KR20130083500A - Single-stage battery charger without using electrolytic capacitors - Google Patents

Abstract

PURPOSE: A single-stage battery charger without using an electrolytic capacitor is provided to reduce switching loss, by using complementary switching operation. CONSTITUTION: A diode rectifier (100) generates a DC voltage with an AC voltage. A switching module (200) switches a plurality of switches complementarily. A voltage transformation module (300) boosts an output of the switching module and outputs the boosted output. A rectification module (400) performs voltage doubler rectification operation. A voltage and current control part controls an AC-DC converter.

Description

Single-stage battery charger without using electrolytic capacitors}

The present invention relates to a single-stage battery charger without an electrolytic capacitor, ZVS is possible in all duty areas to increase power efficiency and power density, single-stage battery charger that can improve the life of the product without using an electrolytic capacitor It is about.

In hybrid (HEV) and electric vehicles (EVs), chargers are mounted, which require high power density, low noise and high efficiency, and have a wide range of input voltages and battery operating voltages. 1 is a diagram illustrating a configuration of a single-stage battery charger. The charger according to FIG. 1 is composed of an AC-DC converter for power factor correction and voltage / current control of a battery. A conventional single stage AC-DC converter includes a boost full bridge converter employing an active clamp circuit as shown in FIG. 2. The converter achieves voltage clamp and zero voltage switching of the main element with only one clamp switch, but the additional clamp circuit increases the number of switches, and the switching frequency of the clamp switch doubles the switching frequency of the main switch, resulting in increased switching losses. There are disadvantages.

According to the present invention, the AC-DC converter performs zero voltage switching in all duty regions while simultaneously performing power factor correction and battery current control, thereby reducing switching loss and reducing the number of devices. The purpose is to improve the life of the product by using an electrolytic capacitor.

In the single-stage battery charger without an electrolytic capacitor according to the present invention, a diode rectifier for rectifying an AC voltage supplied from an external power source into a DC voltage, and receiving a rectified DC voltage to switch a plurality of switches to output a voltage A switching module configured to receive an output of the switching module, step up and output the output of the switching module, and a rectifying module configured to perform a voltage doubler rectification operation by receiving the output of the transformer module, wherein the switching module includes: It is connected to a diode rectifier for rectifying the AC voltage supplied from an external power source into a DC voltage, connected in series with the inductor, and connected in series with the first switch, the second switch, and the first switch connected in parallel with each other. And a second capacitor connected in series with a first capacitor and the second switch.

In addition, the transformer module is one end of the transformer primary side is connected in series with the inductor, the other end is connected between the first capacitor and the second capacitor, it is preferable that the transformer secondary side is connected to the rectifying module.

The rectifier module may include a first diode connected in series with one end of a secondary side of the transformer, a second diode connected in series with one end of a secondary side of the transformer and connected in parallel with the first diode, and the other side of the transformer. It is preferable to include a third capacitor connected in series with the stage, and a fourth capacitor connected in series with the tartan on the secondary side of the transformer and connected in parallel with the third capacitor.

The first switch and the second switch have a predetermined dead time, and are preferably driven complementarily by a switch driving signal input from the outside.

In addition, when one or more of the first switch and the second switch are switched, the switching module preferably operates in a duty range of 0 to 1 through a predetermined dead time.

The first switch and the second switch are complementary to each other, and the duty of the first switch and the second switch feeds back the externally supplied AC voltage, the inductor current, and the battery voltage according to the state of the battery. The voltage inputted to the battery to make it constant, and use the duty generated from the control unit controlling the AC-DC converter so that the inductor current has the same shape as the rectified AC voltage, or supply the supplied AC voltage and the inductor current and battery current. In response to the feedback, the current input to the battery is constant, and the duty generated by the control unit controlling the AC-DC converter is used so that the inductor current has the same shape as the rectified AC voltage.

In addition, it is preferable that the first capacitor and the second capacitor use a film capacitor as a clamp capacitor, and the third capacitor and the fourth capacitor are used as a film capacitor as a capacitor used to eliminate switching ripple. desirable.

The first switch and the second switch use a semiconductor device such as a metal oxide semiconductor field-effect transistor (MOSFET) or an IGBT.

According to the present invention, ZVS is possible in all duty regions of an AC-DC converter having a dead time and having a fluctuating duty through a complementary switching operation, thereby reducing switching losses.

In addition, the number of devices required to convert the input AC power source into the DC voltage or DC current input to the battery has a low cost effect.

In addition, since the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are all composed of a film capacitor, the life of the product is improved.

1 is a block diagram illustrating an overall configuration of a single-stage battery charger according to an embodiment of the present invention.
2 is a diagram illustrating a detailed circuit of a conventional single stage battery charger.
3 is a diagram illustrating a detailed circuit of a single-stage battery charger according to the present invention.
4 is a waveform illustrating ZVS operation according to a load condition of a single-stage battery charger according to the present invention.
5A to 5D are diagrams showing a current flow chart for each section of the single-stage battery charger according to the present invention.
6 is a view showing a waveform diagram for each section of a single-stage battery charger according to the present invention.
7A to 7B are circuit diagrams illustrating an extension of a single-stage battery charger according to the present invention.

Before describing the details for carrying out the present invention, it should be noted that configurations that are not directly related to the technical gist of the present invention are omitted within the scope of not distracting the technical gist of the present invention. It is also to be understood that the terminology or words used in the present specification and claims should be interpreted with reference to the meaning of the inventive concept of the present invention based on the principle that the inventor can define the concept of appropriate terms to describe his invention in the best way It should be interpreted as a concept.

A charger according to the present invention will be described with reference to FIG. In the case of a single-stage battery charger without an electrolytic capacitor according to the present invention, the diode rectifier 100 for rectifying the AC voltage 500 supplied from an external power source into a DC voltage, and receives the rectified DC voltage to complement a plurality of switches. A switching module 200 for switching and outputting a voltage, a transformer module 300 for receiving the output of the switching module 200 and stepping up and outputting the voltage, and a voltage doubler for receiving the output of the transformer module. Rectification module 400 to perform a rectifying operation, the switching module 200 is connected to the diode rectifier 100 for rectifying the AC voltage 500 supplied from the external power source to a DC voltage, inductor ( First and second switches S1 and S2 connected in parallel with each other in series with L1, and the first capacitor C1 and the second connected in series with the first switch S1, respectively. Switch (S2) And a second capacitor (C2) connected in series.

In addition, the transformer module 300 is one end of the transformer primary side is connected in series with the inductor (L1), the other end is connected between the first capacitor (C1) and the second capacitor (C2), the transformer secondary side is the rectification It is preferable to be connected to the module 400.

In addition, the rectifier module 400 may include a first diode D1 connected in series with one end of a secondary side of the transformer and a second diode connected in series with one end of a secondary side of the transformer and connected in series with the first diode ( D2), a third capacitor Co1 connected in series with the other end of the transformer, and a fourth capacitor Co2 connected in series with the tartan of the transformer secondary side and in series with the third capacitor. Do.

The first switch S1 and the second switch S2 have a predetermined dead time, and are preferably driven complementarily by a switch driving signal input from the outside.

In addition, when one or more of the first switch S1 and the second switch S2 are switched, the switching module 200 has a duty of 0 to 1 through a predetermined dead time. It is desirable to operate in the range.

In addition, the first switch S1 and the second switch S2 are complementary to each other, and the duty of the first switch S1 and the second switch S2 depends on the state of the battery 600. An AC voltage 500 supplied from an external source, the inductor L1 current and the battery 600 voltage are fed back to make the voltage input to the battery 600 constant, and the inductor L1 current is rectified to the AC voltage ( Using the duty generated from the control unit 800 that controls the AC-DC converter 700 to have the same shape as 500, or receiving feedback from the supplied AC voltage 500, the inductor L1 current, and the battery 600 current. The current input to the battery 600 is constant, and the duty generated from the controller 800 controlling the AC-DC converter 700 is used so that the inductor L1 current has the same shape as the rectified AC voltage 500. .

In addition, the first capacitor C1 and the second capacitor C2 preferably use a film capacitor as a clamp capacitor, and the third capacitor Co1 and the fourth capacitor Co2 eliminate switching ripple. It is preferable to use the film capacitor as the capacitor used to.

In addition, the first switch S1 and the second switch S2 use a semiconductor device such as a metal oxide semiconductor field-effect transistor (MOSFET) or an IGBT.

Next, a ZVS operation according to a load situation of a single-stage battery charger will be described with reference to FIG. 4. ZVS operation is performed in each load situation 500W to 3kW, and ZVS operation can be confirmed even at the duty of 0.39 to 0.54.

Next, an operation process according to an embodiment of the present invention will be described with reference to the accompanying drawings. 5A to 5D show a current flow charts for each section (t0 to t1, t1 to t2, t2 to t3, and t3 to t4) of the charger. The bold lines in FIGS. 5A to 5D mean current paths through which an actual current flows in each section t0 to t1, t1 to t2, t2 to t3, and t3 to t4. 6 shows a waveform diagram of a charger.

First, the operation in the t0 ~ t1 section of the single-stage battery charger without the electrolytic capacitor according to the present invention will be described with reference to FIGS. 5A and 6, when the switch SL is turned on, the ZVS Turn- On, the inductor (L) takes the input voltage and increases the current with a positive slope, and the leakage inductor (Lk) takes the voltage of -Vc3 / n-Vc2 and the current decreases with the negative slope and the leakage inductor (Lk) As the current of the diode (DU) becomes 0, it is turned off by ZCS turn-off of the diode (DU) and the section ends.

Second, the operation in the t1 ~ t2 section of the single-stage battery charger without the electrolytic capacitor according to the present invention with reference to Figures 5b and 6, the inductor (L) current is the same as the positive slope as before Is increased, the direction of the leakage inductor (Lk) current is changed, the sum of the inductor (L) current and the leakage inductor (Lk) current flows through the switch SL, and the section ends as the switch (SL) is turned off.

Third, the operation in the t2 to t3 section of the single-stage battery charger without the electrolytic capacitor according to the present invention will be described with reference to FIGS. 5C and 6, when the switch SU is turned on, the ZVS Turn- of the switch SU is turned on. on, Vin-Vc1-Vc2 is applied to the inductor (L) to decrease the current by a negative slope, and leakage inductor (Lk) is applied to the voltage of Vc4 / n + Vc1 to increase the current to a positive slope As the leakage inductor (Lk) current and the diode (DL) current becomes 0, they are turned off by the ZCS turn-off of the diode (DL) and the section ends.

Fourth, the operation in the t3 ~ t4 section of the single-stage battery charger without the electrolytic capacitor according to the present invention with reference to Figure 5d and 6, the inductor (L) current is the same as the negative slope as before The leakage inductor (Lk) current is also the same as the previous situation, the difference between the inductor (L) current and the leakage inductor (Lk) current flows through the switch (SU), the section ends as the switch (SU) is turned off.

The following describes an embodiment in which a single-stage battery charger without an electrolytic capacitor according to the present invention is applied to a multiphase.

≪ Embodiment 1 >

As shown in FIG. 7A, the switching module 200A according to the first embodiment of the present invention includes the first, second, ... N inductors L1, L2, ... LN connected in parallel with each other. A plurality of upper and lower switches S1 and S2 connected in parallel to each other and connected in series with the first, second, ... N inductors L1, L2, ... LN, respectively. , ... SN, S'1, S'2 ... S'N) and the upper and lower switches (S1, S2, ... SN, S'1, S'2, ... upper and lower capacitors C1, C2, ... CN, C'1, C'2, ... C'N connected in parallel to S'N, respectively.

In addition, the transformer module 300A includes the first, second, ... N inductors (L1, L2, ... LN) and the first, second, ... N transformers connected in series with each other. The other line of the transformer module 300A is connected between each of the upper and lower capacitors C1, C2, ... CN, C'1, C'2, ... C'N.

The rectifier module 200A is connected to the secondary side of each transformer and rectifies the voltage output from each transformer at the load side connected to the secondary side of each transformer.

Therefore, the rectifier module is connected to the secondary line of each transformer in series, the second terminal of each transformer is connected to the other, the upper and lower diodes (D1, D2, ... D3, D'1 , D'2, ... D'N) are respectively connected in parallel with the capacitors (Co1, Co2) connected in series with each other.

In addition, the switching module 200A divides the switching frequency into two so as to have a phase difference of 360 / N degrees during the complementary switching, so that the upper and lower switches S1, S2, ... SN, S'1, S'2. ... further includes a frequency control means (not shown) for outputting to S'N).

That is, the single-stage battery charger without the electrolytic capacitor according to the embodiment of the present invention shows the connection in the case of stretching to N phase, each phase has a phase difference of 360 / N.

Second Embodiment

As shown in FIG. 7B, the switching module 200B according to the second embodiment of the present invention includes a pair of inductors L11, L12,... L1P connected in parallel with each other, and connected in parallel with each other. And a plurality of upper and lower switches S11, S12, ... S1P, S'11 connected in series with the eleventh, 12, ... 1PN inductors L11, L12, ... L1P, respectively. , S'12 ... S'1P) and connected to each other in series to each of the upper and lower switches (S11, S12, ... S1P, S'11, S'12, ... S'1P) The upper and lower capacitors C11, C12, ... C1P, C 'connected in parallel are included.

In addition, the transformer module 300B includes eleventh, 12, ... 1P transformers in which the eleventh, 12, ... 1P inductors (L11, L12, ... L1P) and the primary side are connected in series with each other. The other line of the transformer module 300B is connected to the neutral line N1.

The rectifier module 400B is connected to the secondary side of each transformer and rectifies the voltage output from each transformer at the load side connected to the secondary side of each transformer.

Therefore, the rectifier module 400B is connected to a diode connected in series with one line of the secondary side of each transformer, and is connected to the secondary neutral line N2 line of each transformer, and the diodes D11, D12, ..., D1P , D'11, D'12, ..., D'1P) are respectively connected in parallel and at the same time have a capacitor (Co11, Co12) connected in series with each other.

In addition, the switching module 200B divides the switching frequency into two so as to have a phase difference of 360 / N degrees during the complementary switching, and thus the upper and lower switches S1, S2, ... SN, S'1, S'2. ... further includes a frequency control means (not shown) for outputting to S'N).

That is, the single-stage battery charger without the electrolytic capacitor according to the embodiment of the present invention shows the connection in the case of stretching to N phase, each phase has a phase difference of 360 / N.

100: diode rectifier 200: switching module
300: transformer module 400: rectification module
500: AC power 600: battery

Claims (7)

An AC-DC converter converting AC power into direct current; A diode rectifier 100 rectifying the AC voltage to produce a DC voltage; A switching module 200 that receives the rectified DC voltage and complementarily switches a plurality of switches to output a voltage; A transformer module 300 which receives the output of the switching module 200 and boosts the output of the switching module 200; Rectification module 400 for receiving the output of the transformer module 300 performs a voltage doubler rectification operation; And a voltage and current controller 800 for controlling the AC-DC converter to receive a voltage and a current of the AC power and a voltage and a current input to the battery so that the voltage or current input to the battery is constant.
The first capacitor and the second capacitor of the switching module 200 and the voltage doubler rectifier module 400 use a film capacitor as a clamp capacitor, and the third capacitor and the fourth capacitor provide switching ripple. Battery charger using film capacitors as capacitors used to remove
The switching module 200 includes a plurality of filter inductors connected in parallel to each other, a plurality of MOSFETs or IGBTs connected in parallel to each other, and connected in series with the plurality of filter inductors, respectively. A battery charger comprising a plurality of capacitors connected in series with each other and connected in parallel to the plurality of MOSFETs or IGBTs, respectively.
The battery charger according to claim 1, wherein the transformer module 300 includes a plurality of transformers connected in series with each other.
The battery charger of claim 1, wherein the voltage doubler rectifier module 400 includes a filter capacitor connected in parallel with a plurality of rectifier diodes connected in series with each other.
The battery charger of claim 1, wherein the switching module 200 has a predetermined dead time and is driven complementarily by a switch driving signal input from an external device.
The battery charger of claim 1, wherein the switching module 200 operates in a duty range of 0 to 1 through a predetermined dead-time.

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