KR20170059391A - Double sided resonant converter for wireless charger and method for implementing thereof - Google Patents

Abstract

The present invention relates to a double sided LCC converter for a wireless charger, capable of performing voltage transformation of an induction power transmission scheme between primary and secondary resonant tanks, and an implementing method thereof. According to the present invention, the converter comprises: a full-bridge inverter connected to input power supplying input voltage, and including first to fourth switches; an LCC resonant tank including primary and secondary resonant tanks individually having the same configuration which is composed of one resonant inductor and two resonant capacitors, and allowing the primary resonant tank to be connected to the full-bridge inverter to receive the input voltage, to perform the voltage transmission of the induction power transmission scheme between the primary and secondary resonant tanks; a rectification bridge connected to the secondary resonant tank to rectify output voltage transferred from the secondary resonant tank; and a load network connected to the rectification bridge to receive the rectified output voltage.

Description

TECHNICAL FIELD [0001] The present invention relates to a double-sided LCC converter for a wireless charger, and a method for implementing the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided LCC converter for a wireless charger and a method of implementing the same. More particularly, the present invention relates to a double-sided LCC converter for a wireless charger that realizes constant current and constant voltage charging and an implementation method thereof.

Most of electric vehicles (EVs) that have been commercialized in recent years have a plug-in type charging method. However, in comparison with such charging methods, inductive charging (IPT) Power transfer method has been suggested as a charging method for electric vehicles, and related researches have been actively conducted worldwide.

Unlike a conductive charger, an inductive power transfer charger uses a loosely coupled coils set instead of a transformer, and has a high reactive power due to a low coupling coefficient between the transmitting and receiving coils. And low power transmission efficiency. Therefore, in an inductive power transmission (IPT) charger, a compensation tank that can reduce such reactive power, improve power transmission capability and increase the overall efficiency is an important part.

This compensation topology can be divided into four types of series-serial (SS), serial-parallel (SP), parallel-serial (PS) and parallel-parallel (PP), depending on how compensation capacitors are added to the primary and secondary coils It can be divided. In addition, hybrid topologies can be used to increase power transfer efficiency and simplify control of an inductive power transfer (IPT) system.

For example, there is an LCL hybrid topology with an LC compensation network on the primary side. The added LC compensation tank can reduce the primary side current and reduce the conduction loss of the primary side switches. In addition, it has load-independent characteristics and can easily control the constant current at the output terminal. In addition, simple output power control is possible using a duty or phase shift control scheme. Alternatively, there is an LCCL topology in which one LC circuit is added in parallel to this LCL hybrid topology to minimize the circulating current of the receiving coil and achieve a unity power factor.

However, such LCL and LCCL hybrid topologies all require additional inductors having values similar to those of the coils on both sides, and in order to reduce the cost and the value of the inductor, a capacitor is connected in series to the primary coil The connected LCC compensation topology has been proposed. For example, there is a double-sided LCC topology with a capacitor added to the primary and secondary sides of the LCL topology, all of which have the advantages of LCL and LCCL topologies. This double-sided LCC topology is best suited to be applied to an inductive power transmission (IPT) system, since zero voltage switching conditions of the switching elements can be achieved and the resonant frequency is independent of coupling coefficient and load.

Another problem of the inductive power transmission (IPT) system is to realize a charging step according to a constant current (CC) and a constant voltage (CV) charging method in order to extend the life of the battery. The constant current / constant voltage charging method first charges the battery in the constant current mode to gradually increase the battery voltage. When the battery voltage reaches the maximum voltage, the battery is charged by switching to the constant voltage mode until the battery current reaches a specific value In order to realize such a charging step, the correct charging current and voltage must be provided from the charger. That is, since the battery being charged is a variable load, the converter included in the battery charger must be able to accurately control its output according to the constant current / constant voltage charging step.

In general, Pulse Width Modulation (PWM) is used to operate the converter at a fixed frequency, and Pulse Frequency Modulation (PFM) can be used to operate the converter at a fixed duty, A combination of the two methods can be used.

Here, as in the case of an inductive power transfer (IPT) converter, a power conversion system using a resonant operation requires a pulse frequency modulation system. As a result, a change in operating frequency over a wide range in accordance with a change in load is inevitable. Generates high circulating current in the converter, can not have zero voltage switching or zero current switching characteristics, increases power loss, and leads to a reduction in power transfer capability. In addition, branching phenomena may occur where control capability and system stability are lost. To overcome this disadvantage, a back-end DC-DC converter is added to control the output current and voltage, and a front-end DC-DC converter operates at a resonant frequency to produce a zero phase angle ZPA (Zero Phase Angle) condition has been proposed, but there is a problem that the number of components increases, and loss and complexity increase.

On the other hand, in order to solve the frequency fluctuation problem of the resonance frequency under the load condition varying in a wide range when realizing the constant current / constant voltage charging method in the charger, a study on utilizing the load- . For example, of the serial-to-serial (SS), serial-parallel (SP), parallel-serial (PS), and parallel- parallel (PP) topologies described above, the PS topology is capable of implementing a constant voltage charging scheme, It is possible to implement a constant current charging method. In addition, both SS and SP topologies are capable of both constant current and constant voltage charging. For SS topology, when operating in constant voltage charging mode, the SP topology loses zero phase angle (ZPA) condition when operating in constant current charging mode.

Recently, dual topologies of SS and PS, or SP and PP topologies have been proposed to achieve zero phase angle (ZPA) conditions at all stages of constant current / constant voltage charging. For example, the double-sided LCC topology described above can operate at a resonant frequency to ensure output of a load-independent current and voltage under zero phase angle (ZPA) conditions, but a switch element and a control circuit for topology switching must be added do.

One aspect of the present invention is to perform voltage conversion of an inductive power transmission system between a primary resonance tank and a secondary resonance tank, which are constituted by one resonance inductor and two resonance capacitors, respectively, and each including a primary coil and a secondary coil Side LCC converter for a wireless charger.

Another aspect of the present invention provides a method for implementing a double-sided LCC converter for a wireless charger that implements an LCC resonance tank by calculating parameters of resonance elements included in an LCC resonance tank for realizing constant current and constant voltage charging under zero phase angle conditions .

One aspect of the present invention is a double-sided LCC converter for a wireless charger, comprising: a full-bridge inverter connected to an input power supply for supplying an input voltage and having first to fourth switches; and a first resonant inductor and two resonant capacitors Side resonance tank and the secondary-side resonance tank, the primary-side resonance tank being connected to the full-bridge inverter and receiving the input voltage, and the inductive power between the primary-side resonance tank and the secondary-side resonance tank A rectifying bridge connected to the secondary side resonance tank for rectifying an output voltage received from the secondary side resonance tank, and a rectifier bridge connected to the rectifying bridge for receiving a rectified output voltage, Network.

The LCC resonant tank may include a primary resonant inductor connected to the full bridge inverter, a first primary resonant capacitor and a second primary resonant capacitor connected to the primary resonant inductor, a first primary resonant capacitor, Side resonance capacitor connected to the first primary side resonance capacitor, a primary side resonance tank composed of a primary side coil connected to the second primary side resonance capacitor, a secondary side resonance inductor connected to the rectification bridge, a first secondary side resonance capacitor connected to the secondary side resonance inductor, And a secondary side resonance tank composed of a secondary side coil connected to the first secondary side resonance capacitor and the second side resonance capacitor.

In addition, the self inductance of the primary coil and the secondary coil can be set to be the same.

In addition, the LCC resonance tank can output a constant current regardless of the change of the load network when the LCC resonant tank operates under a constant current mode frequency condition of a fixed frequency.

In addition, the LCC resonance tank, when operating under the constant current mode frequency condition, achieves the zero phase angle condition of the input impedance so that the first switch to the fourth switch provided in the full bridge inverter performs the switching operation Can be performed.

In addition, the LCC resonance tank can output a constant voltage regardless of the change of the load network when the LCC resonant tank is operated under a constant frequency mode frequency condition, which is a fixed frequency.

In addition, the LCC resonance tank, when operating under the constant voltage mode frequency condition, achieves the zero phase angle condition of the input impedance so that the first to fourth switches provided in the full bridge inverter can perform the switching operation Can be performed.

In another aspect of the present invention, there is provided an inductive power transmission type voltage conversion between a primary resonance tank and a secondary resonance tank, the resonance inductor including two resonance inductors and two resonance capacitors and including a primary coil and a secondary coil, Side resonance tank for transmitting a voltage of an input terminal connected to the primary-side resonance tank to an output terminal connected to the secondary-side resonance tank, the method for implementing a double-side LCC resonance converter for a wireless charger, A constant current mode frequency which is an operating frequency in a constant current mode for outputting a constant magnitude current to the output terminal is set in consideration of the size and loss of the resonance elements included in the tank and the size of the primary coil and the secondary coil And the mutual inductance of the primary coil and the secondary coil, the primary coil and the phase The inductance of each of the secondary coils is set, and the mutual inductance of the primary coil and the secondary coil, the self inductance of each of the primary coil and the secondary coil, the constant current mode frequency, And the inductance or capacitance of the resonant elements included in the LCC resonant tank is calculated according to the magnitude of the output current to be output. According to the inductance or capacitance of the resonant elements included in the calculated LCC resonant tank, Voltage condition for operating the constant-voltage mode for outputting a voltage under a constant-voltage-mode frequency condition, which is an operating frequency, to verify whether or not the zero-phase angle condition of the input impedance of the LCC resonance tank is satisfied, Self inductance of each of the coils, And implementing the LCC resonant tank according to the inductance or capacitance of the resonant elements included in the true tank.

The primary resonance tank may further include a first bridge, a fourth bridge, and a fourth bridge connected to the input of the full-bridge inverter for transmitting the input voltage to the LCC resonance tank.

The secondary resonance tank may further include a first diode to a fourth diode provided at the output terminal and connected to a rectifying bridge for rectifying the output of the LCC resonance tank.

The mutual inductance of the primary coil and the secondary coil, and the self inductance of each of the primary coil and the secondary coil are set according to the size and weight of the primary coil and the secondary coil, And the self inductance of each of the secondary coil and the secondary coil may have the same value.

The inductance of each of the primary coil and the secondary coil, the constant current mode frequency, the input voltage supplied from the input terminal, and the magnitude of the output current to be outputted are determined by the inductance of the primary coil and the secondary coil, The inductance or the capacitance of the resonant elements included in the LCC resonance tank may be calculated by calculating the inductance or capacitance of the resonant elements included in the LCC resonance tank so as to satisfy the zero phase angle condition of the input impedance of the LCC resonant tank under the constant- It may be to calculate the inductance or capacitance of the devices.

In addition, setting the constant current mode frequency, which is an operation frequency in a constant current mode for outputting a constant magnitude current to the output terminal, considering the size and loss of the resonant elements included in the LCC resonance tank, It may be to set the mode frequency.

According to the calculated inductance or capacitance of the resonance elements included in the LCC resonance tank, the input impedance of the LCC resonance tank under a constant voltage mode frequency condition, which is an operation frequency in a constant voltage mode for outputting a constant magnitude voltage to the output terminal, Verifying whether or not the zero phase angle condition of the LCC resonance tank satisfies the zero phase angle condition of the input impedance of the LCC resonance tank under the constant voltage mode frequency condition of the fixed frequency.

The implementation of the LCC resonance tank according to the self inductance of each of the primary coil and the secondary coil and the inductance or capacitance of the resonance elements included in the LCC resonance tank according to the result of the verification can be realized by the LCC When the inductance or the capacitance of the resonance elements included in the resonance tank satisfies the zero phase angle condition of the input impedance of the LCC resonance tank under the constant voltage mode frequency condition, the self inductance of each of the primary coil and the secondary coil, The inductance or the capacitance of the resonant elements included in the LCC resonance tank is set to be equal to or less than the inductance or the capacitance of the LCC resonance tank under the constant voltage mode frequency condition, Input Impedance of Tank The inductance of each of the primary coil and the secondary coil, the inductance of each of the primary coil and the secondary coil, depending on the size and weight of the primary coil and the secondary coil until the zero phase angle condition is satisfied, ≪ / RTI >

According to one aspect of the present invention, since the constant current and the constant voltage charging can be performed under the fixed frequency condition regardless of the change in the load, the control is simple and the stability of the charger can be ensured.

1A to 1D are diagrams showing an AC equivalent circuit of basic topologies for performing voltage conversion of an inductive power transmission system.
2A and 2B are schematic circuit diagrams of a double-sided LLC converter according to an embodiment of the present invention.
3 is a diagram illustrating an M model of a double-sided LCC converter according to an embodiment of the present invention.
FIG. 4 is a simplified view of an M model of a double-sided LCC converter according to an embodiment of the present invention shown in FIG.
FIGS. 5A and 5B are simplified views of an equivalent circuit of a double-sided LCC converter according to an embodiment of the present invention shown in FIG. 2B.
6 and 7 are simplified views of an equivalent circuit of a double-sided LCC converter according to an embodiment of the present invention in accordance with a change in input impedance.
8 is a flowchart illustrating a method of implementing a two-sided LCC converter according to an embodiment of the present invention.
9A and 9B are views illustrating an example of measuring transconductance gain and voltage gain according to the input impedance of the double-sided LCC converter according to an embodiment of the present invention.
10 is a diagram illustrating an example of a battery charging profile and equivalent impedance of a battery of a double-sided LCC converter according to an embodiment of the present invention.
11 is a diagram illustrating an example of an inductive power transmission pad applied to a double-sided LCC converter according to an embodiment of the present invention.
12A to 15 are diagrams for explaining advantageous effects of a double-sided LCC converter according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

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

First, the characteristics of the basic topologies for performing the inductive power transfer (IPT) voltage conversion will be described with reference to FIGS. 1A to 1D. In the first embodiment of the present invention implemented as a combination of these basic topologies The double-sided LCC converter according to the present invention will be described.

FIGS. 1A to 1D are diagrams showing AC equivalent circuits of basic topologies for performing voltage conversion of an inductive power transmission system.

(SS), a series-parallel (SP), a parallel-series (PS), and a series-parallel (PS) according to the positions where the compensation capacitors C _p and C _s are added to the primary side and the secondary side, And parallel-parallel (SS) are the basic topologies. L ₁ and L ₂ denote the primary and secondary self-inductances, M denotes the mutual inductance, L _p and L _s denote the primary and secondary sides, respectively, L _m is the magnetization inductance of the coil, C _p And C _s represent the compensation capacitances of the primary and secondary sides, respectively. At this time, the turn ratio between the two coils may be 1: n.

In the case of the SS topology shown in FIG. 1A, the resonant frequency required to achieve the zero phase angle (ZPA) condition is expressed by Equation 1 below.

[Equation 1]

Here, when the SS topology shown in FIG. 1A _{operates at} the frequency of f _{CC_SS} , L ₁ (L _m + L _p ) and L ₂ (L _m + L _s ) are connected to the primary side compensation capacitance C _p and the secondary side When completely compensated by the compensation capacitance (C _s ), the output current I _o can have a load-independent characteristic and the phase of the input impedance can be equal to zero. That is, the SS topology shown in FIG. 1A can operate as a CC (Constant Current) mode for constant current charging when operating at the frequency of f _{CC_SS} , and can achieve the zero phase angle (ZPA) condition.

The SS topology shown in FIG. 1A has two resonant frequencies. The resonant frequencies other than Equation (1) are the frequencies for outputting a constant voltage regardless of the load condition, that is, a constant voltage (CV) Mode can be expressed as Equation (2) below. &Quot; (2) " This CV mode frequency is usually chosen to be a high frequency, so that the resonant tank operates in an inductive region and the primary switches can operate under Zero Voltage Switching (ZVS) conditions .

&Quot; (2) "

However, the SS topology shown in FIG. 1A has the following disadvantages when operating at the CV mode frequency as shown in Equation (2). First, the high turn-off current due to the large phase of the input impedance under light load conditions increases the switching losses and reduces the efficiency. In addition, conduction loss due to large reactive power is increased, and power transmission efficiency is reduced.

In the case of the SP topology shown in FIG. 1B, it can operate as a CC mode and a CV mode, similar to the SS topology. That is, in the SP topology shown in FIG. 1B, at a frequency where the primary-side compensation capacitance C _p resonates with L ₁ -L ² _m / L ₂ , the input impedance becomes resistive and the output becomes a load- have.

Meanwhile, the SP topology shown in FIG. 1B can operate as a load-independent current source when operating at the frequency as shown in Equation (3) below. Specifically, the SP topology shown in FIG. 1B can operate as a CC mode when operating at the frequency shown in Equation 3 below.

&Quot; (3) "

In this case, the input impedance of the SP topology shown in FIG. 1B can be expressed by Equation (4) below.

&Quot; (4) "

If the resonance is made between Equation 4 primary compensation capacitance (C _p) and primary side leakage inductance (L _p), the secondary compensation capacitance (C _s) and the secondary side leakage inductance (L _s), Equation (4) below And the phase of the input impedance can be expressed by Equation (6). &Quot; (6) "

&Quot; (5) "

&Quot; (6) "

According to Equation (6), since the phase of the input impedance always has a positive value, the SP topology shown in FIG. 1B operates in an inductive region, so that the primary switches have a high turn-off current, A large circulating current is generated and the overall efficiency is lowered.

On the other hand, unlike the SS and SP topologies, the PS topology shown in FIG. 1C and the PP topology shown in FIG. 1D can operate only as the CV mode and the CC mode, respectively. Table 1 below shows whether the realization of constant current and constant voltage charging of the four basic inductive power transmission topologies shown in Figures 1A-1D and whether zero phase angle (ZPA) conditions can be achieved.

Topology Possible charge mode to implement
ZPA
Angular Resonant Frequency
SS
CC
Yes

CV
No

SP
CC
No

CV
Yes

PS
CV
Yes

and

PP
CC
Yes

and

According to Table 1, each of the four basic inductive power transfer topologies shown in Figs. 1A to 1D realizes both constant current and constant voltage charging, and can not achieve the zero phase angle (ZPA) condition. Thus, the double-sided LCC converter 1000 according to an embodiment of the present invention can be configured to provide a combination of the basic inductive power transmission topologies shown in Figs. 1A-1D to realize constant voltage and constant current charging under zero phase angle (ZPA) Lt; / RTI > This will be described with reference to Figs. 2A and 2B.

2A and 2B are schematic circuit diagrams of a double-sided LLC converter according to an embodiment of the present invention.

2A, a double-sided LCC converter 1000 according to an embodiment of the present invention may include a full bridge inverter 110, an LCC resonant tank 120, a rectifier bridge 130, and a load network 140 have. The two-sided LCC converter 1000 according to an exemplary embodiment of the present invention is a converter for a battery charger that supports wireless charging. The converter 200 converts an input voltage V _in to an inductive power transmission method to generate an output load R _o , It is possible to realize the constant current / constant voltage charging of the battery under the zero phase angle (ZPA) condition. Hereinafter, each component of the double-sided LCC converter 1000 according to an embodiment of the present invention will be described in detail.

First, the full-bridge inverter 110 includes a first switch (S ₁₎ to the fourth switch to the full-bridge circuit provided with a (S _4), this first switch (S ₁₎ to the switching operation of the fourth switch (S ₄₎ The DC input voltage V _in may be converted into an AC voltage and transmitted to the LCC resonant tank 120.

The LCC resonant tank 120 can be largely divided into a primary resonant tank and a secondary resonant tank. The primary resonant tank may be connected to the full bridge inverter 110, and the secondary resonant tank may be connected to the rectifier bridge 130. And can perform voltage conversion of the induction power transfer system between the primary resonance tank and the secondary resonance tank.

Specifically, the primary resonance tank may include a primary resonance inductor 121, a first primary resonance capacitor 122, and a second primary resonance capacitor 123. At this time, the first primary resonant capacitor 122 and the second primary resonant capacitor 123 may be connected in parallel with the primary coil 124 in series. In other words, one end of the first primary resonant capacitor 122 is connected to one end of the second primary resonant capacitor 123, and the other end of the first primary resonant capacitor 122 is connected to one end of the primary coil 124 And the other end of the primary winding 124 may be connected to the other end of the second primary-side resonant capacitor 123. One end of the first primary resonant capacitor 122 and one end of the second primary resonant capacitor 123 may be connected to the primary resonant inductor 121. Such a primary resonance tank may be implemented on an input voltage line connecting a pair of legs constituting the full bridge inverter 110. That is, the other ends of the primary resonance inductor 121 and the second primary resonance capacitor 123 may be connected to the full bridge inverter 110, respectively.

The secondary-side resonance tank may be configured in the same manner as the primary-side resonance tank, and may be constituted by the secondary-side resonance inductor 128, the first secondary-side resonance capacitor 126, and the second secondary-side resonance capacitor 127. At this time, the first secondary-side resonant capacitor 126 and the second secondary-side resonant capacitor 127 may be connected in parallel with the secondary coil 125 in series. In other words, one end of the first secondary-side resonant capacitor 126 is connected to one end of the second secondary-side resonant capacitor 127, and the other end of the first secondary-side resonant capacitor 126 is connected to one end of the secondary coil 125 And the other end of the secondary coil 125 may be connected to the other end of the second secondary-side resonant capacitor 127. One end of the first secondary-side resonant capacitor 126 and one end of the second secondary-side resonant capacitor 127 may be connected to the secondary-side resonant inductor 128. Such a secondary-side resonant tank may be implemented on an output voltage line connecting a pair of legs constituting the rectifying bridge 130. That is, the other ends of the secondary resonance inductor 128 and the second secondary resonance capacitor 127 may be connected to the rectifying bridge 130, respectively.

As described above, the LCC resonance tank 120 may have a configuration in which resonance tanks each composed of one resonance inductor and two resonance capacitors are provided on both sides of the primary and secondary sides, respectively. L ₁ and L ₂ denote the self inductances of the primary and secondary resonance tanks respectively, L _rp and L _rs denote the leakage inductances of the primary and secondary resonance tanks, k is 1 M is a coupling coefficient between the primary side coil 124 and the secondary side coil 125, M is a mutual inductance between the primary side coil 124 and the secondary side coil 125, and L _m is a magnetization inductance of the coil.

Assuming that the number of turns of the primary side coil 124 and the secondary side coil 125 is the same for convenience of explanation, the self inductance L ₁ of the primary resonance tank and the self inductance L (L ₁ ) of the secondary resonance tank _2), the relationship between the coupling coefficients (coupling coefficient) of the primary-side resonant tank leakage inductance (L _rp) and the secondary side resonance leakage inductance of the tank (L _rs), the primary coil 124 and secondary coil 125 of the Can be expressed by Equation (7) below.

&Quot; (7) "

2B is an AC equivalent circuit of the double-sided LCC converter 1000 according to an embodiment of the present invention. Referring to FIG. 2B, the first harmonic components can be expressed by the following Equation 8 have.

&Quot; (8) "

In Equation 8 V, and V _{o in_AC _AC} each input and output voltage, the output current i _{O_AC,} R _AC indicates the size of the load resistance.

The two-sided LCC converter 1000 according to an embodiment of the present invention can be realized to realize the constant current / constant voltage charging of the battery under the condition of the phase value (ZVS) when the LCC resonance tank 120 is implemented. A detailed description thereof will be given later.

Again, referring to Figure 2a, the rectifier bridge 130 is a first diode (D ₁₎ through the fourth diode (D ₄₎ is to provided full bridge circuit, a first diode (D ₁₎ through the fourth diode (D ₄ Side resonance tank of the LCC resonance tank 120 and can transmit the rectified voltage to the load network 140.

The load network 140 consists of an output capacitor C _o and a load resistor R _o connected in parallel, where the load resistance R _o can be a battery. Both ends of the output capacitor C _o are respectively connected to the upper contact and the lower contact of the full bridge circuit constituting the rectifying bridge 130 and can receive the rectified output voltage through the rectifying bridge 130.

Hereinafter, operational characteristics and advantageous effects of the double-sided LCC converter 1000 according to an embodiment of the present invention will be briefly described. For convenience of explanation, it will be analyzed in the frequency domain based on first harmonic approximation (FHA).

First, in order to obtain a maximum basic output voltage, the double-sided LCC converter 1000 according to an embodiment of the present invention preferably operates the switches provided in the full-bridge inverter 110 with a duty ratio of approximately 50%.

Also, in the double-sided LCC converter 1000 according to an embodiment of the present invention, the current flowing through the primary coil 124 is constant regardless of the load and the coupling condition, and therefore, the output control at the primary side can be simplified .

In addition, the double-sided LCC converter 1000 according to an embodiment of the present invention can achieve a unit power factor in both the primary and secondary sides, thereby minimizing the circulation current in both sides.

1A is compared with the SS topology shown in FIG. 1A, voltage and current stresses of the series-connected resonant capacitors and coils provided in the LCC rectification tank 120 are compared with each other Thereby making it possible to use components with a low rating and to reduce conduction loss.

Finally, the magnetization inductance value of the coil also changes according to the change in the distance or misalignment between the coils. The double-sided LCC converter 1000 according to an embodiment of the present invention has such a change .

Hereinafter, with reference to FIG. 3 and FIG. 4, a description will be made of a method of implementing the double-sided LCC converter 1000 according to an embodiment of the present invention for realizing constant current charging of the battery under the zero phase angle (ZPA) condition do.

3 is a view showing an M model of a double-sided LCC converter according to an embodiment of the present invention, and FIG. 4 is a view schematically showing an M model of a double-sided LCC converter according to an embodiment of the present invention shown in FIG. 3 .

As described above, the double-sided LCC converter 1000 according to an embodiment of the present invention can be included in the battery charging apparatus to realize battery charging in a constant current (CC) charging mode. That is, the double-sided LCC converter 1000 according to an embodiment of the present invention can operate as a current source to perform constant current charging of a battery connected to an output terminal. In this case, the double-sided LCC converter 1000 according to an embodiment of the present invention can perform constant current charging of the battery under the zero phase angle (ZPA) condition. To this end, the LCC resonance tank 120) must be implemented. L ₁ and L ₂ denote the self inductances of the primary and secondary resonance tanks respectively, L _rp and L _rs denote the leakage inductances of the primary and secondary resonance tanks, k is 1 M is the coupling inductance between the primary coil 124 and the secondary coil 125, L _m is the magnetization inductance of the coil, and? Is the resonant inductance of the coil angular frequency (angular resonant frequency), I _in is the input current, I _o is the output current, I ₁ is the current of the primary coil (124), I ₂ is the secondary side coil 125, current, L _1p And L _1s are the inductances of the primary resonant inductor 121 and the secondary resonant inductor 128 and C _1p and C _2p are the inductances of the first primary resonant capacitor 122 and the second primary resonant capacitor 123, The capacitances C _1s and C _2s are the capacitances of the first secondary-side resonant capacitor 126 and the second secondary-side resonant capacitor 127, respectively, and R _AC represents the magnitude of the load resistance.

3, a method of implementing the LCC resonant tank 120 for performing the constant current charging of the battery under the zero phase angle (ZPA) will be described in detail. First, in an embodiment of the present invention shown in FIG. 3 The Kirchhoff's law can be applied to the M model of the double-sided LCC converter 1000. As a result, the primary-side voltage expression of the LCC resonant tank 120 can be expressed by Equation (9) below.

&Quot; (9) "

Further, the secondary voltage equation of the LCC resonance tank 120 using the Kirchhoff's law can be expressed by the following equation (10).

&Quot; (10) "

From Equations (9) and (10), it can be predicted that the input voltage (V _in ) can be represented only by the output current (I _o ) and the impedance as shown in the following Equation (11). In this case, the components of the LCC resonance tank 120 must satisfy the following equations (12) and (13).

&Quot; (11) "

&Quot; (12) "

&Quot; (13) "

It can be seen from Equation 11 that the output current I _o is determined by the input voltage V _in , the operating frequency and the parameters of the LCC resonant tank 120, The LCC converter 1000 can operate as a current source when operating under the CC mode frequency condition, and consequently a constant current charging of the battery connected to the output stage is possible.

Meanwhile, in order to find the condition for performing the constant current charging of the battery under the zero phase angle (ZPA) condition, the double-sided LCC converter 1000 according to an embodiment of the present invention requires the LCC resonance tank 120, The impedance of the secondary side shall be calculated. At this time, the impedance of the secondary side of the LCC resonance tank 120 can be calculated using Equation (13).

&Quot; (14) "

The impedance of the secondary side of the LCC resonance tank 120 can be expressed by the impedance of the primary side of the LCC resonance tank 120 as shown in Equation (15) below.

&Quot; (15) "

From Equation (15), the equivalent circuit of M shown in Fig. 3 can be schematically shown as shown in Fig.

Referring to FIG. 4, the input impedance (Z _in ) of the double-sided LCC converter 1000 according to an embodiment of the present invention can be expressed by Equation (16) below.

&Quot; (16) "

From Equation (16), it can be confirmed that the imaginary part of the input impedance must be 0 in order to achieve the zero phase angle (ZPA) condition at the resonant frequency.

Here, according to Equation (12), when the double-sided LCC converter 1000 according to an embodiment of the present invention operates in the CC mode, it can be confirmed that the imaginary part of the first term on the right side of Equal sign of Equation 16 becomes zero. Therefore, only the imaginary part of the second term from the right side of Equation 16 should satisfy 0. For this reason, the second term to the right of Equation 16 on the right side is expressed in the following Equation 17 below.

&Quot; (17) "

Here, when the angular resonant frequency of the CC mode satisfies the following equations (18) and (19), it can be confirmed that only the real part remains in the equation (17).

&Quot; (18) "

&Quot; (19) "

Accordingly, in order for the double-sided LCC converter 1000 according to the embodiment of the present invention to perform the constant current charging of the battery under the zero phase angle (ZPA) condition, the LCC resonance tank 120 is formed by the above- And 19, where the CC mode resonance angular frequency can be expressed as: < EMI ID = 20.0 >

&Quot; (20) "

Hereinafter, with reference to FIG. 5A to FIG. 7, a description will be made of a method of implementing the double-sided LCC converter 1000 according to an embodiment of the present invention for realizing the constant-voltage charging of the battery under the zero phase angle (ZPA) do.

FIGS. 5A and 5B are simplified views of an equivalent circuit of the double-sided LCC converter according to an embodiment of the present invention shown in FIG. 2B. FIG. 6 and FIG. 1 is a diagram schematically showing an equivalent circuit of a double-sided LCC converter according to a first embodiment of the present invention.

As described above, the double-sided LCC converter 1000 according to an embodiment of the present invention can be included in the battery charging apparatus to realize battery charging in a constant voltage (CV) charging mode. That is, the double-sided LCC converter 1000 according to an embodiment of the present invention may operate as a voltage source to perform constant-voltage charging of a battery connected to an output terminal. Here, the double-sided LCC converter 1000 according to the embodiment of the present invention can perform the constant-voltage charging of the battery under the zero phase angle (ZPA) condition. Before explaining the implementation method of the LCC resonance tank 120 for this, It is assumed that the resonance components of the primary side and the secondary side of the LCC resonance tank 120 have the same value as shown in Equation 21 below. One of the characteristics of the double-sided LCC converter 1000 according to an embodiment of the present invention is that the voltage gain is almost unity. From this characteristic, the self inductance of the primary coil 124 is determined by the inductance of the secondary coil 125 (L &_lt; ₁ > = L < ₂ >).

&Quot; (21) "

In order to explain the method of implementing the LCC resonant tank 120 for performing the constant-voltage charging of the battery under the zero phase angle (ZPA) condition, as shown in FIG. 5A, The equivalent circuit of the double-sided LCC converter 1000 is briefly shown, and the .gamma. -.DELTA. Conversion is applied to the equivalent circuit of FIG. 5A to simplify the circuit as shown in FIG. 5B. At this time, the values of the respective impedances in Figs. 5A and 5B are as shown in Equation 22 below.

&Quot; (22) "

The Kirchhoff law can be applied to the equivalent circuit of the double-sided LCC converter 1000 according to an embodiment of the present invention shown in FIG. 5B. As a result, the double-sided LCC converter 1000 according to an embodiment of the present invention The voltage gain can be expressed by Equation 23 below.

&Quot; (23) "

According to Equation 23, when the following Equation 24 is satisfied in the angular resonant frequency of the CV mode, it can be confirmed that the voltage gain G _V is constant regardless of the load resistance R _AC .

&Quot; (24) "

That is, the double-sided LCC converter 1000 according to an embodiment of the present invention can operate as a voltage source under the CV mode frequency condition when it is implemented to satisfy Equation 25 or 26 below, Constant voltage charging of the battery is possible.

&Quot; (25) "

&Quot; (26) "

와 같이 산출될 수 있고, 입력 임피던스는 아래의 수학식 27과 같이 나타낼 수 있다.On the other hand, according to Equation (25), when Z ₁₃ = 0 in FIG. 5B, FIG. 5B can be redrawn as shown in FIG. In this case, the impedance of the LCC resonance tank 120 is

And the input impedance can be expressed by Equation 27 below. &Quot; (27) "

&Quot; (27) "

Here, according to equations (22) and (23), it can be confirmed that Z ₁₂ , Z _a and Z _b are both complex numbers including imaginary numbers. Therefore, by replacing Z _b with jK, the input impedance in the case of Z ₁₃ = 0 can be expressed as an imaginary part and an imaginary part, as shown in the following equation (28).

&Quot; (28) "

Here, in order for the double-sided LCC converter 1000 according to the embodiment of the present invention to perform the constant-voltage charging of the battery under the zero phase angle (ZPA) condition, the imaginary part of the input impedance disclosed in equation (28) can confirm. That is, when K in Equation (28), that is, Z _b is 0, the double-sided LCC converter 1000 according to an embodiment of the present invention can achieve the zero phase angle (ZPA) condition at the resonant frequency. However, when Z _b becomes zero, the power can not be delivered to the load.

As described above, the double-sided LCC converter 1000 according to an embodiment of the present invention must satisfy Equation 25 or 26 in order to perform the constant-voltage charging. When the double-sided LCC converter 1000 is implemented to satisfy the condition disclosed in Equation 25, ZPA) conditions can not be achieved. On the other hand, when the double-sided LCC converter 1000 according to an embodiment of the present invention is Z ₁₃ = -2Z _a in FIG. 5B according to Equation 26, FIG. 5B can be redrawn as shown in FIG. In such a case, the input impedance can be expressed by the following equation (29).

&Quot; (29) "

The imaginary part in Equation (29) can be expressed as Equation (30) below.

&Quot; (30) "

Here, in order for the double-sided LCC converter 1000 according to an embodiment of the present invention to perform the constant-voltage charging of the battery under the zero phase angle (ZPA) condition, the imaginary part of the input impedance disclosed in Equation 30 must be zero . That is, in order for the double-sided LCC converter 1000 according to the embodiment of the present invention to perform the constant-voltage charging of the battery under the zero phase angle (ZPA) condition, A ₁ and A ₂ become 0 at the resonance angular frequency of the CV mode It should be implemented so as to satisfy the following expression (31).

&Quot; (31) "

As described above, in order for the double-sided LCC converter 1000 according to the embodiment of the present invention to perform the constant-voltage charging of the battery under the zero phase angle (ZPA) condition, it must be implemented to satisfy the above-described equations (26) and (31).

Hereinafter, a method of implementing the double-sided LCC converter 1000 according to an embodiment of the present invention will be described with reference to FIG.

8 is a flowchart illustrating a method of implementing a two-sided LCC converter according to an embodiment of the present invention.

The two-sided LCC converter 1000 according to an exemplary embodiment of the present invention is a converter for a battery charger that supports wireless charging. The converter 200 converts an input voltage V _in to an inductive power transmission method to generate an output load R _o , It is possible to realize the constant current / constant voltage charging of the battery under the zero phase angle (ZPA) condition. To this end, the double-sided LCC converter 1000 according to an embodiment of the present invention includes a full bridge inverter 110 connected to an input terminal, a load network 140 connected to an output load R _o , a full bridge inverter 110 And an LCC resonant tank 120 for performing voltage conversion between the load network 140 and the load network 140. At this time, a rectifying bridge 130 may be provided between the LCC resonant tank 120 and the load network 140. Here, the LCC resonance tank 120 may have a resonance inductor and a resonance tank composed of two resonance capacitors provided on both sides of the primary side and the secondary side, respectively. The double-sided LCC converter 1000 according to the embodiment of the present invention can perform the constant current and the constant voltage charging under the zero phase angle (ZPA) condition by the LCC resonance tank 120, The method of implementing the LCC resonance tank 120 will be described below.

Referring to FIG. 8, the constant current mode frequency f _CC may be selected 800 considering the size and loss of the resonant elements included in the LCC resonant tank 120. In general, the switching frequency of the converter for wireless charger is selected between 20 kHz and 95 kHz, and the constant current mode frequency (f _CC ) will be described below as 68 kHz.

The mutual inductance M of the primary coil 124 and the secondary coil 125, the primary side and the secondary side of the secondary coil 125 are determined based on the limitation of the size and the weight of the coil, And the secondary side self inductance (L ₁ , L ₂ ) can be set (810).

The inductance L _1p of the primary side resonance inductor 121 and the inductance L _1s of the secondary side resonance inductor 128 can be set 820. The inductance L _1p of the primary side resonance inductor 121 and the inductance L _1s of the secondary side resonance inductor 128 can be calculated according to Equation (11) on the assumption that the two values are the same. The inductance L _1p of the primary side resonance inductor 121 and the inductance L _1s of the secondary side resonance inductor 128 are determined by the mutual inductance of the primary side coil 124 and the secondary side coil 125 M), primary and secondary side inductances (L ₁ , L ₂ ), input voltage, output current, and constant current mode frequency.

The capacitance C _{2p of the} second primary-side resonant capacitor 123 and the capacitance C _2s of the second secondary-side resonant capacitor 127 can be set (830). The capacitance C _{2p of the} second primary resonant capacitor 123 and the capacitance C _2s of the second secondary resonant capacitor 127 can be calculated by the equations 12 and 18, respectively. According to Equations 12 and 18, the capacitance C _{2p of the} second primary-side resonant capacitor 123 and the capacitance C _2s of the second secondary-side resonant capacitor 127 are equal to the inductance of the primary-side resonant inductor 121, (L _1p ) and the inductance (L _1s ) of the secondary resonance inductor 128 and the constant current mode frequency.

The capacitance C _1p of the first primary resonant capacitor 122 and the capacitance C _1s of the first secondary resonant capacitor 126 can be set 840. The capacitance C _1P of the first primary resonant capacitor 122 and the capacitance C _1s of the first secondary-side resonant capacitor 126 can be calculated by the above-described expression (20).

When the LCC resonance tank 120 is implemented by a value calculated through such a step, the double-sided LCC converter 1000 according to the embodiment of the present invention can perform the constant current charging under the zero phase angle (ZPA) condition .

Here, the double-sided LCC converter 1000 according to an embodiment of the present invention may be configured so that the LCC resonance tank 120, which is calculated in the above-described steps, can perform not only constant current charging under the zero phase angle (ZPA) Parameters can be verified. That is, it can be checked whether the parameters of the LCC resonance tank 120 satisfy the constant voltage charging condition under the zero phase angle (ZPA) condition (850). At this time, it is possible to confirm whether or not the parameters of the LCC resonance tank 120 satisfy Equations 26 and 31. As a result, when the equations (26) and (31) are satisfied, the LCC resonance tank 120 The resonance tank 120 may be implemented 860 and vice versa, the mutual inductance M of the primary coil 124 and the secondary coil 125 and the primary and secondary inductances L ₁ and L ₂ (810).

The method of implementing the double-sided LCC converter 1000 according to an embodiment of the present invention includes setting the parameters of the LCC resonant tank 120 so as to realize the constant current and the constant voltage charging under the zero phase angle (ZPA) condition The primary side of the LCC resonance tank 120 is connected to the full bridge inverter 110 for transmitting the input power and the secondary side of the LCC resonance tank 120 is connected to the rectifier bridge 120. [ (130) and the load network (140). Accordingly, the double-sided LCC converter 1000 according to an embodiment of the present invention can perform voltage conversion of the inductive power transfer system between the primary side and the secondary side of the LCC resonance tank 120, When the battery pack is operated in the constant current mode for constant voltage charging, the battery pack is operated under the fixed frequency condition when the battery pack is operated in the constant voltage mode for constant voltage charging.

Hereinafter, according to a method of implementing the double-sided LCC converter 1000 according to an embodiment of the present invention, it is verified whether constant current / constant voltage charging is possible under the zero phase angle (ZPA) condition.

9A and 9B are views illustrating an example of measuring transconductance gain and voltage gain according to the input impedance of the double-sided LCC converter according to an embodiment of the present invention.

First, a double-sided LCC converter 1000 according to an embodiment of the present invention is applied to a wireless charger having the condition shown in Table 2 below. The two-sided LCC converter 1000 is implemented by calculating the parameters and the transconductance gain according to the input impedance Z _in is measured. The graph shown in FIG. 9A is calculated. The voltage gain according to the input impedance Z _in is measured The graph as shown in FIG. 9B was calculated.

P _o Power rating 6.6 [kW] V _in Input voltage 400 [DC] V _o Output voltage 250-420 [V] I _o Charge current 15.7 [A]

9A, when the double-sided LCC converter 1000 according to an exemplary embodiment of the present invention operates at a constant current mode frequency f _cc (68 kHz), the transconductance gain G _I is a function of the load resistance R _o It can be confirmed that the zero phase angle (ZPA) condition is achieved.

9B, when the double-sided LCC converter 1000 according to an embodiment of the present invention operates at a constant voltage mode frequency f _CV (79.1 kHz), the voltage gain is proportional to the magnitude of the load resistance R _o And it can be confirmed that the zero phase angle (ZPA) condition is achieved at this time.

Hereinafter, with reference to FIGS. 10 and 11, a description will be given of considerations in implementing the double-sided LCC converter 1000 according to an embodiment of the present invention.

FIG. 10 is a view showing an example of a battery charging profile and equivalent impedance of a battery of a double-sided LCC converter according to an embodiment of the present invention. Fig. 2 is a view showing an example of a transmission pad.

The double-sided LCC converter 1000 according to an embodiment of the present invention includes radio coils and an LCC resonance tank 120 to realize constant current / constant voltage charging of the battery connected to the output stage as shown in FIG. have.

In the double-sided LCC converter 1000 according to an embodiment of the present invention, the inductive power transfer pad plays an important role, and the overall efficiency is determined by the coupling factor k and the quality factor of the coil Because. In general, the coupling coefficient k can be determined by the ratio between the pad area and the air gap, the number of turns, and the number of ferrite bars. Thus, the inductive power transfer pad is preferably designed to have a high coupling coefficient (k) and a cue factor of minimum volume and weight. For example, the DD type inductive power transfer pad as shown in Fig. 11 can satisfy this condition, and also has the highest basic flux path length, and is resistant to horizontal misalignment.

Meanwhile, when the double-sided LCC converter 1000 according to the embodiment of the present invention performs the constant current charging with the charging current of 15.A, the size of the resonant inductors of the LCC resonant tank 120 is expressed by the following equation Can be calculated as shown in Equation (32).

(32)

It is preferable that the air core is used as the resonant inductor of the LCC resonant tank 120 because the resonant inductors of the LCC resonant tank 120 are subjected to a considerably high voltage by the resonance. Otherwise, the size of the resonant inductor of the LCC resonant tank 120 can be extremely large.

Hereinafter, the advantageous effects of the double-sided LCC converter 1000 according to an embodiment of the present invention will be verified with reference to FIGS. 12A to 15. FIG.

12A to 15 illustrate advantageous effects of the double-sided LCC converter 1000 according to an embodiment of the present invention.

12A and 12B are diagrams showing two examples of waveforms when the double-sided LCC converter 1000 according to an embodiment of the present invention operates in a constant current mode for performing constant current charging. In this case, Was set to 400V.

Referring to FIG. 12A, it can be seen that, when operating at a constant current mode frequency of 67.5 kHz, the output power is 3.9 kW and the output current I ₀ is constant at 15.7 A. Referring to FIG. 12 b, when operating in the frequency, the output power can be confirmed that the schedule to 6.6kW, the output current (I _o) is 15.7A.

12A and 12B, it can be seen that the ZVS and ZCS conditions of the switching elements can be achieved in both cases when operating at a constant current mode frequency, This is because the double-sided LCC converter 1000 according to the embodiment performs the constant current charging under the zero phase angle (ZPA) condition.

12A and 12B, as the output power increases (3.9 kW-> 6.6 kW), the operating frequency slightly changes in order to keep the output current I ₀ constant. This change is caused by the FHA and the resonance elements Side LCC converter 1000 according to an exemplary embodiment of the present invention due to the left-side resistance thereof. However, this problem can be easily solved by applying a closed loop of simple PI control. As a result, the double-sided LCC converter 1000 according to an embodiment of the present invention can operate under a fixed frequency condition when operating in a constant current mode for constant current charging.

FIGS. 13A and 13B illustrate two examples of waveforms when a double-sided LCC converter 1000 according to an embodiment of the present invention is operated in a constant voltage mode for performing constant-voltage charging. In this case, Respectively.

Referring to FIG. 13A, it can be seen that, when operating at a constant voltage mode frequency of 77.5 kHz, the output power is 5.88 kW and the output voltage (V _o ) is constant at 420 V. Referring to FIG. 13B, , It can be confirmed that the output power is 2.52 kW and the output voltage (V _o ) is constant at 420 V.

13A and 13B, it can be seen that, in both cases, only the ZVS condition of the switching elements can be achieved when operating at the constant voltage mode frequency. This is because the double-sided LCC converter according to the embodiment of the present invention (1000) operates under frequency conditions below the resonant frequency (77 kHz) to obtain a higher voltage gain, operating in an inductive region.

14A and 14B, it can be seen that when operating at constant voltage mode frequencies of 78.6 kHz and 79.4 kHz, the switch elements can achieve both zero voltage switching (ZVS) and zero current switching (ZCS) conditions . As described above, the double-sided LCC converter 1000 according to an exemplary embodiment of the present invention can operate under a fixed frequency condition when operating in a constant voltage mode for constant voltage charging. As a result, by adjusting the constant voltage mode frequency, Voltage switching (ZVS) and zero current switching (ZCS) conditions.

As described above, the most significant advantage of the double-sided LCC converter 1000 according to the embodiment of the present invention is that the constant current and the constant voltage charging can be performed under the fixed frequency condition regardless of the change in the load, can do.

Referring to FIG. 15, the efficiency of the double-sided LCC converter 1000 according to an embodiment of the present invention under different output conditions can be confirmed. 15, it can be seen that the double-sided LCC converter 1000 according to an embodiment of the present invention has a maximum efficiency of 96.1% at an output power of 6.6 kW when operated in the constant current mode. In addition, the double-sided LCC converter 1000 according to an exemplary embodiment of the present invention exhibits better efficiency when the input voltage is 420 V in the constant voltage mode than when the input voltage is 400 V, ZPA) conditions.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

1000: Double-sided LCC converter 121: Primary side resonant inductor
110: full bridge inverter 122: first primary resonant capacitor
120: LCC resonant tank 123: second primary resonant capacitor
130: rectifier bridge 124: primary coil
140: load network 125: secondary coil
126: first secondary resonance capacitor
127: second secondary resonance capacitor
128: secondary resonant inductor

Claims (15)

A full bridge inverter connected to an input power source for supplying an input voltage and having first to fourth switches;
Wherein the primary resonance tank is connected to the full bridge inverter and receives the input voltage, the primary side resonance tank is connected to the full bridge inverter, and the primary side resonance tank is connected to the full- An LCC resonance tank for performing voltage conversion of an inductive power transmission system between the resonance tank and the secondary resonance tank;
A rectifying bridge connected to the secondary resonance tank for rectifying an output voltage received from the secondary resonance tank; And
And a load network coupled to the rectifying bridge for receiving a rectified output voltage. The method according to claim 1,
In the LCC resonance tank,
A first primary resonant capacitor and a second primary resonant capacitor; a first primary resonant inductor connected to the full bridge inverter; a first primary resonant capacitor and a second primary resonant capacitor connected to the primary resonant inductor; Side resonance capacitor and a second secondary resonance capacitor connected to the secondary-side resonance inductor, a second secondary-side resonance capacitor connected to the secondary-side resonance inductor, a second secondary-side resonance capacitor connected to the secondary-side resonance inductor, Side resonant capacitor, and a secondary-side resonant tank composed of a secondary-side coil connected to the second secondary-side resonant capacitor. 3. The method of claim 2,
Wherein the self inductance of the primary coil and the secondary coil is set to be the same. The method according to claim 1,
In the LCC resonance tank,
Sided LCC converter for a wireless charger that outputs a constant magnitude current regardless of changes in the load network when operating under constant current mode frequency conditions of fixed frequency. 5. The method of claim 4,
In the LCC resonance tank,
Side LCC for a wireless charger that achieves the zero phase angle condition of the input impedance and performs the switching operation under the soft switching condition when the first switch and the fourth switch provided in the full bridge inverter are operated under the constant current mode frequency condition, Converter. The method according to claim 1,
In the LCC resonance tank,
Sided LCC converter for a wireless charger that outputs a constant magnitude of voltage regardless of the change in the load network when operating under a constant frequency frequency condition. The method according to claim 6,
In the LCC resonance tank,
Way LCC for a wireless charger in which the first switch to the fourth switch provided in the full bridge inverter performs a switching operation under soft switching conditions when operating under the constant voltage mode frequency condition, Converter. And an LCC resonance tank configured to perform voltage conversion of the induction power transfer system between the resonance tank of the primary side and the resonance tank of the primary side including the primary side coil and the secondary side coil, respectively, constituted by one resonance inductor and two resonance capacitors Side LCC resonant converter for a wireless charger that transmits a voltage of an input terminal connected to the primary resonance tank to an output terminal connected to the secondary resonance tank,
A constant current mode frequency which is an operating frequency in a constant current mode for outputting a constant current to the output terminal in consideration of the size and loss of the resonant elements included in the LCC resonant tank,
The mutual inductance of the primary coil and the secondary coil, the self-inductance of each of the primary coil and the secondary coil is set according to the size and weight of the primary coil and the secondary coil,
And the output currents of the primary coil and the secondary coil, the inductance of each of the primary coil and the secondary coil, the constant current mode frequency, the input voltage supplied from the input terminal, Calculates an inductance or a capacitance of the resonant elements included in the LCC resonant tank,
According to the inductance or the capacitance of the resonance elements included in the LCC resonance tank, the input impedance of the LCC resonance tank is set to be in the constant voltage mode for operating the constant voltage mode for outputting a constant voltage to the output terminal. Resonance tank according to the self inductance of each of the primary coil and the secondary coil and the inductance or capacitance of the resonance elements included in the LCC resonance tank according to the result of the verification Lt; RTI ID = 0.0 > LCC < / RTI > resonant converter for a wireless charger. 9. The method of claim 8,
Wherein the primary side resonance tank further comprises a first bridge to a fourth bridge, and the first side resonance tank is connected to a full bridge inverter that is provided at the input end and includes the first to fourth switches to transfer the input voltage to the LCC resonance tank. / RTI > 10. The method of claim 9,
Wherein the secondary side resonance tank further comprises a first diode to a fourth diode and is connected to a rectifying bridge for rectifying the output of the LCC resonance tank. . 9. The method of claim 8,
Setting the mutual inductance of the primary coil and the secondary coil, and the self inductance of each of the primary coil and the secondary coil according to the size and weight of the primary coil and the secondary coil,
Wherein the self-inductance of each of the primary coil and the secondary coil is set to have the same value. 9. The method of claim 8,
And the output currents of the primary coil and the secondary coil, the inductance of each of the primary coil and the secondary coil, the constant current mode frequency, the input voltage supplied from the input terminal, The calculation of the inductance or the capacitance of the resonance elements included in the LCC resonance tank,
Wherein the inductance or capacitance of the resonant elements included in the LCC resonant tank is calculated so as to satisfy the zero phase angle condition of the input impedance of the LCC resonant tank under the constant current mode frequency condition. Way. 9. The method of claim 8,
Setting a constant current mode frequency which is an operation frequency in a constant current mode for outputting a constant magnitude current to the output terminal in consideration of size and loss of resonant elements included in the LCC resonant tank,
And setting the constant current mode frequency to be a fixed frequency. 9. The method of claim 8,
According to the inductance or the capacitance of the resonance elements included in the LCC resonance tank, the input impedance of the LCC resonance tank is set to be in the constant voltage mode for operating the constant voltage mode for outputting a constant voltage to the output terminal. To verify whether the phase angle condition is satisfied,
And verifies whether the zero phase angle condition of the input impedance of the LCC resonance tank is satisfied under the constant voltage mode frequency condition that is a fixed frequency. 9. The method of claim 8,
According to the verification result, implementing the LCC resonance tank according to the self inductance of each of the primary side coil and the secondary side coil, and the inductance or capacitance of the resonance elements included in the LCC resonance tank,
When the inductance or capacitance of the resonance elements included in the LCC resonance tank calculated as a result of the verification satisfies the zero phase angle condition of the input impedance of the LCC resonance tank under the constant voltage mode frequency condition, The inductance or the capacitance of the resonant elements included in the LCC resonant tank is equal to or greater than the inductance or capacitance of the resonant elements included in the LCC resonant tank, The mutual inductance of the primary coil and the secondary coil, and the inductance of the primary coil and the secondary coil, depending on the size and weight of the primary coil and the secondary coil, until the zero phase angle condition of the input impedance of the LCC resonant tank is satisfied. Side coils and the secondary coils themselves Lt; RTI ID = 0.0 > LCC < / RTI > resonant converter for a wireless charger comprising repeating the step of setting the inductance.

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