JPS59220087A - Set control leading angle controlling method for commutatorless motor - Google Patents

Abstract

PURPOSE:To enable to reduce the induced voltage without weakening a motor field by varying a set control leading angle when a power source side phase angle reaches the prescribed value. CONSTITUTION:A speed controller 6 outputs a phase control angle command signal in response to a deviation between a speed command signal by a speed setter 5 and a speed returning signal of a speed detector 4, and a phase controller 7 outputs a gate command signal to a gate controller 8 in response to a phase control angle command signal. A set control leading angle controller 10 inputs a detection signal which shows the fact that a signal which indicates the power drive state and the regenerative state from a power drive regenerative discriminator 9 and a phase control angle command signal from a phase angle detector 12 reach the set value, and when the detection signal is inputted in a regenerative region, the maximum set control leading angle is outputted and when the detection signal is inputted, the set control leading angle of small value reduced effectively is outputted to the controller 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a non-commutator motor, and more particularly to an improvement in a setting control and advance angle control method for a non-commutator motor that can realize high regenerative torque control.

In general, when driving a synchronous motor using a power converter consisting of a plurality of switching elements, that is, when driving a non-commutator motor, it is theoretically necessary to advance the set control advance angle in the high-speed region to around 180' in order to prevent overcurrent. I can't. The reason for this is that when the rotational energy of the motor is regenerated to the power supply side, the voltage on the power supply side does not rise to the voltage corresponding to the induced voltage of the motor, which prevents overcurrent from being induced. It is. For this reason, a method is usually adopted in which the rotational speed of the electric motor is detected and the set control advance angle is changed according to the speed range. Then, for example, the set control advance angle is set to i20' in the high speed range and approximately 180' in the low speed range, and the isolateral advance electromotive force seen from the power converter side of the motor increases excessively even in the high speed range. I was avoiding it.

However, in the conventional method of determining the set control advance angle by detecting the rotation speed of the motor, it is required to clarify the correlation between the motor rotation speed, the set control advance angle, and the induced voltage. However, it is extremely difficult to determine this unambiguously. One example of the reason for this is that the generation coefficient of induced voltage caused by the manufacture of the motor is <2. In addition, near the speed at which the set control advance angle is switched, the set control advance angle is not sufficiently advanced in a region where the set control advance content is small, so the amount of regenerative torque is suppressed, resulting in a decrease in utilization efficiency. It was supposed to have a A typical device for this conventional method is shown in FIG.

FIG. 1 is a block diagram showing the configuration of the main parts of a non-commutator motor control device according to Conventional Example 1, in which 1 is an AC power supply, 2 is a cycloconverter section, and 3 is a synchronizer'! ! Motive, 4 is speed detector,
5 is a speed setting device, 6 is a speed control circuit, 7 is a phase control circuit, 8 is a gate control circuit, 9 is a regeneration discrimination circuit, 10 is a setting control advance angle control circuit, and 11 is a speed region discrimination circuit.

That is, in such a circuit configuration, the cycloconverter section 2 that energizes the synchronous motor 3 from the input power of the AC power source 1 is an element that performs a switching operation from the gate control circuit 8 at the final output stage of the control circuit section. It is used to obtain control commands for parts. This is because the speed feedback signal from the speed setter 5I and the speed feedback signal from the speed detector 4 are given to the speed control circuit 6, and the phase control angle command signal is generated from the calculation example of PID adjustment by the speed control circuit 6. The phase control circuit 7 synchronizes with the power supply and provides a gate command signal at a timing corresponding to the phase control angle.

A detailed explanation of the gate control circuit 8 will be omitted here, but the switching of the cycloconverter section 2 is based on the rotor position signal 4 of the synchronous motor 3, which is obtained by calculation from input signals such as a distributor and armature back electromotive force. It has a logic circuit section that selects an element and a switching element drive circuit section, and sends a control command to drive the selected switching element to the cycloconverter section 2.

Furthermore, the setting control advance angle control circuit 10 uses a signal indicating the power travel state/regeneration state obtained from the power travel regeneration determination circuit 9 and a signal representing the speed region state that reveals the speed region obtained from the speed region determination circuit 11. Determine the setting control advance angle,
The setting command is given to the gate control circuit 8. It should be noted that the determination of power regeneration can be easily obtained by determining the calculation result of the speed control circuit 6, for example, from the magnitude relationship between the command signal and the speed signal.

Here, assuming that the voltage induced at the motor terminals is VM and the internal induced voltage is BM, and ignoring the voltage drop due to the internal resistance, it is known that the following relationship holds true.

VM QCEM @Q)11 (βo −) 1tm
-・-(1)2 However, βO is the setting control advance angle, and μ is the overlap angle.

In the first regeneration region, the setting control advance angle β0 is 18
Although it is controlled in the range of 0' to 90', the larger the value of β0, the larger the value of the voltage vM. Na.

Note that the value of the overlap angle μ depends on the load current.

Furthermore, it is well known that the following relationship holds true for the power supplied to the synchronous motor 3I from the power supply voltage V8+phase control angle α.

VM CX: VB-■α ・・・・・・・・・
(2) In this way, when the voltage vM increases with an increase in the set control advance angle β0, it is necessary to increase the power supply voltage Vs or decrease the phase control angle α according to equation (2). However, the power supply voltage Vs usually cannot be changed freely6. In addition, '(cosa) (here, when the phase control angle a is advanced, it cannot be reduced by more than (-1). Therefore, if the phase control angle α advances to around 180', it will match the voltage vM found by equation (2). becomes impossible.

This means that control to return the rotational energy of the electric motor to the power source side becomes impossible, which indicates that excessive current is induced. Note that field weakening, which reduces the field current of the motor, is used as a general method for suppressing the induced voltage of the motor. However, this method causes problems such as a decrease in output torque, an increase in motor speed at light loads, a failure to reduce induced voltage, and a lack of stability in control operation.

The present invention has been made with attention to the above-mentioned points, and in order to reduce the induced voltage without weakening the motor field, the set control advance angle as shown in the relationship of equation (1) is set to a small value in the regeneration region. The present invention provides a special control method that allows for changes in

FIG. 2 is shown to facilitate understanding of the technical idea of the present invention, and shows a general configuration of a device similar to the device shown in FIG. 1, where lO' is a setting control advance angle control circuit. , 12 is a phase angle detection circuit.

In the figure, the same reference numerals as in FIG. 1 indicate parts having the same function.

That is, the device shown above is particularly equipped with a phase angle detection circuit 12 and a setting control advance angle circuit lO' which obtains the output of the phase angle detection circuit 12 and operates to effectively delay the setting control advance angle. It will be done. Here, the method of driving the synchronous motor 3 is as explained in FIG.
The phase control angle command signal detects that the phase control angle α has reached its limit and generates a signal to the setting control advance angle control circuit 10'. Therefore, when the phase angle detection circuit 12 generates a signal, for example, when the phase control angle α reaches around 180°, the setting control advance angle control circuit 10' changes the setting control advance angle command to lag behind around taO°. A signal is sent as a lead angle command. therefore,(
1) From the relationship of the formula, the setting control advance angle β0 is 1800 to 90
It becomes a small value that is effectively reduced within the range of ', and an increase in the induced voltage of the synchronous motor 3 can be suppressed.

It goes without saying that in normal times, that is, when the phase angle detection circuit 12 does not supply a signal, the maximum advance angle is set at around 180°.

Now, the torque of the electric motor is expressed as the product of the field magnetic flux ΦF and the armature magnetomotive force (zero) multiplied by the sine of the phase difference angle between the two, and the phase difference angle is (120'+βO) ~ (60' β
0), and at light loads where the overlap angle μ has no effect, it is expressed by the following equation.

'l'ocΦ人-Φ, (sin (120' +β6)
-sjn(5Q'+βo)) --(3)ζHere, when set to (β0 +=180'), the torque T is (
The torque T varies between (-0,866ΦAllΦF) and 0 when set to (βo = 120°). In other words, when setting (βo = 120'), there is a timing when the torque becomes zero, and the pulsating torque becomes large, so the set control advance angle β0 is set to 18 as much as possible.
It is desirable to set it near 0''.

In this way, by monitoring the phase control angle α on the power supply side, the optimum set control advance angle β0 is set so as to suppress the effect that the induced voltage of the motor increases excessively with respect to the power supply voltage.
is determined, and in particular, it is possible to make maximum use of regenerative torque, and furthermore, it is possible to realize commutatorless motor operation with less pulsating torque.

As described above, the technology based on this technical idea does not require any circuitry for detecting induced voltage or field current, and is effective without impairing the drive function of the motor by simply adding a simple phase angle detection circuit. It is possible to realize a device that obtains the desired results, and even reduces the power supply voltage and has an electric structure.

As explained above, according to the present invention, it is possible to provide a control method that can realize a simple device that monitors the power supply side phase control angle and changes the set control advance angle by a small amount until it reaches a predetermined value. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main structure of a conventional non-commutator motor control device, and FIG. 2 is a four-dimensional diagram shown to facilitate understanding of the technical idea of the present invention. ...Cycloconverter section, 3...
Synchronous motor, 6... Speed control circuit, 7...
...Phase control circuit, 8...Gate control circuit, 9.
...Power running regeneration discrimination circuit, 10.10'...
・Setting control advance angle control circuit, 12. Song phase angle detection circuit. Patent applicant Toyo Denki Seizo Co., Ltd. Representative Atsushi Doi

Claims (1)

[Claims] Sl'1 An armature winding of the same camphor motor (a device for energizing the armature winding of the synchronous motor by a power converter comprising a plurality of switching elements connected to each other) A method for controlling a commutator motor, characterized in that the regenerative torque amount of the synchronous motor is increased by changing a set control lead angle when a power supply side phase angle reaches a predetermined value. Setting control lead angle control method for sub motor.