JP4321378B2 - Switchgear - Google Patents

Description

  The present invention relates to an opening / closing device that performs opening / closing of a load by phase control.

Conventionally, in a switchgear that turns on and off a load that operates with an AC power supply using a relay contact, the method of suppressing inrush current and arc discharge that flows through the load when it is turned on is to phase the opening and closing of the relay contact near the zero cross of the AC power supply voltage. There was something to control (for example, patent document 1).
JP-A 61-51720

  By the way, since the switching device by phase control as seen in the above-mentioned Patent Document 1 is based on the premise that the load power source is a commercial AC power source, for example, when the load power source is a DC power source, it opens and closes. Cannot be used to open and close a load using a DC power supply. In other words, it was exclusively for AC loads.

  On the other hand, when installing as an internal unit in a distribution board, it is necessary to check the operation before installing it, but it is necessary to connect the detection terminal of the phase detection circuit to a commercial AC power source for phase detection, so wiring There was also a problem that it took time and effort to connect.

  Also, when checking the operation after it is installed in the distribution board, the breaker switching contact is inserted into the power circuit from the connection point of the detection terminal of the phase detection circuit, so the operation check cannot be performed when the breaker is shut off. It was necessary to insert a breaker one by one.

  The present invention has been made in view of the above points. The object of the present invention is to control the phase when the power supply to the load is a commercial AC power supply, and when the load power supply is a DC power supply. An object of the present invention is to provide an opening / closing device capable of opening and closing a contact portion even when not connected.

  In order to achieve the above-described object, according to the first aspect of the present invention, a phase detection unit that outputs a phase detection signal when a detection terminal is connected to a load power supply path and a voltage applied to the detection terminal is within a predetermined range. And an operation means for outputting an operation signal, a drive unit for opening and closing a contact portion inserted between the load power source and the load, and a signal processing for outputting an open / close signal for causing the drive unit to open and close the contact portion A phase control function for outputting the open / close signal at a predetermined phase after a predetermined time when the operation signal is input to the signal processing unit, and input of the operation signal. If present, the drive means is provided with an immediate control function for outputting the open / close signal.

  According to the first aspect of the present invention, it is possible to perform the operation check before being incorporated in the distribution board in a state in which the load power supply is not connected, and it is not necessary to connect the load power supply when checking the operation. As a result, the time required for the operation check can be shortened, and the operation can be performed even when a DC power source is used as the load power source. Therefore, the load used is not limited to AC.

  According to a second aspect of the present invention, in the first aspect of the invention, the signal processing unit includes a determination function for determining whether an AC power supply is connected as a load power supply, and the determination function is an AC power supply. The phase control function is made to function when it is determined, and the immediate control function is made to function when it is not an AC power source.

  According to the invention of claim 2, the signal processing unit can determine whether the phase control function is automatically functioned or the immediate control function is functioned depending on the presence and type of the load power supply, and the user can set each one. There is no need to do it and it is easy to use.

  According to a third aspect of the present invention, in the second aspect of the present invention, the determination function determines whether an AC power source is connected as a load power source in an output state of the phase detection signal.

  According to the third aspect of the present invention, the phase detection signal used for the opening / closing drive of the contact portion by phase control can be used for the determination of the connected power source, so that the determination processing of the signal processing unit is simplified.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the determination function includes a voltage waveform in which an AC power source stored in advance is applied to the phase detection terminal of the phase detection unit, and a voltage across the phase detection terminal during operation. It is characterized in that it is determined whether an AC power source is connected as the load power source by comparing with a waveform.

  According to the fourth aspect of the present invention, it is possible to determine the connected power source without being affected by noise or the like.

  According to a fifth aspect of the present invention, in the second aspect of the present invention, an exciting coil of an AC electromagnetic relay is connected in parallel to a load power source, and the determination function is based on an open / close state of a relay contact of the electromagnetic relay. It is determined whether or not an AC power source is connected as a load power source.

  According to the invention of claim 5, since the connection power source can be determined based on the open / closed state of the relay contact, it can be realized without using a highly functional circuit element such as a microcomputer in the signal processing unit.

  The invention of claim 6 is characterized in that in the invention of claim 1, a manual changeover switch for switching between a phase control function and an immediate control function of the signal processing unit is provided.

  According to the sixth aspect of the present invention, since it is possible to determine whether the phase control function is to function or the immediate control function to be functioned in the on / off state of the manual changeover switch, the signal processing unit is provided with a microcomputer or the like. This can be realized at low cost without using high-performance circuit elements.

  In the present invention, it is possible to check the operation before installation in the distribution board in a state in which the power supply for the load is not connected, and it is not necessary to connect the power supply for the load when checking the operation. The operation time can be shortened, and it is possible to operate even when a DC power source is used as the power source for the load. Therefore, there is an effect that the load used is not limited to the AC power source.

Embodiments of the present invention will be described below.
(Embodiment 1)
FIG. 1 shows a configuration diagram of a switchgear 1 according to this embodiment. In this embodiment, a relay contact 3a of a relay 3 such as a polarized electromagnetic relay is used as a contact portion for opening and closing a load 2.

  As a drive unit for opening and closing the contact portion, a relay drive unit 4 is provided that opens and closes by passing an excitation current through the excitation coil of the relay 3, and a trigger for opening and closing the relay 3 with respect to the relay drive unit 4. A signal processing unit 5 composed of a microcomputer (hereinafter abbreviated as a microcomputer) that outputs an opening / closing signal S0 serving as a signal, a phase detection unit 6 that performs phase detection for phase control of the opening / closing drive of the relay 3, and a signal processing unit 5 And an operation unit 7 for supplying an operation signal to the relay 3 and a power supply unit 8 for supplying driving power to the relay 3 and operating power to the units 4 to 6.

  The phase detector 6 detects the zero-cross phase of the power supply voltage when the load power source 9 connected to the load 2 connected via the relay contact 3a of the relay 3 is an AC power source. Is connected to a load electric circuit between the load power source 9 and the relay contact 3a. When the load power source 9 is a commercial AC power source as shown in FIG. When the voltage between the phase detection terminals 6a and 6a is within a predetermined voltage range of ± around the zero cross, the output is set to the “H” level, thereby processing the pulsed phase detection signal S1 shown in FIG. It outputs to the part 5. On the other hand, when the load power supply 9 is a DC voltage, the voltage between the phase detection terminals 6a and 6a exceeds the predetermined voltage range, so that the output is fixed at the “L” level, and when the load power supply 9 is not connected. Since the voltage between the phase detection terminals 6a and 6a becomes 0V, the output is fixed at the “H” level.

  Based on the output state of the phase detection unit 6, the signal processing unit 5 determines whether or not a commercial AC power source is connected between the phase detection terminals 6a and 6b, and the determination result of the determination function indicates that the commercial AC power Functions when the power supply is not connected, and immediately after the operation signal S2 from the operation unit 7 is input, an immediate control function for outputting the opening / closing signal S0 to the relay drive unit 4 and a commercial AC power supply are connected. And a phase control function for outputting the open / close signal S0 to the relay drive unit 4 after a predetermined time based on the phase detection signal S1 after the operation signal S2 is input.

  The operation unit 7 may be provided in the apparatus main body, or may be provided in a system installed at a position distant from the apparatus main body. In any case, the switch operation signal S2 is sent to the signal processing unit 5. To send.

  The power source unit 8 is connected to the commercial AC power source 10 independently of the load power source 9 to obtain the operating DC power source of each unit 4 to 6 and the driving power source of the relay 3.

  The relay 3 is a two-winding or one-winding type polarized electromagnetic relay, and the direction of the exciting current flowing through the exciting coil is controlled by the relay driving unit 4 when the exciting current flows through the exciting coil for setting or resetting. This reverses the electromagnetic mechanism to reverse the state of the relay contact 3a from the current state. After the reversing operation, the state is maintained until the reversing operation is performed by the next excitation.

  When the open / close signal S0 from the signal processing unit 5 is input, the relay driving unit 4 triggers the relay current to flow through the exciting coil of the relay 3 as described above to drive the relay 3 in reverse.

  Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG.

  First, in the circuit configuration of FIG. 1, when the commercial AC power supply 10 is connected to the power supply unit 8 and the power supply to the units 5 to 7 is turned on, the switchgear 1 enters a standby state.

  In the case of FIG. 1, a load power supply 9 is connected to both ends of the phase detection terminals 6a and 6a of the phase detector 6, and a power supply voltage is applied. Here, if the load power supply 9 is a commercial AC power supply, the phase detection unit 6 outputs the pulsed phase detection signal S1 shown in FIG. 2B to the signal processing unit 5 at a constant cycle corresponding to the zero cross phase. To do. The signal processor 5 determines that the load power source 9 is a commercial AC power source by inputting the phase detection signal S1 at a constant cycle, and causes the phase control function to function based on the determination result (step ST1).

  After this determination processing, the signal processing unit 5 enters an operation signal S2 waiting state in step S2, and when the operation signal S2 is input from the operation unit 7 in this input waiting state, the input of the phase detection signal S1 is waited from this input time point ( Step ST3). When the first rising edge of the phase detection signal S1 is detected after waiting for the input, a predetermined fixed delay time is counted from the detection timing, and when the delay time count ends, the open / close signal S0 is sent to the relay drive unit. 4 (step ST4).

  When the open / close signal S0 is input, the relay drive unit 4 excites the relay 3 to invert the relay contact 3a. In the case of FIG. 1, the relay contact 3 a is reversed from the open state to the closed state, and the load 2 and the load power source 9 are connected.

  In addition, the signal processing unit 5 determines whether or not the open / close state of the relay contact 3a is reversed compared to immediately before step S4 after the open / close signal S0 is output, and is determined to be reversed. If so, the process returns to step ST1, and if it is determined that the relay contact 3a is not reversed, the process returns to step ST4 to output the open / close signal S3 again in order to reverse the open / close state of the relay contact 3a. In order to detect contact reversal, an appropriate method such as detection of load current or detection of voltage across the load may be used.

  Here, the relay contact 3a is set so that the timing at which the relay contact 3a reverses after the opening / closing signal S3 is received is near the zero cross point of the voltage of the commercial AC power supply 9. Thus, it is possible to suppress the inrush current from flowing to the load 2 at the time of closing (ON), and conversely, the arc discharge at the relay contact 3a can be suppressed when opening (OFF).

  By the way, when the load power supply 9 is a DC power supply, the voltage between the phase detection terminals 6a and 6a is constant, so that the output of the phase detection unit 6 remains at the “L” level (0 V). Therefore, the signal processing unit 5 determines that the load power source 9 is not a commercial AC power source since the pulsed phase detection signal S1 is not input at a constant period. Based on this determination, the immediate control function is made to function in step ST1, The input standby state for the operation signal S2 in step ST6 is entered. When the operation signal S2 is input from the operation unit 7 in this input waiting state, the signal processing unit 5 immediately outputs the open / close signal S0 to the relay drive unit 4 (step ST7). When the open / close signal S0 is input, the relay drive unit 4 excites the relay 3 to invert the relay contact 3a as described above. Similarly to the above, the signal processing unit 5 determines whether or not the open / close state of the relay contact 3a is reversed as compared with the state immediately before step S4 after the open / close signal S0 is output. If it is determined, the process returns to step ST1, and if it is determined that it is not reversed, the process returns to step ST7 to output the open / close signal S3 again in order to reverse the open / close state of the relay contact 3a.

  For example, when the operation check before the switchgear 1 is installed in the distribution board is performed, power is supplied from the power supply unit 8 to each of the units 4 to 6 without the load power supply 9 being connected. In this case, since no voltage is applied to the phase detection terminals 6a and 6a of the phase detection unit 6, the output of the phase detection unit 6 is fixed to the “H” level. Therefore, as in the case where the load power source 9 is a DC power source, the signal processing unit 5 does not receive the pulsed phase detection signal S1 at a constant period, and the signal processing unit 5 is the same as in the case of the DC power source described above. It is determined that the load power source 9 composed of a commercial AC power source is not connected to the terminal, and the immediate control function is made to function in step ST1, and the operation signal S2 input standby state in step ST6 is entered. Thereafter, the relay 3 is driven to open and close without phase control by the same processing as that when the load power source 9 is a DC power source.

  That is, the operation can be confirmed without forming a load electric circuit to which the load power supply 9 is connected.

  In addition, when checking the operation after being installed in the distribution board, it can be performed even when the load circuit is interrupted by a breaker. Also in this case, since the voltage between the phase detection terminals 6a and 6a becomes 0V, the signal processing unit 5 determines that the load power source 9 is not a commercial AC power source in the same manner as described above, and causes the immediate control function to function, and the operation signal S2 Is input to the relay drive unit 4 to drive the relay 3 to open and close. In this case, since the load power supply 9 is not energized, it can be safely performed even if the operation is confirmed in the wiring construction state.

  FIG. 3B is a flowchart showing a specific determination process in the above-described step ST1 for determining whether the signal processing unit 5 functions the phase control function or the immediate control function. The operation of the signal processing unit 5 at step ST1 will be described.

  First, when the processing shifts to step ST1, the signal processing unit 5 sets the count value Tsig = 0 ms of a built-in timer (not shown). As a count value threshold value to be determined as not being a commercial AC power source, a time (for example, 11 mS) that is about 10% longer than 10 ms, which is a half cycle of a commercial frequency of 50 Hz, is set in advance in a built-in memory (not shown). (Step ST10). In step ST11, the count value Tsig of the built-in timer (not shown) is compared with the threshold value Tover, and if the count value Tsig does not exceed the threshold value Tover, the rising edge of the next output of the phase detector 6 is determined in step ST12. To check. That is, it is checked whether or not the phase detection signal S1 is periodically output (step st2). Then, the processes in steps ST11 and ST12 are repeated until the count value Tsig exceeds the threshold value Over or a rising edge is detected.

If the edge is detected in step ST12 before the count value Tsig exceeds the threshold value Tover, it is determined that a commercial AC power source is connected to the phase detection terminals 6a and 6b of the phase detection unit 6, and signal processing is performed. The unit 5 performs processing for causing the phase control function to function. When it is determined in step ST11 that the count value Tsig has exceeded the threshold value Over, the signal processing unit 5 does not receive the periodic phase detection signal S1, that is, It is determined that a commercial AC power source is not connected to the phase detection terminals 6a and 6b of the phase detector 6, and a process for causing the immediate control function to function is performed.
(Embodiment 2)
In the first embodiment, whether or not the commercial AC power source is connected to the phase detection terminals 6a and 6a is determined based on whether or not the signal processing unit 5 outputs the periodic phase detection signal S1 from the phase detection unit 6. However, in this embodiment, by comparing the waveform of the voltage applied to the phase detection terminals 6a and 6a of the phase detection unit 6 with the voltage waveform registered in advance, the phase detection terminals 6a and 6b are commercialized. It is characterized in that it is determined whether or not a load power source 9 composed of an AC power source is connected.

  That is, in the present embodiment, the phase detection unit 6 includes the phase detection terminals 6a. The voltage between 6b is resistance-divided internally, and the divided voltage waveform signal S3 (see FIG. 5B) is different from the above-described phase detection signal S1 corresponding to the zero cross as shown in the circuit configuration of FIG. A function of outputting to the signal processing unit 5 through a signal line is provided. Further, the signal processing unit 5 stores a total of 20 voltage values from zero to 1 ms at intervals of 1 ms from the sine wave shown in FIG. 5C in which the peak of the commercial AC power supply voltage waveform shown in FIG. 5A is dropped. The phase detection terminals 6a and 6a of the phase detection unit 6 compare the stored internal voltage (not shown), the stored voltage data, and the voltage waveform voltage sent from the phase detection unit 6. A determination function is provided for determining whether or not a commercial AC power supply is connected.

  4 are the same as those of the first embodiment, the same components as those of FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 is a flowchart showing the processing operation of the determination function of the signal processing unit 5, and this processing operation corresponds to the processing operation in step ST1 of FIG.

  Thus, in step ST20, the signal processing unit 6 takes in the voltage waveform signal S3 sent from the phase detection unit 5 and sees whether or not there is a period during which the voltage does not become zero, and the period when the voltage becomes zero. If it is not a certain time, it is determined that the power source (load power source 9) connected to the phase detection terminals 6a and 6a of the phase detector 6 is not a commercial AC power source, and the immediate control function is made to function.

  On the other hand, when the voltage becomes zero, the voltage is sampled and stored once in a built-in memory (not shown) for 20 ms every 1 ms from the time of zero voltage in step S21. In step ST22, all of the stored 20 voltage values and the previously stored 20 voltage values of the sine wave are compared, and the input voltage value is compared with the previously stored voltage value. If within ± 5%, the same one is considered, and if the same one is 15 or more out of 20, for example, the power supply connected to the phase detection terminals 6a and 6a of the phase control unit 6 (for load) If the power source 9) is determined to be a commercial AC power source, and less than 15 units, it is determined that there is no commercial AC power source. That is, it is determined including the state where the power source is not connected to the phase detection terminals 6a and 6a of the phase detector 6.

  When it is determined that the power supply is a commercial AC power supply in this way, the signal processing unit 5 causes the phase control function to function and proceeds to step ST2 in FIG. 3A, and when it is determined that the power supply is not a commercial AC power supply. The immediate control function is activated, and the process proceeds to step ST6 in FIG. When the phase control function is activated, phase control based on the phase detection signal S1 corresponding to the zero cross point is performed in the same manner as in the first embodiment.

  As described above, also in the present embodiment, if the load power supply 9 is a commercial AC power supply, the phase control for opening and closing the relay 3 is performed after a predetermined time delay from the input of the operation signal S2, and the load power supply 9 In the case of not being connected or in the case of a DC power supply, immediate control for opening and closing the relay 3 can be performed as soon as the operation signal S2 is input, and there is an advantage similar to that of the first embodiment.

  In the present embodiment, the connection of the commercial AC power supply is not determined based on the overall matching of the voltage waveforms, but can be determined without being affected by noise or distortion by allowing the degree of matching. The allowable value of ± 5% is an example, and is actually set in consideration of fluctuations in the voltage waveform. Therefore, it becomes difficult to make a misjudgment together with storing the voltage value of the voltage waveform.

(Embodiment 3)
In the first and second embodiments, the signal processing unit 5 determines whether or not the load power source 9 including a commercial AC power source is connected based on the output of the phase detection unit 6. As shown in FIG. 7, the electromagnetic relay 11 for alternating current which connects the exciting coil 11a to a load power supply path is provided, and the contact signal of the normally open relay contact 11a of the electromagnetic relay 11 is output to the signal processing part 5, for example. It is supposed to be. On the other hand, the signal processing unit 5 determines whether or not the load power source 9 consisting of a commercial AC power source is connected to the load power source path based on the contact signal whether or not the electromagnetic relay 11 operates and the relay contact 11a is inverted. It has a judgment function. The phase control function and the immediate control function of the signal processing unit 5 operate in the same manner as in the first embodiment, and other circuit configurations are the same as those in the first embodiment, so that the description thereof is omitted and the same components are denoted by the same reference numerals.

  Thus, the processing operation of the signal processing unit 5 at step ST1 in FIG. 3A is a process for determining whether or not the relay contact 11a of the electromagnetic relay 11 is closed from the acquired contact signal. Is closed, it is determined that the load power source 9 consisting of a commercial AC power source is connected and the electromagnetic relay 11 has been operated, and the opening is reversed to step ST2 in FIG. In this case, it is determined that the electromagnetic relay 11 is not operating, that is, the commercial AC power source is not connected as the load power source 9, and the process proceeds to step ST6 in FIG. Other processing operations are the same as those in the embodiment, and a description thereof will be omitted.

  As described above, in this embodiment, in order to determine whether to perform phase control or immediate control, it is determined whether or not the load power supply 9 is a commercial AC power supply based on the contact signal of the relay contact 11a of the electromagnetic relay 11. Since the determination is made, the built-in memory (not shown) of the signal processing unit 5 is not required as in the first and second embodiments, and the determination process is simplified, so that the signal processing is performed without using a microcomputer. The part 5 can also be configured.

Further, the relay contact 11a for obtaining the contact signal may be a normally closed contact. In this case, it is determined that the load power source 9 composed of a commercial AC power source is connected when the contact is opened.
(Embodiment 4)
In the first and second embodiments, the output of the phase detection unit 6 is used, and in the third embodiment, the contact signal of the AC electromagnetic relay 11 is used to determine whether or not a commercial AC power supply is connected as the load power supply 9. In this embodiment, a manual changeover switch 12 is provided as shown in FIG. 8 in place of the electromagnetic relay 11 of the third embodiment. The on / off signal of the changeover switch 12 is given to the signal processing unit 5 as a selection signal for phase control or immediate control so that it can be manually selected.

  The signal processing unit 5 performs the selection process at step ST1 in FIG.

  As described above, in this embodiment, the determination of whether to perform phase control or immediate control is performed by the on / off signal of the manual changeover switch 12, so Since the built-in memory is not required and the determination process is further simplified, the signal processing unit 5 can be configured without using a microcomputer.

1 is a circuit configuration diagram of Embodiment 1. FIG. FIG. 4 is a waveform diagram for explaining operation of the first embodiment. 3 is a flowchart for explaining the operation of the first embodiment. 6 is a circuit configuration diagram of Embodiment 2. FIG. FIG. 6 is a waveform diagram for explaining operation of the second embodiment. 6 is a flowchart for explaining operations of the second embodiment. 6 is a circuit configuration diagram of Embodiment 3. FIG. FIG. 6 is a circuit configuration diagram of a fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Switchgear 2 Load 3 Relay 3a Relay contact 4 Relay drive part 5 Signal processing part 6 Phase detection part 7 Operation part 8 Power supply part 9 Power supply 10 for load Commercial AC power supply S0 Open / close signal S1 Phase detection signal S2 Operation signal

Claims (6)

A phase detection unit that outputs a phase detection signal when a detection terminal is connected to the load power supply path and a voltage applied to the detection terminal is within a predetermined range, an operation means that outputs an operation signal, a load power supply, and a load And a signal processing unit for outputting an opening / closing signal for driving the contact part to open and close the contact part. The signal processing part inputs the operation signal. A phase control function that outputs the open / close signal at a predetermined phase after a predetermined time with reference to the phase detection signal, and an immediate control function that outputs the open / close signal to the drive means when the operation signal is input. A switchgear characterized by comprising: The signal processing unit includes a determination function for determining whether or not an AC power supply is connected as a load power supply. When the determination function is determined to be an AC power supply, the phase control function is 2. The opening / closing device according to claim 1, wherein an immediate control function is activated when there is not. 3. The switchgear according to claim 2, wherein the determination function determines whether or not an AC power source is connected as a load power source in an output state of the phase detection signal. The determination function compares a voltage waveform in which an AC power source stored in advance is applied to the phase detection terminal of the phase detection unit and a voltage waveform at both ends of the phase detection terminal during operation, and the AC power source is used as the load power source. The switchgear according to claim 2, wherein it is determined whether or not it is connected. An exciting coil of an AC electromagnetic relay is connected in parallel with the load power supply, and the determination function determines whether an AC power supply is connected as the load power supply based on the open / closed state of the relay contact of the electromagnetic relay. The switchgear according to claim 2, wherein the switchgear is determined. 2. The switchgear according to claim 1, further comprising a manual changeover switch for switching between a phase control function and an immediate control function of the signal processing unit.

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