JP7204450B2 - INSULATION RESISTANCE TEST SYSTEM AND INSULATION RESISTANCE TEST METHOD - Google Patents

Description

The present invention relates to an insulation resistance test system and an insulation resistance test method.

A photovoltaic power generation system sends direct-current power generated by a solar cell device to a power converter (power conditioner) via a power cable, and the power converter converts the direct-current power into alternating-current power. An insulation resistance test using an insulation resistance tester is performed to detect a ground fault condition that has occurred on the DC side of a solar cell device and a power conversion device.
By the way, there is a power conversion device that has a relatively small capacity but has main functions in a small housing. For example, in such a power conversion device, there is a power conversion device in which the connecting portion of the power cable is connector-connected to facilitate attachment and detachment of the power cable.

JP 2012-146931 A

However, even if the power cable connected to the solar cell device is removed from the connector of the power conversion device, it may be difficult to see the electrodes provided in the connector of the power conversion device, and the insulation resistance test is performed. The workability at the time of implementation sometimes deteriorated.

The present invention has been made in view of the above circumstances, and aims to provide an insulation resistance test system and an insulation resistance test method that can improve maintainability when performing an insulation resistance test of a photovoltaic power generation system. aim.

(1) In order to solve the above problems, one aspect of the present invention provides insulation of a test target range of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device. An insulation resistance test system for performing a resistance test, which tests the insulation resistance of the test target range using the power conversion device of the solar power generation system and an insulation resistance meter that outputs a test voltage. and an insulation resistance test support device for supporting work , wherein the power conversion device includes a power converter main body provided in a housing, and a first power cable connected to the first solar cell device. A second power cable connected to a first input terminal to which a plug is provided and the first plug is connected, and a second power cable connected to the second solar cell device is provided with a second plug to which the second plug is connected. 2 input terminals, a first connection conductor that connects the first input terminal and the second input terminal inside the housing of the power conversion device, and the first connection conductor as an input of the power converter body. and a second connection conductor that is provided on the second connection conductor and electrically connects between the first connection conductor and the input side of the power converter body at least when an insulation resistance test is performed. a switch that cuts off, the insulation resistance test support device comprising: a first connection cable having a connection plug that can be fitted to the first input terminal at a first end; and the first connection cable. is connected to a terminal to which the second end is electrically connected, the insulation resistance meter and the terminal, and the test voltage for the insulation resistance test of the second solar cell device and the second power cable is applied to the terminal The insulation resistance test support device is an insulation resistance test system arranged between the insulation resistance meter and the test target range.

(2) In addition, in the insulation resistance test support device, the first input terminal is provided at the bottom of the housing of the power converter when the power converter is placed in an operable state, and the connection the plug is connected and
The first connection cable is provided at the bottom of the housing of the power conversion device, the connection plug is connected, and the length of the first connection cable approximates the shape of the housing of the power conversion device to a rectangular parallelepiped, and the side of the rectangular parallelepiped longer than the shortest side of

(3) In addition, the insulation resistance test support device further includes a box-shaped support, and the test terminal is arranged on the top surface or side surface of the support in a state where the connection plug is connected to the first input terminal. be done.

(4) Further, the insulation resistance measuring method of one aspect of the present invention provides a test range of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device. An insulation resistance test method by an insulation resistance test system for testing insulation resistance, wherein the insulation resistance test system uses a power conversion device of the solar power generation system and an insulation resistance meter that outputs a test voltage to the test object an insulation resistance test support device for supporting test work for testing insulation resistance in a range, wherein the power conversion device is connected to a power converter main body provided in a housing and a first solar cell device. A first power cable is provided with a first plug, a first input terminal to which the first plug is connected, and a second power cable connected to the second solar cell device is provided with a second plug, a second input terminal to which a second plug is connected; a first connection conductor that connects the first input terminal and the second input terminal inside the housing of the power converter; and the first connection conductor, , a second connection conductor connected to the input side of the power converter main body; and a second connection conductor provided on the second connection conductor and connecting the first connection conductor and the input of the power converter main body at least when an insulation resistance test is performed. a switch that electrically cuts off the connection between the insulation resistance test support device and the insulation resistance test support device; A connection plug is provided, the connection plug is connected to the first input terminal, and the test terminal electrically connected to the second end of the first connection cable and the ground electrode are interposed between the ground electrode and the test terminal. 2. An insulation resistance test method including a step of applying a test voltage for an insulation resistance test of the solar cell device and the second power cable.

(5) Further, according to an insulation resistance measuring method of one aspect of the present invention, the insulation resistance of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device is tested. An insulation resistance test method by an insulation resistance test system, wherein the insulation resistance test system comprises
A power conversion device for the photovoltaic power generation system, and an insulation resistance test support device that supports a test operation of testing the insulation resistance of the test target range using an insulation resistance meter that outputs a test voltage, wherein the power conversion The device includes a power converter main body provided in a housing, a first power cable connected to a first solar cell device, a first plug provided in the first power cable, and a first input terminal to which the first plug is connected. a second power cable connected to the second solar cell device is provided with a second plug, a second input terminal to which the second plug is connected, the first input terminal, and the second input terminal; a first connection conductor that connects the inside of the housing of the power converter, a second connection conductor that connects the first connection conductor to the input side of the power converter body, and the second connection conductor. and a switch that electrically disconnects between the first connection conductor and the input side of the power converter body at least when an insulation resistance test is performed, wherein the insulation resistance test support device comprises: a terminal, wherein a first connector provided at a first end of a first connection cable is connected to the first input terminal, and electrically connected to a second end of the first connection cable ; a step of placing a test terminal at a position that allows a bird's-eye view of the insulation resistance test support device, and applying a test voltage for an insulation resistance test of the second solar cell device and the second power cable after the placement. It is an insulation resistance test method.

According to each aspect of the present invention, it is possible to provide an insulation resistance test system and an insulation resistance test method that make it possible to improve maintainability when conducting an insulation resistance test of a photovoltaic power generation system.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the photovoltaic power generation system to which the insulation resistance test assistance apparatus of embodiment is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the power converter device of embodiment. It is a block diagram of the photovoltaic power generation system 1 at the time of the insulation resistance test of embodiment. It is a lineblock diagram of photovoltaic power generation system 1 at the time of an insulation resistance test in the 1st modification of an embodiment. It is a flow chart which shows a schematic procedure of an insulation resistance test of an embodiment. It is a flow chart which shows a procedure of an insulation resistance test of an embodiment. FIG. 12 is a diagram for explaining the arrangement of the insulation resistance test support device 10 of the second modified example of the embodiment;

An embodiment of the present invention will be described below with reference to the drawings.
The solar cell device in the embodiment represents an ungrounded solar cell panel, a solar cell string, a solar cell array, and the like. "Connected" in the embodiment includes electrically connected. In the insulation resistance test of the embodiment, insulation measurement using an insulation resistance meter applied to a low-voltage distribution system (electric circuit and equipment whose power is cut off in a DC distribution system) is performed on the solar cell device and its electric circuit. It is a test applied to The switch in the embodiment may be any switch that switches between an electrically conducting state and a non-conducting state, and may be, for example, a switch having a mechanical contact or a semiconductor switch. Alternatively, the impedance may be higher than a predetermined value.

FIG. 1 is a schematic configuration diagram of a photovoltaic power generation system to which an insulation resistance test support device of an embodiment is applied. A solar power generation system 1 shown in FIG. 1 includes a solar cell device 2 and a power conversion device 3 . The illustrated solar cell device 2 includes a solar cell device 21 , a solar cell device 22 , and a solar cell device 23 . In the following description, the solar cell device 21 , the solar cell device 22 , and the solar cell device 23 are simply referred to as the solar cell device 2 when collectively described. The solar cell device 21 is an example of a first solar cell device, and the solar cell device 22 is an example of a second solar cell device.

The solar cell device 2 is connected to the power conversion device 3 by a power cable. The power conversion device 3 converts the DC power supplied from the solar cell device 2 into AC power. As described above, the photovoltaic power generation system 1 collects the DC power generated by the solar cell device 2 in the power conversion device 3 and outputs the AC power converted by the power conversion device 3 to the power system side.

For example, as shown in FIG. 3A to be described later, the solar cell device 21 is connected to the power conversion device 3 by a positive power cable L21P and a negative power cable L21N. Solar cell device 22 is similarly connected to power conversion device 3 by power cables L22P and L22N. Solar cell device 23 is similarly connected to power conversion device 3 by power cables L23P and L23N. Each of the above power cables has insulation resistance exceeding the test voltage of the insulation resistance test.

The photovoltaic power generation system 1 of the embodiment is arranged, for example, on the ground surface or on the roof of a building. In this case, the solar cell device 2 is arranged on a trestle TRE provided on the surface of the ground or the like and fixed to the trestle TRE. The power conversion device 3 is attached to a pillar, a brace, or the like of the trestle TRE. For example, the solar cell device 2 is arranged so that the light receiving surface faces upward. The height of the light-receiving surface of the solar cell device 2 becomes lower as it becomes farther from the user U in the Y-axis direction, becomes higher as it gets closer to the user U, and becomes high enough for the user U to look up on the near end side with respect to the user U. ing.

Depending on the positional relationship between the solar cell device 2 and the power conversion device 3 , the user U may need to perform work related to the power conversion device 3 under the solar cell device 2 . The photovoltaic power generation system 1 shown in the figure is an example of the above. X, Y, and Z in the drawing indicate axes of three-dimensional coordinates. It should be noted that notation of cables in the figure is partially omitted.

Drawing 2 is a figure for explaining the power converter of an embodiment. The diagram shown in FIG. 2 shows a state in which the power conversion device 3 installed in a standard manner is viewed obliquely from below.

A housing 3C of the power conversion device 3 is made of insulating resin or the like, and is independently waterproof (rainproof). 3 C of housing|casings accommodate the power converter main body in the inside.

For example, the housing 3C is formed in a substantially rectangular parallelepiped shape. The electrical connection between the solar cell device 2 and the power system is configured to be connected by a connector. Each connector is provided on one surface 3F of the housing 3C. When the power conversion device 3 is placed in a ready-to-operate state in a standard manner, the surface 3F (FIG. 1) is placed on the underside (negative direction of the Z-axis) of the housing 3C.

The surface 3F is provided with connectors CN1P, CN2P, and CN3P for positive power supply lines and connectors CN1N, CN2N, and CN3N for negative power supply lines, respectively. Connectors CN1P and CN1N, CN2P and CN2N, and CN3P and CN3N each form a pair of positive and negative electrodes.

For example, one end of the power cable L21P (first power cable) is connected to the positive electrode of the solar cell device 21 . A plug P21P (first plug) is provided at the other end of the power cable L21P. Plug P21P is connected to connector CN1P. Thereby, the positive electrode of the solar cell device 21 is connected to the connector CN1P via the power cable L21P.

One end of power cable L21N is connected to the negative electrode of solar cell device 21 . A plug P21N is provided at the other end of the power cable L21N. Plug P21N is connected to connector CN1N. Thereby, the negative electrode of the solar cell device 21 is connected to the connector CN1N through the power cable L21N. As described above, the DC power from the solar cell device 21 is supplied to the power conversion device 3 via the connector CN1P and the connector CN1N.

One end of power cable L22P (second power cable) is connected to the positive electrode of solar cell device 22 . A plug P22P (second plug) is provided at the other end of the power cable L22P. Plug P22P is connected to connector CN2P. Thereby, the positive electrode of the solar cell device 22 is connected to the connector CN2P via the power cable L22P.

One end of power cable L22N is connected to the negative electrode of solar cell device 22 . A plug P22N is provided at the other end of the power cable L22N. Plug P22N is connected to connector CN2N. Thereby, the negative electrode of the solar cell device 22 is connected to the connector CN2N through the power cable L22N. As described above, the DC power from the solar cell device 22 is supplied to the power conversion device 3 via the connectors CN2P and CN2N.

One end of power cable L23P (second power cable) is connected to the positive electrode of solar cell device 22 . A plug P23P (second plug) is provided at the other end of the power cable L23P. Plug P23P is connected to connector CN3P. Thereby, the positive electrode of the solar cell device 23 is connected to the connector CN3P via the power cable L23P.

One end of power cable L23N is connected to the negative electrode of solar cell device 23 . A plug P23N is provided at the other end of the power cable L23N. Plug P23N is connected to connector CN3N. Thereby, the negative electrode of the solar cell device 23 is connected to the connector CN3N through the power cable L23N. As described above, the DC power from the solar cell device 23 is supplied to the power conversion device 3 via the connectors CN3P and CN3N.

The state shown in the drawing shows a state in which the plug P21P provided at the end of the power cable L22P (second power cable) is removed from the connector CN1P. The positive electrode plug P21P, the plug P22P, and the plug P23P are formed in at least the same shape. The negative electrode plug P21N, the plug P22N, and the plug P23N are formed in at least the same shape. The plug P21P, the plug P22P and the plug P23P, and the plug P21N, the plug P22N and the plug P23N may have the same shape. In addition, in the power cable for positive poles and the power cable for negative poles, changing the shape of the connector is not restricted.

The connector CN1P is an example of a first input terminal, and the connector CN2P is an example of a second input terminal. As described above, each connector such as the connector CN1P is provided under the housing of the power conversion device 3 when the power conversion device 3 is arranged in an operable state.

Furthermore, the surface 3F is provided with a connector CN4 for connecting a power cable L4 for connecting the power converter 3 to the power system, and a grounding terminal ET.

FIG. 3A is a configuration diagram of the photovoltaic power generation system 1 during the insulation resistance test of the embodiment.
The photovoltaic power generation system 1 shown in FIG. 3A includes a solar cell device 2 and a power conversion device 3 as well as an insulation resistance meter 4 and an insulation resistance test support device 10 .

The power converter 3 includes at least a first connection conductor 31, a second connection conductor 32, a power converter main body 33, and a switch 34 as an electrical configuration.

The first connection conductor 31 includes a positive electrode side first connection conductor 31P and a negative electrode side first connection conductor 31N. The second connection conductor 32 includes a positive electrode side second connection conductor 32P and a negative electrode side second connection conductor 32N.

The first connection conductor 31P connects the connector CN1P, the connector CN2P, and the connector CN3P inside the housing 3C of the power conversion device 3 . The second connection conductor 32P connects the first connection conductor 31P to the positive terminal on the input side of the power converter body 33 .

The first connection conductor 31N connects the connector CN1N, the connector CN2N, and the connector CN3N inside the housing 3C of the power conversion device 3 . The second connection conductor 32N connects the first connection conductor 31N to the input side negative electrode of the power converter body 33 .

The power converter main body 33 converts the DC power supplied to the input side into AC power, and outputs the AC power to the power system via the connector CN4. The power converter main body 33 can be connected to a power system. The AC side of the power converter body 33 may be 3-phase AC with grounded neutral.

The switch 34 is an overcurrent breaker (breaker) provided on the second connection conductor 32 . The switch 34 is normally held in a conducting state. At least when the insulation resistance test is performed, the switch 34 is connected between the first connection conductor 31P and the positive terminal on the input side of the power converter main body 33 and between the first connection conductor 31N and the input side of the power converter main body 33. and the negative electrode of each are electrically cut off. By opening the switch 34 by the user's operation, the connector CN1P, the connector CN2P, the connector CN3P, the connector CN1N, the connector CN2N, the connector CN3N, and the power converter main body 33 are insulated inside the housing 3C. and the insulation resistance test can be performed.

After completing the insulation resistance test, the user U restores the switch 34 to the conductive state, thereby allowing the power conversion device 3 to perform power conversion.

The insulation resistance meter 4 outputs a test voltage at a target test point to carry out an insulation resistance test. For example, the test voltage is defined based on the voltage of the target test point relative to ground. A known insulation resistance meter can be applied to the insulation resistance meter 4 .

The insulation resistance test support device 10 includes at least a terminal 11, a test terminal 12, a circuit breaker 13, a ground side test terminal 14, a ground terminal 19, and a cable L11 (first connection cable).

The terminal 11 is connected to the power converter 3 during the insulation resistance test. For example, the terminal 11 is connected to one end of the cable L11. The other end of the cable L11 is provided with a connection plug P11 for connecting the cable L11 to the connector CN1P of the power converter 3 or the like. The fitting portion of the connection plug P11 on the connector CN1P side preferably has the same shape as the fitting portion of the plug P21P on the connector CN1P side. The insulation resistance test support device 10 is connected to the power conversion device 3 via a cable L11.

The test terminal 12 is a terminal to which an electrode of the insulation resistance meter 4 is connected. For example, the test terminal 12 may be a terminal capable of locking the electrode of the insulation resistance meter 4 . For example, the test terminals 12 are arranged on the surface of the housing 10C (support). The insulation resistance test support device 10 is formed so that the surface on which the test terminals 12 are arranged is the upper surface or the side surface of the housing 10C during the insulation resistance test. The state of the terminals 12 and the like can be viewed from above, and the test terminals 12 can be easily visually recognized even in a standing posture.

The breaker 13 is provided between the terminal 11 and the test terminal 12, and can be operated by the user to cut off or connect the electrical connection between the terminal 11 and the test terminal 12. FIG. When the user U is ready for the insulation resistance test of the solar cell device 2, the circuit breaker 13 is turned on. After finishing the insulation resistance test, the user U puts the circuit breaker 13 into the interrupting state.

The ground-side test terminal 14 is a ground electrode-side terminal that is paired with the test terminal 12 and used in an insulation resistance test using the insulation resistance meter 4 . The ground terminal 19 is connected to the ground side test terminal 14 and connects the ground side test terminal 14 to the ground. The ground terminal 19 is connected to the ground terminal ET of the power converter 3, for example. The grounding terminal ET of the power conversion device 3 is grounded under conditions suitable for the power conversion device 3 .

The insulation resistance test support device 10 may further include a terminal 15, a measurement terminal 16, a circuit breaker 17, and a cable L15.

Terminal 15 is connected to solar cell device 2 during an insulation resistance test of solar cell device 2 . One end of a cable L15 is connected to the terminal 11 . The other end of the cable L15 is provided with a connector CN15 for connecting to the plug P21P of the power cable L22P, for example. The connector CN15 may have the same shape as the connector CN1P described above. The insulation resistance test support device 10 is connected to any one of the solar cell devices 2 via a cable L15.

The measurement terminal 16 is a terminal to which the electrode of the insulation resistance meter 4 is connected, similar to the test terminal 12 . The shape of the measurement terminals 16 may be the same as that of the test terminals 12 .

The breaker 17 is provided between the terminal 15 and the measurement terminal 16, and can be operated by the user to break or connect the electrical connection between the terminal 15 and the measurement terminal 16. FIG. When the user U is ready for the insulation resistance test of the solar cell device 2, the circuit breaker 17 is turned on. After completing the insulation resistance test, the user U sets the circuit breaker 17 to the interrupting state.

An insulation resistance test using the insulation resistance test support device 10 will be described.
FIG. 4 is a flow chart showing a schematic procedure of an insulation resistance test according to the embodiment.
The user U stops the operation of the power electronics device 3 (step Sa1). The user U opens the switch 34 of the power converter 3 and the circuit breaker (not shown) to which the power converter 3 is connected (step Sa2).

Next, the user U connects the insulation resistance test support device 10 between the solar cell device 21 and the power conversion device 3 as shown in FIG. An insulation resistance test and a second insulation resistance test in which a test voltage is directly applied to solar cell device 21 are performed (step Sa3). A more detailed description of the procedure of step Sa3 will be given later.

Next, the insulation resistance meter 4 displays the result of the first insulation resistance test and the result of the second insulation resistance test (step Sa4).

Based on the result of the first insulation resistance test and the result of the second insulation resistance test, the user U determines that the insulation resistance in the test range TG on the DC side of the insulation resistance photovoltaic power generation system 1 is equal to or greater than the reference value. (Step Sa5). The above reference value is defined by the working voltage of the test target location.

Here, if an abnormality is detected in either the result of the first insulation resistance test or the result of the second insulation resistance test, the user U may It is determined that there is an abnormality in the insulation resistance (step Sa6), and the test ends.

Alternatively, if no abnormality is detected in both the result of the first insulation resistance test and the result of the second insulation resistance test, the user U may insulate the test range TG on the DC side of the photovoltaic power generation system 1. It is determined that there is no abnormality in the resistance (step Sa7), and the test is finished.

Next, a more specific insulation resistance test procedure will be described with reference to FIGS. 3A, 4, and 5. FIG. FIG. 5 is a flow chart showing the procedure of an insulation resistance test according to the embodiment.

In the photovoltaic power generation system 1, the user U performs a first insulation resistance test on the DC input side of the power conversion device 3 and a second insulation resistance test for directly testing the solar cell device 2 as a DC side insulation resistance test. Two tests of resistance testing are performed. The insulation resistance test support device 10 supports execution of these tests.

After completing step Sa1 and step Sa2 in FIG. 4 described above, the user U disconnects the cable on the positive electrode side from the power conversion device 3 and connects it to the configuration (FIG. 3A) for conducting an insulation resistance test, if necessary. change (step Sa31). For example, the plug P21P corresponding to the positive electrode of the solar cell device 21 is removed from the connector CN1P of the power conversion device 3, and the solar cell devices 22 and 23 are left connected to the power conversion device 3. As a result, the cable L<b>11 is removed from the power conversion device 3 . Furthermore, the user U connects the connection plug P11 of the cable L11 to the connector CN1P of the insulation resistance test support device 10 . The connector CN15 of the insulation resistance test support device 10 is connected to the connection plug P11 of the cable L11. This step Sa31 may be omitted if not necessary.

Next, a first insulation resistance test is performed (step Sa32). The object of the first insulation resistance test is the range connected via the test terminal 12 .

Specifically, the objects of the first insulation resistance test include both the DC input side of the power conversion device 3 and the solar cell device 2 to which the power cable is connected to the power conversion device 3 . In this state, an insulation resistance test on the DC input side of the power conversion device 3 is performed. A test voltage for an insulation resistance test can be applied to the positive electrode side of the solar cell device 23 .

Therefore, it is possible to identify the presence or absence of a failure location where the insulation resistance is lowered in the above range by one test. According to the above test method, the solar cell devices except for one of the solar cell devices 2 accommodated in the power conversion device 3 are connected in parallel by changing only one connection of the power cable. 2 can be tested together.

The result of the first insulation resistance test in step Sa32 is judged (step Sa33).

If an abnormality is detected in the result of the first insulation resistance test, it is determined that there is an abnormality in the insulation resistance within the measurement target range, and analysis is performed to individually identify the failure locations within the measurement target range. (step Sa34). As a technique for this individual analysis, a general insulation resistance test technique for each solar cell device 20 may be applied.

If no abnormality is detected in the result of the first insulation resistance test in step Sa32, the process proceeds to the next step Sa36 (step Sa35).

Next, a second insulation resistance test is performed (step Sa36). The object of the second insulation resistance test is the range connected via the measurement terminal 16 .

Specifically, the object of the second insulation resistance test includes the solar cell device 21 with one of the power cables removed from the power conversion device 3 . When the insulation resistance test of the solar cell device 21 is performed in this state, the test voltage for the insulation resistance test can be applied to the positive electrode side of the solar cell device 21 .

If an abnormality is detected in the result of the second insulation resistance test, it is determined that there is an abnormality in the insulation resistance within the measurement target range, and analysis is performed to individually identify the failure locations within the measurement target range. (step Sa38), and the process ends. As a technique for this individual analysis, a general insulation resistance test technique for each solar cell device 20 may be applied.

If no abnormality is detected in the result of the second insulation resistance test in step Sa36, the process ends (step Sa39).

As described above, it is possible to identify whether or not there is a failure location where the insulation resistance is reduced in the range on the positive electrode side of the solar cell device 21 . With the above test method, it is possible to test the positive electrode side of the solar cell device 21 that could not be tested in the first insulation resistance test.

(First modification of the embodiment)
A first modification of the embodiment will be described.
In the embodiment, the procedure for measuring the insulation resistance by applying a specified voltage to the positive electrode side is exemplified. The procedure for measuring the insulation resistance by multiplying is explained.
FIG. 3B is a configuration diagram of the photovoltaic power generation system 1 during an insulation resistance test in a modified example of the embodiment. The difference between the case of testing the negative electrode side shown in FIG. 3B and the case of testing the positive electrode side of FIG. 3A is the connection destination of the insulation resistance test support device 10 . When the positive electrode side was tested (FIG. 3A), the power cable L21P on the positive electrode side was removed from the connector CN1P of the power converter 3, and the insulation resistance test support device 10 was connected there. Alternatively, when testing the negative electrode side (FIG. 3B), for example, the negative electrode side power cable L23N is removed from the connector CN3N of the power conversion device 3, and the cable L11 of the insulation resistance test support device 10 is connected there. Connect to connector CN3N.

Similarly, the connection cable L15 of the insulation resistance test support device 10 is connected to the negative plug P23N of the solar cell device 23 instead of the solar cell device 21 .

Although the above shows the change of the connection destination, the test procedure may be performed in the same procedure as in FIG. 4 described above. In that case, the test object and the poles are different from the case shown in FIG. 1 described above. Therefore, the polarity of the test voltage should be reversed from that of the example shown in FIG. 1 so that the current during the test flows in the direction of the forward current of the solar cell device.

(Second modification of the embodiment)
As a second modification of the embodiment, the arrangement of the insulation resistance test support device 10 will be described with reference to FIG. FIG. 6 is a diagram for explaining the arrangement of the insulation resistance test support device 10 of the second modification of the embodiment.

The arrangement of the insulation resistance test support device 10 is restricted by the length of the cable L11. The shape of the housing 3C of the power converter 3 is approximated to a rectangular parallelepiped, and the length of the cable L11 is preferably longer than the shortest side of the rectangular parallelepiped.

FIG. 6A illustrates a case where the cable L11 is relatively short.
For example, assume that the housing 3C is approximated to a rectangular parallelepiped in an installed state, and that the depth direction (positive direction of the Y-axis) of the rectangular parallelepiped is the shortest side among the sides. As an example of a more specific length, assume it is on the order of 10 centimeters. This numerical value is merely an example, and may be defined based on the size of the housing 3C.

If the length of the cable L11 is the same as the above depth, the insulation resistance test support device 10 should be positioned directly below the surface 3F corresponding to the lower part of the housing 3C by the same length as the above depth. become. Even in this state, if the user U stands at an appropriate distance from the front of the housing 3C, the user U can visually recognize the insulation resistance test support device 10 without taking a stooped posture. In the above description, the front of the housing 3C is the surface facing the user U, for example.

Actually, as shown in FIG. 6(b), a plurality of power cables are connected to the housing 3C, and the insulation resistance test support device is located closer to the user side (in the negative Y-axis direction) than these power cables. Since the device 10 can be arranged, the visibility of the insulation resistance test support device 10 is further enhanced.

The above example simply illustrates the case where the cable L11 is hung from the bottom of the housing 3C. Since the insulation resistance test support device 10 can be placed at a position higher than the height of 3F, it is preferable to set the length of the cable L11 to a suitable length in consideration of workability and safety. For example, by setting the length of the cable L11 so that the user U can arrange the insulation resistance tester 4 and the insulation resistance test support device 10 at hand, the user U can work without taking an unreasonable working posture. It is possible to improve workability.

Note that the arrangement of the solar cell device 2 and the power conversion device 3 in the photovoltaic power generation system 1 shown in FIG. etc., or the power converter 3 may be arranged on the wall of a building or the like.

According to the above-described embodiment, the insulation resistance test support device 10 is a test target range of the photovoltaic power generation system 1 including the ungrounded solar cell device 2 and the power conversion device 3 connected to the solar cell device. applied to the insulation resistance test of For the test target range of the photovoltaic power generation system 1, when testing the insulation resistance of the test target range using the insulation resistance meter 4 that outputs the test voltage, the insulation resistance test support device 10 performs the test work related to the insulation resistance test. to support

The insulation resistance test support device 10 includes at least a cable L<b>11 , a terminal 11 and a test terminal 12 . A connection plug P1P that can be fitted to a connector CN1P of the power conversion device 3 is provided at a first end of the cable L11 that connects to the power conversion device 3 . A second end of the cable L11 is electrically connected to the terminal 11 . The insulation resistance meter 4 and the terminal 11 are connected to the test terminal 12 . The test terminal 12 can apply the test voltage for the insulation resistance test of the solar cell device 22 and the power cable L22P to the connector CN1P via the terminal 11. FIG. The insulation resistance test support device 10 is arranged between the insulation resistance meter 4 and the test target range, so that the test voltage output from the insulation resistance tester 4 can be applied to the circuit in the test target range. It becomes possible to improve maintainability when performing an insulation resistance test of a power generation system.

Further, the connector CN1P is provided on the surface 3F corresponding to the lower portion of the housing 3C of the power converter 3 when the power converter 3 is placed in an operable state, and is connected with the connection plug P1P. If the shape of the housing 3C of the power converter 3 is approximated to a rectangular parallelepiped, the length of the first connection cable L11 should be longer than the shortest side of the rectangular parallelepiped. As a result, the insulation resistance test support device 1 can be arranged at a position where the test can be easily performed.

Further, the insulation resistance test support device 1 may further include a box-shaped housing 10C (support). In this case, the test terminals 12 and the test terminals 15 are preferably arranged on the top surface or side surface of the housing 10C in a state where the connection plug P1P is connected to the connector CN1P.

Further, as described above, the insulation resistance test support apparatus 10 provides the cable L11 with the connection plug P1P that can be fitted to the connector CN1P of the power conversion device 3, so that the connector CN1P of the power conversion device 3 is It is no longer necessary to hold the tester bar to be applied and the cable to which the tester bar is connected, and the test is not performed in a stooped posture.

Further, by connecting the cable L21P removed from the connector CN1P of the power conversion device 3 to the cable L15 connected to the insulation resistance test support device 10, the end of the cable L21P (plug P21P) is prevented from falling to the ground. can be prevented, and the trouble of taking care to prevent contamination during the test can be reduced.

The insulation resistance test support device 10 includes a circuit breaker 13 and a circuit breaker 17. Even if the solar cell device 2 installed outdoors is in a power generation state and a potential difference is generated between the cables L21P and L21N, Since the test terminal 12 and the measurement terminal 16 can be connected with no voltage applied to the insulation resistance meter 4, the safety during the work can be improved and the risk of electric shock can be reduced.

Even when the type of the power converter 3 and the shape of the connector CN1P are different, the cable L11 and the cable L15 provided in the insulation resistance test support device 10 can be easily exchanged.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

In the insulation resistance test, a single power cable is removed from the power conversion device 3. However, without being limited to this, a pair of positive and negative electrodes of the solar cell device 2 can be used instead. The insulation resistance test may be performed with the power cable removed.

DESCRIPTION OF SYMBOLS 1... Solar power generation system, 2... Solar cell apparatus, 3... Power converter, 31... First connection conductor, 32... Second connection conductor, 33... Power converter main body, 34... Switch, 4... Insulation resistance meter, DESCRIPTION OF SYMBOLS 10... Insulation resistance test support apparatus 11... Terminal 12... Test terminal 13... Circuit breaker 14... Ground side test terminal 15... Terminal 16... Measurement terminal 17... Circuit breaker 19... Ground terminal L11... Cable (first connection cable), L15... Cable (second connection cable)

Claims (5)

An insulation resistance test system for performing an insulation resistance test on a test target range of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device,
a power conversion device for the photovoltaic power generation system;
an insulation resistance test support device that supports a test operation of testing the insulation resistance of the test target range using an insulation resistance meter that outputs a test voltage ;
with
The power converter,
a power converter main body provided in a housing;
A first power cable connected to the first solar cell device is provided with a first plug, and a first input terminal to which the first plug is connected;
a second power cable connected to the second solar cell device is provided with a second plug, and a second input terminal to which the second plug is connected;
a first connection conductor that connects the first input terminal and the second input terminal inside the housing of the power converter;
a second connection conductor that connects the first connection conductor to the input side of the power converter body;
a switch provided on the second connection conductor for electrically disconnecting between the first connection conductor and the input side of the power converter main body at least when an insulation resistance test is performed;
with
The insulation resistance test support device is
a first connection cable having a connection plug that can be fitted to the first input terminal at a first end;
a terminal to which the second end of the first connection cable is electrically connected;
a test terminal connected to the insulation resistance meter and the terminal and capable of applying a test voltage for an insulation resistance test of the second solar cell device and the second power cable to the first input terminal via the terminal; ,
with
The insulation resistance test support device is
An insulation resistance test system arranged between the insulation resistance meter and the test object range. The first input terminal is provided at a lower portion of a housing of the power conversion device when the power conversion device is placed in an operable state, and is connected to the connection plug,
When the shape of the housing of the power conversion device is approximated to a rectangular parallelepiped, the length of the first connection cable is longer than the length of the shortest side of the sides of the rectangular parallelepiped,
The insulation resistance test system of claim 1. further comprising a box-shaped support;
The test terminal is
arranged on the upper or side surface of the support in a state where the connection plug is connected to the first input terminal;
The insulation resistance test system of claim 1. An insulation resistance test method using an insulation resistance test system for testing insulation resistance in a test target range of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device, ,
The insulation resistance test system includes:
a power conversion device for the photovoltaic power generation system;
an insulation resistance test support device that supports a test operation of testing the insulation resistance of the test target range using an insulation resistance meter that outputs a test voltage;
with
The power converter,
a power converter main body provided in a housing;
A first power cable connected to the first solar cell device is provided with a first plug, and a first input terminal to which the first plug is connected;
a second power cable connected to the second solar cell device is provided with a second plug, and a second input terminal to which the second plug is connected;
a first connection conductor that connects the first input terminal and the second input terminal inside the housing of the power converter;
a second connection conductor that connects the first connection conductor to the input side of the power converter body;
a switch provided on the second connection conductor for electrically disconnecting between the first connection conductor and the input side of the power converter main body at least when an insulation resistance test is performed;
with
The insulation resistance test support device includes a test terminal,
A connection plug that can be fitted to the first input terminal is provided at a first end of the first connection cable, and the connection plug is connected to the first input terminal,
A test voltage for an insulation resistance test of the second solar cell device and the second power cable is applied between the test terminal electrically connected to the second end of the first connection cable and a ground electrode. process,
Insulation resistance test method including. An insulation resistance test method using an insulation resistance test system for testing the insulation resistance of a photovoltaic power generation system including an ungrounded solar cell device and a power conversion device connected to the solar cell device,
The insulation resistance test system includes:
a power conversion device for the photovoltaic power generation system;
an insulation resistance test support device that supports a test operation of testing the insulation resistance of the test target range using an insulation resistance meter that outputs a test voltage;
with
The power converter,
a power converter main body provided in a housing;
A first power cable connected to the first solar cell device is provided with a first plug, and a first input terminal to which the first plug is connected;
a second power cable connected to the second solar cell device is provided with a second plug, and a second input terminal to which the second plug is connected;
a first connection conductor that connects the first input terminal and the second input terminal inside the housing of the power converter;
a second connection conductor that connects the first connection conductor to the input side of the power converter body;
a switch provided on the second connection conductor for electrically disconnecting between the first connection conductor and the input side of the power converter main body at least when an insulation resistance test is performed;
with
The insulation resistance test support device includes a test terminal,
connecting a first connector provided at a first end of a first connection cable to the first input terminal;
arranging the test terminal electrically connected to the second end of the first connection cable at a position where the insulation resistance test support device can be overlooked,
a step of applying a test voltage for an insulation resistance test of the second solar cell device and the second power cable after the arrangement;
Insulation resistance test method including.

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