JP4773854B2 - Electromagnetic switchgear - Google Patents

Description

  The present invention relates to an electromagnetically operated switchgear that opens and closes a three-phase AC line by driving an electromagnetic actuator having a fixed iron core, a coil, and a movable iron core connected to a movable contact of the switch.

  In this type of conventional switchgear, the circuit breaker in the U-phase vacuum vessel is connected to the operation device via the operating rod and drive rod, and the circuit breaker in the V-phase vacuum vessel is connected via the operation rod and drive rod. The W-phase circuit breaker is connected to the actuator via the operation rod and drive rod, and electromagnetic force generated from the electromagnet is applied to the drive rod and operation rod during the closing operation by each actuator. Each circuit breaker is turned on, and when the operation device is opened, the elastic force accumulated in the tripping spring is applied to the drive rod and operation rod to open each circuit breaker and is generated from the operation device of each phase. The operating force is transmitted to the other two phases via the link mechanism, and the operating devices for each of the three phases are turned on or off at once (see Patent Document 1).

  In another conventional switchgear of this type, the circuit breaker is opened and closed by issuing an open / close command from the microprocessor unit. The voltage / current value of the circuit (main circuit) that is going to break the circuit breaker is measured, and for example, the current is cut off at the point where the current crosses zero. Each of the three phases operates individually according to the current phase of the main circuit (see Patent Document 2).

Japanese Patent Laying-Open No. 2005-190919 (paragraphs 0025 to 0028, FIG. 1) USP 5638296 (column 3, lines 4 to 11, column 8, line 57 to column 9, line 25, column 19, line 8 to column 20, line 56, FIGS. 3 and 6A)

For example, in a switchgear as shown in Patent Document 1,
1. A link structure that connects the three phases is required, and the circuit breaker becomes larger.
2. With a large circuit breaker, the link structure becomes large and expensive.
There was a problem.

For example, in an opening / closing device as shown in Patent Document 2,
1. Since the electrodes are driven in accordance with the phase of the main circuit current, a means for accurately observing the voltage and current of the main circuit is required, resulting in high costs.
2. Since most of the switchgears that have been frequently used in the past are switchgears that can operate three phases at once, the conventional peripheral equipment may not be diverted, resulting in high costs.
There was a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an electromagnetically operated switchgear that can operate an AC three-phase at once in a simple and inexpensive manner.

An electromagnetically operated switchgear according to the present invention includes a switch and an electromagnetic controller for driving the switch for each phase of a three-phase AC line, and the electromagnetic controller is movable between a fixed iron core, a coil, and a switch. An electromagnetic core that has a movable iron core connected to the contact and performs three-phase collective opening and closing of the three-phase AC line at the same three-phase timing by driving the movable iron core by energizing the coil based on a three-phase collective opening / closing pole command In the operation switchgear,
By adjusting the timing of energizing the coil of each phase for each phase, even if there is a variation in the switching pole time of each switch, each phase switch can be opened and closed from a three-phase batch switching pole command. Coil energization timing adjusting means for keeping the phase opening / closing timing of the three-phase AC line, which is the time until pole operation, is within the same predetermined range for the three phases.

  As described above, the present invention includes the coil energization timing adjusting means that adjusts the timing of energizing the coils of each phase for each phase and keeps the phase opening and closing timing of the three-phase AC line within a predetermined range. Therefore, it is possible to obtain an electromagnetically operated switchgear that can perform a three-phase collective operation at a low cost without requiring a large-sized link structure in order to suppress operation variation. Further, it is possible to obtain an electromagnetically operated switchgear that is highly compatible with a conventional switchgear that presupposes mechanical three-phase collective operation and that can perform inexpensive three-phase collective operation.

Embodiment 1 FIG.
1 is a diagram showing a configuration of a vacuum circuit breaker as an electromagnetically operated switchgear according to Embodiment 1 of the present invention. In FIG. 1, a vacuum valve 3 which is a switch has a switching contact 5 housed in a vacuum container. The open / close contact 5 includes a fixed contact 5a disposed below the FIG. 1 and a movable contact 5b disposed opposite to the fixed contact 5a with a predetermined gap in the vertical direction of FIG. Yes. A drive rod 7 is fixed to the movable contact 5b, and the movable contact 5b and the drive rod 7 constitute a movable portion 6. The movable portion 6 is connected to the movable iron core 16 of the electromagnetically operated electromagnet 10 through the contact pressure spring 8 and the spring receiver 9.

  The electromagnetically operated electromagnet 10 has a closing coil 13, an opening coil 14, and a movable iron core 16. The closing coil 13 and the opening coil 14 as driving electromagnetic coils are wound in an annular shape and are arranged at a predetermined interval in the axial direction. A movable iron core 16 formed of a ferromagnetic material is disposed in the axial direction at each axial center of the closing coil 13 and the opening coil 14. A cylindrical permanent magnet 17 is attached to the outer peripheral portion of the movable iron core 16.

The drive power supply device 20 includes a closing capacitor 23 and an opening capacitor 24. Note that the devices for charging the closing and opening capacitors 23 and 24 are not shown in FIG.
Closing command switches 33U, 33V, and 33W are provided on the connection line 25 that connects the closing capacitor 23 and the closing coil 13 of the drive power supply device 20, and the opening capacitor 24 and the opening of the drive power supply device 20 are opened. Opening command switches 34U, 34V, and 34W are provided on the connection line 26 that connects the electrode coil 14. Closed current measuring devices 43U, 43V, and 43W are provided on a connection line 27 that connects the closing capacitor 23 and the closing coil 13 of the drive power supply device 20 to the opening capacitor 24 of the drive power supply device 20. Opening current measuring devices 44U, 44V, and 44W are provided on the connection line 28 that connects the opening coil 14.

The switching pole time measuring device 50 is connected to the closing current measuring devices 43U to 43W and the opening current measuring devices 44U to 44W. The closing command switches 33 </ b> U to 33 </ b> W are configured on the closing timing adjustment circuit 53, and the closing timing adjustment circuit 53 receives information from the open / close pole time measuring device 50. The opening command switches 34 </ b> U to 34 </ b> W are configured on the opening timing adjustment circuit 54, and the opening timing adjustment circuit 54 receives information from the opening / closing pole time measuring device 50.
In the present invention, coil energization is performed by the closing current measuring devices 43U, 43V, 43W, the opening current measuring devices 44U, 44V, 44W, the switching pole time measuring device 50, the closing timing adjusting circuit 53, and the opening timing adjusting circuit 54. A timing adjustment unit is configured.

Next, the opening / closing operation of the vacuum circuit breaker, which is a premise for adjusting the coil energization timing of the present application, will be described. In addition, since the phase distinction is unnecessary here, the phase-specific codes are omitted.
In FIG. 1, the closing capacitor 23 and the opening capacitor 24 of the drive power supply device 20 are always charged to a predetermined voltage by a charging device (not shown). In the state where the movable contact 5 b shown in FIG. 1 is opened, when the closing command switch 33 is closed, the charge charged in the closing capacitor 23 is supplied to the closing coil 13. Then, the movable iron core 16 is driven downward in FIG. 1 in the axial direction by the current flowing in the closing coil 13, and the movable contact 5b is brought into contact with the fixed contact 5a via the contact pressure spring 8 and the drive rod 7, thereby closing the pole. To do. At this time, after the movable contact 5 b comes into contact with the fixed contact 5 a, the contact pressure spring 8 is further compressed, and the contact pressure between the contacts is secured by the compressed contact pressure spring 8. This state is maintained by the magnetic flux of the permanent magnet 17 attached to the magnet, and a closed state is obtained.

  In this closed state, when the opening command switch 34 is closed and an opening command is given, the charge charged in the opening capacitor 24 is supplied to the opening coil 14 and the current flowing through the opening coil 14 As a result, the movable iron core 16 is driven upward in FIG. 1 in the axial direction. When the movable iron core 16 starts moving upward, the contact pressure spring 8 that is initially compressed only extends, and the movable contact 5b and the drive rod 7 on the vacuum valve 3 side do not move. Thereafter, when the movable iron core 16 further moves upward, the movable contact 5b, the drive rod 7, the contact pressure spring 8, the spring receiver 9 and the movable iron core 16 move together to move upward, and the movable contact 5b is moved from the fixed contact 5a. This state is maintained, and this state is maintained by the magnetic flux of the permanent magnet 17 mounted around the movable iron core 16 so as to be in the open state.

Next, the switching pole time measuring device 50 and the closing / opening timing adjusting circuits 53 and 54, which are the main part of the first embodiment of the present invention, enabling the three-phase collective operation of the vacuum circuit breaker will be described. .
First, FIG. 2 shows an internal configuration of the open / close extreme time measuring apparatus 50. The open / close extreme time measuring device 50 uses a technique previously filed by the applicant of the present application and published internationally (WO2005 / 111164A1), and its outline will be described below.

In FIG. 2, the open / close pole time measuring device 50 includes an AD converter 61, a memory 62, an inflection point search means 63, and an open / close pole time prediction means 64.
The current of the closing coil 13 flowing in the connection line 27 is detected by the closing current measuring instruments 43U to 43W, and the current of the opening coil 14 flowing in the connecting line 28 is detected by the opening current measuring instruments 44U to 44W. Each is converted into a digital signal by the AD converter 61 and temporarily stored in the memory 62. Then, the inflection point on the current waveform during the opening or closing operation is obtained by the inflection point searching means 63, and the opening / closing time and closing of the vacuum circuit breaker are determined by the switching pole time prediction means 64 from the inflection point information. Calculate time for each phase. The calculation results of the opening time and closing time are output to the opening and closing timing adjustment circuits 54 and 53 described later.

  Here, with reference to FIG. 3, the procedure for obtaining the opening time from the waveform of the current flowing in the opening coil 14 will be described taking the opening operation as an example. In FIG. 3, the waveform of the current J flowing through the opening coil 14 becomes the maximum value imax at the time ts of the moving start point (Act 1) of the movable iron core 16, and after this time ts, the inflection point P, It has a minimum point Q at time tq. Times tp and tq represent the moment when the opening coil 14 is excited as the zero point (reference point) of the time axis.

  The stroke of the movable iron core 16 changes as shown by the stroke st in FIG. 3, and the movable iron core 16 starts to move at time ts (point Act1 in FIG. 3), which is the contact movement start time and the opening start time. At time (time at which the inflection point P occurs) tp, the movable contact 5b starts to separate from the fixed contact 5a (opening start point Act2 in FIG. 3), and thereafter the movable iron core 16 and the movable contact 5b are integrated. It moves, and at the time corresponding to the minimum point Q (time when the minimum point Q is generated) tq, the entire stroke is moved and the movable iron core 16 and the movable contact 5b are stopped and the opening is completed (the opening completion point in FIG. 3). Act3). That is, the time tq is a contact movement completion time, and is a contact opening completion time. Therefore, the opening time from the point of time when energization of the opening coil 14 is started is obtained as tq.

  The calculation of the opening time and the closing time by the switching pole time measuring device 50 is based on the coil current waveform in the closing operation immediately before the opening operation, which is the calculation target, for example. As for the closing time, if it is determined based on the coil current waveform in the opening operation immediately before the closing operation that is the subject of calculation, it is possible to accurately determine the change over time of the switching mechanism of the vacuum circuit breaker. The opening / closing extreme time can always be obtained. In addition, every time when a certain number of opening / closing operations has passed, the calculation of the opening / closing extreme time may be performed, and the immediately preceding measurement value may be used during that time.

Next, the closing timing adjustment circuit 53 that realizes the three-phase collective operation will be described with reference to FIG. In FIG. 4, the closing timing adjusting circuit 53 connected to the switching pole time measuring device 50 includes a memory 65, a predicted closing time comparing means 66, a closing timing control means 67, and a contact signal output means 68. The closing times of the U, V, and W phases input from the switching pole time measuring device 50 are compared by the predicted closing time comparing means 66 and the result is written in the memory 65.
When a closing operation command as a vacuum circuit breaker is issued, the closing timing control means 67 first sends a signal specifying the phase with the longest predicted closing time, for example, the V phase to the contact signal output means 68. The contact signal output means 68 receives it and outputs an ON signal to the V-phase closing command switch 33V, whereby a current flows from the closing capacitor 23 to the V-phase closing coil 13, V-phase closing operation is started.

Next, the closing timing control means 67 passes the delay time corresponding to the difference between the predicted time of the V phase with the longest predicted closing time and the predicted time of the next longest phase, for example, the W phase, to the W phase. Is sent to the contact signal output means 68, and the contact signal output means 68 receives it and outputs an ON signal to the W-phase closing command switch 33W. A current flows through the phase closing coil 13 and the W phase closing operation is started.
Furthermore, the closing timing control means 67 specifies the U phase through a delay time corresponding to the difference between the predicted time of the V phase with the longest predicted closing time and the predicted time of the shortest phase, for example, the U phase. The contact signal output means 68 receives the signal and outputs an ON signal to the U-phase closing command switch 33U. A current flows through the closing coil 13 and a U-phase closing operation is started.

  By performing the closing timing adjustment described above, even if there is a variation in the closing time of each phase, the closing timing of each phase is within a predetermined accuracy, and the three-phase batch closing operation is performed. Realize. In the opening operation, the opening timing adjustment circuit 54 realizes the three-phase collective opening operation in exactly the same manner as described above.

  As described above, the electromagnetically operated switchgear according to Embodiment 1 of the present invention sets the closing and opening timing for each phase based on the expected closing and opening times of each phase obtained by the switching pole time measuring device 50. Since it is equipped with the closing and opening timing adjustment circuits 53 and 54 that adjust for each phase and keep the opening and closing timing of each phase within a predetermined range, a large-sized link structure is not required to suppress operation variation and is inexpensive. It is possible to obtain an electromagnetically operated switchgear that can perform a three-phase collective operation and that is highly compatible with a conventional switchgear that presupposes a mechanical three-phase collective operation and that can perform a three-phase collective operation at low cost.

Embodiment 2. FIG.
FIG. 5 illustrates a closing timing adjustment circuit 53A of an electromagnetically operated switchgear according to Embodiment 2 of the present invention. Here, at the time of product shipment, the closing time of each phase is measured, and based on these measured values, the phase order and time difference for outputting an ON signal to the closing command switches 33U to 33W of each phase are obtained by calculation. Each time a closing operation command as a vacuum circuit breaker is issued, the data is read from the memory 65A, and the contact signal output means 68A sends an ON signal to the closing command switches 33U to 33W of the respective phases. Is output.

Assuming that the switching time of each phase hardly changes regardless of the change over time of the switching mechanism of the vacuum circuit breaker, the three-phase collective operation is realized as in the first embodiment, and the configuration for that However, there is an advantage that it is simpler and less expensive.
If the switching time of each phase is measured each time a certain number of switching times is passed and the contents of the memory 65A are updated based on the measured data, three-phase collective operation with higher accuracy becomes possible.

Embodiment 3 FIG.
In FIG. 1, a common closing capacitor 23 is connected to the three-phase closing coil 13, and a common opening capacitor 24 is connected to the three-phase opening coil 14. Since the voltage charged in the capacitor is not a complete constant voltage source in reality, as described in the previous embodiment, the time is set so that the timing of closing or opening of each phase coincides. When the coils of each phase are energized while being shifted, the voltage applied to the coils at the start of energization varies depending on the phase, and as a result, a difference occurs between the switching time obtained under the condition of constant applied voltage.
In the third embodiment, the difference in the switching pole time based on the difference in applied voltage to each phase coil is corrected to always achieve a highly accurate three-phase collective operation.

  FIG. 6 shows a conceptual diagram. First, the phase in which the switch (switching command) is turned on is A and the time is tA, the phase in which the switch is turned on next is B and the time is tB, the last phase in which the switch is turned on is C, and the time is tC. As shown in FIG. 6, the initial voltage applied to the coils 13 and 14 differs depending on the time when the switch is turned on. In the vacuum circuit breaker as shown in the first embodiment or the second embodiment, the operation time varies depending on the initial operation start voltage, and thus correction is necessary.

  As shown in FIG. 7, the amount of change in the closing or opening time due to the initial operation start voltage is measured in advance, and on the closing timing adjustment circuit 53 or the opening timing adjustment circuit 54 based on this value. If the closing time of the closing command switch 33 or the opening command switch 34 is adjusted, the three-phase batch operation of the vacuum circuit breaker can be performed regardless of the change in the initial voltage.

In this case, the phase sequence A, B, C and the applied voltages VA, VB, VC and the open / close pole time corrected corresponding to each applied voltage are set from the data measured in advance, and the actual operation May measure the voltages of the closing capacitor 23 and the opening capacitor 24, and may be switched on when the set applied voltage is reached.
In addition, using the switching pole time corrected in consideration of the amount of change in the applied voltage for each phase based on pre-measured data, the phase sequence and time difference for outputting the ON signal to each phase switch are obtained by calculation, and the memory As shown in the second embodiment, each time a closing operation command as a vacuum circuit breaker is issued, the data is read from the memory and an ON signal is output to each phase switch. It may be.

  As described above, in the third embodiment, by providing capacitors 23 and 24 serving as a power source in common for three phases, even if a difference occurs in the voltage applied to the coils 13 and 14 of each phase, a vacuum circuit breaker is provided. Three-phase batch operation can be realized.

Embodiment 4 FIG.
As a problem caused by providing the capacitors 23 and 24 serving as the power supply in common for the three phases, there is a difference due to the difference in the capacitance of the capacitor in addition to the difference in the applied voltage taken up in the third embodiment. In the fourth embodiment, this problem will be taken up.
That is, referring to the passage of time in FIG. 6 above, assuming that the initial capacitance of the capacitor is 3S, phase A has a capacitance of 3S from time tA to tB, and from time tB to tC. In between, it is connected in parallel with phase B, 3S / 2 capacitance, and after time tC, it will be connected in parallel with phase B and C, and is driven with S capacitance. Will be.
Phase B is driven with a capacitance of 3S / 2 from time tB to tC, and with a capacitance of S after time tC. Phase C will be driven with S capacitance after time tC.

  In the vacuum circuit breaker as shown in the first embodiment or the second embodiment, the current changes depending on the capacitance of the capacitor as the power source when viewed from the coil of each phase, and the operation time changes accordingly. Is required. As shown in FIG. 8, the amount of change in the closing or opening time due to the capacitance is measured in advance, and the closing on the closing timing adjustment circuit 53 or the opening timing adjustment circuit 54 is determined based on this value. If the time for closing the pole command switch 33 or the opening command switch 34 is adjusted, the vacuum circuit breaker can be operated in a three-phase manner regardless of the change in capacitance.

  As described above, in the fourth embodiment, by providing capacitors 23 and 24 serving as power sources in common for the three phases, even if there is a difference in the capacitance of the capacitors viewed from the coils 13 and 14 of each phase, Three-phase collective operation can be realized as a vacuum circuit breaker.

Embodiment 5 FIG.
Although not shown in the drawings, as a closing capacitor and an opening capacitor, capacitors having the same rating are provided independently for each phase, and if the same voltage is charged and used, The correction of the switching pole time accompanying the difference in applied voltage and capacitance for each phase described in the third and fourth embodiments is not necessary.

  In the first embodiment, the switching pole time of each phase is obtained from the current waveform flowing in the coil of each phase. However, for the application of the present invention, the method of measuring the switching pole time is not limited to this. Of course, for example, a method of optically capturing and measuring the movement of the electrode may be employed.

  In each modification of the present invention, the coil energization timing adjusting means includes a current measuring means for measuring a current waveform flowing in the coil of each phase, and opening / closing of each phase switch from the current waveform measured by the current measuring means. The switching timing of each phase of the three-phase AC line is determined based on the opening and closing times of each phase switch calculated by the switching timing calculation means. Since the timing of energizing the coils of each phase is adjusted for each phase so as to be within a predetermined range, the open / close pole time of each phase can be obtained easily and accurately, and the three-phase collective operation can be realized with certainty.

  In addition, when the voltage charged in the capacitor is applied to the coils of the three-phase each phase and energized, since the capacitor is provided for each phase, the power condition of the coil of each phase can be made uniform, Correction of the opening / closing pole time associated with the difference becomes unnecessary.

  In addition, when the voltage charged in the capacitor is applied to the coil of each phase of the three phases and energized, and the capacitor is common to each phase, the voltage applied from the capacitor to the coil and the opening time or closing time in advance. Since the opening / closing pole time calculation means corrects the opening time or closing time from the applied voltage value to the coil at the start of energization for each phase based on the above relation, Three-phase collective operation is realized without any problems.

  In addition, when the voltage charged in the capacitor is applied to the coils of the three-phase each phase and energized, and the capacitor is common to each phase, the capacitance of the capacitor per one phase and the opening time or closing time in advance. Based on the above relationship, the switching time calculation means corrects the opening time or closing time from the capacitance value of the capacitor at the start of energization for each phase based on the above relationship. Therefore, three-phase batch operation can be realized without any problems.

It is a figure which shows the structure of the electromagnetically operated opening / closing apparatus in Embodiment 1 of this invention. It is a figure which shows the internal structure of the opening / closing extreme time measuring apparatus 50 of FIG. It is a figure explaining the point which calculates | requires opening time from the waveform of the electric current which flows into a coil. FIG. 2 is a diagram illustrating an internal configuration of a closing timing adjustment circuit 53 of FIG. 1. It is a figure which shows the internal structure of the closing timing adjustment circuit 53A of the electromagnetically operated switchgear in Embodiment 2 of this invention. In Embodiment 3 of this invention, it is a figure explaining the change of the applied voltage to each phase coil. In Embodiment 3 of this invention, it is a figure which shows the relationship between the operation start initial voltage applied to a coil, and an operation time variation | change_quantity. In Embodiment 4 of this invention, it is a figure which shows the relationship between the electrostatic capacitance of a capacitor | condenser, and operation time variation | change_quantity.

Explanation of symbols

3 Vacuum valve, 5 Open / close contact, 5a Fixed contact, 5b Movable contact,
10 Electromagnetically operated electromagnet, 13 Closing coil, 14 Opening coil, 16 Movable iron core,
20 Drive power supply, 23 Capacitor for closing, 24 Capacitor for opening,
33 Closing command switch, 34 Opening command switch, 43 Closing current measuring instrument,
44 Opening current measuring device, 50 Opening and closing pole time measuring device, 53 Closing timing adjustment circuit,
54 Opening timing adjustment circuit.

Claims (5)

Each phase of the three-phase AC line includes a switch and an electromagnetic actuator that opens and closes the switch. The electromagnetic actuator includes a fixed iron core, a coil, and a movable iron core connected to a movable contact of the switch. In an electromagnetically operated switchgear that performs three-phase collective opening and closing of the three-phase AC line at the same three-phase timing by driving the movable iron core by energizing the coil based on a three-phase collective open / close pole command,
By adjusting the timing of energizing the coils of each phase for each phase, even if there is a variation in each phase during the switching pole time of the switch, each of the phases from the three-phase batch switching pole command And a coil energization timing adjusting means for keeping the phase switching pole operation timing of the three-phase AC line, which is the time until the phase switch operates as the switching pole, within the same predetermined range of the three phases. Operation switchgear. The coil energization timing adjusting means includes a current measuring means for measuring a current waveform flowing in the coil of each phase, and the opening and closing time of the switch of each phase from the current waveform measured by the current measuring means. A switching pole time calculating means for calculating, and based on the opening and closing times of the respective phase switches calculated by the switching pole time calculating means, each phase switching timing of the three-phase AC line is within the predetermined range. 2. The electromagnetically operated switchgear according to claim 1, wherein the timing of energizing the coils of each phase is adjusted for each of the phases so as to be within the range. When applying the voltage charged in the capacitor to the coil of each of the above three phases,
The electromagnetically operated switchgear according to claim 1 or 2, wherein the capacitor is provided for each phase. When the voltage charged in the capacitor is applied to the coils of the three-phase each phase and energized, and the capacitor is common to the phases,
The relationship between the voltage applied from the capacitor to the coil and the opening time or closing time is obtained in advance, and the opening / closing pole time calculating means is configured to perform the above-described operation at the start of energization for each phase based on the relationship. 3. The electromagnetically operated switchgear according to claim 2, wherein the opening time or closing time is corrected from a voltage value applied to the coil. When the voltage charged in the capacitor is applied to the coils of the three-phase each phase and energized, and the capacitor is common to the phases,
The relationship between the capacitance of the capacitor per phase and the opening time or closing time is obtained in advance, and the opening / closing time calculating means is configured to start energization for each phase based on the relationship. 3. The electromagnetically operated switchgear according to claim 2, wherein the opening time or closing time is corrected from the capacitance value of the capacitor.

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