the absolute value | ΔV ₂ | of the secondary side voltage change, that is, in the case of reverse power transmission, the microcomputer 45 performs step S16. Execute the process. On the other hand, if the absolute value | ΔV ₁ | of the primary side voltage change is not larger than the absolute value | ΔV ₂ | of the secondary side voltage change, that is, if it is not reverse power transmission, the microcomputer 45 Then, the current operation mode is maintained and the process of step S11 is executed again.

Next, in step S16, the microcomputer 45 outputs the power transmission state determination signal V _j to the operation mode switching unit 37 sets the operation mode of SVR20 the primary voltage regulating mode. As a result, the tap switching command V _ta generated by the primary side voltage adjusting unit 35 of the SVR 20 is output to the on-load tap switching unit 22. The microcomputer 45 executes the process of step S11 again after setting the operation mode of the SVR 20 to the primary side voltage adjustment mode in step S16.

  Note that if the SVR 20 includes the reverse flow relay 39 and the distribution system is in a distribution system operation in which the distribution system is almost always in the forward transmission state, the reverse flow has occurred in the SVR 20 before the process of step S11 in the flowchart of FIG. A process for determining whether or not the reverse flow relay 39 has generated a reverse flow detection signal indicating () may be added (step S0). Thereby, in the distribution system operation in which the distribution system is almost always in the forward power transmission state, it is possible to reduce the influence of the erroneous determination.

  Specifically, when the reverse flow relay 39 generates a reverse flow detection signal, the microcomputer 45 executes the process of step S11. On the other hand, when the reverse flow relay 39 does not generate the reverse flow detection signal, that is, in the case of a forward flow, the microcomputer 45 executes the process of step S11 again.

<Measurement results>
Next, measurement results using the power transmission state determination device 10 of the present embodiment will be described with reference to FIGS. FIGS. 8-11 has shown the aspect of the voltage of the primary side and secondary side of SVR20 when tap switching is performed in the condition where the system voltage is fluctuating. The measurement conditions are as shown below.

・ Use test data: 2 types (test data I, test data II)
・ Power supply position: Secondary side of SVR20 (reverse power transmission)
T ₁ = t ₂ = 5 seconds Tap switching direction: primary side step-up (FIGS. 8 and 9), primary side step-down (FIGS. 10 and 11)
Note that the primary side boosting is realized, for example, by increasing the number of turns of the primary winding of the SVR 20, and the primary side step-down is realized, for example, by reducing the number of turns of the primary winding of the SVR 20.

  FIG. 8 shows the 1-second average value of the primary side voltage of the SVR 20 (thick solid line) when only the 1-second average processing is performed on the test data I in the first and second average processing units 53 and 54. 4 is a graph showing the 1-second average value (thin solid line) of the secondary side voltage of SVR20.

In this example, the tap switching time t ₀ is 10:24:19, the pre-tap switching time (t ₀ -t ₁ ) is 10:24:14, and the post-tap switching time (t ₀ + t ₂ ) is 10:24:24. It is.

In the example of FIG. 8, the 1-second average value V _{1_t1 of} the primary side voltage at the time (t ₀ -t ₁ ) before tap switching, and the 1-second average value V of the primary side voltage at the time (t ₀ + t ₂ ) after tap switching. _{1_T2,} tap changer previous time _(t 0 -t ₁₎ 1 second averages _{V 2_T1} of the secondary-side voltage at the tap after switching time _(t 0 + t ₂₎ of the secondary-side voltage at the second average value _{V 2_T2,} primary The voltage change ΔV ₁ on the side and the voltage change ΔV ₂ on the secondary side are as shown in the upper part of Table 2, respectively. That is, the voltage before and after the tap switching changes from the primary side to the positive side and from the secondary side to the negative side, and the magnitude relationship between the absolute values is | ΔV ₁ | <| ΔV ₂ |.

Here, ΔV ₁ and ΔV ₂ are given by Equation 5.

Therefore, in the example of FIG. 8, the absolute value | ΔV ₁ | of the primary side voltage change is smaller than the absolute value | ΔV ₂ | of the secondary side voltage change. The state is erroneously determined as forward power transmission. This is because the fluctuation of the system voltage is larger than the voltage change due to tap switching.

  FIG. 9 shows that the primary side voltage of the SVR 20 is moved for 5 seconds when the first and second average processing units 53 and 54 perform the 5-second moving average process on the 1-second average value of the test data I. It is a graph which shows a 5-second moving average value (thin solid line) of an average value (thick solid line) and the secondary side voltage of SVR20.

In this example, similarly to the example shown in FIG. 8, the tap switching time t ₀ is 10:24:19, the tap switching time (t ₀ -t ₁ ) is 10:24:14, and the tap switching time (t ₀ + _{t 2)} is 10:24:24.

In the example of FIG. 9, the 5-second moving average value V _{1a_t1 of the} primary side voltage at the time (t ₀ -t ₁ ) before tap switching, and the 5-second moving average of the primary side voltage at the time (t ₀ + t ₂ ) after tap switching. the value _{V 1a_t2,} 5 seconds moving average value of the secondary-side voltage at the tap changeover previous time _(t 0 -t ₁₎ of the secondary side voltage of 5 seconds moving average value _{V 2a_t1,} tap after switching time _(t 0 + t ₂₎ V _{2a — t 2} , primary-side voltage change ΔV ₁ , and secondary-side voltage change ΔV ₂ are as shown in the lower part of Table 2. That is, the voltage before and after the tap switching changes from the primary side to the positive side and from the secondary side to the negative side, and the magnitude relationship between the absolute values is | ΔV ₁ |> | ΔV ₂ |.

Therefore, in the example of FIG. 9, the absolute value | ΔV ₁ | of the primary side voltage change is larger than the absolute value | ΔV ₂ | of the secondary side voltage change. The state is correctly determined as reverse power transmission.

  FIG. 10 shows the one-second average value (thick solid line) of the primary side voltage of the SVR 20 when only the one-second average processing is performed on the test data II in the first and second average processing units 53 and 54. 4 is a graph showing another example of the 1-second average value (thin solid line) of the secondary side voltage of SVR20.

In this example, the tap switching time t ₀ is 11:02:11, the pre-tap switching time (t ₀ -t ₁ ) is 11:02:06, and the post-tap switching time (t ₀ + t ₂ ) is 11:02:16. It is.

In the example of FIG. 10, the 1-second average value V _{1_t1 of} the primary side voltage at the time (t ₀ -t ₁ ) before the tap switching, and the 1-second average value V 1 of the primary side voltage at the time (t ₀ + t ₂ ) after the tap switching. _{1_T2,} tap changer previous time _(t 0 -t ₁₎ 1 second averages _{V 2_T1} of the secondary-side voltage at the tap after switching time _(t 0 + t ₂₎ of the secondary-side voltage at the second average value _{V 2_T2,} primary The voltage change ΔV ₁ on the side and the voltage change ΔV ₂ on the secondary side are as shown in the upper part of Table 3, respectively. That is, the voltage before and after the tap switching changes in the positive direction on both the primary side and the secondary side, and the magnitude relationship between the absolute values is | ΔV ₁ | <| ΔV ₂ |.

Therefore, in the example of FIG. 10, the absolute value | ΔV ₁ | of the primary side voltage change is smaller than the absolute value | ΔV ₂ | of the secondary side voltage change. The state is erroneously determined as forward power transmission. This is due to the fact that the fluctuation of the system voltage is larger than the voltage change due to tap switching, as in the example of FIG.

  FIG. 11 shows that the primary side voltage of the SVR 20 is moved for 5 seconds when the first and second average processing units 53 and 54 perform the 5-second moving average process on the 1-second average value of the test data II. It is a graph which shows a 5-second moving average value (thin solid line) of an average value (thick solid line) and the secondary side voltage of SVR20.

In this example, similarly to the example shown in FIG. 10, the tap switching time t ₀ is 11:02:11, the tap switching time (t ₀ -t ₁ ) is 11:02:06, and the tap switching time (t ₀ + _{t 2)} is 11:02:16.

In the example of FIG. 11, the 5-second moving average value V _{1a_t1 of the} primary side voltage at the time (t ₀ -t ₁ ) before the tap switching, and the 5-second moving average of the primary voltage at the time (t ₀ + t ₂ ) after the tap switching. the value _{V 1a_t2,} 5 seconds moving average value of the secondary-side voltage at the tap changeover previous time _(t 0 -t ₁₎ of the secondary side voltage of 5 seconds moving average value _{V 2a_t1,} tap after switching time _(t 0 + t ₂₎ V _{2a — t 2} , primary side voltage change ΔV ₁ , and secondary side voltage change ΔV ₂ are as shown in the lower part of Table 3, respectively. That is, the voltage before and after the tap switching changes from the primary side to the negative side and from the secondary side to the positive side, and the magnitude relationship between the absolute values is | ΔV ₁ |> | ΔV ₂ |.

Therefore, in the example of FIG. 11, the absolute value | ΔV ₁ | of the primary side voltage change is larger than the absolute value | ΔV ₂ | of the secondary side voltage change. The state is correctly determined as reverse power transmission.

  From the above results, even when the fluctuation of the system voltage is large and erroneous determination occurs in the determination of the power transmission state based on the 1-second average value of the conventional voltage data, the power transmission state determination device and the power transmission state of the present embodiment The determination method can improve the determination accuracy of the power transmission state by determining the power transmission state based on the N-second moving average value of the primary side voltage data and the secondary side voltage data.

  In addition, when the correct determination is obtained in the determination of the power transmission state based on the 1-second average value of the primary side voltage data and the secondary side voltage data, the 5-second moving average of the primary side voltage data and the secondary side voltage data is obtained. It has been confirmed that a correct determination can be obtained in the determination of the power transmission state based on the value.

In the above description, both t ₁ and t ₂ are 5 seconds. However, the values of t ₁ and t ₂ are not limited to this. For example, the value of t ₁ is 1 second and the value of t ₂ is 2 to 5 It is good also as a value of the range of a second or 5-10 seconds. However, the value of N seconds moving average N is equal to the value of t _2. Thus, by shortening the time (t ₁ + t ₂ ) from the time before tap switching (t ₀ -t ₁ ) to the time after tap switching (t ₀ + t ₂ ), or by increasing the value of N The influence of fluctuations in the system voltage can be further reduced.

  As described above, according to the present embodiment, the voltage of the primary side voltage and the secondary side voltage before and after the tap change based on the average value of the primary voltage and the secondary voltage of the automatic voltage regulator in the predetermined time interval. By calculating the amount of change, even if the system voltage changes before and after tap switching of the automatic voltage regulator, a power source such as a distribution substation is installed on either the primary side or the secondary side of the automatic voltage regulator. It is possible to provide a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator that can determine whether or not they are connected.

(Second Embodiment)
Next, a power transmission state determination device and a power transmission state determination method as a second embodiment of the present invention will be described with reference to the drawings. Note that the description of the same configuration and operation as in the first embodiment will be omitted as appropriate.

  In the present embodiment, the contents of processing executed by the first and second average processing units 53 and 54 and the first and second voltage change calculation processing units 55 and 56 will be described.

  The first and second average processing units 53 and 54 calculate the 1-second average value and the N-second moving average value of the primary side voltage data and the secondary side voltage data in the first embodiment. In the present embodiment, a T-second average value as a period average value of the primary side voltage data and the secondary side voltage data is calculated. Here, T seconds are assumed to be about 3 to 10 seconds, for example.

That is, as shown in FIG. 12, the first average processing units 53 and 54 include T second average processing units 53c and 54c, respectively. The T-second average processing unit 53c is the primary value whose effective value has been converted by the first effective value conversion processing unit 51 in the vicinity of the time before tap switching (t ₀ -t ₁ ) and the time after tap switching (t ₀ + t ₂ ). T-second average values V _{1T_t1} and V _{1T_t2} , which are average values of data for T seconds of the side voltage data, are calculated.

Similarly, the T-second average processing unit 54c performs the effective value conversion by the second effective value conversion processing unit 52 in the vicinity of the time before tap switching (t ₀ -t ₁ ) and the time after tap switching (t ₀ + t ₂ ). T-second average values V _{2T_t1} and V _{2T_t2} , which are average values of data for T seconds of the secondary voltage data _{thus obtained} , are calculated.

As shown in FIG. 13 (a), the T-second average processing unit 53c starts from a time t ₁ before tap switching (in the example of FIG. 13, the tap switching time is t ₀ = 0) and a time t ₂ after tap switching. An average value of T seconds of voltage data of the past T seconds may be calculated.

Alternatively, T seconds averaging unit 53c calculates the T seconds average value of the voltage data for the past T seconds from the tap changeover previous time t ₁ as shown in FIG. 13 (b), the future from the tap after switching time t ₂ The T-second average value of the T-second voltage data may be calculated. The same applies to the T second average processing unit 54c.

Note that the time before tap switching (t ₀ -t ₁ ) and the time after tap switching (t ₀ + t ₂ ) may be times less than 5 seconds before and after tap switching time t ₀ . However, when the T-second average value is calculated using the voltage data of the past T seconds from the time after the tap switching (t ₀ + t ₂ ) as shown in FIG. T ₂ −t ₀ needs to be larger than T so as not to reach the time before the switching time t ₀ . That is, the shorter the time from the tap changeover time t ₀ to the tap after switching time (t 0 _{+ t 2)} is limited.

(Third embodiment)
Next, a power transmission state determination device and a power transmission state determination method as a third embodiment of the present invention will be described with reference to the drawings. Note that description of the configuration and operation similar to those of the first and second embodiments will be omitted as appropriate.

  FIG. 14 is a flowchart of the process executed by the microcomputer 45 in the power transmission state determination apparatus 10 of the present embodiment, and shows details of the process in step S5 of the flowchart of FIG. Note that the processes in steps S21, S22, S24, and S25 are the same as the processes in steps S11, S12, S14, and S16 in the flowchart of FIG. 7, and thus description of these processes is omitted.

Memory of the microcomputer 45 (not shown), the direction of the tap changer of SVR20, the voltage change of the primary content [Delta] V ₁ and the secondary-side voltage variation [Delta] V ₂ code, the voltage variation [Delta] V ₁ of the primary side And a table indicating the correspondence between the magnitude of the voltage change ΔV ₂ on the secondary side and the determination result of the power transmission state of the SVR 20. Table 4 shows the contents of this table.

  In step S23, the microcomputer 45 performs a process of determining whether the SVR 20 is in the forward power transmission or the reverse power transmission based on the table shown in Table 4.

In Table 4, patterns 1, 2, 7, 8, 11, 12, 14, ₁₅ and pattern 4 (in the case of | ΔV ₁ | ≦ | ΔV ₂ |) and pattern 6 (| ΔV ₁ | = | ΔV ₂ ), Pattern 9 (when | ΔV ₁ | ≧ | ΔV ₂ |), pattern 13 (when | ΔV ₁ | ≧ | ΔV ₂ |), and pattern 16 (| ΔV ₁ | = | ΔV ₂ |). If), the pattern _{18 (| ΔV 1 | ≦ |} ΔV 2 | case) has a primary side of the voltage change amount [Delta] V ₁ and the secondary side of the voltage variation [Delta] V ₂ code, the primary side of the voltage variation [Delta] V ₁ This corresponds to a case (determination pending) in which the relationship between the voltage change ΔV ₂ on the secondary side and the magnitude of the voltage change ΔV ₂ on the secondary side does not match the relationship assumed from the tap switching direction of the SVR 20.

  If the fluctuation of the system voltage can be completely removed by some means, it is considered that the above-described determination suspension pattern does not occur. However, if it is not possible to completely remove the fluctuation even after moving average processing, or if there is an error due to a measurement error or the like in the obtained voltage change, the pending determination shown in Table 4 is used. A pattern is expected to occur.

Therefore, in step S23, and the primary side of the voltage change amount [Delta] V ₁ and the secondary side of the voltage variation [Delta] V ₂ code, and the magnitude of the change in the voltage variation [Delta] V ₁ and the secondary side of the primary side partial [Delta] V ₂ Is not consistent with the relationship assumed from the tap switching direction of the SVR 20, a process of holding the determination as to whether the SVR 20 is in the forward power transmission or the reverse power transmission is performed. As a result, erroneous determination can be reduced as much as possible, and determination accuracy can be improved.

<Determination of power transmission status>
FIG. 15A and FIG. 15B show examples of aspects of the primary voltage and the secondary voltage of the SVR 20 after the moving average process in a situation where the system voltage is fluctuating. In the example of FIGS. 15A and 15B, tap switching is performed in a direction in which the number of turns of the primary winding of the SVR 20 decreases in a forward power transmission state in which a power source is connected to the primary side of the SVR 20. . However, the aspect of system voltage fluctuation is different between the example of FIG. 15A and the example of FIG. 15B.

In the case of the example in FIG. 15A, the voltage change before and after the tap switching changes in the positive direction on both the primary side and the secondary side, and the magnitude relationship between the absolute values is | ΔV ₁ | <| ΔV ₂ | It is. This corresponds to | ΔV ₁ | <| ΔV ₂ | of the pattern 9 shown in Table 4. At this time, the microcomputer 45 determines that the power transmission state is a forward power transmission state, and executes the process of step S24.

In the case of the example of FIG. 15B, the voltage change before and after the tap switching changes from the primary side to the negative side and from the secondary side to the positive side. The magnitude relationship between the absolute values is | ΔV ₁ | <| ΔV ₂ |. This corresponds to | ΔV ₁ | <| ΔV ₂ | of the pattern 6 shown in Table 4.

However, since the difference between | ΔV ₁ | and | ΔV ₂ | is small, in some cases, | ΔV ₁ | = | ΔV ₂ | ΔV ₁ and ΔV ₂ can be calculated incorrectly. This corresponds to | ΔV ₁ | = | ΔV ₂ | of the pattern 6 shown in Table 4.

Therefore, in the example of FIG. 15B, when | ΔV ₁ | <| ΔV ₂ |, the microcomputer 45 determines that the power transmission state is a forward power transmission state, and executes the process of step S24. . On the other hand, if | ΔV ₁ | = | ΔV ₂ |, the microcomputer 45 suspends the determination of the power transmission state, maintains the current operation mode, and executes the process of step S21 again.

  As another example, for example, when the power is connected to the primary side of the SVR 20 and the tap is switched to the side where the number of turns of the primary winding of the SVR 20 is reduced, the system voltage is If it does not change, the primary voltage of the SVR 20 hardly changes, and the secondary voltage of the SVR 20 increases. This corresponds to the pattern 3 shown in Table 4. At this time, the microcomputer 45 determines that the power transmission state is a forward power transmission state, and executes the process of step S24.

  On the other hand, when tap switching is performed on the side where the number of turns of the primary winding of the SVR 20 is increased in a reverse power transmission state where the power source is connected to the secondary side of the SVR 20, if the system voltage does not change, The secondary voltage of the SVR 20 hardly changes and the primary voltage of the SVR 20 increases. This corresponds to the pattern 17 shown in Table 4. At this time, the microcomputer 45 determines that the power transmission state is a reverse power transmission state, and executes the process of step S25.

  On the other hand, if neither the primary side voltage nor the secondary side voltage of the SVR 20 changes substantially despite the tap switching, there is a high possibility that the system voltage has changed. This corresponds to the patterns 2 and 11 shown in Table 4. At this time, the microcomputer 45 puts the determination of the power transmission state on hold, maintains the current operation mode, and executes the process of step S21 again.

  In addition, when tap switching is performed on the side where the number of turns of the primary winding of the SVR 20 is reduced in the state of forward power transmission, the primary side voltage of the SVR 20 hardly changes and the secondary side voltage of the SVR 20 decreases. However, there is a high possibility that the system voltage has changed. This corresponds to Pattern 1 shown in Table 4. Also at this time, the microcomputer 45 puts the determination of the power transmission state on hold, maintains the current operation mode, and executes the process of step S21 again.

  On the other hand, when tap switching is performed to the side where the number of turns of the primary winding of the SVR 20 is increased in the state of reverse power transmission, the secondary side voltage of the SVR 20 hardly changes and the primary side voltage of the SVR 20 decreases. However, there is a high possibility that the system voltage has changed. This corresponds to the pattern 14 shown in Table 4. Also at this time, the microcomputer 45 puts the determination of the power transmission state on hold, maintains the current operation mode, and executes the process of step S21 again.

The measurement result of FIG. 9 (after the moving average process) shown in the first embodiment corresponds to “ΔV ₁ > ΔV ₂ ” of the pattern 16 (the power supply position is the secondary side of the SVR 20). 11 corresponds to “ΔV ₁ > ΔV ₂ ” of the pattern 6 (the power supply position is the secondary side of the SVR 20).

  As in the first embodiment, if the SVR 20 includes the reverse flow relay 39 and the distribution system is in a distribution system operation in which the distribution system is almost always in the forward power transmission state, the process before step S21 in the flowchart of FIG. 14 is performed. A process for determining whether or not the reverse flow relay 39 has generated a reverse flow detection signal indicating that a reverse flow has occurred in the SVR 20 may be added.

  As described above, according to the present embodiment, even when the fluctuation of the system voltage is large, it is possible to accurately determine whether the automatic voltage regulator is in the forward power transmission or the reverse power transmission. It is possible to provide a power transmission state determination device and a power transmission state determination method for an automatic voltage regulator that can prevent erroneous determination of the power transmission state.

10 Power transmission state determination device 20 SVR
DESCRIPTION OF SYMBOLS 21 Adjustment transformer 22 Load tap switching part 30 Control part 31 Primary side voltage measurement part 32 Secondary side voltage measurement part 33 Primary side current measurement part 34 Secondary side current measurement part 35 Primary side voltage adjustment part 36 Secondary side voltage Adjustment unit 37 Operation mode switching unit 38 Power transmission state determination unit 39 Backflow relay 41, 42 Voltage input unit 43, 44 A / D conversion unit 45 Microcomputer 46 Control signal output unit 51 First effective value conversion processing unit 52 Second Effective value conversion processing unit 53 First average processing unit 54 Second average processing unit 53a, 54a 1 second average processing unit 53b, 54b N second moving average processing unit 53c, 54c T second average processing unit 55 First voltage change min calculator 56 second voltage variation calculation processing unit 57 transmission state determination processing unit 1u, 1v, 1w distribution lines 2u, 2v, 2w distribution line CT _{u1, CT w1} CT _{u2, CT w2} current transformer VT ₁ first voltage transformer VT ₂ second potential transformer

Claims (10)

Detects whether the power supply is connected to the primary side or the secondary side of the automatic voltage regulator of the tap switching type on-load installed in the distribution system, and whether the distribution system is in the forward transmission or reverse transmission state A power transmission state determination device for determining whether or not
A primary side voltage measuring unit and a secondary side voltage measuring unit for measuring a primary side voltage and a secondary side voltage of the automatic voltage regulator, respectively;
A first average processing unit and a second average processing unit that calculate average values of the primary side voltage and the secondary side voltage in a predetermined time interval, respectively;
Using the average value of the primary voltage calculated by the first average processing unit, the average value of the primary voltage and the automatic value after a predetermined time from when the tap switching of the automatic voltage regulator is performed. A first voltage change calculation processing unit that calculates a first voltage change that is a difference between the average values of the primary side voltages at a predetermined time before the voltage regulator tap is switched;
Using the average value of the secondary side voltage calculated by the second average processing unit, the average value of the secondary side voltage after a predetermined time from when the tap switching of the automatic voltage regulator is performed, and A second voltage change calculation processing unit that calculates a second voltage change that is a difference in average value of the secondary side voltage a predetermined time before the automatic voltage regulator tap is switched;
A power transmission state determination processing unit that determines whether the distribution system is in a forward power transmission or a reverse power transmission based on the first voltage change and the second voltage change; A power transmission state determination device.   The power transmission state determination device according to claim 1, wherein the first average processing unit and the second average processing unit calculate moving average values of the primary side voltage and the secondary side voltage, respectively.   The power transmission state determination device according to claim 1, wherein the first average processing unit and the second average processing unit calculate average values of the primary side voltage and the secondary side voltage, respectively.   The power transmission state determination processing unit includes a tap switching direction of the automatic voltage regulator, a sign of the first voltage change and the second voltage change, and the first voltage change and the first voltage change. 4. The method according to claim 1, further comprising: determining whether the power distribution system is in a forward power transmission or a reverse power transmission according to a relationship with a magnitude of a voltage change amount of 2. The power transmission state determination device according to claim 1.   The power transmission state determination processing unit has a relationship between the sign of the first voltage change and the second voltage change, and the magnitude of the first voltage change and the second voltage change. The determination as to whether the distribution system is in a forward power transmission or a reverse power transmission is suspended if the relationship does not coincide with a relationship assumed from the tap switching direction of the automatic voltage regulator. Item 5. The power transmission state determination device according to Item 4. Detects whether the power supply is connected to the primary side or the secondary side of the automatic voltage regulator of the tap switching type on-load installed in the distribution system, and whether the distribution system is in the forward transmission or reverse transmission state A power transmission state determination method for determining whether or not
A primary side voltage measurement stage and a secondary side voltage measurement stage for measuring a primary side voltage and a secondary side voltage of the automatic voltage regulator, respectively;
A first average processing stage and a second average processing stage for calculating average values of the primary side voltage and the secondary side voltage in a predetermined time interval, respectively;
Using the average value of the primary side voltage calculated in the first average processing step, the average value of the primary side voltage and the automatic value after a predetermined time from the time when the tap switching of the automatic voltage regulator is performed. A first voltage change calculation processing step of calculating a first voltage change that is a difference between the average values of the primary side voltages at a predetermined time before the voltage regulator tap is switched;
Using the average value of the secondary side voltage calculated by the second average processing step, the average value of the secondary side voltage after a predetermined time from when the tap switching of the automatic voltage regulator is performed, and A second voltage change calculation processing step of calculating a second voltage change that is a difference between the average values of the secondary side voltages at a predetermined time before the automatic voltage regulator is switched;
A power transmission state determination processing step of determining whether the distribution system is in a forward power transmission or a reverse power transmission based on the first voltage change and the second voltage change. Power transmission state determination method.   The power transmission state determination method according to claim 6, wherein the first average processing stage and the second average processing stage respectively calculate moving average values of the primary side voltage and the secondary side voltage.   The power transmission state determination method according to claim 6, wherein the first average processing stage and the second average processing stage calculate period average values of the primary side voltage and the secondary side voltage, respectively.   The power transmission state determination processing step includes a direction of tap switching of the automatic voltage regulator, a sign of the first voltage change and the second voltage change, the first voltage change and the first voltage change. 9. The method according to claim 6, further comprising: determining whether the distribution system is in a forward transmission state or a reverse transmission state according to a relationship with a magnitude of a voltage change amount of 2. The power transmission state determination method described in 1.   In the power transmission state determination processing step, the relationship between the sign of the first voltage change and the second voltage change, and the magnitude of the first voltage change and the second voltage change, The determination as to whether the distribution system is in a forward power transmission or a reverse power transmission is suspended if the relationship does not coincide with a relationship assumed from the tap switching direction of the automatic voltage regulator. Item 10. The power transmission state determination method according to Item 9.

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