JP2010131624A - Electric motor controller for intermittent load driving - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller which makes a power equipment capacity minimum to the amount of the work to be required in an intermittent load, and further makes a power storage condenser capacity minimum. <P>SOLUTION: The electric motor controller includes: an energy storage apparatus 23 storing the energy to be required at a time for which energy is not consumed; and a boosting type sine wave converter 22 having a current limiting function with which charging is possible to the energy storage apparatus 23 at the maximum voltage allowed by the energy storage apparatus 23 and further at the maximum power allowed by a power equipment capacity. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention is an electric motor drive device that intermittently consumes energy, such as a press machine or an injection molding machine, and is capable of storing energy at a sufficiently high voltage and at the maximum power allowed by the power supply equipment in a time when the power energy is not consumed. The present invention relates to an intermittent load drive motor control device including a step-up sine wave converter having a constant current function so as to be possible.

There have been proposals relating to a method of driving a mechanical device that intermittently consumes energy, such as a press machine or an injection molding machine, with an electric motor.
JP 2007-331023 A JP 2004-344946 A JP 2004-74275 A JP 2003-290998 A JP 2000-141440 A

In these conventional cases,
1. It was necessary to generate an energy consumption prediction signal from a complicated operation pattern and operate the DC power supply circuit.
2. Since the DC voltage rises abnormally due to the regenerative energy surplus at the fixed point of the machine or emergency stop, the regenerative energy exceeding the capacity of the energy storage facility could not be absorbed by the DC power supply.
Or the device for reducing regenerative energy was required.
3. A step-up transformer was required in the AC power supply unit to secure the amount of stored energy.
4. Since the current limit is added on the DC side, the DC side voltage is greatly changed by the intermittent load, and the fluctuation of the input power is increased, resulting in a trouble in convenience of use.

This invention was made | formed with respect to the said subject, The objective is to obtain the following effects.
1. The energy consumption prediction signal is not required, and the energy of the DC power supply circuit can be freely transferred to the motor side or the AC power supply side at any time.
In addition, the energy storage device can be charged with the maximum current allowed by the capacity of the AC power supply equipment, and the maximum capacity press machine and injection molding machine can be operated with the minimum power supply equipment. .
2. The surplus energy in the DC power supply can be regenerated at any time to the AC power supply, contributing to energy savings and improving the capacity of presses and injection molding machines.
3, The DC voltage can be set freely to the maximum voltage allowed by the converter, inverter or DC energy storage device by using a step-up regenerative converter, without the need for a step-up transformer on the AC side. In addition, maximum energy storage is possible.
Moreover, since energy is exchanged with a sinusoidal current, harmonics can be suppressed and the power factor can be improved.
4. Since current limitation is applied on the AC side, fluctuations in the received power applied to the input can be reduced if the AC grid voltage is almost constant.

  According to the first aspect of the present invention, in an electric motor drive device of a press machine or an injection molding machine that consumes energy intermittently, an energy storage device that stores necessary energy at a time when energy is not consumed, and the energy storage device An intermittent load driving motor control device comprising a step-up sine wave converter having a current limiting function so that charging can be performed at a sufficiently high voltage and at a maximum power allowed by the capacity of a power supply facility.

The present invention has the following effects.
1. The maximum capacity press machine and injection molding machine can be operated with the minimum necessary power supply equipment.
2. In addition, the DC voltage can be set to the maximum value allowed by the device, and the capabilities of the press and injection molding machine can be further improved.
3. In addition, the regenerative energy generated when the press machine or injection molding machine is stopped at a fixed position or during an emergency stop is used to regenerate surplus energy that cannot be absorbed by the energy storage device to the AC side, thereby preventing the device from shutting down. Contribute to energy saving.
4.Since the energy is transferred to the power source with a sine wave current, it is possible to operate at the highest power factor while suppressing the generation of harmonics, and to operate at the maximum power supply capacity. is there.
5. It is possible to suppress the fluctuation of input power and operate with a stable power value.

  In an electric motor drive device that consumes energy intermittently, an AC-DC power converter is provided with a step-up sine wave converter and stores the obtained DC power, and this DC power is guided to the motor. Provided is a control device that includes an inverter device in a direct current to alternating current power conversion unit and minimizes the capacity of a power storage capacitor and the capacity of a power storage capacitor with respect to the required work of an intermittent load.

  Embodiments of the present invention will be described below with reference to FIGS.

FIG. 2 shows a typical press machine having an intermittent load.
Here, the example applied to the crank press as a press machine is shown.
A main gear 4 is meshed with a gear 3 connected to an output shaft 2 of the electric motor 1, and a crankshaft 5 and a connecting rod 6 are connected to the main gear 4. A slide 7 is connected to the tip of the connecting rod, and the slide 7 moves up and down with respect to the stationary bolster 8 by a crank mechanism.
Some slides 7 are provided with an air cylinder damper 9 for reducing regenerative energy.

A variable speed electric motor is used as the electric motor for driving the crankshaft 5, and forward / reverse rotation and speed change can be freely performed. Therefore, free press motion can be obtained.
A DC motor or an AC motor is used as the motor.

FIG. 3 shows a conventionally used system.
The AC power supply 11 is connected to the step-up transformer 12, and the DC power obtained by the rectifier circuit 13 is stored in the energy storage capacitor 16 by the capacitor 14 and the DC / DC chopper 15.
The inverter 17 operates the electric motor 18 using the DC power thus obtained.
However, the DC voltage changes according to the work of the press machine or the injection molding machine, so that the AC current from the power supply equipment changes greatly, and it is necessary to control a complicated DC / DC chopper.
In addition, depending on the voltage specifications and the capacity of the AC power supply equipment, it is necessary to select a step-up transformer. Furthermore, there are cases where it is difficult to operate a press or an injection molding machine with the maximum equipment capacity.

FIG. 1 shows a block diagram of the present invention.
The AC power supply 21 is connected to the step-up sine wave converter 22, and the obtained DC power is stored in the capacitor 23. The inverter 24 operates the electric motor 25 using the DC power obtained in this way.
If comprised in this way, even if a direct current voltage changes according to the work volume of a press machine or an injection molding machine, the alternating current from a power supply equipment can be charged / discharged with the maximum value of equipment capacity.
In other words, the maximum capacity of the AC power supply or the minimum necessary capacity of the AC power supply can be exhibited and the capacity of the maximum press machine or injection molding machine can be exhibited.
Further, the step-up transformer 12 and the air cylinder damper 9 for absorbing regenerative energy are not required.
Furthermore, since the DC voltage can be set freely, a large amount of power can be stored, which contributes to the reduction of the capacitor capacity.
In addition, the energy required for the work load of the press and injection molding machine can be supplied not only by the power storage device but also by the maximum value of the AC power supply equipment, which further increases the capacity of the press machine and injection molding machine. Contribute.

According to the present invention, in the electric motor driving apparatus that consumes energy intermittently, the following functions and effects are exhibited, which contributes to the convenience of use operation.
1. The energy consumption prediction signal is not required, and the energy of the DC power supply circuit can be freely transferred to the motor side or the AC power supply side at any time.
In addition, the energy storage device can be charged with the maximum current allowed by the capacity of the AC power supply equipment, and the maximum capacity press machine and injection molding machine can be operated with the minimum power supply equipment. .
2. The surplus energy in the DC power supply can be regenerated at any time to the AC power supply, contributing to energy savings and improving the capacity of presses and injection molding machines.
3, The DC voltage can be set freely to the maximum voltage allowed by the converter, inverter or DC energy storage device by using a step-up regenerative converter, without the need for a step-up transformer on the AC side. In addition, maximum energy storage is possible.
Moreover, since energy is exchanged with a sinusoidal current, harmonics can be suppressed and the power factor can be improved.
4. Since the current limit is applied on the AC side, fluctuations in the received power applied to the input can be reduced if the AC system voltage is substantially constant.

The block diagram of this invention is shown. An example of a typical press with intermittent load is shown. It is a system that has been used in the past

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Output shaft 3 Gear 4 Main gear 5 Crankshaft 6 Connecting rod 7 Slide 8 Bolster 9 Air cylinder damper 11 AC power source 12 Step-up transformer 13 Rectifier circuit 14 Capacitor 15 DC / DC chopper 16 Energy storage capacitor 17 Inverter 18 Electric motor 21 AC power source 22 Boost type sine wave converter 23 Capacitor 24 Inverter 25 Electric motor

Claims (1)

  In an electric motor drive device of a press machine or an injection molding machine that consumes energy intermittently, an energy storage device that stores necessary energy in a time that does not consume energy, and a maximum voltage that the energy storage device allows in the energy storage device, In addition, there is provided a step-up sine wave converter having a current limiting function capable of charging with the maximum power allowed by the power supply facility capacity, and an intermittent load driving motor control device.

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