KR100320206B1 - The method of operation of reluctance motor - Google Patents

Abstract

The present invention relates to a method of driving a synchronous reluctance motor. In the related art, an interrupt caused by a position signal is electrically generated every 90 degrees by using two Hall sensors. When the interval of the interrupt is wide, There was a problem that the accuracy of the position was inferior and the determination of the rotation direction was impossible at the time of initial startup. Accordingly, the present invention includes a first step of processing a flag according to whether or not an interrupt signal for correcting a position signal is generated to calculate a correction angle? A second step of adding the correction angle [Delta] [theta] of the first step to the previous angle [theta] (t-1) and reading the sine of the addition angle [theta] (t) in a sine table; Performs the third step of outputting three-phase sinusoids by determining the corresponding area according to the occurrence of overflow, and improving the accuracy of the position signal by using one hall sensor and the ring magnet for position detection. A sinusoidal wave can be generated, and since a single hall sensor is used, cost can be reduced.

Description

Driving method of synchronous reluctance motor {THE METHOD OF OPERATION OF RELUCTANCE MOTOR}

The present invention relates to a method of driving a synchronous reluctance motor, and more particularly, to a method of driving a synchronous reluctance motor capable of generating a stable three-phase sine wave by using one hall sensor and a position detecting ring magnet.

Fig. 1 shows a basic flux-barrier synchronous reluctance motor in which torque is generated using the inductance difference between the Q-axis and the D-axis represented by the flux-barrier.

2 is a general diagram of a synchronous reluctance motor driving circuit of the most common three-phase sine wave driving method, wherein the motor is switched by an encoder for detecting a rotor position and a predetermined control signal to generate a three-phase sine wave when the motor is driven. An inverter unit for driving; And a microcomputer for controlling the switching of the inverter unit by the position detection signal of the encoder.

In the case of using the 2-phase energization method, since only the electrical separation is required every 60 degrees, a low-cost Hall sensor and a ring magnet are usually used instead of the encoder. In recent years, the performance of the microcomputer has improved in price. This allows three-phase sinusoidal drive using a Hall sensor instead of an encoder.

For example, Toshiba's TMP88CK49 uses the motor-specific function and capture function called PMD to receive position signals from two sensors and to estimate the position of each moment using the speed of each moment from the internal timer and capture function. One example of the pulse width modulation in this manner is the DEAD-BAND pulse width modulation method.

That is, after dividing the position detection signal of the Hall sensor into a 90-degree intervals as shown in Figure 3, the other parts to estimate the position from the inside by measuring the speed of the motor.

The output of each position uses a sine table, and the sine value corresponding to 0 to 120 degrees is stored in the sine table, and when driven, overflow or underflow occurs every 90 degrees and 90 degrees. The position is corrected through each interrupt.

That is, when two Hall sensors are used as described above, an interrupt caused by the position signal is electrically generated every 90 degrees. In this case, it is difficult to determine the rotation direction at the initial startup.

That is, as described above, the conventional device generates two interrupts by position signals electrically every 90 degrees by using two Hall sensors. When the interval of the interrupts is wide, the accuracy of the position is reduced. In addition, there was a problem in that it is impossible to determine the rotation direction during the initial startup.

Therefore, the present invention devised in view of the above-mentioned problems is a synchronous to generate a stable three-phase sine wave with one hall sensor and a position detection ring magnet by using a torque characteristic that can be driven even if only 180 degrees electrically. The purpose is to provide a method of driving a reluctance motor.

1 is a schematic diagram showing a synchronous reluctance motor in the form of a basic flux-barrier;

2 is a schematic diagram of a driving circuit of a general synchronous reluctance motor;

FIG. 3 is a timing diagram showing a DEAD-BAND pulse width modulation method in FIG.

4 is an operational flowchart of a method of driving a synchronous reluctance motor of the present invention;

Figure 5 is a schematic diagram showing the state of the Hall sensor and the ring magnet in Figure 4;

FIG. 6 is a view showing a three-phase sine wave output using a hall sensor and a ring magnet in FIG. 4; FIG.

The present invention for achieving the above object is a first step of calculating a correction angle (Δθ) from the speed data by predetermined processing of the flag (Flag) according to the presence or absence of the interrupt signal for correcting the position signal Wow; A second step of adding the correction angle [Delta] [theta] of the first step to the previous angle [theta] (t-1) and reading the sine of the addition angle [theta] (t) in a sine table; A third step of outputting a three-phase sine wave is determined by determining a corresponding region according to whether overflow occurs.

Hereinafter, the operation and effect of the synchronous reluctance motor driving method according to the present invention will be described in detail with reference to the accompanying drawings.

The apparatus to which the present invention is applied is the same as that of FIG. 1, except that only one Hall sensor is used, and FIG. 4 is an operation flowchart of the synchronous reluctance motor driving method of the present invention. A first step of processing a flag according to whether or not an interrupt signal is generated to calculate a correction angle Δθ from speed data; A second step of adding the correction angle [Delta] [theta] of the first step to the previous angle [theta] (t-1) and reading the sine of the addition angle [theta] (t) in a sine table; A third step of outputting a three-phase sine wave is determined by determining a corresponding area according to whether overflow occurs.

The first step includes determining whether a flag set inside is '1' when an interrupt signal is generated; Setting a flag of '0' and a position angle of 30 degrees if the flag is '1'; If the flag flag is '1', the flag flag is set to '1' and the position angle is set to 90 degrees.

The third step may include determining a position value '0' when the overflow occurs, adding an area value by '1', and determining whether the area value is '3'; If the area value is '3' as a result of the determination of the step, setting the first area, and if the area value is not '3', setting the area to the second area or the third area, and the operation of the present invention will be described. do.

First, the torque generated in the case of the synchronous reluctance motor as shown in FIG. 1 is implemented by the following equation.

------ Equation (1)

here, Denotes d, q-axis inductance and mmf angle, respectively.

In Equation 1, since the period of the synchronous reluctance motor is electrically 180 degrees, it is possible to drive even if only 180 degrees electrically, in the present invention, the three-phase sine wave is driven by using the same.

Herein, in the case of the 4-pole synchronous reluctance motor, the electric angle and the mechanical angle are doubled, that is, when the mechanical rotation is 180 degrees, the electrical angle is 360 degrees.

In this case, the magnet may be magnetized into four poles in order to electrically distinguish 180 degrees. In this case, only 180 degrees may be electrically distinguished, thereby causing problems during startup.

Therefore, the present invention uses a ring magnet magnetized into an 8-pole as shown in Figure 5, the number of poles is due to the design of the magnet yoke, there is no additional cost of using an 8-pole ring magnet.

6 shows a Hall sensor signal and a driving method. As can be seen from the position signal, a signal is generated every 90 degrees but is not electrically separated by 180 degrees.

That is, the area A and the area C, and the area B and the area D cannot be distinguished. In the case of the synchronous reluctance motor, the division of the front and rear 180 degrees sections is not meaningful according to Equation (1).

However, in actual driving, a flag is set inside the microcomputer to electrically distinguish 180 degrees.

In other words, the position at the initial start is set to 180 degrees in the first half and the flag is electrically changed every 180 degrees to separate the front and rear half. Also, the over-over occurs every 120 degrees using a sine table that stores sine values up to 120 degrees. The position correction is performed by using an overflow signal and an interrupt signal generated every 90 degrees.

In other words, the present invention calculates a correction angle Δθ from velocity data by processing a flag according to the presence or absence of an interrupt signal for correcting a position signal, that is, an interrupt signal is generated. If the flag is set to '1', if the flag is set to '1', the flag is set to '0', the position angle θ is set to 30 degrees, and the flag is set. If is not '1', the flag Flag is set to '1' and the position angle θ is set to 90 degrees.

Then, the correction angle Δθ is added to the previous angle θ (t-1), and the sine of the addition angle θ (t) is read in the sine table.

Here, the sine table comprises a RAM that stores sine values of 0 to 120 degrees.

Then, the area is determined according to the occurrence of overflow, and a three-phase sine wave corresponding to the sine value is output. In other words, when overflow occurs, the position angle θ is set to '0'. After adding the area value by '1', it is determined whether the area value is '3' and if the area value is '3', it is set as the first area.If the area value is not '3', the second area or the third area is added. After setting to area, output 3-phase sine wave corresponding to the area setting value as shown in Table 1.

U V W First area sin (θ) 0 sin (2π / 3 -θ) Second area sin (2π / 3 -θ) sin (θ) 0 Third area 0 sin (2π / 3 -θ) sin (θ)

As described in detail above, the present invention can stably generate a three-phase sine wave by improving the accuracy of the position signal by using one hall sensor and a ring magnet for position detection, and further reduces the cost by using one hall sensor. It is effective.

Claims (10)

A first step of processing a flag according to whether or not an interrupt signal for correcting a position signal is generated to calculate a correction angle? A second step of adding the correction angle [Delta] [theta] of the first step to the previous angle [theta] (t-1) and reading the sine of the addition angle [theta] (t) in a sine table; A method of driving a synchronous reluctance motor, characterized in that the third step of outputting a three-phase sine wave is determined by determining a corresponding area according to whether overflow occurs. The method of driving a synchronous reluctance motor according to claim 1, wherein the three-phase sine wave is generated using one Hall sensor and a ring magnet. The method of driving a synchronous reluctance motor according to claim 2, wherein the ring magnet is magnetized into eight poles. The method of claim 1, wherein the sine table is a RAM in which sine values of 0 to 120 degrees are pre-stored. The method of driving a synchronous reluctance motor according to claim 1, wherein the overflow occurs at intervals of 120 degrees. The method of claim 1, wherein an interrupt signal is generated at intervals of 90 degrees. The method of claim 1, further comprising: determining whether a flag set inside is '1' when an interrupt signal is generated; Setting the flag Flag to '0' and the position angle [theta] to 30 degrees if the flag Flag is '1'; If the flag Flag is not '1' as a result of the determination of the above step, the flag Flag is set to '1' and the position angle θ is set to 90 degrees. Way. The method of claim 3, wherein the flag is electrically divided by 180 degrees. The method of claim 1, wherein in the third step, when an overflow occurs, the position angle θ is set to '0', and the area value is added by '1', and then it is determined whether the area value is '3'. Making a step; And setting the first region if the region value is '3', and setting the second region or the third region if the region value is not '3'. Driving method. The method of claim 3, wherein the first, second, and third regions are divided by 120 degree intervals.