JPS626438B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a power supply side thyristor converter that converts AC voltage to DC voltage, and a power supply side thyristor converter that converts the DC voltage obtained by the power supply side thyristor converter into AC voltage. A motor-side thyristor converter that detects the motor, a motor to which the AC voltage obtained by the motor-side thyristor converter is supplied, a motor rotation position detector that detects the rotor position of this motor, and a speed setting value and the actual motor a speed regulator that outputs a current command value according to the deviation from a voltage proportional to the speed; a current regulator that outputs a firing phase command value of the thyristor converter; a firing angle regulator that supplies a pulse signal according to the firing phase command value to the power supply side thyristor converter; and a motor rotation position detector. a pulse distributor that generates a pulse signal for making the thyristor of the thyristor converter on the motor side conductive in response to a motor rotational position detection signal of the motor; The present invention relates to a DC type non-commutator motor control system that performs speed control by controlling the firing angle of the power supply side thyristor converter to change the DC voltage supplied to the motor side thyristor converter.

[Conventional technology]

FIG. 1 is a schematic diagram of a generally known direct current type non-commutator motor control system. In this Figure 1, 1 is a power supply side thyristor converter that converts AC voltage to DC voltage and acts as a DC power supply, 2 is a DC reactor that smoothes the output DC voltage of this power supply side thyristor converter 1, and 3 is a power supply side thyristor converter. A motor-side thyristor converter converts the DC voltage obtained by the thyristor converter into an AC voltage, and 4 is a motor to which the AC voltage obtained by the motor-side thyristor converter 3 is supplied.

5 is a motor rotational position detector that detects the rotor position of the motor 4; 6 is a speed generator that generates a voltage proportional to the actual speed of the motor 4;

7 is a speed regulator that is supplied with a speed setting value and a voltage proportional to the actual speed of the motor 4 obtained by the speed generator 6, and outputs a current command value according to the deviation; 8 is a power supply side thyristor conversion A current detector 9 detects the actual current value of the converter 1, and a current detector 9 is supplied with the actual current value and the current command value of the speed regulator 7, and determines the firing phase command value of the power supply side thyristor converter 1 according to the current deviation. 10 is a firing angle regulator for supplying a pulse signal corresponding to this firing phase command value to the power supply side thyristor converter 1; 11 is a firing angle regulator that amplifies the pulse signal and transmits it to the power supply side thyristor converter 1; This is a pulse amplifier that supplies the converter 1.

12 is a switching command calculator that determines the required torque direction (forward rotation, reverse rotation) of the motor according to the output voltage polarity of the speed regulator 7; 13 is a motor rotation position detector 5;
A pulse distributor generates a pulse signal for making the thyristor of the motor-side thyristor converter 3 conductive in accordance with the motor rotation position detection signal; 14 is a pulse distributor that amplifies the pulse signal and supplies the pulse signal to the motor-side thyristor converter 3; It's an amplifier.

Very simply, the operation of the system of FIG. By controlling the firing angle of the power supply side thyristor converter 1 through the current regulator 9 and firing angle regulator 10, the DC supply voltage to the motor side thyristor converter 3 is changed to perform speed control. . There are two series of ignition pulses for the motor-side thyristor converter 3, one for forward rotation torque and one for reverse rotation torque, and the switching command calculator 12 controls the ignition pulses of the motor according to the output voltage polarity of the speed regulator 7. The required torque direction is determined and one of these two series is sent to the pulse distributor 13.
Add to. In this pulse distributor 13, based on this torque direction signal, the motor rotation position detector 5
A pulse signal for selectively conducting the thyristor of the motor-side thyristor converter 3 is applied to the motor-side thyristor converter 3 via the pulse amplifier 14 in response to a position detection signal from the motor side thyristor converter 3 .

[Problem that the invention seeks to solve]

A DC non-commutator motor differs from an AC non-commutator motor using a cycloconverter in that it has a thyristor converter on the power supply side and a thyristor converter on the motor side. The motor-side thyristor converter commutates at the motor frequency. In such a DC type non-commutator motor,
Maximum current value when selecting a thyristor for the motor side thyristor converter (output limit value of speed regulator 7)
It is necessary to consider the commutation frequency, and in addition to considering the commutation frequency at the rated rotation of the motor, it is necessary to consider the commutation frequency during the acceleration period from a stopped state of the motor and from the rated rotation state. The capacity of the thyristor must be determined by taking into account the temperature rise during the deceleration period and during each flow time of the thyristor. In a system where the thyristor of the thyristor converter on the motor side is selected as described above, if the motor does not start rotating despite the speed setting value being non-zero for some reason, the motor rotor Two specific thyristors in the thyristor converter on the motor side, which are determined by the position, become in a continuous state of conduction, and the temperature of the junction in the thyristor element exceeds the permissible temperature and is destroyed. To prevent this, the capacity of the thyristor of the thyristor converter on the motor side could be selected to allow continuous flow at the maximum current value, but this would be extremely uneconomical.

An object of the present invention is to provide a DC non-commutator that can detect when the rotor does not start rotating and prevent the thyristor from being destroyed due to continuous flow, without the need to increase the capacity of the thyristor of the converter on the motor side. The purpose of the present invention is to provide an electric motor control system.

[Means for solving problems]

In order to achieve such an objective, the present invention
an actual speed value detector for detecting an actual speed value of the motor; a speed set value detector for detecting a speed set value;
When the detected speed setting value is not zero when starting the motor, and the detected speed actual value continues to be zero for a preset time or more, the power supply side thyristor converter is set to be in the inverse conversion operation region. A firing angle shift command generating device is provided to perform an arc angle shift, and when the actual detected speed value continues to be zero for a preset time or more when the detected speed setting value is not zero when starting the motor. is characterized in that a reverse voltage is generated in the power supply side thyristor converter.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows a main part of an embodiment of the present invention. In FIG. 2, 15 is an actual speed value detector that detects the actual speed value of the motor 4, 16 is a speed setting value detector that detects the speed setting value, and 17 is a state in which the detected speed setting value is not zero when the motor is started. When the detected actual speed value continues to be zero for a preset time or more, the firing angle shift command is issued to shift the firing angle so that the power supply side thyristor converter 1 is in the inverse conversion operation region. It is a generator. The firing angle shift command generating device 17 includes an AND element 18 and a negative element 1
9 and a timer 20. Other components shown in FIG. 2 are similar to those shown in FIG. 1 and are designated with the same reference numerals.

The speed set value detector 16 generates a logic signal of "1" when the speed set value is not zero, and similarly, the speed actual value detector 15 generates a logic signal of "1" when the speed actual value is not zero.
outputs a logical signal. Therefore, AND element 18 outputs a logic signal of "1" only when the actual speed value is zero even though the speed set value has a value other than zero. The timer 20 outputs a logic signal of "1" when a logic signal of "1" is continuously inputted for more than the set time of the timer, and immediately outputs "0" when the input becomes a "0" signal. It becomes a signal. When the output of the timer 20 is a "1" signal, this signal shifts the firing angle of the power supply side thyristor converter 1 so that the power supply side thyristor converter 1 is in an operating state for converting from DC to AC. The arc angle shift command is given to the current regulator 9 through the switching command calculator 12. The output of the timer 20 becomes "1" only when the speed setting value is not zero and the actual speed value continues to be zero for more than the time set by the timer 20. Therefore,
If the setting time of the timer 20 is set longer than the maximum time during which the first thyristor pair can flow in the predetermined starting acceleration time of the motor 4, but shorter than the time that the thyristors can allow in continuous flow, the motor can operate at the predetermined speed. When starting acceleration is not performed, the firing angle of the power supply side thyristor converter 1 is shifted to a predetermined minimum control advance angle γmin, and power is no longer supplied to the electric motor 4. That is, since the thyristor of the motor-side thyristor converter 3 does not conduct continuous current beyond the set time of the timer 20, the thyristor is protected even if the motor 4 does not start for some reason.

〔Effect of the invention〕

As explained above, in the present invention, even though a speed setting value is given at the time of starting the electric motor,
If the electric motor 4 does not rotate for some reason,
This was done in consideration of the fact that the two thyristors of the motor-side thyristor converter 3 corresponding to the rotation stop position of the motor 4 are in a continuous conduction state and current continues to flow, resulting in destruction.

Therefore, in the present invention, when the speed setting value is given and the output signal of the speed generator 6 is not continuously generated for a certain period of time, the power supply side thyristor converter 1 is reversed. The conversion operation is performed to generate a reverse voltage, which is applied to the motor-side thyristor converter 3, whereby the thyristor of the motor-side thyristor converter 3 is cut off in a short time and protected.

Therefore, according to the present invention, it is possible to prevent the thyristor from being destroyed when starting the motor without increasing the capacity of the thyristor of the motor-side thyristor converter 3.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a known DC type non-commutator motor system, and FIG. 2 is a diagram showing an embodiment of the present invention. 1: Power supply side thyristor converter, 3: Motor side thyristor converter, 4: Electric motor, 6: Speed detection alternator, 7: Speed regulator, 8: Current detector,
9: Current regulator, 10: Firing angle regulator, 11: Pulse amplifier, 12: Switching command calculator, 13: Pulse distributor, 14: Pulse amplifier, 15: Speed actual value detector, 16: Speed setting value Detector, 17: Firing angle shift command generator, 18: AND element, 1
9: negative element, 20: timer.

Claims (1)

[Claims] 1. A power supply side thyristor converter 1 that converts an alternating current voltage into a direct current voltage, a motor side thyristor converter 3 that converts the direct current voltage obtained by this power supply side thyristor converter into an alternating current voltage, and this A motor 4 to which the AC voltage obtained by the motor-side thyristor converter is supplied.
, a motor rotational position detector 5 that detects the rotor position of the motor, a speed regulator 7 that outputs a current command value according to the deviation between the speed setting value and a voltage proportional to the actual speed of the motor; A current regulator 9 that outputs a firing phase command value of the power supply side thyristor converter according to a current deviation between an actual current value of the power supply side thyristor converter and a current command value of the speed regulator; a firing angle regulator 10 that supplies a pulse signal according to the value to the power supply side thyristor converter;
and a pulse distributor 13 that generates a pulse signal for making the thyristor of the motor-side thyristor converter conductive in accordance with the motor rotation position detection signal of the motor rotation position detector, and a pulse distributor 13 that generates a pulse signal for making the thyristor of the motor-side thyristor converter conductive in accordance with the motor rotation position detection signal of the motor rotation position detector. A DC type non-commutator that controls the speed by changing the DC voltage supplied to the motor side thyristor converter by controlling the firing angle of the power supply side thyristor converter according to the deviation from the speed detection value. In the motor control system, an actual speed value detector 15 detects the actual speed value of the motor, a speed set value detector 16 detects the speed set value, and a speed set value detector 16 detects the speed set value when the motor is started, in a state where the detected speed set value is not zero. A firing angle shift command generating device that shifts the firing angle so that the power supply side thyristor converter is in a reverse conversion operation region when the detected speed actual value continues to be zero for a preset time or more. 17, which generates a reverse voltage in the power supply side thyristor converter when the detected speed actual value continues to be zero for a preset time or more in a state where the detected speed set value is not zero when starting the motor. A DC commutatorless motor control system characterized by: