TWI707534B - Dry vacuum pump device, method of controlling same, and program of controlling same - Google Patents

Abstract

The present invention provides a dry vacuum pump device that can consume the regenerative power generated on the motor side when the power element of the inverter is powered off, and immediately supply power from the power supply to the inverter after the power supply is restored, and can restart the vacuum pump immediately after the power supply is restored , Its control method and control program. The present invention is provided with: a dry vacuum pump 1; a motor 2 that drives the dry vacuum pump 1; an inverter 11 that supplies variable frequency AC power to the motor 2 to control the rotation speed of the motor 2; and a control device 4 that controls the inverter 11 The control device 4 controls the inverter 11 in such a way that the switching element of the inverter 11 consumes the regenerative power generated on the motor side when the power fails, and after the power supply is restored, the inverter 11 supplies the driving power to the motor 2.

Description

Dry vacuum pump device and its control method and control program

The present invention relates to a dry vacuum pump device, its control method and control program, in particular to a vacuum pump that can be restarted immediately after a power failure such as a power failure that occurs in a short time of less than 1 second The rotation of the ura, or the dry vacuum pump device, its control method and control program that can immediately restore the speed of the vacuum pump to the rated state.

In the production lines of semiconductor components, liquid crystals, solar panels, LEDs, etc., dry vacuum pumping devices are widely used in order to vacuum exhaust the processing chambers where various processes are performed. The dry vacuum pumping device refers to a power failure such as a "momentary interruption" that occurs in a short time of less than 1 second. When the pumping operation control is stopped, the internal pressure of the processing chamber is caused by the exhaust of the vacuum pump. Ascends, the processing conditions in the processing chamber change, and the manufacturing process cannot be continued, causing the production line to stop. The longer the pump operation control stop time of the dry vacuum pump device due to power failure, the greater the damage. Therefore, it is hoped that the dry vacuum pump device will be restarted immediately after the power supply is restored. In addition, when the vacuum of the processing chamber is damaged due to a power failure, it will cause damage to the products being processed in the processing chamber. Therefore, it is hoped that the impact on the pressure in the processing chamber can be minimized even if the power is interrupted.

Generally speaking, a dry vacuum pump device has: a dry vacuum pump; a motor that drives the dry vacuum pump; an inverter that controls the rotation speed (rotation frequency) of the motor; and a control device that controls the operation of the inverter; Variable frequency AC power can control the running speed of dry vacuum pump.

In the dry vacuum pump device provided with the above-mentioned inverter, the power supply from the inverter device to the vacuum pump drive motor is stopped due to a power failure. Therefore, the vacuum pump is in a stopped state and the pump drive motor is in a decelerated state.

Then, when the input power supply is restored, the output control of the inverter device resumes its function. However, especially when a DC commutatorless motor with permanent magnets is used on the rotor side, when the pump motor is in a rotating state and the inverter output is to be restarted, it is the same as if the motor itself supplies power to the inverter output terminal. Electric motors, which generate a lot of regenerative power.

Because this regenerative power occurs at the output terminals of the inverter, as far as the inverter is concerned, it overlaps with the power supplied to the motor by the inverter itself and controls the regenerative power from the motor. Therefore, the power that the inverter must handle exceeds the normal use range. control. Therefore, the switching element inside the inverter will supply power and current exceeding the normal use, so it may cause malfunction when regenerative power occurs. The general method for protecting the switching element has been proposed as follows: install a regenerative resistor for consuming regenerative power, and use the resistor to dissipate the power of the regenerative part; without regenerative resistor, return the regenerative power The control method on the power supply side (input side); or the method in which the regenerative power is naturally attenuated due to the deceleration of the motor without resuming the control of the inverter before the motor is lower than the specified number of revolutions.

However, if the regenerative resistor consumes regenerative power, a regenerative resistor and a switching mechanism for allowing the regenerative current to flow through the regenerative resistor are required. Therefore, the number of parts increases, and the entire inverter device is enlarged and the cost increases.

In addition, when performing control to return regenerative power to the power supply side (input side), it is difficult to control power elements such as switching elements in the inverter. Since the cost of installing a control circuit also increases, it is necessary to return the regenerative power to the input side. There is a problem with control.

Therefore, in order to solve the above problems and avoid the cost increase of the device, it is usually in the dry vacuum pumping device that the regenerative power is not returned to the inverter side during a power failure, and the inverter control is not restored until the pump and motor are lower than the specified number of revolutions. , The regenerative power is consumed naturally by decelerating the motor. When the pump and motor are lower than the specified number of revolutions, the dry vacuum pump is started.

When the dry vacuum pump is running at the rated number of revolutions, there is a power failure, sometimes the pressure in the pump housing remains very low. When the drive current from the inverter is stopped, sometimes the rotation will not decelerate for a short time, but it will continue at the rated number of revolutions. Spin.

When power is restored in this state and the pump motor is energized again, the motor functions as a generator, so regenerative power is generated at the inverter output terminal. The current generated at the output terminal of the inverter due to the regenerative power may generate a current that is approximately the same as the current output by the inverter when the motor is driven. Therefore, the inverter-side switching element must not be able to handle a current that is twice the normal output current.

In order to avoid the occurrence of this regenerative power, the dry vacuum pump using the general inverter device is to wait for the rotation of the pump motor to be sufficiently reduced after a power failure to start the output of the inverter side. method.

In addition, when the speed of the dry vacuum pump decreases, because the pump performance decreases and the gas exhaust speed in the processing chamber decreases, the pressure in the processing chamber will rise, which will break the vacuum of the processing chamber and damage the products being manufactured in the processing chamber.

In addition, when dry vacuum pumps are used for semiconductor manufacturing equipment, the SEMI specification formulated as the industry standard for semiconductor manufacturing equipment has provisions on instantaneous power failures, requiring that the normal operation should continue when a power failure occurs within 1 second, and the pump will be fast when power is restored Resume rotation.

Therefore, the dry vacuum pumps used in semiconductor manufacturing equipment can restore power after a power outage Later, the control method of pump motor or pump speed recovery becomes a major issue.

【Prior Technical Literature】 【Patent Literature】

[Patent Document 1] JP 2010-110139 A

[Patent Document 2] JP 2011-69294 A

However, as mentioned above, the method of waiting for the dry vacuum pump to restart before consuming the regenerative power on the motor side, because the internal pressure of the processing chamber rises during the deceleration of the dry vacuum pump, and the processing conditions deteriorate, so there is a problem of excessive impact on the production line.

Therefore, the inventors used the power elements of the inverter to consume the regenerative power generated on the motor side during a power failure, and when the power supply was restored within a short time within 1 second, the inventors immediately supplied power to the inverter and restarted the dry vacuum pump. Conduct a review.

The present invention is in view of the above situation, and its purpose is to provide a regenerative power that can be generated on the motor side when the power element of the inverter consumes power failure, and the power is supplied from the power supply to the inverter immediately after the power supply is restored. The dry vacuum pump device for starting the vacuum pump, its control method and control program.

In addition, an object of the present invention is to provide a dry vacuum pump device, a control method and a control program thereof that can minimize the internal pressure fluctuation of the processing chamber of the exhaust target due to a momentary power failure.

In order to achieve the above object, the first aspect of the dry vacuum pump device of the present invention is characterized by: a dry vacuum pump; a motor, which drives the aforementioned dry vacuum pump; and frequency conversion A device that supplies variable-frequency AC power to the aforementioned motor to control the rotation speed of the motor; and a control device that controls the aforementioned frequency converter; the aforementioned control device uses the switching element of the aforementioned frequency converter to consume in the event of a power failure The regenerative power generated on the motor side is used to control the inverter by supplying drive power from the inverter to the motor after the power supply is restored.

The characteristic of the suitable aspect of the present invention is that the aforementioned frequency converter is a frequency converter whose rated current of the aforementioned switching element is 1.5 to 3.0 times of the rated current of the universal frequency converter.

In the first aspect of the control method of the dry vacuum pump device of the present invention, the dry vacuum pump device includes: a dry vacuum pump; a motor that drives the dry vacuum pump; and a frequency converter that supplies variable frequency AC The electric power is supplied to the aforementioned motor to control the rotation speed of the motor; its characteristic is that the output of the aforementioned inverter is stopped at the same time as the power is cut, and the regenerative power generated on the motor side is consumed by the switching element of the aforementioned inverter, and immediately when the power supply is restored Start the control of the aforementioned inverter output.

The first aspect of the control program of the dry vacuum pump device of the present invention is provided. The dry vacuum pump device includes: a dry vacuum pump; a motor that drives the dry vacuum pump; and a frequency converter that supplies variable frequency AC Electric power is supplied to the motor to control the rotation speed of the motor; the feature is that the dry vacuum pump device uses the control program to stop the output of the inverter at the same time as the power is cut, and the switching element of the inverter is consumed on the motor side. When the power supply is restored, the output of the inverter will be started to control the inverter.

The second aspect of the dry vacuum pump device of the present invention is characterized by: a dry vacuum pump; a motor, which drives the dry vacuum pump; and a frequency converter, which supplies variable frequency AC power to the motor to control the motor The rotation speed; and the control device, which controls Manufacture the aforementioned inverter; the aforementioned control device has the function of detecting a power failure, and the aforementioned control device controls the aforementioned inverter in such a way that the aforementioned inverter supplies 1.5 to 3.0 times the rated current of the inverter to the motor after power is restored from a power failure. .

The characteristic of the suitable aspect of the present invention is that after the power supply is restored, when the speed of the dry vacuum pump is restored to the specified speed, the frequency converter is controlled by the frequency converter to supply the current below the rated current of the frequency converter to the motor. Device.

The suitable aspect of the present invention is characterized in that: the rated current of the switching element of the aforementioned frequency converter is 1.5 to 3.0 times the rated current of the aforementioned frequency converter.

In the second aspect of the control method of the dry vacuum pump device of the present invention, the dry vacuum pump device includes: a dry vacuum pump; a motor that drives the dry vacuum pump; and a frequency converter that supplies variable frequency AC Electric power is supplied to the aforementioned motor to control the rotation speed of the motor; the characteristic is that the aforementioned frequency converter supplies a current 1.5 to 3.0 times the rated current of the frequency converter to the motor after the power supply is restored from a power failure.

The characteristic of the suitable aspect of the present invention is that after the power supply is restored, when the speed of the dry vacuum pump returns to a specified speed, the inverter is controlled in such a way that the inverter supplies a current below the rated current of the inverter to the motor.

The suitable aspect of the present invention is characterized in that: the rated current of the switching element of the aforementioned frequency converter is 1.5 to 3.0 times the rated current of the aforementioned frequency converter.

The second aspect of the control program of the dry vacuum pump device of the present invention. The dry vacuum pump device includes: a dry vacuum pump; a motor that drives the dry vacuum pump; and a frequency converter that supplies variable frequency AC Electricity is applied to the aforementioned motor to control the rotation speed of the motor; the feature is that the aforementioned dry vacuum pumping device uses the aforementioned control program to avoid power failure After the power supply is restored, the aforementioned frequency converter supplies 1.5 to 3.0 times the rated current of the frequency converter to the motor to control the aforementioned frequency converter.

The feature of the suitable aspect of the present invention is that the dry vacuum pump device uses the control program after the power supply is restored, and when the speed of the dry vacuum pump returns to the specified speed, the inverter supplies the inverter with a rated current below The way of current to the motor controls the aforementioned inverter.

When the present invention is adopted, the power element of the inverter can consume the regenerative power generated on the motor side during a power failure, and supply power from the power supply to the inverter immediately after the power supply is restored, so the dry vacuum pump can be restarted immediately after the power supply is restored. Therefore, the internal pressure fluctuation of the processing chamber exhausted by the dry vacuum pump can be suppressed.

In addition, when the present invention is used, when an instantaneous power failure is detected and recovered from the instantaneous power failure, by supplying a large current that is several times the rated current of the inverter from the inverter to the motor, the pump speed reduced by the power failure can be immediately restored . Therefore, the internal pressure fluctuation of the processing chamber exhausted by the dry vacuum pump can be extremely small.

1: Dry vacuum pump

2: motor

3: Motor driver

4: control device

5: Processing room

6: Circuit breaker

7: AC power

10: converter

11: Inverter

12: Drive control section

C1: Capacitor

V: voltage

S1~S6: switching element

The first figure is a schematic diagram showing the overall structure of the dry vacuum pump device of the present invention.

The second (a) diagram and the second (b) diagram are comparisons showing the control curve of the dry vacuum pump device of the past technology and the control curve of the dry vacuum pump of one aspect of the present invention. The second (a) diagram shows the past technology Control of the dry vacuum pumping device. The second (b) diagram shows the control of the dry vacuum pumping device in one aspect of the present invention.

The third (a) diagram and the third (b) diagram show the control curve of the dry vacuum pumping device of the past technology and the control curve of the dry vacuum pumping device of one aspect of the present invention. The third (a) diagram shows the past technology Control of the dry vacuum pumping device. The third (b) diagram shows the control of the dry vacuum pumping device in one aspect of the present invention.

The fourth figure is a graph showing a state of the inverter control method of the present invention.

The fifth figure shows the control flow chart of the inverter of the present invention.

Hereinafter, embodiments of the dry vacuum pump device, its control method and control program of the present invention will be described with reference to the first to fifth figures. In the first to fifth figures, the same or equivalent elements are denoted with the same symbols and repeated descriptions are omitted.

The first figure is a schematic diagram showing the overall structure of the dry vacuum pump device of the present invention. As shown in the first figure, the dry vacuum pump device includes: a dry vacuum pump 1, a motor that rotationally drives the dry vacuum pump 1, a motor driver 3 that controls the rotation speed of the motor 2, and a control device 4 that controls the operation of the motor driver 3 . The motor driver 3 is connected to an AC power source 7 such as a commercial power source via a circuit breaker 6. The air inlet of the dry vacuum pump 1 is connected to a processing chamber 5 of a semiconductor manufacturing device or the like, and is constructed in such a way that the dry vacuum pump 1 exhausts the processing chamber 5 to a vacuum.

The motor driver 3 includes: a converter 10 that converts the AC power supplied from the AC power source 7 into DC power; an inverter 11 that converts the converted DC power into AC power with a desired frequency; and an instruction to switch the inverter 11 The gate drive signals of the ON-OFF actions of the elements S1 to S6 are transmitted to the driver control section 12 of the inverter 11. The converter 10 includes a capacitor C1 for smoothing the voltage.

The driver control unit 12 generates according to the operation command speed of the dry vacuum pump 1, etc. PWM signal and send it to the inverter 11. The control device 4 is configured to control the operation of the entire drive 3 and further communicate with an external upper-level machine. The driver control unit 12 obtains the current value supplied from the motor driver 3 to the motor 2 as the operation information of the motor 2, calculates the rotation speed of the motor 2 from the current value, and generates a PWM signal based on the difference between the predetermined target rotation speed and the calculated rotation speed , And transmit it to the inverter 11 of the motor driver 3. The inverter 11 drives the switching elements S1 to S6 in accordance with the PWM signal, and applies an input voltage for rotating the motor 2 at the target rotation speed to the motor 2. Furthermore, the control device 4 is configured to transmit the start signal and the stop signal of the dry vacuum pump 1 to the driver control unit 12 according to the operation of the user.

In the dry vacuum pump device constructed as shown in the first figure, in the event of a power failure such as an instantaneous power failure, the dry vacuum pump 1 stops operating, but the motor 2 decelerates as the operation stops, and regenerative power is generated in the motor 2. This regenerative power is returned to the inverter 11.

This is because when the power supply is restored after a power failure, the control device 4 transmits the start signal of the dry vacuum pump 1 to the motor driver 3, or continues to transmit the start signal even during a power failure, and is supplied from the AC power supply 7 for driving The electric power of the motor is connected to the inverter 11, so the regenerative electric power from the motor 2 and the electric power supplied from the AC power source 7 for driving the motor are superimposed in the inverter 11. That is, because the regenerative current from the motor 2 and the current for driving the motor from the AC power source 7 are overlapped in the inverter 11, the inverter 11 needs to withstand the overlapped large current. Therefore, in the present invention, with regard to the rated current of the switching element of the inverter, a dedicated inverter whose rated current is larger than that of a general-purpose inverter is used.

The relationship between the rated power of the general-purpose inverter and the rated current specification of the switching element used, each inverter manufacturer adopts its own calculation method, and Table 1 is a comparison table of an example and the special inverter used in the present invention.

Table 1 refers to the rated current of the switching element. The rated power of each inverter is compared and compared with general-purpose inverters and special-purpose inverters. It can be understood from Table 1 that the rated current (setting) of the switching element in the present invention is a special inverter that is 1.5 times to 2.5 times that of a general inverter. According to the inventor's opinion, the ratio of the rated current of the special inverter to the general inverter of the present invention is not limited to 1.5 times to 2.5 times, as long as it is in the range of 1.5 times to 3.0 times.

In this way, by configuring the inverter 11 with an inverter having a switching element that can withstand large currents, the power device of the inverter 11 consumes the regenerative power generated on the motor side during a power failure, and supplies power from the AC power supply 7 to the inverter 11. The dry vacuum pump can be restarted immediately after the power supply is restored after a short-term power failure occurs within 1 second.

The second (a) diagram and the second (b) diagram are comparison showing the control curve of the dry vacuum pump device of the past technology and the control curve of the dry vacuum pump 1 of one aspect of the present invention. The second (a) diagram shows the past technology The control of the dry vacuum pumping device. The second (b) diagram shows the control of the dry vacuum pumping device 1 of one aspect of the present invention. In the second (a) and second (b) diagrams, the horizontal axis represents time (t), and 1s represents 1 second. The vertical axis represents the input voltage (V) to the inverter, the output of the inverter, the pump revolution (rpm) and the pressure in the processing chamber.

As shown in the second (a) diagram, the past technology disconnected the input voltage of the inverter due to a momentary power failure (OFF), the output of the inverter is also disconnected. Even if the power supply is restored after a momentary power failure, the number of revolutions of the motor will still decrease without generating regenerative power, or because the generated regenerative power is very small and waiting, the inverter output disconnected state continues for nearly 1 second. When the inverter output is disconnected, the pump revolutions will decrease, and the pressure in the processing chamber will increase. The second (a) figure shows three states of instantaneous power failure: short, slightly longer, and medium time. However, regardless of the length of the instantaneous power failure, the inverter output will be disconnected for about 1 second. In either state , The reduction in pump revolutions and the increase in pressure in the treatment chamber are approximately the same.

As shown in the second (b) figure, when the input voltage to the inverter is disconnected due to an instantaneous power failure, although the output of the inverter is also disconnected, when the power supply is restored, there is no need to reduce the speed of the motor. Waiting while the regenerative power is reduced, the inverter output is turned on (ON) immediately. The second (b) figure also shows three modes of instantaneous power failure: short time, slightly longer time, and medium time. In any of these modes, the inverter output is turned on immediately when the power supply is restored. In this way, because the inverter output is turned on immediately after the power supply is restored, the decrease in pump revolutions and the increase in pressure in the processing chamber can be suppressed.

The third (a) and third (b) diagrams show the control of the dry vacuum pumping device of the past technology and the control curve diagrams of the dry vacuum pumping device 1 of one aspect of the present invention. The third (a) diagram shows the past technology The third (b) diagram shows the control of the dry vacuum pumping device 1 of one aspect of the present invention. In the third (a) and third (b) figures, the horizontal axis represents time (t), and 1s represents 1 second. The vertical axis represents the input voltage (V) to the inverter, the output of the inverter, the pump revolution (rpm) and the pressure in the processing chamber.

As shown in the third (a) diagram, in the past technology, when instantaneous power failure occurred repeatedly in a short period of time (the diagram shows the situation where three instantaneous power failures occur repeatedly every 1 second), the input voltage of the inverter is due to the initial When the inverter is disconnected due to a momentary power failure, the inverter output will be disconnected, and the power supply will be restored temporarily, but because of waiting for the occurrence of regenerative power reduction, the inverter output is not turned on before the next momentary power failure, and the inverter output is disconnected The state continued to the last moment of power outage. When the power supply is restored after the last moment of power failure, the inverter output turn-on time is delayed. In this way, when instantaneous power failure occurs repeatedly in a short time, the disconnected state of the inverter output lasts for a long time (3 seconds in the example in the figure). During this period, the pump revolution continued to decrease and decreased to 0 rpm. Therefore, the pressure in the processing chamber rises to the highest level (High).

As shown in the third (b) diagram, one aspect of the present invention occurs when an instantaneous power failure occurs repeatedly in a short period of time (the figure shows that three instantaneous power failures occur repeatedly every 1 second), although the input voltage of the inverter is When the power supply is turned off, the inverter output will be turned off at the time, but since there is no need to wait while the regenerative power is reduced, the inverter output will immediately return to on regardless of the length of the instantaneous power failure when the power supply is restored. In the event of a momentary power failure, although the pump revolutions are slightly reduced at that time, the inverter output is restored immediately after the power supply is restored, so the pump revolutions decrease and the pressure rise in the processing chamber is also small. Therefore, the processing room pressure reaches the lowest level (Low) immediately when the inverter output is restored. In this way, when the present invention is adopted, even if the output of the inverter is cut off due to a power failure, because the output of the inverter can be turned on immediately after the power supply is restored, the revolution of the vacuum pump can be restored to the rated revolution in a short time. Changes in pressure.

Here, the rated current of the inverter itself is selected through experiments according to the specifications required by the pump (exhaust speed, exhaust time, and allowable gas flow, etc.). The so-called rated current of the inverter is the maximum current value that the inverter can continuously output. The internal switching elements, other parts and cooling mechanism of the inverter are designed so that there is no problem even if the inverter continuously outputs the rated current of the inverter. Here, the rated current of the switching element of the inverter in the present invention is 1.5 to 3.0 times the rated current of the inverter. Compared with the rated current of the switching element, by suppressing the Low, the parts and cooling mechanism other than the switching element of the inverter can be adapted to low current, which can avoid the large-scale inverter and reduce the cost.

The control device 4 in the first figure is provided with a connector (not shown) for connecting the storage medium reading device, and the storage medium reading device can be connected as needed to read the control program and data from the external storage medium. Then, as mentioned above, by providing a storage medium, it is stored for power recovery after a power failure, without waiting for the reduction of the motor's regenerative power, immediately turning on the control program for the control of the inverter output, and reading from the storage medium The control program is installed in the control device 4, and the present invention can be implemented in the existing vacuum pump device.

In the present invention shown in Figures 2 (b) and 3 (b), when the power supply is restored after an instantaneous power failure, the inverter output current supplied from the inverter 11 to the motor 2 is controlled below the rated current of the inverter 11 .

The inventor noticed that in order to restore the power supply after an instantaneous power failure, the inverter output current supplied from the inverter 11 to the motor 2 is controlled below the rated current of the inverter 11, and the motor output is limited and the number of revolutions of the vacuum pump is limited. , Compared with the ideal state, the pressure rise in the treatment chamber is large and the rise time is long.

Therefore, one aspect of the present invention is to set the inverter output current supplied from the inverter 11 to the motor 2 to be a multiple of the rated current of the inverter 11 when the power supply is restored after an instantaneous power failure. As a result, the pressure fluctuation of the processing chamber can be made smaller during a momentary power failure. Hereinafter, this aspect will be described with reference to the fourth and fifth figures.

The fourth figure is a graph showing a state of the inverter control method of the present invention. In the fourth figure, the horizontal axis represents time (t), and the vertical axis represents power supply voltage (V), pump revolutions (rpm), processing room pressure, and inverter output current (A).

As shown in the fourth figure, when an instantaneous power failure occurs, the power supply voltage is lost and the inverter output current is disconnected. As a result, the rotation speed of the vacuum pump gradually decreases. After the instantaneous power failure is restored and the power supply is restored, the inverter 11 will output 1.5 to 3.0 times of the rated current of the inverter, and even 2.0 to 3.0 times the inverter current to the motor 2. In this way, after the power supply is restored, because the inverter 11 supplies a large current 1.5 to 3.0 times the rated current of the inverter to the motor 2, the motor output becomes larger. As shown in the fourth figure, the pump rotation speed rises rapidly and in a short time Return to the specified rotation speed. Therefore, although the pressure in the processing chamber rises slightly after the instantaneous power failure, the rotation speed of the vacuum pump increases rapidly after the power supply is restored, and the pressure in the processing chamber quickly returns to the original pressure. Therefore, the pressure of the processing chamber fluctuates slightly. After the rotation speed of the vacuum pump is restored to the specified speed, the output current of the inverter is reduced to below the rated current of the inverter. In the control of reducing the output current of the inverter below the rated current of the inverter, the inverter 11 outputs an inverter current that meets the vacuum pump rotation speed required by the vacuum pressure on the side of the need, that is, the processing chamber side.

Because the rated current of the switching element of the present invention is 1.5 to 3.0 times the rated current of the inverter, the inverter 11 can supply a large current 1.5 to 3.0 times the rated current of the inverter to the motor 2 after the power supply is restored in an instantaneous power failure. .

In addition, even if an instantaneous power failure occurs and the power supply voltage is lost, if the control circuit such as the driver control unit 12 is effective and the charge is stored in the capacitor C1, the inverter 11 can output current. The present invention is effective when the power of the capacitor C1 is consumed during a power failure and the motor 2 cannot be supplied with power.

In the above description, the dry vacuum pump is a Roots dry vacuum pump and other rotary pumps. However, when the dry vacuum pump is a reciprocating pump, the rotation of the motor is converted into the reciprocating movement of the pump, so only The rotation speed of the pump must be replaced with the speed of the pump reciprocating motion.

The fifth figure shows the control flow chart of the inverter of the present invention. As shown in the fifth figure, when the inverter 11 starts to operate, the power supply voltage of the AC power supply 7 is measured, and the power supply voltage is compared with the specified voltage. When the power supply voltage is lower than the specified voltage (Yes), it is judged as a power failure and the inverter 11 No output (the inverter output is disconnected). When the power supply voltage is higher than the predetermined voltage (in case of No), return to the step of measuring the power supply voltage. After the inverter output is disconnected, measure the power supply voltage again. When the power supply voltage is higher than the specified voltage (Yes), it is determined that the power supply is restored, and the inverter output current (the inverter current limit) is increased to the inverter rated current. 1.5~3.0 times of that. Here, the so-called inverter limited current system control device 4 instructs the maximum current limit value output by the inverter 11 of the motor driver 3. When the power supply voltage is lower than the specified voltage (in case of No), return to the step of measuring the power supply voltage. After the above steps to increase the output current of the inverter, compare the pump speed with the specified speed. When the pump speed is greater than the specified speed (when it is (Yes)), it is judged that the instantaneous power failure recovery action has ended, and the inverter output current (inverter The current limit) is restored to the normal value below the rated current of the inverter, and the control process ends. If the pump speed is lower than the specified speed (in case of NO), return to the step of increasing the inverter output current. Here, the so-called designated speed refers to the speed within the range of 90% to 99% of the rated pump speed.

Regarding the measurement of the above-mentioned power supply voltage, the control device 4 is connected to the AC power supply side to measure the power supply voltage, or the driver control unit 12 is connected to the AC power supply side to measure the power supply voltage.

In addition, by having a memory medium storing a control program, the control program is used to control the inverter 11 in such a way that the inverter 11 supplies 1.5 to 3.0 times the rated current of the inverter to the motor after the power supply is restored from a power failure. By installing the control program on the control device 4 via the storage medium reading device as described above, the present invention can be implemented in the existing vacuum pump device.

In addition, in the present invention shown in Figure 4, the power supply is restored from an instantaneous power failure. The output current of the inverter reaches the limit current in recovery from an instantaneous power failure, but the present invention does not mean that the output current of the inverter must reach the limit current. Depending on the degree of pressure fluctuation in the processing chamber, sometimes the output current of the inverter during recovery from an instantaneous power failure exceeds the normal inverter rated current value, but the recovery action ends when it has not reached the limit current.

The above description is that the rated current of the switching element used is 1.5~3.0 times of the rated current of the inverter, and the inverter should be 2.0~3.0 times to recover from an instantaneous power failure. However, even if a general inverter is used, it is used If the rated current of the switching element is equal to or slightly greater than the rated current of the inverter, the present invention is still applicable. In other words, the limited current value of the inverter is increased to 1.5~3.0 times of the rated current of the inverter by a little time after the power supply is restored from an instantaneous power failure, even if the current flowing through the switching element for a short time exceeds the rated current of the switching element. The present invention can be applied when there is no malfunction. In this way, the rotation speed of the vacuum pump after the power supply is restored can still increase rapidly, so that the pressure in the processing chamber can be quickly restored to the original pressure.

In addition, the present invention can also be applied when a voltage drop occurs in a short time of about 1 second or less in addition to a power outage that occurs in a short time of about 1 second or less.

The above is the description of the embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments, and of course it can be implemented in various different forms within the scope of its technical idea.

1: Dry vacuum pump

2: motor

3: Motor driver

4: control device

5: Processing room

6: Circuit breaker

7: AC power

10: converter

11: Inverter

12: Drive control section

C1: Capacitor

V: voltage

S1~S6: switching element

Claims (4)

A dry vacuum pump device, characterized by: a dry vacuum pump; a motor that drives the dry vacuum pump; a frequency converter that supplies variable frequency AC power to the motor to control the rotation speed of the motor; and control A device that controls the inverter; the control device uses the switching element of the inverter to consume the regenerative power generated on the motor side when a power failure occurs, and makes the regenerative power from the motor and the commercial power supply from the power failure to recovery The supplied electric power for driving the motor overlaps each other, and the switching element of the aforementioned frequency converter is switched and controlled. For example, the dry vacuum pump device in the first item of the scope of patent application, in which the aforementioned inverter is an inverter whose rated current of the aforementioned switching element is 1.5 to 3.0 times the rated current of the switching element of a general-purpose inverter. A control method of a dry vacuum pump device, the dry vacuum pump device includes: a dry vacuum pump; a motor that drives the dry vacuum pump; and a frequency converter that supplies variable frequency AC power to the motor to control the motor The rotation speed; characterized by: the regenerative power generated on the motor side is consumed by the switching element of the inverter when the power is cut, and the regenerative power from the motor and the power supplied from the commercial power supply from the power failure to the recovery The electric power of the driving motor overlaps each other, and the switching element of the aforementioned inverter is controlled on and off. A control program of a dry vacuum pump device, the dry vacuum pump device has: dry A vacuum pump; a motor, which drives the aforementioned dry vacuum pump; and a frequency converter, which supplies variable frequency AC power to the aforementioned motor to control the rotation speed of the motor; characterized in that: the aforementioned dry vacuum pump device is driven by the aforementioned The control program uses the switching element of the inverter to consume the regenerative power generated on the motor side when a power failure occurs, and makes the regenerative power from the motor and the power supplied from the commercial power supply for driving the motor overlap each other from the power failure to the recovery. The switching elements of the aforementioned inverter are controlled on and off.

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