JP2005292948A - Energy saving device and electricity distribution line system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that an energy saving device which maintains a constant voltage does not necessarily work effectively to an inverter device in which a power consumption is not proportional to the square of a source voltage. <P>SOLUTION: The energy saving device that is installed in an electricity distribution system of a customer and minimizes a power consumption of a load connected to it comprises a power measurement means that measures the power of the load side from the installation point, and a voltage regulating means that regulates an output voltage so that the power readout measured by the power measurement means is minimized. Furthermore this energy saving device is equipped with a limiter that limits a voltage value within a predetermined range by setting upper and lower limits to the voltage value outputted from the voltage regulating means. The power measurement means obtains the power by summing up the power of each branch circuit branched from the electricity distribution system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device for energy saving.

  In recent years, from the viewpoint of energy saving, regardless of whether it is an office or a home, activities aiming to reduce power consumption have been performed, and energy-saving devices for supporting it have been proposed.

  As an example, the technology of the conventional energy saving apparatus will be described with reference to FIGS. FIG. 22 is a schematic diagram showing the configuration of a system using the conventional energy saving device. FIG. 23 is a diagram showing a tendency of voltage-power consumption characteristics in a lighting fixture which is a home appliance mainly targeted for energy saving conventionally. And as shown in FIG. 23, when a lighting fixture becomes load, what is called a resistive load characteristic that power consumption increases, so that a voltage rises is shown.

  On the other hand, the power supplied from the power supply destination is set to a higher voltage assuming a voltage drop such as a lead-in line so that the power supply regulation (101V ± 6V) is satisfied even if contract power is used. For this reason, the voltage increases when the load is light. Therefore, the conventional energy-saving device intends to save energy by setting the voltage, which tends to be higher than the rated voltage, to be lower than the rated value of the target device or lower than the rated value to suppress power consumption. This achieves energy saving that is almost proportional to the square of the voltage drop for incandescent bulbs and general fluorescent lamps that are not inverters.

  In FIG. 22, as a specific configuration of the energy saving device 43, as shown in the figure, the voltage passing through the distribution line 45 supplied to the load device 46 is measured by the voltage measuring means 44, and the measured voltage signal 47 is converted into the voltage. The voltage is input to the control unit 48, and the voltage control unit 48 controls the output voltage to be within a predetermined range. That is, the conventional energy-saving device 43 only has to have a minimum output voltage control function.

In addition, as a prior art, the power consumption of the load equipment which has a motor is calculated | required as patent document 1, the difference between the power consumption of the present installation and the power consumption of inverter control driving | operation is calculated | required, and based on power consumption based on the difference in power consumption An energy-saving operation method has been proposed that seeks a merit fee.
Japanese Patent Laying-Open No. 2001-155083 (FIG. 1)

  However, the above-described conventional energy-saving device is mainly effective for a resistive load lighting fixture or the like, but is not necessarily effective for an inverter device whose power consumption is not proportional to the square of the power supply voltage. This will be described with reference to the drawings.

  FIG. 2 is a diagram illustrating a relationship between an input voltage input for a power source of an inverter air conditioner as an example of an inverter device, and a corresponding change in current consumption and power consumption. As shown in FIG. 2, since the inverter device is not a resistive load such as a lighting fixture, the power consumption is not necessarily minimized when the input voltage is low, and the power consumption is rather small when the power supply voltage is high. The power consumption is also low.

Further, when a resistive load and an inverter device are mixed, depending on the operating state of the device, reducing the voltage does not necessarily save energy. That is, when the power consumption of a resistive load such as a lighting fixture is small and the power consumption of an inverter device is large, it is rather energy efficient to increase the voltage. Further, depending on the ratio between the resistive load and the inverter load, the vicinity of the rated voltage may be the minimum point of power consumption.

  As described above, in the present embodiment, for a resistive load such as a fluorescent lamp that is not an inverter, when the power supply voltage is too high than the rated voltage, the power supply voltage is lowered, thereby providing a significant energy saving effect. Can be obtained.

  The situation is different for inverter loads with constant power characteristics. FIG. 3 shows measured values of power consumption and current characteristics with respect to inverter load voltage in an example of an inverter air conditioner. While the voltage is changed by ± 5%, the power is changed only by about ± 1%. Therefore, the current decreases in inverse proportion to the voltage, and decreases when the voltage decreases. . In this case, when the distribution line loss is taken into account, the power consumption may increase as the voltage is lowered. That is, as shown in FIG. 2, when the wiring length is 10 m, the power consumption decreases as the voltage decreases. However, when the wiring length is 30 m, the power consumption increases as the voltage decreases. At 20 m, the rated voltage is 100 V and the power consumption is minimized. In this way, the voltage that minimizes power consumption varies depending on the wiring length and load characteristics. Therefore, to save energy, it is necessary to set the voltage to minimize power consumption while measuring power consumption. Understand.

  In view of the above-described conventional problems, the present invention performs power supply voltage control so that power consumption is minimized while constantly monitoring power consumption of an energy saving target. Accordingly, an object of the present invention is to provide an energy-saving device that performs energy-saving control regardless of the load characteristics of the target device.

  In order to solve the above problems, an energy saving device of the present invention is an energy saving device that minimizes the power consumption of a load that is installed and connected to a distribution line system in a consumer. Power measurement means for measuring and voltage control means for controlling the output voltage so that the power measurement value measured by the power measurement means is minimized. Moreover, the energy-saving device of the present invention is provided with a limiter that sets upper and lower limit values for the voltage value output from the voltage control means and limits the voltage value within a predetermined range. The power measuring means calculates the power obtained for each branch circuit branched from the distribution line system.

  In the energy saving device of the present invention, the voltage control unit detects a voltage value that minimizes the power consumption, and controls the output voltage so as to be the voltage value. The voltage control means detects the output voltage value at which the output power is minimized by changing the output voltage within the allowable output voltage range. In addition, the voltage control means detects an output voltage value at which the power consumption is minimized every predetermined elapsed time. Further, the voltage control means detects the output voltage value at which the minimum power consumption is obtained by performing a quadratic curve approximation calculation from the data of at least three stages of output voltages and the power consumption at that time.

  The energy-saving device of the present invention is an energy-saving device that minimizes the power consumption of a load that is installed and connected to a distribution line system in a consumer, and voltage measuring means that measures the voltage on the load side from the point of installation. And voltage control means for controlling the voltage so that the input voltage of the load becomes a target voltage value. Further, the energy saving control target is set only to a load having a resistive load characteristic in which power consumption increases as the input voltage increases. Moreover, it has a calculation means which calculates and calculates | requires the voltage value output from a voltage control means in consideration of the impedance of the distribution line from the installation point which installs an apparatus to a load.

  By controlling the power supply voltage so that the power consumption is minimized while measuring the power consumption, an energy saving effect can be obtained regardless of conditions such as the type of load and the length of the distribution line.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The energy saving apparatus of Embodiment 1 of this invention is demonstrated using FIG. FIG. 1 is a diagram showing a system using an energy saving device according to the present embodiment, where 4 is a load to be saved and 5 is a distribution line up to the load. Reference numeral 1 denotes an energy saving device, which includes power measuring means 3 and voltage control means 2.

  In FIG. 1, the output of the voltage control means 2 of the energy-saving device 1 is connected to the load 4 via the distribution line 5, and the power measurement means 3 measures the combined power of the distribution line 5 and the load 4, and the result The acquired power consumption is input to the voltage control means 2. And the voltage control means 2 controls an output voltage so that the output electric power of the energy saving apparatus 1 may become the minimum. A detailed output voltage determination method and output voltage control method in the voltage control means 2 will be described later.

  That is, the present embodiment is characterized in that the voltage supplied to the target load is controlled to be within a predetermined range by the energy saving device provided in the supplied power system.

  Here, the reason why the energy saving apparatus having such a feature contributes to energy saving will be described with reference to FIG. FIG. 3 is a diagram showing the relationship between the input voltage and power consumption of the air conditioner system including the wiring loss for each wiring length.

  As described above, in the case of resistance such as a fluorescent lamp whose load is not an inverter, the power consumption is almost proportional to the square of the voltage, so that energy saving can be realized by lowering the power supply voltage. However, in general, inverter devices such as inverter air conditioners often have constant power characteristics. In such inverter devices with constant power characteristics, the current increases when the voltage is lowered, contrary to the resistive load, and distribution line loss occurs. May increase. That is, considering the total loss including the loss of the distribution line, for example, as shown in FIG. 3, depending on the length of the distribution line, when the voltage is increased and the power consumption is reduced and the energy is saved, the voltage is reduced. May be energy saving, or the intermediate potential may be energy saving, and the tendency is not uniform.

  Therefore, in order to obtain an energy saving effect regardless of conditions such as load type and distribution line length, as shown in this embodiment, power supply voltage is controlled to minimize power consumption while measuring power consumption. By doing so, power consumption can be minimized.

  Next, a second example obtained by developing the present embodiment will be described with reference to FIG. The embodiment in FIG. 4 is characterized in that the energy-saving device 1 shown in FIG. 1 is provided with a limiter 6 that sets an upper limit and a lower limit on the output voltage value of the voltage control means 2. By providing the limiter 6, it is possible to prevent a high or low voltage from being input to the load 4, so that an overvoltage is not applied to the load 4 or an operation failure of the load 4 is prevented. .

  Next, an installation method for installing the energy saving apparatus according to the present embodiment in a power distribution system in a consumer will be described with reference to FIG. FIG. 5 is a diagram showing an example of the installation position of the energy-saving device in the above-described embodiment, where 7 is a power receiving point for receiving power supply from the outside in the consumer, 9 is a branch point on the power source side, and 10 is a load. Indicates the branch point on the side. Reference numeral 8 denotes a trunk circuit between the power receiving point 7 and the branch point 9, 11a to 11d denote branch circuits between the branch point 10 and the loads 4a to 4d, and 12 denotes a load connection point.

  And the energy-saving apparatus 1 may install any of the above-mentioned receiving point 7, the branch points 9 and 10, and the load connection point 12 as an installation point. Further, the energy saving device 1 may be installed using any point on the main circuit 8 and the branch circuits 11a to 11d as an installation point.

  In this way, the energy saving device can be installed anywhere in the power distribution system in the consumer, and the power supply voltage supplied from the arbitrary installation point to the load side can be controlled to perform energy saving control of the load.

  Furthermore, another embodiment of the installation will be described with reference to FIG. FIG. 6 is a diagram illustrating an example in which the energy-saving device 1 is installed on the power source side of the branch point, and the voltage is measured by one voltage measuring unit at the branch point 9 on the power source side. In order to measure the total power of a plurality of branch circuits, current detectors 13a and 13b are attached to the branch circuit to be measured (branch circuits 11a and 11b in this embodiment), and The power of each branch circuit is measured from this voltage and the current of each branch circuit 11a, 11b, and the total power of the plurality of branch circuits is obtained from the sum.

  In this embodiment, the energy is controlled by adjusting the voltage so that the total power of each branch circuit obtained as described above is minimized.

  In FIG. 6, when the loads 4a and 4b are lighting devices that are resistive loads that are not inverters, the power of each branch shows the same tendency that the power consumption decreases if the voltage is lowered. It is only necessary to perform control to lower the voltage while measuring the total power of a plurality of branch circuits. In this way, by selecting the devices that are subject to energy-saving control with the same type of voltage-power consumption characteristics, the energy-saving device 1 can perform energy saving more efficiently than selecting the target load randomly. It becomes possible.

  In addition, when the secondary branch is further performed at the secondary branch point 10c in the middle of the branch circuit 11d as shown in FIG. 7, by installing the energy saving device 1 on the power source side of the secondary branch point, It is also possible to perform energy saving control by narrowing down the target equipment.

  Next, in the energy saving apparatus 1 described above, an output voltage control method set to an output voltage that minimizes power consumption will be described with reference to FIG. FIG. 8 is a flowchart showing the output voltage control procedure performed in the present embodiment. In FIG. 8, first, in step 1, a predetermined time T1 is set. The predetermined time T1 is a control cycle for controlling the voltage output, and is set to, for example, 30 minutes in the present embodiment.

  At the same time, the elapsed time T2 is reset to zero. The energy saving device 1 has a built-in timer, and the elapsed time T2 is counted by the timer thereafter.

 Next, in step 2, it is obtained from the elapsed time T2 timer. In step 3, T2 and T1 are compared, and steps 1 to 3 are repeated until 30 minutes have elapsed.

Next, when the elapsed time exceeds T2, that is, 30 minutes, the process proceeds to step 4, where the variable n is set to 0, and in step 5, the output voltage Vn is obtained as Vn = 95 + 0.5n (V). In step 6, the power consumption Wn of the load at the output voltage Vn is measured, and each output voltage Vn and the power consumption Wn at that time are stored in a built-in memory. Further, n is incremented by 1 in step 7, n is compared with 20 in step 8, and steps 5 to 8 are repeated until n exceeds 20. In other words, increase the output voltage of the energy-saving device in steps of 0.5V from 95V to 105V, for example.
The output voltage and power consumption at each stage from the output voltage 95V to 105V are stored in the memory.

Next, when the measurement of the power consumption up to the output voltage Vn of 105 V is completed, in step 9, the minimum value of the power consumption Wn and the output voltage Vn at that time are obtained from the contents stored in the memory, and the future output voltage is further determined as Vn. To fix. And it returns to step 1 and the output voltage from an energy-saving device maintains Vn until the next 30 minutes pass.

  Instead of storing Vn and Wn at each stage in the memory, only the minimum value of Wn and Vn at that time may always be updated and stored at each stage where the voltage is boosted. Thereby, memory capacity can be saved.

  Note that the above set value is an example, and if the step size and elapsed time are made finer, it is possible to perform processing that is more continuous without increasing the change in output voltage. Further, if the step size is increased, the next output voltage set value can be found in a shorter time. If the variable range of the output voltage is made wider, the energy saving effect is increased, and if it is made narrower, the next output voltage set value can be found in a shorter time.

  Further, from the second time after the first set voltage is determined, step 6 to step 9 may be replaced with step 10 shown in FIG. That is, in step 9, after the predetermined time T1 (30 minutes) has elapsed, when the previously determined output voltage is V and the predetermined voltage width is dV, the current output voltage V by the energy saving device 1 is changed by ± dV with reference to the current output voltage V. Then, the power consumption on the load side at the three output voltage levels is measured. At this time, if the voltage when the output voltage is changed by ± dV deviates from the upper and lower limit values of the voltage control range, the deviating output voltage is reset to the upper and lower limit values. Then, the output voltage value at which the power consumption at the three levels of voltages is the smallest is set as the next output voltage, and is fixed for the next predetermined time. In addition, about 1V-3V is appropriate as a value of dV.

  Further, if the value of dV is reduced (for example, about 0.2 V) and the predetermined time is also decreased (for example, 30 seconds), the power consumption can be minimized almost continuously without changing greatly. In the above example, the power consumption is measured in three stages, but the number of measurement stages may be four or more.

  Furthermore, the method for determining the output voltage shown in FIG. 9 is not determined from any of the three stages, but the power consumption value is minimized by quadratic curve approximation from the power consumption value at each voltage value. A voltage value may be obtained. That is, as shown in FIG. 10, W (V1), W (V2), and W (V3) are obtained for the power consumption at each of the three output voltage values V1, V2, and V3. From this quadratic approximate curve, the minimum point W (Vn) of the power consumption and the output voltage Vn at that time are obtained. Then, returning to step 1 in the flowchart of FIG. 9, the set voltage of the power supply voltage is fixed to Vn for the next predetermined time T1 (30 minutes).

  FIG. 10 shows a case where the minimum point obtained from any three points by the secondary approximate curve is within the voltage control range, but FIG. 11 is used when the obtained minimum point deviates from the voltage control range. I will explain. FIG. 11 is a diagram showing an approximate curve when the minimum point V obtained from the three-stage output voltage values V1, V2, and V3 exceeds the upper limit value of the voltage control range. In this case, the upper limit value of the voltage control range is shown. Vh is the set voltage Vn of the power supply voltage.

  In the above, the method for setting the output voltage value when the voltage value that minimizes the amount of power consumption is indefinite, such as an inverter device, has been described. However, in the case of a resistive load, the voltage that makes the load energy-saving For example, it is best to make it constant, for example, about 5% lower than the rated voltage. Therefore, when the device connected to the distribution line has the characteristic of a resistive load, as shown in FIG. 12, only the voltage measurement means 16 is provided in the distribution line, and the voltage value measured by the voltage measurement means 16 is used as the voltage control means. 2, the voltage control means 2 can perform control so that the output voltage value is constant. By doing in this way, the measurement of an electric current value can be abbreviate | omitted and energy-saving control is attained only by measuring a voltage value.

  Moreover, the case where there is a distance from the device 4 to be saved by the energy saving device 1 and the impedance of the distribution line cannot be ignored will be described with reference to FIG. In FIG. 13, the energy saving apparatus 1 includes a measuring unit 18 that measures the output voltage V0 and the output current I to obtain an electric energy and a power factor, a storage unit 20 that stores in advance the impedance Z of the distribution line from the device to the device, A calculation means 19 for calculating a voltage value at the input end of the device 4 from the power amount and power factor obtained by the measurement means 18 and the distribution line impedance Z stored in the storage means 20 is provided.

  The energy-saving device 1 outputs from the voltage control unit 17 the voltage value V0 obtained by the calculation unit 19 in consideration of the impedance Z of the distribution line so that the voltage value at the input end of the device 4 becomes the target voltage value V1. . In the calculation means 19, the voltage value V0 is obtained by V0 = V1 + Z × I.

  FIG. 14 is a diagram illustrating an example in which the energy-saving device 1 is installed in a single-phase three-wire circuit on the secondary side of the transformer 21 with an intermediate tap on the secondary side, and a power measurement circuit is independently provided for each system. 3 and voltage control means 2. Then, the output voltage is controlled such that the power is measured independently and the measured power is reduced.

  By doing so, even when the load connected to each phase is different and the voltage at which the power consumption is minimized is different, it is possible to perform the control so that the power consumption is minimized for each phase.

  Then, the voltage control means in the energy saving apparatus 1 demonstrated above until now is demonstrated.

  FIG. 15 is a diagram illustrating an example in which the energy saving device 1 described above is configured with an inverter circuit 22 as an example of realizing the energy saving device 1. In FIG. 15, the inverter circuit 22 includes a transformer 24 and an inverter unit 23 whose secondary side is connected in series to the distribution line. The inverter circuit 22 controls the voltage value output to the secondary side of the transformer 24 in the inverter unit 23. As an example of this method, the output voltage can be increased when the voltage on the secondary side of the transformer 24 is in phase with the power supply voltage, and can be decreased when the voltage is reversed. This inverter circuit is an example, and other configurations may be used.

  Further, as another method of the voltage control means in the energy saving device 1, an example constituted by a tapped transformer and a tap switching means will be described with reference to FIGS. FIG. 16 shows an example in which a transformer with a tap is formed, and FIG. In addition, all other structures, such as an electric power measurement means, are abbreviate | omitted and all can change a voltage stepwise by switching the taps 26 and 29. FIG.

  Note that this circuit is an example, and other configurations may be used. For example, although the transformer with a tap of FIG. 16 has a tap 26 on the secondary side, a tap may be provided on the primary side, and the tap switching means may be connected to the primary side of the transformer.

  As described above, as the voltage control means in each of the above-described examples of the present embodiment, such a tapped transformer or a tapped single transformer and a tap switching means are used to control the power supply voltage and perform energy saving control. .

  Further, as another method of the voltage control means in the energy saving device 1, an example constituted by reactance, a switch element, a reactor, a transformer with a tap and a tap switching means will be described with reference to FIGS.

In FIG. 18, the voltage control means in the energy saving device 1 is configured by connecting a plurality of capacitors 32 and a plurality of reactors 33 via a plurality of switch elements 31 to a reactance 30 connected in series to a distribution line and a load side thereof. doing.

  In the voltage control means having such a configuration, the voltage dividing circuit of the reactor 30, the plurality of reactors 33, and the capacitor 32 is configured by turning on and off the plurality of switch elements 31, and the output voltage to the load side is varied stepwise. Can do. For example, when the reactor 33 is connected by the switch element 31, the output voltage decreases, and when the capacitor 32 is connected, the output voltage increases.

  Here, if the capacitances of the reactor 33 and the capacitor 32 are set to different predetermined capacities, the same combined capacity and step size can be realized with fewer circuits. For example, if it is desired to set the output voltage step size to 5 kvar with a delay of 20 kvar due to the reactor, and if it is configured with a reactor of the same capacity, four 5 kvar reactors and four switch elements are required. On the other hand, by changing the capacity of the reactor and increasing the types of connection patterns for switching the switch elements, one 10 kvar reactor and two 5 kvar reactors, that is, a total of three reactors and three switch elements, the same combined capacity, The step size can be realized.

  FIG. 19 shows an example in which a capacitor with a reactor is used instead of the capacitor alone. This is a countermeasure against the fact that there are cases in which harmonics are magnified with a single capacitor.

  Further, if the reactance of the power distribution line is used instead of the reactor 30 shown in FIGS. 18 and 19, the reactor 30 may be omitted or the capacity can be reduced even if it cannot be completely eliminated. it can.

  Furthermore, an example of power control using a reactive power generation circuit will be described with reference to FIGS. FIG. 20 shows an example of realizing the voltage control means of the energy saving apparatus 1 described above. The reactance 30 connected in series to the distribution line, the capacitor 35 connected to the load side of the reactor 30, and the load of the reactance 30 And a phase control means 37 for continuously controlling the energization time of the reactor 36. And the reactive power generation circuit 50 is comprised by the phase control means 37 which controls the capacitor | condenser 35, the reactor 36, and the energization time of a reactor continuously.

  Here, the phase control means 37 in FIG. 20 is constituted by, for example, an antiparallel circuit of a thyristor as shown in the thyristor circuit 42 of FIG. 21, and this thyristor circuit 42 sets the firing angle of the thyristor in synchronization with the power supply frequency. By controlling, the reactor can be continuously controlled from the completely off state to the fully energized state. Therefore, for example, when the capacitor 35 in FIG. 20 is set to 10 kvar and the reactor 36 is set to 20 kvar, the reactive power control is continuously performed from the advance 10 kvar to the delay 10 kvar by controlling the energization time of the reactor 36 by the phase control means 37. Is possible. As a result, the output voltage is determined by the divided value of the reactor 30 and the reactive power generation circuit 50.

Another configuration example of the reactive power generation circuit 50 will be described with reference to the single-phase connection diagram of FIG. FIG. 21 is a diagram illustrating an example of a circuit configuration of the reactive power generation circuit 50, in which 38, 39, and 41 are reactors, 40 is a capacitor, and 42 is a thyristor circuit. In the reactive power generation circuit 50 having such a circuit configuration, when the thyristor circuit 42 is in a non-energized state, current flows only in the series circuit of the reactors 38 and 39 and the capacitor 40, and the capacitance of the capacitor 40 is larger than the capacitance of the reactors 38 and 39. Since it is set large, the maximum leading reactive current flows. On the other hand, when the thyristor circuit 42 is brought into a full conduction state, a maximum delay current flows. This is because a large current flows through the path of the reactors 38 and 41 and the divided voltage of the reactors 38 and 41 is applied to the series circuit of the reactor 39 and the capacitor 40, so that the advance current flowing through the capacitor 40 is reduced. . Further, when the reactive power generation circuit 50 is used, the harmonic current can be reduced, and the capacities of the capacitor and the reactor can be reduced.

  As described above, according to the present embodiment, the power supply voltage is controlled so that the power consumption is minimized while measuring the power consumption, so that the load type and the distribution line length are not affected. Energy saving effect can be obtained. In addition, since the upper and lower limit values can be set for the output voltage, it is possible to prevent an overvoltage from being applied to a device that is an object of energy saving or an operation failure caused by an input voltage that is too low. Furthermore, it can be installed anywhere in the power distribution system in the consumer, and energy saving including loss of distribution lines can be realized as well as energy saving of the energy saving target device.

  In addition, since the total power of a plurality of branch circuits can be obtained, energy saving control can be performed so that the total power of each branch circuit is minimized. In addition, since only loads with the same tendency of voltage-power characteristics are targeted for energy saving control, more effective energy saving control is possible compared to selecting a target at random. In addition, since the power supply voltage setting is changed so that the power consumption of the load is minimized at a predetermined time interval, the voltage-power characteristics change due to changes in the operating equipment and its operating status. Even so, optimal energy saving control can always be realized.

  Moreover, energy saving control corresponding to a change in a target load can be performed by finely setting a voltage to be examined for a predetermined time. Further, if the number of voltage points to be considered is 3, the memory capacity for performing the calculation can be reduced.

  Furthermore, by obtaining a voltage that minimizes power consumption by quadratic curve approximation, high-accuracy and high-speed energy-saving control is possible. In addition, an energy-saving device is installed between the connection points of equipment, that is, between the distribution line and the equipment, and the voltage supplied to the equipment is controlled to a certain target voltage, so that optimum energy-saving control can be realized for the target equipment. In addition, since the energy drop control is performed by subtracting the voltage drop in the distribution line to the device, the target device operates most efficiently even if the energy-saving device is not installed near the target device. Voltage can be done.

  In addition, since each single-phase three-wire system has a power measurement circuit and voltage control means independently, even if the load connected to each phase is different and the voltage that minimizes power consumption is different, Control that minimizes the power consumption for each phase is possible. Further, since the inverter circuit is configured as an example for realizing the voltage control means, it is possible to set the output voltage with higher speed and higher accuracy.

Furthermore, since the voltage control means is composed of a transformer with taps and a tap switching means, the loss of the energy saving device itself can be reduced. Moreover, since the voltage control means is configured by connecting a plurality of capacitors and a plurality of reactors via a plurality of switching elements on the load side and a reactance connected in series to the distribution line,
With a simple circuit, an energy-saving device with little loss can be realized. Moreover, it can implement | achieve with fewer circuits by setting the capacity | capacitance of a reactor and a capacitor | condenser to a different capacity | capacitance. Furthermore, it is possible to realize an energy-saving device that can control voltage with a continuous value with a simple circuit with a simple circuit.

  Since the present invention measures the amount of electric power and outputs voltage so that power consumption is minimized, it can be widely used as an energy-saving device for devices that operate by receiving power supply.

The figure which shows the system using the energy-saving apparatus in embodiment of this invention Diagram showing voltage-power and current characteristics of inverter air conditioner The figure which shows the characteristic in one actual measurement example of the power consumption including the distribution line of the inverter air conditioner The figure which shows the system using the energy-saving apparatus of the 2nd Example in embodiment of this invention The figure which shows the example of the installation position of the energy-saving apparatus in this Embodiment The figure which shows the example which installed the energy-saving device in the power source side of the branch point The figure which shows the example which installed the energy-saving device in the power supply side of the secondary branch point The flowchart which shows the control procedure of the output voltage performed in embodiment of this invention The flowchart which shows the control procedure of the output voltage performed in another Example of embodiment of this invention The figure explaining obtaining the minimum point from the output voltage 3 points by the secondary approximate curve 2nd figure explaining obtaining | requiring a minimum point by a secondary approximate curve from 3 output voltage points The figure which shows the system using the energy-saving device which controls so that the voltage value in embodiment of this invention may become fixed The figure which shows the system using the energy saving device which controls in consideration of the impedance Z of the distribution line The figure which shows the system which used the energy-saving apparatus for the single-phase three-wire circuit of the secondary side of the transformer with an intermediate | middle tap in the secondary side in embodiment of this invention The figure which shows the system using the energy-saving device comprised with the inverter circuit in embodiment of this invention The figure which shows the system using the energy-saving device which comprised the voltage control means with the transformer with a tap in embodiment of this invention The figure which shows the system using the energy-saving device which comprised the voltage control means with the autotransformer with a tap in embodiment of this invention The figure which shows the system using the energy-saving device which has reactance and the switch element in embodiment of this invention The figure which shows the system using the energy-saving apparatus of another Example which has reactance and switch element in embodiment of this invention The figure which shows the system using the energy-saving device which comprised the voltage control means using the reactive power generation circuit in embodiment of this invention The figure which shows an example of the circuit structure of a reactive power generation circuit Schematic showing the system configuration using a conventional energy-saving device Figure showing the trend of voltage-power consumption characteristics

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Energy-saving device 2 Voltage control means 3 Electric power measurement means 4, 4a-4g Load 5 Distribution line 6 Limiter 7 Power receiving point 8 Trunk circuit 9 Power supply side branch point 10 Load side branch point 11a-11d Branch circuit 12 Load connection point 28 With tap Autotransformer 26, 29 Tap switching means 25 Transformer with tap 26 Tap switching means 30, 33, 34 Reactor 31 Switch element 32, 35 Capacitor 37 Phase control means 50 Reactive power generation circuit

Claims (18)

An energy-saving device that minimizes the power consumption of a load that is installed and connected to a distribution line system in a consumer. The power measurement means measures the power on the load side from the installed point, and the power measured by the power measurement means An energy-saving device provided with voltage control means for controlling the output voltage so that the measured value is minimized. The energy-saving device according to claim 1, further comprising a limiter that sets upper and lower limit values to a voltage value output from the voltage control means and limits the voltage value within a predetermined range. The energy saving device according to claim 1 or 2, wherein the power measuring means calculates the power obtained for each branch circuit branched from the distribution line system. The energy-saving device according to any one of claims 1 to 3, wherein the voltage control means detects a voltage value at which power consumption is minimized and controls the output voltage so as to be the voltage value. 5. The energy saving apparatus according to claim 4, wherein the voltage control means detects the output voltage value at which the output power is minimized by changing the output voltage within an allowable output voltage range. 6. The energy-saving device according to claim 4, wherein the voltage control means detects an output voltage value at which the power consumption is minimized every predetermined elapsed time. 7. The energy-saving device according to claim 5, wherein the voltage control means detects an output voltage value which becomes a minimum power consumption by performing a quadratic curve approximation calculation from data of at least three stages of output voltages and power consumption at that time. . An energy-saving device that minimizes the power consumption of a load that is installed and connected to a distribution line system in a consumer, voltage measuring means for measuring the voltage on the load side from the installed point, and the input voltage of the load is a target voltage An energy-saving device comprising voltage control means for controlling the voltage so as to be a value. The energy saving control according to claim 8, wherein the energy saving control target is set only to a load having a resistive load characteristic in which power consumption increases as the input voltage increases. The energy-saving device according to claim 8 or 9, further comprising calculation means for calculating and obtaining a voltage value output from the voltage control means in consideration of an impedance of a distribution line from an installation point where the device is installed to a load. The energy-saving device according to any one of claims 1 to 10, wherein the voltage control means is an inverter circuit. The energy-saving device according to any one of claims 1 to 7, and 11, wherein the energy-saving device is installed in a single-phase three-wire circuit, has two systems for measuring power, and measures power on the load side independently for each system. The energy-saving device according to any one of claims 1 to 12, wherein the voltage control means includes a tapped transformer and a tap switching means, or a tapped single transformer and a tap switching means. The voltage control means includes a first reactor connected in series to the distribution line, a first switch means connected to a load side of the first reactor, and a plurality of series circuits of first capacitors, The energy-saving device according to any one of claims 1 to 12, comprising switch means connected to the load side of the first reactor and a plurality of series circuits of the second reactor. The energy saving device according to claim 14, wherein constants of the first capacitor and the plurality of second reactors are different. The voltage control means comprises a first reactor connected in series to a distribution line, and a reactive power generation circuit having a phase control means connected to the load side of the first reactor. The energy-saving device described in 1. A distribution line system comprising: a distribution line system wired in a consumer; and an energy-saving device that controls an output voltage so as to minimize power consumption of equipment installed and connected to the distribution line system. The point where the device is installed is at least a point on the trunk circuit from the power receiving point that receives power supply to the power supply side branch point and a point on the branch circuit from the load side branch point to the load connection point that connects the load. Distribution line system that is either. 18. The distribution line system according to claim 17, wherein the energy-saving device to be installed is installed at a point on the circuit so that a load targeted by the energy-saving device has the same tendency of voltage-power consumption characteristics.