JP2002374629A - Received power regulating device, private power generating device, and method of controlling them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly reduce the output of a generator, even if power is supplied according to change in load and to efficiently utilize the supplied power for abnormality detection, etc. SOLUTION: A private power generating device 11 controls a generator 12 by a received power regulating device 13 to keep a received power constant for the system interconnection with a commercial power supply. When load is reduced suddenly, power is stored in a capacitor 20. As the power for charging the capacitor 20 is excluded from a received power for controlling the generator 12, the output of the generator 12 can be controlled quickly. If the power stored in the capacitor 20 is supplied to an important load, a high reliability uninterrupted power supply can be constituted as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power receiving power adjusting device for controlling a power receiving power to a predetermined value or more when a private generator is connected to a commercial power supply so as to prevent reverse power flow. And a private power generator and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, when a power generator for private use such as a cogeneration system is connected to a commercial power supply and grid connection is performed, at present, generally there is no reverse power, that is, the power output from the generator. The operation is performed without supplying the power to the commercial power supply. The reason for using a private generator and a commercial power supply together is to set the capacity of the generator so as to increase the efficiency in consideration of the load frequency, etc., and to replenish the insufficient power from the commercial power supply. . Although the output of the generator is controlled according to the load, it is difficult to sufficiently follow a sudden change in the load. For this reason, when the load suddenly decreases, the output of the generator exceeds the load, and a reverse power flow to the commercial power supply is likely to occur.

[0003] Fig. 11 shows a concept of a generally-received power control that is generally performed in order to prevent reverse power flow. In this control, control is performed in which electric power of a certain value or more is supplied from the commercial power supply to the premises of the generator installer. When the load power increases, the power exceeding the maximum output of the generator is supplied from the commercial power supply. Since the load fluctuation in the premises where the generator is installed is steep, when the load decreases sharply, the output control of the generator may not be able to follow as described above, and the output of the generator may exceed the load. There is. In order to avoid the possibility that power flows to the commercial power supply side during such a load change, power monitoring is performed at a power receiving point, and power of a certain value or more is received from the commercial power supply to the premises. Excessive excess power until the output of the generator follows the decrease in load is absorbed within the range of the fixed value of power, and reverse power flow can be prevented.

Japanese Patent Application Laid-Open No. 10-150483 discloses that a flywheel generator motor absorbs power when the load power suddenly decreases and the flywheel generator motor functions as a generator when the load power increases rapidly. The prior art that makes the load fluctuation equalize is disclosed.

FIG. 12 shows that when a private generator is used in combination with a commercial power supply, a power failure of the commercial power supply is detected to disconnect the generator and the load connected to the generator as a countermeasure in the event of an abnormality in the commercial power supply. 1 shows a schematic configuration of a private power generator 1 that can be separated. In the private power generator 1, the loads of the generator 2 are grouped into important loads 3 and general loads 4. The important load 3 is directly connected to the generator 2, and the general load 4 is connected from the generator 2 via a circuit breaker 5. The generator 2 has a commercial power source 6
The general load 4 is connected to the commercial power supply 6 side.
However, an interconnecting circuit breaker 7 is connected between the generator 2 and the important load 3, and a power receiving circuit breaker 8 is connected between the commercial power supply 6 and the general load 4. The voltage of the commercial power supply 6 is detected by the power failure detection device 10 via the transformer 9, and when an abnormality such as a power failure occurs, a shutdown command is given from the power failure detection device 10 to the circuit breaker 5 to open the circuit breaker 5. Control is performed. By opening the circuit breaker 5, the general load 4 is disconnected from the output of the generator 2, and power supply can be continued with only the important load 3 as the load of the generator 2.

[0006]

When the above-described constant received power control is performed, even when the load fluctuation is small and the load is relatively stable, the generator output supplied to the load is limited to a constant received power. Must be reduced and generator output is limited. For this reason, problems such as a decrease in the load factor / operating rate and a decrease in the power generation efficiency occur.

When the amount of load fluctuation is large, it is necessary to increase the fixed amount of received power. For this reason, only small generators can be selected at the stage of capacity selection at the stage of capacity selection, and it is impossible for cogeneration systems, etc., to select the capacity that is considered optimal in terms of balance with heat output. Will be.

In the prior art of Japanese Patent Application Laid-Open No. 10-150483, as described in the first half of the paragraph [0018], “the received power leveling device 10 Energy reserves,
The configuration and operation relating to "absorb instantaneously by firing" are described in relatively detail. However, nothing is described in the latter half of the paragraph [0018] regarding "working to slowly shift invariable components to the private generator 2 side". The control of the in-house generator 2 is the same as that of the prior art shown in FIG. 4 of the official gazette, and as described in the paragraph [0002], the automatic load controller 6 controls the load based on the received power value. It is considered that the setting device 7 is adjusted. In FIG. 1 of the publication, no output from the received power leveling device 10 is given to the automatic load controller 6. Therefore, when the load decreases and the surplus power is absorbed by the received power leveling device 10, the received power serving as an input to the automatic load controller 6 has no apparent fluctuation, and the private power generation is performed. Control of the output reduction of the power generator 2 is delayed, and the power absorbed by the received power leveling device 10 is continuously supplied from the private power generator 2.

Further, in the countermeasure against the abnormal situation of the commercial power supply as shown in FIG. 12, it is possible to make the important load 3 uninterrupted by using the generator 2.
A voltage drop occurs during the time when the breaker 5 is disconnected after the abnormality is detected.

SUMMARY OF THE INVENTION It is an object of the present invention to quickly reduce the output of a generator even if power is absorbed in response to a change in load, and to make effective use of the absorbed power when an abnormality is detected. It is an object of the present invention to provide a received power adjustment device, a private power generation device, and a control method therefor.

[0011]

SUMMARY OF THE INVENTION According to the present invention, when a private generator is connected to a commercial power supply by system interconnection, reverse power flow is prevented, and when the load is small, the output of the private generator is suppressed. In a power receiving power control device that constantly controls to receive power of a certain amount or more, a power storage unit capable of storing and releasing power output from a private generator when a load suddenly decreases, A power generation control unit that controls the output of the generator based on the received power excluding the power stored in the power storage unit.

According to the present invention, the power receiving power control apparatus suppresses the reverse power flow when the private power generator is connected to the commercial power supply in a system connection, and suppresses the output of the private power generator when the load is small. In order to perform control so as to always receive a predetermined amount or more of power, the power storage unit and the power generation control unit are included. The power storage means is capable of storing and discharging power output from the private power generator when the load suddenly decreases. As the power storage means, for example, a power storage unit that stores power using electric charges such as a capacitor or a battery, or a mechanism that converts power into kinetic energy and stores it, such as a flywheel, can be employed. The power generation control means
Since the output of the private power generator is controlled based on the received power excluding the power stored in the power storage means, the received power excluding the power absorbed by the power storage means must be equal to or more than a certain amount when the load suddenly decreases. With this control, the power generation output can be quickly reduced following the decrease in load.

In the present invention, the power storage means has a capacity capable of storing power in a range previously set as a minute load fluctuation, and a power consumption capable of consuming excessive power exceeding the range. It is characterized by further comprising means.

According to the present invention, the capacity of the power storage means is
It is possible to store power in a range that is set in advance as a minute load fluctuation at all times as a storable value, and excess power exceeding this range can be consumed by the power consuming means. By setting the frequency of storage and release to be high, the expensive power storage means can be used efficiently. For example, for infrequent and excessive power generation, such as a steep load change of a load that uses large power such as an electric furnace, the power is consumed by a power consumption means such as a resistor, and the reverse power flow is ensured. Can be prevented. Since it is not necessary to use a large-capacity power storage means, the cost can be reduced.

Further, the present invention is characterized in that it further comprises a storage power supply means capable of directly supplying the power stored in the power storage means to a load.

According to the present invention, the power stored in the power storage means can be directly supplied to the load by the stored power supply means, so that the power storage means can be used in the event of an abnormality such as a power failure of a commercial power supply or a private generator. It can be used as an uninterruptible power supply, and can always supply power stably to important loads. Since it is combined with a private generator, the capacity of the power storage means can be extremely reduced as compared with a normal uninterruptible power supply.

[0017] The present invention further provides a private power generator comprising: the power receiving control device according to any one of the foregoing; and a generator whose output is controlled by power generation control means of the power receiving power adjusting device. is there.

According to the present invention, the received power adjusting device quickly controls the output of the generator while absorbing the excess power generated from the generator when the load suddenly decreases, thereby enabling the self-power generation. Efficiency and reliability can be increased.

Further, the present invention is connected to a commercial power supply in a system-interconnected manner, and in order to prevent reverse power flow, while controlling so as to always receive a certain amount or more of power even when the load is small, the output of the generator is controlled. In the control method of the private power generator for controlling the power generation means, in the output of the generator, the power output from the generator at the time of a sudden decrease of the load is stored, and the power storage means capable of discharging the stored power to the load Is connected, and the output of the generator is controlled based on the received power excluding the power stored in the power storage means.

According to the present invention, when the generator is connected to a commercial power supply in a system interconnection, the output of the generator is suppressed even when the load is small, and the power of a fixed amount or more is always maintained even when the load is small. Control to receive power. Since it is possible to store and absorb the power output from the generator in the power storage means when the load suddenly decreases, a certain amount of received power required to reliably prevent reverse power flow is reduced, The load factor and operation rate of the generator can be improved.

Further, the present invention is characterized in that the power stored in the power storage means is supplied to a preset important load.

Since the charge stored in the power storage means used for adjusting the received power is supplied to the important load, even if the output of the commercial power supply or the generator is reduced, the load is not applied to the important load. Power supply can be reliably continued without interruption.

[0023]

FIG. 1 shows a schematic electric configuration of a private power generator 11 according to a first embodiment of the present invention.
The private power generation device 11 uses the received power adjustment device 13 in order to prevent reverse power flow when the power generator 12 is connected to a commercial power supply by system interconnection. The received power adjustment device 13 controls the output of the generator 12 when the load is small, and controls to always receive a certain amount or more of power from the commercial power supply. A commercial power supply and the output of the generator 12 are connected to the premises wiring line 14 of the installer of the generator 12, and power is supplied to loads and important loads.

In the received power adjusting device 13, the power input / output unit 15, the received power value input unit 16, the commercial abnormal signal input unit 1
7, and the received power value output unit 18 can be used for input or output with the outside. Received power value output unit 1
The control output from the control unit 19 is derived to 8 and used for controlling the generator 12. The accumulation and release of power while the generator 12 is unable to follow steep load changes,
This is performed by the capacitor 20 as the power storage means. The power stored and released in the capacitor 20 is calculated by the power calculator 21. The operating power of each unit in the received power adjusting device 13 such as the control unit 19 is controlled by the control power supply unit 2.
Supplied from 2. Since the capacitor 20 accumulates electric charges, the accumulated electric power needs to be converted from AC to DC by the AC / DC converter 23. The AC / DC conversion unit 23
When discharging the electric charge stored in the capacitor 20, direct current can be converted to alternating current.

Power input / output unit 15 and AC / DC converter 23
Between the circuit breaker 24, the current transformer 25, and the transformer 2
6 are provided. The current transformer 25 and the transformer 26 are AC
A voltage value and a current value charged or discharged to / from the capacitor 20 via the / DC converter 23 are detected. The voltage value and the current value detected by the current transformer 25 and the transformer 26 are input to the power calculation unit 21, and the power value is calculated as a product of the voltage value and the current value. The power value to be charged / discharged to / from the capacitor 20 from the power calculation unit 21 is input to the control unit 19, and the power is received from the commercial power supply to the premises wiring line 14 and converted into the power value by the power converter 27. The power value is input via the received power value input unit 18.

The power converter 27 is disposed at a portion where the local wiring line 14 is connected from the commercial power supply via the first circuit breaker 28, and detects the received power. The received power adjustment device 13 and the important load, and the generator 12
Is connected to the first circuit breaker 28 through the circuit breaker 29 of FIG.
Insignificant loads include the first breaker 28 and the second breaker 2
9 is connected.

FIG. 2 shows a control procedure of the control unit 19 in the embodiment of FIG. The procedure starts from step a0, and in step a1, it is determined whether or not an abnormality such as a power failure has occurred in the commercial power supply. Whether or not an abnormality such as a power failure has occurred in the commercial power supply may be determined using a power failure detection device 10 or the like as shown in FIG. 12 and a commercial abnormality signal indicating the determination result may be used. When it is determined in step a1 that an abnormality has occurred in the commercial power supply, the control of the present apparatus is temporarily stopped, and in step a2, it is waited for the commercial power supply to recover from the abnormality. If it is determined in step a1 that no abnormality has occurred in the commercial power supply, or if it is determined in step a2 that the commercial power supply has recovered from the abnormality, the process proceeds to step a3.

In step a3, the received power value input unit 13
The received power value E input from the controller 20 and the capacitor 20 calculated by the power calculator 21 in the received power adjustment device 13
And the input / output power value F to the power supply. The input / output power value F is positive (+) on the input side. In the control unit 19, the power converter 2
7 and the input / output power value F calculated by the power calculator 21 as a difference between the input / output power F to the capacitor 20 and the net received power value E0. = E−F. The received power value E0 as a calculation result is used in the received power adjustment device 13 and is output from the received power value output unit 18 as a control input of the generator 12. The received power value E0 is compared with a target value M of the received power. If E0 has decreased to less than M, that is, if E0 <M, the process proceeds to step a4, where electric power is charged based on the calculation of M-E0, and power corresponding to M-E0 is absorbed by the capacitor 20, and Return to a3. In addition,
The received power adjustment device 13 of the present embodiment has a function that can arbitrarily set the target value M from the outside.

If it is determined in step a3 that E0 <M is not satisfied, the process proceeds to step a5, in which the received power value E0 exceeds the constant received power control value K of the generator 12, and whether E0> K is satisfied. Judge. When the received power value E0 exceeds the received power constant control value K, in step a6,
The electric power charged in the capacitor 20 is discharged within the range of E0-K and supplied to the load together with a part of the generated electric power. When step a6 ends, or when it is determined that E0> K is not satisfied in step a5, the process returns to step a1 and a series of procedures is repeated.

In the received power adjusting device 13 of the present embodiment,
Since the adjustment of the received power is performed by charging or discharging the capacitor 20, an extremely high following speed can be realized as compared with the case where only the adjustment of the generated power of the generator 12 is performed. As a result, the received power value E0 can be reduced as the capacity of the received power adjusting device 13 increases, which can contribute to the improvement of the load factor and the operation rate of the generator 12.

FIG. 3 shows a schematic electrical configuration of a private power generator 31 according to a second embodiment of the present invention. In the present embodiment, portions corresponding to the embodiment of FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted. In the present embodiment, the flywheel 40 is incorporated in the received power adjusting device 33 as power storage means capable of storing and discharging power output from the generator 12 when the load suddenly decreases. The flywheel 40 rotates as a rotor of an AC motor and an AC generator, and can store and discharge electric power as kinetic energy. For driving the flywheel 40, a DC / AC converter 41 is added, and its control signal line is also added. The DC / AC conversion unit 41 is an AC / D converter.
The DC converted by the C converter 23 is converted into an AC whose frequency is further converted. The operation of this embodiment is basically the same as the embodiment of FIG.

On the output side of the AC / DC converter 23, FIG.
Are also connected. Regarding the sharing of the stored power in the received power adjusting device 33 of the present embodiment, since the loss of the capacitor 20 is smaller, the charge and discharge of the capacitor 20 is prioritized, and the excess of the capacity of the capacitor 20 is considered. The flywheel 40 is charged and discharged. In addition, even if there is no capacitor 20 for power storage, it can operate as the received power adjusting device 33. In addition, the capacitor 20
Instead of the flywheel 40 and the flywheel 40, another power storage unit such as a battery can be used as the power storage unit.

FIG. 4 shows a schematic electric configuration of a private power generator 51 according to a third embodiment of the present invention. In the present embodiment, portions corresponding to the embodiment of FIG. 1 or FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted. The received power adjustment device 53 of the present embodiment is different from the received power adjustment device 3 of FIG.
3 has a configuration in which a resistor section 60 and a switch 61 are combined. In the embodiment shown in FIGS. 1 and 3, relatively small adjustment of the received power is sufficiently possible. However, in the case where it is intended to cope with a stop of a load using a large amount of power such as an electric furnace, Therefore, a large-capacity power storage unit corresponding to this is required. Such a shutdown of a large-capacity electric furnace or the like occurs at an extremely low frequency as compared with a minute load change due to temperature adjustment or the like. If a low-capacity power storage unit is used at a low frequency, the cost increases. Therefore, economical charging / discharging is performed using a power storage unit for relatively small load fluctuations, and charging / discharging by a power storage unit is performed for steep load fluctuations exceeding the charging / discharging unit. A configuration that consumes power is adopted.

FIG. 5 shows a control procedure of the control unit 19 in the embodiment of FIG. The procedure from step b0 to step b3 is equivalent to each step from step a0 to step a3 in FIG.

When it is determined in step b3 that E0 <M, the process proceeds to step b4, where the value of M-E0 is compared with the total capacity C of the power storage unit. The total capacity of the power storage unit is calculated by summing the capacitance of the capacitor 20 and the capacity conversion value of energy that can be stored in the flywheel 40. Result of comparison C
If it is not <M−E0, since all control can be performed only by the power storage unit, power is absorbed in step b5 in the same manner as step a4 in FIG. 2, and the process returns to step b3. Step b4
When it is determined that C> M−E0, in steps b6 and b7, the power is stored in the power storage unit up to the amount of C, and for the portion exceeding this (M−E0) −C, step b
At 8, the switch 61 of the resistor 60 is turned on and consumed. In step b9, the switch 61 is operated to
The resistors 60 are sequentially disconnected. When a steep load change occurs, the output of the generator 12 is reduced by the received power constant control, so that the resistor 60 is sequentially disconnected based on the value of E0-K.

FIG. 6 shows a control state for charging the power storage unit in step b7 of FIG. After charging starts, time t
Until 0 elapses, the capacity of C is stored. Time t0
Is set in consideration of the tracking delay of the generator 12. Time t
After the lapse of 0, C / (t
According to the gradient of 0-t1), the charged amount is reduced. Here, the slope C / (t0−t1) is set to be equal to or less than the following speed of the generator 12.

When step b7 and step b9 in FIG. 5 are completed, it is determined in step b10 whether E0> K. Only when it is determined that E0> K, in step b11, as in step a6 in FIG. 2, the stored power is discharged, and the process returns to step b1.

FIGS. 7, 8 and 9 show an in-house power generator 6 according to the fourth, fifth and sixth embodiments of the present invention.
1, 71 and 81, in addition to the configuration of the received power adjusting devices 13, 33 and 53 in the embodiment of FIGS. 1, 3 and 4, a DC / AC converter 65 and a stable power output unit 66 Configurations including the power adjusting devices 63, 73, and 83 are shown, respectively. The most important load that supplies power without interruption is connected to the stable power output unit 66.

FIG. 10 shows a control procedure common to the embodiments of FIGS. 7, 8 and 9. Step c0 and step c1 are respectively equivalent to step b0 and step b1 in FIG. In Step c2, the reception power adjustment function is stopped, and in Step c3, the Uninteruptable Power Sys
The function as an uninterruptible power supply, abbreviated as UPS, is started from tem. Each step from step c4 to step c13 is equivalent to each step from step b2 to step b11 in FIG. That is, if an abnormality has occurred in the commercial power supply in steps c1 to c4, the UPS function using the power storage unit of the received power adjustment devices 63, 73, and 83 is operated.
This is because, when an abnormality occurs in the commercial power supply, the circuit breaker 29 is disconnected in FIGS. 7 to 9 and the generator 12 is disconnected from the commercial power supply, so that the received power adjustment is not required,
This is because a stable power supply is required for the most important loads. All the energy stored in the power storage unit can be used for the most important load.

For this purpose, it is preferable that the capacitor 20 and the power storage unit of the flywheel 40 always store a certain amount of energy or more. Therefore, in step c13 of charging power release, it is necessary to leave not less than a certain amount of energy instead of releasing all charging energy. This is because in order to supply stable power to the most important load, it is necessary as backup energy until the disconnection of the breaker 29 is completed. However, as described above, this backup energy is continuously operated by disconnecting the generator 12 from the commercial power supply when an abnormality occurs in the commercial power supply, and the received power adjusting devices 63, 73, 83
It is possible to continuously supply power to
As compared with a general UPS device, it is possible to cope with very few devices.

[0041]

As described above, according to the present invention, it is possible to reduce the control value of the received power constant control when the private generator is connected to the commercial power supply under system without reverse tide. As a result, the load factor and the operation rate of the generator can be improved. The power is adjusted using power storage means that can store and release the power output from the private generator when the load suddenly decreases, etc. And can be reused, so that the loss of effective power energy can be reduced.

Further, according to the present invention, for a steep load change of a load using a large amount of power such as an electric furnace, for example, excess power is consumed by a power consuming means such as a resistor. Therefore, it is not necessary to use a large-capacity power storage means, and cost can be reduced.

Further, according to the present invention, the power storage means can be used as an uninterruptible power supply for important loads. Since it is combined with a private generator, the capacity of the power storage means can be extremely reduced as compared with a normal uninterruptible power supply.

Further, according to the present invention, while absorbing the extra power generated from the generator when the load suddenly decreases,
Control for lowering the output of the generator can be quickly performed, and the efficiency and reliability of private power generation can be improved.

Further, according to the present invention, when a generator is connected to a commercial power supply in a system-connected manner, in order to prevent reverse power flow, when performing control to constantly receive a certain amount or more of power, In the case of a rapid decrease in the power, the excess power output from the generator is stored and absorbed in the power storage means, so that a certain amount of received power can be reduced, and the load factor and operating rate of the generator can be improved. .

Further, according to the present invention, the generator and the power storage means are combined to perform stable power supply to an important load without interruption, and the capacity of the power storage means is reduced to reduce the cost. be able to.

[Brief description of the drawings]

FIG. 1 shows a private power generator 1 according to a first embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 2 is a flowchart showing a control procedure of the embodiment of FIG.

FIG. 3 shows a private power generator 3 according to a second embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 4 shows a private power generator 5 according to a third embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 5 is a flowchart showing a control procedure of the embodiment of FIG.

FIG. 6 is a graph showing the concept of controlling the amount of stored electricity in step b7 of FIG.

FIG. 7 shows a private power generator 6 according to a fourth embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 8 shows a private power generator 7 according to a fifth embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 9 shows a private power generator 8 according to a sixth embodiment of the present invention.
FIG. 1 is a block diagram showing a schematic electrical configuration of FIG.

FIG. 10 is a flowchart illustrating a control procedure according to the embodiment of FIG. 9;

FIG. 11 is a graph showing a conventional concept of the received power constant control.

FIG. 12 is a block diagram showing a conventional electrical configuration for avoiding a critical load power failure when a commercial power supply fails.

[Explanation of symbols]

11, 31, 51, 61, 71, 81 In-house power generator 12 Generator 13, 33, 53, 63, 73, 83 Power reception adjusting device 19 Control unit 20 Capacitor 21 Power calculation unit 23 AC / DC conversion unit 24, 28 , 29 Circuit breaker 40 Flywheel 41, 65 DC / AC conversion unit 60 Resistor 61 Switch 66 Stable power output unit

Claims (6)

[Claims] 1. When a private generator is connected to a commercial power supply by system interconnection, the output of the private generator is suppressed when the load is small to prevent reverse power flow, and power of a certain amount or more is always received. A power storage device that can store and release the power output from the private generator when the load suddenly decreases, and a power storage device that stores the output of the private generator. And a power generation control means for controlling based on the received power excluding power stored in the means. 2. The power storage means has a capacity capable of storing power in a range previously set as a minute load fluctuation, and further includes a power consumption means capable of consuming excessive power exceeding the range. The power receiving power adjusting device according to claim 1, further comprising: 3. The power stored in the power storage means,
3. The received power adjusting device according to claim 1, further comprising a storage power supply unit that can directly supply the load to a load. 4. A private power generator comprising: the power receiving control apparatus according to claim 1; and a generator whose output is controlled by power generation control means of the power receiving control apparatus. . 5. The output of the generator is connected to a commercial power supply in a system-interconnected manner, and controls the generator so as to always receive at least a certain amount of power even when the load is small, in order to prevent reverse power flow. In the control method of the private power generator, a power storage means capable of storing power output from the generator when the load suddenly decreases and discharging the stored power to the load is connected to the output of the generator. In addition, a control method of the private power generator, wherein the output of the generator is controlled based on the received power excluding the power stored in the power storage means. 6. The power stored in the power storage means,
The control method for a private power generator according to claim 5, wherein the power is supplied to a preset important load.