KR0136116B1 - Motor speed control method - Google Patents

Abstract

The present invention relates to a motor speed control, and more particularly, to a motor speed control method for easily controlling the motor speed by comparing the speed detection value and the command value when compensating the speed by controlling the phase by controlling the single-phase motor. will be.

The object of the present invention is to detect the actual speed of the motor every half cycle of the commercial power frequency, to compare the detected actual speed and the command speed to detect the speed error, and to detect the detected speed error to determine the speed state Determining, calculating a proportional-integral compensation value according to the determined speed state, converting the calculated proportional-integral compensation value into an angle value, and outputting the converted angle value as a motor control signal to the motor. This is accomplished by executing a step of controlling the speed.

Description

Motor speed control method

1 is a configuration diagram of a conventional single-phase motor speed control device.

2 is a detailed block diagram of the proportional-integral control unit and the comparison unit of FIG.

3 is a configuration diagram of a single-phase motor speed control apparatus applied to the present invention.

4 is a motor speed detection flowchart of the present invention.

5 is a flow chart of the motor speed control signal of the present invention.

6 is a graph for explaining the determination of the motor speed of the present invention.

* Explanation of symbols for main parts of the drawings

100: motor 101: Hall sensor

102: interrupt generator 103: central processing unit

104: Triac

The present invention relates to a motor speed control, and more particularly, to a motor speed control method for easily controlling the motor speed by comparing the speed detection value and the command value when compensating the speed by controlling the phase by controlling the single-phase motor. will be.

Conventional single-phase motor speed control apparatus, as shown in the accompanying drawings, Figure 1, the Hall sensor 2 for detecting the rotational frequency of the motor (1) and converts it into a spherical pulse and the Hall sensor (2) Frequency / voltage converter 3 for converting the square pulse output from the corresponding voltage into a corresponding voltage, and frequency / voltage converter for converting the square pulse output from the Hall sensor 2 to the corresponding voltage (3), the proportional-integral control section 4 which compares the voltage obtained by the frequency / voltage converting section 3 with the reference voltage for speed setting, detects the error, and outputs an error compensation value; A phase detector 5 for detecting the phase of the voltage supplied to the motor 1, a triangle wave generator 6 for generating a triangle wave according to the phase detected by the phase detector 5, and the triangle wave generator 6 And the signals output from the proportional-integral control unit 4, respectively, Result and a comparison unit (7) for outputting a value, in accordance with an output of the comparison unit (7) consisted of a triac (8) for controlling the speed of said motor (1).

The operation of the conventional single-phase motor speed control device configured as described above will be described in detail with reference to FIG. 2.

First, since the AC power supplied to the motor has a zero point twice in one cycle, even when the motor driving device is turned on, it is automatically turned off near the OV.

For this reason, the triac is triggered every half cycle to maintain the driving of the motor.

This allows the triac to turn on at the zero cross point of the AC power source AC to rotate the motor.

1 is a device for controlling a motor using this principle. When the first triac 8a is turned on according to a speed command, current flows through the main coil M and ground current by the capacitor C is generated. By flowing through the sub-coil S, the alternating magnetic field in the single-phase motor 1 is changed into a rotating magnetic field so that the motor 1 rotates.

When the motor 1 rotates, the hall sensor 2 detects the rotation speed of the motor 1 and outputs it as a spherical pulse.

The frequency / voltage converter 3 receiving this rectangular pulse outputs a linear voltage with respect to the input frequency.

As shown in FIG. 2, the proportional-integral control unit 4 that receives a voltage corresponding to the rotation speed of the motor 1 may convert the voltage obtained from the frequency / voltage converter 3 into a first operation amplifier unit. The non-inverted amplification is performed at (4a), and the non-inverted amplified voltage value is non-inverted and amplified at the voltage value ratio corresponding to the speed command by the second operational amplifier 4b, and output as a speed error compensation value of the motor 1. Do it.

That is, the proportional-integral controller 4 compares the voltage value corresponding to the actual motor speed output from the frequency / voltage converter 3 with the commanded voltage value and outputs a voltage that compensates for the error.

In addition, the phase detection unit 5 detects the phase angle of the actual power supply to the motor 1, and the triangular wave generator 6 generates the triangular wave according to the detected phase angle.

Accordingly, the phase comparison unit 7 compares the phase of the triangular wave generated by the triangular wave generator 6 with the phase of the error compensation voltage output from the proportional-integral control unit 4, and the resultant value is triac. It becomes the drive signal of (8).

In this way, the drive signal of the triac 8 is calculated to control the motor 1 so that the motor 1 is controlled without a change in rpm according to the load variation of the motor 1 with respect to the change in the speed command value.

However, such a conventional motor speed control device requires a large number of operational amplifiers and passive elements to form a proportional-integration control circuit, and a circuit such as a frequency / voltage converter for feedback of the current speed of the motor is required. In addition to the complexity of the circuit configuration, the size of the product was disadvantageous.

Accordingly, an object of the present invention is to compare the speed detection value and the command value by software and to compensate for the error so that the speed of the motor can be easily controlled. In providing.

The method for achieving the object of the present invention comprises the steps of detecting the current motor speed every half cycle of the commercial power supply frequency, and subtracting the detected motor speed and the setpoint speed to recognize the motor speed state, and the recognition It is achieved by performing a step of determining a different error value in one motor speed state and a step of determining a firing angle with the determined error value, which will be described below in detail with reference to the accompanying drawings.

3 is a configuration diagram of a single-phase motor speed control device applied to the present invention. As shown in FIG. 3, the Hall sensor 101 detects the rotational frequency of the motor 100 and converts it into a spherical pulse and outputs it. The interrupt generator 102 detects the period of the signal and generates an interrupt signal every half cycle, receives the signals output from the interrupt generator 102 and the hall sensor 101, respectively, and calculates an error of the speed command value. A central processing unit 103 for controlling the speed of the motor by outputting an error compensation value, and a triac 104 for controlling the speed of the motor 100 according to a signal output from the central processing unit 103. do.

In the figure, reference numeral 105 denotes a capacitor for converting an alternating magnetic field into a rotating magnetic field.

Hereinafter, the present description will be described in detail with reference to FIGS. 4 and 5.

First, when the first triac 104a is turned on according to the speed command value output from the central processing unit 103, current flows in the main coil M, and the ground current by the condenser 105 is sub-coil ( By flowing in S), the alternating magnetic field in the single-phase motor 100 is converted into a rotating magnetic field so that the single-phase motor 100 rotates.

When the single phase motor 100 rotates, the hall sensor 101 detects the rotation speed of the motor 100 and outputs it as a spherical pulse.

In addition, from the moment the power is supplied to the motor 100, the interrupt generator 102 detects a cycle (16.6 msec) of the commercial power frequency (AC) 60HZ, and a half cycle (8.3 msec) of the cycle (16.6 msec). An interrupt is generated every time.

The central processing unit 103 receiving the generated interrupt detects the falling edge of the spherical pulse output from the hall sensor 101 as shown in FIG. 4 from the time when the interrupt is generated.

Then, the time from the first falling edge of the spherical pulse to the next falling edge is calculated, and the actual speed of the motor 100 is calculated using the calculated time.

By repeating this process, the current motor actual speed Wrm is detected.

And using the detected actual speed (Wrm) of the motor 100 to detect the error with the commanded speed value, which will be described in detail with reference to FIG.

That is, the subtraction Wrm * Wrm is subtracted from the commanded speed Wrm * of the detected speed 100 of the motor 100 (S1).

The resultant value thus obtained is determined as the speed error value We, and the speed error value We is compared with the speed command value α to determine whether the speed is under or overspeed (S3).

If the determination result is less than the speed, the proportional gain constant Kp is multiplied by the speed error We obtained above to calculate the control value Wp for proportional control (P control). The value is determined as the control value Wp of proportional control (S4).

Next, the first integral system is used to calculate the control value Wi for integral control (I control).

The result of multiplying (Wi ') r with integral gain constant (Ki), loop time (T), and speed error (We) and sum (Wi + Ki * We) Is determined as the control value Wi of the integral control (S5).

In the above, the first integration control value Wi is 0, and after that, it is a cumulative value.

The proportional (Wp) and integral (Wi) control values obtained as described above are summed (Wp + Wi) and

An example-integral compensation value W _Pi is calculated (S6).

Thereafter, the commanded speed value Wrm * is diffused into the angle value α (S7).

That is, the single motor 100 is turned on at zero as shown in FIG.

Since it stops at π after rotating 18800rpm, π / 188 * Wrm * is used to convert the command speed value (Wrm *) into an angle value (α).

The PI compensated speed value W _Pi is converted to the angle value Convert to W) (S8).

In other words, Converted to an angle value ( W) is converted into, and then the angle value (converted from the obtained angle value α to calculate the final firing angle when the speed falls short) W) is subtracted to determine the result as the final firing angle α (S9) to drive the triac 104 to compensate for underspeed.

On the other hand, if the determination result in the step S3 is overspeed, multiplying the proportional gain constant Kp by the speed error We obtained above to calculate the control value Wp for proportional control (P control). (Kp * We) The resultant value is determined as the control value Wp of proportional control (S10).

Next, in order to calculate the control value Wi for integral control (I control), the first integral control value Wi 'is multiplied by the integral gain constant Ki, the loop time T, and the speed error We. The resulting value obtained by adding up the value Ki * T * We and Wi + Ki * We is determined as the control value Wi of the integral control (S15).

In the above, the first integration control value Wi is 0, and after that, it is a cumulative value.

The proportional-integral compensation value W _Pi is calculated by summing up the proportional (Wp) and integral (Wi) control values obtained as described above (Wp + Wi) (S12).

Thereafter, the commanded speed value Wrm * is diffused into the angle value α (S13).

That is, since the single-phase motor 100 is turned on at zero and stopped at π after rotating 1800 rpm as shown in FIG. 6, the command speed value (Wrm *) is obtained by using π / 1800 * Wrm * using this. Is converted into an angle value α.

And the PI compensated speed value W _Pi as the angle value changed as described above ( Convert to W) (S14).

In other words, Angle value changed by W) is converted into, and then the angle value converted from the obtained angle value α to calculate the final firing angle at speed and speed ( W is added (α + ΔW) and the resulting value is determined as the final firing angle α (S15) to drive the triac 104 to compensate for overspeed.

If the error value calculated in the step S3 is smaller than 0 or larger than π, that is, when α to α'0, the motor is turned on at α = 0, and α = π when απ. Error can be compensated for any errors by stopping the motor.

As described in detail above, the present description can easily control the speed of the motor by software using the half period of the commercial power frequency and the output of the hall sensor, such as a controller and a voltage-frequency converter for controlling the existing motor speed. The hardware is unnecessary, so the circuit configuration is simple, and the speed control of the motor is accurate and easy.

In addition, the economics can be improved by eliminating the controller and the voltage-frequency converter.

Claims (8)

Receiving an interrupt corresponding to the half cycle of the commercial power frequency generated by the interrupt generating means, detecting a falling edge of the spherical pulse corresponding to the motor rotation obtained from the hall sensor when the interrupt is input; Detecting the actual speed of the motor by converting the time value into a speed value, including calculating the time from the detected falling edge to the next falling edge; and comparing the detected actual speed with the commanded speed Detecting an error, searching for a detected speed error, determining a speed state, calculating a proportional-integral compensation value according to the determined speed state, and converting the calculated proportional-integral compensation value into an angle value And controlling the motor speed by outputting the converted angle value as a motor control signal. The method of claim 1, The proportional-integral compensation value calculating step may include a first step of calculating a proportional-integral compensation value for the case where the determined motor speed is less than the second one, and a second-input for calculating the proportional-integral compensation value for the case where the determined motor speed is overspeed. Motor speed control method characterized in that consisting of steps. 4. The method of claim 3, wherein the first stage calculates the proportional compensation value Wp by multiplying the proportional gain constant Kp and the detected speed error We, and the initial integral value Wi and the integral gain constant. Calculating an integral compensation value (Wi) by adding (Wi + Ki, We) by multiplying (Ki), loop time (T), and speed error (We) by multiplying (KiT.We), And calculating the proportional-integral compensation value (Wp.i) by adding the calculated proportional compensation value (Wp) and the integral compensation value (Wi) (Wp + Wi). The method of claim 3, The second step is to calculate the proportional compensation value (Wp) by multiplying the proportional gain constant (Kp) and the detected speed error (We), the initial integral pack (Wi), the integral gain constant (Ki), and the loop time. Calculating the integral compensation value Wi by multiplying (TiWe) the speed error We and calculating the integral compensation value Wi; Calculating a proportional-integral compensation value (Wp-i) by adding (Wp) and the integral compensation value (Wi) (Wp + Wi). The method of claim 1, wherein the converting of the angle value comprises: a first step of converting the integral compensation value into an angle value when the actual speed of the motor is less than the proportional value when the actual speed of the motor is overspeed. A motor speed control method comprising the step of converting the integral compensation value into an angle value. The method of claim 6, The first step is to multiply the speed command value (Wrm *) by π / 1800 (Wrm * · π / 1800) to convert the speed command value to the first angle value (α), and proportional-integral compensation when the speed is not reached. Multiply the value (W _P-1 ) by π / 1800 and (W _Pi π / 1800) to obtain the second angle value ( W) and the second angle value (α) to the second angle value (α). Subtract W) (α- W) to determine the firing angle (α). The method of claim 6, wherein the second stage multiplies the speed command value (Wrm *) by π / 1800 and converts the speed command value to a first angle value (α), and the speeding day. In this case, the proportional-integral compensation value (W _Pi ) is multiplied by π / 1800 and (W _Pi · π / 1800) to obtain a second angle value ( W) and the second angle value (α) to the second angle value (α). And determining the firing angle [alpha] by summing up W). The method of claim 1, further comprising determining that the speed error is normal when the determined speed state is less than 0 or greater than π.