KR20200000702A - Control device and method of SPSR motor with auxiliary winding - Google Patents

Abstract

Disclosed are a control device of a single-phase SR (SPSR) motor using auxiliary winding wires and a control method thereof. According to an embodiment of the present invention, the control device of a SPSR motor having a main winding wire and an auxiliary winding wire comprises: a rotor speed estimation unit estimating a speed of a rotor from rotor location information obtained from a location sensor; a duty cycle calculation unit calculating a duty ratio when the rotor is located at a location in which current of the main winding wire generates positive (+) torque by corresponding to the speed of the rotor; and a pulse generation unit generating a single pulse corresponding to the duty ratio and outputting the single pulse.

Description

Control device and method of SPSR motor with auxiliary winding

The present invention relates to a control apparatus and a control method of a single-phase SR motor (SPSR motor) using an auxiliary winding.

In the case of single phase RAL motors, an auxiliary winding is used for self-starting. The main winding of the single-phase RAL motor serves to generate constant driving torque, whereas the auxiliary winding generates torque only at start-up to assist the main winding, unlike the main winding.

In general, single-phase RAL motors are mainly used in low-cost fan or blower motors, so the current of the auxiliary winding is not controlled because the minimum control circuit is configured to reduce the cost. Therefore, the power semiconductor switching element is used to control the current flowing in the main winding, but does not use a separate switching element because it does not control the current of the auxiliary winding.

Since there is no switching element to control the auxiliary winding, the commutation of the current flowing in the auxiliary winding is not made smoothly, so that negative torque is generated, which reduces the average output torque of the motor, which leads to a decrease in efficiency. .

Korea Patent Registration No. 10-0260738 (registered on Apr. 11, 2000)-Control device of SR motor and its control method

The present invention does not use a switching element for controlling the current of the auxiliary winding, thereby minimizing the negative torque caused by the current of the auxiliary winding while maintaining cost savings, thereby improving the average torque and efficiency of the single-phase SL motor. It is to provide a control device and a control method of a single-phase RAL motor using.

The present invention increases the efficiency of the motor by reducing the value of the negative torque by applying a control algorithm that greatly reduces the section in which negative torque occurs even when current flows in the auxiliary winding compared to the conventional control technology. It is to provide a control device and a control method of a single-phase RAL motor using an auxiliary winding.

Other objects of the present invention will be readily understood through the following description.

According to an aspect of the present invention, there is provided a control apparatus for a single-phase RAL motor having a main winding and an auxiliary winding, the apparatus comprising: a rotor speed estimating unit estimating a rotor speed from rotor position information obtained from a position sensor; A duty cycle calculator configured to calculate a duty ratio when the rotor is in a section position where the current of the main winding generates positive torque corresponding to the speed of the rotor; And a pulse generator for generating and outputting a single pulse corresponding to the duty ratio.

In another embodiment of the present invention, there is provided a control apparatus of a single-phase RAL motor having a main winding and an auxiliary winding, the apparatus comprising: a rotor speed estimating unit estimating a speed of a rotor from rotor position information obtained from a position sensor; A proportional integral (PI) control unit configured to calculate a duty ratio by performing proportional integration control using the speed of the rotor; And a pulse generator for generating and outputting a single pulse corresponding to the duty ratio.

The single pulse may be a gating pulse for switching power semiconductors.

According to another aspect of the present invention, there is provided a control method of a single-phase RAL motor having a main winding and an auxiliary winding, the method comprising: estimating a speed of a rotor from rotor position information obtained from a position sensor; Calculating a duty ratio when the rotor is in a section position where the current of the main winding generates positive torque corresponding to the speed of the rotor; And generating and outputting a single pulse corresponding to the duty ratio.

In another embodiment, a control device of a single-phase RAL motor having a main winding and an auxiliary winding, comprising: estimating a speed of a rotor from rotor position information obtained from a position sensor; Calculating a duty ratio by performing proportional integration control using the speed of the rotor; And generating and outputting a single pulse corresponding to the duty ratio.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to an embodiment of the present invention, the average torque and efficiency of the single-phase RAL motor are minimized by minimizing the negative torque caused by the current of the auxiliary winding while maintaining cost savings by not using a switching element for controlling the current of the auxiliary winding. Has the effect of improving.

In addition, the effect of increasing the efficiency of the motor by reducing the value of the negative torque by applying a control algorithm that significantly reduces the section where the negative torque occurs even when current flows in the auxiliary winding compared to the conventional control technology. There is also.

1 is a driving circuit of a single-phase RAL motor using an auxiliary winding for self-starting,
2 is a view showing a control strategy of a conventional single-phase RAL motor,
3 is a diagram comparing a conventional PWM control technique and a single pulse technique,
4 is a graph showing voltage, current, and torque waveforms when the single pulse technique is applied;
5 is a block diagram of a single-phase RAL motor control apparatus using an auxiliary winding according to an embodiment of the present invention,
6 is a flow chart of a control method of a single phase SR motor;
Figure 7 is a block diagram of a single phase SL motor control apparatus using an auxiliary winding according to another embodiment of the present invention.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In addition, the components of the embodiments described with reference to the drawings are not limited to the corresponding embodiments, and may be implemented to be included in other embodiments within the scope of the technical spirit of the present invention. Even if the description is omitted, it is obvious that a plurality of embodiments may be reimplemented into one integrated embodiment.

In addition, in the description with reference to the accompanying drawings, the same components regardless of reference numerals will be given the same or related reference numerals and redundant description thereof will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, the terms “… unit”, “… module”, “… group” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. Can be.

1 is a driving circuit of a single phase RAL motor using an auxiliary winding for self-starting.

In FIG. 1, L _m represents the inductance of the primary winding and L _a represents the inductance of the auxiliary winding. Q1 is a power semiconductor switching element (MOSFET or IGBT) for controlling the current in the main winding.

A disadvantage of the driving circuit as shown in Figure 1 is that the current of the main winding can flow through the auxiliary winding when Q1 is turned off to control the current of the main winding. In addition, current may flow in the auxiliary winding due to the charge of C2 and the energy transferred from the inductor of the primary winding to the inductor of the auxiliary winding. The current in the main winding is regulated by switching the phase with pulse width modulation (PWM), which means that simultaneous currents occur in the main and secondary windings.

The purpose of the auxiliary winding is to assist the starting torque of the main winding by allowing current to flow only when starting the motor. Therefore, no current should flow after the motor is started.

2 is a diagram illustrating a control strategy of a conventional single phase SR motor.

In FIG. 2, i _m and i _a are the currents of the main winding and the auxiliary winding, respectively, T _em and T _ea are the torques generated by the main winding and the auxiliary winding, respectively, and T _e is the summed torque.

The control strategy of the existing single phase SR motor is PWM current control.

At speeds below the rated speed, the duty cycle of the controllable switch is less than one. This produces a current in the secondary winding that mirrors the current in the primary winding each time switch Q1 is turned off.

As shown in FIG. 2, a positive torque is generated by the main winding current i _m , but a negative torque is generated by the auxiliary winding current i _a . As a result, the total generated torque (sum of the main winding torque and the auxiliary winding torque) is reduced.

3 is a diagram comparing a conventional PWM control technique with a single pulse technique.

In the PWM technique, several pulses having the switching period Tc exist during the excitation period T, and the average value of the voltage V _{m (i)} applied to the main winding is expressed by Equation 1.

[Equation 1]

d represents the percentage of time that the V _dc voltage is generated by switching on for a given period (T or T _c ).

In the case of the single pulse technique, there is only one pulse during the excitation period, T (the interval where L _m increases), and the average value of the voltage V _{m (ii)} at this time is expressed by Equation 2.

[Equation 2]

Comparing Equations 1 and 2 results in the same value.

The voltage, current, and torque waveforms when applying the single pulse technique as shown at the bottom of FIG. 3 are shown in FIG. 4.

When the PWM technique is applied, current flows in the auxiliary winding during the excitation section (T), but in the case of a single pulse, as shown in FIG. 4, no current flows in the auxiliary winding during the excitation section, and the switch turns after the switch-on time (dT). Only during the on period will current flow through the auxiliary winding. Therefore, unlike the PWM technique, the negative torque generation by the auxiliary winding current is reduced, thereby reducing the average torque reduction.

Comparing FIG. 4 with the conventional control shown in FIG. 2, the advantages become apparent. The disadvantage is that the torque consists of two pulses, which have a short duration compared to conventional control.

The torque generation section will be described as follows.

The main winding torque generation time is dT for the entire excitation section T. This means that in both cases, higher torques must be produced for a shorter period of time to produce the same average torque.

[Equation 3]

Here, T _en is the torque generated by the proposed single pulse technique, and T _ec is the torque generated based on the conventional scheme.

For the conceptual understanding, assuming that the waveform of the torque is rectangular, the torque generated by the single pulse technique according to the embodiment of the present invention is represented by Equation 4.

[Equation 4]

And the torque by the conventional method (PWM method) is shown in Equation 5.

[Equation 5]

5 is a block diagram of a single-phase RAL motor control apparatus using an auxiliary winding according to an embodiment of the present invention, Figure 6 is a flow chart of a control method of a single-phase RAL motor.

The single phase SL motor control apparatus 100 according to the present exemplary embodiment performs a motor control by performing a single pulse-based current control method.

The single phase SL motor controller 100 includes a speed estimator 110, a duty cycle calculator 120, and a pulse generator 130.

The speed estimator 110 may estimate the rotor speed ω _m from the rotor position information θ (step S200) obtained from a position sensor such as an encoder or a hall sensor (step S210).

In addition, the duty cycle calculation unit 120 corresponds to the duty cycle (duty ratio) when the rotor is located at a section (ie, an excitation section) where the current of the main winding may generate a positive torque according to the speed of the rotor. d) is calculated (step S220).

The pulse generator 130 generates and outputs a single pulse (gating pulse) V _g for switching the power semiconductor using the duty cycle calculated by the duty cycle calculator 120 (step S230).

7 is a block diagram of a single-phase SL motor control apparatus using an auxiliary winding according to another embodiment of the present invention.

Since the single-phase SL motor control apparatus 300 shown in FIG. 7 calculates the duty ratio through speed control without calculating the duty ratio, more robust control performance can be obtained.

The single phase SL motor controller 300 according to the present exemplary embodiment includes a speed estimator 310, a PI controller 320, and a pulse generator 330. Each of the speed estimator 310 and the pulse generator 330 performs the same functions as the speed estimator 110 and the pulse generator 130 shown in FIG. 5.

The PI controller 320 may calculate the duty ratio d by performing proportional integration control using the rotor speed.

The single-phase SL motor control apparatus and method according to the embodiments of the present invention described above are suitable for low-cost motor driving systems such as fans and blowers in low-cost and low-performance applications that do not require high performance control or high efficiency.

Although the above has been described with reference to embodiments of the present invention, those skilled in the art may variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. And can be changed.

100: single-phase SR motor controller 110: speed estimation unit
120: duty cycle calculator 130: pulse generator
300: single phase SR motor control device 310: speed estimation unit
320: PI controller 330: pulse generator

Claims (6)

As a control device of a single phase RAL motor having a main winding and an auxiliary winding,
A rotor speed estimator for estimating the speed of the rotor from the rotor position information obtained from the position sensor;
A duty cycle calculator configured to calculate a duty ratio when the rotor is in a section position where the current of the main winding generates positive torque corresponding to the speed of the rotor; And
And a pulse generator for generating and outputting a single pulse corresponding to the duty ratio.
As a control device of a single phase RAL motor having a main winding and an auxiliary winding,
A rotor speed estimator for estimating the speed of the rotor from the rotor position information obtained from the position sensor;
A proportional integral (PI) control unit configured to calculate a duty ratio by performing proportional integration control using the speed of the rotor; And
And a pulse generator for generating and outputting a single pulse corresponding to the duty ratio.
The method according to claim 1 or 2,
Wherein said single pulse is a gating pulse for switching power semiconductors.
A control method of a single phase RAL motor having a main winding and an auxiliary winding,
Estimating the speed of the rotor from the rotor position information obtained from the position sensor;
Calculating, according to the speed of the rotor, the duty ratio when the rotor is in the section position where the current of the main winding generates positive torque; And
And generating and outputting a single pulse corresponding to the duty ratio.
As a control device of a single phase RAL motor having a main winding and an auxiliary winding,
Estimating the speed of the rotor from the rotor position information obtained from the position sensor;
Calculating a duty ratio by performing proportional integration control using the speed of the rotor; And
And generating and outputting a single pulse corresponding to the duty ratio.
The method according to claim 4 or 5,
Wherein said single pulse is a gating pulse for switching power semiconductors.

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