JP2727365B2 - Motor control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for controlling a speed using a DC motor.

[Conventional technology]

 A conventional motor control device is shown in FIG.

3 is a main circuit connection diagram, FIG. 4 is a block diagram, and FIG. 5 is a characteristic diagram. In FIGS. 3 and 4, 1 is a DC power supply and 2 is an electric motor of a DC series motor. Child winding,
3 is an armature current detector, 4 is a series winding field winding, 5 is a field current detector, 6 is a control rectifier circuit, and shows an example of a three-phase mixed bridge rectifier circuit 6a included in a freewheeling diode. I have. Reference numeral 7 denotes a separately-excited control power supply, which shows an example of three-phase alternating current. Reference numeral 8 denotes a main resistor, which is not shown, and is short-circuited sequentially controlled by a camshaft contactor. 9 is a shunt reactor, 10 is a contactor, 11 is an armature current pattern generator (hereinafter simply referred to as a pattern generator), 12 is an operational amplifier for an armature current control loop, and 13 is an operation for a field current control loop. In the amplifier, the field current control is configured as a minor loop, and the armature current control is configured and controlled as a major loop.

The operation is as follows. When the motor is started, the contactor 10 is kept open, and the main resistor 8 is kept with the gate of the control rectifier circuit 6 stopped.
Is set to the state of the maximum resistance value, and the motor is started as a series-wound motor by passing a starting current in an all-field state. The armature current is set to be maintained at a substantially constant value, and the motor accelerates while sequentially short-circuiting the main resistor 8 according to a certain current limit value. When all the main resistors 8 are short-circuited, the contactor 10 is closed, the gate of the control rectifier circuit 6 is opened, and the phase control is started. At this time, the pattern generator 11 generates the same current-limiting value as that during the resistance advance stage as the pattern value, and the operational amplifiers 12 and 13 start operating from the moment the contactor 10 is closed. When the operational amplifiers 12 and 13 are activated, they are activated from a state where the value of the armature current pattern and the detected value of the armature current (output of the armature current detector 3) are equal. The control of the output voltage of the circuit 6 starts from the lowest value. Therefore, when the contactor 10 is closed, the current flowing through the series-wound field winding 4 rapidly begins to shunt toward the shunt reactor 9 and becomes a weak field state (point A shown in FIG. 5, Normally, the internal resistance of the shunt reactor 9 is set to be much smaller than the internal resistance of the field winding 4 to enable the weak field control.) For this reason,
The armature current increases rapidly, whereby the output of the operational amplifier 12 is output as a field current pattern so as to increase the field current. As a result, the output of the operational amplifier 13 starts operating to increase the output voltage of the control rectifier circuit 6. When the output voltage of the control rectifier circuit 6 becomes sufficiently high by such a movement, the decrease of the field current finally stops (B in FIG. 5).
(Point) The armature current also starts to decrease. When the armature current becomes equal to the output of the armature current pattern generator 11 through such a process, the state becomes stable (point C in FIG. 5), and thereafter, as the motor speed increases, the armature current becomes higher. Is adjusted to match the output of the armature current pattern generator 11 to perform continuous field weakening control.

[Problems to be solved by the invention]

However, after all the main resistors 8 are short-circuited, the value of the armature current that jumps up when the contactor 10 is closed is large, and there is a possibility that the transient rectification may deteriorate for the motor.
An abrupt change in the torque generated by the motor may adversely affect the load.

The present invention has been made in view of the above points, and an object of the present invention is to provide a motor control device having improved characteristics and the like of a motor.

[Means for solving the problem]

In other words, means for achieving the object are supplied from the positive side of the DC power supply to the armature winding of the DC series motor, the series field winding of the DC series motor, and another AC power supply. A rectifier circuit with a bypass diode that outputs a variable DC voltage by phase-controlling the electric power, and a main resistor that variably controls the speed of the DC series motor with an increase in speed are connected in series to reach the negative electrode of the DC power supply. A speed control circuit is configured, and one end of a shunt reactor in which a shunt reactor and a contactor are connected in series is connected to a connection point between the armature winding and the series winding field winding, and the other contactor is connected. One end is connected to the connection point between the control rectifier circuit and the main resistor, the contactor is open at the time of startup, and the gate of the control rectifier circuit is stopped and according to a preset current limit value while the gate is stopped. Acceleration control by sequentially shorting the main resistors The contactor is closed after all the main resistors are short-circuited, and at the same time, the gate of the control rectifier circuit is opened, and the current flowing in the series winding field winding is shunted to the electric circuit on the shunt reactor side, thereby the electric motor is controlled. In a motor control device that controls the armature current to match a constant current pattern and continuously performs field weakening control, an armature current pattern reduction amount generator and a timer are used from the moment when the contactor is closed. The control is performed such that the value of the current pattern of the armature current is reduced during a certain time.

[Action]

The operation will be described together with the following embodiment.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a motor control device according to the present invention, and FIG. 2 is a characteristic diagram thereof. Those having the same reference numerals as in FIG. 4 are portions having the same configuration and function.

In FIG. 1, an armature current pattern reduction amount generator (hereinafter simply referred to as a pattern reduction amount generator) 14 of the present invention and a timer 15 are connected in parallel.
Are connected so that the output signal from is subtracted. The subtracted result is input to the operational amplifier 12 as an armature current pattern.

Next, these operations will be described with reference to FIG.

The control means according to the present invention has the same main circuit connection as that shown in FIG. 3, and performs acceleration control by short-circuiting the main resistor 8 while limiting the current as in the conventional control means.

Now, after all the main resistors 8 are short-circuited, the contactor 10 is closed, the control rectifier circuit 6 is activated, and at the same time, the operational amplifier 1 is closed.
2,13 are also activated. At this time, the pattern reduction amount generator 14 to which the interlocking contact signal of the contactor 10 has been input starts to generate an output, so the value input to the operational amplifier 12 as the armature current pattern is the pattern reduction from the output of the pattern generator 11. Since the output of the quantity generator 14 is subtracted,
It will be a small value. Therefore, the contactor 10 closes, the field current starts to shunt to the shunt reactor 9 and becomes a weak field state, and the armature current starts to increase (point A in FIG. 2). As described above, as the input of the operational amplifier 12, the actual armature current detection value becomes much larger than the armature current pattern, and the output of the operational amplifier 12 becomes large due to the large deviation. The pattern is outputted so as to become a stronger field current earlier than the case shown in FIG.

Similarly, in the operational amplifier 13, since the field current pattern becomes larger quickly than the actual field current detection value, the deviation also becomes larger, and the output voltage of the control rectifier circuit 6 as an output is changed as shown in FIG. Start the operation to raise faster than compared. For this reason, the weakening of the field current becomes pure, and the increasing of the armature current also becomes slow. Therefore, the increase in the armature current stops quickly (point B in FIG. 2).
The armature current starts to decrease. During this time, if the output of the timer 15 that counts the time from the turning on of the contactor 10 counts up as an appropriate value (until point C in FIG. 2), the output of the pattern reduction amount generator 14 is cut off. The output value of the pattern generator 11 returns to the armature current pattern.

In this way, the armature current becomes stable when it becomes equal to the output of the armature current pattern generator 11 (point C in FIG. 2). The output of the control rectifier circuit 6 is adjusted to match the output of the heater 11.

〔The invention's effect〕

As described above, according to the present invention, when the contactor 10 is closed after all of the main resistors 8 are short-circuited, the value of the jumping armature current is suppressed to a low value, and the commutation of the motor does not deteriorate. Can be controlled without the sudden change of torque.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a characteristic diagram thereof, FIG. 3 is a main circuit diagram, FIG. 4 is a block diagram of a conventional device, and FIG. is there. 1 ... DC power supply, 2 ... armature winding, 3 ... armature current detector, 4 ... series wound field winding, 5 ... field current detector,
6: Control rectifier circuit, 7: Separately-excited control power supply, 8: Main resistor, 9: Shunt reactor, 10: Contactor, 11: Pattern generator, 12, 13: Operational amplifier, 14… Pattern lowering amount generator, 15… Timer.

Claims (1)

(57) [Claims] 1. A phase control of an armature winding of a DC series motor, a series winding field winding of the DC series motor, and power supplied from another AC power source from the positive side of the DC power source. A control rectifier circuit with a bypass diode that outputs a variable DC voltage, and a main resistor that variably controls the speed of the DC series motor as the speed increases, constitute a speed control circuit that reaches the negative electrode of the DC power supply. One end of a shunt reactor in which a shunt reactor and a contactor are connected in series is connected to a connection point between the armature winding and the series winding, and one end of the other contactor is connected to the control rectifier circuit. And the main resistor, the contactor is opened at the time of starting, the gate of the control rectifier circuit is stopped, and the main resistor is sequentially turned on according to a preset current limiting value. Short-circuit and accelerate control, all main resistors are short-circuited Later, at the same time as closing the contactor, the gate of the control rectifier circuit is opened, and the current flowing in the series-wound field winding is shunted to the shunt reactor-side electric circuit so that the armature current matches a certain current pattern. In the motor control device, the armature current pattern reduction amount generator and the timer control the armature current for a certain period of time from the moment when the contactor is closed, by controlling the field weakening control so as to continuously perform the field weakening control. A motor control device that controls so as to reduce the value of the current pattern.