KR20140064433A

KR20140064433A - Eletrolysis capacitorless inverter driving apparatus

Info

Publication number: KR20140064433A
Application number: KR1020120131763A
Authority: KR
Inventors: 조원진; 이효진
Original assignee: 삼성전기주식회사
Priority date: 2012-11-20
Filing date: 2012-11-20
Publication date: 2014-05-28

Abstract

The present invention relates to an electrolytic capacitor-less inverter driving apparatus, and more particularly, to an electrolytic capacitor-less inverter driving apparatus comprising: a film capacitor for receiving and smoothing a power source; An inverter having a plurality of switching elements and converting a DC voltage output from the film capacitor into a motor driving voltage according to a control signal and outputting the converted DC voltage to a motor; And a control unit for generating a pulse width control signal by using a carrier signal and a reference signal reflecting offsets proportional to voltage ripple across the film capacitor and outputting the pulse width control signal to the inverter.

Description

[0001] The present invention relates to an electrolytic capacitorless inverter driving apparatus,

The present invention relates to an electrolytic capacitorless inverter drive system.

In general, inverters are widely used throughout the industry including motor applications and various electric devices.

The inverter generates an AC voltage by switching a DC voltage to a switching element and outputs the generated AC voltage to a load so as to supply the AC voltage of a desired voltage and frequency to the load to precisely control the driving of the load can do. As the switching device, an IGBT (Insulated Gate Bipolar Transistor) is commonly used.

Such an inverter includes a gate driver and a switching unit for generating an AC voltage by switching a DC voltage of the power supply terminal in accordance with a switching signal of the gate driver.

In the switching unit, switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) are connected in series between the power supply terminal and ground, and the gates of the switching elements IGBT1 to IGBT6 are connected to the gate driver The output terminals are connected through resistors.

A connection point between the series-connected switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) is connected to the load.

In the inverter configured as described above, in a state where a DC voltage is supplied to the power supply terminal, the gate driver selectively outputs a switching signal having a high potential of logic 1 and a low potential of logic 0, to a plurality of output terminals.

The switching signal output from the gate driver is applied to the gates of the plurality of switching elements IGBT1 to IGBT6 through the resistor of the switching unit.

Then, the plurality of switching elements IGBT1 to IGBT6 are selectively turned on and off according to the switching signal.

The DC voltage of the power supply terminal is converted into an AC voltage and supplied to the load in accordance with the turn-on and turn-off of the plurality of switching elements IGBT1 to IGBT6.

On the other hand, as the demand for inverter-type household appliances having excellent power efficiency in such inverters increases, expectations for the life span of household appliances are increasing.

In this situation, large capacity electrolytic capacitors, which are one of the main components of the inverter, have a limited life span and have relatively low durability due to environmental factors such as temperature and vibration. Therefore, the reliability and life span of the electrolytic capacitor It is becoming an important factor to decide.

KR2007-7028385

The present invention has been devised in order to solve the above-mentioned problems, and it is an object of the present invention to provide an electrolytic capacitorless inverter drive device in which an electrolytic capacitor is replaced with a film capacitor excellent in durability and lifetime, and the generation of voltage ripple is suppressed.

According to an aspect of the present invention, there is provided a plasma display apparatus comprising: a film capacitor for receiving and smoothing a power source; An inverter having a plurality of switching elements and converting a DC voltage output from the film capacitor into a motor driving voltage according to a control signal and outputting the converted DC voltage to a motor; And a controller for generating a pulse width control signal using the carrier signal and the reference signal, the offset of which is proportional to the voltage ripple across the film capacitor, and outputting the pulse width control signal to the inverter.

In addition, the present invention further includes a rectifying unit that receives the AC power and provides DC power to the film capacitor.

The switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) are connected in series between the power supply terminal and the ground, and the switching elements IGBT1 and IGBT2 The output terminal of the control section 140 is connected to the gate of the IGBT 6 and the connection point between the series-connected switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) is connected to the load.

In addition, the control unit of the present invention is characterized by generating an offset value proportional to voltage ripple across the film capacitor at the time of generating the offset value, and also to be proportional to the reference signal.

Also, the control unit of the present invention may include a reference signal generator for generating a reference signal that is a sine wave; An offset generator for measuring a voltage at both ends of the film capacitor and outputting an offset value proportional to a voltage at both ends measured and proportional to a reference signal; A carrier signal generator for generating a carrier signal which is a triangle wave in which an offset generated in the offset generator is reflected; A pulse signal generator for generating a pulse width control signal by using a reference signal outputted from the reference signal generator and a carrier signal which is a triangle wave outputted from the carrier signal generator; And a gate driver for applying a switching signal corresponding to a pulse width control signal output from the pulse signal generator to each gate of the plurality of switching elements.

The offset generator of the present invention may further include: a first amplifier that receives the reference signal from the reference signal generator and multiplies the reference signal by K1; A second amplifier for receiving a voltage ripple of both ends of the voltage measured by the film capacitor and multiplying it by K2; And a multiplier for multiplying the signal passed through the first amplifier and the signal passed through the second amplifier and outputting the multiplied signal.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to that, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may properly define the concept of the term in order to best explain its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

According to the present invention as described above, the durability and lifetime of the inverter can be extended by replacing the electrolytic capacitor with a film capacitor having excellent durability and long life.

Further, according to the present invention, the output current unbalance caused by the voltage ripple of the film capacitor is suppressed so that the torque of the motor can be uniformly applied.

Thus, the application of a balanced torque not only enhances the efficiency of the motor but also suppresses the vibration of the motor and improves the noise caused by vibration.

1 is a configuration diagram of an electrolytic capacitorless inverter drive apparatus according to an embodiment of the present invention.
2 is a detailed block diagram of the control unit of FIG.
FIG. 3A is a waveform chart showing a reference signal generated in the reference signal generator of FIG. 2, FIG. 3B is a graph showing a voltage across the film capacitor, and FIG. 3C is a graph showing a carrier signal output from the carrier signal generator of FIG. .
4 is a detailed block diagram of the offset generator of FIG.
5 is an output waveform diagram of an electrolytic capacitorless inverter driving apparatus according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. It is also to be understood that the terms "first,"" second, "" one side,"" other, "and the like are used to distinguish one element from another, no. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of related arts which may unnecessarily obscure the gist of the present invention will be omitted.

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

1 is a configuration diagram of an electrolytic capacitorless inverter drive apparatus according to an embodiment of the present invention.

1, the apparatus for driving an electrolytic capacitor-less inverter according to the present invention includes a rectifying unit 110 for rectifying an AC voltage supplied from an AC power supply 100 to output a DC voltage, An inverter 130 having a plurality of switching elements and converting a DC voltage output from the film capacitor according to a control signal into a motor driving voltage and outputting the same to a motor; And a controller 140 for generating a pulse width control signal by using a carrier signal and a reference signal, which are proportional to the voltage ripple of the film capacitor 120 and further reflecting an offset proportional to the reference signal, and outputting the pulse width control signal to the inverter .

In this configuration, the rectifying unit 110 has a plurality of diodes and converts the AC power to DC power and outputs the DC power.

The film capacitor 120 is connected between the rectifying unit 110 and the inverter 130 to smooth the output voltage of the rectifying unit 110 and store the output voltage.

Since the capacity of the film capacitor 120 is smaller than that of a conventional electrolytic capacitor, the voltage ripple increases and an unbalance of the three-phase output current occurs due to the increased voltage ripple.

In order to solve this problem, in the present invention, the controller 140 uses a carrier signal and a reference signal, which are proportional to the voltage ripple of the film capacitor 120, and additionally reflect an offset proportional to the reference signal, Width control signal so as to control the inverter 130, thereby controlling the balance of waveforms in which the output current balances of the conventional phase are unbalanced. This operation principle will be described in detail with reference to FIG. 2 and the following.

The inverter 130 includes a plurality of switching elements and applies a motor driving current according to a voltage command to the motor using a control signal generated from the controller 140, for example, a pulse width control signal.

In this inverter 130, two switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) are connected in series between two power supply terminals and a ground, and the gates of the switching elements IGBT1 to IGBT6 are connected, (140) are connected to each other.

The connection point between the series-connected switching elements IGBT1, IGBT2 (IGBT3, IGBT4) (IGBT5, IGBT6) is connected to a load-side motor.

The thus configured electrolytic capacitorless inverter drive apparatus is supplied with an alternating current power supply 100 and the rectifying unit 110 rectifies and outputs the direct current power so that the film capacitor 120 smoothly stores and stores the direct current power.

When the direct current voltage is supplied to the inverter 130, the control unit 140 outputs a switching signal having a logic high of 1 and a logical low of 0 to the plurality of output terminals.

The switching signal output from the controller 140 is applied to the gates of the plurality of switching elements IGBT1 to IGBT6, respectively.

The DC voltage of the power supply terminal is converted into an AC voltage in accordance with the turn-on and turn-off of the plurality of switching elements IGBT1 to IGBT6 and supplied to the motor serving as a load.

2 is a detailed block diagram of the control unit of FIG.

Referring to FIG. 2, the control unit of FIG. 1 includes a reference signal generator 141 and an offset value proportional to the voltage ripple of the both-end voltage measured by measuring the voltage across the film capacitor and further proportional to the reference signal A carrier signal generator 143 for generating a carrier signal which is a triangle wave in which the offset generated by the offset generator 142 is reflected, a reference signal generator 143 for generating a reference signal output from the reference signal generator 141, And a pulse signal generator 144 and a gate driver 145 that generate a pulse width control signal using a carrier signal that is a triangle wave output from the generator 143. [

The reference signal generator 141 generates a reference signal of a sine wave as shown in FIG. 3A and provides it to the pulse signal generator 144.

The offset generator 142 measures the voltage across the film capacitor and outputs an offset value proportional to the voltage ripple.

At this time, the offset generator 142 measures the voltage at both ends of the film capacitor, outputs a positive offset value when the voltage ripple of the voltage across the film capacitor is large based on the constant voltage, And outputs a negative offset value if it is smaller than the predetermined voltage.

If the offset generator 142 outputs an offset value proportional to the voltage ripple of the voltage across the film capacitor, as shown in FIG. 3B, in the section where the voltage ripple of the film capacitor is large (for example, the G section) An offset value is output, and a negative offset value is output in a section where the voltage ripple of the film capacitor is small (for example, section S).

In addition, when the portion of the reference signal having a large magnitude and the portion having a large voltage ripple of the film capacitor meet, the offset generator 142 increases the unbalance of the output current. Thus, the offset generator 142 reflects the magnitude of the reference signal, So that an offset value proportional to the size can be output.

This can be expressed by the following equation (1).

(1)

Voffset = (Vref * K1) * (Vdc * K2)

Here, Voffset represents an offset value, Vref represents a reference signal, Vdc represents a voltage ripple of the film capacitor, and K1 and K2 represent a proportional constant.

Meanwhile, the carrier signal generator 143 generates and outputs a carrier signal which is a triangle wave reflecting the offset generated by the offset generator 142.

At this time, when the offset generator 252 outputs a positive offset value in a section where the voltage ripple of the film capacitor is large, the carrier signal generator 143 adds a positive offset value to the triangular wave as shown in the upper part of FIG. 3C A carrier signal is output. On the contrary, if a negative offset value is output in a section where the voltage ripple of the film capacitor is small, a carrier signal obtained by subtracting a negative offset value from the triangular wave is output as shown in the lower part of FIG. 3C .

The pulse signal generator 144 is connected to the reference signal generator 141 and a carrier signal generator 143 for outputting a triangular wave reflecting the offset.

Such a pulse signal generator 144 is designed to receive and compare a carrier signal, which is a triangular wave reflecting an offset value, and a reference signal in order to output a pulse control signal for controlling a switching element of the inverter.

The pulse signal generator 144 compares the magnitude of the reference signal with the triangular wave signal with the reflected offset. If the reference signal is larger than the triangular wave signal, the pulse signal generator 144 outputs a signal having a high potential. Conversely, if the reference signal is smaller than the triangular wave signal, Lt; / RTI >

Next, the gate driver 145 outputs a switching signal having a high potential, which is a logic 1, and a logic 0, which are low, selectively to a plurality of output terminals in accordance with a pulse width control signal.

The operation of the control unit thus configured will be described below.

The reference signal generator 141 generates a reference signal of a sine wave and provides it to the pulse signal generator 144.

The offset generator 142 measures the voltage at both ends of the film capacitor and outputs an offset value proportional to the voltage ripple and further proportional to the reference signal. At this time, the offset generator 142 calculates the voltage at both ends of the film capacitor If the voltage ripple at both ends of the film capacitor is large based on a constant voltage, a positive offset value is output. If the voltage ripple at both ends of the film capacitor is smaller than a predetermined voltage, a negative offset value is output.

When the offset generator 142 outputs an offset value proportional to the voltage ripple at both ends of the film capacitor and proportional to the reference signal, a positive offset value is output in a section where the voltage ripple of the film capacitor is large. A negative offset value is output in a small voltage ripple region.

When the offset generator 142 outputs a positive offset value during a period where the voltage ripple of the film capacitor is large, the carrier signal generator 143 outputs a carrier signal added with a positive offset value to the triangular wave. On the other hand, In the section where the voltage ripple of the film capacitor is small, when the negative offset value is output, the carrier signal generator 143 outputs the carrier signal whose negative offset value is subtracted from the triangular wave.

If the reference signal is smaller than the triangular wave signal, the pulse signal generator 144 outputs a signal having a high potential if the reference signal is larger than the triangular wave signal. On the contrary, if the reference signal is smaller than the triangular wave signal, And outputs a signal having a potential.

At this time, when the carrier signal generator 143 outputs a carrier signal obtained by adding a positive offset value to the triangular wave, the pulse signal generator 144 outputs a pulse width control signal with a reduced pulse width.

On the other hand, when the carrier signal generator 143 outputs a carrier signal obtained by adding a negative offset value to the triangular wave, the pulse signal generator 144 outputs a pulse width control signal with an increased pulse width.

The pulse width control signal output from the pulse signal generator 144 is applied to the gates of the plurality of switching elements IGBT1 to IGBT6 by the gate driver 145 as a switching signal.

If the pulse signal generator 144 outputs a pulse width control signal with a reduced pulse width, the gate driver 145 can supply a less current to the motor. On the other hand, the pulse signal generator 144 generates a pulse width The output of the increased pulse width control signal allows the gate driver 145 to supply more current to the motor and consequently suppresses the output current imbalance caused by the voltage ripple of the film capacitor, So that uniform application is possible.

4 is a detailed block diagram of the offset generator of FIG.

Referring to FIG. 4, the offset generator of FIG. 2 includes a first amplifier 142-1 that receives a reference signal from the reference signal generator 141 and multiplies the reference signal by K1 and outputs the amplified signal, and a voltage ripple- And a multiplier 142-3 for multiplying the multiplied signal by a signal having passed through the first amplifier 142-1 and the second amplifier 142-2, .

According to such an offset generator, when an offset value proportional to the reference signal is outputted in proportion to the voltage ripple of the voltage across the film capacitor, a positive offset value is output in a section where the voltage ripple of the film capacitor is large, In the section where the voltage ripple of the capacitor is small, a negative offset value is output.

Meanwhile, FIG. 5 is a graph showing the current waveform at the output stage of the electrolytic capacitorless inverter driving apparatus according to an embodiment of the present invention.

Referring to FIG. 5, since the current waveforms are balanced, the output current imbalance caused by the voltage ripple of the film capacitor is suppressed, so that the torque of the motor can be uniformly applied.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification or improvement is possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: AC power supply 110:
120: Film capacitor 130: Inverter
140: control unit 141: reference signal generator
142: offset generator 142-1, 142-2: amplifier
142-3: multiplier 143: carrier signal generator
144: Pulse signal generator

Claims

A film capacitor for receiving and smoothing the power supply;
An inverter having a plurality of switching elements and converting a DC voltage output from the film capacitor into a motor driving voltage according to a control signal and outputting the converted DC voltage to a motor; And
And a control unit for generating a pulse width control signal by using a carrier signal and a reference signal in which an offset proportional to voltage ripple of the film capacitor is reflected, and outputting the pulse width control signal to the inverter.

The method according to claim 1,
Further comprising: a rectifier unit which is supplied with AC power and supplies DC power to the film capacitor.

The method according to claim 1,
The plurality of switching elements of the inverter
Switching elements IGBT1 and IGBT2 (IGBT3 and IGBT4) (IGBT5 and IGBT6) are connected in series between the power supply terminal and the ground, and the output terminals of the control section 140 are connected to the gates of the switching elements IGBT1 to IGBT6 And the connection point between the series-connected switching elements (IGBT1, IGBT2) (IGBT3, IGBT4) (IGBT5, IGBT6) is connected to the load.

The method according to claim 1,
Wherein the controller generates the offset value proportional to the voltage across ripple of the film capacitor when generating the offset value, and further to generate an offset value proportional to the reference signal.

The method of claim 4,
The control unit
A reference signal generator for generating a sine wave reference signal;
An offset generator for measuring a voltage at both ends of the film capacitor and outputting an offset value proportional to a voltage at both ends measured and proportional to a reference signal;
A carrier signal generator for generating a carrier signal which is a triangle wave in which an offset generated in the offset generator is reflected;
A pulse signal generator for generating a pulse width control signal by using a reference signal outputted from the reference signal generator and a carrier signal which is a triangle wave outputted from the carrier signal generator; And
And a gate driver for applying a switching signal corresponding to a pulse width control signal output from the pulse signal generator to each gate of the plurality of switching elements.

The method of claim 5,
Wherein the offset generator comprises:
A first amplifier that receives the reference signal from the reference signal generator and multiplies the reference signal by K1;
A second amplifier for receiving a voltage ripple of both ends of the voltage measured by the film capacitor and multiplying it by K2; And
And a multiplier for multiplying the signal having passed through the first amplifier and the signal having passed through the second amplifier and outputting the multiplied signal.