VOLTAGE REGULATOR SELECTION DEVICE, VOLTAGE REGULATOR SELECTION PROGRAM, AND VOLTAGE REGULATOR SELECTION METHOD

Abstract

A device for selecting a voltage regulator for power saving at an electricity consumer having electrical equipment connected to a low-voltage distribution system includes a power saving judgment index data generating unit that generates power saving judgment index data serving as a judgment index when selecting a voltage regulator, based on historical data of power and voltage or alternative data at a candidate installation location of the voltage regulator on the low-voltage distribution system, and a voltage regulator selection unit that selects one or more voltage regulators from a predetermined number of candidate voltage regulators based on the power saving judgment index data.

Description

[Technical field]

[0001] The present invention relates to the selection of a voltage regulator suitable for saving power in a power distribution system, and to an estimation of the power saving effect when the selected voltage regulator is installed in the power distribution system. [Background technology]

[0002] From the viewpoint of energy conservation, there is a demand for power saving in low-voltage power distribution systems that are connected to a high-voltage power distribution system (commercial power source) and to which individual consumers connect various electrical appliances. Power saving in low-voltage power distribution systems can be achieved by providing a voltage regulator (power saver) on the upstream side of the low-voltage power distribution system of the consumer connected to the high-voltage power distribution system (for example, in a distribution board to which each appliance is connected).

[0003] An automatic voltage control device is already known that converts an input voltage into a predetermined output voltage in a voltage converter based on the input voltage and input current between input terminals to which a commercial power source is connected and the output voltage between output terminals to which various electrical devices are connected, and that can calculate a power saving rate by multiplying the rate of change of input power consumption by the rate of change of the output voltage (see, for example, Patent Document 1).

[0004] Known voltage regulators include a mechanical transformer with an automatic tap changer, also known as an SVR (Step Voltage Regulator), a slow-speed semiconductor type called a TSC (Thyristor Switched Capacitor), and a fast semiconductor type called an SVG (Static Var Generator). However, which voltage regulator will provide the most power savings for each customer's equipment depends on the connection and operating conditions.

[0005] However, in the past, the necessary voltage adjustment capacity (adjustment amount, adjustment speed, adjustment frequency, etc.) was unknown in advance, and therefore the power saving effect of a voltage regulator could not be confirmed unless the voltage regulator was actually installed, as disclosed in Patent Document 1. As a result, a voltage regulator with excessive specifications (capacity, weight, etc.) was installed, which could result in unnecessarily high installation and construction costs. Alternatively, a voltage regulator with inappropriate capacity was installed, which could result in no power saving effect being obtained.

[0006] One possible solution would be to temporarily install a potential voltage regulator and then confirm and examine its power saving effect, but this would entail problems such as the time, cost and effort required for installation. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4249578 Summary of the Invention

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a method that makes it possible to select a voltage regulator suitable for power saving at a consumer's facility without installing the regulator, and to estimate the power saving effect that would be achieved if the selected voltage regulator were installed in a power distribution system.

[0009] In order to solve the above problems, a first aspect of the present invention is an apparatus for selecting a voltage regulator for power saving at an electricity consumer having electrical equipment connected to a low-voltage distribution system, the apparatus comprising: a power saving judgment index data generation unit that generates power saving judgment index data serving as a judgment index when selecting the voltage regulator, based on historical data of power and voltage at a candidate installation location of the voltage regulator on the low-voltage distribution system or alternative data for the historical data; and a voltage regulator selection unit that selects one or more voltage regulators from a predetermined number of candidate voltage regulators based on the power saving judgment index data.

[0010] A second aspect of the present invention is a voltage regulator selection device according to the first aspect, further comprising an estimated power saving amount calculation unit that generates ideal estimated power saving amount data, which is time-dependent data of an ideal estimated power saving amount when the one or more voltage regulators are installed at the candidate installation locations, based on the power saving determination index data.

[0011] A third aspect of the present invention is a voltage regulator selection device according to the second aspect, characterized in that the estimated power saving calculation unit further generates effective estimated power saving data, which is time-dependent data of an effective estimated power saving obtained by subtracting power loss in the one or more voltage regulators from the ideal estimated power saving.

[0012] A fourth aspect of the present invention is the voltage regulator selection device according to the first or second aspect, wherein the power saving determination index data generation unit generates PV characteristic index data, which is time-lapse data of a ratio of a power change per unit power to a voltage change per unit voltage at the candidate installation location, based on the time-lapse data or the alternative data; generates voltage target value data, which is time-lapse data of a voltage value at the candidate installation location when power consumption of the equipment is minimized while keeping an operation status of the equipment substantially the same as when the time-lapse data is obtained, based on the PV characteristic index data and a management range of voltage in the low-voltage distribution system; and generates ideal voltage adjustment amount data, which is time-lapse data of an adjustment amount from an actual voltage value at the candidate installation location when the equipment is operated in accordance with the voltage target value data while keeping an operation status of the equipment substantially the same as when the time-lapse data is obtained, based on the voltage target value data; and the voltage regulator selection unit selects the one or more voltage regulators based on the ideal voltage adjustment amount data.

[0013] A fifth aspect of the present invention is the voltage regulator selection device according to the fourth aspect, wherein the power saving determination index data generation unit generates, as the PV characteristic index data, time-lapse data of a PV characteristic index α obtained by an equation α=(1-P / P0) / (1-V / V0), where P and V are power and voltage values ​​measured at an arbitrary timing in the time-lapse data of power and voltage at the installation candidate position, respectively, and P0 and V0 are power and voltage values ​​measured immediately before the arbitrary timing, respectively, and generates the ideal voltage adjustment amount data based on the voltage target value data and the time-lapse data of voltage at the installation candidate position.

[0014] A sixth aspect of the present invention is the voltage regulator selection device according to the fifth aspect, characterized in that the power saving determination index data generation unit calculates the PV characteristic index α only for timing at which a difference value between V and V0 in the time-lapse data of voltage at the candidate installation location was equal to or greater than a predetermined reference value, and for timing at which the difference value does not exceed the reference value, sets the value of the PV characteristic index α to be the same as the value at the immediately preceding timing.

[0015] A seventh aspect of the present invention is the voltage regulator selection device according to the fourth aspect, wherein the power saving determination index data generation unit generates composite power data, which is the alternative data for the power over time data at the candidate installation location, by synthesizing power over time data of individual equipment included in the equipment, and generates the PV characteristic index data based on the composite power data, the power over time data of the individual equipment, and an index value of power-voltage characteristics for the individual equipment, which is fixedly determined in advance according to a type of the individual equipment.

[0016] An eighth aspect of the present invention is a voltage regulator selection device according to the fourth aspect, characterized in that the candidate voltage regulators are a mechanical voltage regulator, a semiconductor low speed voltage regulator, and a semiconductor high speed voltage regulator, and the voltage regulator selection unit selects the one or more voltage regulators based on the number of voltage changes in the ideal voltage adjustment amount data and whether or not there is a voltage change in the ideal voltage adjustment amount data that is greater than or equal to a predetermined value.

[0017] A ninth aspect of the present invention is a voltage regulator selection program which, when executed by a computer, causes the computer to function as a voltage regulator selection device for selecting a voltage regulator for power saving at an electricity consumer having electrical equipment connected to a low-voltage distribution system, the voltage regulator selection device including: a power saving judgment index data generation unit that generates power saving judgment index data serving as a judgment index when selecting the voltage regulator, based on historical data of power and voltage at a candidate installation location of the voltage regulator on the low-voltage distribution system or alternative data for the historical data; and a voltage regulator selection unit that selects one or more voltage regulators from a predetermined number of candidate voltage regulators based on the power saving judgment index data.

[0018] A tenth aspect of the present invention is a method for selecting a voltage regulator for power saving at an electricity consumer having electrical equipment connected to a low-voltage distribution system, comprising: a power saving judgment index data generation step of generating power saving judgment index data serving as a judgment index when selecting the voltage regulator, based on historical data of power and voltage at a candidate installation location of the voltage regulator on the low-voltage distribution system or alternative data for the historical data; and a voltage regulator selection step of selecting one or more voltage regulators from a predetermined number of candidate voltage regulators based on the power saving judgment index data.

[0019] According to the first to tenth aspects of the present invention, it is possible to select a voltage regulator suitable for saving electricity by voltage regulation at a consumer facility, without actually installing a voltage regulator.

[0020] In particular, according to the second and third aspects, it is possible to judge the effect of power saving associated with the introduction of a voltage regulator. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a power system 10. [Diagram 2] FIG. 1 is a block diagram showing a configuration of a voltage regulator selecting device 100. [Diagram 3] 1 is a diagram showing functional components virtually included in voltage regulator selection device 100, together with the flow of data processed in voltage regulator selection device 100. FIG. [Figure 4] 3 is a diagram showing a schematic flow of processing in a voltage regulator selecting device 100. FIG. [Diagram 5] FIG. 11 is a diagram showing a process flow relating to generation of power saving determination index data. [Figure 6] FIG. 11 is a diagram showing a process flow relating to the selection of a voltage regulator. [Figure 7] FIG. 13 is a diagram illustrating power data DP. [Figure 8] FIG. 13 is a diagram illustrating an example of voltage data DV. [Figure 9] FIG. 4 is a diagram illustrating an example of PV characteristic index data Dα in the first embodiment. [Figure 10] FIG. 13 is a diagram illustrating an example of corrected PV characteristic index data Dα. [Figure 11] FIG. 13 is a partial enlarged view of a part of a time range of the corrected PV characteristic index data Dα. [Figure 12] 4 is a partial enlarged view of voltage target value data DVt in the first embodiment. FIG. [Figure 13] 4 is a partial enlarged view of ideal voltage adjustment amount data DVr in the first embodiment. FIG. [Figure 14] 4 is a partial enlarged view of ideal estimated power saving amount data DPs in the first embodiment. FIG. [Figure 15] FIG. 13 is a diagram showing a graph of power data DP in the first embodiment together with a graph of ideal power-saving power data DP0. [Figure 16] 5 is a diagram showing an amount of change in ideal voltage adjustment amount Vr in the first embodiment. FIG. [Figure 17] FIG. 2 is a diagram showing a graph of effective saved power data DP1 in the first embodiment together with a graph of power data DP. [Figure 18] FIG. 13 is a diagram illustrating an example of PV characteristic index data Dα in the second embodiment. [Figure 19] FIG. 11 is a partial enlarged view of a part of a time range of PV characteristic index data Dα in the second embodiment. [Figure 20] 13 is a partial enlarged view of ideal voltage adjustment amount data DVr in the second embodiment. FIG. [Figure 21] 13 is a partial enlarged view of ideal estimated power saving amount data DPs in the second embodiment. FIG. [Figure 22] FIG. 13 is a diagram showing a graph of power data DP and a graph of ideal power-saving power data DP0 in the second embodiment. [Figure 23] FIG. 11 is a diagram showing the amount of change in ideal voltage adjustment amount Vr in the second embodiment. [Figure 24] FIG. 1 is a diagram illustrating a schematic configuration of a power system 20. [Diagram 25] FIG. 2 is a block diagram showing a configuration of a voltage regulator selecting device 200. [Figure 26] 4 is a diagram showing a schematic flow of processing in a voltage regulator selecting device 200. FIG. [Figure 27] 10 is a diagram showing individual power data DPi of each of the individual facilities A to D. FIG. [Figure 28] FIG. 13 is a diagram showing composite power data DC. [Figure 29] FIG. 13 is a diagram showing PV characteristic index data Dα in the third embodiment. [Diagram 30] FIG. 13 is a diagram showing a process flow relating to selection of a voltage regulator in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] <First embodiment> The first embodiment of the present invention will generally explain the selection of an optimal voltage regulator when introducing a voltage regulator at an electricity consumer for the purpose of saving energy through voltage adjustment, and the estimation of the amount of energy saved when the selected voltage regulator is used.

[0023] It is anticipated that such selection and estimation will be carried out by the consumers themselves, and also by businesses known as energy saving consultants or power saving consultants when proposing power saving measures to consumers.

[0024] <Outline of the power system> FIG. 1 is a diagram illustrating a schematic configuration of a power system 10 including electrical equipment of a consumer in which a voltage regulator according to a first embodiment of the present invention is to be introduced.

[0025] The power system 10 is generally a system that transmits and distributes electricity to a large number of consumers (more specifically, the electrical equipment owned by each consumer, the same applies below) via a high-voltage distribution system 1 and a low-voltage distribution system 2 connected thereto. In the power system 10, the voltage sent from the high-voltage distribution system 1 is stepped down in a transformer 3a provided in a substation facility 3.

[0026] In addition, in Fig. 1, the low-voltage distribution system 2 branches into five individual distribution systems 2a, 2b, 2c, 2d, and 2e corresponding to the individual consumers, and each is provided with a distribution board 4 (4a, 4b, 4c, 4d, and 4e). Electrical equipment owned by each consumer is appropriately connected to each distribution board 4. Note that the number of individual distribution systems branching off from the low-voltage distribution system 2 is not limited to five.

[0027] In the low-voltage distribution system 2, the voltage value is managed within a certain control range that includes a predetermined standard voltage. This is the same for each individual distribution system. For example, when the voltage in the high-voltage distribution system 1 is 6.6 kV, the standard voltage in the low-voltage distribution system 2 is 101 V or 202 V, and in the former case, the control range is 95 V to 107 V, and in the latter case, the control range is 180 V to 220 V.

[0028] In this embodiment, a case will be described in which a voltage regulator is selected for the purpose of saving electricity, without actually installing and confirming the effect, for a consumer who receives electricity from a certain individual power distribution system 2a connected to the high-voltage power distribution system 1 in the above-described manner. Fig. 1 shows a case in which four electrical facilities (individual facilities) A, B, C, and D are connected in parallel to a distribution board 4a by the consumer. In the following description, these four individual facilities A to D will be collectively referred to simply as facility 5.

[0029] In this case, a position in the individual power distribution system 2a and upstream of the equipment 5 in the distribution board 4 becomes a candidate installation position 6 for installing a voltage regulator for power saving purposes.

[0030] Generally speaking, the consumer-owned facilities 5 (individual facilities A to D) operate as a whole within the above-mentioned control range according to the power-voltage characteristics (hereinafter, PV characteristics) according to the overall operating conditions, but if the operating conditions are constant, power consumption can be reduced by controlling the voltage at the candidate installation location 6 so that the power value at the candidate installation location 6 is minimized within the control range. In other words, power can be saved compared to when such control is not performed.

[0031] In this embodiment, a voltage regulator suitable for installation for the purpose of saving electricity is selected, including whether installation is necessary, based on the power value and voltage value at the candidate installation position 6. In the following, for ease of explanation, the selection of a voltage regulator may be used to include cases where it is determined that installation is unnecessary. Furthermore, based on past actual values ​​of power and voltage, an estimated amount of electricity saved is also calculated assuming that the selected voltage regulator was used when the equipment was in operation when those actual values ​​were obtained.

[0032] <Voltage regulator selection device> 2 is a block diagram showing the configuration of a voltage regulator selection device 100 according to this embodiment. As described above, the voltage regulator selection device (hereinafter also simply referred to as the selection device) 100 is a device that selects a voltage regulator for the purpose of saving power, without actually installing the regulator and confirming the effect, for consumers who receive power from a certain individual power distribution system 2a, and calculates an estimated amount of power saving that would occur if the selected voltage regulator were installed. The selection device 100 can be realized by a general-purpose or dedicated computer. Therefore, as shown in FIG. 2, the selection device 100 mainly comprises a control unit 101 having a CPU 101a, a ROM 101b, and a RAM 101c and controlling the operation of each part of the selection device 100, an input unit 102 including an input device such as a keyboard, a mouse, or a touch panel for the operator of the selection device 100 to input necessary information and perform processing operations, a display unit 103 including a display device such as a display for displaying the operation contents and selection results of the selection device 100, a memory unit 104 including a memory device such as a hard disk for storing programs or information necessary for various operations of the selection device 100 and processing results, a communication unit 105 including a communication device for communicating with the outside via the Internet, an intranet, etc., in a wired or wireless manner, and an R / W unit 106 for reading and / or writing data to and from portable storage media such as a USB, CD-ROM, DVD-ROM, DVD-RAM, and an external hard disk.

[0033] In the voltage regulator selection device 100, a predetermined operating program stored in the ROM 101b, the RAM 101c or the memory unit 104 is read into the CPU 101a and executed, thereby virtually realizing various functional components related to the selection of a voltage regulator and the calculation of an estimated amount of power saving.

[0034] FIG. 3 is a diagram showing functional components virtually included in the selection device 100 according to the present embodiment, together with the flow of data processed in the selection device 100. As shown in FIG.

[0035] The selection device 100 includes, as functional components, a time-course data acquisition unit 111, a power-saving determination index data generation unit 112, an estimated power-saving amount calculation unit 113, and a voltage regulator selection unit 114.

[0036] The time-course data acquiring unit 111 acquires power data DP and voltage data DV which are time-course data (data showing changes over time) of power P and voltage V at the installation position candidate 6 for a voltage regulator in the power system 10 described above.

[0037] The power saving determination index data generating unit 112 sequentially generates data (power saving determination index data) required for selecting a voltage regulator and calculating an estimated power saving amount, based on the power data DP and voltage data DV acquired by the time-dependent data acquiring unit 111 and the voltage management data Dr input in advance and stored in the storage unit 104. Here, the voltage management data Dr is data including a standard voltage VS in the low-voltage distribution system 2, and a lower limit VL and an upper limit VH of the management range.

[0038] Specifically, the power saving determination index data generating unit 112 generates PV characteristic index data Dα, voltage target value data DVt, and ideal voltage adjustment amount data DVr. The details of these data will be described later.

[0039] The estimated power saving amount calculation unit 113 generates time-series data of the amount of power saving that is estimated to have been possible if power saving had been performed in the customer facility 5 at the time the power data DP and the voltage data DV were acquired.

[0040] Specifically, the estimated power-saving amount calculation unit 113 generates ideal estimated power-saving amount data DPs and effective estimated power-saving amount data DPw. The ideal estimated power-saving amount data DPs is time-dependent data of an ideal estimated power-saving amount Ps, which is the maximum estimated power-saving amount obtained by calculation, and the effective estimated power-saving amount data DPw is time-dependent data of an effective estimated power-saving amount Pw, which is an estimated power-saving amount taking into account power loss in the voltage regulator selected by the voltage regulator selection unit 114.

[0041] The voltage regulator selection unit 114 selects a voltage regulator that is optimal for power saving in the consumer facility 5. The voltage regulator selection unit 114 selects the voltage regulator based on the ideal voltage adjustment amount data DVr generated in the power saving determination index data generation unit 112, and generates selection result data Ds describing the results of the selection. The selection result data Ds also appropriately describes the characteristics (specifications) of the selected voltage regulator, which are described in the regulator characteristic data Dsp.

[0042] Depending on the contents of the ideal voltage adjustment amount data DVr, the voltage regulator selection unit 114 may determine that it is not necessary to select a voltage regulator. Hereinafter, this will be referred to as selection of a voltage regulator, including such cases.

[0043] <Processing flow> Next, a process for selecting a voltage regulator and calculating an estimated power saving amount, which is performed in the selection device 100 having the above-mentioned configuration, will be described with a concrete example. In the following, it is assumed that the standard voltage VS is 202V, the lower limit VL of the control range is 180V, and the upper limit VH is 220V.

[0044] 4 is a diagram showing a schematic flow of processing in the selection device 100. In the selection device 100, in response to a predetermined execution instruction given by an operator through the operation of the input unit 102, first, various power saving determination index data are generated in sequence (step S100), and then a voltage regulator is selected (step S200) and effective estimated power saving amount data DPw is generated (step S300).

[0045] Fig. 5 is a diagram showing a process flow relating to generation of power saving determination index data Fig. 6 is a diagram showing a process flow relating to selection of a voltage regulator.

[0046] (Generation of energy saving judgment index data) As shown in FIG. 5, when generating the power saving determination index data, first, the historical data acquisition unit 111 acquires power data DP and voltage data DV, which are historical data of actual values ​​of power P and voltage V in the consumer facility 5 (step S101).

[0047] The power data DP and voltage data DV may be acquired by actually connecting the selection device 100 to the candidate installation location 6 and actually measuring the power P and voltage V at the candidate installation location 6 at predetermined sampling intervals over a certain sampling time (e.g., 24 hours), or by acquiring, via the communication unit 105 or the R / W unit 106, the power data DP and voltage data DV that have already been generated by a consumer or other party performing similar measurements in advance.

[0048] There is no particular limit to the sampling time, but if the operating status of the equipment 5 changes periodically, for example, on a daily (24-hour) basis, it is a preferred embodiment to set the sampling time to include such a period. The sampling interval may be appropriately set within a range of several milliseconds to several minutes, taking into consideration the operating status of the equipment 5 and the measurement time.

[0049] 7 and 8 are diagrams illustrating examples of power data DP and voltage data DV, respectively. The sampling time is 24 hours (specifically, from 10:00 on one day to 10:00 on the next day), and the sampling interval is 1 second.

[0050] When the time-course data acquiring unit 111 acquires the power data DP and the voltage data DV, next, the power saving determination index data generating unit 112 generates the PV characteristic index data Dα (step S102).

[0051] The PV characteristic index data Dα is time-dependent data of a PV characteristic index α, which is an index characterizing the PV characteristics in the facility 5 used by the consumer.

[0052] In this embodiment, the PV characteristic index α is the ratio of the power change per unit power to the voltage change per unit voltage. In this embodiment, when the power value and voltage value measured at an arbitrary sampling timing are P and V, respectively, and the power value and voltage value measured at the immediately preceding sampling timing are P0 and V0, respectively, the PV characteristic index α is expressed as follows: α=(1-P / P0) / (1-V / V0) ···(1) It is defined by the following formula.

[0053] The PV characteristic index α is a value that changes from moment to moment in response to changes in the PV characteristics accompanying changes in the operating status of the equipment 5, and is a value that indicates the PV characteristics of the equipment 5 at each sampling timing.

[0054] The power saving determination index data generating unit 112 generates PV characteristic index data Dα, which is time-dependent data of the PV characteristic index α, by sequentially performing the calculation of the formula (1) based on the power data DP and the voltage data DV over the entire measurement time of the power and the voltage. Fig. 9 is a diagram illustrating the PV characteristic index data Dα obtained from the power data DP shown in Fig. 7 and the voltage data DV shown in Fig. 8.

[0055] Typically, the PV characteristics of each of the individual facilities A to D of the facility 5 are classified into three types, namely, a constant resistance characteristic, a constant current characteristic, and a constant power characteristic, depending on the type of the facility. Therefore, the PV characteristic index α is a value according to the combination of the PV characteristics of the individual facilities of the facility 5 that are in operation.

[0056] For example, in an individual facility where the PV characteristic is a constant resistance characteristic, if the impedance is Z, then between the power value P and the voltage value V, P=V 2 / Z (2) The following relational expression holds. Similarly, between the power value P0 and the voltage value V0, P0=(V0) 2 / Z ···(2α) The following relational expression holds. Substituting these equations into equation (1), unless V = V0, α=(1-V 2 / (V0) 2 ) / (1-V / V0) =1+V / V0 ···(3) However, since both the voltage values V and V0 are within the control range, in equation (3), at most, V / V0 = about 0.8 to 1.2. Therefore, it can be said that α is approximately 2 from equation (3).

[0057] Also, in individual equipment where the P-V characteristic is a constant current characteristic, if the current value is I, between the power value P and the voltage value V, P=V·I ···(4) The following relational expression holds. Similarly, between the power value P0 and the voltage value V0, P0=V0·I ···(4α) The following relational expression holds. Substituting these equations into equation (1), α=(1-V·I / V0·I) / (1-V / V0) =1 ···(5) It becomes as follows.

[0058] On the other hand, in individual equipment where the P-V characteristic is a constant power characteristic, P=P0=constant ···(6) In this case, in equation (1), α = 0.

[0059] Therefore, the P-V characteristic index α is approximately a value in the range of 0 to 2. However, the actual P-V characteristic in equipment 5 may take a value outside this range due to losses in the internal components of individual equipment A to D. For example, when V > V0 and P < P0, α becomes a negative value. Hereafter, as long as the P-V characteristic index α is a value within the range of -1 ≦ α ≦ 3, it is considered to reflect the actual P-V characteristic, and this range is referred to as the reference range of the P-V characteristic index α.

[0060] However, when the power saving determination index data generating unit 112 actually calculates the formula (1), the calculation result of the PV characteristic index α for the sampling timing may not fall within the above-mentioned reference range due to fluctuations in the power value and voltage value, reading errors, etc. In the case of the PV characteristic index data Dα shown in Fig. 9, the PV characteristic index α also fluctuates to about ±1000.

[0061] When such a calculation result is obtained, the power saving determination index data generating unit 112 sets the average value of the calculation values ​​for the previous and following sampling timings as the value of the PV characteristic index α at that sampling timing. This is because it is considered that a value of the PV characteristic index α that exceeds the reference range cannot be said to correctly represent the PV characteristics at the sampling timing at which the value was obtained. It is not preferable to use such a value as it is, since it may result in inappropriate selection of a voltage regulator and calculation of an estimated power saving amount. As a result, the PV characteristic index α becomes a value within the reference range of -1≦α≦3.

[0062] When the PV characteristic index α is within the reference range, its magnitude also serves as an index of the power saving effect of voltage regulation. In other words, the larger the PV characteristic index α, the steeper the slope of the PV characteristic, and therefore the greater the power saving effect that can be expected.

[0063] Fig. 10 is a diagram illustrating the PV characteristic index data Dα after the PV characteristic index data Dα shown in Fig. 9 has been corrected in this manner. Fig. 11 is a partial enlarged view of a part of the time range (from 14:00 to 14:10) of the corrected PV characteristic index data Dα shown in Fig. 10. In the following, unless otherwise specified, it is assumed that the above-mentioned correction is performed on the PV characteristic index data Dα when the value of the PV characteristic index α falls outside the reference range.

[0064] When the PV characteristic index data Dα is obtained in this manner, the power saving determination index data generating unit 112 then generates voltage target value data DVt. The voltage target value data DVt is time-dependent data of the voltage target value Vt, which is a voltage value that should be set when minimizing (reducing) power consumption while maintaining substantially the same operating conditions in the consumer facility 5 that has actually been operated by applying the voltage value recorded in the voltage data DV.

[0065] In other words, if the consumer's equipment 5 had been operated entirely in accordance with the voltage target value data DVt, the equipment 5 would have operated in the same manner as in reality with the minimum possible power, and as a result, the power consumption would have been reduced to the maximum extent possible from the actual power P.

[0066] The power saving determination index data generating unit 112 generates voltage target value data DVt based on the PV characteristic index data Dα and the lower limit VL and upper limit VH of the management range of the voltage V described in the voltage management data Dr (step S103).

[0067] Specifically, the power saving determination index data generating unit 112 sets Vt=VL for the sampling timing where 0<α≦3, while setting Vt=VH for the sampling timing where −1≦α≦0.

[0068] This is based on the fact that, according to equation (1), when 0<α≦3, the power P has a monotonically increasing relationship with the voltage V in the PV characteristics, so that the power P is minimum when the voltage V is at the lower limit VL within the control range, and when -1≦α≦0, the power P has a monotonically decreasing relationship with the voltage V in the PV characteristics, so that the power P is minimum when the voltage V is at the upper limit Vh within the control range.

[0069] Strictly speaking, it is possible that the PV characteristics change like an n-th order function (curve-like) in the case of constant resistance characteristics, etc., and the power P becomes minimal at a voltage V other than the upper and lower limits within the control range, but it is difficult to identify the actual PV characteristics, which may change from moment to moment, at each sampling timing, and in fact, in most cases the PV characteristics change monotonically (linearly). In light of the purpose of this embodiment, which is to select a voltage regulator suitable for saving power and to calculate the estimated amount of power saved, there is no problem with setting the voltage target value Vt as described above.

[0070] The power saving determination index data generating unit 112 generates the voltage target value data DVt by determining the voltage target value Vt based on the value of α over the entire sampling time.

[0071] FIG. 12 is a partially enlarged view of the voltage target value data DVt generated based on the (corrected) PV characteristic index data Dα shown in FIG. 10, for the same time range as in FIG.

[0072] When the voltage target value data DVt is obtained in this manner, the power saving determination index data generating unit 112 subsequently generates ideal voltage adjustment amount data DVr (step S104). The ideal voltage adjustment amount data DVr is time-series data of the ideal voltage adjustment amount Vr, which is the amount of adjustment from the actual voltage value, in the case where the consumer's facility 5 that actually operates in the manner described in the power data DP and the voltage data DV is operated completely in accordance with the voltage target value data DVt while maintaining substantially the same operating conditions.

[0073] The ideal voltage adjustment amount Vr is the ideal voltage adjustment amount that the voltage regulator should make in order to save power when the voltage regulator is actually installed at the candidate installation position 6 for the voltage regulator.

[0074] In this embodiment, the ideal voltage adjustment amount Vr at a certain sampling timing is expressed as follows: Vr = Vt - V (7) The formula is as follows:

[0075] The power saving determination index data generating unit 112 generates ideal voltage adjustment amount data DVr by performing calculations according to equation (7) over the entire sampling time.

[0076] FIG. 13 is a partially enlarged view of the ideal voltage adjustment amount data DVr generated by the power saving determination index data generating unit 112 by performing a calculation according to equation (7) on the voltage data DV shown in FIG. 8 and the voltage target value data DVt partially shown in FIG. 12, for the same time range as in FIGS. 11 and 12.

[0077] When the ideal voltage adjustment amount data DVr is obtained in this manner, the voltage regulator selection unit 114 selects a voltage regulator based on the ideal voltage adjustment amount data DVr (step S200). The ideal voltage adjustment amount data DVr is also used in the generation of ideal estimated power-saving amount data DPs by the estimated power-saving amount calculation unit 113 (step S105). It does not matter which order the selection of the voltage regulator is performed before the generation of the ideal estimated power-saving amount data DPs.

[0078] (Calculation of ideal estimated power saving amount) As described above, the ideal estimated power saving amount data DPs is time-dependent data of the ideal estimated power saving amount Ps, which is the maximum estimated power saving amount obtained by calculation.

[0079] If the PV characteristic index α is used between the ideal estimated power saving amount Ps and the ideal voltage adjustment amount Vr at a certain sampling timing and the power P and voltage V at the sampling timing, Ps / |Vr|=|α|·P / V A relationship like this is established.

[0080] Therefore, the ideal estimated power saving amount Ps is Ps = |α Vr| P / V (8) It can be calculated using the following formula:

[0081] The estimated power saving amount calculation unit 113 generates ideal estimated power saving amount data DPs by performing calculations based on the PV characteristic index data Dα, the ideal voltage adjustment amount data DVr, the power data DP, and the voltage data DV over the entire sampling time based on equation (8).

[0082] Fig. 14 is a partially enlarged view of ideal estimated power-saving amount data DPs generated by the estimated power-saving amount calculation unit 113 using the PV characteristic index data Dα shown in Fig. 10, the ideal voltage adjustment amount data DVr partly shown in Fig. 13, the power data DP shown in Fig. 7, and the voltage data DV shown in Fig. 8, over the same time range as Figs. 11 to 13. Fig. 15 is a view showing a graph of the power data DP and a graph of ideal saved power data DP0, which is data of the difference value between the power P and the ideal estimated power-saving amount Ps, over the same time range as Fig. 14. The ideal saved power data DP0 corresponds to time-dependent data of ideal power consumption when power saving is performed in real time by a voltage regulator.

[0083] The ideal estimated power saving amount Ps is a value calculated according to formula (8) and is not related to the selection result of the voltage regulator described below. This means that the ideal power saving amount that is estimated to have been possible in the consumer's facility 5 that was operating with the actual values ​​recorded in the power data DP and voltage data DV can be estimated from the actual values ​​of the power data DP and voltage data DV, regardless of the selection of the voltage regulator.

[0084] The generation of the ideal estimated power-saving amount data DPs by calculating the ideal estimated power-saving amount may be performed after the selection of a voltage regulator, which will be described below.

[0085] (Selection of a voltage regulator) Next, the selection of a voltage regulator suitable for installation at the installation candidate position 6 for power saving, performed by the voltage regulator selection unit 114, will be described.

[0086] Mechanical and semiconductor voltage regulators are widely known as voltage regulators, and it is also known that semiconductor voltage regulators are further classified into high-speed and low-speed types. In this embodiment, the mechanical voltage regulator, the low-speed semiconductor voltage regulator, and the high-speed semiconductor voltage regulator are selected as candidates for selection by voltage regulator selection unit 114. The characteristics (specifications) of each voltage regulator are described in advance in regulator characteristic data Dsp and stored in storage unit 104.

[0087] More specifically, it is assumed that the mechanical voltage regulator has a voltage adjustment amount of 2V / tap and ±2tap, a voltage adjustment speed (adjustment time) of 5 min, a voltage adjustment frequency of 30 times / 24 h, and a power loss Pls during voltage adjustment of 1% of power P. An example of such a mechanical voltage regulator is an SVR (Step Voltage Regulator: automatic voltage regulator).

[0088] In addition, it is assumed that the slow-speed semiconductor voltage regulator has a voltage adjustment speed (adjustment time) of 500 ms, no limit on the number of voltage adjustments, and no power loss during voltage adjustment (Pls=0%). An example of such a slow-speed semiconductor voltage regulator is a TSC (Thyristor Switched Capacitor).

[0089] On the other hand, for a high-speed semiconductor voltage regulator, it is assumed that the voltage adjustment speed (adjustment time) is 50 ms, there is no limit to the number of voltage adjustments, and the power loss Pls during voltage adjustment is 1% of the power P. An example of such a low-speed semiconductor voltage regulator is a static var generator (SVG).

[0090] These three types of voltage regulators differ primarily in the number of voltage adjustments (per day) and the voltage adjustment speed (adjustment time). In this embodiment, taking this into consideration, a voltage regulator is selected basically based on the number of voltage changes appearing in the ideal voltage adjustment amount data DVr. As described above, the ideal voltage adjustment amount Vr described in the ideal voltage adjustment amount data DVr is the ideal voltage adjustment amount that the voltage regulator should adjust to save power, so the voltage regulator to be installed at the installation candidate position 6 must be one that is determined to be actually capable of adjusting the voltage in accordance with the voltage changes appearing in the ideal voltage adjustment amount data DVr.

[0091] Specifically, as shown in FIG. 6, the voltage regulator selection unit 114 first counts the number of times (the number of voltage changes) that the change (difference value) in the value of the ideal voltage adjustment amount Vr at a certain sampling timing from the value of the ideal voltage adjustment amount Vr at the immediately preceding sampling timing is ±2V or more in the ideal voltage adjustment amount data DVr (step S201).

[0092] Fig. 16 is a diagram showing the amount of change in the ideal voltage adjustment amount Vr corresponding to the ideal voltage adjustment amount data DVr in the time range shown in Fig. 13. The number of times a change of ±2V or more occurs in such a profile of the difference value is counted by the voltage regulator selection unit 114. To be sure, there are several peaks in the ideal voltage adjustment amount Vr in Fig. 13, but when the voltage regulator selection unit 114 counts the number of voltage changes, each of the increases and decreases in the ideal voltage adjustment amount Vr that give these peaks is counted.

[0093] Then, the voltage regulator selection unit 114 performs a first determination for selecting a voltage regulator suitable for installation at the installation candidate position 6 for power saving based on the counted number of voltage changes (step S202).

[0094] First, when it is determined that the number of voltage changes is once or less per day, the voltage regulator selection unit 114 determines that installation of a voltage regulator is unnecessary.

[0095] On the other hand, if it is determined that the number of voltage changes is 2 times or more and less than 30 times per day, the voltage regulator selection unit 114 selects a mechanical voltage regulator as a candidate for the voltage regulator to be installed at the installation candidate position 6.

[0096] Furthermore, if it is determined that the number of voltage changes is 30 or more per day, voltage regulator selection unit 114 first selects a semiconductor-type voltage regulator as a candidate for a voltage regulator to be installed at candidate installation position 6. Then, a second determination is made to select either a high-speed type or a low-speed type as the candidate based on the presence or absence of a voltage change of 9 V or more that appears in ideal voltage adjustment amount data DVr (step S203).

[0097] If it is determined that the ideal voltage adjustment amount data DVr includes a voltage change of 9 V or more, the voltage regulator selection unit 114 selects a high-speed semiconductor voltage regulator as a candidate for the voltage regulator to be installed at the installation candidate position 6.

[0098] On the other hand, if it is determined that the ideal voltage adjustment amount data DVr does not include a voltage change of 9 V or more, the voltage regulator selection unit 114 selects a low-speed semiconductor voltage regulator as a candidate for the voltage regulator to be installed at the installation candidate position 6.

[0099] Through the above procedure, the selection device 100 selects candidates for voltage regulators suitable for installation at the candidate installation locations 6 for the purpose of saving power in the consumer facility 5, and the voltage regulator selection unit 114 generates selection result data Ds describing the results. The selection result data Ds is displayed on the display unit 103 in an appropriate format.

[0100] The total number of voltage changes in the ideal voltage adjustment amount data DVr, the partial enlarged view of which is shown in Fig. 13, was 3988 times / day, of which 3957 times / day were voltage changes of 9 V or more. Therefore, for facility 5 from which the power data DP and voltage data DV of Fig. 7 and Fig. 8 on which the ideal voltage adjustment amount data DVr is based were obtained, a semiconductor-type high-speed voltage regulator is selected as a candidate for the voltage regulator to be installed at candidate installation location 6.

[0101] If the selected voltage regulator is actually installed at the candidate installation location 6 and adjusts the value of the voltage V in accordance with the ideal voltage adjustment amount data DVr, it can be estimated that power saving has been achieved according to the ideal estimated power saving amount Ps described in the ideal estimated power saving amount data DPs.

[0102] Although the ideal estimated power saving data DPs is obtained from the past power data DP and voltage data DV, it can be said that if the consumer's facility 5 operates in the future in the same way as when the power data DP and voltage data DV were obtained, the same level of power saving can be achieved by operating the voltage regulator selected accordingly. This means that the ideal estimated power saving amount Ps described in the ideal estimated power saving data DPs also corresponds to the expected value of the power saving amount that can be obtained if the selected voltage regulator is actually installed at the installation candidate position 6.

[0103] (Calculation of effective estimated power saving amount) However, as described above, depending on the selected voltage regulator, when it is actually installed and used at the installation candidate location 6, a power loss may occur at a certain rate during voltage adjustment for power saving. In order to make the power saving effect of installing a voltage regulator more effective, it is desirable to take such a power loss into consideration.

[0104] Therefore, in this embodiment, the effective estimated power saving amount Pw, which is a more effective estimated value of the power saving amount that takes voltage loss into account, is also calculated, and this can also be presented as information related to the selection of a voltage regulator.

[0105] Specifically, the estimated power saving calculation unit 113 acquires the selection result data Ds from the voltage regulator selection unit 114, and performs the following calculation over the entire sampling time based on the description content and the ideal estimated power saving data DPs previously generated, to generate effective estimated power saving data DPw, which is time-dependent data of the effective estimated power saving Pw.

[0106] Pw = Max{0,Ps-Pls} (9) Equation (9) means that when the amount of power loss Pls is greater than the ideal estimated amount of power saving Ps, no power is actually saved.

[0107] Fig. 17 is a diagram showing a graph of effective power-saving power data DP1, which is data obtained by subtracting the difference between the ideal estimated power saving amount Ps and the power loss amount Pls from the power P, together with a graph of the power data DP, instead of the graph of the ideal power-saving power data DP0 shown in Fig. 15. As described above, for the facility 5 from which the power data DP and voltage data DV in Fig. 7 and Fig. 8 were obtained, a semiconductor-type high-speed voltage regulator is selected as a candidate for the voltage regulator to be installed, so the power loss amount Pls in obtaining the effective power-saving power data DP1 shown in Fig. 17 is 1% of the value of power P described in the power data DP.

[0108] 17, for example, in some places as indicated by the arrows AR, the effective saved power data DP1 is greater than the ideal saved power data DP0. Therefore, in such places, even if the voltage regulator adjusts the voltage according to the ideal voltage adjustment amount data DVr, no power saving effect is actually obtained.

[0109] However, in the case illustrated in Figure 17, there are many locations where the effective energy-saving power data DP1 is sufficiently small in value compared to the power data DP. Therefore, if the equipment 5 operates in the same manner as when the power data DP was obtained, it is determined that sufficient energy saving effects can be expected by installing the semiconductor-type high-speed voltage regulator selected as a candidate at the installation candidate location 6.

[0110] As described above, even when a mechanical voltage regulator is selected, the power loss Pls of 1% of the power P must be taken into consideration. However, when a semiconductor low-speed voltage regulator is selected, there is no need to take the power loss into consideration.

[0111] In this way, by taking into account the power loss depending on the voltage regulator selected by voltage regulator selection unit 114, the effect of installing the selected voltage regulator can be determined more effectively.

[0112] As described above, according to this embodiment, when a voltage regulator is to be introduced into a low-voltage distribution system to which a consumer's equipment is connected for the purpose of saving energy, it is possible to select a voltage regulator that is suitable for the operating conditions of the consumer's equipment without actually installing a voltage regulator, and it is possible to calculate an estimated amount of energy saving that can be expected if the selected voltage regulator is installed.

[0113] That is, according to this embodiment, it is possible to select a voltage regulator suitable for power saving by voltage adjustment at the consumer and to judge the power saving effect of introducing the voltage regulator, without actually installing the voltage regulator. This makes it possible to prevent the installation of a voltage regulator with insufficient capacity, or conversely, the installation of a voltage regulator with excessive capacity.

[0114] <Second embodiment> In the above-described first embodiment, the PV characteristic index α is calculated for all sampling times of the power data DP and voltage data DV acquired by the time-course data acquisition unit 111, to generate the PV characteristic index data Dα.

[0115] However, as described above, when calculating the actual PV characteristic index α, there are cases where the calculation result of the PV characteristic index α for the sampling timing does not fall within the above-mentioned reference range due to errors in reading the power value and the voltage value, etc. In the first embodiment, this is corrected based on the reference range of -1≦α≦3, but even with this correction, fluctuations in small cycles remain, so the number of voltage adjustments in the ideal voltage adjustment amount data DVr is much greater than the number of times that serves as the judgment criterion (maximum 30 times / day). In view of the sampling time, it is more appropriate to consider that most of the voltage changes are caused by noise occurring in the power data DP and the voltage data DV rather than reflecting the actual operating status of the equipment 5.

[0116] In view of this, in this embodiment, the timing for calculating the PV characteristic index α is limited, and the effects of noise occurring in the power data DP and the voltage data DV are eliminated, so that the selection of a voltage regulator and the calculation of the estimated power saving amount are performed more efficiently. However, since the configuration of the voltage regulator selection device 100 in this embodiment may be the same as that in the first embodiment, and the processing flow is also roughly the same as in the first embodiment, the following description will focus on the differences from the first embodiment.

[0117] In this embodiment, when generating the PV characteristic index data Dα based on the power data DP and the voltage data DV acquired by the time-course data acquisition unit 111 (step S102), the power saving determination index data generation unit 112 calculates the PV characteristic index α based on the formula (1) only for the sampling time at which the V-V0 value exceeds 0.9%. The value of the PV characteristic index α for the sampling time at which the V-V0 value does not exceed 0.9% is set to the same as the value for the sampling time immediately preceding it. However, the reference value of 0.9% is merely an example, and another numerical value may be set.

[0118] Fig. 18 is a diagram illustrating PV characteristic index data Dα in this embodiment obtained under such conditions from the power data DP shown in Fig. 7 and the voltage data DV shown in Fig. 8. Also, Fig. 19 is a partial enlarged view of a part of the time range (from 14:00 to 14:10) of the PV characteristic index data Dα shown in Fig. 18.

[0119] It can be seen that the PV characteristic index data Dα shown in Figures 18 and 19 has less fluctuation and a smaller range of value fluctuation even without correction, compared to the PV characteristic index data Dα according to the first embodiment shown in Figures 9 (or Figures 10) and 11.

[0120] The subsequent processing is basically the same as that of the first embodiment. That is, the power saving determination index data generating unit 112 generates voltage target value data DVt based on the PV characteristic index data Dα shown in Fig. 18, and further generates ideal voltage adjustment amount data DVr by performing the calculation of formula (7) based on the voltage target value data DVt and the voltage data DV shown in Fig. 8. Fig. 20 is a partially enlarged view of the ideal voltage adjustment amount data DVr obtained in this manner, for the same time range as Fig. 19.

[0121] Furthermore, the estimated power-saving amount calculation unit 113 generates ideal estimated power-saving amount data DPs by performing calculation of equation (8) based on the ideal voltage adjustment amount data DVr shown in Fig. 20, the power data DP shown in Fig. 7, the voltage data DV shown in Fig. 8, and the PV characteristic index data Dα shown in Fig. 18. Fig. 21 is a partially enlarged view of the ideal estimated power-saving amount data DPs obtained in this manner, for the same time range as Fig. 19. Fig. 22 is a view showing a graph of the power data DP, for the same time range as Fig. 19, together with a graph of ideal saved power data DP2, which is data of the difference value between the power P and the ideal estimated power-saving amount Ps.

[0122] Figures 18 to 22 correspond to Figures 9 (or 10), 11, and 13 to 15 in the first embodiment, respectively, and it can be seen that in all of the data, fluctuations are suppressed compared to the first embodiment.

[0123] On the other hand, according to Figures 21 and 22, even when the ideal estimated power saving amount is calculated in the manner related to this embodiment, it is determined that power saving can be expected by installing a voltage regulator, as in the first embodiment.

[0124] Note that the time integral value of the ideal estimated power saving amount data DPs corresponds to an ideal amount of saved power, but the ideal estimated power saving amount data DPs shown in Fig. 21 differs from the ideal estimated power saving amount data DPs in the first embodiment shown in Fig. 14 in that the effects of noise in the power data DP and voltage data DV are eliminated at the time of generating the original PV characteristic index data Dα. Therefore, the time integral value of the ideal estimated power saving amount data DPs generated in this embodiment is considered to be more accurate and more likely as a value of the amount of saved power than the time integral value of the ideal estimated power saving amount data DPs generated in the first embodiment.

[0125] Furthermore, in this embodiment, as in the first embodiment, the voltage regulator selection unit 114 selects a candidate voltage regulator suitable for installation at the candidate installation location 6 based on the ideal voltage adjustment amount data DVr, in accordance with the procedure shown in FIG. 6.

[0126] Fig. 23 is a diagram showing the amount of change in the ideal voltage adjustment amount Vr at a certain sampling timing with respect to the ideal voltage adjustment amount Vr at the immediately preceding sampling timing for the ideal voltage adjustment amount data DVr obtained in this embodiment. Although Fig. 23 shows some small cycle fluctuations, most of the changes are less than 2V.

[0127] As a result, in the case of the ideal voltage adjustment amount data DVr obtained in this embodiment, the total number of voltage changes was 40 times / day, of which 9 times / day were voltage changes of 9 V or more. Therefore, also in this embodiment, for the equipment 5 from which the power data DP and voltage data DV in Fig. 7 and Fig. 8 were obtained, a semiconductor-type high-speed voltage regulator is selected as a candidate for the voltage regulator to be installed at the installation candidate location 6.

[0128] The subsequent calculation of the effective estimated power saving amount can also be performed in the same manner as in the first embodiment.

[0129] As explained above, in this embodiment, as in the first embodiment, when a voltage regulator is to be introduced into a low-voltage distribution system to which a consumer's equipment is connected for the purpose of saving energy, it is possible to select a voltage regulator suitable for the operating conditions of the consumer's equipment without actually installing a voltage regulator, and to calculate an estimated amount of energy saving expected if the selected voltage regulator is installed.

[0130] In other words, it is possible to select a voltage regulator suitable for saving energy through voltage adjustment at the consumer and to determine the effect of energy saving associated with the introduction of the voltage regulator, without actually installing a voltage regulator.

[0131] <Third embodiment> In the third embodiment of the present invention, a simpler method than the first embodiment is described for selecting an optimal voltage regulator for saving power through voltage adjustment, and estimating the amount of power saved when the selected voltage regulator is installed.

[0132] Like the first embodiment, this embodiment is also intended to be implemented by consumers themselves, as well as by businesses such as energy saving consultants and power saving consultants, but is particularly intended to be easily implemented by the latter businesses.

[0133] <Outline of the power system> FIG. 24 is a diagram illustrating a schematic configuration of a power system 20 including a customer facility 5 in which a voltage regulator according to the third embodiment of the present invention is to be introduced.

[0134] 1, the power system 20 is a system that transmits and distributes electricity to a large number of consumers through a high-voltage power distribution system 1 and a low-voltage power distribution system 2 connected thereto. Also in the power system 10, the voltage output from the high-voltage power distribution system 1 is stepped down in a transformer 3a provided in a power receiving and transforming facility 3.

[0135] However, in the power system 20, the low-voltage distribution system 2 branches into individual distribution systems 21 and 22. Four individual facilities A, B, C, and D as facilities 5 owned by one consumer are connected directly in parallel to the individual distribution system 21 without going through a distribution board 4. Also, it is assumed that individual facilities E and F owned by another consumer are connected in parallel to the individual distribution system 22.

[0136] Furthermore, in this embodiment, a position in the middle of the individual power distribution system 21 and upstream of the equipment 5 is set as a candidate installation position 6 when a voltage regulator is to be installed for power saving. Note that, although the candidate installation position 6 is set inside the power receiving and transforming equipment 3 in Fig. 24, this is not a required aspect.

[0137] <Voltage regulator selection device and processing flow> Fig. 25 is a block diagram showing a configuration of a voltage regulator selection device 200 according to this embodiment, and Fig. 26 is a diagram showing a schematic flow of processing in the selection device 200.

[0138] Similar to the selection device 100 of the first embodiment, the selection device 200 is a device that selects a voltage regulator for the purpose of saving energy for consumers who receive power through an individual power distribution system 21, without actually installing the regulator and confirming its effectiveness, and calculates an estimated amount of energy savings that would occur if the selected voltage regulator were installed.

[0139] However, the selection device 200 of this embodiment differs from the selection device 100 of the first embodiment in that the selection device 200 selects a voltage regulator and calculates an estimated energy saving amount based on data for each individual piece of equipment A to D of the customer's equipment 5, which is performed based on data for the entire equipment 5.

[0140] The selection device 200 can be realized by a general-purpose or dedicated computer having the configuration shown in Fig. 2. The selection device 200 includes a data synthesis unit 115 instead of the time-course data acquisition unit 111, and like the selection device 100, includes a power-saving determination index data generation unit 112, an estimated power-saving amount calculation unit 113, and a voltage regulator selection unit 114 as functional components.

[0141] In the selection device 200, first, the data synthesis unit 115 acquires individual power data DPi, which is time-varying data on the power Pi in each of the individual facilities A to D (step S111), and synthesizes (accumulates) the data to generate synthesized power data DC, which is time-varying data on the power P of the facility 5 as a whole (step S112). That is, in this embodiment, the synthesized power data DC is generated as alternative data to the power data DP based on actual measurement at the installation candidate position 6, which is performed in the first embodiment.

[0142] The individual power data DPi may be acquired through the communication unit 105 or the R / W unit 106 from a consumer or other party in advance, or may be acquired by actually measuring the power Pi in each of the individual facilities A to D at a predetermined sampling interval over a certain sampling time (e.g., 24 hours). In the former case, there is an advantage that the operator of the selection device 200 does not need to actually perform the measurements.

[0143] Fig. 27 is a diagram showing individual power data DPi for 24 hours for each of the individual facilities A to D. Fig. 28 is a diagram showing composite power data DC obtained by combining the four individual power data DPi shown in Fig. 27.

[0144] Next, the power saving determination index data generating unit 112 acquires the individual characteristic index data Dαi from the storage unit 104 (step S113). Here, the individual characteristic index data Dαi is data describing the individual characteristic index αi, which is a PV characteristic index specified in advance for each of the individual facilities A to D.

[0145] As described in the first embodiment, the PV characteristics of each of the individual equipment A to D of the equipment 5 are classified into three types, namely, a constant resistance characteristic, a constant current characteristic, and a constant power characteristic, depending on the type of the equipment. Therefore, if the type of the individual equipment A to D is known, it is possible to apply a certain value to the individual characteristic index αi, which is an index indicating the PV characteristics and is essentially calculated in the same way as in formula (1).

[0146] In the present embodiment, an individual characteristic index αi is preliminarily and fixedly determined for each type of individual equipment that may be used by a consumer, and is stored in the storage unit 104. When selecting a voltage regulator, individual characteristic index data Dαi describing the individual characteristic index αi determined for each individual equipment owned by the consumer is acquired from the storage unit 104. Such acquisition may be performed, for example, by an operator of the selection device 200 operating the input unit 102 to select equipment corresponding to the individual equipment A to D from the types of equipment displayed on the display unit 103.

[0147] Note that the actual values ​​of the individual characteristic index αi are not fixed because the actual PV characteristics of the individual equipment A to D may change in real time depending on the operating conditions. Therefore, strictly speaking, the values ​​of the individual characteristic index αi described as fixed values ​​in the individual characteristic index data Dαi are not values ​​that accurately reflect the PV characteristics in any operating conditions of the individual equipment A to D, but it is possible to set values ​​close to the actual values ​​by setting appropriate values ​​according to the type of equipment.

[0148] For example, the individual characteristic index αi of the individual equipment A to D, each of which has individual power data DPi shown in FIG. 27, is specified as follows based on the type of equipment and described in the individual characteristic index data Dαi:

[0149] Individual equipment A: αi=0.5; Individual equipment B: αi=1.5; Individual equipment C:αi=0; Individual equipment D: αi=-0.5.

[0150] After acquiring the individual characteristic index data Dαi containing these values, the power saving determination index data generating unit 112 subsequently generates PV characteristic index data Dα, which is time-dependent data of the PV characteristic index α for the entire equipment 5, based on the individual power data DPi, the individual characteristic index data Dαi, and the composite power data DC (step S114).

[0151] In this embodiment, the PV characteristic index α is generated by the following formula.

[0152] α = Σ{(Pi αi) / P} (10) FIG. 29 is a diagram showing the PV characteristic index data Dα obtained based on the individual power data DPi for the four individual facilities A to D shown in FIG. 27, the individual characteristic index data Dαi described above, and the composite power data DC shown in FIG. 28.

[0153] In this embodiment, as in the first embodiment, the range of -1≦α≦3 is set as the reference range of the PV characteristic index α, and correction is performed if necessary.

[0154] The flow of processing after the PV characteristic index data Dα is obtained is basically the same as in the first embodiment.

[0155] That is, similar to step S103, the power saving determination index data generating unit 112 generates voltage target value data DVt based on the PV characteristic index data Dα and the lower limit value VL and upper limit value VH of the management range of the voltage V described in the voltage management data Dr (step S115).

[0156] When the voltage target value data DVt is obtained, the power saving determination index data generating unit 112 subsequently generates ideal voltage adjustment amount data DVr, similarly to step S104 (step S116).

[0157] However, in this embodiment, when generating the ideal voltage adjustment amount data DVr, the value of the voltage V in the equation (7) is replaced with the standard voltage VS described in the voltage management data Dr.

[0158] That is, Vr = Vt - VS (7α) It is.

[0159] This corresponds to approximating the actual voltage V introduced in equation (7) by the standard voltage V S. In particular, when the deviation of the voltage V from the standard voltage V S is small compared to the control width, the difference between the value of the ideal voltage adjustment amount Vr obtained by equation (7α) and the value of the ideal voltage adjustment amount Vr obtained by equation (7) based on the actual voltage data is also small, and such difference does not significantly affect the selection of the voltage regulator or the calculation of the estimated power saving amount.

[0160] This also means that there is no need to acquire voltage data DV at the installation candidate location 6, which is performed in the first embodiment when selecting a voltage regulator and calculating an estimated power saving amount. As described above, in this embodiment, since the composite power data DC is generated from the individual power data DPi corresponding to each of the individual facilities A to D, the power data DP is not acquired at the installation candidate location 6. Therefore, not acquiring not only the power data DP but also the voltage data DV means that no measurement is required at the installation candidate location 6. This can be said to be a particularly preferable mode for businesses other than consumers, such as energy conservation consultants and power saving consultants.

[0161] Of course, similarly to the first embodiment, the voltage data DV of the facility 5 at the installation candidate location 6 may be acquired and used.

[0162] When the ideal voltage adjustment amount data DVr is obtained, similarly to step S105, the estimated power saving amount calculation unit 113 generates ideal estimated power saving amount data DPs based on the ideal voltage adjustment amount data DVr (step S117).

[0163] In this embodiment, the ideal estimated power saving amount Ps is expressed as follows: Ps = |α Vr| P / VS (8α) The value of the power P at this time is the value described in the composite power data DC.

[0164] Furthermore, the voltage regulator selection unit 114 selects a voltage regulator based on the number of voltage changes in the ideal voltage adjustment amount data DVr in the same manner as in the first embodiment (step S200), and generates selection result data Ds. Note that the conditions for the first and second judgments may be the same as those in the first embodiment.

[0165] Furthermore, the estimated power-saving amount calculation unit 113 generates effective estimated power-saving amount data DPw based on the selection result data Ds (step S300).

[0166] As described above, in this embodiment, as in the first and second embodiments, when a voltage regulator is to be introduced into a low-voltage distribution system to which a consumer's equipment is connected for the purpose of saving energy, it is possible to select a voltage regulator that is suitable for the operating conditions of the consumer's equipment without actually installing a voltage regulator, and to calculate an estimated amount of energy saving that can be expected if the selected voltage regulator is installed.

[0167] In particular, according to this embodiment, if the type of individual equipment owned by a consumer is identified in advance and historical data on power consumption is obtained, it is possible to select a voltage regulator and calculate an estimated amount of energy savings without obtaining power and voltage data at candidate installation locations for the voltage regulator as in the first and second embodiments.

[0168] In other words, compared to the first and second embodiments, it is possible to more easily select a voltage regulator suitable for saving energy by adjusting voltage at the consumer and to judge the effect of energy saving associated with the introduction of the voltage regulator.

[0169] In addition, for example, if the value of the effective estimated power saving amount obtained in this embodiment does not sufficiently indicate the effect of power saving by introducing a voltage regulator, the procedures related to the first and second embodiments may be executed again.

[0170] <Fourth embodiment> In the first to third embodiments described above, the voltage regulator selection unit 114 selects only one voltage regulator based on the ideal voltage adjustment amount data DVr. Alternatively, however, depending on the operating conditions of the equipment 5 (more specifically, depending on the state of voltage changes appearing in the ideal voltage adjustment amount data DVr), a configuration may be adopted in which multiple voltage regulators are selected on the assumption that they will be used in combination.

[0171] In the present embodiment, a case will be described in which a plurality of (specifically, two) voltage regulators are selected from the three types of voltage regulators shown in the first embodiment.

[0172] Fig. 30 is a diagram showing a process flow for selecting a voltage regulator in this embodiment. As shown in Fig. 30, the voltage regulator selection unit 114 first counts the number of voltage changes appearing in the ideal voltage adjustment amount data DVr (step S201) as in the first embodiment, and then performs a first determination for selecting a voltage regulator suitable for installation at the installation candidate position 6 for power saving based on the counted number of voltage changes (step S202).

[0173] The above is similar to the first embodiment, so the details are omitted.

[0174] In addition, if it is determined that the number of voltage changes is 1 or less per day, it is determined that installation of a voltage regulator is unnecessary, and if it is determined that the number of voltage changes is 30 or more per day, a second determination (step S203) is made to select either a high-speed or low-speed semiconductor voltage regulator, and one is selected based on the result, which is similar to the first embodiment, so detailed explanations thereof will be omitted.

[0175] On the other hand, if it is determined that the number of voltage changes is 2 or more and less than 30 times per day, in this embodiment, a second judgment is made to determine whether to select only a mechanical voltage regulator or a combination of a mechanical voltage regulator and a semiconductor voltage regulator as candidates for the voltage regulator to be installed at the candidate installation location 6 (step S204).

[0176] Specifically, the determination is made based on the presence or absence of a voltage change of 5V or more that appears in the ideal voltage adjustment amount data DVr.

[0177] If it is determined that there is no voltage change of 5 V or more in the ideal voltage adjustment amount data DVr, the voltage regulator selection unit 114 selects only mechanical voltage regulators as candidates for the voltage regulator to be installed at the installation candidate position 6.

[0178] On the other hand, if it is determined that the ideal voltage adjustment amount data DVr contains a voltage change of 5 V or more, voltage regulator selection unit 114 selects both a mechanical voltage regulator and a semiconductor voltage regulator as candidates for the voltage regulator to be installed at candidate installation position 6, and then performs a third determination to determine whether a high-speed or low-speed semiconductor voltage regulator should be selected as the candidate based on the presence or absence of a voltage change of 9 V or more that appears in the ideal voltage adjustment amount data DVr (step S205).

[0179] For example, the total number of voltage changes in the ideal voltage adjustment amount data DVr obtained in the second embodiment shown in Fig. 23 is 40 times / day, of which 9 times / day were voltage changes of 9V or more. Therefore, in the case of this embodiment, for facility 5 from which the power data DP and voltage data DV in Fig. 7 and Fig. 8 on which the ideal voltage adjustment amount data DVr is based were obtained, a pair of a mechanical voltage regulator and a semiconductor high-speed voltage regulator is selected as candidates for the voltage regulator to be installed at candidate installation location 6.

[0180] When multiple voltage regulators are selected depending on the operation status of the equipment as in this embodiment, it becomes possible to perform power saving at the consumer's facility in a more detailed manner depending on the operation status of the equipment.

[0181] However, how the multiple voltage regulators selected and installed at candidate installation locations 6 actually operate will differ depending on the operating conditions of facility 5 and the type of selected voltage regulator.

[0182] Therefore, it is not possible to definitively determine the effective estimated power savings when multiple voltage regulators are installed. However, by taking the power loss Pls in equation (9) as the sum of the power losses in the selected voltage regulators, it is possible to estimate the minimum value from equation (9).

[0183] <Modification> For customer equipment 5 provided in power system 10 shown in the first embodiment, a voltage regulator may be selected in the manner shown in the third embodiment and an estimated power saving amount may be calculated, or for customer equipment 5 provided in power system 20 shown in the third embodiment, a voltage regulator may be selected in the manner shown in the first embodiment and an estimated power saving amount may be calculated.

[0184] In the first and second embodiments, the time-course data acquisition unit 111 of the voltage regulator selection device 100 acquires power data DP and voltage data DV, which are time-course data on power P and voltage V, and these power data DP and voltage data DV are used in subsequent processing. Alternatively, however, the time-course data acquisition unit 111 may acquire time-course data on current I (current data) instead of the power data DP, and generate the power data DP by calculating power P from the current value described in the current data and the voltage value described in the voltage data DV.

[0185] The PV characteristic index α may be calculated from the voltage V and the current I.

[0186] Furthermore, in the first and second embodiments, the sampling time is 24 hours and the sampling interval is 1 second, but the sampling interval may be 10 ms and the sampling time may be 12 hours. In this case, it becomes possible to select an appropriate voltage regulator based on information on the adjustment speed (adjustment time) of the voltage regulator.

[0187] In the first to fourth embodiments described above, three types of voltage regulators are set as candidates for selection, but other types of voltage regulators may be set as candidates. Also, in the fourth embodiment, a maximum of two voltage regulators are selected, but three or more voltage regulators may be selected. In any case, appropriate selection conditions are set according to the characteristics of the candidate voltage regulators, and a determination is made based on the set conditions, whereby one or more voltage regulators are selected according to the operating status of the facility 5 at the consumer.

Claims

1. An apparatus for selecting a voltage regulator for power saving at a power consumer having electrical equipment connected to a low-voltage distribution system, comprising: a power saving determination index data generating unit that generates power saving determination index data serving as a determination index when selecting the voltage regulator, based on time-series data of power and voltage at a candidate installation position of the voltage regulator on the low-voltage distribution system or alternative data to the time-series data; a voltage regulator selection unit that selects one or more voltage regulators from a plurality of predetermined candidate voltage regulators based on the power saving determination index data; A voltage regulator selection device comprising:

2. 2. The voltage regulator selection device according to claim 1, an estimated power-saving amount calculation unit that generates ideal estimated power-saving amount data, which is time-dependent data on an ideal estimated power-saving amount when the one or more voltage regulators are installed at the installation candidate positions, based on the power-saving determination index data; The voltage regulator selection device further comprising:

3. 3. The voltage regulator selection device according to claim 2, the estimated power-saving amount calculation unit further generates effective estimated power-saving amount data, which is time-dependent data of an effective estimated power-saving amount obtained by subtracting a power loss in the one or more voltage regulators from the ideal estimated power-saving amount; A voltage regulator selection device comprising:

4. 3. The voltage regulator selection device according to claim 1, further comprising: The power saving determination index data generation unit generating PV characteristic index data, which is time-series data of a ratio of a power change per unit power to a voltage change per unit voltage at the installation candidate position, based on the time-series data or the alternative data; generating voltage target value data, which is time-lapse data of voltage values ​​at the candidate installation positions when the power consumption of the equipment is minimized while maintaining the operating status of the equipment substantially the same as when the time-lapse data is obtained, based on the P-V characteristic index data and a management range of voltage in the low-voltage distribution system; generating, based on the voltage target value data, ideal voltage adjustment amount data which is time-lapse data of an adjustment amount from an actual voltage value at the installation candidate position when the equipment is operated in accordance with the voltage target value data while maintaining the operating status of the equipment substantially the same as when the time-lapse data is obtained; the voltage regulator selection unit selects the one or more voltage regulators based on the ideal voltage regulation amount data. A voltage regulator selection device comprising:

5. 5. The voltage regulator selection device according to claim 4, The power saving determination index data generation unit In the time-series data of power and voltage at the installation candidate position, a power value and a voltage value measured at an arbitrary timing are respectively designated as P and V, and a power value and a voltage value measured immediately before the arbitrary timing are respectively designated as P0 and V0. α=(1-P / P0) / (1-V / V0) The time-dependent data of the P-V characteristic index α obtained by the following formula is generated as the P-V characteristic index data, generating the ideal voltage adjustment amount data based on the voltage target value data and the time-dependent data of the voltage at the installation candidate position; A voltage regulator selection device comprising:

6. 6. The voltage regulator selection device according to claim 5, The power saving determination index data generation unit calculating the P-V characteristic index α only for a timing at which a difference value between V and V0 in the time-dependent data of the voltage at the installation candidate position is equal to or greater than a predetermined reference value; For a timing at which the difference value does not exceed the reference value, the value of the P-V characteristic index α is set to be the same as the value at the immediately preceding timing. A voltage regulator selection device comprising:

7. 5. The voltage regulator selection device according to claim 4, The power saving determination index data generation unit generating composite power data that is the substitute data for the power time-series data at the installation candidate location by synthesizing the power time-series data of individual pieces of equipment included in the equipment; generating the PV characteristic index data based on the composite power data, time-dependent data of power in the individual equipment, and an index value of power-voltage characteristics for the individual equipment, the index value being fixed in advance according to the type of the individual equipment; A voltage regulator selection device comprising:

8. 5. The voltage regulator selection device according to claim 4, the candidate voltage regulators are a mechanical voltage regulator, a semiconductor low-speed voltage regulator, and a semiconductor high-speed voltage regulator; the voltage regulator selection unit selects the one or more voltage regulators based on a number of voltage changes in the ideal voltage adjustment amount data and whether or not a voltage change equal to or greater than a predetermined value exists in the ideal voltage adjustment amount data. A voltage regulator selection device comprising:

9. An apparatus for selecting a voltage regulator for power saving at a power consumer having electrical equipment connected to a low-voltage distribution system, the apparatus comprising: a power saving determination index data generating unit that generates power saving determination index data serving as a determination index when selecting the voltage regulator, based on time-series data of power and voltage at a candidate installation position of the voltage regulator on the low-voltage distribution system or alternative data to the time-series data; a voltage regulator selection unit that selects one or more voltage regulators from a plurality of predetermined candidate voltage regulators based on the power saving determination index data; A voltage regulator selection device comprising: A voltage regulator selection program comprising:

10. A method for selecting a voltage regulator for power saving at an electric power consumer having an electric equipment connected to a low-voltage distribution system, comprising the steps of: a power saving determination index data generating step of generating power saving determination index data serving as a determination index for selecting the voltage regulator based on time-series data of power and voltage at a candidate installation position of the voltage regulator on the low-voltage distribution system or alternative data to the time-series data; a voltage regulator selection step of selecting one or more voltage regulators from a plurality of predetermined candidate voltage regulators based on the power saving determination index data; A voltage regulator selection method comprising:

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