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 a power consumer having electric equipment connected to a low-voltage power distribution system is configured to comprise: a power-saving determination index data generation unit for generating power-saving determination index data serving as a determination index in selection of a voltage regulator on the basis of time series data pertaining to power and voltage at an installation candidate position for a voltage regulator on the low-voltage power distribution system, or on the basis of alternative data; and a voltage regulator selection unit for selecting one or more voltage regulators from among a plurality of predetermined candidate voltage regulators on the basis of the power-saving determination index data.

Description

Voltage regulator selection device, voltage regulator selection program, and voltage regulator selection method

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

[0002] From the viewpoint of energy conservation, there is a demand for power saving in low-voltage power distribution systems that are connected to high-voltage power distribution systems (commercial power sources) 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 a consumer connected to the high-voltage power distribution system (for example, in a distribution board to which individual appliances are connected).

[0003] An automatic voltage control device is already known that converts an input voltage to 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 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 greatest power savings for each customer's facility depends on the connection and operating conditions.

[0005] However, in the past, the required voltage regulation 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 without actually installing the voltage regulator, 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 costs and construction costs. Alternatively, a voltage regulator with inappropriate capabilities was installed, which could result in no power-saving effect being achieved.

[0006] One approach would be to temporarily install a potential voltage regulator and then check and examine its power-saving effects, but this would require time, money, and effort.

[0007] Patent No. 4249578

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a method that enables a voltage regulator suitable for power saving at a consumer to be selected without installing it, and that enables an estimation of the power saving effect when the selected voltage regulator is installed in a power distribution system.

[0009] In order to solve the above problem, 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, characterized in that it comprises: a power saving judgment index data generation unit that generates power saving judgment index data that serves 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 plurality of predetermined 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, characterized in that it further comprises an estimated power saving amount calculation unit that generates ideal estimated power saving amount data, which is time-lapse data of the 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-lapse data of 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 P-V characteristic index data, which is time-varying 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-varying data or the alternative data; generates voltage target value data, which is time-varying data of a voltage value at the candidate installation location when power consumption of the equipment is minimized while maintaining an operating status of the equipment substantially the same as when the time-varying data is obtained, based on the P-V 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-varying data of an adjustment amount from an actual value of a voltage value at the candidate installation location when the equipment is operated in accordance with the voltage target value data while maintaining an operating status of the equipment substantially the same as when the time-varying 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 P-V characteristic index data, time-lapse data of a P-V characteristic index α obtained by the formula α=(1−P / P0) / (1−V / V0), where P and V are the power and voltage values ​​measured at an arbitrary timing in the time-lapse data of power and voltage at the candidate installation location, respectively, and P0 and V0 are the power and voltage values ​​measured immediately before the arbitrary timing, and generates the ideal voltage adjustment amount data based on the voltage target value data and the time-lapse data of the voltage at the candidate installation location.

[0014] A sixth aspect of the present invention is the voltage regulator selection device according to the fifth aspect, wherein the power saving determination index data generation unit calculates the P-V characteristic index α only for timings at which the difference value between V and V0 in the time-lapse data of the voltage at the candidate installation location was equal to or greater than a predetermined reference value, and for timings at which the difference value does not exceed the reference value, the value of the P-V characteristic index α is set to 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 history data at the candidate installation location, by synthesizing power history data for individual facilities included in the facility, and generates the P-V characteristic index data based on the composite power data, the power history data for the individual facilities, and an index value of the power-voltage characteristic for the individual facilities, which is fixedly determined in advance depending on the type of the individual facilities.

[0016] An eighth aspect of the present invention is the 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 the ideal voltage adjustment amount data has a voltage change equal to or greater than a predetermined value.

[0017] A ninth aspect of the present invention is a voltage regulator selection program that, 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 comprising: a power saving determination index data generation unit that generates power saving determination index data that serves as a determination 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 plurality of predetermined candidate voltage regulators based on the power saving determination 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, characterized in that it comprises: a power saving judgment index data generation step for generating power saving judgment index data that serves 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 for selecting one or more voltage regulators from a plurality of predetermined 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 power 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 determine the effect of power saving associated with the introduction of a voltage regulator.

[0021] 1 is a diagram schematically illustrating the configuration of a power system 10. FIG. 2 is a block diagram illustrating the configuration of a voltage regulator selection device 100. FIG. 3 is a diagram illustrating functional components virtually provided in the voltage regulator selection device 100, together with the flow of data processed in the voltage regulator selection device 100. FIG. 4 is a diagram illustrating a general flow of processing in the voltage regulator selection device 100. FIG. 5 is a diagram illustrating a process flow related to generation of power saving determination index data. FIG. 6 is a diagram illustrating a process flow related to selection of a voltage regulator. FIG. 7 is a diagram illustrating power data DP. FIG. 8 is a diagram illustrating voltage data DV. FIG. 9 is a diagram illustrating P-V characteristic index data Dα in a first embodiment. FIG. 10 is a diagram illustrating corrected P-V characteristic index data Dα. FIG. 11 is a partial enlarged view of a part of a time range of the corrected P-V characteristic index data Dα. FIG. 12 is a partial enlarged view of voltage target value data DVt in the first embodiment. FIG. 13 is a partial enlarged view of ideal voltage adjustment amount data DVr in the first embodiment. FIG. 14 is a partial enlarged view of ideal estimated power saving amount data DPs in the first embodiment. 1 is a diagram showing a graph of power data DP and a graph of ideal power-saving power data DP0 in the first embodiment together. A diagram showing the amount of change in the ideal voltage adjustment amount Vr in the first embodiment. A diagram showing a graph of effective power-saving power data DP1 in the first embodiment together with a graph of power data DP. A diagram illustrating P-V characteristic index data Dα in the second embodiment. A partially enlarged partial view of a partial time range of the P-V characteristic index data Dα in the second embodiment. A partially enlarged partial view of ideal voltage adjustment amount data DVr in the second embodiment. A partially enlarged partial view of ideal estimated power-saving amount data DPs in the second embodiment. A diagram showing a graph of power data DP and a graph of ideal power-saving power data DP0 in the second embodiment together. A diagram showing the amount of change in the ideal voltage adjustment amount Vr in the second embodiment. A schematic diagram of the configuration of a power system 20. A block diagram of the configuration of a voltage regulator selection device 200. A diagram showing a general flow of processing in the voltage regulator selection device 200. It is a diagram showing individual power data DPi of each of the individual facilities A to D. It is a diagram showing composite power data DC. It is a diagram showing PV characteristic index data Dα in the third embodiment.FIG. 13 is a diagram showing a process flow relating to the selection of a voltage regulator in the fourth embodiment.

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

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

[0024] <Outline of Power System> FIG. 1 is a diagram schematically illustrating the configuration of a power system 10 including electrical equipment of a customer to 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 power to a large number of consumers (more specifically, the electrical equipment owned by each consumer; the same applies hereinafter) using a high-voltage power distribution system 1 and a low-voltage power distribution system 2 connected thereto. 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.

[0026] 1, the low-voltage distribution system 2 branches into five individual distribution systems 2a, 2b, 2c, 2d, and 2e corresponding to individual consumers, and each is provided with a distribution board 4 (4a, 4b, 4c, 4d, and 4e). Electrical equipment owned by each consumer is connected to each distribution board 4 as appropriate. 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 management range that includes a predetermined standard voltage. This is also true 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, with the management range in the former case being 95 V to 107 V and in the latter case being 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 energy, without actually installing and verifying the effectiveness, for a consumer who receives power from a certain individual power distribution system 2a connected to the high-voltage power distribution system 1 in the above-described manner. Figure 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. Hereinafter, these four individual facilities A to D will be collectively referred to simply as facility 5.

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

[0030] Generally speaking, the facilities 5 (individual facilities A to D) owned by the customer operate as a whole within the above-mentioned control range according to the power-voltage characteristics (hereinafter referred to as P-V characteristics) that correspond 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 power is selected, including whether installation is necessary, based on the power and voltage values ​​at the candidate installation location 6. Note that, for ease of explanation, the term "selection of a voltage regulator" may be used hereinafter, even when it is determined that installation is unnecessary. Furthermore, based on past actual power and voltage values, an estimated amount of power saving is also calculated assuming that the selected voltage regulator was used during operation of the equipment when those actual values ​​were obtained.

[0032] <Voltage Regulator Selection Device> Figure 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 for a consumer supplied with power through a certain individual power distribution system 2a, without actually installing the voltage regulator and confirming the effect, and calculates an estimated amount of power savings 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 Figure 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 unit of the selection device 100; an input unit 102 including input devices such as a keyboard, mouse, or 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 details 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, processing results, etc.; a communication unit 105 including a communication device for wired or wireless communication with the outside via the Internet, an intranet, etc.; 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, or external hard disk.

[0033] In the voltage regulator selection device 100, a predetermined operating program stored in the ROM 101b, RAM 101c or 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 selection device 100 according to this embodiment, together with the flow of data processed in selection device 100.

[0035] The selection device 100 includes, as functional components, a time-series 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-series data acquisition unit 111 acquires power data DP and voltage data DV, which are time-series data (data showing changes over time) of power P and voltage V, respectively, at the candidate installation location 6 of the voltage regulator in the power system 10 described above.

[0037] The power saving determination index data generator 112 sequentially generates data (power saving determination index data) required for selecting a voltage regulator and calculating an estimated amount of power saving, based on the power data DP and voltage data DV acquired by the time-series data acquirer 111 and the voltage management data Dr that has been input in advance and stored in the storage unit 104. Here, the voltage management data Dr is data including the standard voltage VS in the low-voltage distribution system 2, and the lower limit VL and 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. Details of these data will be described later.

[0039] The estimated power saving amount calculation unit 113 generates time data of the amount of power saving that is estimated to have been possible if power saving had been implemented in the consumer's equipment 5 at the time the power data DP and 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-varying data of the 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-varying data of the effective estimated power-saving amount Pw, which is the estimated power-saving amount taking into account the 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 by the power saving determination index data generation unit 112, and generates selection result data Ds that describes 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 content of the ideal voltage adjustment amount data DVr, the voltage regulator selection unit 114 may determine that selection of a voltage regulator is not necessary. Hereinafter, this will be referred to as selection of a voltage regulator.

[0043] <Processing Flow> Next, a specific example will be described of the processing related to the selection of a voltage regulator and the calculation of an estimated amount of power saving, which is performed by the selection device 100 having the above-described configuration. In the following, it is assumed that the standard voltage VS is 202 V, the lower limit value VL of the control range is 180 V, and the upper limit value VH is 220 V.

[0044] 4 is a diagram showing a general 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 operation of the input unit 102, various pieces of power saving determination index data are first generated sequentially (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 the flow of processing related to the generation of power saving determination index data, and Fig. 6 is a diagram showing the flow of processing related to the selection of a voltage regulator.

[0046] (Generation of power saving determination index data) As shown in Figure 5, when generating 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 the actual values ​​of power P and voltage V in the consumer's equipment 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] Although there is no particular limit to the sampling time, 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 set appropriately within the range of several milliseconds to several minutes, taking into consideration the operating status of the equipment 5, the measurement time, etc.

[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-dependent data acquiring unit 111 acquires the power data DP and the voltage data DV, the power saving determination index data generating unit 112 then generates the PV characteristic index data Dα (step S102).

[0051] The PV characteristic index data Dα is time-series data of the PV characteristic index α, which is an index that characterizes the PV characteristics of the facility 5 used by the customer.

[0052] In this embodiment, the P-V 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 P-V characteristic index α is defined by the following equation: α=(1-P / P0) / (1-V / V0) (1)

[0053] The PV characteristic index α is a value that changes from moment to moment in response to changes in the PV characteristics that accompany 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 P-V characteristic index data Dα, which is time-series data of the P-V characteristic index α, by sequentially performing the calculation of equation (1) based on the power data DP and the voltage data DV over the entire measurement time of the power and voltage. Fig. 9 is a diagram illustrating the P-V 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 depending on the type of facility: constant resistance characteristics, constant current characteristics, and constant power characteristics. Therefore, the PV characteristic index α is a value that corresponds to the combination of the PV characteristics of the individual facilities in operation among the facility 5.

[0056] For example, in an individual facility where the P-V characteristic is a constant resistance characteristic, if the impedance is Z, the relationship between the power value P and the voltage value V is P = V ２ / Z (2) Similarly, the relationship between the power value P0 and the voltage value V0 is expressed as follows: P0=(V0) ２ / Z ... (2α) When these equations are substituted into equation (1), unless V = V0, α = (1 - V ２ / (V0) ２) / (1-V / V0) = 1+V / V0 (3) However, since the voltage values ​​V and V0 are both within the control range, in equation (3) V / V0 = 0.8 to 1.2 at most. Therefore, from equation (3), it can be said that α is approximately 2.

[0057] Furthermore, in individual equipment whose P-V characteristics are constant current characteristics, if the current value is I, then the following relationship holds between the power value P and the voltage value V: P = V.I (4) Similarly, the following relationship holds between the power value P0 and the voltage value V0: P0 = V0.I (4α) Substituting these equations into equation (1), we obtain: α = (1 - V.I / V0.I) / (1 - V / V0) = 1 (5)

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

[0059] Therefore, the P-V characteristic index α is generally a value of approximately 0 to 2. However, the actual P-V characteristic of the equipment 5 may take a value outside this range due to factors such as losses in the internal components of each of the individual equipment A to D. For example, if V > V0 and P < P0, α will be a negative value. Hereinafter, if the P-V characteristic index α is a value that satisfies the range of -1≦α≦3, it will be considered to reflect the actual P-V characteristic, and this range will be 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 equation (1), the calculation result of the P-V 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 P-V characteristic index data Dα shown in FIG. 9 , the P-V characteristic index α also fluctuates up to about ±1000.

[0061] When such a calculation result is obtained, the power saving determination index data generation unit 112 sets the average of the calculation values ​​for the preceding and following sampling timings as the value of the P-V characteristic index α at that sampling timing. This takes into consideration the fact that a value of the P-V characteristic index α that exceeds the reference range cannot be said to accurately represent the P-V characteristics at the sampling timing at which that value was obtained. Using such a value as is is not desirable because it may result in inappropriate selection of a voltage regulator or calculation of an estimated amount of power saving. As a result, the P-V characteristic index α will be a value within the reference range of -1≦α≦3.

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

[0063] Fig. 10 is a diagram illustrating the P-V characteristic index data Dα after the P-V characteristic index data Dα shown in Fig. 9 has been corrected in this manner. Fig. 11 is a partially enlarged view of a part of the time range (from 2:00 PM to 2:10 PM) of the P-V characteristic index data Dα after the correction shown in Fig. 10. Note that, hereinafter, unless otherwise specified, it is assumed that the above-described correction has been performed on the P-V characteristic index data Dα when there is a value of the P-V characteristic index α that exceeds the reference range.

[0064] Once the P-V characteristic index data Dα is obtained in this manner, the power saving determination index data generator 112 then generates voltage target value data DVt. The voltage target value data DVt is time-series data of the voltage target value Vt, which is the voltage value that should be set when minimizing (maximizing) power consumption while maintaining substantially the same operating conditions in the consumer facility 5 that was actually operating by applying the voltage value recorded in the voltage data DV.

[0065] In other words, if the customer's equipment 5 had been operated completely in accordance with the voltage target value data DVt, the equipment 5 would have operated in the same way 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 generation unit 112 generates voltage target value data DVt based on the P-V 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 S103).

[0067] Specifically, the power saving determination index data generating unit 112 sets Vt=VL for sampling timings where 0<α≦3, and sets Vt=VH for sampling timings 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 P-V characteristic, so the power P is minimum when the voltage V is at the lower limit value VL within the control range, and when -1≦α≦0, the power P has a monotonically decreasing relationship with the voltage V in the P-V characteristic, so the power P is minimum when the voltage V is at the upper limit value Vh within the control range.

[0069] Strictly speaking, in the case of a constant resistance characteristic, for example, the P-V characteristic may change like an nth order function (curvilinearly), and the power P may be minimized at a voltage V other than the upper or lower limits of the control range. However, it is difficult to identify the actual P-V characteristic, which may change from moment to moment, at each sampling timing, and in fact, in most cases the P-V characteristic changes monotonically (linearly). In light of the objective 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 target voltage value Vt as described above.

[0070] The power saving determination index data generating unit 112 generates the voltage target value data DVt by specifying 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, covering the same time range as FIG.

[0072] Once the voltage target value data DVt is obtained in this manner, the power saving determination index data generator 112 then 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, when the consumer's equipment 5, which 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 use 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 calculated by the following equation: Vr=Vt-V (7)

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

[0076] 13 is a partially enlarged view of the ideal voltage adjustment amount data DVr generated by the power saving determination index data generation unit 112 by performing calculations according to equation (7) using 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] Once 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 by the estimated power-saving amount calculation unit 113 to generate ideal estimated power-saving amount data DPs (step S105). Note that the order in which the voltage regulator selection is performed and the ideal estimated power-saving amount data DPs is generated does not matter.

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

[0079] The ideal estimated power saving amount Ps and ideal voltage adjustment amount Vr at a certain sampling timing, and the power P and voltage V at that sampling timing, are related by the following relationship when the P-V characteristic index α is used: Ps / |Vr|=|α|·P / V.

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

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

[0082] Fig. 14 is a partially enlarged view of the ideal estimated power-saving amount data DPs, generated by the estimated power-saving amount calculation unit 113 using the P-V characteristic index data Dα shown in Fig. 10, the ideal voltage adjustment amount data DVr partially 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 also shows a graph of the power data DP over the same time range as Fig. 14, together with a graph of ideal power-saving power data DP0, which is data on the difference between the power P and the ideal estimated power-saving amount Ps. The ideal power-saving power data DP0 corresponds to time-dependent data on 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 equation (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 operating at 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 next.

[0085] (Selection of Voltage Regulator) Next, the selection of a voltage regulator suitable for installation at the candidate installation 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, and semiconductor voltage regulators are further classified into high-speed and low-speed types. In this embodiment, these mechanical voltage regulators, low-speed semiconductor voltage regulators, and high-speed semiconductor voltage regulators are selected as candidates 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 2 V / tap and ±2 taps, 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] It is also 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 times the voltage is adjusted, and the amount of power loss Pls during voltage adjustment is 1% of the power P. An example of such a low-speed semiconductor voltage regulator is an SVG (Static Var Generator).

[0090] These three types of voltage regulators differ primarily in the number of voltage adjustments (per day) and the voltage adjustment speed (adjustment time). Taking this into consideration, in this embodiment, a voltage regulator is selected based essentially 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. Therefore, the voltage regulator to be installed at the candidate installation location 6 must be one that is judged to be able to actually adjust 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 (number of voltage changes) that the change (difference value) between the value of the ideal voltage adjustment amount Vr at a certain sampling timing and the value of the ideal voltage adjustment amount Vr at the immediately preceding sampling timing is ±2 V 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 over the time range shown in Fig. 13. The number of times a change of ±2 V or more occurs in such a profile of the difference value is counted by the voltage regulator selection unit 114. To be clear, there are several peaks in the ideal voltage adjustment amount Vr in Fig. 13, and 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 rise to these peaks is counted.

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

[0094] First, if 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 or more times per day but 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 location 6.

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

[0097] If it is determined that the ideal voltage adjustment amount data DVr contains 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 location 6.

[0098] On the other hand, if it is determined that there is no voltage change of 9 V or more in the ideal voltage adjustment amount data DVr, 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 location 6.

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

[0100] The total number of voltage changes in the ideal voltage adjustment amount data DVr, the partial enlargement of which is shown in Figure 13, is 3,988 times per day, of which 3,957 times per day were voltage changes of 9 V or more. Therefore, for facility 5 from which the power data DP and voltage data DV of Figures 7 and 8, which are the basis of the ideal voltage adjustment amount data DVr, were obtained, a semiconductor-type high-speed voltage regulator will be 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 merely obtained from the past power data DP and voltage data DV, it can also be said that if the consumer's facility 5 operates in the future in the same manner as when the power data DP and voltage data DV were obtained, the same degree of power saving will be possible 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 candidate installation location 6.

[0103] (Calculation of Effective Estimated Power Savings) However, as described above, depending on the selected voltage regulator, when it is actually installed and used at the candidate installation location 6, a power loss may occur at a predetermined 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 also take such 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 based on the description content and the previously generated ideal estimated power saving data DPs, performs the following calculation over the entire sampling time to generate effective estimated power saving data DPw, which is time-lapse 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 saving is actually achieved.

[0107] Fig. 17 shows 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 ideal power-saving power data DP0 shown in Fig. 15. As described above, for the equipment 5 from which the power data DP and voltage data DV of Figs. 7 and 8 were obtained, a semiconductor-type high-speed voltage regulator is selected as a candidate for the voltage regulator to be installed, and therefore the power loss amount Pls used to obtain 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 locations indicated by arrows AR, the effective power-saving power data DP1 is greater than the ideal power-saving power data DP0. Therefore, in such locations, even if the voltage regulator adjusts the voltage in accordance with the ideal voltage adjustment amount data DVr, no power saving effect can actually be 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 compared to the power data DP, so if the equipment 5 operates in the same way as when the power data DP was obtained, it is determined that sufficient energy-saving effects can be expected if the semiconductor-type high-speed voltage regulator selected as a candidate is installed at the candidate installation location 6.

[0110] Furthermore, as mentioned above, even when a mechanical voltage regulator is selected, it is necessary to take into consideration the power loss Pls of 1% of the power P, but when a semiconductor slow-speed voltage regulator is selected, it is not necessary to take into consideration the power loss.

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

[0112] As explained 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 the voltage regulator, and it is also possible to calculate the estimated amount of energy savings 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 through voltage adjustment at the consumer and to determine the power saving effect of introducing the voltage regulator, without actually installing the voltage regulator, thereby preventing 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 first embodiment described above, the P-V characteristic index α is calculated for all sampling times of the power data DP and voltage data DV acquired by the time-dependent data acquisition unit 111, and the P-V characteristic index data Dα is generated.

[0115] However, as described above, when calculating the actual P-V characteristic index α, errors in reading the power and voltage values ​​may occur, causing the calculation result of the P-V characteristic index α for the sampling timing to fall outside the above-mentioned reference range. In the first embodiment, this was corrected based on the reference range of -1≦α≦3. However, even with this correction, minute cycle fluctuations remained, so the number of voltage adjustments in the ideal voltage adjustment amount data DVr was much greater than the number of times used as the judgment criterion (maximum of 30 times per day). In consideration of the sampling time, it may be more appropriate to consider most of the voltage changes as being due to noise occurring in the power data DP and 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 P-V characteristic index α is limited, and the effects of noise occurring in the power data DP and the voltage data DV are eliminated, thereby enabling more efficient selection of a voltage regulator and calculation of an estimated amount of power savings. However, since the configuration of the voltage regulator selection device 100 in this embodiment can be the same as in the first embodiment, and the processing flow is also generally 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 P-V characteristic index data Dα based on the power data DP and voltage data DV acquired by the time-series data acquisition unit 111 (step S102), the power saving determination index data generation unit 112 calculates the P-V characteristic index α based on equation (1) only for sampling times where the V-V0 value exceeds 0.9%. The value of the P-V characteristic index α for sampling times where the V-V0 value does not exceed 0.9% is set to the same as the value for the immediately preceding sampling time. However, the reference value of 0.9% is merely an example, and other values ​​may be set.

[0118] Fig. 18 is a diagram illustrating P-V 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. Fig. 19 is a partial enlarged view of a part of the time range (from 2:00 PM to 2:10 PM) of the P-V characteristic index data Dα shown in Fig. 18.

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

[0120] The subsequent processing is basically the same as in the first embodiment. That is, the power saving determination index data generator 112 generates voltage target value data DVt based on the P-V characteristic index data Dα shown in Fig. 18, and further generates ideal voltage adjustment amount data DVr by performing the calculation of equation (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, covering 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 calculating 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 P-V 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, covering the same time range as Fig. 19. Fig. 22 is a view showing a graph of the power data DP over the same time range as Fig. 19, together with a graph of ideal saved power data DP2, which is data on the difference between the power P and the ideal estimated power-saving amount Ps.

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

[0123] On the other hand, according to Figures 21 and 22, even when calculating the ideal estimated power saving amount 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 power saving, 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 on which the P-V characteristic index data Dα is based are eliminated at the time of generation. 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 reliable as a value of the amount of power saving 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] 23 is a diagram showing the amount of change in the value of the ideal voltage adjustment amount Vr at a certain sampling timing with respect to the value of 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 small cycle fluctuations are observed in FIG. 23, most of the amount of change is kept below 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 per day, of which 9 times per day were voltage changes of 9 V or more. Therefore, in this embodiment as well, for facility 5 for which the power data DP and voltage data DV in Figures 7 and 8 were obtained, a semiconductor-type high-speed voltage regulator will be selected as a candidate for the voltage regulator to be installed at candidate installation 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 that is suitable for the operating conditions of the consumer's equipment without actually installing a voltage regulator, and to calculate the estimated amount of energy savings that can be expected if the selected voltage regulator is installed.

[0130] In other words, it is possible to select a voltage regulator suitable for saving power through voltage adjustment at the consumer and to determine the power saving effect that comes with introducing the voltage regulator, without actually installing the voltage regulator.

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

[0132] Like the first embodiment, this embodiment is also expected to be implemented by consumers themselves, and also 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 Power System> FIG. 24 is a diagram schematically illustrating the configuration of a power system 20 including customer facility 5 that is a target for introducing a voltage regulator according to the third embodiment of the present invention.

[0134] 1, the power system 20 is a system that transmits and distributes power to a large number of consumers using 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, which are facilities 5 owned by one consumer, are connected directly in parallel to the individual distribution system 21 without going through a distribution board 4. Furthermore, 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 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 the configuration of a voltage regulator selection device 200 according to this embodiment. Fig. 26 is a diagram showing a schematic flow of processing in selection device 200.

[0138] Similar to the selection device 100 according to 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 electricity from an individual power distribution system 21, without actually installing the regulator and verifying its effectiveness, and calculates an estimated amount of energy that would be saved 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, which selects a voltage regulator and calculates an estimated amount of energy saving based on data for each individual piece of equipment A to D of the equipment 5 owned by the consumer, in that the selection device 200 selects a voltage regulator and calculates an estimated amount of energy saving 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 historical data acquisition unit 111, and similarly to the selection device 100, includes, as functional components, a power-saving determination index data generation unit 112, an estimated power-saving amount calculation unit 113, and a voltage regulator selection unit 114.

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

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

[0143] Fig. 27 is a diagram showing 24 hours of individual power data DPi 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 generation 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 that describes the individual characteristic index αi, which is a PV characteristic index that is specified in advance for each of the individual facilities A to D.

[0145] As explained in the first embodiment, the P-V characteristics of each of the individual facilities A to D of the facility 5 are classified into three types depending on the type: constant resistance characteristics, constant current characteristics, and constant power characteristics. Therefore, if the type of the individual facilities A to D is known, it is possible to apply a specific value to the individual characteristic index αi, which is an index indicating the P-V characteristics and is essentially calculated in the same way as in equation (1).

[0146] In the present embodiment, it is assumed that an individual characteristic index αi is previously fixedly determined for each type of individual equipment that may be used by a consumer and stored in the storage unit 104. Then, when selecting a voltage regulator, it is assumed that 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 and selecting equipment corresponding to 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 P-V characteristics of the individual equipment A to D can 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 P-V characteristics of the individual equipment A to D in any operating condition, but by setting an appropriate value according to the type of equipment, it is possible to set a value close to the actual value.

[0148] For example, the individual characteristic index αi of the individual equipment A to D, each of whose individual power data DPi is shown in Figure 27, is identified 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 that describes these values, the power saving determination index data generation unit 112 then generates P-V characteristic index data Dα, which is time-lapse data of the P-V 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 equation.

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

[0153] In this embodiment, as in the first embodiment, the range of -1≦α≦3 is set as the reference range for 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, the power saving determination index data generation unit 112 generates the voltage target value data DVt based on the P-V 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, as in step S103 (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, similar 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 equation (7) is substituted with the standard voltage VS described in the voltage management data Dr.

[0158] That is, Vr=Vt-VS (7α).

[0159] This corresponds to approximating the actual voltage V introduced into equation (7) by the standard voltage VS. In particular, when the deviation of the voltage V from the standard voltage VS 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 a 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 candidate installation location 6, which is performed in the first embodiment when selecting a voltage regulator and calculating an estimated amount of power saving. As described above, in this embodiment, the composite power data DC is generated from the individual power data DPi corresponding to each of the individual facilities A to D, so the power data DP is not acquired at the candidate installation location 6. Therefore, not acquiring not only the power data DP but also the voltage data DV means that measurements at the candidate installation location 6 are unnecessary. 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 equipment 5 at the candidate installation location 6 may be acquired and used.

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

[0163] In this embodiment, the ideal estimated power saving amount Ps is calculated 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 (step S200) in the same manner as in the first embodiment, and generates selection result data Ds. Note that the conditions for the first and second determinations 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 the voltage regulator, and to calculate the estimated amount of energy savings 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 the 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 power savings without having to obtain data on power and voltage values ​​at candidate locations for installing the voltage regulator as in the first and second embodiments.

[0168] In other words, compared to the first and second embodiments, it is easier to select a voltage regulator suitable for saving power through voltage adjustment at the consumer and to determine the power saving effect that comes with introducing 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 power saving effect of 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. However, instead of this, depending on the operating status 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 this 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] 30 is a diagram showing the flow of processing related to the selection of a voltage regulator performed in this embodiment. As shown in Fig. 30, the voltage regulator selector 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 primary determination based on the counted number of voltage changes to select a voltage regulator suitable for installation at the candidate installation location 6 for the purpose of saving power (step S202).

[0173] The above is the same as in the first embodiment, so the details will be omitted.

[0174] Furthermore, if it is determined that the number of voltage changes is once 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 also the same as in 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 times per day but less than 30 times per day, in this embodiment, a second determination 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 installation candidate location 6 (step S204).

[0176] Specifically, the determination is made based on whether or not there is a voltage change of 5V or more that appears in the ideal voltage adjustment amount data DVr.

[0177] If it is determined that the ideal voltage adjustment amount data DVr does not contain a voltage change of 5 V or more, 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, the voltage regulator selection unit 114 selects both a mechanical voltage regulator and a semiconductor voltage regulator as candidates for voltage regulators to be installed at the installation candidate position 6, and then performs a third determination to determine whether to select a high-speed or low-speed semiconductor voltage regulator 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 per day, of which 9 times per day were voltage changes of 9 V or more. Therefore, in the case of this embodiment, for facility 5 from which the power data DP and voltage data DV shown in Figs. 7 and 8 that form the basis of the ideal voltage adjustment amount data DVr were obtained, a combination of a mechanical voltage regulator and a semiconductor high-speed voltage regulator will be 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 operating status of the facility as in this embodiment, it becomes possible to more precisely save power at the consumer's facility depending on the operating status of the facility.

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

[0182] Therefore, it is not possible to determine with certainty the value of the effective estimated power saving when multiple voltage regulators are installed. However, by taking the power loss amount 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] <Variations> For the customer's equipment 5 provided in the 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 amount of power saving may be calculated, or for the customer's equipment 5 provided in the 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 amount of power saving may be calculated.

[0184] In the first and second embodiments, the time-series data acquisition unit 111 of the voltage regulator selection device 100 acquires the power data DP and the voltage data DV, which are time-series data on the power P and the voltage V, and these power data DP and voltage data DV are used in subsequent processing. However, instead of this, the time-series data acquisition unit 111 may acquire time-series data on the current I (current data) instead of the power data DP, and generate the power data DP by calculating the 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 also 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 such a case, it becomes possible to select an appropriate voltage regulator based on information about the adjustment speed (adjustment time) of the voltage regulator.

[0187] In the first to fourth embodiments described above, three types of voltage regulators are selected as candidates for selection, but other types of voltage regulators may be selected as candidates. Furthermore, 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 these set conditions, thereby selecting one or more voltage regulators 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 an electricity consumer having electrical equipment connected to a low-voltage distribution system, 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 plurality of predetermined candidate voltage regulators based on the power saving judgment index data.

2. A voltage regulator selection device as claimed in claim 1, 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.

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

4. A voltage regulator selection device as defined in claim 1 or 2, wherein said power saving determination index data generation unit generates P-V characteristic index data, which is time-lapse data of a ratio of power change per unit power to voltage change per unit voltage at said candidate installation location, based on said time-lapse data or said alternative data; generates voltage target value data, which is time-lapse data of the voltage value at said candidate installation location when the power consumption of the equipment is minimized while keeping the operating status of the equipment substantially the same as when the time-lapse data is obtained, based on said P-V characteristic index data and a management range of voltage in said 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 said candidate installation location when the equipment is operated in accordance with the voltage target value data while keeping the operating status of the equipment substantially the same as when the time-lapse data is obtained, based on said voltage target value data; and said voltage regulator selection unit selects said one or more voltage regulators based on said ideal voltage adjustment amount data.

5. A voltage regulator selection device according to claim 4, wherein said power saving determination index data generation unit generates, as said P-V characteristic index data, time-lapse data of a P-V characteristic index α obtained by the formula α = (1 - P / P0) / (1 - V / V0), where P and V are the power and voltage values ​​measured at an arbitrary timing in the time-lapse data of power and voltage at said candidate installation location, respectively, and P0 and V0 are the power and voltage values ​​measured immediately before said timing, respectively, and generates said ideal voltage adjustment amount data based on said voltage target value data and the time-lapse data of voltage at said candidate installation location.

6. A voltage regulator selection device according to claim 5, wherein said power saving determination index data generation unit calculates the P-V characteristic index α only for timing when the difference value between V and V0 in the time-lapse data of voltage at said candidate installation location is equal to or greater than a predetermined reference value, and for timing when the difference value does not exceed said reference value, the value of the P-V characteristic index α is set to the same as the value at the immediately preceding timing.

7. A voltage regulator selection device as defined in claim 4, wherein said power saving determination index data generation unit generates composite power data, which is the alternative data for the power data over time at said candidate installation location, by synthesizing power data over time for individual equipment included in said equipment, and generates said P-V characteristic index data based on said composite power data, the power data over time for said individual equipment, and an index value of the power-voltage characteristic for said individual equipment, which is fixedly determined in advance according to the type of said individual equipment.

8. A voltage regulator selection device as claimed in claim 4, wherein 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 equal to or greater than a predetermined value.

9. 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, comprising: a power saving judgment index data generation unit which 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 position of the voltage regulator on the low-voltage distribution system or alternative data for the historical data; and a voltage regulator selection unit which selects one or more voltage regulators from a plurality of predetermined candidate voltage regulators based on the power saving judgment index data.

10. 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 generating 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.

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