JP2007312445A - Management system for insulation monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform precision test of an insulation monitoring device under a hot-line state of electric path while reducing the burden of work required for precision test of the insulation monitoring device. <P>SOLUTION: In the management system for an insulation monitoring device comprising an insulation monitoring device IO for monitoring insulation of an electric path based on the detection information of a zero-phase current sensor, and a test current generator 5 feeding a test current for performing precision test of the insulation monitoring device IO, a management server computer CS for managing the operating state of the insulation monitoring device IO from a remote place through a communication line CL is provided. The insulation monitoring device IO is arranged to transmit the detection information of insulating state of the electric path to the management server computer CS through the communication line CL, and test wiring 8 for feeding a test current is sustained in a state fixed to a fixing position for conducting the test current regardless of whether precision test of the insulation monitoring device IO is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an insulation monitoring device that performs insulation monitoring of the electric circuit based on detection information of a zero-phase current detection sensor that detects a zero-phase current of a single-phase AC circuit or a three-phase AC circuit whose one line is grounded, The present invention relates to a management system for an insulation monitoring device provided with a test current generator that supplies a test current for performing an accuracy test of the insulation monitoring device.

Such a management system for an insulation monitoring device is a system for managing whether or not an insulation monitoring device such as that described in Patent Document 1 below can properly monitor the insulation state of the electric circuit.
Conventionally, as an operation for managing whether or not the insulation monitoring device is operating properly, an inspection engineer visits the installation location of the insulation monitoring device periodically (for example, once a year). An accuracy test was conducted.
The test procedure of the accuracy test of the insulation monitoring device will be briefly described. First, the electric circuit that is the monitoring target of the insulation monitoring device is blacked out, and the zero-phase current detection sensor of the insulation monitoring device is removed from the detection target portion in the electric circuit. .
Further, the removed zero-phase current detection sensor is connected so that the test current generated by the test current generator is detected, and the insulation monitoring device is controlled according to the test current supplied from the test current generator. Check whether to perform the operation.
Thereafter, the zero-phase current detection sensor is attached to the detection target location in the electric circuit, and the electric circuit is restored from the power failure to the normal state, thereby completing the operation.
JP 2002-125313 A

Therefore, in the above-described conventional configuration, it is necessary for an inspection engineer to go to the installation location of the insulation monitoring device, which increases the work load for the management of the insulation monitoring device, and causes the power circuit to be monitored by power failure. The work that receives power supply from the company will be stopped.
The present invention has been made in view of such circumstances, and its purpose is to reduce the work burden required for the accuracy test of the insulation monitoring device as much as possible and to perform insulation monitoring while keeping the electric circuit in a live line state. The point is to be able to test the accuracy of the equipment.

  The first invention of the present application is an insulation that monitors insulation of the electric circuit based on detection information of a zero-phase current detection sensor that detects a zero-phase current of a single-phase AC circuit or a three-phase AC circuit whose one line is grounded. In a management system for an insulation monitoring device provided with a monitoring device and a test current generator for supplying a test current for performing an accuracy test of the insulation monitoring device, the operation state of the insulation monitoring device is communicated from a remote location A management server computer for management via a line, and the insulation monitoring device is configured to transmit the detection information of the insulation state of the electric circuit to the management server computer via the communication line, and to generate the test current The test wiring for supplying the test current generated by the apparatus uses the test current for the accuracy test of the insulation monitoring device regardless of whether the accuracy test of the insulation monitoring device is performed or not. The test current generator is maintained in a state where it is attached to an attachment position for electricity, and the test current generator is a test set in advance by a test start command sent from the management server computer via the communication line. The test current is made to flow according to a schedule.

That is, the accuracy test of the insulation monitoring device that tests whether the insulation monitoring device detects the test current properly by supplying the test current generated by the test current generator from a remote location via a communication line Managed by server computer.
The test current generator is used for testing regardless of whether or not the insulation monitoring device accuracy test is performed so that a series of accuracy tests are performed without dispatching an inspection engineer to the installation location of the insulation monitoring device. It is installed in a state where it is maintained in a connection state that allows current to flow, and since it is possible to flow a test current at any time for the accuracy test of the insulation monitoring device, it requires no human power to pass the test current. In addition, there is no need to power out the monitored circuit.

The accuracy test of the insulation monitoring device is generally performed periodically, but the start timing of the accuracy test can be instructed from the management server computer to the test current generator via the communication line. The accuracy test can be started with a preset test schedule by providing a calendar function or the like on the test current generator side.
Further, the setting of the current value of the test current can also be instructed from the management server computer to the test current generator via the communication line, and the current value of the test current is sent to the test current generator side. Can be set in advance.

  The insulation monitoring device detects the insulation state of the electric circuit in the state where the test current is flowing, and how the insulation monitoring device operates as the test current flows on the management server computer side By acquiring the information regarding whether or not it has been performed through the communication line, it is possible to acquire the same information as in the case of performing an accuracy test without dispatching an inspection engineer to the installation location of the insulation monitoring device.

  According to a second invention of the present application, in addition to the configuration of the first invention, the insulation monitoring device detects, based on detection information of the zero-phase current detection sensor, as detection information of an insulation state of the electric circuit. An alarm indicating that the current value is larger than a set current value and a detected current value at that time are configured to be transmitted to the management server computer via the communication line, and the management server computer is Based on the target current value to be detected by the insulation monitoring device by flowing the test current and the detection information of the insulation state of the electric circuit sent from the insulation monitoring device when the test current is supplied. The insulation monitoring device is configured to determine whether or not it is operating properly.

In other words, the management server computer operates the insulation monitoring device properly from the target current value and the detected current value sent from the insulation monitoring device with the test current generated by the test current generator flowing. Determine whether you are doing.
For information on the target current value to be detected by the insulation monitoring device by flowing a test current, when the management server computer indicates the target current value, the information is held by itself. In the case where the test current generator sets the target current value independently, the target current value set by the test current generator may be obtained via the communication line.

According to a third invention of the present application, in addition to the configuration of the first or second invention, a target current value to be detected by the insulation monitoring device by flowing the test current, and the test current are set. An operation state determination device is provided for determining whether or not the insulation monitoring device is operating properly based on the detection information of the insulation state of the electric circuit by the insulation monitoring device when flowing; The apparatus is configured to transmit a determination result as to whether or not the insulation monitoring apparatus is operating properly to the management server computer via the communication line.
That is, a configuration in which the determination function as to whether or not the insulation monitoring device is operating properly is provided on the installation location side of the insulation monitoring device, and the management server computer acquires the result determined through the communication line In this way, the insulation monitoring device is managed.

  According to a fourth invention of the present application, in addition to the configuration of any of the first to third inventions, the insulation monitoring device extracts a resistive current component included in the zero-phase current. It is configured to monitor insulation of the electric circuit, and the test current generator is configured to detect the detection information of the zero-phase current and the resistive current component to be detected by the insulation monitor by flowing the test current. When adding the resistive current component included in the zero-phase current based on the target current value and the reference phase information set in advance as information for specifying the phase of the resistive current component And generating the test current from which a target current value of the resistive current component is obtained.

That is, as shown in FIG. 7, the zero-phase current Io is divided into a resistive current component Ir in phase with the voltage V and a capacitive current component having a phase difference of 90 ° from the resistive current component by the vector symbol method. Since it is expressed as a vector sum with Ic, if information for specifying the phase of the voltage V measured by various methods (that is, the phase of the resistive current component Ir) is given as the reference phase information, zero A resistive current component Ir, that is, a pure ground fault current can be obtained from the amplitude and phase of the phase current Io and the reference phase information.
When the insulation monitoring device monitors the insulation of the circuit, and when performing the accuracy test of the insulation monitoring device, the resistance current contained in the zero-phase current is not a simple zero-phase current value. By detecting by paying attention to the components, the insulation monitoring of the electric circuit by the insulation monitoring device can be performed with high detection accuracy, and the accuracy test of the insulation monitoring device can be performed with high accuracy.
Moreover, there is no problem even if the wiring connection of the test current generator for performing the accuracy test of the insulation monitoring device in such a form is maintained even in a normal monitoring state other than when performing the accuracy test, The compatibility with the accuracy test of the insulation monitoring device without dispatching an inspection engineer is very good.

  According to the first aspect of the present invention, on the installation location side of the insulation monitoring device, no manual operation is required for energizing the test current, and it is not necessary to cause a power failure of the monitoring target electric circuit, so that the management server computer side Then, an inspection engineer is dispatched to the location where the insulation monitoring device is installed by acquiring information on how the insulation monitoring device has been operated as a test current flows through the detection target location via the communication line. Even if you do not, you can obtain the same information as when you sent the accuracy test, so you can reduce the work load required for the accuracy test of the insulation monitoring device as much as possible, and keep the electric circuit in a live state It became possible to test the accuracy of the insulation monitoring device.

According to the second aspect of the invention, the management server computer mainly takes the information on the installation location side of the insulation monitoring device and judges whether the insulation monitoring device is operating properly. On the management server computer side, the state on the installation location side of the insulation monitoring device can be accurately managed.
According to the third aspect of the present invention, the function of determining whether or not the insulation monitoring device is operating properly is provided on the installation location side of the insulation monitoring device. The load can be reduced.
Further, according to the fourth aspect of the invention, it is possible to manage the detection accuracy of the insulation monitoring device with the management server computer with high accuracy.

Embodiments of a management system for an insulation monitoring apparatus according to the present invention will be described below with reference to the drawings.
<First Embodiment>
The high voltage of 6.6 kV drawn into the power receiving / distributing facility from the distribution line by the lead-in line as shown in FIG. 1 schematically showing the connection form of the equipment in the vicinity of the power receiving / distributing facility of the power consumer is a transformer. It is transformed into low voltage such as 200V 3-phase 3-wire, single-phase 3-wire, or 100V single-phase 2-wire by TR.
The secondary side (low voltage side) of the transformer TR is grounded by a class B ground wire. For example, for a three-phase three-wire, one phase of the three-phase wires is grounded.
A zero-phase current transformer 1 which is a zero-phase current detection sensor ZT for detecting a zero-phase current is attached to the ground line EL. Further, based on the detection information of the zero-phase current transformer 1, the electric circuit is insulated. An insulation monitoring device IO for monitoring is provided.
The operation state of the insulation monitoring device IO is managed via the communication line CL by the management server computer CS of the monitoring center OC located at a remote location, and the insulation monitoring device IO receives the detection information of the insulation state of the electric circuit to be monitored. It is configured to transmit to the management server computer CS.

[Configuration of insulation monitoring device IO]
The insulation monitoring device IO includes a ground-fault current detection device 2 that detects a ground-fault current based on detection information of the zero-phase current transformer 1, and a ground-fault current that causes the ground-fault current detection device 2 to be larger than a set current value. Alarm signal output device 3 for outputting an alarm signal to various alarm devices when it is detected, the server computer CS for management of the monitoring center OC where the insulation monitoring device IO exists at a remote location, and the communication line CL A communication circuit 4 for communicating through the test circuit, a test current generator 5 for generating a test current for performing an operation test (accuracy test) of the ground fault current detector 2, and an operation test of the ground fault current detector 2 And a test control device 6 for controlling execution.
The test current generated by the test current generator 5 is supplied to the detection target portion of the zero-phase current transformer 1 through the test winding 7 that is passed (wound) through the zero-phase current transformer 1.
The test wiring 8 for passing a test current from the terminal of the test current generator 5 to the test winding 7 is schematically shown in FIG. 1 when the insulation monitoring device IO is installed on site to monitor the insulation of the electric circuit. The insulation monitoring device IO is attached to an attachment position for supplying a test current for the accuracy test of the insulation monitoring device IO, and thereafter the attachment is performed regardless of whether or not the accuracy test of the insulation monitoring device IO is performed. Maintained.

The ground fault current detection device 2 extracts a current component (resistive current component) in phase with the voltage to be monitored from the detected current of the zero-phase current transformer 1 by vector calculation.
As a specific method for extracting the resistive current component, the phase difference between the phase of the zero-phase current and the voltage phase is detected, and the resistance component of the zero-phase current is calculated from the phase difference (angle). Alternatively, as described in Patent Document 1, a vector calculation may be performed using a phase determination signal generated from a line voltage.
The operation of the ground fault current detection device 2 is also described in the description of the accuracy test of the insulation monitoring device IO described later.

  As shown in the block diagram of FIG. 2, the test current generator 5 receives from the ground-fault current detector 2 the converted zero-phase current detected by the zero-phase current transformer 1 as a voltage signal and receives a high-frequency component. And a control target of the total current flowing through the detection target location of the zero-phase current transformer 1 (the current obtained by adding the current flowing through the ground line EL and the current flowing through the test winding 7). A sine wave generation circuit 22 for performing the operation, an amplitude setting circuit 23 for setting the amplitude of the sine wave voltage generated by the sine wave generation circuit 22 in accordance with the target current value It sent from the test control device 6, and a low-pass An operational amplifier circuit 24 (so-called operational amplifier) having the output of the filter 21 and the output of the sine wave generation circuit 22 as inputs, and a phase indication circuit for setting the phase of the sine wave voltage generated by the sine wave generation circuit 22 25, a zero-crossing phase detection circuit 26 for detecting the voltage phase of the target location for insulation monitoring, a zero-crossing phase detection circuit 27 for detecting the voltage phase of an AC power supply used as an operation power supply for the insulation monitoring device IO, and a zero-crossing A phase difference detection circuit 28 is provided which calculates the difference between the phase detection circuits 26 and 27 to obtain the phase difference between them.

The operational amplifier circuit 24 is formed with a feedback circuit having the test winding 7, the zero-phase current transformer 1, the ground fault current detection device 2, and the low-pass filter 21 as a feedback loop path.
Therefore, the operational amplifier circuit 24 controls the test current so that the input signal from the low-pass filter 21 and the input signal from the sine wave generation circuit 22 match.
The amplitude setting circuit 23 has an effective value of “It” based on the conversion characteristic of converting the zero-phase current into voltage in the ground fault current detection device 2 when the target current value It is instructed from the test control device 6. A sine wave is generated so as to generate a sine wave voltage having an amplitude matching the zero phase current detection signal sent from the ground fault current detection device 2 to the low pass filter 21 when the zero phase current transformer 1 detects the sine wave current. The generation circuit 22 is instructed.
The frequency of the sine wave voltage generated by the sine wave generation circuit 22 is matched with the frequency of the voltage to be monitored.
The phase of the sine wave voltage generated by the sine wave generation circuit 22 is set by a phase indication circuit 25, zero-cross phase detection circuits 26 and 27, and a phase difference detection circuit 28.
That is, when the insulation monitoring device IO is installed, the phase difference between the voltage of the monitored electric circuit and the voltage of the AC power supply used as the operation power supply of the insulation monitoring device IO is used as the reference phase information in the phase indicating circuit 25. The sine wave generation circuit 22 is configured to generate a sine wave voltage having a phase that matches the voltage phase of the monitoring target electric circuit from the voltage phase of its own operation power supply and the stored phase difference. Outputs phase indication signal.
The reference phase information stored in the phase indication circuit 25 is an integer multiple of 30 ° depending on the connection method of the voltage device from the monitoring target circuit to the power source for operation of the insulation monitoring device IO. It is unchanged unless the wiring is changed.

By configuring the test current generator 5 in this way, the detection target location of the zero-phase current transformer 1 is the result of adding the original zero-phase current and the test current supplied to the test winding 7 together. Since the sine wave current flows and the phase of the sine wave current coincides with the voltage phase of the circuit to be monitored, the sine wave current detected by the zero-phase current transformer 1 is a resistive current component. It will be composed only of.
Summarizing the generation process of this test current, the test current generator 5 detects the zero-phase current detection information and the target current of the resistive current component applied to the insulation monitoring device IO by flowing the test current. Based on the value It and the reference phase information that is information for specifying the phase of the resistive current component, the resistive current component included in the zero-phase current (zero-phase current of the ground line EL) This means that a test current that produces the target current value It when it is added is generated.
From the above, the sine wave generation circuit 22, the amplitude setting circuit 23, and the phase indication circuit 25 generate the target sine wave that generates a sine wave having the amplitude and phase set based on the target current value It and the reference phase information. The operational amplifier circuit 24 functions as a wave generation means, and the operational amplifier circuit 24 uses the detection information of the zero-phase current at the detection target portion and the sine wave generated by the target sine wave generation means as inputs, and tests so that the two inputs coincide Generate current.

[Operation test of insulation monitoring device IO]
The operation test of the insulation monitoring device IO is executed under the management of the management server computer CS of the monitoring center OC.
The monitoring center OC periodically performs an accuracy test on a number of insulation monitoring devices IO under management, and the management server computer CS periodically performs an operation test process shown in FIG.
When the processing of FIG. 3 is started, first, a signal (test start command) for starting the accuracy test of the insulation monitoring device IO is transmitted from the management server computer CS to the test control device 6 (step #). 1).
When the test control device 6 receives this signal via the communication circuit 4, the test control device 6 causes the alarm signal output device 3 of the insulation monitoring device IO to stop outputting the alarm signal.
Of course, the monitored electric circuit is maintained in a live state without being interrupted.

Next, the management server computer CS transmits an initial value of the target current value It to be detected by the insulation monitoring device IO by flowing a test current to the test control device 6 (step # 2). As described above, the target current value It in the first embodiment is the insulation monitoring device IO when the test current generated by the test current generator 5 is passed through the detection target location of the zero-phase current transformer 1. This is the target current value It of the resistive current component related to the detection of. The initial value of the target current value It is set to a value that is sufficiently smaller than the current value that the insulation monitoring device IO detects that a ground fault has occurred.
Each time the test control device 6 receives update data of the target current value It from the management server computer CS, the test control device 6 sends the received data of the target current value It to the amplitude setting circuit 23 of the test current generator 5 for testing. The amplitude of the current is set, and accordingly, a test current is generated by the test current generator 5 as described above and supplied to the test winding 7.
As an operation of insulation monitoring in the insulation monitoring device IO, except for the point that the warning signal output device 3 stops outputting the warning signal, this accuracy test also operates completely the same as the operation in normal insulation monitoring. The ground fault current detection device 2 is a combined current of a resistive current component in phase with the voltage phase of the circuit to be monitored and a capacitive current component that is 90 ° out of phase with the resistive current component. A resistive current component is extracted from the detected current of the zero-phase current transformer 1 by vector calculation. When the resistive current component is smaller than a set current value (for example, several tens of mA), nothing is done. When it is detected that the current value is larger than the set current value, an alarm indicating that is sent to the alarm signal output device 3 and also sent to the management server computer CS via the communication circuit 4. Furthermore, the detected current value at that time is also sent to the management server computer CS.

On the management server computer CS side, the target current value It instructed to the test control device 6 is gradually increased within a range not exceeding the upper limit value of the test current (steps # 4 and # 5), and the ground fault current Monitors whether the detection device 2 outputs an alarm (strictly, a signal indicating that the detected resistive current component has become larger than the set current value) (step # 3), and outputs an alarm Then, the test control device 6 is instructed to stop generating the test current (step # 6), and it is determined whether or not the detection accuracy of the insulation monitoring device IO is appropriate based on the detected current value sent together with the alarm. (Step # 7).
That is, the target current value It instructed to the test control device 6 at the time when an alarm is sent from the insulation monitoring device IO (more specifically, the ground fault current detection device 2), and the ground fault current detection device 2 If the difference between the two is within the allowable range, the insulation monitoring device IO is determined to be operating properly with sufficient accuracy, and the allowable range is determined. If it exceeds, it is determined that the detection accuracy of the insulation monitoring device IO is not sufficient and is not operating properly.
The determination result is displayed on the monitor of the management server computer CS (step # 8), and when it is determined that the detection accuracy of the insulation monitoring device IO is not sufficient, the monitoring center OC A person is dispatched to the installation location of the insulation monitoring device IO to take necessary measures.
When the test control device 6 receives an instruction to stop generation of the test current from the management server computer CS, the test control device 6 stops the operation of the test current generator 5 and allows the alarm signal output device 3 to output an alarm signal. Return to the state.
Further, when the target current value It reaches the upper limit without receiving an alarm from the ground fault current detection device 2 in the process of gradually increasing the target current value It as described above. (Step # 4) In the same manner as described above, the supply of the test current is stopped (Step # 6), and it is determined whether or not the detection accuracy of the insulation monitoring device IO is appropriate (Step # 7). Of course, it is determined that the detection accuracy is abnormal.

In the above, the current that flows through the detection target location for the detection of the zero-phase current transformer 1 in a state where the test current generated by the test current generator 5 is passed through the test winding 7 (the test current and the original current). The case where the current is the sum of the zero-phase currents) is the same phase as the voltage phase of the circuit to be monitored and is configured as a sine wave current having only a resistive current component. The phase to be shifted may be shifted from the voltage phase to some extent. Even when the phase is shifted in this way, the amplitude setting circuit 23 generates a phase so that the resistive current component of the current applied to the detection of the zero-phase current transformer 1 becomes the target current value It. The amplitude of the sine wave voltage is set to be large according to the deviation.
Even if the test current is supplied so that the phase-shifted current is detected by the zero-phase current transformer 1, the function of extracting the resistive current component of the ground fault current detecting device 2 functions properly. If so, the same result as the above test should be obtained, and the function of the ground fault current detection device 2 can be checked in a wider range.

Furthermore, a test that is performed by matching the phase of the current applied to the detection of the zero-phase current transformer 1 with the voltage phase to be monitored and supplying only the resistive current component to the test winding, and the zero-phase current transformer 1 The test may be performed more strictly by performing both the test performed by shifting the phase of the current applied to the detection from the voltage phase to be monitored and supplying it to the test winding.
In the process of FIG. 3, a command for gradually changing the target current value It is transmitted from the management server computer CS in order to gradually change the current value of the current flowing through the detection target portion. The setting change of the target current value It may be left to the equipment on the insulation monitoring device IO side such as the test control device 6.
Even in this case, the management server computer CS can acquire the target current value It information by sequentially receiving the target current value It information from the test control device 6.

Second Embodiment
In the first embodiment, the case where the test current is generated so that the current value as a result of adding the test current to the current originally flowing in the detection target portion of the zero-phase current transformer 1 becomes the target current value It is described. Although illustrated, in the second embodiment, when a test current is passed through the test winding 7 for an accuracy test of the insulation monitoring device IO, the current that originally flows through the ground line EL is not affected. ing.
In the second embodiment, as shown in FIG. 4 schematically showing the connection form of equipment in the vicinity of the power supply / distribution facility of the power consumer, a test winding is provided separately from the zero-phase current transformer 1 for insulation monitoring. A test zero-phase current transformer 31 that passes only (wound) the wire 7 is provided, and either the zero-phase current transformer 1 for monitoring insulation or the zero-phase current transformer 31 for testing is selected. In particular, a switch 32 for connection to the ground fault current detection device 2 is provided.
In the normal insulation monitoring operation, the switch 32 connects the wiring from the insulation monitoring zero-phase current transformer 1 for detecting the ground wire EL to the ground fault current detection device 2 under the control of the test control device 6. Only when the accuracy test of the insulation monitoring device IO is performed, the switching operation is performed so that the wiring from the test zero-phase current transformer 31 is connected to the ground fault current detection device 2.
Also in the second embodiment in which such wiring is performed, the test wiring 8 for supplying the test current from the terminal of the test current generator 5 to the test winding 7 is insulated for monitoring the insulation of the electric circuit. When the device IO is installed in the field, it is attached to an attachment position for supplying a test current for an accuracy test of the insulation monitoring device IO schematically shown in FIG. Regardless of whether or not the accuracy test is performed, the attached state is maintained.

As described above, the test current generator 5 includes the test zero-phase current transformer 31 that is not affected by the current flowing through the ground line EL and performs the accuracy test of the insulation monitoring device IO. The configuration is also different from that of the first embodiment.
That is, the test current generator 5 in the second embodiment includes a sine wave current generation circuit 41 that generates a sine wave current to be supplied to the test winding 7 as a test current, as shown in the block diagram of FIG. A gain adjustment circuit 42 that adjusts the amplitude of the sine wave current generated by the sine wave current generation circuit 41 based on the target current value It instructed from the test control device 6, and a sine wave generated by the sine wave current generation circuit 41. In addition to the phase indicating circuit 25 for setting the phase of the current, the shunt resistor 43 for monitoring the sine wave current output from the sine wave current generating circuit 41, and the zero cross for detecting the voltage phase of the target location for insulation monitoring A phase detection circuit 26, a zero-cross phase detection circuit 27 for detecting the voltage phase of an AC power source used as an operation power source for the insulation monitoring device IO, and a zero-cross phase detection A phase difference detection circuit 28 for determining the phase difference between taking the difference between the circuits 26 and 27 are provided.
The zero-crossing phase detection circuits 26 and 27, the phase difference detection circuit 28, and the phase instruction circuit 25 denoted by the same reference numerals as those in the first embodiment are the same as those in the first embodiment.

The gain adjustment circuit 42 adjusts the amplitude of the sine wave current waveform so that the effective value of the sine wave current (current monitored by the shunt resistor 43) output from the sine wave current generation circuit 41 becomes the target current value It. adjust.
The frequency of the sine wave current generated by the sine wave current generation circuit 41 matches the frequency of the voltage to be monitored, and the phase is designated by the phase indication circuit 27.
Accordingly, also in the second embodiment, since the phase of the sine wave current matches the voltage phase of the monitored electric circuit, the sine wave current required for detection by the test zero-phase current transformer 31 is resistant. It is comprised only by the current component.
Of course, the point that the phase of the sine wave current may be intentionally shifted is the same as in the first embodiment.

The operation of the management server computer CS when performing an accuracy test on the insulation monitoring device IO configured as described above is the same as that in the first embodiment, and the operation test process of the flowchart of FIG. 3 is performed. By executing, the detection accuracy of the insulation monitoring device IO is determined as described above.
In the accuracy test of the insulation monitoring device IO, the difference from the first embodiment is that, in the control of the test control device 6, when a signal indicating that the test in step # 1 in FIG. 3 is started is received from the management server computer CS. In addition, the connection state of the switch 32 is changed from the state in which the zero-phase current transformer 1 for monitoring insulation is connected to the ground-fault current detector 2 to the connection of the test zero-phase current transformer 31 to the ground-fault current detector 2. When an instruction to stop the generation of the test current in step # 6 in FIG. 3 is received from the management server computer CS, the connection state of the switch 32 is changed to the test state. Switching from the state in which the zero-phase current transformer 31 is connected to the ground-fault current detection device 2 to the state in which the zero-phase current transformer 1 for monitoring insulation is connected to the ground-fault current detection device 2 is performed to perform a normal insulation monitoring operation. Reinstate Operation is a point to join.

<Third Embodiment>
In the first embodiment and the second embodiment, the management server computer CS determines whether or not the operation of the insulation monitoring device IO is appropriate according to the flowchart of FIG. 3 executed by the management server computer CS. Although the case where it performs is illustrated, in this 3rd Embodiment, the determination function whether the operation | movement of insulation monitoring apparatus IO is appropriate shall be provided in the insulation monitoring apparatus IO side.
Specifically, the test control device 6 executes the process shown in FIG.
The operations of other components are the same as those in the first embodiment or the second embodiment. The test control device 6 and the management server computer CS in the first embodiment, and the second embodiment. The test control device 6 and the management server computer CS can be replaced by the test control device 6 and the management server computer CS described below.

When the test control device 6 receives a command (test start command) for starting the accuracy test of the insulation monitoring device IO from the management server computer CS, the test control device 6 starts the process of FIG.
First, the alarm signal output device 3 is set not to output an alarm signal (step # 21). At this time, when configured as shown in FIG. 4 of the second embodiment, the connection state of the switch 32 is changed from a state in which the zero-phase current transformer 1 for insulation monitoring is connected to the ground fault current detection device 2. The test zero-phase current transformer 31 is switched to a state where it is connected to the ground fault current detection device 2.
Thereafter, the target current value It is initialized (step # 22), and supply of test current to the test winding 7 is started by starting energization of the test current generator 5 (step # 23). . Thereafter, while gradually increasing the target current value It (step # 26), the ground fault current detecting device 2 gives an alarm (strictly, the resistance current component indicates that it is larger than the set current value). Signal) is output (step # 24), and when an alarm is output, energization of the test current generator 5 is stopped and the supply of test current is stopped (step # 27). It is determined whether or not the operation of the insulation monitoring device IO is appropriate based on the target current value It (step # 28).

In determining whether the operation of the insulation monitoring device IO is appropriate, the ground fault current detection device 2 is configured to output the detected current value at that time to the test control device 6 together with the above-described alarm, The detected current value is compared with the target current value It, and if the difference between the two is within an allowable range, it is determined that the insulation monitoring device IO is operating with sufficient accuracy, and the allowable range is exceeded. If so, it is determined that the detection accuracy of the insulation monitoring device IO is not sufficient.
Of course, the ground fault current detection device 2 does not output the detected current value, but outputs only the above-mentioned alarm, so that the insulation is only performed depending on at which point the alarm is output in the process of finely changing the target current value It. It may be determined whether the detection accuracy of the monitoring device IO is sufficient.
Therefore, the test control device 6 detects the target current value It detected by the insulation monitoring device IO by flowing the test current, and detection information (specifically, the insulation state of the electric circuit by the insulation monitoring device IO when the test current is supplied). Specifically, it functions as an operation state determination device JO that determines whether or not the insulation monitoring device IO is operating properly based on the detected current value of the ground fault current detection device 2 or the alarm).

The result of the determination as to whether or not the insulation monitoring device IO is operating properly is transmitted from the communication circuit 4 to the management server computer CS via the communication line CL (step # 29), and then the alarm signal output device. 3 returns to the setting for outputting an alarm signal (step # 30), and the process is terminated.
In this case, when the second embodiment is configured as shown in FIG. 4, the connection state of the switch 32 is insulated from the state in which the test zero-phase current transformer 31 is connected to the ground fault current detection device 2. The monitoring zero-phase current transformer 1 is switched to a state in which it is connected to the ground-fault current detector 2.
The determination result sent to the management server computer CS in step # 29 of the process of FIG. 6 is displayed on the monitor of the management server computer CS, and it is determined that the detection accuracy of the insulation monitoring device IO is not sufficient. Is displayed, the monitoring center OC dispatches an engineer to the installation location of the insulation monitoring device IO to take necessary measures.

<Other embodiments>
Hereinafter, other embodiments of the present invention will be listed.
(1) In the first to third embodiments, the resistive current component included in the zero-phase current is extracted, and the insulation monitoring by the insulation monitoring device IO and the accuracy test of the insulation monitoring device IO are performed. Although illustrated, the insulation monitoring by the insulation monitoring device IO and the accuracy test of the insulation monitoring device IO may be performed simply by the absolute value of the zero-phase current.
(2) In the first to third embodiments, the zero-phase current transformer 1 is exemplified as the zero-phase current detection sensor ZT. However, a current transformer is used if it has sufficient sensitivity. Also good.
The same applies to the zero-phase current transformer 31 in the second embodiment.
(3) In the first to third embodiments, the case where the test current generating device 5 is built in the insulation monitoring device IO is illustrated, but the test current generating device 5 is separate from the insulation monitoring device IO. You may make it provide as an independent apparatus.
(4) In the first to third embodiments described above, the case where the monitored electric circuit is a three-phase three-wire AC is illustrated, but a single-phase three-wire that grounds a neutral wire with a ground wire EL The present invention can also be applied to the case where the insulation monitoring is performed on an alternating current circuit or a single-phase two-wire AC circuit in which one of the two wires is grounded by the ground wire EL.

(5) In the above first to third embodiments, the case where the detection target portion of the zero-phase current detection sensor ZT is the ground line EL is illustrated, but any position that can detect the zero-phase current is arbitrary. May be the detection target location of the zero-phase current detection sensor ZT.
(6) In the first embodiment, the detection information of the zero-phase current transformer 1 of the insulation monitoring device IO is acquired in order to obtain the detection information of the zero-phase current. A phase current detection sensor may be provided.
(7) In the first to third embodiments, the target current value It is specified as an effective value. However, the target current value It is not necessarily an effective value.
(8) In the first to third embodiments, a case where the operation test of the insulation monitoring device IO is performed by a test start command from the monitoring center OC is illustrated. The test current generator 5 generates a test current and stores a test schedule for performing an operation test of the insulation monitoring device IO, and the test control device 6 voluntarily monitors the insulation according to the test schedule. The operation test of the device IO may be performed, and the result may be reported to the management server computer CS of the monitoring center OC.

1 is an overall block configuration diagram according to a first embodiment of the present invention. The block block diagram of the test current generator concerning 1st Embodiment of this invention. The flowchart concerning 1st Embodiment and 2nd Embodiment of this invention Whole block block diagram concerning 2nd Embodiment of this invention. The block block diagram of the test current generator concerning 2nd Embodiment of this invention. The flowchart concerning 3rd Embodiment of this invention. The figure explaining the resistive current component contained in the zero phase current

Explanation of symbols

CL communication line CS management server computer IO insulation monitoring device JO operation state determination device ZT zero-phase current detection sensor 5 test current generator 8 test wiring

Claims (4)

An insulation monitoring device that performs insulation monitoring of the electric circuit based on detection information of a zero-phase current detection sensor that detects a zero-phase current of a single-phase AC circuit or a three-phase AC circuit in which one wire is grounded;
A management system for an insulation monitoring device provided with a test current generator for supplying a test current for performing an accuracy test of the insulation monitoring device,
A management server computer for managing the operating state of the insulation monitoring device from a remote location via a communication line;
The insulation monitoring device is configured to transmit detection information of an insulation state of the electric circuit to the management server computer via the communication line,
The test wiring for supplying the test current generated by the test current generator is used for the accuracy test of the insulation monitoring device regardless of whether or not the accuracy test of the insulation monitoring device is performed. Maintained in the mounting position for energizing the
The test current generator is configured to cause the test current to flow according to a test start instruction sent from the management server computer via the communication line or according to a preset test schedule. Management system for insulation monitoring equipment. The insulation monitoring device includes an alarm indicating that a detected current value based on detection information of the zero-phase current detection sensor is larger than a set current value as detection information of the insulation state of the electric circuit, and a detected current value at that time And is transmitted to the management server computer via the communication line,
The management server computer has a target current value to be detected by the insulation monitoring device by flowing the test current, and an insulation state of the electric circuit sent from the insulation monitoring device when the test current is flowed The management system for an insulation monitoring device according to claim 1, wherein the management system is configured to determine whether or not the insulation monitoring device is operating properly based on the detected information. Based on a target current value to be detected by the insulation monitoring device by flowing the test current, and detection information of the insulation state of the electric circuit by the insulation monitoring device when the test current is supplied. An operation state determination device for determining whether or not the device is operating properly is provided,
The operation state determination device is configured to transmit a determination result as to whether or not the insulation monitoring device is operating properly to the management server computer via the communication line. Management system for insulation monitoring equipment. The insulation monitoring device is configured to extract a resistive current component included in the zero-phase current and perform insulation monitoring of the electric circuit,
The test current generator includes detection information of the zero-phase current, a target current value of the resistive current component that is detected by the insulation monitoring device by flowing the test current, and a current value of the resistive current component. Based on the reference phase information set in advance as information for specifying the phase, the target current value of the resistive current component is obtained when added to the resistive current component included in the zero-phase current. The management system for an insulation monitoring apparatus according to any one of claims 1 to 3, wherein the management system is configured to generate the obtained test current.

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