JP2007282390A - Current-monitoring reactive power adjustment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a current-monitoring reactive power adjustment device capable of inhibiting voltage fluctuations by effectively adjusting reactive power even if a load disperses. <P>SOLUTION: A first to an N-th reactive power adjustment devices 10<SB>1</SB>to 10<SB>N</SB>respectively connected to a first to an N-th inverter power supplies 21<SB>1</SB>to 21<SB>N</SB>performs phase lag operation control or phase advance operation control by prioritizing an inverter power supply 21<SB>1</SB>on the end side of a distribution line 2 based on distribution line current input from a first to an N-th current transformers 4<SB>1</SB>to 4<SB>N</SB>so as to adjust reactive power. For example, a first inverter power control section 13<SB>1</SB>of the first reactive power adjustment device 10<SB>1</SB>performs phase lag operation control or phase advance operation control for the first inverter power supply 21<SB>1</SB>so as to reduce distribution line current input from the first current transformer 4<SB>1</SB>upon receiving the determination result from the first control code determination section 12<SB>1</SB>that other inverter power supplies 21<SB>2</SB>to 21<SB>N</SB>with higher priority are not under control. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a current monitoring reactive power adjustment device, and more particularly to a current monitoring reactive power adjustment device suitable for adjusting reactive power that causes voltage fluctuations in a distribution line.

  In general, a power factor improving capacitor (SC) is installed in a high-voltage power receiving facility to compensate for the late phase reactive power of the load under heavy loads, but the power factor improving capacitor at light loads such as at night If they are left unconnected, the voltage at the end of the distribution line rises due to the ferrant effect.

  Conventionally, in order to prevent the voltage rise at the end of the transmission line due to such a ferrant effect, the voltage is appropriately adjusted by a transformer tap at an electric station, or at a light load by using a shunt reactor (Shr: Shunt Reactor) Compensating for the fast phase reactive power of the load at

  In addition, in the following Patent Document 1, in order to suppress the output power of the distributed power source that is connected to the power system from being greatly hunted to maintain the connection point voltage at a constant value, a predetermined value is set. When the lower limit value is set below the upper limit value (or limit value) of the interconnection point voltage and the interconnection point voltage is between these upper limit value and lower limit value, the phase advance of the distributed power supply is disabled Continues control to reduce active power while maintaining power factor at 85% with power control, and returns to normal operating state in which maximum power is output at 100% power factor when the connection point voltage falls below the lower limit. A method for controlling a distributed power source connected to a power system is disclosed.

Further, in Patent Document 2 below, in order to improve the power factor of the load with respect to the commercial power source of the uninterruptible power supply to “1”, to suppress the harmonic current, and to further suppress the ferrant effect at light load. In an uninterruptible power supply that normally supplies AC power from a commercial power supply to the load via an AC switch and supplies the AC power from the storage battery to the load from the inverter main circuit when the commercial power supply fails, the inverter control circuit A control method is disclosed in which a value obtained by detecting a load current with a current detector and a value obtained by detecting a filter capacitor current with a current detector are inputted and controlled, and a gate signal is given to an inverter main circuit.
JP-A-8-280136 JP-A-7-219660

However, in recent years, the voltage rise at the end of the distribution line due to the late-night ferrant effect has increased, and in the voltage adjustment by the transformer tap and compensation of the phase reactive power using the shunt reactor as described above, the end of the distribution line is increased. However, there is a problem that a large line loss due to compensation power is generated.
In order to adjust the reactive power, it is most effective to install a power factor adjustment device (active filter) near the load that generates the reactive power. There is a problem that it is very difficult to take such measures.

  An object of the present invention is to provide a current monitoring type reactive power adjusting device capable of suppressing voltage fluctuation by effectively adjusting reactive power even when a load is distributed.

The current monitoring reactive power adjusting device of the present invention is connected to a plurality of inverter power supplies (21 _{1 to} 21 _N ) distributed on a distribution line (2) branched from a bus (1), based on the distribution line current input from a plurality of current transformers in the vicinity of the inverter power supply of the plurality of distribution line are distributed respectively (4 ₁ ~4 _N), it is disposed distally of the該配wire A current monitoring type reactive power adjustment device (10 ₁ to 10 _N ) for adjusting reactive power by performing slow phase operation control or phase advance operation control with priority over the inverter power source, and other inverter power sources are under control Control code determination means (12 _{1 to} 12 _N ) for checking whether or not the priority of the other inverter power supply under control is high, and from the control code determination means, Other larger When the determination result indicating that the barter power supply is not under control is received, the distribution line current input from the current transformer disposed in the vicinity of the inverter power supply to which the current monitoring reactive power adjustment device is connected is reduced. And an inverter power source control means (13 _{1 to} 13 _N ) for performing a slow phase operation control or a phase advance operation control of the inverter power source.
Here, the plurality of inverter power supplies are prioritized by a priority address in which the numerical value increases in the order of the inverter power supply arranged on the terminal end side of the distribution line to the inverter power supply arranged on the tip end side of the distribution line. May be.
The inverter power supply control means includes a control code including a control status code indicating whether or not the inverter power supply controlled by the inverter power supply control means is under control and a priority address code indicating the priority address of the inverter power supply. The pulse phase advance control corresponding to the control status code and the pulse phase advance control corresponding to the priority address code may be performed on the inverter power supply.
Whether or not the voltage of the inverter power supply controlled by the inverter power supply control means is within an appropriate range by determining whether or not there is a possibility of deviating from an appropriate value from a predetermined voltage fluctuation rate of the inverter control based on the commercial voltage. or to determine the determination results may further include a voltage determining means for notifying (16 ₁ ~16 _N) to the inverter power supply control means.

Said plurality of inverter power supply further comprising state flag state flag memory for storing _{(C k) (15 1 ~15} N) of the inverter power the inverter power supply control means, controlled by the inverter power source control means When the slow-phase operation control or the phase-advance operation control is performed, it is checked whether or not the distribution line current has decreased within a predetermined range, and the distribution line current has decreased only within the predetermined range. May determine the state flag of the inverter power supply in the slow phase operation direction or the phase advance operation direction, and store the determined state flag in the state flag memory.
When the inverter power supply control means performs slow phase operation control or phase advance operation control on the inverter power supply controlled by the inverter power supply control means, the direction opposite to the previous operation control direction based on the state flag Alternatively, slow phase operation control or phase advance operation control may be performed.
The inverter power source control unit further comprises a control count memory for storing the control count _{(P) (14 1 ~14 N} ) input from the inverter power supply control unit is controlled by the inverter power source control means If reactive power cannot be adjusted even if one of slow-phase operation control and phase-advance operation control is performed on the inverter power supply, the control count stored in the control count memory is read, and the read control count Is not "1" or more, "1" is added to the control count and stored in the control count memory, and then the other of the slow phase operation control and the phase advance operation control is performed, and the read control count is "1" or more When a certain rest time has elapsed, the control count is set to “0” after the lapse of a certain rest time, based on the control code. The operation control direction may be performed with the slow operation control or the phase advance operation control in the opposite direction.
The inverter power supply includes a rectifier (51 _{1 to} 51 _N ), a storage battery (52 _{1 to} 52 _N ) connected to the rectifier, and an inverter (53 _{1 to} 53 _N ) connected to the rectifier and the storage battery. It is also possible to store electric power in the storage battery when there is surplus electricity at midnight, and to supply reactive power from the storage battery when there is insufficient daytime electricity.

  As shown in FIG. 7, the current monitoring reactive power adjustment device of the present invention uses the principle that when the power factor improves and the reactive power decreases, the distribution line current also decreases, so that the distribution line current decreases most. Therefore, the reactive power can be effectively adjusted even when the load is distributed.

  The above-mentioned object is realized by performing slow-phase operation control or phase-advance operation control from the end with respect to a plurality of inverter power supplies distributed in the distribution line so that the distribution line current of the distribution line decreases. .

Embodiments of the current monitoring reactive power adjustment device of the present invention will be described below with reference to the drawings.
First to Nth current monitoring reactive power adjustment devices 10 ₁ to 10 _N (hereinafter referred to as “ _first to _Nth reactive power adjustment devices 10 ₁ to 10 _N ”) according to an embodiment of the present invention. As shown in FIG. 1, they are connected to _{first to Nth} inverter power supplies 21 _{1 to} 21 _N such as solar cells distributed on a distribution line 2 branched from a bus 1.
Here, the first to Nth inverter power supplies 21 _{1 to} 21 _N operate independently under the control of the _first to _Nth reactive power adjustment devices 10 ₁ to 10 _N , respectively, but are controlled by one inverter power supply. Since the influence of (slow-phase operation control or phase-advance operation control) extends to other inverter power supplies, the first to N-th reactive power adjustment devices 10 ₁ to 10 _N each have a constant value when starting control. After a rest time (for example, 1 minute) elapses, it is confirmed that another inverter power source is not under control.

In addition, the first to Nth reactive power adjustment devices 10 ₁ to 10 _N are distributed in the vicinity of the _{first to Nth} inverter power supplies 21 _{1 to} 21 _N of the distribution line 2, respectively. Based on the secondary current (hereinafter referred to as “distribution line current”) of the current transformers (CT) 4 ₁ to 4 _N , the _first to _N- th inverter power supplies 21 _{1 to} 21 _N are respectively assigned according to priority. Reactive power is adjusted by slow-phase operation control or phase-advance operation control.
For this reason, the first to N-th inverter power supplies 21 _{1 to} 21 _N perform control preferentially from the terminal side of the load (terminal side of the distribution line 2), so that the terminal side (most bus 1) of the distribution line 2 is controlled. Priority is given to the priority address in which the numerical value increases in the order from the first inverter power supply 21 ₁ arranged on the far side) to the Nth inverter power supply 21 _N arranged on the distal end side (most bus 1 side) of the distribution line 2 Has been ranked.

The first reactive power adjuster 10 ₁ includes a first current decrease determination unit 11 _1, the first control code judging unit 12 _1, a first inverter power source control unit 13 _1, the first control count memory 14 includes _1, the first state flag memory 15 _1, a ₁ and a first voltage determination unit 16.

The first current increase / decrease determination unit 11 ₁ determines the increase / decrease of the distribution line current based on the distribution line current from the _first current transformer 4 ₁ and extracts the control code.
The control codes are generated by the _first to _N- th inverter power control units 13 _{1 to} 13 _N of the _first to _N- th reactive power adjustment devices 10 ₁ to 10 _N , and as shown in FIG. Including a priority address code. The control status code indicates whether or not the first to N-th inverter power supplies 21 _{1 to} 21 _N are under control (during slow-phase operation control or phase-advance operation control), or other inverters under control This is for stopping the operation control of the power source. The priority address code is for indicating the priority address of the _{first to Nth} inverter power supplies 21 _{1 to} 21 _N.
In addition, as shown in FIG. 2, the first to Nth inverter power supply control units 13 _{1 to} 13 _N correspond to the control status codes for the _{first to Nth} inverter power supplies 21 _{1 to} 21 _N as shown in FIG. By performing the pulse phase advance control and the pulse phase advance control corresponding to the priority address code, respectively, the reactive power is output to the distribution line 2 before the reactive power by the slow phase operation control or the phase advance operation control.

The first control code determination unit 12 ₁ uses other inverter power sources (second to second) based on the control state code and the priority address code included in the control code extracted by the _first current increase / decrease determination unit 11 ₁ . Whether or not the Nth inverter power supply 21 _{2 to} 21 _N ) is being controlled and its own inverter power supply (first inverter power supply 21 ₁ ) is another inverter power supply ( _second to Nth inverter power supplies 21 ₂ to 21 N It is determined whether the priority is higher than 21 _N ), and the determination result is notified to the _first inverter power supply control unit 131.

The first inverter power supply control unit 13 ₁ includes the distribution line current input from the first current increase / decrease determination unit 11 _{1, the} determination result notified from the first control code determination unit 12 _1, and the first voltage determination unit. Based on the determination result notified from 16 ₁ , slow-phase operation control and phase-advance operation control of the first inverter power supply 21 ₁ are performed. The first inverter power supply controller 13 ₁ generates the control count P and the state flag C ₁ when performing the slow phase operation control and the phase advance operation control of the first inverter power source 21 ₁ , and the generated control count stored respectively P and the status flag C ₁ to the first control count memory 14 ₁ and the first status flag memory 15 _1.

First voltage determination unit 16 _1, the first according to the instructions of the inverter power source control unit 13 _1, a predetermined whether the utility voltage from the voltage variation rate of the inverter control which may deviate from the optimum value (AC100V) To determine whether or not the voltage of the first inverter power supply 21 ₁ is within an appropriate range, and notifies the _first inverter power supply control unit 13 ₁ of the determination result.

The second to Nth inverter power supply control units 13 _{2 to} 13 _N are configured in the same manner as the first inverter power supply control unit 13 ₁ .

The first inverter power supply 21 _1, as shown in FIG. 3, ₁ and the first rectifier 51, a first storage battery 52 ₁ connected to a first rectifier 51 _{1, 1} and the first rectifier 51 And a first inverter 53 ₁ connected to _one storage battery 52 ₁ . The same applies to the _{second to} Nth inverter power supplies 21 _{2 to} 21 _N.
Here, the first to Nth inverter power supplies 21 _{1 to} 21 _N are subjected to phase advance operation control to cancel the advance power, so that the substation reactive power can be reduced to 0 Var and the voltage can be appropriately reduced. In addition, by controlling the first to Nth inverter power supplies 21 _{1 to} 21 _N in the slow phase operation and canceling the delayed power, the substation reactive power can be set to 0 Var and the voltage can be appropriately increased.
Since the reactive power supply by the inverter power supply is not a substantial power supply, when the line loss reduction due to the power factor improvement is larger than the reactive power supply loss, the first to Nth storage batteries 52 ₁ using midnight power are used. By storing DC power in ˜52 _N , an economic effect can be expected by supplying a DC power supply of daytime power factor with cheap midnight power. That is, since the inverter power supply is a DC power supply, the DC conversion loss can be offset, so that the midnight power can be economically operated as a reactive power adjustment power source during the day only by the charge / discharge loss of the storage battery.
The first to Nth storage batteries 52 _{1 to} 52 _N can use storage batteries having a relatively small capacity. As the first to Nth storage batteries 52 _{1 to} 52 _N , for example, high-efficiency sodium ion batteries can be used.

Next, with respect to the operations of the _first to _Nth reactive power adjustment devices 10 ₁ to 10 _N according to the present embodiment, the case where all of the _{first to Nth} inverter power supplies 21 _{1 to} 21 _N are not in control is illustrated as an example. This will be described with reference to the flowcharts shown in FIGS.

When the first to _Nth control code determination units 12 _{1 to} 12 _N of the _first to _Nth reactive power adjustment devices 10 ₁ to 10 _N start control, a rest time (1 minute) has elapsed. Later (step S11), whether another inverter power supply is under control based on the control state code included in the control code input from the _first to _Nth current increase / decrease determination units 11 _{1 to} 11 _N It is checked whether or not (step S12).

  As a result, when the control status code indicates that another inverter power supply is under control, it takes priority over the other inverter power supply under control based on the priority address code included in the control code. It is checked whether or not the degree is high (step S13). When the priority is low, the operation from step S11 is repeated.

If no other inverter power source is under control in step S12 or if the priority is higher than the other inverter power sources being controlled in step S13, the first to Nth control code determination units 12 _{1 to} 12 _N Notifies the _{first to Nth} inverter power supply control units 13 _{1 to} 13 _N to that effect.
In the case of this example, all of the _{first to} Nth inverter power supplies 21 _{1 to} 21 _N are not under control, and therefore the first invalidity is used to control the first inverter power supply 21 ₁ having the highest priority. the first inverter power source control unit 13 ₁ of the power conditioner 10 ₁ instructs to perform voltage proper range determination process to the first voltage determination unit 16 _1.
Incidentally, for example, when the second inverter power supply 10 ₂ was in control, first inverter power source control unit 13 ₁ priority than the second inverter power supply 10 ₂ is high, the first voltage determination unit 16 instructs to perform the voltage proper range determination processing _1, to deliver the control status code to stop the second operation control of the inverter power supply 10 ₂ is being controlled, the first inverter power supply 10 ₁ Control.

First voltage determination unit 16 ₁ of the first reactive power adjuster 10 _1, according to the first indication of the inverter power source control unit 13 _1, possibly outside the proper value than the voltage variation rate of a predetermined inverter control by determining on the basis of whether or not the commercial power voltage, it determines the voltage of the first inverter power supply 21 ₁ is whether proper range (step S14).
As a result, when the voltage of the first inverter power supply 21 ₁ is not in the proper range, the operation from step S11 is repeated, and in step S14, it is again determined whether or not the voltage of the first inverter power supply 21 ₁ is in the proper range. Determined.
In this way, when it is confirmed that the voltage of the first inverter power supply 21 ₁ is in the proper range and there is no problem with the invalid control, the first voltage determination unit 16 ₁ notifies that to the first inverter power supply control unit 13 _1. Notify

After the first inverter power source control unit 13 _1, which receives this notification from the first voltage determination unit 16 _1, is stored as the control count P = 0 in the first control count memory 14 ₁ (step S15), and It instructs the first control code judging unit 12 ₁ to perform phase advancing-slow operation determination process based on the state flag C _1.

In accordance with this instruction from the _first inverter power supply control unit 13 ₁ , the first control code determination unit 12 ₁ reversely selects the operation control mode of the _first inverter power supply 21 ₁ in order to avoid overcontrol (step) S16).
That is, the first control code judging unit 12 _1, the case reads the status flag C ₁ stored in the first status flag memory 15 _1, the read status flag C ₁ is "1" (i.e., When the first inverter power supply 21 _{1, which} is the inverter power supply to be controlled, is performing the slow phase operation control), the first inverter power supply control unit 13 ₁ is instructed to perform the phase advance operation control ( Step S17). On the other hand, when the read state flag C ₁ is not “1” (when the first inverter power supply 21 ₁ is performing the phase advance operation control), the first control code determination unit 12 ₁ It instructs to perform the slow operation control to the inverter power source control section 13 ₁ (step S18). Note that the first control code determination unit 12 ₁ uses the first inverter power supply when the first inverter power supply 21 ₁ is performing high-efficiency operation or when the first inverter power supply 21 ₁ is not under control. It instructs to perform the slow operation control to the control unit 13 _1.
In the case of this example, since the first inverter power supply 21 ₁ is not under control, the first control code determination unit 12 ₁ performs the slow phase operation control on the first inverter power supply control unit 13 ₁ . To instruct.

In addition, the first control code determination unit 12 ₁ indicates that control is being performed in order to indicate that the slow phase operation control of the control amount of 10 kVar is being performed on the first inverter power supply 21 ₁ . And the control code containing the priority address code which shows the priority address of the 1st inverter power supply 21 ₁ is produced | generated, and the produced | generated control code is output to the _1st inverter power supply control part 13 ₁ .

The first inverter power supply control unit 13 ₁ sends a pulse advance corresponding to the control status code to the first inverter power supply 21 ₁ in accordance with an instruction and a control code from the _first control code determination unit 12 _1. After performing the control and the pulse phase advance control corresponding to the priority address code, the slow phase operation control is performed as follows.

The first inverter power supply control unit 13 ₁ outputs a control signal for performing a slow phase operation control with a control amount of 10 kVar to the first inverter power supply 21 ₁ (step S21 in FIG. 5), and the first voltage determination unit 16 ₁ is instructed to perform appropriate voltage range determination processing.
The first voltage determination unit 16 ₁ determines whether or not the voltage of the first inverter power supply 21 ₁ is within an appropriate range as described in step S14 according to the instruction of the first inverter power supply control unit 13 _1. (Step S22).

The first inverter power source control unit 13 _1, the first voltage determination unit 16 ₁ "first voltage of the inverter power supply 21 ₁ is not proper range" Upon receiving the notification of the fact, to reduce the control amount only 10kVar The original control amount is restored (step S34). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.
The first inverter power source control unit 13 _1, the first voltage determination unit 16 ₁ "first voltage of the inverter power supply 21 ₁ is proper range" Upon receiving the notification of the fact, the first control code judging unit 12 ₁ is instructed to determine again whether or not the other inverter power supply is under control (step S23), and the first control code determination unit 12 ₁ indicates that “the other inverter power supply is under control. When the determination result is received, the control amount is decreased by 10 kVar and returned to the original control amount (step S34). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.

On the other hand, the first from the control code judging unit 12 ₁ of the "other inverter power supply is not in control" when receiving the judgment result of the fact, the first inverter power source control unit 13 _1, the first current decrease determination unit 11 ₁ It is checked whether or not the distribution line current input from the line has decreased by about 0.1 to 0.6 A (step S24).

As a result, when the distribution line current decreases by about 0.1 to 0.6 A, the first inverter power supply controller 13 ₁ is within the control capacity (for example, 100 kVar) of the first inverter power supply 21 _1. or the checked (step S25), and if the first inverter power source 21 within _a control volume, and determines the operation control direction and lagging phase driving directions, slow the status flag C ₁ of the first inverter power supply 21 ₁ The state flag C ₁ = 1 is stored in the state flag memory 15 by determining “1” indicating the phase operation direction (step S26).

Thereafter, the first inverter power source control unit 13 ₁ enters the + 20KVar operation control for reinforcing the further slow operation control (step S21). Thereby, the operation | movement from step S22 is repeated and appropriate reactive power is determined.

On the other hand, if it is not within the control capacity of the first inverter power supply 21 ₁ in step S25 described above, the first inverter power supply control unit 13 ₁ reduces the control amount by 10 kVar and returns it to the original control amount, and the control count After “1” is added to P to set P = 1, the control count P = 1 is stored in the _first control count memory 141 (step S27). Thereafter, the following operations from step S29 are performed.

Also, if the distribution line current in step S24 described above is not decreasing, the first inverter power source control unit 13 _1, after returning the control amount by decreasing the controlled variable only 10KVar (step S28), distribution It is examined whether or not the electric wire current decreases (step S29).
As a result, when the distribution line current has not decreased, it is determined that adjustment is impossible, and the first inverter power supply control unit 13 ₁ causes the first inverter power supply 21 ₁ to perform high-efficiency operation (0 kVar). At the same time, the status flag C ₁ of the first inverter power supply 21 ₁ is fixed to “0” indicating high-efficiency operation control, and the status flag C ₁ = 0 is stored in the status flag memory 15 (step S30). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.

On the other hand, if the distribution line current is reduced in step S29, the first inverter power source control unit 13 _1, first reads the control count P from the control count memory 14 _1, the read control count P is It is checked whether or not “1” or more (step S31).
As a result, if the control count P is “1” or more, the operation from step S11 shown in FIG. 4 is repeated.
In this example, since the control count P is less than be "0""1", the first inverter power source control unit 13 _1, and a P = 1 by adding "1" to the control count P Thereafter, the control count P = 1 is stored in the _first control count memory 141 (step S32). Thereafter, the first inverter power supply controller 13 ₁ performs the phase advance operation control of the first inverter power supply 21 ₁ as follows (step S33).

The first inverter power supply control unit 13 ₁ outputs a control signal for performing phase advance operation control with a control amount of −10 kVar to the first inverter power supply 21 ₁ (step S41 in FIG. 6), and the first voltage determination unit. 16 ₁ is instructed to perform appropriate voltage range determination processing.
The first voltage determination unit 16 ₁ determines whether or not the voltage of the first inverter power supply 21 ₁ is within an appropriate range as described in step S14 according to the instruction of the first inverter power supply control unit 13 _1. (Step S42).

The first inverter power source control unit 13 _1, the first voltage determination unit 16 ₁ "first voltage of the inverter power supply 21 ₁ is not proper range" Upon receiving the notification of the fact, by increasing the controlled variable only 10kVar The original control amount is restored (step S54). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.
The first inverter power source control unit 13 _1, the first voltage determination unit 16 ₁ "first voltage of the inverter power supply 21 ₁ is proper range" Upon receiving the notification of the fact, the first control code judging unit 12 ₁ is instructed again to determine whether or not another inverter power supply is under control (step S43), and the first control code determination unit 12 ₁ indicates that “the other inverter power supply is under control. When the determination result is received, the control amount is increased by 10 kVar and returned to the original control amount (step S54). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.

On the other hand, the first from the control code judging unit 12 ₁ of the "other inverter power supply is not in control" when receiving the judgment result of the fact, the first inverter power source control unit 13 _1, the first current decrease determination unit 11 ₁ It is checked whether or not the distribution line current input from the terminal has decreased by about 0.1 to 0.6 A (step S44).

As a result, when the distribution line current decreases by about 0.1 to 0.6 A, is the first inverter power supply controller 13 ₁ within the control capacity (for example, −100 kVar) of the first inverter power supply 21 ₁ ? whether the checked (step S45), if the first inverter power source 21 within _a control volume, and determines the operation control direction and phase advance operation direction, the status flag C ₁ of the first inverter power supply 21 ₁ The state flag C ₁ = −1 is stored in the state flag memory 15 by determining “−1” indicating the phase advance operation direction (step S46).

Thereafter, the first inverter power source control unit 13 ₁ is further enters the operation control of -20kVar to enhance the phase advance operation control (step S41). Thereby, the operation | movement from step S42 is repeated and appropriate reactive electric energy is determined.

On the other hand, if it is not within the control capacity of the first inverter power supply 21 ₁ in step S45 described above, the first inverter power supply control unit 13 ₁ increases the control amount by 10 kVar and returns it to the original control amount. After “1” is added to P to set P = 1, the control count P = 1 is stored in the _first control count memory 141 (step S47). Thereafter, the following operations from step S49 are performed.

Also, if the distribution line current in step S44 described above is not decreasing, the first inverter power source control unit 13 _1, after returning the control amount by increasing the controlled variable only 10KVar (step S48), distribution It is examined whether or not the electric wire current decreases (step S49).
As a result, when the distribution line current has not decreased, it is determined that adjustment is impossible, and the first inverter power supply control unit 13 ₁ causes the first inverter power supply 21 ₁ to perform high-efficiency operation (0 kVar). At the same time, the state flag C ₁ of the first inverter power supply 21 ₁ is fixed to “0” indicating high-efficiency operation control, and the state flag C ₁ = 0 is stored in the state flag memory 15 (step S50). Thereafter, the operation from step S11 shown in FIG. 4 is repeated.

On the other hand, if the distribution line current is reduced in step S49, the first inverter power source control unit 13 _1, first reads the control count P from the control count memory 14 _1, the read control count P is It is checked whether or not “1” or more (step S51).
As a result, if the control count P is "1" or more, the first inverter power source control unit 13 _1, the flow returns to step S11 shown in FIG. In this example, since the control count P is "1", the first inverter power source control unit 13 ₁ enters the 1 minute rest time.
The control If the count P is less than "1", after the first inverter power source control unit 13 _1, which "1" is first stored in the control count memory 14 ₁ in addition to the control count P (step (S52), the process shifts to the slow phase operation control (step S53).

In the above, the case where the reactive power is adjusted by performing the slow phase operation control or the phase advance operation control of the _{first to Nth} inverter power supplies 21 _{1 to} 21 _N distributedly arranged in one distribution line 2 has been described. However, by performing the slow phase operation control or the phase advance operation control for each of the distribution lines in the same manner for the plurality of inverter power supplies that are respectively distributed on the plurality of distribution lines connected to the bus 1. The reactive power can be adjusted effectively.

  As described above, the current monitoring reactive power adjustment device of the present invention can be used, for example, to suppress a voltage rise at the end of a distribution line due to a phase advance voltage generated at midnight.

It is a block diagram which shows the structure of the reactive power adjustment apparatus 10 by one Example of this invention. It is a figure for demonstrating a control code. It is a diagram for explaining a first inverter power source 21 ₁ having the configuration shown in FIG. 4 is a flowchart for explaining the operation of the reactive power adjustment apparatus 10 shown in FIG. 1. 4 is a flowchart for explaining the operation of the reactive power adjustment apparatus 10 shown in FIG. 1. 4 is a flowchart for explaining the operation of the reactive power adjustment apparatus 10 shown in FIG. 1. It is a figure for demonstrating the relationship between a reactive power and a distribution line electric current.

Explanation of symbols

1 bus 2 distribution line 3 transformer 4 ₁ to 4 _N current increase or decrease of the first through the N-th current transformers 10 ₁ to 10 _N reactive power adjuster of the first to N 11 ₁ to 11 _N first to N Determination units 12 _{1 to} 12 _{N 1st} to _Nth control code determination units 13 _{1 to} 13 _N 1st to Nth inverter power supply control units 14 _{1 to} 14 _N 1st to Nth control count memories 15 ₁ to 15 _N 1st to Nth state flag memories 16 _{1 to} 16 _N 1st to Nth voltage determination sections 21 _{1 to} 21 _N 1st to Nth inverter power supplies 51 _{1 to} 51 _N 1st to Nth rectifiers 52 _{1 to} 52 _N first to Nth storage batteries 53 _{1 to} 53 _N first to Nth inverters P control count C _k (k = 1 to N) state flags S11 to S18, S21 to S34, S41 to S54 Steps

Claims (8)

Connected to a plurality of inverter power supplies (21 _{1 to} 21 _N ) distributed on the distribution line (2) branched from the bus (1), respectively, and in the vicinity of the plurality of inverter power supplies of the distribution line, respectively. Based on the distribution line current input from a plurality of distributed current transformers (4 ₁ to 4 _N ), the inverter power source arranged on the terminal side of the distribution line is given priority to control the slow phase operation or advance. A current monitoring reactive power adjusting device (10 ₁ to 10 _N ) for adjusting reactive power by performing phase operation control,
Control code determining means (12 _{1 to} 12 _N ) for checking whether or not another inverter power supply is under control and checking whether or not the priority of the other inverter power supply under control is high;
When receiving a determination result indicating that “the other inverter power supply having a higher priority is not being controlled” from the control code determination means, the current monitoring reactive power adjustment device is disposed in the vicinity of the connected inverter power supply. Inverter power supply control means (13 _{1 to} 13 _N ) for performing slow phase operation control or phase advance operation control of the inverter power supply so that the distribution line current input from the current transformer is reduced;
A current monitoring reactive power adjusting device comprising:   The plurality of inverter power supplies are prioritized by priority addresses whose numerical values increase in the order of the inverter power supply arranged on the terminal end side of the distribution line to the inverter power supply arranged on the tip end side of the distribution line. The current monitoring reactive power adjustment device according to claim 1, wherein   The inverter power supply control means includes a control code including a control status code indicating whether or not the inverter power supply controlled by the inverter power supply control means is under control and a priority address code indicating the priority address of the inverter power supply. 3. The current monitoring according to claim 1, wherein a pulse phase advance control corresponding to the control status code and a pulse phase advance control corresponding to the priority address code are respectively performed on the inverter power supply. Type reactive power adjustment device. Whether or not the voltage of the inverter power supply controlled by the inverter power supply control means is within an appropriate range by determining whether or not there is a possibility of deviating from an appropriate value from a predetermined voltage fluctuation rate of the inverter control based on the commercial voltage. or to determine the, the determination result and further comprising a voltage determining means for notifying the inverter power source control means (16 ₁ ~ 16 _N), current monitoring type according to any of claims 1 to 3 Reactive power adjustment device. Further comprising a status flag memory (15 ₁ ~15 _N) for storing said plurality of inverter power supply status flag (C _k),
Whether or not the distribution line current has decreased by a predetermined range when the inverter power supply control means performs the slow phase operation control or the phase advance operation control on the inverter power supply controlled by the inverter power supply control means. If the distribution line current decreases by a predetermined range, the status flag of the inverter power supply is determined in the slow phase operation direction or the phase advance operation direction, and the determined status flag is stored in the status flag memory. Remember
The current monitoring reactive power adjustment device according to any one of claims 1 to 4, wherein   When the inverter power supply control means performs slow phase operation control or phase advance operation control on the inverter power supply controlled by the inverter power supply control means, the direction opposite to the previous operation control direction based on the state flag 6. The current monitoring reactive power adjustment device according to claim 1, wherein slow phase operation control or phase advance operation control is performed. A control count memory (14 _{1 to} 14 _N ) for storing a control count (P) input from the inverter power supply control means;
If the inverter power supply control means cannot adjust the reactive power even if one of the slow phase operation control and the advanced phase operation control is performed on the inverter power supply controlled by the inverter power supply control means, the control count memory The stored control count is read, and when the read control count is not equal to or greater than “1”, “1” is added to the control count and stored in the control count memory, and then the delayed operation control and the advanced operation are performed. The other control is performed, and when the read control count is “1” or more, the control count is set to “0” after a certain rest time has elapsed and is opposite to the previous operation control direction based on the control code. Execute slow phase operation control or phase advance operation control
The current monitoring reactive power adjustment device according to any one of claims 1 to 6, wherein The inverter power supply is
A rectifier (51 _{1 to} 51 _N ), a storage battery (52 _{1 to} 52 _N ) connected to the rectifier, and an inverter (53 _{1 to} 53 _N ) connected to the rectifier and the storage battery,
Storing power in the storage battery when there is a surplus of late-night electricity, and supplying reactive power from the storage battery when there is insufficient daytime electricity,
The current monitoring type reactive power adjustment device according to claim 1, wherein

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