Opening / closing device and opening / closing control method

Abstract

The switchgear (1) comprises a main circuit (10) that switches a three-phase system on and off with three contacts, an operating circuit (11) that performs electromagnetic operation of the contacts using an operating voltage used when operating the main circuit (10), and a control unit (2) that controls the operating circuit (11) by changing the operating voltage selected from a combination of operating voltages each time the circuit is closed, based on a control pattern in which a combination of operating voltages is set such that the amount of contact wear for each contact is statistically equalized when the opening and closing of the contacts is repeated.

Description

Technical Field

[0001] The present disclosure relates to an opening / closing device for opening and closing an electric circuit and an opening / closing control method.

Background Art

[0002] In an opening / closing device using an electromagnet excited by alternating current, the voltage phase of the exciting voltage that starts to be applied to the coil varies according to the operation timing when a closing command is input. Therefore, in the opening / closing device, the magnitude of the attractive force generated between the movable iron core and the fixed iron core changes depending on the operation timing, and the time required to reach from the open position to the closed position also varies for each operation timing. As a result, in the opening / closing device, although the closing command is input at various operation timings, the timing of closing is biased. Further, since the opening / closing device generally uses the input power supplies of the main circuit and the operation circuit from the same factory power supply, the voltage phase of the main circuit and the voltage phase of the operation circuit are synchronized.

[0003] In the opening / closing device, as described above, due to the deviation of the closing timing and the synchronization of the voltage phase of the main circuit and the voltage phase of the operation circuit, the voltage phase of the main circuit at the time of closing is biased to a specific voltage phase, so the load on the contacts of the main circuit is biased to a specific phase among the three phases (UVW phases). Therefore, the contacts of a specific phase are biased and consumed, shortening the life of the opening / closing device.

[0004] In order to avoid the contacts of a specific phase being biased and consumed, the opening / closing device of Patent Document 1 detects the consumption amount of the contacts of each phase of the main circuit and delays the voltage phase of the control voltage for electromagnetically operating the contacts according to the consumption amount of each contact, thereby equalizing the consumption amounts of the three-phase contacts.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] However, the technology described in Patent Document 1 above requires a device to detect the wear level of each contact, which has the problem of increasing the manufacturing cost of the switchgear.

[0007] This disclosure has been made in view of the above, and aims to provide a switchgear that can equalize the wear of three-phase contacts while suppressing manufacturing costs. [Means for solving the problem]

[0008] To solve the aforementioned problems and achieve the objective, the switchgear of this disclosure comprises a main circuit that switches a three-phase system on and off with three contacts, and an operating circuit that performs electromagnetic operation of the contacts using an operating voltage used when operating the main circuit. Furthermore, the switchgear of this disclosure comprises a control unit that controls the operating circuit by changing the operating voltage selected from a combination of operating voltages each time the circuit is closed, based on a control pattern in which a combination of operating voltages is set such that the amount of contact wear for each contact is statistically equalized when the opening and closing of the contacts is repeated. The control pattern is information generated based on the correspondence between the magnitude of the operating voltage and the voltage phase of the main circuit when it is closed, or information generated based on the correspondence between the voltage phase of the operating circuit when the operating voltage is output and the voltage phase of the main circuit when it is closed. [Effects of the Invention]

[0009] The switchgear described herein has the effect of equalizing the wear rate of the three-phase contacts while suppressing manufacturing costs. [Brief explanation of the drawing]

[0010] [Figure 1] Diagram showing the configuration of the switchgear according to the embodiment. [Figure 2] This figure shows the relationship between the voltage phase of the operating circuit and the voltage phase of the main circuit when the switchgear according to the embodiment is closed. [Figure 3] This figure shows the relationship between the voltage value of the operating voltage when closing the switchgear according to the embodiment and the peak of the voltage phase bias of the main circuit. [Figure 4]A flowchart showing the processing procedure of the switchgear according to the embodiment. [Figure 5] This figure shows an example of the configuration of a processing circuit when the processing circuit included in the control unit according to the embodiment is implemented using a processor and memory. [Figure 6] This figure shows an example of the configuration of a processing circuit when the processing circuit of the control unit according to the embodiment is configured with dedicated hardware. [Modes for carrying out the invention]

[0011] The opening / closing device and opening / closing control method according to embodiments of this disclosure will be described in detail below with reference to the drawings.

[0012] Embodiment. Figure 1 shows the configuration of a switchgear according to an embodiment. Switchgear 1 is a device that switches an electrical circuit on or off using an electromagnet (not shown) that is excited by alternating current. Switchgear 1 switches a three-phase system on or off with three contacts. Switchgear 1 equalizes the wear of the three-phase contacts by turning the contacts on with various operating voltages (voltage conditions).

[0013] The switchgear 1 comprises a control unit 2, a voltage detection unit 3, a part of the main circuit 10, an operation circuit 11, and a drive unit 7. The main circuit 10 has a load object 8 such as a motor, three fixed contacts 6, and three movable contacts 13. The switchgear 1 comprises the three fixed contacts 6 and three movable contacts 13 of the main circuit 10. The operation circuit 11 comprises a voltage adjustment unit 4 and a suction force generation unit 5. The connection control unit 12 is provided outside the switchgear 1 and is connected to the voltage detection unit 3. In this embodiment, one fixed contact 6 and one movable contact 13 constitute one pair (one set) of contacts, and the switchgear 1 has three sets of contacts. In the following description, a pair of one fixed contact 6 and one movable contact 13 may be referred to as a contact set. Also, depending on the operation method described later, the switchgear 1 may have a storage unit 9. Figure 1 shows the case where the switchgear 1 has a storage unit 9.

[0014] In the opening / closing device 1, the control unit 2 is connected to the voltage detection unit 3 and the voltage adjustment unit 4. Further, the voltage adjustment unit 4 is connected to the voltage detection unit 3 and the suction force generation unit 5.

[0015] In the main circuit 10, the load target 8 is connected to three connection lines L1 to L3. The connection lines L1 to L3 are connected to a power source such as a factory power source (not shown). One set of contact sets is arranged on each of the connection lines L1 to L3.

[0016] The contact set on the connection line L1 is arranged between the load target 8 and the connection point P1 on the connection line L1. The contact set on the connection line L2 is arranged between the load target 8 and the connection point P2 on the connection line L2. The contact set on the connection line L3 is arranged between the load target 8 and the factory power source.

[0017] The voltage detection unit 3 is connected to a voltage source synchronized with the factory power source of the connection lines L1 to L3. For example, the voltage detection unit 3 is connected to the connection point P1 by the connection line LX1 and to the connection point P2 by the connection line LX2. On the connection lines LX1 and LX2, a connection control unit 12 for controlling the connection between the operation circuit 11 and the connection points P1 and P2 to be on or off is arranged. Note that the voltage detection unit 3 may be provided independently of the operation circuit 11 to detect the voltage and apply a voltage to the operation circuit 11 according to the detected voltage value.

[0018] The connection control unit 12 controls the connection between the operation circuit 11 and the connection points P1 and P2 to be on or off according to an instruction from the user. When the connection control unit 12 turns on the connection, the operation circuit 11 and the factory power source are connected via the connection points P1 and P2 and the voltage detection unit 3. Each function of the connection control unit 12 is realized by a push button switch, sequence control of the switch, etc.

[0019] When the operation circuit 11 is connected to the factory power supply, the voltage detection unit 3 detects the voltage output from the factory power supply and applied to the operation circuit 11. Specifically, the voltage detection unit 3 detects the input voltage input to the circuit for opening / closing control including the operation circuit 11. When the voltage detection unit 3 detects a voltage, it transmits a signal (detection signal) indicating the detected voltage value to the control unit 2. The voltage detection unit 3 may transmit a signal (detection signal) corresponding to the detected voltage value rather than a signal indicating the detected voltage value to the control unit 2, and the control unit 2 may calculate the voltage value based on the detection signal output from the voltage detection unit 3.

[0020] The connection control unit 12 controls the connection between the operation circuit 11 and the connection points P1 and P2 to be on, and the application of voltage to the voltage detection unit 3 corresponds to the input of a closed-circuit command to the voltage detection unit 3. That is, the voltage from the factory power supply input to the voltage detection unit 3 is a closed-circuit command. The closed-circuit command is a command for closing the switching device 1.

[0021] In the switching device 1, starting from the application of a voltage as a closed-circuit command from the outside (factory power supply) to the voltage detection unit 3, the voltage detection unit 3 transmits a detection signal to the control unit 2.

[0022] The control unit 2 stores a control pattern (control pattern information) of the operation voltage used when the operation circuit 11 operates the main circuit 10. The control pattern includes various operation voltages (voltage values, phases, or both) used when the operation circuit 11 operates the main circuit 10. That is, the control pattern includes at least one of various voltage values and phases for turning on the contact set. The control pattern is created outside the switching device 1 in advance.

[0023] The storage unit 9 stores the operation voltage (voltage value, phase, or both) at the previous opening / closing sent from the control unit 2. Depending on the execution method of the control pattern of the control unit 2, the switching device 1 may or may not include the storage unit 9.

[0024] The control unit 2 controls the voltage adjustment unit 4 by sending an instruction to the voltage adjustment unit 4 to apply an operating voltage corresponding to the voltage value and phase indicated in the control pattern. In other words, the control unit 2 controls the voltage adjustment unit 4 to apply an operating voltage with the voltage value and phase of the control pattern stored in the control unit 2.

[0025] The voltage adjustment unit 4 adjusts the operating voltage based on commands transmitted from the control unit 2 and outputs the adjusted operating voltage. The voltage adjustment unit 4 then applies the adjusted operating voltage to the suction force generation unit 5.

[0026] The attractive force generating unit 5 generates the attractive force necessary for the electromagnetic operation of the contacts by adjusting the operating voltage, and drives the drive unit 7. In other words, the attractive force generating unit 5 generates an attractive force that pulls the movable core and the fixed core of the electromagnet together, and drives the drive unit 7.

[0027] The drive unit 7 is connected to an electromagnet having an iron core that is AC-excited (excited with a waveform in which AC is superimposed on DC), and is driven by the application of an operating voltage to the attractive force generation unit 5. The movable contact 13 is a contact that is driven by the application of an operating voltage to the attractive force generation unit 5. The fixed contact 6 is a fixed contact that is not driven by the application of an operating voltage to the attractive force generation unit 5.

[0028] When an operating voltage is applied to the suction force generating unit 5, the movable contact 13 moves due to the displacement of the drive unit 7, and the previously separated contact set (the fixed contact 6 and the movable contact 13) comes into contact, causing the contact set to conduct electricity and close the circuit.

[0029] Generally, even if closing commands are input to a switchgear at various operating timings, the voltage phase of the excitation voltage that begins to energize the coil differs depending on the operating timing. As a result, the voltage phase of the main circuit at the time of closing becomes biased towards a specific voltage phase, and the timing of closing becomes biased. Furthermore, the voltage phase of the main circuit and the voltage phase of the operating circuit are synchronized. Due to the bias in the timing of closing and the synchronization of the voltage phases of the main circuit and the operating circuit, a synchronous switching effect occurs in which the voltage phase of the main circuit at the time of closing becomes biased towards a specific voltage phase. This synchronous switching effect causes contacts in a specific phase of the three phases to wear out faster than other contacts, shortening the lifespan of the switchgear.

[0030] The switchgear 1 of this embodiment changes the time required to move from the open position to the closed position by changing the operating voltage so that the attractive force of the electromagnet changes, thereby arbitrarily changing the bias of the voltage phase (main circuit phase) of the main circuit 10 when closed. In other words, the switchgear 1 distributes the bias of the voltage phase of the main circuit 10, which is biased according to the operating voltage, by using various operating voltages.

[0031] Figure 2 shows the relationship between the voltage phase of the operating circuit and the voltage phase of the main circuit when the switchgear according to the embodiment is closed. In the graph shown in Figure 2, the horizontal axis represents the voltage phase of the operating circuit 11 when the operating voltage (closing signal) is output, and the vertical axis represents the voltage phase of the main circuit 10 when it is closed.

[0032] Figure 2 shows the relationship between the voltage phase of the control circuit 11 and the voltage phase of the main circuit 10 when the phase of the control voltage is changed while the switchgear 1 outputs three different voltage values ​​V1, V2, and V3 as control voltages.

[0033] As shown in Figure 2, when the voltage value is V1, the voltage phase of the main circuit 10 when closed is biased to around 150°. When the voltage value is V2, the voltage phase of the main circuit 10 when closed is biased to around 80°. When the voltage value is V3, the voltage phase of the main circuit 10 when closed is biased to around 30°. Thus, when the operating voltage value is different, the voltage phase of the main circuit 10 when closed is biased differently. In other words, the peak of the voltage phase bias of the main circuit 10 when closed differs for each operating voltage value.

[0034] In this embodiment, the peak of the voltage phase bias of the main circuit 10 when it is closed is the peak when the voltage phase distribution of the main circuit 10 when it is closed is shown as a histogram. In other words, the peak of the voltage phase bias of the main circuit 10 when it is closed is the voltage phase in the main circuit 10 when it is closed that has the greatest bias in its distribution. For example, for a voltage value V1, the peak of the voltage phase bias of the main circuit 10 when it is closed is 150°.

[0035] Here, we will explain the relationship between the voltage value of the operating voltage and the peak of the voltage phase bias for each voltage value. Figure 3 is a diagram showing the relationship between the voltage of the operating voltage when closing the switchgear according to the embodiment and the peak of the voltage phase bias of the main circuit. In the graph shown in Figure 3, the horizontal axis is the operating voltage (the voltage value applied to the operating circuit 11), and the vertical axis is the peak of the voltage phase bias of the main circuit 10 when closed. The black circles in the graph of Figure 3 indicate points plotted on the graph of Figure 3 by further increasing the voltage value of the operating voltage in Figure 2 and investigating the voltage phase of the main circuit 10 where bias occurs. The waveform of the curve shown in Figure 3 is obtained by finding an approximate curve from the values ​​of the plotted black circles.

[0036] As shown in Figure 3, for example, when the operating voltage is 185 [Vrms], the peak of the voltage phase deviation in the main circuit 10 when closed is 120°. From the graph in Figure 3, it can be seen that as the operating voltage increases, the voltage phase deviation decreases. This is because increasing the operating voltage increases the attractive force between the movable core and the fixed core, shortening the time it takes to move from the open position to the closed position. As shown in Figure 3, the operating voltage and the voltage phase deviation change continuously.

[0037] In the example shown in Figure 3, when the operating voltage is around 210 [Vrms], the peak of the voltage phase bias in the main circuit 10 becomes 0°, and as the operating voltage increases above 210 [Vrms], the peak of the bias decreases to -10° (170°), -20° (160°), and so on.

[0038] The switchgear 1 of this embodiment uses the voltage phase characteristics described in Figures 2 and 3 to turn on contact sets with various operating voltages, thereby equalizing the wear of the three-phase contact sets. In other words, in this embodiment, a control pattern for the operating voltage (voltage value, phase, or both) is calculated in advance based on the relationship between the magnitude of the operating voltage of the operating circuit 11 and the voltage phase (peak of bias) of the main circuit 10 when it is closed, or the relationship between the voltage phase at the time of the operating voltage output of the operating circuit 11 and the voltage phase of the main circuit 10 when it is closed, such that the amount of contact wear for each contact set is statistically equalized when switching is performed repeatedly. The switchgear 1 controls the operating voltage based on this control pattern and switches the contact sets open and closed. Statistical equalization in this embodiment means that when the opening and closing of the contacts is repeated for a certain period of time, the amount of contact wear for each of the three contacts is equalized.

[0039] Figure 4 is a flowchart showing the processing procedure performed by the switchgear according to the embodiment. When the connection control unit 12 controls the connection between the operation circuit 11 and connection points P1 and P2 to ON according to instructions from the user, a voltage is applied to the operation circuit 11 from an external source (factory power supply).

[0040] The switchgear 1 begins the process of closing the contact set when a voltage is applied to the operating circuit 11 from an external source. When a voltage as a closing command is applied to the operating circuit 11 from the factory power supply, the voltage detection unit 3 detects the voltage value and phase and transmits a detection signal indicating the voltage value, phase, or both to the control unit 2. As a result, the control unit 2 obtains the voltage value, phase, or both, which are the input voltage to the switchgear 1 (step S10).

[0041] When the control unit 2 obtains the voltage value, phase, or both from the voltage detection unit 3, it reads out the control pattern (step S20). Based on the control pattern and at least one of the voltage value and phase, the control unit 2 determines the operating voltage to be applied to the operating circuit 11 (step S30).

[0042] The processing from step S30 to step S40 differs depending on the method of controlling the operating voltage. First, we will explain the case where both the magnitude and phase of the operating voltage are controlled. The control unit 2 calculates the phase difference between the phase of the operating voltage, which is the control target, and the phase of the input voltage, which is the input value.

[0043] The control unit 2 converts the phase difference, which is the difference between the control target and the input value, into units of time by dividing the phase difference by 360°, which is one period of the voltage phase, and then by the frequency of the input voltage. This frequency of the input voltage may be set in advance, or it may be detected by the voltage detection unit 3. This allows the control unit 2 to calculate the waiting time, which is the time-based value of the difference between the control target and the input in terms of phase. The control unit 2 adjusts the timing of the circuit closing by waiting for the waiting time so that the phase of the operating voltage, which is the control target, matches the phase of the input voltage, which is the input value. That is, the control unit 2 adjusts the timing of the circuit closing based on the phase of the operating voltage, which is the control target, and the phase of the input voltage, which is the input value (step S31).

[0044] The control unit 2 calculates an adjustment value in the form of the difference or quotient between the magnitude of the control target operating voltage and the magnitude of the input voltage, which is the input value, and transmits the calculated adjustment value to the voltage adjustment unit 4 (step S32).

[0045] The voltage adjustment unit 4 adjusts the magnitude of the operating voltage according to the adjustment value by correcting the input voltage based on the adjustment value (step S33). In this way, the control unit 2 calculates the waiting time from the phase difference between the operating voltage and the input voltage selected based on the control pattern, and the voltage adjustment unit 4 adjusts and outputs the operating voltage after the waiting time has elapsed. This voltage adjustment method can include methods using switching, digital potentiometers, or analog circuits.

[0046] In the procedure for controlling the operating voltage from steps S31 to S33 described above, if only the magnitude of the operating voltage is to be controlled, the process is carried out by the procedures in steps S32 and S33. If only the phase of the operating voltage is to be controlled, the process is carried out by the procedure in step S31. The subsequent procedures are the same regardless of the method of controlling the operating voltage.

[0047] The voltage adjustment unit 4 applies the adjusted operating voltage to the suction force generation unit 5 (step S40). The suction force generation unit 5 generates an electromagnetic force in response to the application of the operating voltage (step S50). This causes the suction force generation unit 5 to drive the drive unit 7, which is connected to the movable contact 13 (step S60). By driving the drive unit 7, the suction force generation unit 5 pulls the drive unit 7 towards it. The displacement of the drive unit 7 causes the movable contact 13 to move, and the movable contact 13 comes into contact with the fixed contact 6. In this way, the separated contact pair comes into contact, causing the load 8 to conduct electricity to the factory power supply, and the switchgear 1 closes.

[0048] Next, the control pattern for the operating voltage set by the control pattern setter will be explained. The control pattern for controlling the magnitude of the operating voltage is defined as the range of operating voltages corresponding to a range where the voltage phase during closing has a width of 180°, in terms of the relationship between the magnitude of the operating voltage and the voltage phase during closing. In other words, the control pattern for the operating voltage is a combination of operating voltage magnitudes corresponding to combinations of voltage phases when the voltage phase of the main circuit 10 during closing is defined with a width of 180°.

[0049] Within this range, the programmer selects equally spaced voltage phases for closed circuits from within the range of closed circuit voltage phases. In other words, the combination of closed circuit voltage phases is a combination of equally spaced voltage phases. The programmer uses the operating voltage corresponding to the selected voltage phase as the operating voltage for the actual control pattern.

[0050] For example, consider the case where the user selects a voltage phase range of 60° to 240° (180° width) and sets the voltage phase interval to 30°, as shown by the dashed line in Figure 3. In this case, the phases actually used as the reference from the voltage phase range are 60°, 90°, 120°, 150°, 180°, and 210°, and the corresponding operating voltages are 195V, 189V, 185V, 180V, 177V, and 174V, respectively. In this case, for reasons to be explained later, the upper limit voltage phase of 240° and the lower limit voltage phase of 60° are equivalent conditions when the voltage phase range is selected, so the 240° voltage phase is excluded. Alternatively, the 60° voltage phase may be excluded instead of the 240° voltage phase.

[0051] The user sets one of several voltage values, such as the aforementioned 195V, as the operating voltage for the control pattern. Switchgear 1 closes with the operating voltage of the control pattern, resulting in a voltage phase bias for each operating voltage.

[0052] In the switchgear 1, the load ratio of each phase changes in accordance with the voltage phase of the main circuit 10, which is the contact phase. However, due to the electrical symmetry of three-phase AC, the load ratio of each phase changes repeatedly in the same way with a 180° period. Therefore, even if the load ratio of each phase is not equal when viewed with only one closing command, the load ratio of each phase is statistically averaged by repeatedly closing the circuit using a control pattern that results in equally spaced voltage phases within a 180° period. Consequently, in the switchgear 1, the load on the contact sets of each phase does not become biased towards a particular phase, contact wear is statistically averaged, and the lifespan is extended.

[0053] Here, we will explain the electrical symmetry of three-phase alternating current. In three-phase alternating current, each phase is symmetrical with a phase interval of 120°. However, in this embodiment, the contact load is to be made uniform, so the direction of current flow is irrelevant. Therefore, in this embodiment, there is no need to consider the positive and negative signs, and only the magnitude of the electricity needs to be considered. In this case, the symmetry in each phase of the three phases becomes a 60° interval instead of a 120° interval, and one period can be considered to be 180° instead of 360°.

[0054] Thus, since one period is 180°, as mentioned above, a voltage phase of 240° and a voltage phase of 60° are equivalent conditions, and a voltage phase of 240° is excluded. Furthermore, regarding the control pattern of the operating voltage, by utilizing the fact that the symmetry of each phase of the three phases is at 60° intervals, the voltage phase does not have to be within the range of 180°. For example, it is possible to select any number of sets of phases at 60° intervals so that the contact load of the three phases is equal, such as a set of 0°, 60°, and 120° (in the range of 0° to 120°) and a set of 20°, 80°, and 140° (in the range of 20° to 140°), and set the corresponding voltages as the voltage control pattern.

[0055] Furthermore, in the control pattern stored by the control unit 2, information on the number of times (frequency) the switch is opened or closed for each voltage value of the operating voltage may be added to set more detailed control conditions. In other words, in the control pattern, the number of uses for each operating voltage may be set so that the number of occurrences of the operating voltage is made uniform. As a result, even if the number of operating voltage settings corresponding to the peak bias differs in the control pattern, the switchgear 1 will select the operating voltage so that the number of occurrences of the operating voltage is made uniform, thereby making the contact load uniform.

[0056] Furthermore, the control pattern may include a voltage phase range exceeding 180°, such as 0° to 210°, and a range of operating voltages corresponding to this voltage phase. In this case, the control pattern corrects the frequency of use (number of switches) of the operating voltages corresponding to the voltage phase range of 180° or more. Note that the control pattern does not necessarily need to include correction information. In this case, the switchgear 1 corrects the frequency of use of the operating voltages.

[0057] For example, when setting the control pattern, if a voltage phase range of 0° to 210° is selected, and the voltage phase interval is 60°, then there are no selectable voltage phases beyond 180°, and this does not affect the frequency of use of the operating voltage. Here, let's consider the case where 10° is set as the voltage phase interval that affects the frequency of use of the operating voltage. In this case, the selectable voltage phases are 0°, 10°, ..., 180°, 190°, and 200°.

[0058] Here, voltage phases greater than 180° are equivalent to voltage phases from 0° to 30° due to the symmetry of three-phase AC, and therefore overlap with the 0° to 30° voltage phase range. For this reason, the voltage phase range from 0° to 30° is used twice as frequently as the voltage phase range from 30° to 180°. Therefore, the control pattern is set so that when the operating voltage corresponding to the voltage phases from 0° to 30° and 180° to 210° is used once each, the operating voltage corresponding to the voltage phase from 30° to 180° is used twice each. This allows the switchgear 1 to compensate for the difference in the frequency of operating voltage use and perform switching under uniform operating conditions.

[0059] Furthermore, the control pattern may also include a voltage phase range narrower than 180°, such as 0° to 150°, and a corresponding operating voltage range. In this case, the equalization effect will decrease depending on the phase range because some phase ranges cannot be used, but a certain effect can be obtained by correcting the frequency of use of the operating voltage.

[0060] Regarding the setting of the control pattern for the operating voltage, within the range of the control pattern for the operating voltage, the setter can select operating voltage values ​​that are at arbitrary intervals from within the range of operating voltage values ​​corresponding to the voltage phase range when the circuit is closed, and set a combination of each operating voltage value and frequency as a control pattern so that the load on the three phase contacts is evenly distributed.

[0061] For example, consider the case where the user selects a voltage phase range of 60° to 240° (180° width) as shown by the dashed line in Figure 3, and sets the voltage intervals to an equal 5V. Also, for the sake of simplicity, assume that a load is applied to the U-phase contacts from 0° to 60°, the V-phase contacts from 60° to 120°, and the W-phase contacts from 120° to 180°, and that the phase that appears most frequently when switching at the voltage value used will be the one that occurs. In this case, since the voltage phase range is from 60° to 240°, the operating voltage range will be from 195V corresponding to 60° to 174V corresponding to 210°. Within this voltage phase range, the operating voltages actually used will be 195V, 190V, 185V, 180V, and 175V. When each of these operating voltages is used once to switch the power on, the load is applied to the U-phase, V-phase, V-phase, W-phase, and W-phase in the order of the operating voltages. As a result, the U-phase is loaded once, while the V-phase and W-phase are loaded twice each, leading to uneven wear. Therefore, by setting the control pattern to use only the 195V voltage, which loads the U-phase, twice as frequently as the other voltages, all three phases are loaded twice each when the control pattern is used, allowing for even switching with equal wear.

[0062] Next, the control pattern for controlling the phase of the operating voltage will be described. The control pattern is defined as the relationship between the voltage phase of the operating circuit when the operating voltage is output and the voltage phase of the main circuit when it is closed, at a specific voltage value of the operating voltage. For example, the voltage phase of the main circuit when it is closed is defined as a range with a width of 180°. In other words, the control pattern for the phase of the operating voltage is the combination of voltage phases of the operating circuit when the operating voltage is output that corresponds to the combination of voltage phases when the voltage phase of the main circuit 10 when it is closed is defined with a width of 180°.

[0063] Within this range, the setter selects voltage phases of the main circuit during closing that are equally spaced from within the range of voltage phases of the main circuit during closing. In other words, the combination of voltage phases of the main circuit during closing is a combination of voltage phases that are changed at equal intervals. The setter sets the voltage phase of the control circuit at the time of control voltage output that corresponds to the selected voltage phase of the main circuit during closing as the phase of the control voltage used in the actual control pattern. When selecting the voltage phase of the control circuit at the time of control voltage output that corresponds to the selected voltage phase of the main circuit during closing, the magnitude of the control voltage is also taken into consideration when making the selection, as the relationship between the corresponding phases differs depending on the magnitude of the control voltage.

[0064] For example, consider the case shown in Figure 2 where the user selects a voltage value V3 and a voltage phase range of 0° to 180° during closing, and sets the voltage phase interval to 30°. In this case, the voltage phases of the main circuit during closing, which are actually used as the reference, will be 0°, 30°, 60°, 90°, 120°, and 150°, and the corresponding voltage phases of the control circuit when the control voltage is output will be 123°, 162°, 50°, 72°, 88°, and 105°, respectively.

[0065] The user sets one of several voltage phases, such as the aforementioned 123°, as the phase of the operating voltage set in the control pattern. Switchgear 1 closes with an even voltage phase by applying the operating voltage with the operating voltage phase of the control pattern. Therefore, in switchgear 1, the load on the contact sets of each phase does not become biased towards a particular phase, and contact wear is statistically averaged, extending the lifespan.

[0066] Furthermore, regarding the control pattern of the operating voltage phase, by utilizing the fact that the symmetry of each phase of the three phases is spaced at 60° intervals, even if the voltage phase of the main circuit during closing is not within a 180° range, it is possible to select any number of phase sets at 60° intervals that equalize the contact load of the three phases and use the voltage phase of the operating circuit during the corresponding operating voltage output as the control pattern. For example, a set of 0°, 60°, and 120° (in the range of 0° to 120°) and a set of 20°, 80°, and 140° (in the range of 20° to 140°) may be selected as the voltage phase of the main circuit during closing.

[0067] Furthermore, due to constraints on the time required from the input of a closing command to the actual closing of the circuit, the waiting time must be less than or equal to half a cycle (180°) of the input voltage. In other words, a control pattern may be set where the phase that can be adjusted by the waiting time is narrower than 180°. In this case, although the equalization effect will decrease depending on the range due to the inability to use a portion of the phase range, a certain effect can still be obtained.

[0068] Furthermore, regarding the control pattern of the operating voltage, it is also possible to control it by combining both the magnitude and phase of the operating voltage. This control pattern combines the relationship between the magnitude of the operating voltage and the voltage phase when the circuit is closed, and the relationship between the voltage phase of the operating circuit when the operating voltage is output and the voltage phase of the main circuit when the circuit is closed, for example, to set the range in which the voltage phase when the circuit is closed has a width of 180°. In other words, the control pattern of the combination of magnitude and phase of the operating voltage is any combination of magnitude and phase of the operating voltage.

[0069] Another control pattern involves controlling the magnitude and phase of the operating voltage, taking into account the phase of the input voltage detected by the voltage detection unit 3. In this method, an arbitrary number of candidate voltage phases of the main circuit at the target closing time and the magnitude of the operating voltage to be used are determined in advance. Next, for each of the target voltage phases of the main circuit at the target closing time, the magnitude of the operating voltage to be used is determined based on the phase of the input voltage detected by the voltage detection unit 3. By controlling the phase at the magnitude of that operating voltage and performing the closing operation, the load on each phase contact set is distributed. This method has the advantage of equalizing contact wear even when it is desired to shorten the time required for the closing operation or when it is desired to limit the range of the operating voltage magnitude due to the specifications or design intent of the attraction force generation unit 5.

[0070] For example, the target voltage phase of the main circuit when closed is set to 0°, 60°, and 120°, and the candidate magnitudes of the operating voltages to be used are V1, V2, and V3. In Figure 2, if the target is to set the voltage phase of the main circuit when closed to 0°, the voltage phases of the operating circuit when the operating voltage is output for each voltage value are V1: 50°, V2: 90°, and V3: 123°. Under these conditions, by waiting for a waiting time, the control unit 2 controls the voltage phase of the operating circuit when the operating voltage is output by delaying the phase of the input voltage detected by the voltage detection unit 3. To minimize the waiting time, the operating voltage magnitudes are set to V1 when the input voltage phase is 0° to 50° and 123° to 180°, V2 when it is 50° to 90°, and V3 when it is 90° to 123°. Similarly, if the goal is to achieve a 60° voltage phase in the main circuit when closed, the operating voltage magnitudes are set to V1 when the input voltage phase is 50° to 84°, V2 when it is 84° to 132°, and V3 when it is 132° to 180° and 0° to 50°. Also, if the goal is to achieve a 120° voltage phase in the main circuit when closed, the operating voltage magnitudes are set to V1 when the input voltage phase is 78° to 108°, V2 when it is 108° to 180° and 0° to 57°, and V3 when it is 57° to 78°. The control unit 2 uses these conditions as a control pattern and controls the magnitude and phase of the operating voltage according to the phase detected by the voltage detection unit 3 and the target voltage phase of the main circuit when closed.

[0071] In this embodiment, the control pattern registered in the control unit 2 is pre-generated by the user based on the relationship between the magnitude of the operating voltage and the voltage phase of the main circuit 10 when closed, or the relationship between the voltage phase of the operating circuit 11 when the operating voltage is output and the voltage phase of the main circuit 10 when closed. The switchgear 1 is tested in the manufacturing process, such as during shipment inspection, and the control pattern may be modified or newly generated based on the test results. This allows the switchgear 1 to perform switching using a control pattern appropriate to its manufacturing state, thereby further extending its lifespan.

[0072] Furthermore, the switchgear 1 has a defined range of usable input voltages, and the user applies any voltage value within that range as the input voltage. To accommodate this situation, the control pattern may have multiple operating voltage ranges set. In this case, the switchgear 1 selects a usable operating voltage range from among the multiple operating voltage ranges set in the control pattern.

[0073] Thus, the switchgear 1 of this embodiment can statistically average contact wear by controlling the operating voltage according to a pre-generated control pattern of operating voltages. Specifically, the switchgear 1 of this embodiment can statistically average contact wear by controlling the operating circuit by changing the operating voltage selected from a combination of operating voltages each time the circuit is closed, based on a control pattern in which a combination of operating voltages is set such that the amount of contact wear for each contact is statistically equalized when the opening and closing of the contacts is repeated. Furthermore, since the switchgear 1 can average contact wear without using a device to detect the amount of wear for each contact set, it can suppress an increase in manufacturing costs.

[0074] Furthermore, since the switchgear 1 averages out contact wear by controlling the operating voltage, contact wear can be averaged even in the case of a switchgear 1 with a control method that cannot control the voltage phase of the operating circuit 11.

[0075] The switchgear 1 sets the voltage phase interval to 30° within the range of a voltage phase of 60° to 240° relative to the control pattern of the operating voltage. This voltage phase interval may be set in advance in the control pattern, or the switchgear 1 may set it according to instructions from the user.

[0076] Here, we consider the case where the switchgear 1 actually uses voltage phases of 60°, 90°, 120°, 150°, 180°, and 210°, and the operating voltages are 195V, 189V, 185V, 180V, 177V, and 174V.

[0077] In this case, the control unit 2 can equalize the wear on the three-phase contact set by randomly extracting the operating voltage set in the control pattern and applying it from the voltage adjustment unit 4 to the suction force generation unit 5. The control unit 2 randomly extracts and applies the operating voltage from the set operating voltage, for example, 195V → 180V → 177V → 189V → ...

[0078] Furthermore, when the control unit 2 reads the operating voltage from the control pattern, it may not randomly extract the operating voltage, but rather extract and apply the operating voltage according to the order set in the control pattern, for example, 195V → 189V → 185V... In this case as well, the switchgear 1 can obtain the same effect as when the operating voltage is randomly extracted.

[0079] When the control unit 2 reads out the operating voltages in the order set in the control pattern, it is desirable to store in the storage unit 9 which order of the operating voltages in the control pattern was used in the most recent power-on closing operation (when the switchgear 1 is turned on) in order to use the set operating voltages evenly.

[0080] In this case, when the power to the switchgear 1 is turned on again (the next time the power is turned on), the control unit 2 reads out the control pattern of the operating voltage and the stored operating voltage from the memory unit 9 (the operating voltage at the most recent power-on until the power is turned on again). In other words, when the next closing operation is performed, the control unit 2 reads out the control pattern of the operating voltage and the stored operating voltage.

[0081] Then, the control unit 2 restarts the closing operation using the next sequence of operating voltages that it has stored. In other words, the control unit 2 restarts the closing operation using the next sequence of operating voltages that was used when the power was last turned on.

[0082] Alternatively, the control unit 2 may count the number of times each operating voltage set in the control pattern is used and store it in the storage unit 9, and determine the operating voltage to be used the next time the power is turned on based on the count value.

[0083] The control unit 2 determines the operating voltage to be used the next time the power is turned on, for example, based on the number of times the operating voltage is set in the control pattern and the count value for each operating voltage read from the storage unit 9. For example, if each operating voltage is set once in the control pattern, the control unit 2 selects the operating voltage with the smallest count value to be used the next time the power is turned on. If the count value for each operating voltage is the same for all operating voltages, the control unit 2 may select any of the operating voltages set in the control pattern. After determining the operating voltage, the control unit 2 updates the count value of the operating voltage stored in the storage unit 9.

[0084] Furthermore, in the control pattern, if a voltage phase range exceeding 180°, such as 0° to 210°, is set, and the frequency of use of the operating voltage corresponding to the voltage phase range of 180° or more is corrected, the control unit 2 determines the operating voltage to be used the next time the power is turned on, based on the corrected frequency of use and the count value.

[0085] Next, the hardware configuration of the control unit 2 will be described. The control unit 2 is implemented by a processing circuit. The processing circuit may be a processor and memory that execute a program stored in memory, or it may be dedicated hardware.

[0086] Figure 5 is a diagram showing an example of the configuration of a processing circuit when the processing circuit provided in the control unit according to the embodiment is realized with a processor and memory. The processing circuit 90 shown in Figure 5 includes a processor 91 and memory 92. When the processing circuit 90 is composed of a processor 91 and memory 92, each function of the processing circuit 90 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a control program and stored in memory 92. In the processing circuit 90, each function is realized by the processor 91 reading and executing the control program stored in memory 92. In other words, the processing circuit 90 includes memory 92 for storing a control program that will result in the processing of the control unit 2 being executed. This control program can also be said to be a program that causes the control unit 2 to execute each function realized by the processing circuit 90. This control program may be provided on a computer-readable recording medium on which the control program is recorded, or it may be provided by other means such as a communication medium.

[0087] In the case of the control unit 2 of this embodiment, the control program can also be described as a program that causes the control unit 2 to execute the processes of steps S10 to S30, S31, or steps S10 to S30, S32, S33 in Figure 4. The control program executed by the control unit 2 has a modular configuration that includes the functions of the control unit 2, and the functions of the control unit 2 are loaded into the main memory and generated in the main memory.

[0088] Here, the processor 91 can be, for example, a CPU (Central Processing Unit), processing unit, arithmetic unit, microprocessor, or DSP (Digital Signal Processor). The memory 92 can be, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), or EEPROM (Electrically EPROM).

[0089] Figure 6 shows an example of the configuration of a processing circuit when the processing circuit of the control unit according to the embodiment is configured with dedicated hardware. The processing circuit 93 shown in Figure 6 can be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The processing circuit 93 may be partially implemented with dedicated hardware and partially implemented with software or firmware. In this way, the processing circuit 93 can realize each of the above functions with dedicated hardware, software, firmware, or a combination thereof.

[0090] As described above, the switchgear 1 of this embodiment stores a control pattern in which a combination of operating voltages is set such that the amount of contact wear is statistically equalized when the opening and closing of the contact set is repeated. This control pattern is information generated based on the correspondence between the magnitude of the operating voltage and the voltage phase of the main circuit 10 when the circuit is closed, or the correspondence between the voltage phase when the operating voltage is output and the voltage phase of the main circuit 10 when the circuit is closed. The switchgear 1 controls the operating circuit 11 by changing the operating voltage selected from the combination of operating voltages each time the circuit is closed.

[0091] As a result, the switchgear 1 can distribute the voltage phase of the main circuit 10 when closed to various voltage phases without using a device to detect contact wear, thereby equalizing the wear of the three-phase contacts. Therefore, the switchgear 1 can equalize the wear of the three-phase contact set while suppressing manufacturing costs. As a result, the lifespan of the switchgear 1 is extended.

[0092] Furthermore, since the switchgear 1 randomly extracts an operating voltage from a determined control pattern and applies it from the voltage adjustment unit 4 to the suction force generation unit 5, the wear rate of the three-phase contact set can be equalized.

[0093] Furthermore, the switchgear 1 reads the operating voltages sequentially from the determined control pattern and applies them from the voltage adjustment unit 4 to the suction force generation unit 5, thereby equalizing the wear on the three-phase contact set. Also, the switchgear 1 restarts the closing operation using the operating voltage that follows the operating voltage used when the power was last turned on, thereby equalizing the wear on the three-phase contact set.

[0094] The configurations shown in the above embodiments are merely examples, and can be combined with other known technologies. It is also possible to omit or modify parts of the configuration without departing from the gist of the invention. [Explanation of symbols]

[0095] 1 Switching device, 2 Control unit, 3 Voltage detection unit, 4 Voltage adjustment unit, 5 Suction force generation unit, 6 Fixed contact, 7 Drive unit, 8 Load target, 9 Memory unit, 10 Main circuit, 11 Operation circuit, 12 Connection control unit, 13 Movable contact, 90, 93 Processing circuit, 91 Processor, 92 Memory, L1~L3, LX1, LX2 Connection lines, P1, P2 Connection points, V1~V3 Voltage values.

Claims

1. The main circuit switches the three-phase system on and off with three contacts, An operating circuit that performs electromagnetic operation of the contacts by an operating voltage used when operating the main circuit, A control unit controls the operating circuit by changing the selected operating voltage each time the circuit is closed, based on a control pattern in which a combination of operating voltages is set such that the contact wear amount for each of the contacts is statistically equalized when the opening and closing of the contacts is repeated. Equipped with, The aforementioned control pattern is This information is generated based on the correspondence between the magnitude of the operating voltage and the voltage phase of the main circuit when it is closed, or based on the correspondence between the voltage phase of the operating circuit when the operating voltage is output and the voltage phase of the main circuit when it is closed. A switching device characterized by the following features.

2. The aforementioned operating circuit is A voltage adjustment unit that adjusts and outputs the operating voltage so that it becomes the operating voltage selected by the control unit, When the operating voltage adjusted by the voltage adjustment unit is input, the attractive force generating unit generates the attractive force necessary for the electromagnetic operation using the operating voltage, The opening and closing device according to claim 1, characterized by comprising the above.

3. A voltage detection unit that detects the input voltage input to the switching control circuit including the aforementioned operating circuit, Furthermore, The control unit, The adjustment value for the input voltage is calculated from the difference between the input voltage detected by the voltage detection unit and the operating voltage selected based on the control pattern. The voltage adjustment unit is The operating voltage is adjusted and output by correcting the input voltage based on the adjustment value. The opening and closing device according to feature 2.

4. The control unit, The waiting time is calculated from the phase difference between the operating voltage selected based on the control pattern and the input voltage. The voltage adjustment unit is After the aforementioned waiting time has elapsed, the operating voltage is adjusted and output. The opening and closing device according to claim 3.

5. The control pattern is a combination of operating voltages corresponding to the combination of voltage phases when the voltage phase is defined with a width of 180°. The opening and closing device according to feature 1.

6. The aforementioned voltage phase combination is a combination of the aforementioned voltage phases that are changed at equal intervals. The opening and closing device according to feature 5.

7. The aforementioned combination of operating voltages is a combination of operating voltages that are changed at arbitrary intervals, and a usage frequency is set for each of the aforementioned operating voltages such that the contact wear is statistically equalized. The opening and closing device according to feature 5.

8. The control unit randomly extracts the operation voltage from the control pattern and controls the operation circuit using the extracted operation voltage. The opening and closing device according to feature 1.

9. The control unit, The operation voltages are extracted sequentially from the control pattern, and the operation circuit is controlled using the extracted operation voltages. The memory unit stores which sequence of operating voltages from the control pattern was used in the latest closed-circuit operation. During the next closing operation, the control circuit is controlled using the next sequence of operating voltages that have been stored. The opening and closing device according to any one of claims 1 to 8.

10. The control unit counts the number of times the operating voltage set in the control pattern has been used for each operating voltage, and selects the operating voltage to be used during the next closing operation based on the count value and the number of times the operating voltage set in the control pattern has been used. The opening and closing device according to any one of claims 1 to 8.

11. A switching device comprising a main circuit that switches a three-phase system on and off using three contacts, and an operating circuit that performs electromagnetic operation of the contacts using an operating voltage used when operating the main circuit, wherein the switching control method for the contacts is as follows: The switching device includes a control step of controlling the operating circuit by changing the operating voltage selected from the combination of operating voltages each time the circuit is closed, based on a control pattern in which the contact wear amount for each of the contacts is statistically equalized when the opening and closing of the contacts is repeated. The aforementioned control pattern is This information is generated based on the correspondence between the magnitude of the operating voltage and the voltage phase of the main circuit when it is closed, or based on the correspondence between the voltage phase of the operating circuit when the operating voltage is output and the voltage phase of the main circuit when it is closed. A method for controlling opening and closing, characterized by the above.

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