KR100314006B1 - Single phase srm drive circuit with power factor correction - Google Patents

Abstract

The present invention relates to a driving circuit of single-phase SM with active power factor correction, and since a separate circuit must be applied in the related art, an additional switch element and a driving circuit for driving the same are required, and thus are applied due to cost increase and complexity of the circuit. There is a problem that occurs when the burden. Therefore, the present invention is the upper reverse diode connected in series between the positive terminal and the negative terminal And high frequency switches and power factor correction sub-switch And the upper reverse diode And high frequency switches and power factor correction sub-switch Switch connected in parallel with And lower reverse diode And the upper reverse diode And high frequency switches and power factor correction sub-switch Connection point and the upper switch And motor windings connected between the connection points of the lower reverse diodes D _L And the upper switch And lower reverse diode Capacitor in parallel with And the upper reverse diode And high frequency switches and power factor correction sub-switch Reverse diode with cathode connected to junction Comprising the reactor (L) is connected in series with the anode, by using only the existing single-phase SM drive switch element to compensate for the active power factor at a low price, to improve the efficiency performance.

Description

SINGLE PHASE SRM DRIVE CIRCUIT WITH POWER FACTOR CORRECTION}

The present invention relates to a single-phase SM drive circuit capable of active power factor correction, which enables simple implementation of a circuit configuration to improve performance at a low cost. The present invention relates to a driving circuit of single-phase SLM capable of compensating active power factor at low cost.

FIG. 2 is a driving circuit diagram of a conventional three-phase SRM. As shown in FIG. 2, a DC link capacitor C for supplying a DC voltage obtained by smoothing an input power supply to an SM motor, and the number of N phases in parallel N motor windings La, Lb, and Lc connected to each other, and phase and lower switch elements Q1a, Q1b, and Q1c connected in series up and down to the motor windings La, Lb, and Lc. Freewheel diodes (FRD2, FRD4, FRD6) connected between the emitters of Q2c) and freewheel diodes (FRD3, FRD5) connected between the collectors of the upper and lower switch elements (Q1a, Q1b, Q1c) (Q2a, Q2b, Q2c). , FRD7).

4 is a driving circuit diagram of a conventional single-phase SLM, and as illustrated therein, a reactor L for removing noise from an input DC voltage Vs and a DC voltage passed through the reactor L are smoothed. Between the DC link capacitor C and the switch element Q1 and Q2 connected up and down in series with the motor winding, and the emitter of the upper switch element Q1 and the emitter of the lower switch element Q2. And a freewheel diode D1 connected between the connected freewheel diode D2 and the collector of the upper switch element Q1 and the collector of the lower switch element Q2.

And, Figure 5 is a drive circuit diagram of a conventional single-phase SRM capable of active power factor correction, as shown in the rectifier 10 for rectifying the commercial power input and output the rectified DC voltage, and the rectifier 10 Reactor (L) and shunt switch when DC voltage is output from And diode Active filter 20 to improve the power factor by using and to keep the output voltage constant, and the motor winding by switching the switch on / off by a switching signal when supplying voltage from the active filter 20 The motor drive unit 30 to control the current flowing through the RM to rotate, the current detector 40 for detecting the current flowing in the SM, and the current and voltage flowing through the SM to the active filter 20 Shunt switch of the active filter 20 such that the two values are the same as compared with the input current and the input voltage supplied to the reactor L. It consists of an average current controller 50 for controlling the operation of.

Looking at the prior art configured in this way in detail as follows.

In order to rotate the three-phase SRM (SRM) having the same structure as in FIG. 1, a DC voltage made by smoothing a power source to which the DC link capacitor C of FIG. 2 is input is supplied.

Then, the SRM rotates, and accordingly, by installing a disk having a photo interrupter and a slot associated with each phase inside the motor, the position of the rotor is detected by the photo sensor, and the detected rotor position Output the signal accordingly.

For example, a signal for causing the phase A to be induced is supplied to the bases of the upper and lower switch elements Q1a and Q2a connected in series to the motor winding La of the phase A, respectively.

Therefore, the upper and lower switch elements Q1a and Q2a of A phase are simultaneously turned on.

As the upper and lower switch elements Q1a and Q2a of A are turned on, current flows to the motor winding La, thereby allowing electricity to be induced to the motor windings La of A.

Subsequently, the upper and lower switch elements Q1a and Q2a of the A phase are turned off and the signals of the upper and lower switch elements Q1b and Q2b connected in series to the motor winding Lb of the B phase are connected to turn off the B phase. Each is supplied to the base.

At this time, the magnetic flux induced in the motor winding La of the phase A is removed by the freewheel diode frd3, the DC link capacitor C, the freewheel diode FRD2, and the motor winding La, and the motor rotates smoothly.

Likewise, in the case of phases B and C, the upper and lower switch elements Q1b and Q2b and Q1c and Q2c of phases B and C are sequentially turned on, so that the motor rotates clockwise.

In order to rotate in reverse, a current flows in the order of motor windings La, Lc, and Lb of A, C, and B phases.

Therefore, the three-phase RM rotates counterclockwise.

However, as shown in Fig. 4, in single-phase SM, only one single-phase series connection exists, and even in the case of having multiple poles, in parallel or in series, the current flows only once in the same direction. Will rotate.

In the case of three phases as shown in Figure 1, the rotation direction can be controlled by the energization order between the three phases, whereas in the case of single phase as shown in Figure 4, the rotation direction and model becomes unstable depending on the position of the protrusion of the rotor when starting the motor. In order to solve this problem, a permanent magnet is installed as in FIG. 3 to fix the position of the rotor to a position having good starting characteristics before starting the motor.

This solves the initial start up anxiety.

Referring to Fig. 5 for the operation for performing the power factor correction function in the single-phase SLM operating as described above, the commercial power supply to the rectifier 10 using a bridge diode to supply a DC voltage obtained by rectifying.

Shunt switch of the active filter 20 when a DC voltage is supplied from the rectifier 10 By appropriately controlling the current flowing through the reactor (L) to adjust the power factor to almost one.

When the power factor is adjusted, the motor winding is supplied to the motor driving unit 30 by supplying the voltage Vo charged in the filter capacitor C through the diode Dp. To flow.

At this time, the switching signal of the upper switch in the microcomputer not shown And sub-switch It is supplied at the same time by the

The upper switch And sub-switch Current switches to upper switch Motor winding And sub-switch It flows through the path of and rotates.

Therefore, single-phase SRM (SRM) has a characteristic that the power factor is improved.

And, the shunt switch of the active filter 20 The control of the control unit 50 inputs an input voltage across the resistor R1, an input current detected through the current detector 40, and an output voltage of the motor driver 30 across the resistor R2. Take control.

In recent years, regulations have been carried out around developed countries such as Europe to suppress harmonics.In particular, when inverters are used to control the variable speed of motors used for large power, such as vacuum cleaners, internal rectification and smoothing Wealth is a problem because of wealth. In order to solve this problem, it is necessary to apply a circuit that essentially compensates for active power factor as in the prior art, but additional switching elements and driving circuits for driving the same require a burden due to cost increase and complexity of the circuit. There is a problem.

Accordingly, an object of the present invention for solving the conventional problems as described above is to provide a drive circuit of a single-phase SLM capable of active power factor correction to improve performance at a low price.

It is another object of the present invention to provide a single-phase SM drive circuit capable of active power factor compensation, which enables the implementation of active power factor compensation at a low price using only a single phase SRM driving switch element without using a separate switch. Is in.

1 is a conventional three-phase SRM (SRM) structure diagram.

2 is a driving circuit diagram of a conventional three-phase SRM (SRM).

3 is a structural diagram of a conventional single-phase SRM (SRM).

4 is a driving circuit diagram of a conventional single-phase SM.

5 is a driving circuit diagram of a conventional single-phase SM capable of active power factor correction.

6 is another embodiment of the circuit diagram of FIG.

7 is a driving circuit diagram of a single-phase SML capable of active power factor correction of the present invention.

8 is a signal waveform diagram of each part shown in FIG.

*** Explanation of symbols for main parts of drawing ***

10: rectifier 20: active filter

30: motor drive unit 40: current detector

Top Reverse Diode Sub reverse diode

: Motor winding : Upper switch

: High frequency switch and power factor correction sub switch

The present invention for achieving the above object is in parallel with the upper reverse diode and the high frequency switch and power factor correction lower switch connected in series between the positive power terminal and the negative power terminal, and in parallel with the upper reverse diode and high frequency switch and power factor correction lower switch. An upper switch and a lower reverse diode connected to each other, a motor winding connected between a connection point of the upper reverse diode and a high frequency switch and a power factor correction lower switch, and a connection point of the upper switch and the lower reverse diode, and the upper switch and the lower reverse diode And a capacitor connected in parallel with the capacitor, a discharge resistor connected in parallel with the capacitor, and a reactor connected in series with an anode of a reverse diode having a cathode connected to a connection point of the upper reverse diode and the high frequency switch and the power factor correction lower switch. It features.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 is a circuit diagram of FIG. 5, which is a driving circuit of a conventional single-phase SM capable of active power factor correction, and is another exemplary embodiment in which the technical configuration of the motor driving unit 30 is changed according to the technical configuration of the present invention.

7 is a driving circuit diagram of a single-phase SM of the present invention capable of active power factor correction, as shown in the upper reverse diode connected in series between a positive power supply terminal and a negative power supply terminal. And high frequency switches and power factor correction subswitches And the upper reverse diode And high frequency switches and power factor correction subswitches Switch connected in parallel with And lower reverse diode And the upper reverse diode And high frequency switches and power factor correction subswitches Connection point and the upper switch And lower reverse diode Motor windings connected between junctions of And the upper switch And lower reverse diode Capacitor in Parallel with And a discharge resistor R connected in parallel to the capacitor Cs and the upper reverse diode. And high frequency switches and power factor correction subswitches Reverse diode with cathode connected to junction It consists of a reactor (L) connected in series with the anode of.

Referring to the operation and effect of the present invention configured as described in detail as follows.

The upper switch of the motor driving unit 30 in the driving circuit of SLM which combines the active power factor compensation of FIG. 5 described above. And lower reverse diode And upper reverse diode And sub-switch 6 and the mounting position of the reverse direction diode Dp, which is the output side of the active filter 20, is connected to one connection point of the motor winding LM, and the discharge resistance of the capacitor C It is configured by connecting R) in parallel.

Then, the voltage boosted through the reactor L and output through the diode Dp is the upper reverse diode in FIG. 5. 6 is applied to the cathode of the upper reverse diode There is a slight difference applied to the anode of.

However, in FIG. 6, the current supplied through the reactor L is a diode. Through the upper reverse diode Is charged to the capacitor (C) through the operation does not cause a large difference.

Where the shunt switch And sub-switch Is connected in parallel, the shunt switch Sub switch function Integrating the function of the unit does not cause any problem in operation.

Thus the shunt switch And sub-switch High frequency switch and power factor correction sub switch 7 is a signal waveform diagram according to the driving of the circuit of FIG. 7. (a) shows the inductance profile of the rotor with respect to the stator winding according to the mechanical angle of the rotor of SM. (b) shows the drive pulse for the upper switch Su, (c) shows the drive pulse for the high frequency switch and the low power switch Sp.L for power factor correction, and (d) shows the motor winding LM. The flowing current waveform is shown.

High Frequency Switch and Power Factor Correction Lower Switch When the power is turned on, the current flowing to the reactor L increases, and when the current exceeds a predetermined value, the high frequency switch and the power factor correction lower switch Off.

This operation is repeated to perform the active power factor correction function.

The high frequency switch and the power factor correction lower switch for active power factor correction as described above. When the on / off operation is repeated by the driving pulse as shown in FIG. 8 (c), the voltage boosted through the reactor L is the high frequency switch and the power factor correction lower switch Sp.L. Upper reverse diode on off Through the charge to the capacitor (C).

Therefore, the motor winding, which is the sovereignty of SLM. Upper switch to rotate by flowing current Is turned on by providing a driving pulse as shown in FIG. As long as the high frequency switch and the power factor correction lower switch (Sp.L) are turned on as above while , The current loop through the motor winding (LM) and the high frequency switch and power factor correction lower switch (Sp.L) is formed, In FIG. 8 (d), a current flows, and thus the motor winding As the current flows through the motor, rotation torque is generated in the SM motor to rotate.

Diode Motor winding This is to prevent the current flowing through the reactor L from flowing.

Thus, the motor winding The current flowing in the pulse width modulation (PWM) waveform as shown in (d) of FIG. 8 according to the on / off period of the high frequency switch and the power factor correction lower switch Sp.L while the upper switch Su is turned on. In this pulse width modulation waveform, since the correlation between the ON DUTY of the reactor current and the magnitude of the pulse width modulation according to the load variation is matched, a corrective operation according to the load variation occurs naturally.

As a result, the present invention shown in FIG. 7 makes it possible to perform active power factor compensation at a low price using only a single-phase SRM driving switch element without using a separate switching element. The stator and rotor ratios are 4 to 2 two-phase RMs, the stator and rotor ratios are 6 to 4 three-phase RSMs, and the stator and rotor ratios are 8 to 6 four-phase RMs.

Therefore, the present invention has the effect of compensating for the active power factor at a low price and improving the performance of efficiency by using only the conventional single-phase SM driving switch device without using a separate switch device.

Claims (1)

Upper reverse diode connected in series between positive and negative terminals And high frequency switches and power factor correction subswitches And the upper reverse diode And high frequency switches and power factor correction subswitches Switch connected in parallel with And lower reverse diode And the upper reverse diode And high frequency switches and power factor correction subswitches Connection point and the upper switch And lower reverse diode Motor windings connected between junctions of And the upper switch And lower reverse diode Capacitor in Parallel with And a discharge resistor R connected in parallel to the capacitor Cs, and the upper reverse diode. And high frequency switches and power factor correction subswitches Reverse diode with cathode connected to junction A drive circuit for single-phase SM with active power factor correction, characterized in that consisting of a reactor (L) connected in series with the anode of.