KR102175619B1 - Vacuum pump and operation method of the vacuum pump - Google Patents

Abstract

An object of the present invention is to provide a vacuum pump capable of reducing the frequency of operation stop due to occurrence of an error.
The vacuum pump of the present invention includes a pump module 1 for exhausting gas, a motor 2 for driving the pump module 1, and an inverter device 5 for supplying AC power of a variable frequency to the motor 2 Wow, a control device 7 for controlling the inverter device 5 is provided. The inverter device 5 stops its operation when an error due to overvoltage or overcurrent occurs, and the control device 7 stops the inverter device 5 if the occurrence of the error satisfies a predetermined condition. Restart.

Description

Vacuum pump and its operation method {VACUUM PUMP AND OPERATION METHOD OF THE VACUUM PUMP}

The present invention relates to a vacuum pump that sucks gas from a sealed container such as a vacuum chamber, and more particularly, to a vacuum pump having an inverter device with a protection function for avoiding failure due to overvoltage and/or overcurrent.

Dry vacuum pumps are widely used as manufacturing equipment for semiconductor devices. In the process of manufacturing a semiconductor device, there is a process of processing a product in a vacuum space, and a dry vacuum pump is used to form the vacuum space.

A dry vacuum pump generally performs motor control with an inverter device for the purpose of outputting a desired torque or changing an operation speed in order to save energy or control the pressure in a vacuum space. Some inverter devices have a protection function to protect themselves in order to avoid failures caused by errors such as overvoltage and/or overcurrent. In this type of inverter device, when an error is detected, a protection function is activated to stop its operation.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-127107 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-89428

However, if the dry vacuum pump suddenly stops operating during the production of a semiconductor device, the pressure in the vacuum space rises, causing damage to the product (semiconductor device) being produced, resulting in defective products.

Accordingly, an object of the present invention is to provide a vacuum pump capable of reducing the frequency of operation stop due to occurrence of an error and a method of operating the same.

In order to achieve the above object, a first aspect of the present invention is a pump module for exhausting gas, a motor for driving the pump module, an inverter device for supplying AC power of a variable frequency to the motor, and the inverter. A control device for controlling the device is provided, and the inverter device stops its operation when an error due to overvoltage or overcurrent occurs, and the control device ensures that the occurrence of the error satisfies a predetermined condition. If there is, it is a vacuum pump characterized in that the inverter device is restarted.

A second aspect of the present invention includes a pump module that exhausts gas, a motor that drives the pump module, an inverter device that supplies AC power of a variable frequency to the motor, and a control device that controls the inverter device. The inverter device stops its operation when an error due to overvoltage or overcurrent occurs, and the control device transmits an error cancellation signal to the inverter device for releasing an error occurring within a predetermined period. And, the inverter device is a vacuum pump characterized in that, upon receiving the error cancellation signal, does not stop its own operation when the error occurs within the predetermined period.

A third aspect of the present invention includes a pump module that exhausts gas, a motor that drives the pump module, an inverter device that supplies AC power of a variable frequency to the motor, and a control device that controls the inverter device. The inverter device, when an error occurs, stops its operation, and the control device restarts the inverter device after the inverter device stops operating, and the number of errors occurring within a set time is predetermined. When the threshold value of is reached, the inverter device is not restarted.

A fourth aspect of the present invention includes a pump module that exhausts gas, a motor that drives the pump module, an inverter device that supplies AC power of a variable frequency to the motor, and a control device that controls the inverter device. A method of operating a vacuum pump, characterized in that when an error due to overvoltage or overcurrent occurs, the operation of the inverter device is stopped, and when the occurrence of the error satisfies a predetermined condition, the inverter device is restarted. This is how the vacuum pump operates.

A fifth aspect of the present invention includes a pump module that exhausts gas, a motor that drives the pump module, an inverter device that supplies AC power of a variable frequency to the motor, and a control device that controls the inverter device. As a method of operating a vacuum pump, when an error due to overvoltage or overcurrent occurs, the operation of the inverter device is stopped, and an error cancellation signal for releasing an error occurring within a predetermined period is transmitted to the inverter device, In the case where the error occurs within the predetermined period, the operation of the inverter device is not stopped.

A sixth aspect of the present invention includes a pump module that exhausts gas, a motor that drives the pump module, an inverter device that supplies AC power of a variable frequency to the motor, and a control device that controls the inverter device. As an operation method of one vacuum pump, when an error occurs, the operation of the inverter device is stopped, the inverter device is restarted after the operation of the inverter device is stopped, and the number of errors occurring within a set time is a predetermined threshold. When the value is reached, the inverter device is not restarted.

According to the first and fourth aspects of the present invention, when an error occurs under a predetermined condition, the inverter device is restarted. This predetermined condition is a condition for generating an error in which it is expected that the inverter device does not fail even if the inverter device continues to operate. With such error monitoring control, the frequency of stopping the operation of the pump due to occurrence of an error can be reduced.

According to the second and fifth aspects of the present invention, when an error occurs within a predetermined period, the error is automatically canceled, and the inverter device is not stopped. With such error monitoring control, the frequency of stopping the operation of the pump due to occurrence of an error can be reduced.

According to the third and sixth aspects of the present invention, even if the operation of the inverter device is stopped due to occurrence of an error, as long as the number of errors occurring within the set time does not reach a predetermined threshold value, the inverter device is immediately restarted. With such error monitoring control, the frequency of stopping the operation of the pump due to occurrence of an error can be reduced. Further, since any one of the plurality of timers starts time measurement every time an error occurs, the control device can quickly and reliably detect that the error has occurred at a high frequency.

1 is a schematic diagram showing a vacuum pump according to an embodiment of the present invention.
2 is a schematic diagram of an inverter device.
3 is a graph showing a change in the rotational speed of the motor when an error occurs when the motor is idle.
4 is a graph showing a change in the rotational speed of the motor when an error occurs when the inverter device decelerates the motor according to a command from the control device.
5 is a diagram for explaining the operation of a counter for counting the number of errors and a timer for measuring a monitoring time.
6 is a graph illustrating that the inverter device is in an error canceling mode in a predetermined period.
7 is a schematic diagram showing a vacuum pump according to another embodiment of the present invention.
8 is a time chart for explaining the operation of a timer when an error occurs with a low frequency.
9 is a time chart for explaining the operation of a timer when an error occurs with a high frequency.
Fig. 10 is a time chart for explaining a method of determining whether or not the number of errors occurring within a set time reaches a predetermined threshold value using one timer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a schematic diagram showing a vacuum pump according to an embodiment of the present invention. As shown in Fig. 1, the vacuum pump supplies a pump module 1 that exhausts gas, a motor 2 that drives the pump module 1, and an AC power of a variable frequency to the motor 2 An inverter device 5 is provided and a control device 7 that controls the inverter device 5 is provided.

The pump module 1 is connected to a sealed container 8 such as a vacuum chamber, and sucks gas in the sealed container 8 to form a vacuum in the sealed container 8. As the pump module 1, a dry pump module that does not use oil is formed in a gas flow path formed therein. A vacuum pump equipped with such a dry pump module is generally called a dry vacuum pump, and is widely used in the manufacture of semiconductor devices.

2 is a schematic diagram of the inverter device 5. As shown in Fig. 2, the inverter device 5 includes a converter unit 11, a smoothing capacitor 15, an inverter unit 12, a gate driver 13, and an inverter control unit 16. The converter unit 11 has a rectifying circuit therein, and is configured to convert three-phase AC power supplied from the power supply source 9 into DC power. The smoothing capacitor 15 is provided to smooth the converted DC power.

The inverter unit 12 has a switching element such as an IGBT (insulated gate bipolar transistor), and generates three-phase AC power from the smoothed DC power. The gate driver 13 generates a gate drive signal for opening and closing each switching element of the inverter unit 12. The switching element of the inverter unit 12 is driven according to a gate drive signal from the gate driver 13, whereby the inverter unit 12 outputs AC power of a variable frequency.

The current measuring device 20 measures the three-phase current output from the inverter unit 12 and sends the measured value of the three-phase current to the inverter control unit 16. The inverter control unit 16 controls the AC power output from the inverter unit 12 based on the measured value sent from the current measuring device 20 and the speed command value sent from the control device 7. That is, the inverter control unit 16 receives the speed command value from an upper-level pump controller (not shown), and generates a PWM signal based on the measured value of the three-phase current. This PWM signal is sent to the gate driver 13. The gate driver 13 generates a gate drive signal for driving the switching element of the inverter unit 12 based on the PWM signal. The switching element of the inverter unit 12 is driven according to a gate drive signal from the gate driver 13, whereby the inverter unit 12 outputs AC power of a variable frequency to the motor 2.

The inverter device 5 has a protection function for protecting itself from failure when an error such as overvoltage or overcurrent occurs. More specifically, when an error occurs, the inverter device 5 is configured to stop its operation. Errors are largely divided into an overvoltage error (ie, an excessive voltage is applied to the inverter device 5) and an overcurrent error (ie, an excessive current flows through the inverter device 5).

When the DC power input to the converter unit 11 increases, there is a fear that the smoothing capacitor 15 inside the inverter device 5 and each switching element of the inverter unit 12 may be destroyed. Thus, the inverter device 5 is configured to monitor the DC voltage of the converter unit 11 and, when the DC voltage is equal to or greater than a preset value, the inverter device 5 to stop its operation.

As a cause of the increase in the DC voltage of the converter unit 11, an abnormality in the power supply source 9 and a hunting in the inverter control are considered. Hereinafter, an overvoltage error caused by an abnormality in the power supply source 9 is referred to as error 1, and an overvoltage error caused by hunting in the inverter control is referred to as error 2.

Error 1 is caused by an abnormality in the power supply source 9 supplying AC power to the inverter device 5. Error 1 can be caused by several causes. When the error 1 occurs, the input voltage to the inverter device 5 increases, and there is a fear that the inverter device 5 may fail. Therefore, in this case, the inverter device 5 immediately stops its operation.

Error 2 is likely to occur when, after a momentary power failure, the motor 2 and the pump module 1 which are rotating only by inertia force (that is, free running) are restarted. When a momentary power failure occurs, the power output of the inverter device 5 automatically stops (that is, since power is not input, the inverter device 5 cannot output power). Since the temporal length of the instantaneous power failure is usually within 1 second, during the instantaneous power failure, the motor 2 continues to rotate in inertia, but the rotational speed of the motor 2 gradually decreases due to loss of bearings or the like.

When the power is restored, the inverter device 5 measures the rotational speed of the current motor 2 that is free running, and the inverter device 5 measures AC power having a frequency synchronized with the rotational speed of the motor 2 Start the output of. At this time, when the inverter device 5 outputs AC power having a frequency lower than the frequency corresponding to the rotational speed of the motor 2, the inverter device 5 actively decelerates the motor 2, and the motor 2 The power of is returned to the inverter device 5 as regenerative energy. As a result, the voltage in the inverter device 5 rises, resulting in an overvoltage.

When the power failure continues for a certain long time, the motor 2 stops completely. Accordingly, the operation of starting the inverter device 5 after a prolonged power failure is not changed in any way from the normal starting operation, and in this case, the above-described error does not occur.

Error 2 is likely to occur even when the inverter device 5 decelerates the motor 2 in response to a command from the control device 7. For example, when the vacuum pump shifts from the normal operation mode to the idle operation mode, the control device 7 instructs the inverter device 5 to lower the rotational speed of the motor 2. When the rotational speed of the motor 2 is actively lowered in this way, the power of the motor 2 may return to the inverter device 5 as regenerative energy. As a result, the voltage in the inverter device 5 rises, and an overvoltage may occur.

In addition to overvoltage, overcurrent can also cause failure of the inverter device 5. That is, when a large current flows through the inverter device 5, there is a fear that the switching element inside the inverter device 5 may be destroyed. Thus, the inverter device 5 is configured to monitor the output current of the inverter unit 12, and when the output current is equal to or greater than a preset value, the inverter device 5 is configured to stop its operation.

As the cause of the overcurrent, hunting of inverter control and failure of the motor 2 are considered. Hereinafter, the overcurrent error caused by the hunting of the inverter control is referred to as error 3, and the overcurrent error caused by the failure of the motor 2 is referred to as error 4.

Error 3 is similar to error 2, after a momentary power failure, when the motor 2 is restarted with only inertia force, or in response to a command from the control device 7, the inverter device 5 causes the motor ( It is likely to occur when 2) is slowed down. For example, when the inverter device 5 is restarted after a momentary power failure, if the frequency of the AC power output from the inverter device 5 is significantly different from the actual rotation speed of the motor 2, overcurrent due to hunting of the inverter control Flows. In particular, when sensing of the rotor position of the motor 2 fails, a voltage is applied to the motor 2 at an inappropriate timing, and as a result, an overcurrent flows. The cause of failure in sensing of the rotor position is that noise is superimposed on the detected current of the motor 2, or the load of the pump module 1 changes rapidly, and the rotational speed of the motor 2 changes rapidly. have.

In addition, error 3 is likely to occur when the pump module 1 (and motor 2) is idle. The idle operation refers to an operation in which the motor 2 is rotated at an idle speed lower than the rated speed of the motor 2 for the purpose of saving energy. For example, in idle operation, the motor 2 is rotated at a speed of 10% of the rated speed of the motor 2. The inverter device 5 is adjusted so as to perform appropriate speed control when the motor 2 is rotating at its rated speed. If the difference between the idle speed and the rated speed is large, the control operation of the inverter control unit 16 becomes unstable, and an overcurrent may flow.

Error 4 is an error caused by a failure of the motor 2. For this reason, when the error 4 occurs, the operation of the inverter device 5 must be stopped immediately, and the motor 2 must be repaired or replaced.

As described above, errors of the inverter device 5 are largely divided into overvoltage errors and overcurrent errors. In addition, the overvoltage error is divided into an error 1 due to an abnormality in the power supply source 9 and an error 2 due to hunting in the inverter control, and the overcurrent error is an error 3 due to hunting in the inverter control, and the motor 2 ), it is divided into 4 errors. When these errors 1 to 4 occur, the inverter device 5 stops its operation and transmits an error signal to the control device 7.

Of the four errors 1 to 4, errors 1 and 4 are serious errors. In other words, if the operation of the inverter device 5 is continued after errors 1 and 4 have occurred, there is a risk that the inverter device 5 may fail. Therefore, when errors 1 and 4 occur, it is necessary to stop the operation of the inverter device 5.

In contrast, errors 2 and 3 are relatively light errors. For example, when the rotational speed of the motor 2 rotating by inertia decreases and the regenerative energy decreases, overvoltage and overcurrent do not occur. In addition, even if the sensing of the rotor position has failed, there is a case where the sensing of the rotor position can be accurately performed at the next moment. Since these errors 2 and 3 are not caused by a failure of the inverter device 5 itself, but are caused by hunting of the control of the inverter device 5, it is not necessary to stop the operation of the inverter device 5 There is also.

Therefore, in order to avoid frequent operation stoppage of the vacuum pump due to occurrence of an error, the control device 7 is configured to immediately restart the inverter device 5 when errors 2 and 3 occur.

When any one of errors 1 to 4 occurs, an error signal is sent from the inverter device 5 to the control device 7. Accordingly, the control device 7 can detect the occurrence of an error by receiving this error signal. When the occurrence of an error satisfies a predetermined condition, the control device 7 determines that the error is an error 2 or an error 3, and restarts the inverter device 5. The predetermined conditions are the following three conditions.

Condition 1: An error has occurred within a predetermined time (within 10 seconds, preferably within 5 seconds, more preferably within 2 seconds) after the power failure (instantaneous power failure) is restored and the supply of power is resumed. .

Condition 2: Within a predetermined time (within 10 seconds, preferably within 5 seconds, more preferably within a predetermined time from the time when the inverter device 5 starts deceleration of the motor 2 in accordance with the command from the control device 7) Is within 2 seconds).

Condition 3: Error when the inverter device 5 is rotating the motor 2 at an idle speed lower than its rated speed (less than 50%, preferably less than 30%, more preferably less than 10% of the rated speed) What happened.

The control device 7 restarts the inverter device 5 when the occurrence of an error satisfies any one of condition 1, condition 2, and condition 3. On the other hand, when the occurrence of an error does not satisfy any of condition 1, condition 2, and condition 3, the error is considered to be errors 1 and 4 described above, so that the control device 7 is the inverter device 5 Do not restart. The reason for setting the above conditions 1 to 3 is that errors 2 and 3 are, as described above, when the inverter device 5 is restarted immediately after a momentary power failure, when the motor 2 is actively decelerated, and the motor (2) This is because it is likely to occur when children are driving.

3 is a graph showing a change in the rotational speed of the motor 2 when an error occurs when the motor 2 is in idle operation. As shown in Fig. 3, when an error occurs when the motor 2 is rotating at an idle speed, the inverter device 5 sends an error signal to the control device 7 and stops its operation once. . The control device 7 restarts the inverter device 5 because the occurrence of the error satisfies the condition 3. The motor 2 rotates again before stopping completely, continuing to drive the pump module 1. In this way, even if an error occurs, the inverter device 5 continues its operation, so that the pump module 1 can continue evacuating the sealed container 8.

4 is a graph showing a change in the rotational speed of the motor 2 when an error occurs when the inverter device 5 is decelerating the motor 2 in response to a command from the control device 7. As shown in Fig. 4, if an error occurs while the inverter device 5 is decelerating the motor 2, the inverter device 5 sends an error signal to the control device 7 and once the operation is performed. Stop. The control device 7 restarts the inverter device 5 because the occurrence of the error satisfies the condition 2. As shown in Fig. 4, when an error occurs again within a predetermined time (within 10 seconds, preferably within 5 seconds, more preferably within 2 seconds) after the inverter device 5 restarts, the control The device 7 may restart the inverter device 5 again.

Errors 2 and 3 are relatively light errors, but a high frequency of occurrence may lead to a serious failure. Thus, the control device 7 determines whether to continue or stop the operation of the inverter device 5 based on the frequency of occurrence of errors 2 and 3. More specifically, the control device 7 counts the number of times an error (error 2 or error 3) has occurred, and does not restart the inverter device 5 when the counted number reaches a predetermined threshold. Consists of.

As shown in Fig. 1, the control device 7 includes a counter 22 that counts the number of errors and a timer 23 that measures the monitoring time. When an error does not occur within a predetermined monitoring time, the control device 7 resets the counted number to zero. This is because it is considered that the frequency of occurrence of errors 2 and 3 is low that the error does not occur within the predetermined monitoring time.

5 is a diagram for explaining the operation of the counter 22 for counting the number of errors and the timer 23 for measuring the monitoring time. When an error (error 2 or 3) occurs, the counter 22 counts the number of occurrences of the error, and at the same time, the timer 23 starts. Next, when an error (error 2 or 3) occurs, the counter 22 counts the number of occurrences of the error, and at the same time, the timer 23 is reset to zero and starts again. When no error occurs during a predetermined monitoring time (10 seconds in Fig. 5), the number of counted errors is reset to zero.

When an error (error 2 or error 3) occurs again, the counter 22 counts the number of occurrences of the error from 1, and at the same time, the timer 23 starts. As a result of repeating the count of the number of errors and the reset/start of the timer 23, when the counted error number reaches a predetermined threshold (three times in Fig. 5), the control device 7 Even if an error occurs, the inverter device 5 is not restarted. As a result, the supply of electric power from the inverter device 5 to the motor 2 is stopped, and accordingly, the pump module 1 is also stopped.

When an error occurs before a predetermined monitoring time elapses, it means that the frequency of error occurrence is high. Therefore, in this case, the control device 7 can protect the inverter device 5 from failure by not restarting the inverter device 5.

Next, another embodiment of the present invention will be described. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the above-described embodiment, and overlapping descriptions thereof are omitted. In this embodiment, the control device 7 is configured to transmit an error cancellation signal to the inverter device 5 for releasing an error occurring within a predetermined period, and the inverter device 5 receives the error cancellation signal, When an error occurs within the predetermined period, it is configured not to stop its operation.

The predetermined time is the following three periods.

Period 1: The period from the time when the power failure is restored and the supply of power is resumed until a predetermined time (10 seconds, preferably 5 seconds, more preferably 2 seconds) elapses.

Period 2: A predetermined time (10 seconds, preferably 5 seconds, more preferably 2 seconds) from the time when the inverter device 5 starts deceleration of the motor 2 according to the command from the control device 7 The period until this elapses.

Period 3: The period during which the inverter device 5 is rotating the motor 2 at an idle speed lower than its rated speed (less than 50%, preferably less than 30%, more preferably less than 10% of the rated speed).

6 is a graph for explaining that the inverter device 5 is in the error canceling mode during periods 1, 2, and 3; The control device 7 transmits an error cancellation signal to the inverter device 5 at the starting point of the periods 1, 2, and 3 above. Inverter device 5 receives this error cancellation signal and cancels errors occurring within periods 1, 2, and 3. According to this embodiment, since the error is canceled, the inverter device 5 does not stop. Accordingly, a decrease in the rotational speed of the motor 2 can be avoided, and the pump module 1 can maintain the vacuum pressure in the sealed container 8.

The error occurring during the periods 1, 2, and 3 is considered to be error 2 or error 3 described above. On the other hand, errors occurring other than the periods 1, 2, and 3 are considered to be error 1 or error 4 described above. Since the error canceling signal puts the inverter device 5 into the error canceling mode only within periods 1, 2, and 3, when an error occurs other than periods 1, 2, and 3, the inverter device 5 stops its operation. .

Also in this embodiment, whenever an error occurs, the inverter device 5 transmits an error signal to the control device 7. As in the above-described embodiment, the control device 7 counts the number of times an error (error 2 or error 3) has occurred, and when no error occurs within a predetermined monitoring time (eg, 10 seconds), the counted number is zero. Is reset to, and is configured not to transmit an error cancellation signal to the inverter device 5 when the counted number of times reaches a predetermined threshold value. Therefore, if an error occurs after the counted number of times reaches a predetermined threshold value, the error is not canceled, and the inverter device 5 stops its operation.

7 is a schematic diagram showing a vacuum pump according to another embodiment of the present invention. The configuration and operation of the present embodiment, which are not specifically described, are the same as those of the embodiment shown in Fig. 1, and therefore, overlapping descriptions thereof are omitted. When an error occurs, the inverter device 5 stops its own operation, and the control device 7 is configured to restart the inverter device 5 after the operation of the inverter device 5 stops. have. The types of errors include all types of errors including errors due to overcurrent and errors due to overvoltage. That is, regardless of the type of error, when an error occurs, the inverter device 5 stops its own operation.

As a result of the occurrence of an error, even if the operation of the inverter device 5 is stopped, the inverter device 5 is immediately restarted by the control device 7. Accordingly, a decrease in the rotational speed of the motor 2 is avoided, and the pump module 1 can maintain the vacuum pressure in the sealed container 8. However, if the inverter device 5 is forcibly restarted when an error occurs frequently, there is a fear that the inverter device 5 will fail. Therefore, the control device 7 is configured not to restart the inverter device 5 when the number of errors occurring within the set time reaches a predetermined threshold value n. n is a natural number of 3 or more (n≥3) and is predetermined.

As shown in FIG. 7, the control device 7 includes a plurality of timers 23 for measuring time. The logarithm of these timers 23 is a number obtained by subtracting 1 from the predetermined threshold value n, that is, n-1. Each of the plurality of timers is configured to measure time, terminate time measurement when the measured time reaches a set time, and reset the measured time to zero. Whenever an error occurs, the control device 7 starts any one of a plurality of timers, and does not restart the inverter device 5 when all of the plurality of timers are measuring time when an error occurs. Consists of.

Fig. 8 is a time chart for explaining the operation of a timer when an error occurs at a low frequency. In the example shown in Fig. 8, five timers 23A, 23B, 23C, 23D, and 23E are provided, and the setting time is 10 minutes. Whenever an error occurs, the control device 7 (see Fig. 7) starts any one of these timers 23A, 23B, 23C, 23D, and 23E in a predetermined order. In this example, when an error E1 occurs, the timer 23A is started to start time measurement. When the error E2 occurs, the timer 23B is started to start time measurement. Similarly, when errors E3, E4, and E5 occur, the timers 23C, 23D, and 23E are started in this order.

The timers 23A to 23E terminate time measurement when the measured time reaches the set time of 10 minutes, and reset the measured time to zero. Therefore, when the frequency of occurrence of the error is low, when the sixth error E6 occurs, the time measurement operation of the first timer 23A has already ended, and the timer 23A can restart time measurement. . In this way, when an error occurs at a low frequency, any one of the five timers 23A to 23E can start time measurement whenever an error occurs.

On the other hand, FIG. 9 is a time chart for explaining the operation of the timer when an error occurs at a high frequency. In this example as well, the five timers 23A to 23E are sequentially started when errors E1 to E5 occur. However, when the sixth error E6 occurs, the first timer 23A is still measuring time. The other timers 23B to 23E are also measuring time in the same way. In this way, when the error occurs at a high frequency, since the previous time measurement has not been completed for all timers including the timer 23A, time measurement cannot be started.

As can be seen from Fig. 9, when an error occurs, the fact that all the n-1 timers 23 are measuring time means that an error has occurred n times within the set time, that is, an error occurs at a high frequency. Means that there is. Therefore, in this case, the control device 7 prevents a failure of the inverter device 5 in advance by not restarting the inverter device 5. On the other hand, as shown in Fig. 8, when the error occurs at a low frequency, the control device 7 immediately restarts the inverter device 5 and continues the operation of the pump module 1.

In this embodiment, a plurality of timers 23 are employed in order to determine whether the number of errors occurring within a set time has reached a predetermined threshold value. Using one timer, it is possible to determine whether or not the number of errors occurring within a set time has reached a predetermined threshold value, but by using a plurality of timers 23, it is possible to quickly and also quickly detect that the error has occurred at a high frequency. It can be detected reliably. Hereinafter, the advantages of using a plurality of timers 23 will be described with reference to FIGS. 9 and 10.

In the example shown in Fig. 9, the threshold value of the number of occurrences of errors is set to 6. In other words, it is allowed to generate an error up to 5 times within the set time (10 minutes in Fig. 9), but when the error occurs 6 times, the control device 7 does not restart the inverter device 5. Fig. 10 is a time chart for explaining a method of determining whether or not the number of errors occurring within a set time reaches a predetermined threshold using one timer. Similarly in the example shown in Fig. 10, the threshold value of the number of occurrences of errors is set to 6.

As shown in Fig. 10, the timer repeatedly measures the set time (10 minutes in Fig. 10), and the control device 7 counts the number of errors occurring within this set time. Errors E1, E2, E3, and E4 have occurred within the first set time. Therefore, the number of errors occurring within the first set time is 4, which is smaller than the threshold value 6. The errors E5, E6, E7, and E8 occur within the following set time. Therefore, the number of errors occurring within the next set time is also 4, which is smaller than the threshold value 6.

However, errors E2, E3, E4, E5, E6, and E7 occur within 10 minutes of the set time. This means that 6 errors occur within 10 minutes. In the case of using only one timer, there may be a case where the control device 7 cannot detect the occurrence of such high frequency errors.

In contrast, according to the present embodiment shown in Fig. 9, each time an error occurs, any one of the plurality of timers 23A to 23E sequentially starts time measurement. Therefore, the control device 7 can quickly and reliably detect that an error has occurred at a high frequency.

The above-described embodiment has been described for the purpose of enabling a person of ordinary skill in the technical field to which the present invention pertains to practice the present invention. Various modifications of the above-described embodiment can naturally be achieved by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, and is to be interpreted as the widest scope according to the technical idea defined by the scope of the claims.

1: pump module 2: motor
5: inverter device 7: control device
8: sealed container 11: converter unit
15: smoothing capacitor 12: inverter unit
13: gate driver 16: inverter control unit
22: counter 23, 23A~23E: timer

Claims (24)

A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
Control device for controlling the inverter device
And, in the case of an error caused by overvoltage or overcurrent, the inverter device stops its operation,
The control device, when the occurrence of the error satisfies a predetermined condition, restarts the inverter device before the motor completely stops, thereby continuing the operation of the pump module. The vacuum pump according to claim 1, wherein the predetermined condition is that an error occurs within a predetermined time after power failure is restored and power supply is restarted. The vacuum pump according to claim 1, wherein the predetermined condition is that an error occurs within a predetermined time from a time when the inverter device starts deceleration of the motor according to a command from the control device. The vacuum pump according to claim 1, wherein the predetermined condition is that an error occurs when the inverter device is rotating the motor at an idle speed lower than its rated speed. The method according to any one of claims 1 to 4, wherein the control device counts the number of times the error has occurred, and when the error does not occur within a predetermined monitoring time, resets the counted number to 0, When the counted number of times reaches a predetermined threshold value, the inverter device is not restarted. A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
Control device for controlling the inverter device
And, in the case of an error caused by overvoltage or overcurrent, the inverter device stops its operation,
The control device transmits an error cancellation signal to the inverter device for canceling an error occurring within a predetermined period,
The inverter device, upon receiving the error cancellation signal, does not stop its own operation when the error occurs within the predetermined period. The vacuum pump according to claim 6, wherein the predetermined period is a period from a point in time when a power failure is restored and power supply is resumed until a predetermined time elapses. The vacuum pump according to claim 6, wherein the predetermined period is a period from a point in time when the inverter device starts deceleration of the motor according to a command from the control device until a predetermined time elapses. The vacuum pump according to claim 6, wherein the predetermined period is a period in which the inverter device rotates the motor at an idle speed lower than its rated speed. The method according to any one of claims 6 to 9, wherein the control device counts the number of times the error has occurred, and resets the counted number to zero when the error does not occur within a predetermined monitoring time, And when the counted number of times reaches a predetermined threshold value, the error cancellation signal is not transmitted to the inverter device. A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
Control device for controlling the inverter device
And, the inverter device, when an error occurs, stops its operation,
Wherein the control device immediately restarts the inverter device after the operation of the inverter device stops, and does not restart the inverter device when the number of errors occurring within a set time reaches a predetermined threshold value. Vacuum pump. The method of claim 11, wherein the control device is provided with a plurality of timers for measuring time, the number of the plurality of timers is equal to a number minus one from the predetermined threshold, each of the plurality of timers , When the measured time reaches the set time, it is configured to end time measurement,
The control device,
Whenever an error occurs, any one of the plurality of timers is started,
When an error occurs, when all of the plurality of timers are performing time measurement, the inverter device is not restarted. A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
A method of operating a vacuum pump including a control device for controlling the inverter device,
When an error due to overvoltage or overcurrent occurs, the operation of the inverter device is stopped,
If the occurrence of the error satisfies a predetermined condition, the inverter device is restarted before the motor completely stops, thereby continuing the operation of the pump module. 14. The method of claim 13, wherein the predetermined condition is that an error occurs within a predetermined time after power failure is restored and power supply is resumed. The operation of a vacuum pump according to claim 13, wherein the predetermined condition is that an error occurs within a predetermined time from a time when the inverter device starts deceleration of the motor according to a command from the control device. Way. The method of operating a vacuum pump according to claim 13, wherein the predetermined condition is that an error occurs when the inverter device is rotating the motor at an idle speed lower than its rated speed. The method according to any one of claims 13 to 16, wherein the number of times the error occurs is counted,
When the error does not occur within a predetermined monitoring time, the counted number is reset to 0,
When the counted number of times reaches a predetermined threshold value, the inverter device is not restarted. A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
A method of operating a vacuum pump including a control device for controlling the inverter device,
When an error due to overvoltage or overcurrent occurs, the operation of the inverter device is stopped,
An error cancellation signal for canceling an error occurring within a predetermined period is transmitted to the inverter device,
When the error occurs within the predetermined period, the operation of the inverter device is not stopped. 19. The method of operating a vacuum pump according to claim 18, wherein the predetermined period is a period from a time when a power failure is restored and power supply is resumed until a predetermined time elapses. The vacuum pump according to claim 18, wherein the predetermined period is a period from a point in time when the inverter device starts deceleration of the motor according to a command from the control device until a predetermined time elapses. Driving method. The method of operating a vacuum pump according to claim 18, wherein the predetermined period is a period during which the inverter device rotates the motor at an idle speed lower than its rated speed. The method according to any one of claims 18 to 21, wherein the number of times the error has occurred is counted,
When the error does not occur within a predetermined monitoring time, the counted number is reset to 0,
When the counted number of times reaches a predetermined threshold value, the error cancellation signal is not transmitted to the inverter device. A pump module that exhausts gas,
A motor driving the pump module,
An inverter device for supplying AC power of a variable frequency to the motor,
A method of operating a vacuum pump including a control device for controlling the inverter device,
When an error occurs, stop the operation of the inverter device,
Operation of a vacuum pump, characterized in that the inverter device is immediately restarted after the operation of the inverter device is stopped, and the inverter device is not restarted when the number of errors occurring within a set time reaches a predetermined threshold. Way. The method of claim 23, wherein the control device is provided with a plurality of timers for measuring time, the number of the plurality of timers is equal to a number minus one from the predetermined threshold, each of the plurality of timers , When the measured time reaches the set time, it is configured to end time measurement,
Whenever an error occurs, any one of the plurality of timers is started,
A method of operating a vacuum pump, wherein when an error occurs and all of the plurality of timers are measuring time, the inverter device is not restarted.

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