KR101699451B1 - Converter For High Efficiency Charger Of Sencondary Battery, Charging System Having The Same and Operating Method Thereof - Google Patents

Abstract

The present invention relates to a converter device for a high-efficiency charger of a secondary battery, a charging system including the same, and an operation method thereof. The present invention is to minimize a converting loss by controlling DSP to mix two converter topologies in series and maximize an effective advantageous of each topology. According to the present invention, the converter device for a high efficiency charger of a secondary battery includes: a primary main switching unit (200) switching an input voltage; a secondary phase shift bridge (PSFB) rectification unit (310) outputting a regulated DC output voltage; a secondary half bridge (HB) LLC rectification unit (320) outputting a fixing DC output voltage by being connected to the secondary PSFB rectification unit (310) in series; and a control unit (400) outputting a control signal controlling the primary main switching unit (200) using a whole output voltage of the secondary rectification unit and controlling the secondary PSFB rectification unit (310) and the secondary HB LLC rectification unit (320) at the same time by single feedback.

Description

Technical Field [0001] The present invention relates to a converter device for a secondary battery high efficiency charger, a charging system including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter device for a secondary battery high efficiency charger, a charging system including the charging device and a driving method thereof, and more particularly, A topology control for increasing the efficiency of the converter, and a technique for the configuration thereof.

As interest in the environment increases, the demand for alternative resources that can replace existing harmful energy sources is increasing.

Many researches have been made on this, and development of alternative energy sources of automobiles, which are indispensable in modern life, is accelerating.

Electric vehicles have already been produced for the first time in the 1800s, but they have not become widespread due to limitations of technology and practicality.

However, as the quality of life has increased, studies on the internal combustion engines and the alternative energy sources have been conducted actively. have.

The electric vehicle includes an electric motor for driving the main body and a battery for supplying electric power to the motor, and a charging system for charging the battery is required.

The charging system changes the external AC power to a DC output, and can be divided into an internal charger provided inside the vehicle and an external charging device provided outside, depending on the position.

The internal charger provided in the interior of the vehicle is supplied with an AC input through an external cable as a charging system mounted on the vehicle.

Because the internal charger is mounted in a limited space of the vehicle and its weight is directly related to fuel economy, performance figures for power density and efficiency determine the competitiveness of the product. It is therefore important to make the size of the charger small.

The general charger converter includes a primary main switching unit 10 and a secondary rectifying unit 20 as shown in FIG.

However, the conventional charger converter has a single transmission path for all output currents.

As a result, there is a problem in that a transmission loss due to a resistance component existing in the circuit becomes large.

(Patent Literature 1) Korean Patent Laid-Open No. 10-2012-0012659 (published on October 10, 2012)
(Patent Document 2) Korean Patent Laid-Open No. 10-2012-0109914 (published on October 9, 2012)
(Patent Document 3) Korean Patent Laid-Open No. 10-2012-0111819 (published on October 11, 2012)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art described above, and it is an object of the present invention to provide a digital signal processor which combines two converter topologies serially and controls the digital signal processor so as to maximize the efficient advantages of each topology, The present invention provides a converter device for a secondary battery high efficiency charger which can minimize the loss, a charging system including the same, and a driving method thereof.

Another object of the present invention is to enable a quick response when a failure occurs by driving a converter device by a simple control method utilizing a digital signal processor.

Another object of the present invention is to simplify the control method of the converter device and to reduce the maintenance cost in the event of a failure.

The technical objects of the present invention are not limited to the above technical subjects, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a converter device for a secondary battery high efficiency charger, including: a primary main switching unit for switching an input voltage; A second phase shift full bridge (PSFB) rectifying part for outputting a variable DC output voltage; A secondary HB (Half Bridge) LLC rectifier connected in series with the secondary PSFB rectifier to output a fixed DC output voltage; And a control unit for outputting a control signal for controlling the primary main switching unit using the total output voltage of the secondary rectifying unit and simultaneously controlling the secondary PSFB rectifying unit and the secondary HB LLC rectifying unit with a single feedback .

In addition, the second PSFB (Phase Shift Full Bridge) rectifier and the second HB (Half Bridge) LLC rectifier may share the primary main switching unit.

The control unit may be configured to fix the output of the secondary HB LLC rectification unit and to control the output of the secondary PSFB rectification unit to fluctuate according to conditions.

In addition, the controller is a digital signal processor (DSP).

According to another aspect of the present invention, there is provided a method of driving a converter device for a secondary battery high efficiency charger, the method comprising: controlling a variation in output voltage of a charger converter according to a charge / Converting the DC voltage in the charger converter to a DC voltage for charging the battery in accordance with the control; And outputting a DC voltage for charging the battery.

The step of controlling the variation of the output voltage of the charger converter may include the steps of: fixing the output of the secondary rectifier HB (Half Bridge) LLC sharing the primary main switching unit; And controls the output to fluctuate according to the condition.

Meanwhile, a charging system according to the present invention includes a battery for driving a motor; And a charger including a charger converter for converting an externally applied voltage for charging the battery into a DC voltage for driving the motor.

The charger converter may further include: a primary main switching unit for switching an input voltage; A secondary PSFB rectifier for outputting a variable DC output voltage; A secondary HB LLC rectifier connected in series with the secondary PSFB rectifier to output a fixed DC output voltage; And a control unit for outputting a control signal for controlling the primary main switching unit using the total output voltage of the secondary rectifying unit and simultaneously controlling the secondary PSFB rectifying unit and the secondary HB LLC rectifying unit with a single feedback .

In addition, the secondary PSFB rectification unit and the secondary HB LLC rectification unit share the primary main switching unit.

According to the present invention, it is possible to combine two converter topologies in series and control the DSP so as to maximize the efficient advantage of each topology, thereby minimizing conversion loss.

Further, by controlling the switching circuit and the DSPf without adding a complicated circuit to the converter configuration and control, it is possible to simplify the method of dealing with defects from the development stage of the system, thereby reducing development cost and post-processing cost .

1 is a block diagram showing a configuration of a conventional charger converter.
2 is a block diagram showing a configuration of a charger converter according to an embodiment of the present invention.
3 is a detailed circuit diagram showing the configuration of the primary main switching unit of FIG.
4 is a circuit diagram showing a configuration of a secondary PSFB rectifier (Phase Shift Full Bridge) and a secondary HB (Half Bridge) LLC rectifier of FIG.
5 is a configuration diagram showing a detailed configuration of the control unit of FIG.
6A is an exemplary diagram of a charging system to which the charger converter of FIG. 2 is applied.
6B is another example of a charging system to which the charger converter of FIG. 2 is applied.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 2 to 6. FIG.

In describing the components according to the embodiments of the present invention, terms such as primary and secondary are intended to distinguish the components from other components, and the terms mean the nature, Order and the like are not limited.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The present invention relates to a DC-DC converter in a charging system for electric power such as an electric vehicle and an electric bicycle, in which two different topologies are simultaneously driven by one switching, Thereby reducing the transmission loss and maximizing the advantage of each topology.

FIG. 2 is a block diagram of a charger converter according to an embodiment of the present invention. The charger converter converts an input of an external AC power source to a DC output.

The charger converter according to the embodiment of the present invention includes a primary main switching unit 200, a secondary rectifying unit 300, and a control unit 400.

The primary main switching unit 200 is a full bridge switching device and has a detailed circuit configuration as shown in FIG.

As shown in FIG. 3, the primary main switching unit 200 includes switching elements Q1 to Q4 connected in a diagonal direction with respect to a transformer Trans.

The primary main switching unit 200 turns on / off the switching elements Q1 to Q4 at the same time to transfer energy, and sets the direct time ratio to the gate waveform to determine the degree of energy transfer according to the load.

The secondary rectifier 300 includes a secondary PSFB rectifier (Phase Shift Full Bridge) 310 and a secondary HB (Half Bridge) LLC rectifier 320 connected in series (the specific configuration of the secondary rectifier will be described later ).

The control unit 400 is a digital signal processor (DSP) that divides the variable output voltage DC_OUTV output from the second rectifying unit 300 and adjusts the duty by an internal PI operation to obtain 1 And outputs a switching control signal S_CTRL for controlling the main main switching unit 200.

That is, the control unit 400 does not control the outputs of the divided secondary rectifying unit 300, but controls the entire output by only one feedback, The configuration will be described later).

According to the charger converter of the present invention, the secondary rectification part 300 is connected in series with two circuits, and the output current is divided, thereby reducing the transmission loss.

Also, in the present invention, the PSFB rectifier (Phase Shift Full Bridge) 310 and the secondary HB (Half Bridge) LLC rectifier 320 share one primary main switching unit 200.

Accordingly, although two secondary rectification sections 300 are driven, the switching loss can be reduced compared with a combination configuration of two general switching circuits.

Hereinafter, the detailed configuration of the secondary rectifier 300 will be described with reference to FIG.

The secondary rectifier 300 includes a secondary PSFB rectifier 310 and a secondary HB LLC rectifier 320, as shown in FIG.

The secondary PSFB rectification unit 310 includes a switching unit 311, a transformer 312, and a rectification unit 313.

The switching unit 311 switches the fixed input voltage DC_IN supplied from the primary main switching unit 200 according to the phase difference.

The transformer 312 is connected between the switching unit 311 and the rectifying unit 313 to drop the output voltage of the switching unit 311. [

The rectifying unit 313 rectifies the output from the transformer 312 and converts it into a DC voltage.

In this case, the energy transfer method of the secondary PSFB rectifier 310 is the same as that of the FB (Full Bridge), but the phase ratio is changed by fixing the time ratio of each switch, The time ratio is determined.

In addition, the switching elements Q5 and Q6 (or Q7 and Q8) located on the same line are fixedly operated at a time ratio of about 50% with a phase difference of 180 degrees from each other so that an input terminal short is not generated. The phase is varied to adjust the total time ratio.

This method enables ZVS (Zero Voltage Switching), in which the charges stored in the capacitors C1 to C4 provided together with the switching elements Q5 to Q8 are discharged through resonance and can be turned on at 0V. The ZVS significantly reduces the switching loss and increases the efficiency of the entire system.

However, there is a disadvantage that the regulation is poor when the load is small and there is a transmission loss of the current flowing through the switching stage at the resonance of the ZVS period. As a result, the efficiency of the converter itself is up to 92 ~ 93%.

In order to overcome this disadvantage, the present invention adopts a hybrid type in which a secondary PSFB rectifier 310 and a secondary HB LLC rectifier 320 are connected in series as a complementary topology.

The secondary HB LLC rectification unit 320 includes a switching unit 321, a transformer 322, and a rectification unit 323.

The switching unit 321 switches the fixed input voltage DC_IN supplied from the primary main switching unit 200 according to the phase difference.

The transformer 322 is connected between the switching unit 321 and the rectifying unit 323 to drop the output voltage of the switching unit 321.

The rectifying unit 323 rectifies the output from the transformer 322 and converts it into a DC voltage.

By connecting the secondary PSFB rectification part 310 and the secondary HB LLC rectification part 320 in series, it is possible to realize a topology that can obtain the highest efficiency in the form of a converter that transfers energy in a resonance form.

However, in terms of practicality, the HB LLC has a limited input / output section, and the characteristic of the second HB LLC rectifier section changes depending on the resonance frequency and resonance inductors and capacitances.

For this reason, it is not easy to cope with wide input range, output voltage, and load fluctuation of modern converters.

In addition, the secondary HB LLC rectifier is mainly used for converters used only under certain conditions, and can not be used alone for chargers with sudden output voltage and load fluctuations.

However, according to the present invention, by arranging the secondary PSFB rectifying part 310 and the secondary HB LLC rectifying part 320 in series, it is possible to improve the efficiency of the secondary PSFB rectifying part 310 and improve the efficiency thereof and to use it universally.

The second HB LLC rectifying section 320 is difficult to operate in a wide input / output range, but can output the highest efficiency without affecting the load with a voltage gain of 1 at the resonance frequency.

That is, since the voltage gain is 1, the input voltage is transferred as it is and the conversion function disappears, but the operation having the most ideal efficiency characteristic can be utilized.

For example, while the input is fixed at 380V and the output is varied from 200V to 450, the LLC can output 200V at 200V output.

In other words, by designating the LLC operation range that can achieve the best efficiency in a specific section as one point, the converter can obtain the highest power gain possible and independent operation is possible because there is no need to control the frequency modulation It becomes.

In addition, the present invention is configured in series so that only the input 180V is changed from 50V to 220V in the PSFB.

In other words, only the advantage of the high power PSFB that can output the constant output in a relatively wide variety of input and output conditions through the time ratio adjustment is used in the converter.

The second HB LLC rectifying unit 320 independently outputs the input as it is without any special control. The second HB LLC rectifying unit 320 operates through the rate control at the feedback time in the second PSFB rectifying unit 310 only in the modulation period.

Since the second PSFB rectifier 310 is operated independently of the first and second PSFB rectifiers 310 and 310, it is possible to perform a serial configuration without a special auxiliary circuit at the secondary output terminals of the two topologies. It becomes possible.

Further, since the loss period of the secondary PSFB rectifying unit 310 is complemented by the secondary HB LLC rectifying unit and the narrow input / output period of the secondary HB LLC rectifying unit is supplemented by the PSFB, the high efficiency and the wide input / have.

5 is a configuration diagram showing a detailed configuration of the control unit 400 of FIG.

As shown in FIG. 5, the control unit includes a voltage distributor 410, a DSP controller 420, and a gate driver 430.

The voltage distributor 410 distributes the variable output voltage DC_OUTV output from the secondary rectifier 300 to a voltage.

The DSP control unit 420 adjusts the duty by an internal PI operation using a voltage-divided voltage by the voltage distribution unit 410.

The gate drive unit 430 outputs a switching signal S_CTRL for controlling the first main switching unit 200 by using the output signal of the DSP control unit 420.

In this case, although two switching circuits are operated, the frequency is fixed to the LLC resonance frequency, and an algorithm for controlling only the phase shift according to the output is applied.

The second HB LLC rectifier is a topology in which the voltage gain changes according to the frequency modulation. When operating at the resonant frequency, the gain is constant at 1 without fluctuation of the load.

Accordingly, the resonance frequency can be determined and fixed as the main switching waveform so as to be able to take charge of the fixed output, and only the phase of the PSFB stage at which the output is modulated can be controlled by modulating.

That is, it is possible to check not only the output of the divided secondary rectifier 300 but also the whole output by only one feedback.

In addition, the entire system can be simplified by depressurizing the output voltage according to the input of the controller 400 to accept the state of the output and determining the time ratio linearly through calculation.

With this simplified system, the convenience of development can be achieved and the repair of defects generated in production can be easily and quickly countered.

6A is an exemplary diagram of a charging system to which the charger converter of FIG. 2 is applied.

The charging system according to the embodiment of the present invention may include a battery 110 and an on-board charger 120 mounted in the electric vehicle 100. [

The battery 110 is a power source of the electric vehicle 100. The OBC 120 incorporates a charger converter of FIG. 2 that receives an AC input voltage from the outside and converts it to a DC voltage.

6B is another example of a charging system to which the charger converter of FIG. 2 is applied.

A charging system according to another embodiment of the present invention includes a battery 110 mounted in an electric vehicle 100 and an external charger 130 converts an AC input voltage to a DC voltage to charge the battery 110 .

At this time, the charger converter of FIG. 2 according to an embodiment of the present invention may be embedded in the charger 130. FIG.

According to the charger converter according to the embodiment of the present invention, the efficiency of the conventional 90% early stage can be increased by 3 to 5% or more.

Accordingly, the power density can be increased in a charger in which the limit of physical space and weight is important, and further, the performance of the entire vehicle can be improved.

In addition, by simply controlling the converter with a switching circuit and a DSP without adding a complicated circuit for configuration and control, it is possible to simplify the method of dealing with defects from the development stage of the system, thereby reducing the development cost and post-processing cost.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: Electric vehicle
110: Battery
120: OBC (On-Board Charger)
130: Charger
200: Primary main switching unit
300: Secondary rectifying part
310: Secondary Phase Shift Full Bridge (PSFB)
311:
312: Transformer
313:
320: Second Half Bridge LLC (HB LLC)
321:
322: Transformer
323: rectification part
400:
410:
420: DSP (Digital Signal Processor)
430:
Q1 to Q5: Switching element
C1 to C4: Capacitance

Claims (9)

1. A full bridge switching device comprising: a primary main switching unit 200 having switching elements Q1 to Q4 connected in a diagonal direction with respect to a transformer Trans to switch an input voltage;
A secondary PSFB (Phase Shift Full Bridge) rectifier 310 connected to the primary main switching unit 200 to output a variable DC output voltage;
A secondary HB (Half Bridge) LLC rectifier 320 connected in series with the secondary PSFB rectifier 310 to output a fixed DC output voltage; And
And outputs a control signal for controlling the primary main switching unit 200 using the total output voltage obtained by adding the output voltage of the secondary PSFB rectification unit 310 and the output voltage of the secondary HB LLC rectification unit 320, A control unit 400 for transferring a control signal to the primary main switching unit 200 as a single feedback to simultaneously control the secondary PSFB rectifying unit 310 and the secondary HB (Half Bridge) LLC rectifying unit 320; And a converter for a secondary battery high efficiency charger. The method according to claim 1,
Wherein the secondary PSFB rectification part (310) and the secondary HB LLC rectification part (320) share the primary main switching part (200). The method of claim 2,
The control unit (400)
And the output of the secondary HB LLC rectifying unit 310 is fixed and the output of the secondary PSFB rectifying unit 310 is controlled so as to vary according to conditions. The method according to claim 1,
Wherein the controller (400) is a digital signal processor (DSP). delete 1. A full bridge switching device comprising: a primary main switching unit 200 having switching elements Q1 to Q4 connected in a diagonal direction with respect to a transformer Trans to switch an input voltage;
A secondary PSFB (Phase Shift Full Bridge) rectifier 310 connected to the primary main switching unit 200 to output a variable DC output voltage;
A secondary HB (Half Bridge) LLC rectifier 320 connected in series with the secondary PSFB rectifier 310 to output a fixed DC output voltage; And
And outputs a control signal for controlling the primary main switching unit 200 using the total output voltage obtained by adding the output voltage of the secondary PSFB rectification unit 310 and the output voltage of the secondary HB LLC rectification unit 320, A control unit 400 for transferring a control signal to the primary main switching unit 200 as a single feedback to simultaneously control the secondary PSFB rectifying unit 310 and the secondary HB (Half Bridge) LLC rectifying unit 320; The method of driving a converter device for a secondary battery high efficiency charger,
Controlling an output voltage variation of the charger converter according to a charge / discharge state of the battery;
Converting the DC voltage in the charger converter to a DC voltage for charging the battery in accordance with the control; And
And outputting a DC voltage for charging the battery,
Wherein controlling the output voltage variation of the charger converter comprises:
(Half Bridge) LLC rectifying unit 320 that shares the primary main switching unit 200 and outputs the output of the secondary PSFB rectifying unit 310 according to conditions Wherein the control means controls the charging device to vary the charging current. delete A battery for driving the motor; And
And a charger converter for converting an externally applied voltage for charging the battery into a DC voltage for driving the motor, the charging system comprising:
The charger converter includes:
1. A full bridge switching device comprising: a primary main switching unit 200 having switching elements Q1 to Q4 connected in a diagonal direction with respect to a transformer Trans to switch an input voltage;
A secondary PSFB rectification unit 310 connected to the primary main switching unit 200 to output a variable DC output voltage;
A secondary HB LLC rectifier 320 connected in series with the secondary PSFB rectifier 310 to output a fixed DC output voltage; And
And outputs a control signal for controlling the primary main switching unit 200 using the total output voltage obtained by adding the output voltage of the secondary PSFB rectification unit 310 and the output voltage of the secondary HB LLC rectification unit 320, And a control unit (400) for transferring the control signal to the primary main switching unit (200) by a single feedback to simultaneously control the secondary PSFB rectification unit (310) and the secondary HB LLC rectification unit (320) Lt; / RTI > The method of claim 8,
Wherein the secondary PSFB rectification part (310) and the secondary HB LLC rectification part (320) share the primary main switching part (200).

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