JP2011062062A - Distributed power supply system and distributed power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress voltage rise at an interconnection point in a distribution system, in which distributed power supplies are especially introduced in a large quantity, without increasing the cost. <P>SOLUTION: A transformer 5 for power distribution includes a transforming portion adjusting a serving end voltage of the transformer for power distribution, based on a predetermined target voltage value, and a controller 6 which controls the transforming portion by setting the target voltage value to a low value, to such an extent that the voltage of a distributed power supply device receiving the serving end voltage adjusted, according to the target voltage value goes over a lower control limit of a predetermined management range. The distributed power supply device has an inverter that converts a DC power converted from a predetermined energy into an AC power to output it to a power distribution line, and a detection part for detecting the current and voltage of the interconnection point. Moreover, a power generation output control unit is prepared for detecting effective power and reactive power from a detected current and voltage and outputting a delay-phase reactive power, when the detected voltage is equal to or less than a preset threshold. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a distributed power supply system and a distributed power supply apparatus, and more particularly to a technique for appropriately suppressing a lower limit deviation of an appropriate range of a voltage at a connection point with a power system.

  As part of efforts to create a low-carbon society, the government plans to significantly increase the amount of solar power installed in the country compared to the current amount. And 60% of them are assumed to be for residential use. On the other hand, in such an environment where a large number of distributed power sources capable of reverse power flow such as solar power generation are introduced, various problems are expected to occur on both the system operator side and the customer side.

  Specifically, for example, in areas where the installation density of solar power generation is high, the amount of surplus power sales of solar power generation increases, or power is generated by a fuel cell attached to solar power generation, so It is predicted that the voltage of will be higher.

  However, the voltage of solar power generation and fuel cells installed for homes must be within a certain control range (100 ± 6V for the 100V system and 202 ± 20V for the 200V system) defined by the Electricity Business Law. . Therefore, when there is a possibility of deviating from the management range, control for lowering the voltage is performed. The control for lowering the voltage is performed, for example, by suppressing the power generation output or controlling the voltage by adjusting the generation of reactive power.

  In other words, in the case of solar power generation, when the voltage rises due to an increase in surplus power sales in the daytime, control that automatically suppresses the voltage works even if the amount of solar radiation is large. As a result, power generation by sunlight is suppressed. In other words, there is a problem that the consumer loses the opportunity to sell surplus power.

  As a technique for solving this problem, for example, Non-Patent Document 1 describes a technique for adjusting a voltage by reactive power control that causes reactive power to flow to the system side. Non-Patent Document 2 describes a technique for preventing a deviation from the voltage management range by introducing an SVC (Static Var Compensator). Non-Patent Document 3 describes a method of suppressing a voltage increase in a system by installing a storage battery in each house and accumulating surplus power in the storage battery.

  Furthermore, in Patent Document 1, a voltage control device such as a loop controller is set on the high-voltage system side, and the distribution line is used as a demand area system in a loop shape, so that the voltage on the connection point in the distributed power supply system A technique for suppressing the increase in the amount is described.

JP 2009-71889 A

"A study on the analysis and countermeasures for the decrease variation of each customer's power generation in the case of photovoltaic power generation intensive interconnection", Denki Theory B, Vol. 126, No. 10, 2006 "Voltage rise in distribution system with photovoltaic power generators installed centrally and suppression by SVC", Electrical Engineering B, Vol. 126, No. 2, 2006 “Effects of mass energy introduction and countermeasures”, Agency for Natural Resources and Energy, Electricity and Gas Division, September 8, 2008

  However, when a loop controller is provided to suppress voltage rise, there is a problem that the cost increases accordingly. Especially when a large number of distributed power sources are connected to the system, it is necessary to increase the number of loop controllers according to the number of the power supplies, which increases not only the introduction cost but also the operation management cost. It was.

  The present invention has been made in view of such a point, and in particular, in a distribution system in which a large number of distributed power sources are introduced, it is an object to realize voltage rise suppression at an interconnection point without increasing costs. To do.

  In order to solve the above-mentioned problems and achieve the object of the present invention, the distributed power supply system of the present invention reduces the power received at an extra high voltage to a high voltage and allows a plurality of consumers connected via a distribution line to It is a distributed power supply system including a distribution transformer to be supplied and a distributed power supply device installed in a consumer. And the distribution transformer which comprises this system has the transformer part which adjusts the sending voltage of the distribution transformer concerned based on the predetermined target voltage value, and the sending voltage adjusted according to the target voltage value. When the distributed power supply receives power, the target voltage value is set to a value that is low enough that the voltage received by the distributed power supply can deviate from the lower limit of the predetermined management range, and voltage transformation is performed based on the set target voltage value. A control unit for controlling the unit.

  In addition, a distributed power supply device that is a component of this system includes a power conversion unit that converts predetermined energy into DC power, and the DC power converted by the power conversion unit is converted into AC power and output to a distribution line. A detection unit that detects the current and voltage at the connection point between the inverter and the distribution line, and a power generation output control unit that generates a command signal for adjusting the output current of the inverter and supplies the generated command signal to the inverter And.

  When the active power and reactive power are detected from the current and voltage detected by the detection unit, and when the voltage detected by the detection unit is equal to or lower than a preset threshold value, the power transformer is viewed from the distribution transformer. A phase advance reactive power is output, and a command signal for adjusting the output current of the inverter is generated in accordance with the output amount of the active power and the output amount of the reactive power.

  With this configuration, the voltage of the power supplied from the distribution transformer becomes a lower value, so that the voltage deviates from the upper limit of the management range in the distributed power supply device arranged near the starting end of the distribution line. It ’s less likely to happen.

  Furthermore, when the voltage of the power supplied from the distribution transformer is low, the voltage of the distributed power supply device disposed on the distribution line also exceeds the lower limit of the management range. Since the delayed reactive power is output and the voltage increases, the voltage falls within the management range.

  According to the present invention, a dedicated device for voltage adjustment is introduced even when a large amount of distributed power sources are introduced, resulting in variations in voltage between distributed power sources connected to distribution lines. Without any problem, the voltage at the interconnection point is adjusted to an appropriate value.

It is explanatory drawing which shows the structural example of the power distribution series by one embodiment of this invention. It is a block diagram which shows the structural example of the tap switching transformer at the time of one embodiment of this invention. It is explanatory drawing which shows the outline | summary of the distributed power supply system in the residential area by one embodiment of this invention. It is a block diagram which shows the structural example of the solar power generation by one embodiment of this invention. It is a block diagram which shows the structural example of the electric power generation output control part of the solar power generation by one embodiment of this invention. It is a block diagram which shows the structural example of the fuel cell by one embodiment of this invention. It is a block diagram which shows the structural example of the electric power generation output control part of the fuel cell by one embodiment of this invention. It is a graph which shows the example of the load pattern in the residential area and commercial area by one embodiment of this invention. It is a table | surface which shows the example of allocation of the capacity | capacitance of the load in the distributed power supply system by one embodiment of this invention, photovoltaic power generation, and a fuel cell. It is a graph which shows the example of operation | movement of the distributed power supply by one embodiment of this invention. It is a graph which shows the example of the tap change by the load tap change transformer by one embodiment of the present invention. It is a graph which shows the example of the voltage fluctuation in each node at the time of setting the target voltage value by one embodiment of this invention to 202V. It is a graph which shows the example of the output fluctuation | variation of the solar power generation in the node n101 by one embodiment of this invention. It is a graph which shows the example of the voltage fluctuation in each node at the time of setting the target voltage value by one embodiment of this invention to 198V. It is a graph which shows the example of the output fluctuation | variation of the solar power generation in the node n101 by one embodiment of this invention. It is a flowchart which shows the example of the process in the electric power generation output control part of photovoltaic power generation by one embodiment of this invention. It is a flowchart which shows the example of the process in the electric power generation output control part of the fuel cell by one embodiment of this invention. It is a flowchart which shows the example of the process in the electric power generation output control part of the solar power generation by the other example of one embodiment of this invention. It is a flowchart which shows the example of the process in the electric power generation output control part of the fuel cell by the other example of one embodiment of this invention.

Hereinafter, a mode for carrying out the invention (hereinafter also referred to as this example) will be described. The description will be given in the following order.
1. Configuration example of distribution system 2. 2. Configuration example of tap switching transformer at load 3. Configuration example of distributed power supply system 4. Example of processing in tap switching transformer when loaded Example of processing in the power generation output control unit of solar power generation (example of performing control to suppress the lower limit deviation of the voltage value management range)
6). Example of processing in the power generation output control unit of the fuel cell (example of controlling to suppress the deviation from the lower limit of the voltage value management range)
7). Another example of processing in the power generation output control unit of solar power generation (example in which control for suppressing deviation from the upper limit of the voltage value management range is also performed)
8). Another example of processing in the power generation output control unit of the fuel cell (example in which control for suppressing deviation from the upper limit of the voltage value management range is also performed)

[Configuration example of power distribution system]
FIG. 1 is a schematic diagram showing a configuration example of the power distribution system of this example. A feeder f1 that supplies electricity to a residential area and a feeder f2 that supplies electricity to a commercial area are connected to a distribution substation including the on-load tap change transformer 5 (distribution transformer). The feeder f1 has a line length of 16 km, and nodes n101 to n124 are connected to the feeder f1. A pole transformer (not shown) is connected to each of the nodes n101 to n124, and a load of a house (customer) (not shown) is connected to the pole transformer. And the electric power supplied from the distribution substation through each feeder f1 is transformed into a low voltage by the pole transformer, and is supplied to the house. In addition to the load, each house is provided with a photovoltaic power generation 100, which will be described later with reference to FIG. The line length of the feeder f2 is 2 km, and nodes n201 to n210 are connected to the feeder f2. In each house under the nodes n201 to n210, only the photovoltaic power generation 100 is provided as a distributed power source.

[Example of configuration of tap switching transformer 5 when loaded]
Next, a configuration example of the on-load tap switching transformer 5 in the distribution substation will be described with reference to FIG. An on-load tap change transformer (hereinafter referred to as LRT: Load Ratio Transformer) 5 converts a special high voltage of 22 kV supplied from a transmission line (not shown) into a high voltage of 6.6 kV. At this time, in order to keep the voltage on the low voltage side (secondary side) within a certain range, the transformation ratio is changed uninterrupted according to the fluctuation of the load connected to the LRT 5.

  The LRT 5 includes a transformer 6 and a tap switching controller 7. The transformer 6 includes a primary side tap winding 6a and a secondary side tap winding 6b. The secondary side tap winding 6b is provided with 17 taps every 100V from 6100V to 7700V. It has been. A fixed contact 6c-1 to a fixed contact 6c-17 are provided at the tip of each tap, and are selected by a movable contact 6d as a tap selector, whereby the primary side tap winding 6a and the secondary side tap winding are selected. The turn ratio of the wire 6b changes.

  The movable contact 6d is connected to the current collecting conductor 6g via the current limiting resistor 6e and the current collecting contact 6f. The current limiting resistor 6e is a resistor that limits the circulating current that flows when two taps are bridged during tap switching. The current collecting contact 6f moves on the current collecting conductor 6g based on a command supplied from the tap switching control unit 7, and switches the fixed contacts 6c-1 to 6c-17 selected by the secondary side tap winding 6b.

  The tap change control unit 7 stores in advance a program for changing the tap change timing, and the tap change control unit 7 issues a command to the current collecting contact 6f based on the change timing. The tap position of the secondary tap winding 6b is changed so that the average voltage at the load center point of the feeder f1 and the feeder f2 shown in FIG. 1 is closest to a preset target value. By performing such control in the LRT 5, the supply voltage from the distribution substation is adjusted. The load center point is set at the node n105 in the feeder f1 and the node n203 in the feeder f2.

  In the above-described configuration example of the LRT 5, the target voltage setting at the load center point adjusted by the LRT 5 is set slightly lower than the normally set value. Normally, the voltage supplied to the customer's load through an outlet etc. does not drop beyond the standard, from the central value of the aforementioned voltage management range (101 ± 6V for the 100V system, 202 ± 20V for the 200V system) Generally, it is adjusted to be a high value. However, when a large amount of distributed power sources such as photovoltaic power generation are introduced, there is a case where a problem may occur by setting the target voltage setting of the LRT 5 to a value higher than the central value of the voltage management range as usual. is there.

  In the embodiment shown in FIG. 1, since the node n having the distributed power source is connected to the feeder f1 in a large amount, the line length of the feeder f1 is as long as 16 km. As a result, for example, the voltage difference between the nodes n at the ends, such as the node n101 near the LRT 5 and the node n109 at the end, becomes very large. For this reason, it is necessary to set the supply voltage from the LRT 5 high so that the voltage of the node n109 on the terminal side does not deviate from the lower limit of the management range defined by the Electricity Business Law. For this reason, the voltage of the node n101 inevitably increases.

  If the voltage value exceeds the upper limit of the management range described above due to the transition of the voltage to a higher level, control is performed to suppress the output in the photovoltaic power generation connected to the node n101. In such a case, the customer of the node n101 loses (or reduces) the opportunity to sell surplus power. In order to prevent the occurrence of such a problem, in this example, the control for suppressing the output of the photovoltaic power generation works even if the transmission voltage from the LRT 5 is generated on a sunny day even if the photovoltaic power generation generates power according to the solar radiation intensity. The voltage value is set so as not to exist. Specifically, in the load group in which the photovoltaic power generation is installed, the LRT 5 supply voltage is set so that the voltage immediately below the pole transformer is 107V for the 100V system and less than 222V for the 200V system. That is, the target voltage setting at the load center point adjusted by the LRT 5 is set to a value slightly lower than the conventional setting value that is higher than the median value of the voltage management range (a value less than the median value of the voltage management range). Details of processing in the LRT 5 will be described later.

  In this example, as the LRT 5, the example of applying the pro-con method in which the change timing (time) of the tap position (fixed contact position) is determined in advance is described, but the present invention is not limited to this. For example, another type such as a line voltage drop compensator (LDC) may be adopted as the LRT 5. Moreover, although the example which provided the tap in the secondary side of LRT5 is given in this example, you may make it the structure which provides a tap in a primary side and fixes a secondary side.

[Configuration example of distributed power system]
Next, a configuration example of a distributed power supply system in a residential area will be described with reference to FIGS. FIG. 3 is a diagram illustrating an example of a low voltage distribution system from the pole transformer 10r to each house. The pole transformer 10r takes out a voltage of 100 / 200V from a high voltage of 6.6 kV supplied from a distribution substation as a single-phase three-wire system, and supplies it to a feeder f1 connected to the low voltage side. In this example, the transformation ratio of the pole transformer 10r is unified to 6600 / 202V in all the nodes n in the residential area. That is, the control that is normally performed to set the transformation ratio for the node n on the end side higher than that on the start end side according to the voltage drop of the line is not performed.

  Normally, since the voltage at the node n on the terminal side is lower than the voltage at the node n in the vicinity of the LRT 5, the transformation ratio at the pole transformer 10r on the terminal side is relatively smaller than that on the LRT 5 side ( For example, 6450 / 202V). This is because the voltage on the high voltage side of 6.6 kV can be kept high in the management range by reducing the voltage transformation ratio even if the voltage on the high voltage side of 6.6 kV is low. However, when photovoltaic power generation is installed in large quantities, the voltage increase range due to reverse power flow becomes relatively small by increasing the voltage, and there is a risk that voltage adjustment due to output suppression is necessary in solar power generation. It tends to occur. Therefore, in this example, the transformation ratio of the pole transformer 10r is set to a constant 6600 / 202V in the residential area system nodes of the nodes n101 to n124 regardless of the position.

  A feeder f10 is connected to the low voltage side of the pole transformer 10r, and nodes n1 to n9 are connected to the feeder f10.

  Two houses are connected to each of the nodes n101 to n109, and a distributed power source using the photovoltaic power generation 100 and the fuel cell 300 and a load 200 are installed in each house. The voltage management range at the receiving point of the house is set to a range of 190 to 214V, which is twice the 100V line even in the 200V line so that the management range of 95V to 107V, which is the management range of the 100V line, can be properly maintained.

  In this example, in both the photovoltaic power generation 100 and the fuel cell 300, voltage adjustment control for optimizing the voltage at the interconnection point is performed. As described above, since the voltage at the load center point adjusted by the LRT 5 is set lower than usual as described above, the nighttime voltage particularly at the node n109 on the terminal side may deviate from the lower limit of the appropriate range. Because. Specifically, in the photovoltaic power generation 100 and the fuel cell 300, when the voltage at the connection point falls below a predetermined voltage compensation start threshold (hereinafter also simply referred to as “threshold”) VLP, The output is controlled to increase the voltage. And such reactive power control is made always possible not only in a power generation time zone. For example, when only reactive power is output at night when power generation is not performed, the power factor becomes 0. In this example, however, the power factor of 85% ( In order to prevent a voltage rise, control is not limited to the range of 80%).

[Example configuration of solar power generation]
FIG. 4 is a block diagram illustrating a configuration example of the solar power generation 100 used as one of the distributed power sources in this embodiment. The photovoltaic power generation 100 includes a photovoltaic power generation cell 101, an inverter 102, and a power generation output control unit 103. Photovoltaic power generation cell 101 absorbs light energy by electrons in the element, converts the absorbed light energy into direct current power, and outputs it to inverter 102.

  The inverter 102 converts the DC power output from the photovoltaic power generation cell 101 into AC power, and the obtained AC power is converted to the load 200 and / or the distribution system (pillar transformer 10r) shown in FIG. Output to. In this example, the capacity of the inverter 102 is set to 3.5 kVA.

  The power generation output control unit 103 detects a power generation output and reactive power from a current / voltage at a connection point (not shown), and adjusts the output current of the inverter 102 according to the detected voltage value. An inverter output current command is generated and supplied to the inverter 102. The adjustment of the output current of the inverter 102 is performed in order to keep the output voltage within an appropriate range. In this example, the reactive power control method is used as described above.

  FIG. 5 is a block diagram illustrating a configuration example of the power generation output control unit 103. The power generation output control unit 103 includes a detector 1031, an active power regulator 1032, a reactive power regulator 1033, a current calculator 1034, an inverter output current regulator 1035, an amplifier 1036, and a signal converter 1037. Is included.

  The detector 1031 uses the direct-current output voltage Vdc and direct-current output current Idc output from the solar power generation cell 101 to calculate the electric power PGPt (kW) that can be generated originally from the solar radiation intensity. Further, from the voltage value Vt (V) of the output terminal of the inverter 102 (the connection point with the distribution system (hereinafter also simply referred to as “system”)), the power generation amount PGP (kW) of the active power (hereinafter simply referred to as “power generation”). And the amount of reactive power generated QGP (kvar). Then, the detected power generation amount PGP of the active power is supplied to the active power adjuster 1032 and the reactive power adjuster 1033, and the generation amount QGP of the reactive power is supplied to the reactive power adjuster 1033.

  The active power adjuster 1032 performs control to increase or decrease the output amount of the power generation amount PGP according to the magnitude relationship between the voltage value Vt detected by the detector 1031 and each threshold value or parameter set in advance. As thresholds and parameters set in advance in the active power adjuster 1032, there are (a) a voltage compensation start threshold VLP, (b) a capacity INVPc of the inverter 102, and (c) a power-generating power PGPt.

  As the threshold value VIP, for example, 95.5 V is set as the lowest control target value for keeping the voltage value Vt within an appropriate range. The active power regulator 1032 generates power when the voltage value Vt is greater than the threshold value VLP, the reactive power generation amount QGP is an absolute value other than 0, and the power generation amount PGP is less than the power generation possible power PGPt. Control is performed to increase the amount PGP.

  The reactive power adjuster 1033 performs control to increase or decrease the reactive power generation amount QGP according to the magnitude relationship between the voltage value Vt detected by the detector 1031 and each threshold or parameter set in advance. As each threshold value or parameter, (a) the voltage compensation start threshold value VLP described above and (b) the capacitance INVPc of the inverter 102 are set. The reactive power adjuster 1033 increases the late-phase reactive power generation amount QGP when the voltage value Vt detected by the detector 1031 is equal to or less than the threshold value VLP and the capacity INVPc of the inverter 102 is empty. .

  The current calculator 1034 generates an inverter output current command (AC current waveform) from the active power generation amount PGP output from the active power regulator 1032 and the reactive power generation amount QGP output from the reactive power regulator 1033. To do. Then, the generated inverter output current command is supplied to the inverter output current regulator 1035.

  The inverter output current regulator 1035 calculates the pulse width of the current output from the inverter 102, adjusts the AC current waveform supplied from the current calculator 1034, and outputs the adjusted AC current waveform to the amplifier 1036. The amplifier 1036 superimposes the alternating current waveform output from the inverter output current regulator 1035 on the carrier wave and outputs the superimposed signal to the signal converter 1037. The signal conversion unit 1037 converts the output signal output from the amplifier 1036 into a signal suitable for the inverter 102 and supplies the converted signal to the inverter 102.

[Configuration example of fuel cell]
Next, a configuration example of the fuel cell 300 shown in FIG. 3 will be described with reference to FIG. The fuel cell 300 includes a hydrogen reformer 301, a fuel cell 302, an inverter 303, an exhaust heat recovery unit 304, and a power generation output control unit 305.

  The hydrogen reformer 301 reforms a fossil fuel such as city gas or LP gas to extract hydrogen, and outputs the extracted hydrogen to the fuel cell 302. The fuel cell 302 chemically reacts hydrogen and oxygen output from the hydrogen reformer 301 to generate DC power, and outputs the generated DC power to the inverter 303.

  The inverter 303 converts the DC power output from the fuel cell 302 into AC power and outputs the AC power to the load 200 shown in FIG. In this example, the capacity of the inverter 102 is set to 1.2 kVA. The exhaust heat recovery unit 304 recovers exhaust heat from the hydrogen reformer 301 and the fuel battery cell 302 to generate hot water.

  The power generation output control unit 305 detects the power generation output and reactive power from the current and voltage at the output terminal of the inverter 303, and adjusts the output current of the inverter 303 according to the magnitude of the detected value. A command is generated and supplied to the inverter 303.

  FIG. 7 is a block diagram illustrating a configuration example of the power generation output control unit 305. The power generation output controller 305 includes a detector 3051, an active power adjuster 3052, a reactive power adjuster 3053, a current calculator 3054, an inverter output current adjuster 3055, an amplifier 3056, and a signal converter 3057. Is included.

  The detector 3051 detects a power generation amount PGF (kW) of active power and a generation amount QGF (kvar) of reactive power from the voltage value Vt (V) at the output terminal of the inverter 303. Then, the detected power generation amount PGF of the active power is supplied to the active power adjuster 3052 and the reactive power adjuster 3053, and the generation amount QGF of the reactive power is supplied to the reactive power adjuster 3053.

The detector 3051 calculates the power load PL of the load 200 from the magnitude of the voltage value Vt and current It at the output terminal of the inverter 303 and the operating state of the fuel cell 302. When the fuel cell 302 is stopped, the power load PL is calculated by the following formula.
Power load PL = Voltage value Vt × Current It × cos θ
When the fuel cell 302 is in operation, the power load PL is calculated by the following formula.
Power load PL = Voltage value Vt × Current It × cos θ + Power generation amount PGF

  The active power adjuster 3052 performs control to increase or decrease the output amount of the power generation amount PGF according to the magnitude relationship between the voltage value Vt detected by the detector 3051 and each threshold value or parameter set in advance. The thresholds and parameters set in advance in the active power adjuster 3052 include (a) a voltage compensation start threshold VIF, (b) a capacity INVFc of the inverter 102, (c) a minimum power that can be generated by the fuel cell 302 (hereinafter, “ PGFd, referred to as “turndown value”, and (d) power load PL. As the threshold value VlF, for example, 95.0V is set slightly lower than the threshold value VlP set on the solar power generation side.

  When the voltage value Vt is greater than the threshold value VlF, the active power adjuster 3052 performs control to change the power generation amount PGF following the power load PL.

  The reactive power adjuster 3053 performs control to increase or decrease the reactive power generation amount QGF according to the magnitude relationship between the voltage value Vt detected by the detector 3051 and each threshold or parameter set in advance. . Here, as with the active power adjuster 3052, (a) the voltage compensation start threshold VIF, (b) the capacitance INVFc of the inverter 303, and (c) the turndown value PGFd are set as the thresholds and parameters.

  When the voltage value Vt detected by the detector 3051 is equal to or less than the threshold value VlF and the capacity INVFc of the inverter 303 is empty, the late-phase reactive power generation amount QGF is increased. When the voltage value Vt is larger than the threshold value VlF and the absolute value of the reactive power generation amount QGF is other than 0, control is performed to decrease the absolute value of the reactive power generation amount QGF.

  The current calculator 3054, the inverter output current regulator 3055, the amplifier 3056, and the signal converter 3057 operate in the same manner as the respective units in the power generation output control unit 103 of the solar power generation 100 shown in FIG. The description is omitted here.

[Example of processing in tap change transformer at load]
Next, an example of processing in the LRT 5, specifically, a method for setting the target voltage value at the load center point and a method for setting the tap switching timing will be described.
(1) First, considering the temperature and weather forecast information on the day on which the tap switching timing is to be set (the scheduled date for operating the LRT 5 based on the setting), the load pattern in the distribution system and the operation pattern of the distributed power source Predict.
(2) Next, the power at each time to be supplied on the system side is estimated based on the load pattern predicted in (1) and the operation pattern of the distributed power source.

  FIG. 8 shows an example of an assumed load pattern in the feeder f1 and feeder f2 of the power distribution system shown in FIG. The vertical axis in FIG. 8 shows the load pattern (MW / Mvar) in each feeder f, and the horizontal axis shows the time (hour). In FIG. 8, the active power load output in the commercial area is indicated by a solid line, and the reactive power output in the commercial area is indicated by a dotted line including a marker with a cross. The active power load output in the residential area is indicated by a dotted line including a marker of Δ, and the reactive power in the residential area is indicated by a solid line including a marker of □.

  In the commercial area, it is assumed that the active power load is large between 8 o'clock and 17 o'clock, and the output amount of reactive power is also corresponding to it. In a residential area, the active power load increased from 16:00 to 20:00, but the reactive power load was assumed to be almost constant.

  The load distribution to each node n connected to the feeder f1 and the feeder f2 shown in FIG. 1 is prorated according to the distance of the distribution line to which the node n is connected. FIG. 9 shows an example of the distribution value of the load 200 and the distributed power supply in a residential area. In FIG. 9, the photovoltaic power generation 100 is represented as “PV”, and the fuel cell 300 is represented as “FC”.

  The leftmost column c1 in FIG. 9 shows the number of the node n, and the column c2 shows the load distribution ratio. Column c3 shows the active power load output PL (kW) and the reactive power load output QL (kvar) at the load 200 at 20:00. The column c4 shows the introduction amount (kW) of the photovoltaic power generation 100, and the column c5 shows the introduction amount (kW) of the fuel cell 300. As shown in the lowermost row of the column c4, the total capacity of the photovoltaic power generation system 100 allocated to the residential area is 1.5 MW, and as shown in the lowermost row of the column c5, the fuel cell allocated to the residential area. The total capacity of 300 is 0.225 MW. That is, the load to be supplied and the introduction amount of the photovoltaic power generation 100 and the fuel cell 300 are assigned according to the sum of the distances of the distribution lines to which the node n is connected. That is, the load size of the node n having a long distribution line distance or the branched node n and the introduction amount of the distributed power source are relatively large.

  FIG. 10 shows an example of an active power load pattern per house and an operation pattern of the photovoltaic power generation 100 and the fuel cell 300 per unit. The vertical axis in FIG. 10 indicates active power output (kW) and reactive power output (kvar), and the horizontal axis indicates time (hours). In FIG. 10, the output of the photovoltaic power generation 100 is indicated by a broken line, the output of the fuel cell 300 is indicated by shading, and the load is indicated by a solid line. In the example shown in FIG. 10, the photovoltaic power generation 100 operates from 7 o'clock to 20 o'clock with sunshine, and outputs according to the sunshine intensity. In addition, the fuel cell 300 performs the rated operation in the time zone from 8:00 to 20:00 set as the operation time.

When returning to the setting method of the tap change timing in the LRT5 again, in the LRT5, after the estimation of power at each time to be supplied on the system side in (2) described above is completed,
(3) After fixing the position of the tap to any one of the 17 taps, the load fluctuation corresponding to the load pattern shown in FIG. 8 is added, and the voltage fluctuation at the load center point is calculated.
This operation is repeated by the number of taps, that is, 17 times. As a result, the voltage fluctuation at the center point of the load when the delivery voltage of the LRT 5 is changed from 6100 V to 7700 V in units of 100 V is measured.

(4) Next, an average voltage value at the load center point is calculated using the voltage fluctuation patterns measured at the node n105 and the node n203 which are the load center points.
Specifically, the average value of the voltage value at each time with the same sending voltage is calculated. Then, a tap in which a voltage value closest to the target voltage value at each time is measured is selected from the obtained average voltages. Thereby, provisional tap change timing is set.

(5) Even when the operation is performed based on the tap change timing set in the above (4) and the voltage deviates from the lower limit of the management range at any node n, the node n side (distributed power supply) Side) to perform reactive power control. Then, it is verified whether or not the voltage can be kept within the management range. If the voltage cannot be optimized even by reactive power control on the distributed power source side, the target voltage value is further lowered, and then the process returns to (4) again to continue the processing.
(6) Based on the verification result of (5), the position of the tap in all time zones, that is, the transmission voltage, the voltage of all nodes n can be secured within the management range (in this example, 190 V to 214 V). Set to value.

  FIG. 11 is a diagram showing the relationship between the tap change timing and the tap position set in such a procedure. The tap change timing shown in FIG. 11 is when the target voltage value at the node n105 and the node n203, which are load center points, is 202V. The value of 202 V is calculated as a value that can prevent the voltage management range lower limit deviation at the node n on the terminal side, and normally, the value calculated in this way is set as the target voltage value. . The vertical axis in FIG. 11 indicates the position of the tap, and the horizontal axis indicates time (hour). As shown in FIG. 11, the tap position is switched from the sixth to the tenth at every predetermined change timing from around 7 o'clock to 24 o'clock, so that the sending voltage to each node n is changed. Is adjusted.

  FIG. 12 is a diagram showing voltage fluctuations at the nodes n101, n105, and n109 when the tap position of the LRT 5 is changed at the timing shown in FIG. The vertical axis indicates the voltage value Vt (V) detected at the node n, and the horizontal axis indicates time (hour). The voltage value Vt of the node n101 is indicated by a broken line, the voltage value Vt of the node n105 is indicated by a solid line, and the voltage value Vt of the node n109 is indicated by a one-dot chain line.

  At any node n, the voltage value Vt reaches a peak from 13:00 to 15:00, but at the node n101 on the start side, the voltage value Vt exceeds the upper limit value of 214 V in the management range. It is shown. Further, in the node n101, the upper limit deviation of the management range of the voltage value Vt occurs between 19:00 and 20:00.

  For this reason, in the node n101, the reactive power is output on the photovoltaic power generation 100 side during the time when the upper limit deviation of the voltage value Vt occurs, and the output of the photovoltaic power generation 100 is suppressed. FIG. 13 shows an example of output fluctuation of the photovoltaic power generation 100 at the node n101. The vertical axis in FIG. 13 indicates the output (kW / kvar) of the photovoltaic power generation 100, and the horizontal axis indicates the time (hour). Of the outputs of the photovoltaic power generation 100 in FIG. 13, the active power output is indicated by a solid line, and the reactive power output is indicated by a broken line. According to FIG. 13, the reactive power of the leading phase is output in response to the deviation of the upper limit of the appropriate range of the voltage value Vt around 13:00, and the output of the photovoltaic power generation 100 (active power output) is affected by this influence. Is suppressed. A similar phenomenon occurs at around 19: 00-20: 00.

  FIG. 14 is a diagram showing voltage fluctuations at the node n101, the node n105, and the node n109 when the target voltage value at the load middle point is set to 198V. 198V is calculated as a value that also allows the voltage management range lower limit deviation at the node n on the terminal side. The vertical axis indicates the voltage value Vt (V) detected at the node n, and the horizontal axis indicates time (hour). The voltage value Vt of the node n101 is indicated by a broken line, the voltage value Vt of the node n105 is indicated by a solid line, and the voltage value Vt of the node n109 is indicated by a dashed line.

  In FIG. 14 as well, the voltage value Vt of the node n101 on the start end side is increasing, but the voltage value Vt exceeds 214V, which is the upper limit of the management range, even between 9 o'clock and 21 o'clock when the voltage value Vt rises the most. Things are gone. Thereby, since the deviation of the upper limit of the management range of the voltage value Vt does not occur in each node n on the start end side such as the node n101, the output of the photovoltaic power generation 100 is not suppressed. That is, it is possible to prevent surplus power sales opportunity loss at each node n on the start end side.

  However, as shown in FIG. 14, in the node n109 arranged on the terminal side, the voltage value Vt falls below 190V which is the lower limit of the management range between 21:00 and 24:00 when the operation of the photovoltaic power generation 100 is not performed. The phenomenon is happening.

  As described above, by setting the delivery voltage of the LRT 5 to be low, the voltage value Vt may deviate from the management range lower limit value at a specific node n particularly at night. Therefore, in order to prevent this, in this example, as described above, the photovoltaic power generation 100 and the fuel cell 300 can always output reactive power.

  FIG. 15 is a diagram showing the output fluctuation of the photovoltaic power generation 100 at the node n109. The vertical axis indicates the output (kW / kvar) of the photovoltaic power generation 100, and the horizontal axis indicates the time (hour). The active power output is indicated by a solid line, and the reactive power output is indicated by a broken line. FIG. 15 shows that at the node n109, the delayed reactive power is output from 21:00 to around 24:00 when the voltage value Vt deviates from the lower limit of the management range. By performing such control, the voltage value Vt increases, so that the voltage value Vt falls within the management range (see FIG. 14).

  Next, an example of reactive power control processing in each of the photovoltaic power generation 100 and the fuel cell 300 will be described with reference to the flowcharts of FIGS. 16 and 17.

[Example of processing in the power generation output controller of solar power generation]
First, the threshold value VLP and each parameter are set in the active power adjuster 1032 and the reactive power adjuster 1033 (see FIG. 5) (step S1), and then the voltage value Vt and the power generation possible power PGPt are measured by the detector 1031. (Step S2).

  Next, the reactive power adjuster 1033 determines whether or not the voltage value Vt is equal to or less than the threshold value VLP (step S3). If the voltage value Vt is less than or equal to the threshold value VLP, it is subsequently determined whether or not there is a vacancy in the capacitor INVPc of the inverter 102 (step S4). When the capacity INVPc of the inverter 102 is vacant, control is performed to increase the generation amount QGP of the reactive power in the slow phase when viewed from the photovoltaic power generation 100 side (step S5). If it is determined in step S5 that the capacity INVPc of the inverter 102 is not empty, the process returns to step S2 and the processing is continued.

If it is determined in step S3 that the voltage value Vt is greater than the threshold value VLP, then the reactive power adjuster 1033 determines whether or not the absolute value of the reactive power generation amount QGP is greater than zero. (Step S6). Here, if it is determined that the absolute value of the reactive power generation amount QGP is greater than 0, control is performed to decrease the absolute value of the reactive power generation amount QGP (step S7), and then the process returns to step S2 to be processed. Is continued.
On the other hand, when it is determined in step S6 that the absolute value of the reactive power generation amount QGP is 0, it is subsequently determined whether or not the power generation amount PGP is smaller than the power generation possible power PGPt (step S8). When the power generation amount PGP is smaller than the power generation possible power PGPt, control for increasing the power generation amount PGP is performed (step S9). If the power generation amount PGP is equal to or greater than the power generation possible power PGPt, the process returns to step S2 and the processing is continued.

[Example of voltage adjustment control in a fuel cell]
Next, an example of voltage adjustment control in the fuel cell 300 will be described with reference to FIG. First, the threshold value VIF and each parameter are set in the active power adjuster 3052 and the reactive power adjuster 3053 (see FIG. 7) (step S11), and then the voltage value Vt and the power load PL are measured by the detector 3051. (Step S12).

  Next, the reactive power adjuster 3053 determines whether or not the voltage value Vt is less than or equal to the threshold value VlF (step S13). If the voltage value Vt is equal to or less than the threshold value VlF, it is subsequently determined whether or not the capacity INVFc of the inverter 303 is empty (step S14). Then, when the capacity INVFc of the inverter 303 is available, control is performed to increase the amount of generation QGF of the lagging reactive power as viewed from the fuel cell 300 side (step S15). If it is determined in step S14 that the capacity INVFc of the inverter 303 is not empty, the process returns to step S12 and the processing is continued.

  If it is determined in step S13 that the voltage value Vt is greater than the threshold value VlF, then the reactive power adjuster 3053 determines whether or not the absolute value of the reactive power generation amount QGF is greater than zero. (Step S16). If the absolute value of the reactive power generation amount QGF is greater than 0, control is performed to decrease the absolute value of the reactive power generation amount QGF (step S17). On the other hand, if it is determined in step S16 that the absolute value of the reactive power generation amount QGF is 0, it is subsequently determined whether or not the power generation amount PGF is smaller than the power load PL (step S18). When the PGF is smaller than the power load PL, control for increasing the power generation amount PGF is performed (step S19). If the power generation amount PGF is greater than or equal to the power load PL, the process returns to step S12 and the process is continued.

[Effects of this embodiment]
According to the above-described embodiment of the present invention, the target voltage value of the load center point adjusted by the LRT 5 can be prevented from deviating from the lower limit of the management range of the voltage value at the node n on the terminal side. Since it is set to a value lower than the value, the delivery voltage of the LRT 5 will not increase too much. Thereby, since the output suppression of the photovoltaic power generation 100 at the node n on the start end side is not performed, it is possible to prevent a consumer at each node n on the start end side from losing the surplus power sales opportunity.

  Further, according to the above-described embodiment, the target voltage value of the load center point adjusted by the LRT 5 is set to a value lower than normal (a value equal to or lower than the center value of the voltage management range). The voltage of becomes low. As a result, the voltage value Vt is less likely to deviate from the upper limit of the management range even by the reverse power flow of the photovoltaic power generation 100, so that the number of times output is suppressed can be reduced.

  In addition, according to the above-described embodiment, even if a voltage management range lower limit deviation occurs at the node n on the terminal side by setting the target voltage value of the load center point adjusted by the LRT 5 lower than usual, Since reactive power control is performed on the distributed power source side, the voltage falls within the management range.

  That is, according to the above-described embodiment, the target of the load center point adjusted by the LRT 5 also when the voltage difference between the nodes n connected to the distribution line becomes large due to, for example, when the length of the distribution line is long. The voltage can be easily adjusted by setting the voltage value and adjusting the start threshold of reactive power control on the distributed power source side.

  In addition, when the feeders f having different load patterns (voltage profiles) are generally connected to the same LRT 5 as in the residential area and the commercial area shown in this example, due to the imbalance of the load pattern, The voltage difference between the electric power supplied from the LRT 5 increases. Therefore, it becomes difficult to keep the receiving point voltages of all consumers within the voltage management range. Particularly in residential areas where the track length is relatively long, the voltage changes greatly, and the voltage during the daytime, which is a light load time period, is higher, while the voltage is lower at night, which is a heavy load time period. Transition to Furthermore, when a distributed power source is installed in a residential area, the amount of load supplied by the electric power company is small, and thus the voltage rise in the daytime becomes significant. However, according to the above-described embodiment, the voltage rise is alleviated by setting the sending voltage of the LRT 5 lower, and the voltage is increased on the distributed power source side even in the night time zone when the voltage changes lower. For this reason, excessive voltage drop can be avoided.

  Furthermore, according to the above-described embodiment, the voltage value Vt can be controlled without introducing SVC, SVR (Step Voltage Regulator) or the like, and thus the introduction cost and the operation cost can be reduced. Can do.

  Further, according to the above-described embodiment, the starting threshold for reactive power control on the distributed power source side is set to a lower value on the photovoltaic power generation 100 side than on the fuel cell 300 side. The reactive power control is started first from the side. Thus, even when the voltage value Vt deviates from the lower limit of the management range at night, reactive power control is performed preferentially from the photovoltaic power generation 100 side that does not generate at night. Therefore, when the fuel cell 300 is generating power at night, the risk that the output amount of the generated power will be reduced can be reduced.

  In the above-described embodiment, the transformation ratio of the pole transformer 10r is the same for all the nodes n, that is, the transformation ratio is set higher for the terminal node n. Therefore, the influence of the node n on the terminal side when the voltage rises can be reduced. That is, when the voltage rises, it is possible to prevent the output suppression of the photovoltaic power generation 100 from working at the node n on the terminal side.

  In the above-described embodiment, an example in which the target voltage value of the load center point adjusted by the LRT 5 is set to 198V is described. However, the present invention is not limited to this. Any value may be set as long as it is smaller than a value normally set as the target voltage value at the load center point (a value that does not allow deviation from the voltage lower limit at each node n). Similarly, the threshold values set on the photovoltaic power generation 100 side and the fuel cell 300 side are not limited to the values given in the above-described embodiment.

  In the above-described embodiment, control exceeding the range of the power factor of 85% (80% when preventing voltage rise) defined in the “system interconnection technical requirement guidelines for ensuring power quality” can be performed. Although the example which did so was given, it is not limited to this. For example, by performing reactive power control within the power factor range with the fuel cell 300 at night, the same effect as when reactive power control is performed with the photovoltaic power generation 100 can be obtained.

  In the above-described embodiment, the case where the reactive power control is performed not only on the photovoltaic power generation 100 side but also on the fuel cell 300 side is taken as an example. The present invention may be applied to a configuration in which only output control can be performed. Even in such a configuration, by starting the control on the photovoltaic power generation 100 side first, it is possible to avoid a decrease in the power generation output on the fuel cell 300 side that may be generating power even at night. it can.

  Moreover, although the case where the process for suppressing the lower limit deviation of the management range of the voltage value is performed as an example in the photovoltaic power generation 100 and the fuel cell 300 in the above-described embodiment, the deviation prevention in the upper limit direction is simultaneously performed. You may apply to the structure to perform. Processing in the case where the deviation of the upper limit of the voltage management range can be prevented will be described with reference to FIGS.

[Other examples of processing in the power generation output control unit of photovoltaic power generation]
First, another example of voltage adjustment control in the photovoltaic power generation 100 will be described with reference to the flowchart of FIG. First, the threshold value V1P and the threshold value VhP and the respective parameters are set in the active power adjuster 1032 and the reactive power adjuster 1033 (see FIG. 5) (step S21), and then the voltage value Vt and the electric power PGPt that can be generated are detected by the detector 1031. Is measured (step S22). The threshold value VhP is a threshold value for preventing the voltage value Vt from deviating toward the upper limit of the management range, and is set to 107 V, for example.

  Next, the reactive power adjuster 1033 determines whether or not the voltage value Vt is greater than or equal to the threshold value VhP (step S23). If the voltage value Vt is greater than or equal to the threshold value VhP, it is subsequently determined whether or not there is a vacancy in the capacitor INVPc of the inverter 102 (step S24). When the capacity INVPc of the inverter 102 is vacant, control is performed to increase the generation amount QGP of the advanced reactive power as viewed from the photovoltaic power generation 100 side (step S25). If it is determined in step S24 that the capacity INVPc of the inverter 102 is not empty, after the process of reducing the power generation amount PGP is performed (step S26), the process returns to step S22 and the process is continued.

  If it is determined in step S23 that the voltage value Vt is less than the threshold value VhP, it is determined whether or not the voltage value Vt is less than or equal to the threshold value VLP (step S27). Here, when the voltage value Vt is equal to or less than the threshold value VLP, it is subsequently determined whether or not there is a vacancy in the capacitor INVPc of the inverter 102 (step S28). When it is determined in step S28 that the capacity INVPc of the inverter 102 is free, control is performed to increase the amount of generation QGP of the reactive power that is delayed as viewed from the photovoltaic power generation 100 side (step S29). . If it is determined in step S28 that the capacity INVPc of the inverter 102 is not empty, the process returns to step S22 and the process is continued.

If it is determined in step S27 that the voltage value Vt is greater than the threshold value VLP, then the reactive power adjuster 1033 determines whether or not the absolute value of the reactive power generation amount QGP is greater than zero. Performed (step S30). If it is determined in step S30 that the absolute value of the reactive power generation amount QGP is greater than 0, it is subsequently determined whether or not the power generation amount PGP is smaller than the power generation possible power PGPt (step S31). When it is determined in step S31 that the power generation amount PGP is smaller than the power generation possible power PGPt, control for increasing the power generation amount PGP is performed (step S32), and the process returns to step S22.
On the other hand, when it is determined in step S30 that the absolute value of the reactive power generation amount QGP is 0, control for increasing the absolute value of the reactive power generation amount QGP is performed (step S33), and thereafter, step S22. The process is continued after returning to.

[Another example of processing in the power generation output controller of the fuel cell]
Next, another example of voltage adjustment control in the fuel cell 300 will be described with reference to the flowchart of FIG. First, the threshold value VIF and threshold value VhF and parameters are set in the active power adjuster 3052 and the reactive power adjuster 3053 (see FIG. 7) (step S41), and then the voltage value Vt and the power load PL are detected by the detector 3051. It is measured (step S42). The threshold value VhF is a threshold value for preventing the voltage value Vt from deviating toward the upper limit of the management range, and is set to 106.5 V, for example.

  Next, the reactive power adjuster 3053 determines whether or not the voltage value Vt is greater than or equal to the threshold value VhF (step S43). If the voltage value Vt is greater than or equal to the threshold value VhF, it is subsequently determined whether or not there is a vacancy in the capacitor INVFc of the inverter 303 (step S44). If it is determined in step S44 that the capacity INVFc of the inverter 303 is free, control is performed to increase the amount of generation QGP of reactive power in phase as viewed from the fuel cell 300 side (step S45). Returning to S42, the processing is continued.

If it is determined in step S44 that the capacity INVFc of the inverter 303 is not empty, it is subsequently determined whether or not the power generation amount PGF is greater than the turn-down value PGFd (step S46). If it is determined that the power generation amount PGF is greater than the turndown value PGFd, control is performed to decrease the power generation amount PGF (step S47), and then the process returns to step S42 and the process is continued.
If it is determined in step S46 that the power generation amount PGF is less than the turndown value PGFd, the reactive power generation amount QGF is controlled to 0 (step S48), and the process returns to step S42 to continue the process. .

If it is determined in step S43 that the voltage value Vt is less than the threshold value VhF, it is next determined whether or not the voltage value Vt is equal to or less than the threshold value VlF (step S49). If it is determined in step S49 that the voltage value Vt is equal to or less than the threshold value VlF, it is subsequently determined whether or not the capacity INVFc of the inverter 303 is empty (step S50). If it is determined that the capacity INVFc of the inverter 303 is empty, control is performed to increase the amount of generation QGP of the reactive power that is late as viewed from the fuel cell 300 side (step S51), and then the process returns to step S42. Processing continues.
If it is determined in step S50 that the capacity INVFc of the inverter 303 is not empty, the process immediately returns to step S42 to continue the processing.

If it is determined in step S49 that the voltage value Vt is greater than the threshold value VIF, the reactive power adjuster 3053 then determines whether or not the absolute value of the reactive power generation amount QGF is greater than zero. Performed (step S52). If it is determined in step S52 that the absolute value of the reactive power generation amount QGF is greater than 0, control is performed to decrease the absolute value of the reactive power generation amount QGF (step S53), and then the process returns to step S42. Processing continues.
On the other hand, when it is determined in step S52 that the absolute value of the reactive power generation amount QGF is 0, it is determined whether or not the power generation amount PGF is smaller than the power load PL (step S54). If it is smaller than the power load PL, after the control to increase the power generation amount PGF is performed (step S55), the process returns to step S42 and the process is continued.
Similarly, when it is determined in step S54 that the power generation amount PGP is equal to or greater than the power load PL, the process returns to step S42 and is continued.

  Thus, by performing voltage adjustment control not only when the voltage drops but also when the voltage rises on the distributed power source side by the photovoltaic power generation 100 and the fuel cell 300, not only the effect obtained by the above-described embodiment, The effect that it becomes difficult to suppress the output of the photovoltaic power generation 100 due to the increase of the voltage value Vt is obtained.

  In the above-described embodiment, the case where the photovoltaic power generation 100 and the fuel cell 300 are combined as a distributed power source has been described as an example. However, the present invention is not limited to this. Even when a cogeneration system other than the fuel cell 300 such as a home gas engine or a device using other inverters and the solar power generation 100 are combined, the control similar to that of the fuel cell 300 described above in the cogeneration system and the inverter device. Needless to say, the same effect can be obtained if it is possible.

  5 ... Tap switching transformer at load, 5a ... Primary side tap winding, 5b ... Secondary side tap winding, 5d ... Movable contact, 5e ... Current limiting resistance, 5f ... Current collecting contact, 5g ... Current collecting conductor, 6 DESCRIPTION OF SYMBOLS ... Tap switching control part, 10c, 10r ... Pillar transformer, 100 ... Solar power generation, 101 ... Solar power generation cell, 102 ... Inverter, 103 ... Power generation output control part, 200 ... Load, 300 ... Fuel cell, 301 ... Hydrogen reformer 302 ... Fuel cell 303 ... Inverter 304 ... Waste heat recovery unit 305 ... Power generation output control unit 1031 ... Detector 1032 ... Active power regulator 1033 ... Reactive power regulator 1034 ... Current calculator, 1035 ... inverter output current regulator, 1036 ... amplifier, 1037 ... signal converter, 3051 ... detector, 3052 ... active power regulator, 3053 ... reactive power regulator, 054 ... Current calculator, 3055 ... Inverter output current regulator, 3056 ... Amplifier, 3057 ... Signal converter, INVFc, INVPc ... Capacity, Idc ... DC output current, It ... Current, PGF, PGP ... Power generation amount, PGFd ... Turn Down value, PL ... Power load, QGF ... Reactive power generation amount, QGP ... Reactive power generation amount, Vdc ... DC output voltage, VhF, VhP, VIF, VLP ... Voltage compensation start threshold, Vt ... Voltage value, f1, f2, f10 ... feeder, n1 to n9, n101 to n124, n201 to n214 ... node

Claims (7)

A distributed type including a distribution transformer that steps down the electric power received at an extra high voltage to a high voltage and supplies it to a plurality of consumers connected via a distribution line, and a distributed power supply device installed at the consumer In the power system,
The distribution transformer is:
A transformer that adjusts the delivery voltage of the distribution transformer based on a predetermined target voltage value;
When the distributed power supply device receives the delivery voltage adjusted according to the target voltage value, the voltage received by the distributed power supply device is low enough to deviate from the lower limit of a predetermined management range. A controller configured to set the target voltage value and control the transformer based on the set target voltage value;
The distributed power supply is
A power converter that converts predetermined energy into DC power;
An inverter that converts the DC power converted by the power conversion unit into AC power and outputs the AC power to the distribution line;
A detection unit for detecting a current and a voltage at a connection point with the distribution line;
When the active power and reactive power are detected from the current and voltage detected by the detection unit, and the voltage detected by the detection unit is equal to or lower than a preset threshold value, the power transformer is viewed from the distribution transformer. To output a reactive power of a leading phase, and generate a command signal for adjusting an output current of the inverter according to an output amount of the active power and an output amount of the reactive power, and the generated command signal is output to the inverter A power generation output control unit for supplying to,
Distributed power system. The value set by the control unit as the target voltage value, which is low enough to allow the voltage received by the distributed power supply device to deviate from the lower limit of a predetermined management range, is a value equal to or lower than the median value of the predetermined management range. The distributed power supply system according to claim 1. The distributed power supply device includes a photovoltaic power generation device and a fuel cell device,
The threshold value set in the power generation output control unit of the solar power generation device is set to a value higher than the threshold value set in the power generation output control unit of the fuel cell device.
The distributed power supply system according to claim 1 or 2. The advanced reactive power output by the power generation output control unit of the distributed power supply device is performed even in a state where the DC power cannot be obtained by the power conversion unit.
The distributed power supply system according to claim 1. Furthermore, it comprises a pole transformer that steps down the power supplied by the high voltage supplied from the distribution transformer to a low voltage and supplies it to the consumer,
Supply ratio to the customer in the position near the distribution transformer and the transformation ratio in the pole transformer for supplying electric power to the customer in the position away from the distribution transformer The transformation ratio in the pole transformer to be set to an equivalent ratio,
The distributed power supply system according to claim 1. In the power generation output control unit of the distributed power supply device, a second threshold value that is larger than the threshold value is set,
When the voltage detected by the detection unit is greater than or equal to the second threshold value and the capacity of the inverter is vacant, the power generation output control unit is advanced as viewed from the distributed power supply device. Outputs reactive power,
The distributed power supply system according to claim 1. A power converter that converts predetermined energy into DC power;
An inverter that is connected to a distribution line connected to a power system, converts the DC power converted by the power conversion unit into AC power, and outputs the AC power to the distribution line,
A detection unit for detecting a current and a voltage at a connection point with the distribution line;
Generating a command signal for adjusting the output current of the inverter, and supplying the generated command signal to the inverter, and a power generation output control unit,
The power generation output controller is
Based on the current and voltage detected by the detector, the active power and reactive power supplied from the inverter to the distribution line are detected,
When the voltage detected by the detection unit is equal to or lower than a preset threshold value, the reactive power of the leading phase is output as viewed from the distribution transformer connected to the distribution line,
According to the output amount of the active power and the output amount of the reactive power, a command signal for adjusting the output current of the inverter is generated.
A distributed power supply device.

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