JP2016058254A - Terminal block and power device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the terminal block of a power device in which continuous heat generation can be prevented by shutting off the power, when heat is generated in a state where a terminal screw is loose, and can be restored without requiring any repair.SOLUTION: A terminal block 10 has a primary terminal fastening part 2a connected with the primary wiring, a secondary terminal fastening part 2b connected with the secondary wiring, a conductive plate 4 attached to the terminal block body 1, and connecting the primary terminal fastening part 2a and secondary terminal fastening part 2b, and PTC thermistors 6a-6e for detecting the temperature of the conductive plate 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a terminal block and a power device, and more particularly to detection of abnormal heat generation.

  In power converters used in power generators such as solar power generation facilities, when using external wiring that is electric wires from the outside for electrical equipment used indoors and outdoors, the internal wiring inside the equipment and the external A terminal block for relaying the external wiring from the terminal is provided. The terminal block is formed by attaching a metal terminal fitting to a resin block for connecting external wiring, and the terminal fitting is connected to the conductive portion of the terminal block by a terminal screw.

  Connection of external wiring to the terminal block of these electrical equipment is performed on site at the time of installation of the electrical equipment, but there is a looseness due to insufficient fastening at the fastening portion between the electric wire and the terminal fitting constituting the external wiring, or When loosening occurs due to secular change, the contact resistance increases at the fastening portion. In other words, if a current flows with the terminal screw loosened, the resistance between the electric wire and the terminal fitting will increase, and a spark will fly or heat will be generated. If the heat generation state as described above continues for a long time, the resin block may be deformed to cause fire or smoke.

  Therefore, for example, in Patent Document 1, in order to avoid ignition or smoke generation due to abnormal heat generation due to loosening of the terminal fastening portion of the terminal block, a configuration in which a temperature fuse that blows when reaching a set temperature is embedded in a resin block, It is disclosed. According to the configuration of Patent Document 1, when the resistance between the electric wire and the terminal fitting increases and the resin block generates heat, the thermal fuse is blown to prevent energization and prevent the heat generation state from continuing. doing.

JP 2002-343459 A

  However, according to the above-described conventional terminal block, it is possible to prevent the heat generation state from continuing due to the melting of the thermal fuse, but the thermal fuse once blown cannot be reused. Therefore, in order to restore the operation of the solar power generation facility, there is a problem that repair by an engineer is required and it takes time and effort to restore.

  Also, heat generated when the terminal screw is loose is likely to occur in a device in which a large current flows through the terminal block. The temperature inside the device rises due to the flow of a large current, but the temperature rise due to the flow of a large current is not a malfunction of the device. There is a need. For this reason, there is a problem that it is difficult to select a set temperature of the thermal fuse. For example, if the set temperature of the thermal fuse is too high, the terminal block or wiring is likely to be damaged due to the continued heat generation, and if the set temperature of the thermal fuse is too low, the thermal fuse may be blown out even though it is not an equipment malfunction. Operation is likely to occur.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a terminal block that can improve the accuracy of detection of heat generation due to loosening of a terminal screw and facilitate restoration work.

  In order to solve the above-described problems and achieve the object, the present invention provides a terminal having a primary side terminal fastening portion to which a primary side wiring is connected and a secondary side terminal fastening portion to which a secondary side wiring is connected. It has a base body, a conductive plate that is attached to the terminal base body and connects the primary side terminal fastening portion and the secondary side terminal fastening portion, and a PTC thermistor that detects the temperature of the terminal base or the conductive plate. .

  According to the present invention, it is possible to improve the detection accuracy of heat generation due to the looseness of the terminal screw with a simple structure, and to facilitate the restoration work.

The perspective view which shows the terminal block concerning Embodiment 1 of this invention. It is a figure which shows the terminal block concerning Embodiment 1 of this invention, (a) is a top view of the terminal block, (b) is AA sectional drawing of (a). It is a principal part enlarged explanatory view which shows the terminal fastening part in the terminal block of Embodiment 1, (a) is a figure which shows a volt | bolt and a nut, (b) is explanatory drawing which shows a fastening state. Wiring diagram inside the PTC thermistor and the power converter The figure which shows the solar energy power generation system provided with the electric power apparatus using the terminal block concerning Embodiment 1 of this invention. Explanatory diagram showing the temperature-resistance characteristic of the PTC thermistor Explanatory drawing which shows each characteristic of temperature-resistance value at the time of providing a plurality of PTC thermistors The perspective view which shows the terminal block concerning Embodiment 2 of this invention. It is a figure which shows the terminal block concerning Embodiment 2 of this invention, (a) is a top view of the terminal block, (b) is BB sectional drawing of (a).

  Hereinafter, a terminal block and a power device according to an embodiment of the present invention will be described in detail with reference to the drawings. The invention is not limited to the embodiments. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings. Furthermore, the cross section may not be hatched for easy viewing.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a terminal block according to a first embodiment of the present invention. FIG. 2A is a top view of the terminal block, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. The terminal block 10 according to the first embodiment detects heat generation when the terminal screw of the primary side terminal fastening portion 2a or the secondary side terminal fastening portion 2b, which may cause abnormal heat generation due to loosening of the terminal screw, is loosened. The PTC thermistors 6a to 6e, which are heat sensitive elements, are used. The PTC thermistors 6a to 6e used in the present embodiment are composed of discrete resistance elements using barium titanate designed by adjusting the composition so as to have independent Curie points. When the PTC thermistor mainly composed of barium titanate exceeds the Curie point, the crystal system undergoes a phase transition from the tetragonal system to the cubic system. Due to the phase transition of barium titanate, the electric resistance is rapidly increased when the Curie point is exceeded, and the current is cut off when the temperature exceeds a certain temperature. FIG. 2B corresponds to the AA cross section of FIG.

  The terminal block 10 according to the first embodiment is connected to a terminal block body 1 made of a resin molded body, a primary terminal fastening portion 2a to which a primary wiring of the terminal block main body 1 is connected, and a secondary wiring. PTC provided corresponding to each of the conductive plate 4, the conductive plate 4 connecting the secondary side terminal fastening portion 2 b, the primary side terminal fastening portion 2 a and the secondary side terminal fastening portion 2 b, the temperature detection substrate 5 And thermistors 6a to 6e. The PTC thermistor is mounted on the temperature detection substrate 5. The temperature detection substrate 5 is arranged perpendicular to the extending direction of the conductive plate 4 between the primary side and secondary side terminal fastening portions 2a, 2b. Further, the PTC thermistor forming surface of the temperature detection substrate 5 is perpendicular to the surface of the conductive plate 4.

The terminal block 10 is provided inside a power converter 200 described later. Connected to the terminal block 10 is a primary side wiring portion 3a which is an external wiring of the DC input and AC output of the power converter 200. In FIG. 2A, the two terminals on the right side correspond to a DC input terminal to which DC power from the solar cell module 100 is input, and the three terminals on the left side correspond to an AC output terminal that supplies AC power to the load 400 and the like. Accordingly, the power flowing through the wiring portion at each position is different, and there is a difference in the amount of heat generated due to the looseness of the terminal screw at the terminal fastening portion. Therefore, in the present embodiment, the PTC thermistors 6d and 6e arranged at the positions corresponding to the right two terminals are more curie than the PTC thermistors 6a, 6b and 6c arranged at the positions corresponding to the left three terminals. _Tc is set to be low. Further, among the PTC thermistors 6a, 6b, and 6c, the center 6b is affected by the temperature rise of the other AC output terminals and becomes the highest temperature, so that the Curie point T _c is higher than that of 6a and 6c. Is set higher. Further, the secondary side wiring portion 3b which is an internal wiring to be connected to the device in the power converter 200 is also connected to the terminal block 10 in the same manner.

  In the terminal block 10, the conductive plate 4 is attached to the terminal block main body 1, and the secondary side wiring portion 3 b and the primary side wiring portion 3 a are electrically connected by the conductive plate 4. The conductive plate 4 is attached with a primary side terminal fastening portion 2a and a secondary side terminal fastening portion 2b each having a terminal screw on one side and the other side. By fastening the terminal screw, the primary side wiring part 3 a and the secondary side wiring part 3 b are fixed to the conductive plate 4. Thereby, the electrically conductive plate 4 and the primary side wiring part 3a and the secondary side wiring part 3b are electrically connected.

  A temperature detection substrate 5 that is a printed wiring board is attached to the central portion of the terminal block body 1 made of a resin molded body, and five PTC thermistors 6 a to 6 e are attached to the temperature detection substrate 5. As shown in FIGS. 2A and 2B, the PTC thermistors 6a to 6e are connected to the conductive plate installation region C where the conductive plate 4 is installed in a plan view, that is, primary terminal fastening provided with terminal screws. It is attached in the middle of the part 2a and the secondary side terminal fastening part 2b.

  In the primary side terminal fastening portion 2a, the primary side crimp terminal 30a and the conductive plate 4 are fastened by a bolt 20 that is a terminal screw. The primary side crimp terminal 30a is connected to the primary side wiring member 32a by crimping via the crimping tube 31a. On the other hand, in the secondary side terminal fastening portion 2b, the secondary side crimp terminal 30b and the conductive plate 4 are fastened by a bolt 20 that is a terminal screw. The secondary side crimping terminal 30b is connected to the secondary side wiring member 32b by crimping via the crimping tube 31b. Here, the primary side wiring portion 3a includes a primary side crimp terminal 30a and a primary side wiring member 32a, and the secondary side wiring portion 3b includes a secondary side crimp terminal 30b and a secondary side wiring member 32b. The primary wiring part 3a and the secondary wiring part 3b are connected via the conductive plate 4. A crimping tube 31a is formed between the primary side crimping terminal 30a and the primary side wiring member 32a, and a crimping tube 31b is formed between the secondary side crimping terminal 30b and the secondary side wiring member 32b. Yes. Hereinafter, the primary side crimp terminal 30a and the secondary side crimp terminal 30b are collectively referred to as a crimp terminal 30.

  In the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b in the present embodiment, the terminal fastening is performed by screwing the bolt 20 constituting the terminal screw and the bolt 20 shown in FIG. With the mating nut 22. The bolt 20 includes a bolt head 20a and a bolt main body portion 20b having a smaller diameter than the bolt head 20a, and a screw thread 20N is formed on the bolt main body portion 20b. Fastening is achieved by screwing a screw groove 22N to be screwed into the screw thread 20N of the bolt main body portion 20b with a nut 22 formed therein. FIG. 3B is a diagram showing the side surface in the fastened state, but in order to facilitate understanding, the nut 22 is described so that the screw groove 22N on the inner surface can be seen. In the present embodiment, the nut 22 is fitted into the recess 1c formed in the terminal block body 1, and the crimp terminal 30 and the washer 21 formed at the tip of the conductive plate 4, the primary side wiring part 3a or the secondary side wiring part 3b. The bolt 20 through which is inserted is screwed into the nut 22 and fixed. By screwing the screw thread 20N of the bolt 20 into the screw groove 22N of the nut 22, terminal fastening is performed at the primary terminal fastening portion 2a and the secondary terminal fastening portion 2b, respectively. Here, the crimp terminal 30 is formed at the front end of the primary side wiring portion 3a or the secondary side wiring portion 3b, and has an insertion hole for allowing fastening by inserting through the bolt main body portion 20b and interfering with the bolt head 20a. Have. The conductive plate 4 is a plate-like body that connects the primary side terminal and the secondary side terminal, but has an insertion hole for inserting the bolt main body portion 20b, and the bolt 20 and the nut 22 are fastened. Thus, the primary side terminal and the secondary side terminal are connected.

  The PTC thermistors 6a to 6e are provided on the primary surface 5A of the temperature detection substrate 5, but may be mounted on either the primary surface 5A or the secondary surface 5B, or on both surfaces. May be. By arranging the PTC thermistors independently on both surfaces of the temperature detection substrate 5, it is possible to detect the temperature rise of the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b with high accuracy. In this case, by using a substrate having low thermal conductivity as the temperature detection substrate 5, temperature rise on the primary side terminal fastening portion 2a side and secondary side terminal fastening portion 2b side is detected not by thermal conduction but by thermal radiation. It is possible to detect a temperature rise with higher accuracy. Furthermore, the temperature rise on either side of the primary-side terminal fastening portion 2a or the secondary-side terminal fastening portion 2b by separately connecting circuits for temperature detection on both surfaces of the temperature detection substrate 5 Can be determined. On the other hand, by using a substrate having high thermal conductivity as the temperature detection substrate 5, the temperature rise on the primary terminal fastening portion 2a side and the secondary terminal fastening portion 2b side is detected by transmitting both heat conduction and heat radiation. It is possible to detect the temperature rise at a higher speed. In this case, it is difficult to identify which side or which terminal the temperature rises, but since it can be detected at high speed, it can be used according to the application. In addition, the PTC thermistors 6a to 6e may have the sensor chip constituting the PTC thermistor mounted on the temperature detection substrate 5, but may be directly formed on the substrate by a thick film circuit or a thin film circuit. When a circuit is directly formed on a substrate, the Curie point can be adjusted by the material composition, width, length, film thickness, etc. of the resistance pattern constituting the thermistor. Therefore, when a PTC thermistor having a different Curie point is used, it is easier to form the circuit by forming a circuit directly on the substrate.

  In the terminal block according to the present embodiment, as shown in FIG. 3B, the nut 22 is fitted in the recess 1c formed in the terminal block body 1 in the primary terminal fastening portion 2a and the secondary terminal fastening portion 2b. The conductive plate 4 is mounted on the nut 22 such that the screw hole portion of the nut 22 and the insertion hole of the conductive plate 4 overlap. When connecting the wiring, the insertion hole of the crimp terminal 30 formed at the front end of the primary side wiring part 3a or the secondary side wiring part 3b is overlaid on the insertion hole of the conductive plate 4, and the washer 21 is applied after the overlapping. The bolt 20 is inserted. Then, the screw thread 20N of the bolt 20 is screwed into the screw groove 22N of the nut 22 and fixed. By screwing the screw thread 20N of the bolt 20 into the screw groove 22N of the nut 22, terminal fastening is performed at the primary terminal fastening portion 2a and the secondary terminal fastening portion 2b, respectively. In the present embodiment, terminal fastening is performed at a total of 10 locations, that is, 5 locations at the primary side terminal fastening portion 2a and 5 locations at the secondary side terminal fastening portion 2b.

  FIG. 4 is a wiring diagram inside the temperature detection substrate 5 and the power converter 200 to which the PTC thermistors 6a to 6e are attached. The plurality of PTC thermistors 6 a to 6 e are connected in series, and the whole PTC thermistors 6 a to 6 e constitute one circuit and are connected to the connector 7 on the temperature detection substrate 5. The connector 7 on the temperature detection board 5 is connected to the control board connector 27 and is connected to the control circuit 23 of the power converter 200.

  With the above configuration, in the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b, the temperature detection substrate 5 on which the PTC thermistors 6a to 6e are mounted is mounted on the terminal block 10 so that the PTC thermistors 6a to 6e are provided. The abnormal heat generation detection can be ensured. The PTC thermistors 6a to 6e are formed so as to have different Curie points, and have independent set temperatures.

  As shown in FIGS. 1 and 2A, the temperature detection substrate 5 has a connector 7 that forms a connection portion with another substrate at the end. The connector 7 is connected to a signal line (not shown), and constitutes a signal line connection unit for sending a temperature signal detected by the PTC thermistors 6a to 6e to a control unit equipped with a processing circuit such as a control board. A control board (not shown) receives the temperature signal, determines whether or not the temperature is to be warned, and if it is equal to or higher than the temperature to be warned, performs a measure such as stopping operation and issuing a warning. Therefore, abnormality of the terminal portion can be detected at an early stage by the PTC thermistors 6a to 6e having independent set temperatures. If an abnormality is detected in any one of the PTC thermistors 6a to 6e, a temperature signal is transmitted to the control circuit 23 via the connector 7 and the control board connector 27. When the temperature signal detected by the PTC thermistors 6a to 6e is transmitted to the control circuit via the connector 7 and an abnormal signal is transmitted from the control circuit 23, the circuit cutoff state is maintained. On the other hand, when the abnormality release signal is transmitted, the PTC thermistors 6a to 6e can be immediately recovered to return the circuit to the normal state.

  FIG. 5: is a block diagram which shows schematic structure of the solar energy power generation system provided with the terminal block concerning Embodiment 1 of this invention. In the solar power generation system, DC power generated by the solar cell module 100 is converted into AC power by the power converter 200. The power converter 200 is a power device called a power conditioner. The AC power converted by the power converter 200 is supplied to the AC power supply 400 or the load 500 via the distribution board 300 using a grid interconnection technique. Here, when the generated power generated by the solar cell module 100 is less than the power of the load 500, the insufficient power is supplied from the AC power source 400, which is a commercial power source, to the load 500, and the generated power is higher than the power of the load 500. When there are many, surplus electric power is supplied to AC power supply 400 which is a commercial power supply. In addition, the capacity | capacitance of the power converter for homes currently marketed has many things of about 2kW-6kW.

  The solar cell module 100 is formed by connecting a plurality of solar cells in series so as to obtain a constant power generation output. In the case of a house, the number of solar cell modules 100 corresponding to the power to be generated is arranged on the roof of the house. The power converter 200 and the distribution board 300 are respectively arranged at appropriate positions such as a house wall and a house.

  In the solar power generation system, the DC power generated by the solar battery module 100 including a plurality of solar cells connected in series is input in parallel for a number of parallel currents and collected into one generated power, which is a power conditioner. Output to the converter 200. The power converter 200 converts the input DC power into AC power. The power converter 200 outputs AC power and supplies the AC power to the load 500 and the AC power source 400 via the distribution board 300.

  The power converter 200 constituting the power distribution device of the present embodiment is connected to the input unit connected to the solar cell module 100, the power conversion unit that converts the DC power input to the input unit, and the power conversion unit. The output filter, the interconnection switch, the output unit connected to the load 500, a control circuit for controlling the power conversion unit, and a notification unit are provided. In addition, the input part and output part in the power converter 200 are equivalent to the terminal block concerning this Embodiment, and are attached to the terminal block main body 1 as the primary side terminal fastening part 2a. The power converter 200 and the output filter are connected by the secondary terminal fastening portion 2b that is an internal wiring. That is, the temperature rise of the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b is crossed over the conductive plate 4 connecting the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b. It is assumed that the substrate 5 is arranged vertically and has a temperature detection substrate 5. A PTC thermistor for detecting abnormal heat generation is mounted on the temperature detection substrate 5.

  The DC output power of the solar cell module 100 is input to the input unit of the power converter 200 via the connection box.

  The power conversion unit of the power converter 200 is formed by a converter, an inverter, and an output filter, and the converted output output from the output filter is output to the output unit via the interconnection switch. The converter has a DC (Direct Current) / DC conversion function for converting DC power applied to the input unit into DC power of another voltage value. The inverter is composed of semiconductor switching elements and diodes such as FET (Field Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor) and converts the DC power input from the converter into AC power by the switching operation of the semiconductor switching element or diode. To do. The output filter is composed of a combination of a reactor and a capacitor, and shapes the pulsed AC waveform output from the inverter into a sinusoidal AC waveform.

  An AC power source 400 is connected to the output unit of the power converter 200 via the distribution board 300. A part of the output of the power converter is supplied to the load 500.

  The control circuit is controlled by DC / DC conversion operation by turning on and off the switching elements of the converter by program control, DC / AC conversion operation by generating switching operation command by PWM (Pulse Width Modulation) control by the inverter, and open / close operation And open / close control of the container. The interconnection switch is provided to open the connection with the AC power supply 400 and open the inverter from the AC power supply 400, for example, when the AC power supply 400 fails.

  The load 500 is a home appliance such as a lighting fixture, a refrigerator, a washing machine, or a vacuum cleaner, or an external appliance such as a motor. In the solar power generation system, when surplus power is not consumed by the load 500 and surplus power is generated, the surplus power is reversely flowed to the AC power source 400.

  Next, installation work for a solar power generation system in a house will be described. First, the required number of solar cell modules 100 are installed on the roof, and the tip of the output cable is connected to the input section of a connection box (not shown) installed under the house eaves or in the house for each predetermined number of serial modules. . The junction box has a current collecting function for outputting a plurality of inputs as one output. Since the output part of the connection box is composed of a positive electrode side output terminal and a negative electrode side output terminal, one end of the pair cable between the positive electrode side and the negative electrode side is connected to the output part of the connection box. And the other end of a pair cable is drawn in in the house where the power converter 200 is arrange | positioned, and it connects to the terminal block provided in the input part of the power converter 200 which comprises a power distribution apparatus.

Next, the operation of the terminal block according to the first embodiment will be described with reference to FIGS. FIG. 6 is a diagram showing characteristics of the PTC thermistor. 6 and 7, the horizontal axis indicates the temperature of the PTC thermistor, and the vertical axis indicates the resistance value of the PTC thermistor. The PTC thermistor has a characteristic that the resistance value increases abruptly when the Curie point _Tc is reached. The Curie point varies depending on the physical properties, and the resistance value changes by several tens of times or more of the normal temperature T ₀ due to temperature change. Further, the Curie point _Tc can be accurately manufactured according to the design value by adjusting the additive at the time of manufacturing the PTC thermistor.

  In the present embodiment, the temperature when the bolt 20 that is the terminal screw of the terminal block is loosened varies depending on the position of the bolt 20. That is, since the amount of heat generated varies depending on the power flowing through the wiring that is fastened to the position, the temperature to be detected is determined in accordance with the temperature rise due to the amount of heat generated when the bolt 20 is loosened at each installation position of the bolt 20. . The Curie point temperatures of the thermistors 6a to 6e are set so as to be the determined detection temperature. For example, the bolt 20 fastened to the conductive plate 4 in contact with the position where the PTC thermistor 6b is installed on the temperature detection substrate 5 has the highest temperature when the bolt 20 is loosened. Therefore, the characteristics of the PTC thermistor 6b are: One having the characteristics of the PTC thermistor 6b shown in FIG. 7 is selected. Further, since the bolt 20 fastened to the conductive plate 4 in contact with the PTC thermistor 6d installation position of the temperature detection substrate 5 has the lowest temperature when the bolt 20 is loosened, the characteristics of the PTC thermistor 6d are 7 having the characteristics of the PTC thermistor 6d shown in FIG.

As described above, when the PTC thermistor is appropriately selected and configured, when the bolt 20 is not loosened, all the PTC thermistors have a temperature equal to or lower than the Curie point. combined resistance of the circuit constituted by five PTC thermistors 6a~6e, when the resistance value of the ambient temperature of the PTC thermistor 6a~6e and R ₀ is 5 times the value of R _0. However, for example, when loosening occurs in the bolt 20 fastened to the conductive plate 4 in contact with the position where the PTC thermistor 6b is installed on the temperature detection substrate 5, the bolt 20 generates heat and the temperature rises. As a result, the temperature of the PTC thermistor 6b also rises, and when the temperature becomes equal to or higher than the Curie point _Tc of the PTC thermistor 6b, the resistance value of the PTC thermistor 6b becomes several tens of times the value of _R0 . That is, the resistance value when the PTC thermistor 6b becomes equal to or higher than the Curie point _Tc is sufficiently large so that the resistance value _R0 at room temperature can be ignored. Therefore, the combined resistance of the circuit composed of five PTC thermistors is substantially equal to the resistance value of the PTC thermistor 6b. For this reason, any one of the PTC thermistors 6a to 6e is curieized by monitoring whether or not the combined resistance of the circuit constituted by the five PTC thermistors 6a to 6e is equal to or higher than the resistance value of the temperature at the Curie point. It is possible to easily determine whether or not the score has been exceeded. In other words, with the above configuration, it is possible to accurately determine that the bolts 6a to 6e are loosened and the temperature has risen with a simple configuration.

  In addition, the temperature at the Curie point of each PTC thermistor 6a to 6e is accurately selected according to the temperature when the bolt 20 of each terminal fastening portion is loosened, thereby accurately detecting that the bolt 20 has been loosened. can do. In the present embodiment, the PTC thermistor corresponding to each of the bolts 20 is attached. For example, even if a structure in which one PTC thermistor is provided for a plurality of bolts, a slight decrease in accuracy is avoided. Although not obtained, the same effect can be expected.

  In the present embodiment, as described above, the temperature of the Curie point of each PTC thermistor 6a to 6e is determined by the power value of the circuit connected at the terminal fastening portion, and the bolt that is the terminal screw is loosened. Appropriately selected according to the temperature that can rise when it occurs. However, within the allowable range, the temperature of the Curie point of the PTC thermistor can be unified to the same temperature. Thereby, mounting | wearing becomes easy.

  As described above, when the terminal screw is loosened and the temperature of any of the PTC thermistors is equal to or higher than the Curie point, the combined resistance of the circuit composed of the five PTC thermistors greatly changes, The value is several tens of times larger than the resistance value. When the combined resistance becomes a value that is several tens of times larger than the resistance value at room temperature, the control circuit 23 that has received the output from the temperature detection substrate 5 performs the operation of the power conversion unit of the power converter 200. Stop or release the linkage switch and make a decision to stop the operation. As a result, the current is interrupted before the terminal block 10 or the wiring is damaged, and the heat generation state can be prevented from continuing. As described above, by monitoring the combined resistance of the circuit formed by the PTC thermistor, it is possible to monitor the temperature rise caused by the looseness of the terminal screw. Therefore, it is possible to improve the accuracy of the determination to cut off the power supply with a simple structure.

  When the abnormality detection as described above is performed, the control circuit 23 transmits an abnormality signal in order to quickly notify the user of the abnormality. Based on the reception of the abnormal signal, an alarm is issued using information expression such as visual information by an LED (not shown) or auditory information by an alarm sound. The alarm device or LED that issues an alarm may be provided in a building where the photovoltaic power generation system is installed or in the power converter 200 itself.

  Further, the control circuit 23 restores the supply of power when a reset operation is performed. The reset operation is a re-operation of a power switch (not shown) of the power converter 200, for example. When performing the reset operation, the power switch of the power converter 200 becomes a reset operation means for performing the reset operation. Note that the reset operation means may be provided independently of the power switch of the power converter 200 and may be provided at another place in the room of the building where the solar power generation system is installed. Further, temperature information such as temperature difference information for determining a temperature abnormality is stored in a storage unit (not shown) provided in the power converter 200. Further, the storage unit and the control circuit 23 may be provided on the terminal block. Since power supply can be restored only by a reset operation, troublesome work such as fuse replacement can be omitted, and the restoration work can be facilitated.

  When contact failure of the connector 7 occurs, the contact resistance value of the connector 7 greatly increases, so that the terminal screw is loosened, and the temperature of any of the PTC thermistors 6a to 6e becomes equal to or higher than the Curie point. It becomes the same state. Therefore, even in the case of a failure in the connector portion, the control circuit 23 cuts off the power supply from the power converter 200 to the load or the like, so that an extremely safe configuration can be realized.

  With the configuration described above, according to the power device of the present embodiment, the PTC thermistors 6a to 6e are detected by the connector 7 that is provided at the end of the temperature detection substrate 5 and that forms a connection portion with another substrate. The temperature signal is sent to the control board constituting the control circuit 23 of the power converter 200. The control board equipped with the control circuit receives the temperature signal, determines whether the temperature is higher than the temperature that should be warned, and if it is higher than the temperature that should be warned, implements measures such as stopping the operation and issuing a warning. . Therefore, abnormality detection based on the respective characteristics of the PTC thermistors 6a to 6e is possible, and appropriate detection is possible at each terminal fastening portion. Furthermore, the abnormality can be detected by detecting an abnormality before the terminal portion is damaged by heat and further transmitting the control signal as it is when returning. By connecting the PTC thermistors 6a to 6e in series, it is possible to detect the temperature corresponding to each design temperature, and the size and cost can be reduced as compared with the case where each control circuit is provided. Is possible. Furthermore, since the reset circuit for recovery can be shared at the time of recovery, it is possible to reduce the size and cost.

  Furthermore, according to the above configuration, the temperature detection substrate 5 is vertically arranged between the primary side terminal fastening portion 2a and the secondary side terminal fastening portion 2b, that is, in the central portion of each conductive plate 4. The temperature detection of both the primary side terminal fastening part 2a and the secondary side terminal fastening part 2b becomes easy. The temperature rise of the primary side terminal fastening part 2a or the secondary side terminal fastening part 2b is transmitted by thermal radiation, and temperature detection is performed. Therefore, temperature detection in a wider range is possible. In addition, since the temperature detection board is placed vertically to the conductive plate, it is possible not only to avoid an increase in the exclusive area but also to collect heat uniformly from the temperature detection range, enabling more accurate temperature detection. It becomes.

  Moreover, the terminal block 10 of this Embodiment is applicable not only to the power converter 200 but the terminal block used for terminal connection in other apparatuses, such as a distribution board.

Embodiment 2. FIG.
FIG. 8 is a perspective view showing the terminal block 10 according to the second exemplary embodiment of the present invention. 9A is a top view of the terminal block, and FIG. 9B is a cross-sectional view taken along the line BB in FIG. In addition, about the structure similar to the said Embodiment 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. In the first embodiment, the case where the temperature detection substrate 5 is installed in the central portion of the terminal block body 1 is shown. However, in the second embodiment, an example in which the temperature detection substrate 5 is attached to the conductive plate 4. Show.

  The conductive plate 4 is extended toward the primary wiring part 3a side, which is an external wiring, with respect to the terminal block shown in the first embodiment shown in FIG. 5 is fixed. Although the fixing positions of the temperature detection substrate 5 are different, the PTC thermistors 6a to 6e are positions where they overlap with the conductive plate installation region where the conductive plate 4 is installed in plan view, that is, the bolts 20 that are terminal screws of the primary side terminal fastening portion 2a. It attaches to the position which can detect the temperature of the volt | bolt 20, such as the outside. That is, the conductive plate 4 has an extended portion that extends toward the primary terminal fastening portion 2a, and the temperature detection substrate 5 is provided so as to contact the extended portion. The temperature detection substrate 5 is in contact with each extending portion of the five conductive plates 4 and extends in a direction orthogonal to the five conductive plates 4. Since the other structure is the same as that of the terminal block of Embodiment 1 shown in FIG. 1, description is abbreviate | omitted. The PTC thermistors 6a to 6e may be provided in the secondary side terminal fastening portion 2b, or may be provided in both. However, the primary and secondary side terminal fastening portions 2a and 2b are electrically and One side is sufficient because of good thermal connection.

  By adopting the above structure, the PTC thermistors 6a to 6e, which are thermal elements attached to the temperature detection substrate 5, are connected to the conductive plate 4 having better heat conduction than the terminal block body 1 through the temperature detection substrate 5. It is in thermal contact, and the temperature of the conductive plate 4 can be measured more accurately. That is, when heat is generated due to loosening of the bolts 20 that are terminal screws, heat is transmitted to the conductive plate 4 having good thermal conductivity, so that a more reliable operation can be expected as compared with the first embodiment. In the second embodiment, it goes without saying that the effects of the configuration of the first embodiment are exhibited.

  Furthermore, according to the above configuration, the PTC thermistors 6a to 6e can be mounted between the temperature detection substrate 5 and the conductive plates 4, so that the conductive plates 4 and the PTC thermistors 6a to 6e can be mounted. It is in contact with 6e and has good temperature detectability. Further, the temperature detection substrate 5 can be formed only on the primary terminal fastening portion 2a side, for example, and the primary side terminal fastening portion that is frequently attached and detached and is likely to generate heat due to loosening of the terminal screw is reliably detected. By making it possible, the reliability is further improved. Furthermore, by providing the temperature detection substrate at the terminal fastening portion on the side where the attachment / detachment is frequently performed, maintenance can be performed without separately providing an opening for maintenance. That is, the maintainability of the PTC thermistor or the temperature detection substrate is also improved by using the opening for fastening the primary side terminal fastening portion.

  In the first and second embodiments, the power converter used in the photovoltaic power generation system and the terminal block used in the power converter have been described. For example, an inverter device that performs motor control or a heater is controlled. Needless to say, the present invention can be applied to a power device for controlling a relatively large power, such as a temperature control device, and a terminal block used for the power device. At this time, the PTC thermistor may not only detect the temperature of the conductive plate, but may also detect the temperature of the terminal block.

  Also, the primary side wiring may be treated as input wiring and the secondary side wiring as output wiring, but in this embodiment, the power supply terminal block is the center, the terminal block external wiring is the primary wiring, The internal wiring is handled as the secondary wiring. Therefore, the primary wiring includes wiring connected to the input terminal from the solar cell module and wiring connected to the output terminal to the load, and the secondary wiring includes wiring connected to the power converter and the like. However, the definition of primary and secondary is not limited to this.

  In the first and second embodiments, a PTC thermistor is provided for each conductive plate. However, it is not always necessary to provide a PTC thermistor for each conductive plate, and one PTC thermistor may be provided for every two sheets, or one as a whole. Or two PTC thermistors are provided for each conductive plate. Two or more PTC thermistors may be juxtaposed, or may be provided in the primary side terminal fastening portion and the secondary side terminal fastening portion, respectively. According to this configuration, it is possible to detect a special temperature state of the primary side terminal fastening portion and the secondary side terminal fastening portion or the PTC thermistor installation location with high accuracy.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  DESCRIPTION OF SYMBOLS 1 Terminal block main body, 1c Recessed part, 2a Primary side terminal fastening part, 2b Secondary side terminal fastening part, 3a Primary side wiring part, 3b Secondary side wiring part, 4 Conductive plate, 5 Temperature detection board, 6a-6e PTC Thermistor, 7 connector, 10 terminal block, 23 control circuit, 30 crimp terminal, 30a primary crimp terminal, 30b secondary crimp terminal, 31a, 31b crimp tube, 32a primary wiring material, 32b secondary wiring material, 100 Solar cell module, 200 power converter, 300 distribution board, 400 AC power supply, 500 load.

Claims (12)

A terminal block body having a primary terminal fastening portion to which the primary wiring is connected and a secondary terminal fastening portion to which the secondary wiring is connected;
A conductive plate attached to the terminal block main body and connecting the primary side terminal fastening portion and the secondary side terminal fastening portion;
A terminal block or a PTC thermistor for detecting the temperature of the conductive plate;
A terminal block comprising: The terminal block body consists of resin blocks,
The terminal block according to claim 1, wherein the PTC thermistor is mounted in a region where the conductive plate is installed. The PTC thermistor is composed of a plurality of
The terminal block according to claim 1, wherein a plurality of the PTC thermistors are connected in series. The conductive plate is composed of a plurality,
The terminal block according to claim 3, wherein the temperature of the Curie point of the PTC thermistor is set independently for each of the conductive plates. The terminal block according to claim 3 or 4, wherein one PTC thermistor is arranged for each of the conductive plates. The PTC thermistor is mounted on a temperature detection substrate,
The said temperature detection board | substrate was distribute | arranged perpendicularly | vertically with respect to the said electrically conductive board between the said primary side and secondary side terminal fastening parts, The Claim 1 characterized by the above-mentioned. Terminal block. The PTC thermistor is mounted on a temperature detection substrate,
The conductive plate includes an elongated portion that is elongated on one side of the primary side and secondary side terminal fastening portions,
6. The terminal block according to claim 1, wherein the temperature detection substrate is brought into contact with an elongated portion of the conductive plate. 7. The terminal block according to any one of claims 1 to 7,
A power converter that converts power input from the input unit mounted on the terminal block and outputs the power from the output unit;
A power circuit comprising: a control circuit that determines that the temperature is abnormal and cuts off the supply of power when the output resistance of the PTC thermistor is higher than a resistance value at a temperature at which the abnormality is detected; . The PTC thermistor is composed of a plurality of
The control circuit determines that the temperature is abnormal when a combined resistance value obtained by connecting the plurality of PTC thermistors in series is larger than a resistance value when one PTC thermistor detects an abnormality. The power device according to claim 8, wherein the power supply is cut off. The power device according to claim 8 or 9, wherein the control circuit has an abnormal signal transmission function of transmitting an abnormal signal when it is determined that the temperature is abnormal. 11. The control circuit according to claim 8, wherein the control circuit has a recovery function that restores power supply when a reset operation is performed after determining that the temperature is abnormal and interrupting power supply. 11. The power device according to claim 1. The power device according to any one of claims 8 to 11, further comprising: a power conversion unit that converts DC power input from the primary side into AC power and supplies the AC power to the secondary side.

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