CN213279492U

CN213279492U - Interleaved parallel full-bridge LLC (logical Link control) topology circuit and DC power supply

Info

Publication number: CN213279492U
Application number: CN202022269708.0U
Authority: CN
Inventors: 张家书; 焦朋朋; 冯鹏辉
Original assignee: Luoyang Grasen Power Technology Co ltd
Current assignee: Luoyang Grasen Power Technology Co ltd
Priority date: 2020-10-13
Filing date: 2020-10-13
Publication date: 2021-05-25
Anticipated expiration: 2030-10-13

Abstract

The utility model provides a crisscross parallel full-bridge LLC topological circuit and DC power, wherein, crisscross parallel full-bridge LLC topological circuit includes: a primary side resonance circuit and a secondary side rectification circuit; the primary side resonant circuit comprises a primary side resonant upper branch and a primary side resonant lower branch which is connected with the primary side resonant upper branch in series, the primary side resonant upper branch and the primary side resonant lower branch respectively comprise 4 semiconductor field effect transistors, 1 bus capacitor, 1 resonant inductor and 1 transformer, the secondary side rectifying circuit comprises a secondary side rectifying upper branch and a secondary side rectifying lower branch which is connected with the secondary side rectifying upper branch in parallel, the secondary side rectifying upper branch and the secondary side rectifying lower branch respectively comprise 2 diodes and 1 high-frequency filter capacitor, after the outputs of the secondary side rectifying upper branch and the secondary side rectifying lower branch are connected in parallel, one end of the secondary side rectifying upper branch is connected with one end of an output differential mode inductor, the other end of the secondary side rectifying upper branch is connected with an output filter capacitor, and the other end of the output filter capacitor is connected with the other end of the output differential mode.

Description

Interleaved parallel full-bridge LLC (logical Link control) topology circuit and DC power supply

Technical Field

The utility model relates to an automatically controlled technical field of new forms of energy particularly, relates to a crisscross parallel full-bridge LLC topological circuit and DC power.

Background

The existing market has a great demand on a DC-DC vehicle-mounted power supply module converting 3000W high voltage into low voltage, the power supply module needs to support 400-plus-750 VDC input and 27.5V 110A output, a more common method is to use two-stage power conversion, the first stage uses BOOST boosting for boosting wide-range input voltage to a stable voltage, and the second stage uses a DCDC topology (such as LLC, phase-shifted full bridge and the like) of isolation conversion to realize power conversion by using the stable voltage.

SUMMERY OF THE UTILITY MODEL

The utility model discloses just based on at least one of above-mentioned technical problem, provided a new crisscross parallel full-bridge LLC topological circuit and power, can realize wide voltage range input, simplified the complexity of control circuit and main circuit, reduced the device quantity, in addition because this topology is the parallelly connected form of former limit series connection secondary side, former limit MOSFET's withstand voltage lectotype is the half of the withstand voltage lectotype of traditional topology, has avoidd chooseing for use of superhigh pressure device to the cost of further reduction.

In view of this, the utility model provides a new crisscross parallel full-bridge LLC topological circuit, include: a primary side resonance circuit and a secondary side rectification circuit; wherein the primary side resonant circuit comprises a primary side resonant upper branch and a primary side resonant lower branch which is connected with the primary side resonant upper branch in series, the primary side resonance upper branch and the primary side resonance lower branch respectively comprise 4 semiconductor field effect transistors, 1 bus capacitor, 1 resonance inductor and 1 transformer, the secondary rectifying circuit comprises a secondary rectifying upper branch and a secondary rectifying lower branch connected with the secondary rectifying upper branch in parallel, the secondary side rectification upper branch and the secondary side rectification lower branch both comprise 2 diodes and 1 high-frequency filter capacitor, after the outputs of the secondary side rectification upper branch and the secondary side rectification lower branch are connected in parallel, one end of the output differential mode inductor is connected with one end of an output differential mode inductor, the other end of the output differential mode inductor is connected with an output filter capacitor, and the other end of the output filter capacitor is connected with the other end of the output differential mode inductor.

According to the utility model discloses a second aspect provides a DC power supply, include: the interleaved parallel full-bridge LLC topology circuit is described in the technical scheme.

According to the technical scheme, wide voltage range input is realized by using one-stage topology conversion, the complexity of a control circuit and a main circuit is simplified, the using amount of devices is reduced, in addition, because the topology is in a primary side series connection and secondary side parallel connection mode, the voltage-resistant selection of a primary side MOSFET is half of the voltage-resistant selection of the traditional topology, the selection of ultrahigh voltage devices is avoided, 600-plus 650V MOSFET devices can be used, and the cost is further reduced.

Drawings

Fig. 1 shows a circuit structure diagram of an interleaved parallel full bridge LLC topology circuit according to an embodiment of the present invention;

fig. 2 shows a circuit configuration diagram of a DC power supply according to an embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In this embodiment, the interleaved parallel full-bridge LLC topology circuit includes: a primary side resonance circuit and a secondary side rectification circuit; the primary side resonant circuit comprises a primary side resonant upper branch and a primary side resonant lower branch which is connected with the primary side resonant upper branch in series, the primary side resonant upper branch and the primary side resonant lower branch both comprise 4 semiconductor field effect transistors, 1 bus capacitor, 1 resonant inductor and 1 transformer, the secondary side rectifying circuit comprises a secondary side rectifying upper branch and a secondary side rectifying lower branch which are connected with the secondary side rectifying upper branch in parallel, the secondary side rectifying upper branch and the secondary side rectifying lower branch both comprise 2 diodes and 1 high-frequency filter capacitor, after the outputs of the secondary side rectifying upper branch and the secondary side rectifying lower branch are connected in parallel, one end of the secondary side rectifying upper branch is connected with one end of an output differential mode inductor, the other end of the secondary side rectifying upper branch is connected with an output filter capacitor, and the other end of the output filter capacitor is connected with the other end of the output differential mode inductor. Specifically, as shown in fig. 1, the potential numbers of 4 semiconductor field effect transistors in the upper branch of the primary resonance are HQ1, HQ2, HQ3 and HQ4, the potential number of the bus capacitor is C1, the potential number of the resonance capacitor is C3, the resonance inductor L1 and the transformer T1; the potential numbers of 4 semiconductor field effect transistors in the primary side resonance lower branch are HQ5, HQ6, HQ7 and HQ8, the potential number of a bus capacitor is C2, the potential number of a resonance capacitor is C4, a resonance inductor L2 and a transformer T2; the bit numbers of 2 diodes in the secondary side rectification upper branch circuit are D1 and D2, and the bit number of the high-frequency filter capacitor is C5; the bit numbers of 2 diodes in the secondary side rectification upper branch circuit are D3 and D4, and the bit number of the high-frequency filter capacitor is C6; the output differential mode inductor has a bit number of L3, and the output filter capacitor has a bit number of C7.

Wherein:

the circuit connection mode is as follows:

1) the bus capacitors C1 and C2 are connected in series;

2) the upper half part of the primary side resonant network is formed by HQ1, HQ2, HQ3, HQ4, C3, L1 and T1, the upper half part of the primary side resonant network is formed by HQ5, HQ6, HQ7, HQ8, C4, L2 and T2, the upper half part of the primary side resonant network is connected with C1 in parallel, the lower half part of the primary side resonant network is connected with C2 in parallel, and the upper resonant network and the lower resonant network are connected with corresponding bus capacitors in series;

3) d1, D2 and C5 form an upper half part of secondary side rectification, D3, D4 and C6 form a lower half part of secondary side rectification, and outputs of the upper rectification part and the lower rectification part are connected in parallel, which is an example, and the rectification mode is not limited here and can be any one of full-bridge rectification, full-wave synchronous rectification, full-bridge synchronous rectification and the like;

4) the outputs of the upper rectifying part and the lower rectifying part are connected in parallel, and then are connected in series with L3 and connected in parallel with C7 to form an output filtering part;

the control mode is as follows:

1) the drive of the HQ5, HQ6, HQ7 and HQ8 corresponds to the drive of the HQ1, HQ2, HQ3 and HQ4, the delay is 90 degrees, namely the phases are staggered, and in view of the fact that the upper half part of the resonance is copied to work at the lower half part of the resonance, only the phase delay is 90 degrees, only the drive control modes of the HQ1, HQ2, HQ3 and HQ4 are discussed later, and the operation modes of the HQ5, HQ6, HQ7 and HQ8 are similar;

2) HQ1 and HQ3 are used as frequency modulation tubes, the duty ratio is always 50%, the waveforms are consistent, and the phase difference is 180 degrees;

3) the HQ2 and the HQ4 are frequency-modulation wide tubes, when the resonant network works between the lowest working frequency and the highest working frequency, the duty ratio of the HQ2 and the HQ4 tubes is 50%, the waveforms are consistent, and the phase difference is 180 degrees; when the resonant network works to reach the highest working frequency, the frequencies of HQ1, HQ2, HQ3 and HQ4 are all fixed to be the highest working frequency, the duty ratios of HQ1 and HQ3 are still 50%, the waveforms are consistent, the phase difference is 180 degrees, the duty ratios of HQ2 and HQ4 pipes are adjusted according to the load condition and are changed between 10 and 50%, the waveforms of HQ2 and HQ4 are consistent, and the phase difference is 180 degrees; when the fixed frequency and the fixed width are not stable, outputting hiccup at the highest working frequency, namely intermittence;

4) HQ1 and HQ4 form a pair of tubes, HQ2 and HQ3 form a pair of tubes, HQ1 and HQ4 are in phase, and HQ2 and HQ3 are in phase.

Description of the working process:

1) as the above control method, the upper half part of the resonant network and the lower half part of the resonant network are completely consistent with the working wave (only the phase difference is 90 degrees, the output current can be staggered, and the ripple can be reduced), that is, in the working process, the energy transmission capacity of the upper half part of the resonant network and the lower half part of the resonant network is consistent, that is, the self-voltage-sharing function is provided, therefore, the upper half part of the resonant network and the lower half part of the resonant network are connected in series and applied to the DC power supply, and because the input basically has no ripple, the self-voltage-sharing of the positive bus and the negative bus can be realized, that is, the voltages of the buses C1.

2) As the working characteristics of the conventional LLC resonant network:

loading effect: the light load working frequency is higher, the power supply can work in a gap mode, the work is increased along with the load, the constant frequency and width modulation mode is realized, and the load is larger and works in a pure frequency modulation mode;

source benefit: the higher the input voltage, the higher the working frequency, and as the voltage increases, the frequency will change from pure frequency modulation to fixed frequency modulation width to gap, and the input voltage will decrease, or vice versa.

The interleaved parallel full-bridge LLC topology circuit has the advantages that:

1) the gain variation range of the interleaved full-bridge LLC topology with the primary side connected in series and the secondary side connected in parallel is 2 times that of the traditional full-bridge LLC topology, namely, the capability of adapting to the variation range of the input source voltage is doubled compared with the traditional full-bridge LLC, namely, the hardware has the working condition of wide voltage input;

2) the primary side is connected in series and the secondary side is connected in parallel with the staggered full-bridge LLC topology, the high-voltage input range can be widened by matching with a frequency modulation + fixed-frequency width modulation + intermittent drive control mode, under the condition of source high-voltage input, the gain is reduced by a fixed-frequency width modulation mode and intermittent work to adapt to high-voltage input, the capacity of adapting to high-voltage input is improved, and the purpose of adapting to wider-range voltage input work is achieved;

3) the topology + control mode is applied to the DC power supply, as shown in fig. 2, and can satisfy the condition of the input voltage range in most application development, that is, the primary circuit realizes the wide input voltage range operation;

4) the high-voltage tube voltage-resistant selection circuit has the advantages that the first-stage circuit control circuit is simple, and in addition, the series connection mode is input, so that when the high-voltage tube voltage-resistant selection circuit is applied to the high-voltage input condition, the pressure-resistant selection mode of the tube can be selected according to half of the input voltage, the use of the high-voltage tube is avoided, the cost is further reduced, and the product competitiveness is improved;

5) the primary side is connected in series with the secondary side in parallel, the wave phases of the upper and lower resonant networks of the primary side are different by 90 degrees, and the current ripple phase rectified by the secondary side is also different by 90 degrees, so that a part of ripple waves can be counteracted, and the use of a filter capacitor and an output capacitor is reduced, thereby greatly helping to reduce the capacity of the filter output capacitor of a large-current output or high-power output product, namely reducing the cost and improving the performance;

6) the method is applied to DC power supply development, and can realize the self-voltage-sharing work of the primary side bus because the upper half part of the resonant network is completely consistent with the circuit of the lower half part of the resonant network and the working wave is consistent (only the phase difference is 90 degrees);

7) compared with a heat dissipation design, the topological power device is easy to disperse, and the problems of local overheating, difficulty in processing and the like can be avoided.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An interleaved parallel full bridge LLC topology circuit, comprising:

a primary side resonance circuit and a secondary side rectification circuit;

wherein the primary side resonant circuit comprises a primary side resonant upper branch and a primary side resonant lower branch which is connected with the primary side resonant upper branch in series, the primary side resonance upper branch and the primary side resonance lower branch respectively comprise 4 semiconductor field effect transistors, 1 bus capacitor, 1 resonance inductor and 1 transformer, the secondary rectifying circuit comprises a secondary rectifying upper branch and a secondary rectifying lower branch connected with the secondary rectifying upper branch in parallel, the secondary side rectification upper branch and the secondary side rectification lower branch both comprise 2 diodes and 1 high-frequency filter capacitor, after the outputs of the secondary side rectification upper branch and the secondary side rectification lower branch are connected in parallel, one end of the output differential mode inductor is connected with one end of an output differential mode inductor, the other end of the output differential mode inductor is connected with an output filter capacitor, and the other end of the output filter capacitor is connected with the other end of the output differential mode inductor.

2. A DC power supply, comprising:

the interleaved parallel full bridge LLC topology circuit of claim 1.