JP3030813B2 - Standalone operation detection device for private power generation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an isolated operation detection device for a private power generation facility installed in a power consumer.

[0002]

2. Description of the Related Art In recent years, consumers who consume a large amount of electric power have installed private power generators to save electric power in the office and to supply electric power to the office when an emergency power failure or the like occurs.
2. Description of the Related Art Private power generation facilities for supplying inexpensive power generated by a private power generator to a private load in a facility while receiving a constant supply of power from a power company are being actively installed. The private power generation equipment and the power supply system of the electric power company are provided with necessary measures to maintain safety in accordance with the “Guidelines for System Interconnection Technology”, such as failures in private power generation equipment and power supply side failures. In the event of a failure, various protection devices prevent the loss of equipment on the load side, and are working to quickly recover from a failure.

However, in recent years, laws and regulations have been amended on the power supply side to actively purchase surplus power from distributed power sources such as new energy, and even private power generation facilities have been changed to the power supply side under certain conditions. As a result, surplus electric power can be sold according to the interconnection, and it is no longer necessary to provide a reverse power flow prevention device. However, in a facility in which reverse power flow is allowed so that the surplus power of the private generator can be supplied to the power supply side, whether the power supply side is in an unhealthy state,
That is, whether the circuit breaker on the power station side of the power company is open,
Alternatively, it is not possible to detect whether the distribution line is disconnected or not on the private power generation equipment side, and the interconnecting circuit breaker on the private power generation equipment side in a state where each breaker on the power supply side is opened due to a failure of the distribution line or the like. Is closed and the private power plant operates alone,
There is a problem that the voltage of the private generator is applied to the faulty distribution line on the power supply side, and maintenance and inspection of the distribution line, restoration work, and the like become dangerous.

[0004] In order to prevent the occurrence of various accidents by accurately opening the circuit breaker of the private power generation facility when the power supply side is in an unhealthy state, the private power generation facility connected to the power supply side is required. There is a demand for a device that can easily detect that the power supply side is unhealthy and the private power generation facility is operating alone.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a problem in that a private power generator is operated in an unhealthy state from a private power generator connected to a power supply side. Operation detection device for private power generation equipment, which can easily detect that the power supply side is in an unhealthy state and accurately open the circuit breaker of the private power generation equipment to prevent the occurrence of various accidents The purpose is to provide.

[0006]

According to a first aspect of the present invention, there is provided an apparatus for detecting the isolated operation of a private power generator, which supplies electric power.
If power is supplied from the grid power company via distribution lines,
Private generators, which are mainly supplied with power from private generators
Private power generation equipment with load and distribution on the grid power side
On the branch line between the line and the private generator
Current detector and the current detector in the branch line
This is a resistor connected to the home generator via a switch
Detection impedance load and current flowing through current detector
Phase detector that detects the phase of the
The phase of the current detected by the detector and the phase at switch-on
The difference from the phase of the current detected by the transmitter is larger than the specified value
Doo-out the private power generation equipment is grid power company side and the interconnection Ken
An islanding operation determination unit that determines that the operation is normal.
You.

According to a second aspect of the present invention, there is provided an islanding operation detection apparatus for a private power generation facility, in which power is supplied from a system power company supplying power via a distribution line, and power is mainly supplied from a private power generator. A private power generation facility having a private load, comprising: a first power generation unit provided in series with a branch line provided between a distribution line on the system power side and a private power generator;
And a second current detector, and first and second current detectors in the branch line.
Resistor which is connected via the switch to the connection point of the current detector
The impedance load for detection, which is a resistance, and the first on the distribution line side.
Phase detecting the phase of the current flowing through the current detector of
Detector and a second current detector on the private generator side
A second phase detector for detecting the phase of the current;
Phase of the current detected by the first or second phase detector at the time of
Of the current detected by the first phase detector when the switch is turned on.
When the difference from the phase is larger than a predetermined value, the private power generation equipment is connected to the grid power company side, and it is determined that the state is sound and normal, and the first or second phase detector at the time of switch-off is detected.
Current phase and the second phase detector at switch on
If the difference from the detected current phase is larger than a predetermined value, it is determined that the private power generation equipment is operating in an unhealthy state while the private power generation equipment is connected to the grid power company side in an unhealthy state. Section.

[0008] The private power generation equipment according to claim 3 of the present invention.
Is the islanding detection device connected to the grid
Power is supplied via distribution lines and is
For private use with a private load that is primarily powered
Power generation equipment, including distribution lines on the grid power side and private generators
Current detector provided on the branch line provided between
From the current detector on the branch line to the private generator side.
Detector is a resistor connected through a switch
Load and the peak value of the current flowing through the current detector
Current peak value detector and the current peak
Current value detected by the current value detector and when the switch is turned on.
Difference from the current peak value detected by the current peak value detector
Is larger than the specified value, the private power generation
Judgment of islanding operation linked to the
And a fixed part.

[0009] The private power generation equipment according to claim 4 of the present invention.
Is the islanding detection device connected to the grid
Power is supplied via distribution lines and is
For private use with a private load that is primarily powered
Power generation equipment, including distribution lines on the grid power side and private generators
And a first line provided in series with a branch line provided between
And a second current detector, and first and second current detectors in the branch line.
Connected via a switch to the current detector connection point
The impedance load for detection, which is a resistance, and the first on the distribution line side.
Detecting the peak value of the current flowing through the current detector of
A current peak value detector and a second current detector on the private generator side.
The second current peak for detecting the peak value of the current flowing through the output device
Value detector and the first or second current pin when the switch is off.
Peak value of current detected by peak value detector and switch on
Of the current detected by the first current peak value detector at the time
If the difference from the value is larger than the predetermined value,
The system is connected to the grid power side, and it is determined that the
The first or second current peak value detector at the time of switch-off is detected.
The peak value of the output current and the second current
The difference between the peak value of the current detected by the
If the value is larger than the value, the private power generation equipment
The private power generation facility operates in an unhealthy state during interconnection.
And an islanding operation judging unit for judging the case.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a single-line diagram showing the configuration of an isolated operation detection device for a private power generation facility according to Embodiment 1 of the present invention, and FIG. FIG. 3 is a schematic waveform diagram of a current flowing through the detection impedance load, and FIG. 3 is an actual waveform diagram of a current flowing from the branch line of the isolated operation detection device to the detection impedance load. In the figure, 1 is a grid power company that supplies power, 2 is a private power generation facility to which power is supplied from the grid power company 1 via a distribution line 3, and 4 is provided between the grid power company 1 and the distribution line 3. It is a system side interconnection breaker . A plurality of general loads 5 are connected to the distribution line 3.
These general loads 5 are separated from the distribution line 3 to prevent danger when a circuit breaker, disconnector, or the like is connected inside and a ground fault or the like occurs. 6 is provided private power plant 2, the branch line is branched from the branch line P of the distribution line 3,
7 is a private circuit breaker connected to the branch point P side of the branch line 6, 8 is a private generator connected to the terminal side of the branch line 6,
Reference numeral 9 denotes a private load connected to the private generator 8 via the branch line 6.

[0011] 10 and 11 are provided in series <br/> first and second current detectors (CT1, CT2) to the branch line 6.
12 a connection point of the first and second current detectors 10, 11 a
The connected switch, 13 is connected via a switch 12 to the connection point a resistance of the first and second current detectors 10 and 11, the detection impedance load such as a capacitor,
Reference numeral 14 denotes a first phase detector for detecting the phase of the current flowing through the first current detector 10 on the distribution line 3 side (hereinafter, referred to as “system side”) when the switch 12 is on and off. A second phase detector for detecting the phase of a current flowing through the second current detector 11 on the private generator 8 side (hereinafter, referred to as “generator side”) when the power is on and off, and 16 is a first current on the system side The first current peak value detector 17 detects the peak value of the current flowing through the detector 10, and 17 is the second current detector 1 on the generator side .
A second current peak value detector 18 for detecting the peak value of the current flowing in 1 is connected to the first and second phase detectors 14 and 15 and the first and second current peak value detectors 16 and 17. And an islanding operation determination unit that detects the islanding operation of the private power generation facility 2 from these detected values.

First, an outline of the principle by which the isolated operation of the private power generation facility 2 can be detected by the private operation detection apparatus for private power generation equipment according to the first embodiment of the present invention will be described. For example, the electric power required by the private load 9 in the private power generation facility 2 is supplied while driving the private generator 8. When the power of the private load 9 is required to be higher than the output of the private generator 8, the insufficient power is supplied from the grid power company 1 to the private load 9 via the private interconnection breaker 7. When the load capacity of the private load 9 decreases and surplus power is generated in the output of the private generator 8, the surplus power is automatically transmitted from the private interconnection circuit breaker 7 to the system power company 1 which is the power supply side. The surplus power is sold to the grid power company 1 with a reverse tide. By the way, the private power generation equipment 2 is the grid power company 1
As shown in FIG. 2, in the case where the power generation system is connected to the system and is in a normal state, and in the case where the private power generation facility 2 is operating alone in an unhealthy state during the connection with the system power company 1, as shown in FIG. When the detection impedance load 13 is applied to the branch line 6 provided between the distribution line 3 on the first side and the private generator 8,
By the phase angle of the peak value and the current waveform of a current flowing in the line side of the branch line 6 and the generator side are different, respectively, determine whether the normal case based on that, when the sole operation of the unhealthy state It is something to do. Here, the case where the private power generation facility 2 is operating alone in an unhealthy state during interconnection with the system power company 1 side means that a failure occurs on the system power company 1 side and the system side It means that the circuit is open or the distribution line 3 is disconnected.

When the private power generation equipment is connected to the grid power company side and is healthy and normal, the current flowing through the branch line 6 on the grid side and the generator side without inputting the detection impedance 13 is first and second. When the currents are detected by the two current detectors 10 and 11, the current waveforms of the two are the same as shown on the left side of FIG. Further, in a normal case, when the switch 12 is turned on and the detection impedance load 13 is turned on, the current flowing through the system side of the branch line 6 and the generator side is changed to the first state.
And upon detecting by the second current detector 10 and 11, current is the current waveform as shown on the right side of FIG. 2 (a), the second current detector 11 on the generator side of (CT2) is detected Does not change, but the peak value and phase of the current detected by the first current detector 10 (CT1) on the system side change (that is, the peak value of the current decreases and the phase of the current changes). It can be seen that the current advances by θ when the zero-cross point of both currents is used as a reference.

Next, in a case where the private power generation equipment is in an unhealthy state while being interconnected with the grid power company side and the private power generation equipment is operating alone, the branch line is supplied without inputting the detection impedance load 13. When the first and second current detectors 10 and 11 detect currents flowing on the system side and the generator side of No. 6, both current waveforms are the same as shown on the left side of FIG. is there. Further, in the case of the isolated operation in an unhealthy state, when the switch 12 is turned on and the detection impedance load 13 is turned on, the current flowing through the system side and the generator side of the branch line 6 is changed to the first and second currents. When the current is detected by the current detectors 10 and 11, the current waveform does not change in phase with the peak value of the current detected by the current detector 10 (CT1) on the system side, as shown on the right side of FIG. However, the peak value and phase of the current detected by the current detector 11 (CT2) on the generator side change (that is, as the peak value of the current increases, the phase of the current is determined based on the zero crossing point of both currents). And θ
Just go forward). Therefore, the first and second
By checking the change in the peak value of the current detected by the current detectors 10 and 11 or by checking the phase of the current, the private power generation equipment is interconnected with the grid power company side and is in a normal state. It is possible to determine that the private power generation facility is operating alone in an unhealthy state during interconnection with the side.

Next, the operation of the isolated operation detection device for the private power generation equipment according to the first embodiment of the present invention will be described. Ma
The current flowing through the branch line 6 when the switch 12 is off.
Detection is performed by the first and second current detectors 10 and 11. No.
In the first and second phase detectors 14, 15, the first and second phase detectors
Detecting the phase of the current detected by the current detectors 10 and 11
Output to the isolated operation determination unit 17. In addition, the first and second
The first and second currents are detected by the current peak value detectors 16 and 17.
Detecting the peak value of the current detected by the detectors 10 and 11
Output to the isolated operation determination unit 17. Next, when the switch 12 is turned on (the on-time is about 1/50 second) and the detection impedance load 13 is turned on, the current flowing through the branch line 6 is passed through the first and second current detectors 10 and 11. To detect. The first and second phase detectors 14 and 15 detect the phases of the currents detected by the first and second current detectors 10 and 11 and output the detected phases to the isolated operation determination unit 17. Further, the first and second <br/> current peak value detector in the 16 and 17 first and second current detectors 10, 11 detects the peak value of the current detected isolated operation determination unit 17 Output.

The isolated operation determining section 17 determines the phase of the current detected by the first or second phase detector 14 or 15 when the switch is off and the phase of the current detected by the first phase detector 14 when the switch is on. When the phase of the current detected by the first phase detector 14 at the time of switch-on is advanced from the phase of the current detected by the second phase detector 15 at the time of switch-off, the phase difference θ Is larger than the predetermined phase difference θref, it is possible to determine that the private power generation facility 2 is connected to the grid power company 1 side and is healthy and normal. Further, the first or second phase detector 14 when the switch is off,
The phase of the current detected by the first phase detector 14 is compared with the phase of the current detected by the second phase detector 14 when the switch is on, and the phase of the current detected by the first phase detector 14 when the switch is off is switched on. In the state where the phase of the current detected by the second phase detector 15 is advanced, if the phase difference θ between the two is larger than the predetermined phase difference θref, the private power generation equipment 2 is disabled while being linked with the grid power company 1 side. It can be determined that the private power generation facility 2 is operating alone in a healthy state.

Further, in the islanding operation determining section 17, the first or second current peak value detectors 16, 1 at the time of switch-off are provided.
7 is compared with the peak value of the current detected by the first current peak value detector 16 when the switch is turned on, and the peak value of the current detected by the second current peak value detector 17 when the switch is turned off. First value at switch on for value
In a state where the peak value of the current detected by the current peak value detector 16 is decreasing, the difference A between the two peak values is a predetermined value Aref.
If it is larger, the private power generation facility 2 is connected to the grid power company 1 side, and it can be determined that the case is sound and normal. Further, the peak value of the current detected by the first or second current peak value detector 16 or 17 when the switch is off is compared with the peak value of the current detected by the second current peak value detector 17 when the switch is on. In a state where the peak value of the current detected by the second current peak value detector 16 at the time of switch-on is increased with respect to the peak value of the current detected by the first current peak value detector 16 at the time of switch-off, Difference A between both peak values
Is larger than the predetermined value Aref, it can be determined that the private power generating facility 2 is operating alone while the private power generating facility 2 is in an unhealthy state during system interconnection.

The reason why the current at the time of switch-off is used to judge the normal case and the unsound operation in the unsound state based on the current phase and the current peak value is as follows. This is because the current at the time of switch-on is determined based on the zero cross point of the current at the time of switch-off. When the determination based on the current phase difference and the determination based on the peak value of the current are the same, the isolated operation determination unit 17 of the first embodiment
The determination is made separately for a case where the power generation equipment is connected to the power generation system and is in a normal state, and a case where the power generation equipment for private use is in an unhealthy state while the power generation equipment for private use is connected to the grid power company 1 side. This is because the determination can be made more accurately from two viewpoints. Therefore, when it is determined that the private power generation facility 2 is operating alone in an unhealthy state while the private power generation facility 2 is connected to the grid power company 1 side, the private power generation facility 2 is immediately switched to the grid power company. By separating the power generation equipment 1 from the side, it is possible to prevent various types of accidents, such as damage to the equipment on the private power generation facility 2 side and accidents during maintenance and inspection of the distribution line 3 on the grid power company 1 side.

As a result, the private generator 8 can supply electric power to the private load 9 in the facility while operating continuously, and the system-side interconnecting circuit breaker 4 and other circuit breakers are opened due to a failure, and the private generator 9 is in a no-load state. Without power being transmitted to the power line 3 by the private generator 8 or the like, the failure and recovery work can be performed safely. Also immediately it is closed the system side interconnection circuit breaker 4 of the system power company 1 side, shielding private communication system after a failure recovery distribution line 3
If the breaker 7 is open, the equipment on the side of the private power generation facility 2 is not damaged, and the voltage, frequency, phase, etc. of the private generator 8 are accurately synchronized with the system power company 1 side by a synchronization tester or the like. After that, the private power circuit breaker 7 is closed, and the private power generating equipment 2 is connected to the grid power company 1 while being connected to the grid, to return to the normal state.

In practice, the switch 12 is turned on for a certain period based on the zero-cross point of the current in the branch line 6 when the switch 12 is off, and this is repeated at least once periodically, irregularly or continuously. Like that. For example,
The switch 12 is continuously turned on and off at intervals of 0.1 to 0.2 seconds in 1/50 second to determine the average and the average of the phase and peak value of the current obtained, so that accurate determination can be made. ing. In the above-described embodiment, the islanding operation determination unit 17 connects the private power generation facility 2 to the grid power company 1 side when the determination based on the current phase difference and the determination based on the peak value of the current are the same. The normal power generation facility 2 and the private power generation facility 2 are operated independently when the private power generation facility 2 is connected to the grid power company 1 in an unhealthy state. The private power generation facility 2 is connected to the grid power company 1 side only when the private power generation facility 2 is connected to the grid power company 1 side, and the private power generation facility 2 is connected to the grid power company 1 side only by the determination based on the phase difference or the peak current value. Of course, it is possible to determine whether the private power generation facility 2 is operating alone in an unhealthy state.

[0021]

As described above, according to the first aspect of the present invention, when the private power generation equipment is connected to the power supply side.
Between the distribution line of the grid power company and the private generator.
Current detection provided on the branch line
The generator side of the generator and the negative impedance for resistance detection
When the switch provided between the load and the load is turned on or off
The phase detector detects when the islanding operation
The phase of the output current and the phase detector at switch-on are detected
If the difference from the phase of the current
Private power generation facilities are connected to the grid
Because it can be judged that it is always the case, private power generation equipment
Is connected to the grid power company
It is determined that private power generation equipment is operating alone in an unhealthy state.
And immediately separate private power generation equipment from the grid power company
Damage to the equipment on the private power generation equipment side, or
Various types of accidents such as accidents during maintenance and inspection of distribution lines
This has the effect that generation can be prevented.

According to the second aspect of the present invention, when the private power generation equipment is connected to the power supply side, it is provided between the distribution line on the system power company side and the private power generator. When a switch provided between a connection point of the first and second current detectors provided in series with the branch line and an impedance load for detecting a resistance is turned on and off, the isolated operation determination unit is turned off. The first or second phase detector
Phase of the output current and first phase detector at switch-on
First addition but the difference between the phase of the detected current during a predetermined private power generation equipment is system power company and the communication system determines that the case of the healthy normal is greater than the phase difference, also switched off
Is the phase of the current detected by the second phase detector and
When the difference between the phase of the current detected by the second phase detector and the phase difference is larger than the predetermined phase difference, the private power generation facility is in an unhealthy state during interconnection with the grid power company and the private power generator alone If it is determined that the private power generation equipment is operating alone in an unhealthy state, the private power generation equipment is immediately separated from the grid power company side, and the This has the effect of preventing the occurrence of various accidents such as damage to equipment and accidents during maintenance and inspection of distribution lines on the grid power company side.

Further, according to claim 3 of the present invention,
System is connected to the power supply side
Installed between the distribution line of the power company and the private generator
From the current detector attached to
Between the home generator and the impedance load for detecting the resistance
When the switch provided in the
The current judgment is detected by the current peak value detector when the switch is turned off.
The peak value of the detected current and the peak current value at switch-on
The difference between the peak value of the current detected by the transmitter and the
At times, private power generation equipment is connected to the grid power company.
Can be determined to be healthy and normal.
Power generation facilities are connected to the grid power company
In other cases, the private power generation equipment operates alone in an unhealthy condition.
Power generation facilities and immediately
From the side, damage to the equipment on the private power generation facility side, or
Or other accidents during maintenance and inspection of distribution lines
This has the effect of preventing the occurrence of any kind of accident.

According to a fourth aspect of the present invention, a private use
If the power plant is powered side and interconnection, system electrodeposition
The part installed between the power company's distribution line and the private generator
The connection of the first and second current detectors provided in series with the branch line
Between the connection point and the impedance load for detecting the resistance.
When the switch is turned on or off, the islanding
First or second current peak value detector when switch off
The peak value of the detected current and the first
The difference from the peak value of the current detected by the
If the value is larger than the specified value, the private power generation equipment is
Is linked to the
The first or second current peak value detector at the time of
Current peak value and second current peak at switch-on
The difference between the peak value of the current detected by the value detector and the
Private power generation facilities are connected to the grid power company
The private power generation facility is operating alone in an unhealthy state
The power generation facilities for private use are not
Immediately for private use if it is determined that the vehicle is operating in a healthy state
Separate the power generation facilities from the grid power company side, and
Equipment on the equipment side, or the distribution line on the grid power company side
It is possible to prevent the occurrence of various accidents such as accidents during maintenance and inspection.
This has the effect.

[Brief description of the drawings]

FIG. 1 is a single-line diagram showing a configuration of an isolated operation detection device for a private power generation facility according to Embodiment 1 of the present invention.

FIG. 2 is a schematic waveform diagram of a current flowing from a branch line of the isolated operation detection device to a detection impedance load.

FIG. 3 is an actual waveform diagram of a current flowing from a branch line of the isolated operation detection device to a detection impedance load.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grid power company 2 Private power generation equipment 3 Distribution line 6 Branch line 8 Private generator 9 Private load 10 First current detector (CT1) 11 Second current detector (CT2) 12 Switch 13 Impedance load for detection 14 First phase Detector 15 Second phase detector 16 First current peak detector 17 Second current peak detector 18 Islanding operation determination unit

Claims (4)

(57) [Claims] 1. Distribution from the grid power company that supplies power
Power is supplied through the power line, and the
Power generator with a private load that is supplied with power
Installed between the distribution line on the grid power side and the private generator.
The current detector provided in the branch line and the current detector in the branch line
Impedance, which is the resistance connected through the switch
Phase detector that detects the phase of the load and the current flowing through the current detector
And the phase and current of the current detected by the phase detector when the switch is off.
Difference from the phase of the current detected by the phase detector when the switch is on
Is larger than the specified value, the private power generation
Single operation that is linked to the company and determines that it is sound and normal
A self-power generation facility,
Islanding detection device. 2. A private power generation facility having a private load to which power is supplied from a grid power company that supplies power via a distribution line and that is mainly supplied with power from a private generator, It is provided between the distribution line and private power generator
First and second current detectors provided in series on a branch line, and a detection impedance load as a resistor connected via a switch to a connection point of the first and second current detectors on the branch line And the phase of the current flowing through the first current detector on the distribution line side
Phase of the first phase detector and the phase of the current flowing through the second current detector on the private generator side
And the first or second phase detector when the switch is turned off is detected.
Current phase and first phase detector at switch on detect
When the difference from the phase of the detected current is larger than a predetermined value, it is determined that the private power generation equipment is connected to the grid power company side and is in a healthy state, and the first or second phase detection at the time of switch-off is performed.
The phase of the current detected by the transmitter and the second position at switch-on
When the difference between the phase of the current detected by the phase detector and the current value is larger than a predetermined value, it is determined that the private power generation facility is operating in an unhealthy state while the private power generation facility is connected to the grid power company side in an unhealthy state. An isolated operation detection device for a private power generation facility, comprising: 3. Distribution from the grid power company that supplies power
Power is supplied through the power line, and the
Power generator with a private load that is supplied with power
Installed between the distribution line on the grid power side and the private generator.
The current detector provided in the branch line and the current detector in the branch line
Impedance, which is the resistance connected through the switch
The load and the current peak that detects the peak value of the current flowing through the current detector
Value detector and the current detected by the current peak value detector when the switch is off.
Peak value and current peak value detector at switch on detected
If the difference from the current peak value is larger than the specified value
Private power generation equipment is connected to the grid power side to
And an islanding operation judging unit for judging the case.
Operation detection device for private power generation equipment. 4. Distribution from the grid power company that supplies power
Power is supplied through the power line, and the
Power generator with a private load that is supplied with power
Installed between the distribution line on the grid power side and the private generator.
And second current detection provided in series with a branch line
At the junction between the detector and the first and second current detectors in the branch line.
Detector is a resistor connected through a switch
And the peak value of the current flowing through the first current detector on the distribution line side.
The peak of the current flowing through the first current peak value detector to be detected and the current flowing through the second current detector on the private generator side.
A second current peak value detector for detecting the peak value and a first or second current peak value detector when the switch is off.
Peak value of detected current and first current at switch-on
Predetermined difference from peak value of current detected by peak value detector
If the value is larger than the value of
System is judged to be healthy and normal, and
The peak of the current detected by the first or second current peak value detector.
The peak current and the second current peak value detector at switch-on
If the difference from the detected current peak value is larger than a predetermined value
Kiha's private power generation equipment is unhealthy during interconnection with the grid power company
Judgment that the private power generation equipment is operating alone
A private operation determination unit that performs
An isolated operation detection device for power generation equipment.