CN117220519B - Design method and simulation device of half-bridge series resonance LLC circuit - Google Patents
Design method and simulation device of half-bridge series resonance LLC circuit Download PDFInfo
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Abstract
The application belongs to the technical field of power supplies, and provides a design method and a simulation device of a half-bridge series resonance LLC circuit, wherein an input voltage range, an output voltage range and output power of the half-bridge series resonance LLC circuit are determined; setting a resonance frequency point of a half-bridge series resonance LLC circuit; calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage; and calculating the minimum equivalent resistance of the resonant circuit from the minimum secondary side output resistance of the transformer to the primary side, calculating the device parameters of the half-bridge series resonant LLC circuit according to the design parameter expression, generating a gain curve according to the gain function, limiting the gain curve in the gain range, and adjusting until the device parameters of the half-bridge series resonant LLC circuit are all located in the corresponding parameter range, thereby improving the design efficiency and project research and development efficiency of the half-bridge series resonant LLC circuit.
Description
Technical Field
The application belongs to the technical field of power supplies, and particularly relates to a design method and a simulation device of a half-bridge series resonance LLC circuit.
Background
The LLC circuit is mainly divided into a half-bridge LLC circuit and a full-bridge LLC circuit, wherein the full-bridge is an H-bridge and is provided with 4 switching tubes, the half-bridge is only half of the H-bridge, and only 2 switching tubes are provided. The half-bridge LLC circuit can output medium and low voltages and is suitable for occasions with low voltage output. The traditional LLC circuit regulates output voltage by regulating switching frequency, but the regulating range is limited, the output gain is closely related to the load, and particularly under the condition of light load output, the low-voltage output can be realized only by the very high switching frequency, but the higher switching frequency is unfavorable for the optimal design of a driving power supply and a transformer, and meanwhile, the system efficiency is reduced.
Therefore, how to design a half-bridge LLC circuit meeting the application requirements is a current urgent problem.
Disclosure of Invention
In order to solve the technical problems, the embodiments of the present application provide a design method and a simulation device for a half-bridge series resonant LLC circuit, which aims to provide a design method that can improve the design efficiency of the half-bridge series resonant LLC circuit and can meet application requirements.
A first aspect of the embodiments of the present application provides a method for designing a half-bridge series resonant LLC circuit, the half-bridge series resonant LLC circuit including: the first end of the first switch tube is connected with the positive electrode input end, the second end of the first switch tube and the first end of the second switch tube are commonly connected with the first end of the resonance capacitor, the second end of the resonance capacitor is connected with the first end of the first resonance inductor, the second end of the first resonance inductor and the first end of the second resonance inductor are commonly connected with the first input end of the transformer, the second end of the second switch tube, the second end of the second resonance inductor and the second end of the transformer are commonly connected with the negative electrode input end, the first secondary winding of the transformer is connected to the two ends of the output capacitor through the first diode, and the second secondary winding of the transformer is connected with the two ends of the output capacitor in parallel through the second diode; the design method comprises the following steps:
determining an input voltage range, an output voltage range and output power of the half-bridge series resonant LLC circuit;
setting a working resonance frequency point of the half-bridge series resonance LLC circuit;
calculating a turn ratio of the transformer and a gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage;
calculating the minimum equivalent resistance Rac_min=n on the resonant circuit converted from the minimum secondary side output resistance of the transformer to the primary side 2 *8*Ro_min/（π 2 ) The method comprises the steps of carrying out a first treatment on the surface of the Where ro_min=vo 2 /(1.5×po), ro_min is the minimum secondary side output resistance of the transformer, po is the output power, and Vo is the output voltage;
calculating device parameters of the half-bridge series resonant LLC circuit according to a design parameter expression, wherein the design parameter expression comprises:
maximum value of quality factor；
Minimum resonant frequency；
Maximum resonant frequency；
The resonant capacitor；
The first resonant inductor；
K=Lm/Ls，Lm is the excitation inductance of the transformer, and Gmax and Gmin are the maximum gain and the minimum gain of the half-bridge series resonance LLC circuit, respectively;
generating a gain curve according to the gain function, and limiting the gain curve in the gain range for adjustment until the device parameters of the half-bridge series resonance LLC circuit are all in the corresponding parameter range; wherein the gain function is:
fr is the resonance frequency point of the half-bridge series resonance LLC circuit, and Q is the quality factor.
In one embodiment, the determining the input voltage range, the output voltage range, and the output power of the half-bridge series resonant LLC circuit includes:
determining an input voltage range, an output voltage range and output power of the half-bridge series resonant LLC circuit according to a preset relation; the preset relation comprises:
Vin_dc_min=Vin_ac_min*1.2；
Vin_dc_max=Vin_ac_max*1.4；
Vin_dc_nor=Vin_ac_nor*1.4；
Io_max=Io*1.5；
Po=（Vo+Vd）*Io；
Po_max=（Vo+Vd）*Io_max；
wherein vin_dc_min is the lowest dc input voltage, vin_ac_min is the lowest ac input voltage,
vin_dc_max is the highest dc input voltage, vin_ac_max is the highest ac input voltage, vin_dc_nor is the rated dc input voltage, vin_ac_nor is the rated ac input voltage, vo is the output voltage, io is the output current, io_max is the maximum output current, vd is the first diode drop, po is the output power, and po_max is the maximum output power.
In one embodiment, the calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage includes:
the turn ratio n= (vin_dc_nor/2)/(vo+vd) of the transformer is calculated.
In one embodiment, the calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage includes:
calculating a minimum gain gmin= 2*n (vo+vd)/vin_dc_max of the half-bridge series resonant LLC circuit;
calculating the maximum gain gmax= 2*n (vo+vd)/vin_dc_min of the half-bridge series resonant LLC circuit;
the gain midpoint gnor= 2*n (vo+vd)/vin_dc_nor of the half-bridge series resonant LLC circuit is calculated.
In one embodiment, the resonant capacitor, the first resonant inductor and the second resonant inductor form a resonant cavity; the design method further comprises the following steps:
setting a pure resistive condition that the resonant cavity is pure resistive, wherein the pure resistive condition is as follows:
the method comprises the steps of carrying out a first treatment on the surface of the Where k=lp/Ls, lp is the inductance value of the second resonant inductor.
In one embodiment, the design method further comprises:
setting the requirements of the half-bridge series resonant LLC circuit for realizing ZVS, wherein the requirements comprise:
ilm_min > Ip; ilm_min, ip are respectively the minimum current flowing through the transformer and the current flowing through the second resonant inductor, ilm_min=vin_dc_max/(4×fmax×lm), ip= (2×coss+cstray) ×vin_dc_max/Td, cstray is the parasitic capacitance of the half bridge midpoint to ground, coss is the source-drain capacitance of the first switching tube, and Td is the dead time between the first switching tube and the second switching tube.
In one embodiment, the design method further comprises:
calculating an effective current value of a resonant cavity of a primary side of the transformer;
setting parameters of the first switching tube and the second switching tube according to the effective current value; wherein the expression of the effective current value includes:
；
；
irms_mos is the effective current flowing through either the first switching tube or the second switching tube.
In one embodiment, the design method further comprises:
calculating the switching tube loss of the primary side of the transformer and the diode loss of the secondary side of the transformer according to the effective current value;
and adjusting the output power according to the switching tube loss and the diode loss.
In one embodiment, the calculating the switching tube loss of the primary side of the transformer and the diode loss of the secondary side of the transformer according to the effective current value includes:
the expression of the switching tube loss is Pconnect_loss=Irms_mos 2 *Rds_on；
The expression of the diode loss is pd_loss=vd×io.
In an embodiment, the simulation device is adapted to perform the design method as claimed in any one of claims 1-9.
The beneficial effects of the embodiment of the application are that: firstly, determining an input voltage range, an output voltage range and output power of a half-bridge series resonance LLC circuit; setting a resonance frequency point of a half-bridge series resonance LLC circuit; calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage; and calculating the minimum equivalent resistance of the resonant circuit from the minimum secondary side output resistance of the transformer to the primary side, calculating the device parameters of the half-bridge series resonant LLC circuit according to the design parameter expression, generating a gain curve according to the gain function, limiting the gain curve in the gain range, and adjusting until the device parameters of the half-bridge series resonant LLC circuit are all located in the corresponding parameter range, thereby improving the design efficiency and project research and development efficiency of the half-bridge series resonant LLC circuit.
Drawings
FIG. 1 is a schematic diagram I of a design method of a half-bridge series resonant LLC circuit provided in an embodiment of the present application;
FIG. 2 is a schematic diagram of a half-bridge series resonant LLC circuit provided by an embodiment of the present application;
FIG. 3 is a schematic diagram II of a design method of a half-bridge series resonant LLC circuit according to an embodiment of the present application;
fig. 4 is a schematic diagram III of a design method of a half-bridge series resonant LLC circuit provided in an embodiment of the present application;
FIG. 5 is a schematic diagram IV of a design method of a half-bridge series resonant LLC circuit provided by an embodiment of the present application;
fig. 6 is a schematic diagram five of a design method of a half-bridge series resonant LLC circuit provided in an embodiment of the application;
FIG. 7 is a schematic diagram of a gain curve of a resonant cavity according to an embodiment of the present application;
FIG. 8 is a schematic diagram of an operating region of a half-bridge series resonant LLC circuit provided by an embodiment of the present application;
fig. 9 is a schematic diagram of current and voltage waveforms of a half-bridge series resonant LLC circuit provided in an embodiment of the application.
Description of the embodiments
In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is one or more than one unless specifically defined otherwise.
The embodiment of the application provides a design method of a half-bridge series resonant LLC circuit, as shown in fig. 1, where the design method in this embodiment includes steps S100 to S600, and the design method in this embodiment is used for designing circuit parameters of the half-bridge series resonant LLC circuit, so that the design efficiency of the half-bridge series resonant LLC circuit can be improved, and the application development of the half-bridge series resonant LLC circuit can be accelerated.
Referring to fig. 2, the half-bridge series resonant LLC circuit includes: the first end of the first switch tube Q1 is connected with the positive electrode input end, the second end of the first switch tube Q1 and the first end of the second switch tube Q2 are commonly connected with the first end of the resonance capacitor Cr, the second end of the resonance capacitor Cr is connected with the first end of the first resonance inductor Ls, the second end of the first resonance inductor Ls and the first end of the second resonance inductor Lp are commonly connected with the first input end of the transformer T, the second end of the second switch tube Q2 and the second end of the second resonance inductor Lp are commonly connected with the negative electrode input end, the first secondary winding of the transformer T is connected with the two ends of the output capacitor Cout through the first diode D1, and the second secondary winding of the transformer T is connected with the two ends of the output capacitor Cout through the second diode D2.
In one embodiment, the first switching tube Q1 and the second switching tube Q2 are MOS tubes.
In step S100, an input voltage range, an output voltage range, and an output power of the half-bridge series resonant LLC circuit are determined.
In step S200, an operating resonance frequency point of the half-bridge series resonant LLC circuit is set.
In step S300, the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit are calculated from the input voltage and the output voltage.
In this embodiment, it is first required to determine the input voltage range, the output voltage range, and the output power of the half-bridge series resonant LLC circuit according to application requirements, set the operating resonant frequency point fr of the half-bridge series resonant LLC circuit according to application requirements, and then calculate the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage.
In some embodiments, the operating resonant frequency point fr of the half-bridge series resonant LLC circuit is the nominal input voltage, the nominal output voltage, the LLC resonant frequency point under full load, and the operating resonant frequency point fr may be set to 100KHz.
In one embodiment, in step S100, determining an input voltage range, an output voltage range, and an output power of the half-bridge series resonant LLC circuit includes: and determining the input voltage range, the output voltage range and the output power of the half-bridge series resonant LLC circuit according to a preset relation.
In this embodiment, the preset relation includes:
Vin_dc_min=Vin_ac_min*1.2；
Vin_dc_max=Vin_ac_max*1.4；
Vin_dc_nor=Vin_ac_nor*1.4；
Io_max=Io*1.5；
Po=（Vo+Vd）*Io；
Po_max=（Vo+Vd）*Io_max；Ro=Vo 2 /Po；
Rac=n 2 *8*Ro/（π 2 ）；
rac is the equivalent resistance on the resonant circuit that translates from the secondary side to the primary side of the transformer.
Ro is the rated output resistance of the secondary side of the transformer, vin_dc_min is the lowest dc input voltage, vin_ac_min is the lowest ac input voltage, vin_dc_max is the highest dc input voltage, vin_ac_max is the highest ac input voltage, vin_dc_nor is the rated dc input voltage, vin_ac_nor is the rated ac input voltage, vo is the output voltage, io is the output current, io_max is the maximum output current, vd is the first diode drop, po is the output power, po_max is the maximum output power.
In one embodiment, the design method in this embodiment is described with vin_ac_nor=220v, vin_dc_nor=vin_ac_nor=1.4=308V, vo=24V, io=1.25V, vd=0.7v as example parameters, io_max=io_1.5=1.875a, po= (vo+vd) ×io=30.875w, po_max= (vo+vd) ×io_max= 46.313W.
In one embodiment, in step S300, calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage, includes: the turn ratio n= (vin_dc_nor/2)/(vo+vd) of the transformer is calculated.
In one embodiment, the turn ratio n= 6.235 of the transformer is calculated from the example parameters described above.
In one embodiment, in step S300, calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage, includes:
calculating the minimum gain gmin= 2*n (vo+vd)/vin_dc_max of the half-bridge series resonant LLC circuit; when the half-bridge series resonant LLC circuit reaches Gmin, it is the minimum gain, and the resonant cavity has a voltage reduction characteristic.
Calculating the maximum gain gmax= 2*n (vo+vd)/vin_dc_min of the half-bridge series resonant LLC circuit;
the gain midpoint gnor= 2*n (vo+vd)/vin_dc_nor of the half-bridge series resonant LLC circuit is calculated.
When the half-bridge series resonant LLC circuit reaches Gnor, the gain is 1, and the resonant cavity does not have the characteristics of voltage reduction and voltage increase.
In one embodiment, gmin=0.909, gmax=1.296, gnor=1 is calculated from the above example parameters.
In step S400, the minimum equivalent resistance on the resonant tank of the primary side is calculated as the minimum secondary side output resistance of the transformer.
In the present embodiment, rac_min=n 2 *8*Ro_min/（π 2 ) The method comprises the steps of carrying out a first treatment on the surface of the Where ro_min=vo 2 /(1.5×po), ro_min is the minimum output resistance of the secondary side of the transformer, po is the output power, and Vo is the output voltage.
In one embodiment, ro=vo is calculated from the above example parameters 2 /Po=18.656Ω，Ro_min=Vo 2 /(1.5×po) = 12.437 Ω, ro is the rated output resistance of the secondary side of the transformer.
In one embodiment, the equivalent resistance rac=n on the resonant loop from the secondary side to the primary side is calculated according to the above example parameters 2 *8*Ro/（π 2 ）=587.832Ω。
In step S500, device parameters of the half-bridge series resonant LLC circuit are calculated in accordance with the design parameter expression.
In the present embodiment, the design parameter expression includes:
maximum value of quality factor；
Minimum resonant frequency；
Maximum resonant frequency；
The resonant capacitor；
The first resonant inductor；
K=Lm/Ls，Lm is the excitation inductance of the transformer, and Gmax and Gmin are the maximum gain and the minimum gain of the half-bridge series resonant LLC circuit, respectively.
In the present embodiment, the smaller the K value, the narrower the frequency variation range in which the same gain is obtained; the larger the K value is, the wider the frequency variation range in which the same gain is obtained, and the lower the conduction loss and the switching loss of the first switching tube Q1 and the second switching tube Q2 in the vicinity of fr are.
In some embodiments, the K value ranges from 2.5 to 6.
Based on the above example parameters, in the design method in this example, the K value takes a value of 3.
Based on the above example parameters, qmax=0.597, fmin=67.012khz, fmax=119.78 khz, cr=6.803 nf, ls=372.390 uh, lm=k×ls=1.128 mH.
In this embodiment, there is a unique Q curve corresponding to each load.
When the output tape is heavily loaded, the Q value becomes large and the gain curve becomes relatively gentle. The corresponding operating frequency point shifts left, i.e. the operating frequency becomes lower. When the output load becomes light, the Q value becomes small, the gain curve becomes relatively steep, and the corresponding operating frequency point moves right, i.e., the operating frequency becomes large.
In step S600, a gain curve is generated according to the gain function, and the gain curve is limited in the gain range and adjusted until the device parameters of the half-bridge series resonant LLC circuit are all within the corresponding parameter ranges.
In this embodiment, the gain function is:
the method comprises the steps of carrying out a first treatment on the surface of the fr is the resonance frequency point of the half-bridge series resonance LLC circuit, and Q is the quality factor.
In this embodiment, the gain function is listed, and the function is graphically displayed by Mathcad, and the general direction of the change of the function graph can be observed by adjusting any one variable in the function, so that the graph is adjusted to conform to the current application scene in the actual debugging process by the user. The value of K in the function is related to the ratio of Lm and Ls. When the secondary load changes, the switching frequency of the upper half bridge and the lower half bridge of the primary side of the transformer has a wider range, which indicates that the K value is too large, and the inductance of Lm is reduced. On the contrary, when the secondary load changes, the switching frequency of the upper half bridge and the lower half bridge of the primary side of the transformer basically does not change, which means that the K value is too small, and the inductance of Lm is increased.
In one embodiment, the resonant capacitor Cr, the first resonant inductor Ls, and the second resonant inductor Lp form a resonant cavity; referring to fig. 3, the design method in the present embodiment further includes step S710.
In step S710, a pure resistive condition is set in which the resonant cavity is pure resistive.
In this example, the pure resistive conditions are:
。
in this embodiment, k=lp/Ls, and Lp is the inductance value of the second resonant inductor. The impedance expression Zin (x, K, Q) =2×pi×fr×ls×q (x 2 *K 2 ）/（1+x 2 *K 2 *Q 2 ）+j*（x-1/x+（x*K）/（1+x 2 *K 2 *Q 2 ）]The graph of |zin (x, K,1000000 Qnor)/(2 pi fr Ls) is shown as graph 101 in fig. 7, the graph of |zin (x, K,20 Qnor) i)/(2 pi fr Ls) is shown as graph 102 in fig. 7, the graph of |zin (x, K,2 Qnor) i)/(2 pi fr pi Ls) is shown as graph 103 in fig. 7, the graph of |zin (x, K,1.5 Qnor) i)/(2 pi fr Ls) is shown as graph 104 in fig. 7, the graph of |zin (x, K,2 Qnor)/(2 pi fr Ls) is shown as a graph 105 in fig. 7, the graph of |zin (x, K,0.01 Qnor)/(2 pi fr Ls) is shown as a graph 106 in fig. 7, and the gain curve exhibits pure resistance only when the Q value satisfies the pure resistance condition, as shown in fig. 7, the intersection of the graph 101 and the abscissa 1 is shown, and the inductive reactance and the capacitive reactance in the resonant cavity cancel each other, and the pure resistance is shown in the cavity. The so-called pure resistive curve, i.e. the amplification of the resonator is 1, and the input voltage of the resonator, i.e. the midpoint of the half bridge, is not amplified or reduced after passing the resonator. The half-bridge series resonant LLC circuit operates in the purely resistive region, which is the ideal operating state, because the resistive network has the highest quality factor and the best network characteristics.
In one embodiment, in case the half-bridge series resonant LLC circuit operates in a capacitive region (ZCS region), where the current leads the voltage, ZCS (capacitive region) turn-off is easily achieved for the preceding switching tube, which region is more suitable for IGBTs.
When the half-bridge series resonant LLC circuit works in an inductive area, the voltage is advanced in advance of the current, ZVS switching-on is easy to realize for a preceding-stage switching tube, and the area is more suitable for a MOSFET (metal-oxide-semiconductor field effect transistor), because a power tube used by a half-bridge in the half-bridge series resonant LLC circuit is a MOSFET, and the primary side MOS pursued by LLC topology is required to realize ZVS, namely zero voltage switching-on. The shutdown of the LLC primary side is then a hard shutdown, which is unavoidable. Therefore, when the LLC is designed, the LLC design works in the inductive areas, namely the ZVS1 area and the ZVS2 area in fig. 8, but in the ZVS1 area, the diode on the secondary side of the transformer cannot realize ZCS, and the problem of turn-off loss exists, namely the secondary side rectifying diode has reverse recovery loss when turned off, and the problem can be improved by selecting a fast recovery diode. ZVS2 can realize ZCS of the secondary diode, and the problem of turn-off loss does not exist. Thus, overall, the higher the efficiency at the resonance point (gain of 1) is.
As can be seen from the topology of the LLC in fig. 8 and 2, the LLC resonant cavity is composed of two inductors and one capacitor, so that there are two resonance points. One resonance point is determined by Lr and Cr, and one is determined by Lr, lm, cr. When the input is unchanged, the output load is increased, the frequency is reduced, and the output load goes towards the boosting area, namely, goes towards the left of the X axis. Otherwise, if the load is lightened, when the input is unchanged, the output load is lightened, the frequency is increased, and the motor goes towards the voltage-reducing area, namely, the motor goes towards the right of the X axis.
In one embodiment, referring to fig. 4, the design method in this embodiment further includes step S720.
In step S710, a requirement for the half-bridge series resonant LLC circuit to achieve ZVS is set.
In this embodiment, the requirements for the half-bridge series resonant LLC circuit to achieve ZVS include: ilm_min > Ip; ilm_min, ip are the minimum current flowing through the transformer and the current flowing through the second resonant inductor at the same time, ilm_min=vin_dc_max/(4×fmax×lm), ip= (2×coss+cstray) ×vin_dc_max/Td, cstray is the parasitic capacitance of the half-bridge midpoint (the common point of the first switching tube Q1 and the second switching tube Q2) to the ground, and Coss is the source-drain capacitance of the first switching tube Q1.
In one specific application embodiment, cstray is an uncontrollable variable, which is a normalization of many factors. Coss is the DS capacitance of the MOS tube, and is related to the tube type. Td is dead time between the first switching tube Q1 and the second switching tube Q2, and can be adjusted through the control chip, when IL_min calculated is smaller than Ip, the power loss of the half-bridge series resonance LLC circuit can be reduced through adjusting the Q value or the Lm value, for example, trying to reduce some.
In one example design approach, to ensure that the half-bridge series resonant LLC circuit operates at ZVS, il_min > Ip is first ensured, and after Mathcad's calculation, ilm_min=vin_dc_max/(4×fmax×lm) =0.627 a, ip= (2×coss+cstray) ×vin_dc_max/td=0.352 a, cstray=200 pF, td=300 ns, coss=56 pF can be derived.
In one embodiment, referring to fig. 5, the design method in this embodiment further includes step S810 and step S820.
In step S810, calculating an effective current value of a resonant cavity of a primary side of the transformer;
in step S820, parameters of the first switching tube Q1 and the second switching tube Q2 are set according to the effective current value.
In the present embodiment, the expression of the effective current value includes:
；
；
；
irms_mos is the effective current flowing through either the first switching tube Q1 or the second switching tube Q2.
In one embodiment, based on the above example parameters, through Mathcad's calculation, it can be derived that: irms_nor=0.328 a, irms_max=0.416 a, irms_mos is the effective value of the current flowing through the MOS transistor (the first switching transistor Q1 or the second switching transistor Q2), and can be used by the user to select MOS and calculate the conduction loss thereof.
In one embodiment, referring to fig. 6, the design method in this embodiment further includes step S830 and step S840.
In step S830, the switching tube loss of the primary side of the transformer and the diode loss of the secondary side of the transformer are calculated according to the effective current value;
in step S840, the output power is adjusted according to the switching tube loss and the diode loss.
In one embodiment, in step S830, calculating a switching tube loss of a primary side of the transformer and a diode loss of a secondary side of the transformer according to the effective current value includes:
the expression of the switching tube loss is pconduct_loss=irms_mos 2 *Rds_on；
The expression of the diode loss is pd_loss=vd×io.
In one embodiment, rds_on=0.6Ω, and based on the above example parameters, the switching tube loss pconduct_loss=irms_mos 2 * rds_on=0.032W, diode loss pd_loss=0.875W.
In one embodiment, the design method in this embodiment further comprises plotting current and voltage waveforms from the current function and the voltage function.
In one embodiment, the current function comprises a resonator current Im (t) =a sin (wt- θ).
When 0.ltoreq.t < 1/(2×fr), the magnetizing inductance current Ilm (t) =vo×n×t/Lm-vo×n/(lm×4×fr) of the transformer.
When t is equal to or greater than 1/(2×fr), the magnetizing inductance current Ilm (t) = -vo×n×t/lm+3×vo×n/(lm×4×fr) of the transformer. Therefore, the current transferred to the secondary through the transformer is f (t) =im (t) -Ilm (t).
In one embodiment, the function of the input voltage includes:
Vin_mini（t）=2*Vin_dc_nor*sin（2*π*fr*t）/（250*π）；
Vcr_max（t）=Vin_dc_nor/2+*Irms_max*sin（w*t-θ-π/2）/（2π*fr*Cr）。
based on the above current and voltage functions, the current and voltage waveforms are shown in fig. 9, where the graph of the resonant cavity current Im (t) is shown as graph 201 in fig. 9, the abscissa in fig. 9 represents the time transformer, the graph of the magnetizing inductance current Ilm (t) is shown as graph 202 in fig. 9, the graph of the current f (t) passing through the transformer to the secondary is shown as graph 203 in fig. 9, the graph 204 is vin_mini (t), the graph 205 is vin_dc-nor, the graph 206 is vin_dc (t), the graph 207 is vin_dc-nor/500, and the graph 208 is vcr_max (t)/250.
The embodiment of the application also provides a simulation device of the half-bridge series resonant LLC circuit, which is used for executing the design method according to any one of the embodiments.
The beneficial effects of the embodiment of the application are that: firstly, determining an input voltage range, an output voltage range and output power of a half-bridge series resonance LLC circuit; setting a resonance frequency point of a half-bridge series resonance LLC circuit; calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage; and calculating the minimum equivalent resistance of the resonant circuit from the minimum secondary side output resistance of the transformer to the primary side, calculating the device parameters of the half-bridge series resonant LLC circuit according to the design parameter expression, generating a gain curve according to the gain function, limiting the gain curve in the gain range, and adjusting until the device parameters of the half-bridge series resonant LLC circuit are all located in the corresponding parameter range, thereby improving the design efficiency and project research and development efficiency of the half-bridge series resonant LLC circuit.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (10)
1. A method of designing a half-bridge series resonant LLC circuit, the half-bridge series resonant LLC circuit comprising: the first end of the first switch tube is connected with the positive electrode input end, the second end of the first switch tube and the first end of the second switch tube are commonly connected with the first end of the resonance capacitor, the second end of the resonance capacitor is connected with the first end of the first resonance inductor, the second end of the first resonance inductor and the first end of the second resonance inductor are commonly connected with the first input end of the transformer, the second end of the second switch tube, the second end of the second resonance inductor and the second end of the transformer are commonly connected with the negative electrode input end, the first secondary winding of the transformer is connected to the two ends of the output capacitor through the first diode, and the second secondary winding of the transformer is connected with the two ends of the output capacitor in parallel through the second diode; the design method comprises the following steps:
determining an input voltage range, an output voltage range and output power of the half-bridge series resonant LLC circuit;
setting a working resonance frequency point of the half-bridge series resonance LLC circuit;
calculating a turn ratio of the transformer and a gain range of the half-bridge series resonant LLC circuit according to the input voltage and the output voltage;
calculating the minimum equivalent resistance Rac_min=n on the resonant circuit converted from the minimum secondary side output resistance of the transformer to the primary side 2 *8*Ro_min/（π 2 ) The method comprises the steps of carrying out a first treatment on the surface of the Where ro_min=vo 2 /(1.5×po), ro_min is the minimum secondary side output resistance of the transformer, po is the output power, and Vo is the output voltage;
calculating device parameters of the half-bridge series resonant LLC circuit according to a design parameter expression, wherein the design parameter expression comprises:
maximum value of quality factor；
Minimum resonant frequency；
Maximum resonant frequency；
The resonant capacitor；
The first resonant inductor；
K=Lm/Ls，Lm is the excitation inductance of the transformer, and Gmax and Gmin are the maximum gain and the minimum gain of the half-bridge series resonance LLC circuit, respectively;
generating a gain curve according to a gain function, and limiting the gain curve in the gain range for adjustment until device parameters of the half-bridge series resonance LLC circuit are all located in corresponding parameter ranges; wherein the gain function is:
fr is the resonance frequency point of the half-bridge series resonance LLC circuit, and Q is the quality factor.
2. The method of designing a half-bridge series resonant LLC circuit of claim 1, wherein said determining an input voltage range, an output voltage range, and an output power of the half-bridge series resonant LLC circuit comprises:
determining an input voltage range, an output voltage range and output power of the half-bridge series resonant LLC circuit according to a preset relation; the preset relation comprises:
Vin_dc_min=Vin_ac_min*1.2；
Vin_dc_max=Vin_ac_max*1.4；
Vin_dc_nor=Vin_ac_nor*1.4；
Io_max=Io*1.5；
Po=（Vo+Vd）*Io；
Po_max=（Vo+Vd）*Io_max；
wherein vin_dc_min is the lowest dc input voltage, vin_ac_min is the lowest ac input voltage,
vin_dc_max is the highest dc input voltage, vin_ac_max is the highest ac input voltage, vin_dc_nor is the rated dc input voltage, vin_ac_nor is the rated ac input voltage, vo is the output voltage, io is the output current, io_max is the maximum output current, vd is the first diode drop, po is the output power, and po_max is the maximum output power.
3. The method of designing a half-bridge series resonant LLC circuit of claim 2, wherein said calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage includes:
the turn ratio n= (vin_dc_nor/2)/(vo+vd) of the transformer is calculated.
4. A method of designing a half-bridge series resonant LLC circuit as claimed in claim 3, wherein said calculating the turn ratio of the transformer and the gain range of the half-bridge series resonant LLC circuit from the input voltage and the output voltage comprises:
calculating a minimum gain gmin= 2*n (vo+vd)/vin_dc_max of the half-bridge series resonant LLC circuit;
calculating the maximum gain gmax= 2*n (vo+vd)/vin_dc_min of the half-bridge series resonant LLC circuit;
the gain midpoint gnor= 2*n (vo+vd)/vin_dc_nor of the half-bridge series resonant LLC circuit is calculated.
5. The method of designing a half-bridge series resonant LLC circuit of claim 4, wherein said resonant capacitor, said first resonant inductor, and said second resonant inductor form a resonant cavity; the design method further comprises the following steps:
setting a pure resistive condition that the resonant cavity is pure resistive, wherein the pure resistive condition is as follows:
the method comprises the steps of carrying out a first treatment on the surface of the Where k=lp/Ls, lp is the inductance value of the second resonant inductor.
6. The method of designing a half-bridge series resonant LLC circuit of claim 2, further comprising:
setting the requirements of the half-bridge series resonant LLC circuit for realizing ZVS, wherein the requirements comprise:
ilm_min > Ip; ilm_min, ip are respectively the minimum current flowing through the transformer and the current flowing through the second resonant inductor, ilm_min=vin_dc_max/(4×fmax×lm), ip= (2×coss+cstray) ×vin_dc_max/Td, cstray is the parasitic capacitance of the half bridge midpoint to ground, coss is the source-drain capacitance of the first switching tube, and Td is the dead time between the first switching tube and the second switching tube.
7. The method of designing a half-bridge series resonant LLC circuit of claim 1, further comprising:
calculating an effective current value of a resonant cavity of a primary side of the transformer;
setting parameters of the first switching tube and the second switching tube according to the effective current value; wherein the expression of the effective current value includes:
；
；
irms_mos is the effective current flowing through either the first switching tube or the second switching tube.
8. The method of designing a half-bridge series resonant LLC circuit of claim 7, further comprising:
calculating the switching tube loss of the primary side of the transformer and the diode loss of the secondary side of the transformer according to the effective current value;
and adjusting the output power according to the switching tube loss and the diode loss.
9. The method of designing a half-bridge series resonant LLC circuit of claim 8, wherein said calculating a switching tube loss of a primary side of the transformer and a diode loss of a secondary side of the transformer based on the effective current value includes:
the expression of the switching tube loss is Pconnect_loss=Irms_mos 2 *Rds_on；
The expression of the diode loss is pd_loss=vd×io.
10. Simulation device of a half-bridge series resonant LLC circuit, characterized in that the simulation device is adapted to perform a design method according to any of the claims 1-9.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230268A (en) * | 2016-08-31 | 2016-12-14 | 中天昱品科技有限公司 | A kind of crisscross parallel LLC resonance DC/DC power inverter |
| CN106329940A (en) * | 2016-11-07 | 2017-01-11 | 江南大学 | Double-transformer serial and parallel structure full-bridge LLC (logical link control) resonant converter |
| CN108494258A (en) * | 2018-03-23 | 2018-09-04 | 南京信息工程大学 | A kind of Parameters design of full-bridge LLC resonant converter |
| CN110176863A (en) * | 2019-07-01 | 2019-08-27 | 南京信息工程大学 | A kind of LLC resonant converter Parameters design |
| CN110995006A (en) * | 2019-11-28 | 2020-04-10 | 深圳第三代半导体研究院 | Design method of power electronic transformer |
| CN113659842A (en) * | 2021-08-20 | 2021-11-16 | 浙江大学 | Control method and control device of CLLC (CLLC) controller |
| CN115224740A (en) * | 2022-09-19 | 2022-10-21 | 深圳鹏城新能科技有限公司 | Inverter with split-phase and multi-mode single-phase output switching and method |
| CN115378259A (en) * | 2022-08-03 | 2022-11-22 | 国网内蒙古东部电力有限公司电力科学研究院 | Topology of passive resonant converter based on optimization parameter calculation and control method thereof |
| CN116683776A (en) * | 2023-07-19 | 2023-09-01 | 西安石油大学 | LLC converter parameter design method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10116233B2 (en) * | 2017-02-14 | 2018-10-30 | Yang Chen | Hybrid full bridge-voltage doubler rectifier and single stage LLC converter thereof |
-
2023
- 2023-11-09 CN CN202311485529.2A patent/CN117220519B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230268A (en) * | 2016-08-31 | 2016-12-14 | 中天昱品科技有限公司 | A kind of crisscross parallel LLC resonance DC/DC power inverter |
| CN106329940A (en) * | 2016-11-07 | 2017-01-11 | 江南大学 | Double-transformer serial and parallel structure full-bridge LLC (logical link control) resonant converter |
| CN108494258A (en) * | 2018-03-23 | 2018-09-04 | 南京信息工程大学 | A kind of Parameters design of full-bridge LLC resonant converter |
| CN110176863A (en) * | 2019-07-01 | 2019-08-27 | 南京信息工程大学 | A kind of LLC resonant converter Parameters design |
| CN110995006A (en) * | 2019-11-28 | 2020-04-10 | 深圳第三代半导体研究院 | Design method of power electronic transformer |
| CN113659842A (en) * | 2021-08-20 | 2021-11-16 | 浙江大学 | Control method and control device of CLLC (CLLC) controller |
| CN115378259A (en) * | 2022-08-03 | 2022-11-22 | 国网内蒙古东部电力有限公司电力科学研究院 | Topology of passive resonant converter based on optimization parameter calculation and control method thereof |
| CN115224740A (en) * | 2022-09-19 | 2022-10-21 | 深圳鹏城新能科技有限公司 | Inverter with split-phase and multi-mode single-phase output switching and method |
| CN116683776A (en) * | 2023-07-19 | 2023-09-01 | 西安石油大学 | LLC converter parameter design method |
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