JP2000116190A - Method for controlling regenerative power of motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling the regenerative power of an inexpensive small motor controller, capable of being shared in various models of different power voltage specifications. SOLUTION: The voltage data of a converter 3 at the time of not energizing a motor are converted by an AD converter 7 to determine a criterion of setting a regenerative level. The criterion is compared with the AD-converted voltage data of a voltage monitoring means 6 monitoring the voltage of the converter 3 using a comparison means 10. If it is in a regenerative mode exceeding the criterion, it is multiplied by a coefficient 14 proportional to the regenerative power and added to a register counter 13, and the regenerative power is consumed by a regenerative consuming means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative power control method for a motor control device used for a drive source of industrial equipment or the like.

[0002]

2. Description of the Related Art Conventionally, regenerative power control of a motor control device is performed when a voltage of a converter exceeds a reference value to be compared.
The regenerative transistor is turned on, a current flows through the regenerative resistor, and the regenerative power is consumed.

In FIG. 4, reference numeral 22 denotes a comparator for comparing the voltage of the converter unit 25 with a fixed comparison value 21;
Reference numeral 23 denotes a transistor which is turned on / off by the output of the comparator 22. Reference numeral 24 denotes a regenerative resistor which consumes regenerative power by the transistor 23. The DC voltage of the converter 25 is applied to the inverter 26, and the motor 27 is powered by the PWM drive signal. Is supplied. When the voltage of the converter unit 25 exceeds the comparison value 21, the transistor 23 is turned on,
The regenerative current flows into the regenerative resistor 24, and the regenerative power is consumed by the regenerative resistor 24.

[0004]

However, in the above-described conventional configuration, the comparison value is a fixed value determined by the resistance value of the resistor mounted on the printed circuit board. Had to be changed.

[0005] Further, since the regenerative power consumption is performed when the power consumption exceeds a certain limit value, it is necessary to ensure the reliability at the maximum load when selecting the regenerative resistor. As a result, the motor control device is increased in size and cost is increased.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small and inexpensive regenerative power control method for a motor control device that can be shared by models having different power supply voltage specifications.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a step of converting a monitored voltage of a converter section into a digital value, and taking the output converted into the digital value into a CPU to control regenerative power. The reference voltage for setting the regenerative level by AD-converting the voltage of the converter unit when the motor is not energized, and comparing this reference value with the voltage of the AD-converted converter unit when the motor is energized. In the case of the regenerative mode exceeding the reference value, a value proportional to the regenerative power is incremented, and in the case of the powering mode equal to or less than the reference value, the counter proportional to the powering power is decremented. Since the regenerative electric power is consumed by the regenerative consuming means, the replacement of parts for each model can be eliminated, and an increase in the size of the regenerative resistor and an increase in cost can be suppressed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention monitors the voltage of a converter section and determines whether the mode is a regenerative mode exceeding the input of the converter section or a powering mode which is not so. A step of converting the monitored voltage information of the converter unit into a digital value in the motor control device for consuming the regenerative power, if any, and a step of taking the output converted into the digital value into the CPU and executing the regenerative power control The reference for setting the regenerative level by AD-converting the voltage information of the converter unit when the motor is not energized is determined, and this reference value is compared with the AD-converted voltage of the converter unit when the motor is energized by comparison means. If the regenerative mode exceeds the reference value, the value proportional to the regenerative power is incremented, and if the regenerative mode is equal to or less than the reference value,
This is a regenerative power control method for a motor control device in which regenerative power is consumed by regenerative consuming means with a counter value that decrements in proportion to the powering power.

A regenerative power control method for a motor control device according to claim 1, wherein the AD-converted value is stored in a non-volatile storage means at predetermined time intervals.

The regenerative power control method for a motor control device according to claim 1, wherein the value of the counter is stored in the non-volatile storage means at regular intervals.

In this manner, the reference for setting the regeneration level is determined from the voltage information of the converter unit when the motor is not energized, and compared with the AD converted voltage information when the motor is energized, the regenerative mode or the powering mode is determined. Is determined by the CPU,
The regenerative power consumption in the regenerative mode can be controlled.

Further, by storing the AD-converted value at regular intervals, it is possible to specify the change in the regenerative load and the time during which the maximum regenerative power is generated.

Further, by storing the value of the counter at regular intervals, a change in the regenerative load factor can be specified.

Thus, even in models having different power supply voltage specifications, the regenerative level is determined by the CPU, so that parts replacement for each model can be eliminated, and the regenerative load factor and the maximum regenerative power can be controlled by the CPU. In addition, it is possible to increase the size and cost of the regenerative resistor selected according to the maximum regenerative load. Further, it can be used for optimal design such as miniaturization and energy saving of the user's machine.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, 1 is a diode bridge, 2 is a smoothing capacitor, 3 is a converter,
4 is an inverter unit, 5 is a motor, 6 is voltage monitoring means, 7
Is an AD converter, 8 is a CPU, 9 is software of the CPU, 10 is a comparing means, 11 is a regenerative consuming means, 12 is a register, 13 is a register counter, and 14 and 15 are coefficients.

Next, the operation will be described. The converter rectified by the current rectified by the diode bridge 1 charges the smoothing capacitor 2, and the DC voltage of the converter 3 is applied to the inverter 4. P
The power is supplied to the winding of the motor 5 after the WM conversion.

First, after the voltage of the converter section 3 has reached a steady state, a reference for the regenerative level is set from the voltage information of the converter section 3 in which the motor is not energized, ie, stopped. That is, the reference of the regeneration level is set by converting the voltage of the voltage monitoring means 6 into a digital value by the AD converter 7 and storing it in the register 12. The voltage monitoring means 6 also monitors the voltage of the converter unit 3 when the motor is energized. The voltage monitoring means 6 is generally divided by a resistor, and a minute voltage proportional to the voltage of the converter unit 3 is input to the AD converter 7 of the comparison means 10. The voltage information of the converter unit 3 input to the AD converter 7 and converted into a digital value is input to the CPU 8,
The processing is performed by software 9 of the CPU 8. The operation of the software 9 will be described with reference to FIG.

In step 16, the software 9 compares the voltage information of the converter unit 3 when the motor is energized, that is, in the operating state, with the value (reference value) of the register 12 which is the voltage information when the motor is not energized. In the regenerative mode, the difference is multiplied by a coefficient 14 in step 17 and added to the register counter 13. In the following powering mode, the difference is multiplied by a coefficient 15 in step 18 and subtracted from the register counter 13. Further, in step 19, the energy consumption of the regenerative consuming means 11 is determined according to the energy capacity of the converter section 3, and the regenerative consuming means 11 is controlled.

The coefficients 14 and 15 are values calculated in advance so that the value of the register counter 13 becomes the integrated value of the regenerative energy returned to the converter 3. Further, since the voltage information of the converter unit 3 fluctuates due to variations in circuit constants, temperature drift, and the like, an appropriate dead zone is provided for the difference between the converter unit 3 and the register 12. The voltage monitoring means 6 includes a V / F converter and an F / V converter, which are combined and insulated to place the AD converter 7 on the secondary side, or to place the AD converter 7 on the primary side to form a serial interface. There are methods such as insulation using a photocoupler, and a method in which the AD converter 7 is placed on the primary side and used as a parallel interface to achieve both insulation and high-speed interface by capacitor coupling.

Further, it is needless to say that the voltage information of the converter section 3 obtained here is a value which largely depends on the accuracy and the responsiveness of the voltage monitoring means 6 and the AD converter 7. The accuracy and responsiveness of the voltage monitoring means 6 and the AD converter 7 are based on the premise that the voltage monitoring means 6 and the AD converter have sufficient accuracy and responsiveness to monitor the regenerative energy fluctuation of the motor.

As described above, the software of the CPU is burned into a non-volatile storage element such as a ROM or a flash ROM on the board. Regenerative power control according to the constant can be easily realized.

(Embodiment 2) In FIG. 3, a converter 3, an inverter 4, a motor 5, a voltage monitoring means 6, an AD
The converter 7, the CPU 8, and the regenerative consuming means 11 are the same as in the first embodiment. The voltage information of the converter unit 3 input to the AD converter 7 is input to the CPU 8 and stored in the non-volatile storage means 20, for example, a FLASH memory or an EEPROM at regular intervals by the software 9 of the CPU 8.

Similarly, the value of the register counter 13 of the first embodiment can be stored in the non-volatile storage means 20 at regular intervals.

In general, the number of times of writing in the nonvolatile storage means 20 is limited to several hundred times in the FLASH memory and to several hundred thousand times in the EEPROM, so that the write data is temporarily stored in the register or the RAM and is temporarily stored in the nonvolatile storage means 20. A device is devised to reduce the number of times of writing to the memory. When the storage capacity of the non-volatile storage unit 20 is small, it is possible to store only the voltage of the converter unit 3 or the peak value of the register counter 13.

As described above, by storing the AD-converted value in the non-volatile memory at regular intervals, it is possible to easily specify the change in the regenerative load and the time during which the maximum regenerative power is generated in the tact of the device. In addition, miniaturization and energy saving of the device can be realized. Also, if the counter value is stored in a non-volatile memory at regular intervals, the change in the regenerative load factor can be specified, and the motor control device can be downsized by incorporating the minimum necessary regenerative consumption means. it can.

[0027]

As is apparent from the above embodiment, according to the first aspect of the present invention, the regeneration level is determined by the CPU even in the models having different power supply voltage specifications, so that the exchange for each model can be eliminated. In addition, it is possible to increase the size and cost of the regenerative resistor selected according to the maximum regenerative load.

According to the second aspect of the present invention, it is possible to easily specify the change in regenerative load and the time during which the maximum regenerative power is generated in the tact of the device, thereby reducing the size and energy saving of the device. Can be realized.

Further, according to the third aspect of the present invention, the change in the regenerative load factor can be easily specified, and the motor control device can be downsized by incorporating the minimum necessary regenerative processing means. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram of regenerative power control according to a first embodiment of the present invention.

FIG. 2 is a flowchart of software of a CPU according to the first embodiment of the present invention.

FIG. 3 is a block diagram of regenerative power control according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a conventional regenerative power control.

[Explanation of symbols]

 Reference Signs List 3 converter unit 5 motor 6 voltage monitoring means 7 AD converter 8 CPU 10 comparing means 11 regenerative consuming means 12 register 13 register counter 14, 15 coefficient 20 nonvolatile storage means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H530 AA02 BB40 CC18 CC30 CD34 CE15 DD03 EE01 EF04 GG01 GG07 GG08 5H576 AA20 BB02 BB03 BB10 CC05 DD02 EE09 EE11 FF04 HB02 JJ03 JJ10 JJ12 JJ15 JJ16 JJ03 JJ03

Claims (3)

[Claims] 1. A motor control device that monitors a voltage of a converter unit to determine whether a regenerative mode exceeds an input of the converter unit or a powering mode that does not exceed the input of the converter unit. A step of converting the monitored voltage information of the converter section into a digital value, and a step of taking the output converted into the digital value into the CPU and executing regenerative power control, wherein the voltage information of the converter section when the motor is not energized is provided. Is determined by AD conversion to set a regeneration level, and this reference value is compared with the voltage of the AD-converted converter section when the motor is energized by comparing means. If the regeneration mode exceeds the reference value, the regeneration In the powering mode in which the value proportional to the power is incremented and the powering mode is equal to or less than the reference value, the value proportional to the powering power is decremented by the counter value decremented. A regenerative power control method for a motor control device in which power is consumed by regenerative consuming means. 2. The regenerative power control method for a motor control device according to claim 1, wherein the AD-converted value is stored in a non-volatile storage means at regular time intervals. 3. The regenerative power control method for a motor control device according to claim 1, wherein the value of the counter is stored in a non-volatile storage means at regular time intervals.