CN217883233U - Three-phase frequency conversion circuit based on wireless power transmission - Google Patents
Three-phase frequency conversion circuit based on wireless power transmission Download PDFInfo
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- CN217883233U CN217883233U CN202220738733.5U CN202220738733U CN217883233U CN 217883233 U CN217883233 U CN 217883233U CN 202220738733 U CN202220738733 U CN 202220738733U CN 217883233 U CN217883233 U CN 217883233U
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Abstract
The utility model discloses a three-phase inverter circuit based on wireless power transmission, including LLC excitation source module, wireless power transmission module, the direct AC of single-phase/three-phase-AC frequency conversion module three module, wherein: the LLC excitation source module is used for primary side high-frequency driving of wireless power transmission and can adjust the output size; the wireless electric energy transmission module is used for wireless electric energy transmission and realizes the electrical isolation of the primary side and the secondary side; the single-phase/three-phase direct AC-AC module realizes single-phase AC input and three-phase AC variable frequency output through direct AC-AC variable frequency; the whole circuit can realize variable-voltage-frequency three-phase alternating current output. The utility model discloses with the soft switch circuit of excitation source and wireless power transmission module integration structure LLC, the back level adopts AC-AC transform to accomplish vary voltage frequency conversion output function, and the circuit can improve system efficiency, and the circuit is novel, succinct, reliable, practical. The utility model discloses but wide application in motor drive or other three-phase exchanges and uses.
Description
Technical Field
The utility model belongs to the technical field of the wireless power transmission technique and the power electronics technique and specifically relates to a three-phase frequency conversion circuit based on wireless power transmission is related to, and this three-phase frequency conversion circuit utilizes wireless power transmission to realize energy transfer and input/output and keeps apart, utilizes direct AC-AC to realize three-phase vary voltage frequency conversion output.
Background
The wireless electric energy transmission frequency conversion circuit can be widely applied to the fields of rail transit, electric automobiles, mining industry, intelligent home and the like. The direct AC-AC conversion can save a rectification link, reduce loss and cost, and improve system efficiency and enhance competitiveness of wireless power transmission technology if the direct AC-AC conversion circuit is used for wireless power transmission frequency conversion circuits.
Some research is carried out on a preceding-stage high-frequency excitation source, low-frequency alternating current is directly converted into a high-frequency excitation source required by a wireless power transmission system by adopting a Boost PFC rectification and DC-AC inversion composite circuit, and experiments are carried out on an SS resonant wireless power transmission system, huang Yaqi, xiaowen Xun, 'a wireless power transmission system based on a single-stage AC-AC converter', zhongshan university newspaper (natural science edition), 2019, 58 (02): 23-28. However, at present, a three-phase frequency conversion circuit based on wireless power transmission is not reported yet.
Disclosure of Invention
An object of the utility model is to provide a three-phase frequency conversion circuit based on wireless power transmission, this three-phase frequency conversion circuit can solve the problem that realizes the three-phase vary voltage frequency conversion output of direct AC-AC under the wireless power transmission technical condition to realize that three-phase vary voltage frequency conversion provides a new thinking for based on wireless power transmission.
The purpose of the utility model is realized like this:
a three-phase frequency conversion circuit based on wireless power transmission is characterized in that: the method comprises the following steps:
the LLC excitation source module is used for primary side high-frequency driving of wireless power transmission and can adjust the output size;
the wireless electric energy transmission module is used for wireless electric energy transmission and realizes the electrical isolation of the primary side and the secondary side;
the single-phase/three-phase direct AC-AC module realizes single-phase AC input and three-phase AC variable frequency output through direct AC-AC variable frequency; the whole circuit completes the transformation and frequency conversion three-phase alternating current output of wireless electric energy transmission.
The input end of the LLC excitation source module of the utility model is a direct current power supply, and the output end of the LLC excitation source module is connected with the primary side input end of the wireless electric energy transmission module; the input of the single-phase/three-phase direct AC-AC module is connected with the secondary output end of the wireless power transmission module, and the output of the single-phase/three-phase direct AC-AC module is the system output of the utility model, and the output of the variable-voltage variable-frequency three-phase AC module is supplied to the load.
The LLC excitation source module adopts an LLC full-bridge circuit, Q 1 And Q 2 Form a bridge arm, Q 3 And Q 4 Form another bridge arm, C 1 -C 4 Are respectively connected with Q 1 -Q 4 In parallel, and C 1 -C 4 Are each Q 1 -Q 4 Equivalent capacitance C of DS And sum of respective external capacitances, L r Is the sum of equivalent leakage inductance and stray inductance of the wireless power transmission module, Q 1 -Q 4 The LLC soft switch circuit is a metal-oxide semiconductor field effect transistor (MOSFET), other suitable power electronic devices can be adopted in practical application, and the LLC excitation source module combines an excitation source with wireless power transmission to form the LLC soft switch circuit.
The single-phase/three-phase direct AC-AC module adopts a three-phase full-bridge circuit topology constructed by two-way switches S1-S6, S1 and S4, S3 and S6, and S5 and S2 respectively form three bridge arms, the midpoint of S1 and S4 is A, the midpoint of S3 and S6 is B, the midpoint of S5 and S2 is C, and the points A, B and C are output ends of the single-phase/three-phase AC-AC module; the common intersection point of S1, S3 and S5 is D, the common intersection point of S2, S4 and S6 is E, and the points D and E are the input ends of the single-phase/three-phase AC-AC module. According to actual requirements, a filter circuit, such as an LC filter circuit, an LCL filter circuit or other types of filter circuits, can be additionally arranged at the ABC output end.
The utility model discloses a single-phase/direct AC-AC module of three-phase adopts the single-phase/three-phase frequency conversion scheme of single-stage direct AC-AC, and the input is single-phase high frequency input, and the output is three-phase output.
The utility model discloses a wireless power transmission module adopts series connection-parallelly connected topology, and the in-service use can be any suitable topology, specifically selects and designs according to the actual demand.
The utility model has the advantages that:
the utility model discloses with the soft switch circuit of excitation source and wireless power transmission module integration structure LLC, the back level adopts AC-AC transform to accomplish vary voltage frequency conversion output function, and the circuit can improve system efficiency, and the circuit is novel, succinct, reliable, practical.
The utility model discloses but the wide application is used in motor drive or other three-phase exchanges including transportation trade and other all kinds of industrial and mining enterprises.
Drawings
Fig. 1 is a schematic diagram of a three-phase frequency conversion circuit based on wireless power transmission according to the present invention;
FIG. 2 is a circuit topology of a single phase/three phase AC-AC module;
FIG. 3 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module when ω t ∈ (0, π/3), where: (a) Is u R A schematic diagram of the switch states of the single-phase/three-phase AC-AC module for timing (b) is u R The schematic diagram of the switch states of the single-phase/three-phase AC-AC module at negative time;
FIG. 4 is a diagram showing the switching states of the single-phase/three-phase AC-AC module when ω t is epsilon (π/3,2 π/3), in which: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the switch states of the single-phase/three-phase AC-AC module at negative time;
FIG. 5 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module when ω t epsilon (2 π/3, π), in which: (a) Is u R For timing, each switch state of the single-phase/three-phase AC-AC module is shown in (b) u R When it is negativeThe on-off state schematic diagram of the single-phase/three-phase AC-AC module;
FIG. 6 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (π,4 π/3), where: (a) Is u R For timing, each switch state of the single-phase/three-phase AC-AC module is shown in (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
FIG. 7 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (4 π/3,5 π/3), where: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
FIG. 8 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (5 π/3,2 π), where: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
FIG. 9 is a topological diagram of a single-phase/three-phase AC-AC module with an LC filter circuit;
fig. 10 is a practical circuit of a three-phase frequency conversion circuit based on wireless power transmission;
fig. 11 is a schematic diagram of a three-phase voltage waveform.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a three-phase frequency conversion circuit based on wireless power transmission according to the embodiment.
The utility model discloses a LLC excitation source module, wireless power transmission module, the direct AC of single-phase/three-phase-AC frequency conversion module three module, wherein:
the LLC excitation source module is used for primary side high-frequency driving of wireless power transmission and can adjust the output size;
the wireless electric energy transmission module is used for wireless electric energy transmission and realizes the electrical isolation of the primary side and the secondary side;
the single-phase/three-phase direct AC-AC module realizes single-phase AC input and three-phase AC variable frequency output through direct AC-AC variable frequency; the whole circuit can realize variable-voltage-frequency three-phase alternating current output.
The input end of the LLC excitation source module is a power supply, and the output end of the LLC excitation source module is connected with the primary side input end of the wireless power transmission module; the input end of the single-phase/three-phase direct AC-AC module is connected with the secondary output end of the wireless power transmission module, and the output of the single-phase/three-phase direct AC-AC module is the system output of the utility model, and the output of the variable voltage variable frequency three-phase alternating current is supplied to the load.
Fig. 2 is a main circuit topology of the single/three phase direct AC-AC module.
The single-phase/three-phase direct AC-AC module adopts a three-phase full-bridge circuit topology constructed by bidirectional switches S1-S6. The single-phase/three-phase direct AC-AC module adopts a three-phase full-bridge circuit topology constructed by two-way switches S1-S6, the three bridge arms are respectively formed by S1 and S4, S3 and S6, and S5 and S2, the midpoint of the S1 and S4 is A, the midpoint of the S3 and S6 is B, the midpoint of the S5 and S2 is C, and the points A, B and C are output ends of the single-phase/three-phase direct AC-AC module; the common intersection point of S1, S3 and S5 is D, the common intersection point of S2, S4 and S6 is E, and the points D and E are the input ends of the single-phase/three-phase AC-AC module. According to actual requirements, a filter circuit, such as an LC filter circuit, an LCL filter circuit or other types of filter circuits, can be additionally arranged at the ABC output end.
The switching states of the bidirectional switches S1-S6 under normal working conditions are shown in a table 1, wherein '0' represents off, and '0/1' represents possible on, and whether the bidirectional switches are on or not is determined according to a sine wave fitting control algorithm.
TABLE 1S 1-S6 on-off states under Normal operating conditions/case 1
The single-phase/three-phase direct AC-AC conversion sine waveform fitting is realized by controlling the two-way switches S1-S6, and the variable frequency output is realized by controlling the cycle time.
FIG. 3And the switching state of the single-phase/three-phase AC-AC module is represented as omega t epsilon (0, pi/3), wherein: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
when ω t ∈ (0, π/3), u A Is positive, u B Is negative, u C Is positive: in FIG. 3- (a), u R If the current is positive, S2, S3 and S4 are turned off, and whether S1, S5 and S6 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 3- (b), u R Is negative, when ω t ∈ (0, π/3), u A Is positive, u B Is negative, u C If the current is positive, S1, S5 and S6 are turned off, and whether S2, S3 and S4 are turned on or not is controlled according to a sine wave fitting control algorithm.
FIG. 4 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (π/3,2 π/3), where: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
u is in the form of ω t ∈ (π/3,2 π/3) A Is positive, u B Is negative, u C Is negative: in FIG. 4- (a), u R If the current is positive, S3, S4 and S5 are turned off, and whether S1, S2 and S6 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 4- (b), u R And when the voltage is negative, the S1, the S2 and the S6 are turned off, and the S3, the S4 and the S5 are turned on or not according to a sine wave fitting control algorithm.
FIG. 5 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (2 π/3, π), where: (a) Is u R For timing, each switch state of the single-phase/three-phase AC-AC module is shown in (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
u when ω t is in the form of (2 π/3, π) A Is positive, u B Is positive, u C Is negative: in FIG. 5- (a), u R If the current is positive, S4, S5 and S6 are turned off, and whether S1, S2 and S3 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 5- (b), u R And when the voltage is negative, the S1, the S2 and the S3 are switched off, and the S4, the S5 and the S6 are switched on or off according to a sine wave fitting control algorithm.
FIG. 6 shows ω t ∈And (pi, 4 pi/3) each switching state schematic diagram of the single-phase/three-phase AC-AC module, wherein: (a) Is u R For timing, each switch state of the single-phase/three-phase AC-AC module is shown in (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
u is a value of ω t ∈ (π,4 π/3) A Is negative, u B Is positive, u C Is negative: in FIG. 6- (a), u R If the current is positive, S1, S5 and S6 are turned off, and whether S2, S3 and S4 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 6- (b), u R And when the voltage is negative, the S2, the S3 and the S4 are switched off, and the S1, the S5 and the S6 are switched on or off according to a sine wave fitting control algorithm.
FIG. 7 is a schematic diagram of the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (4 π/3,5 π/3), where: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the on-off state of each single-phase/three-phase AC-AC module is negative;
at ω t ∈ (4 π/3,5 π/3), u A Is negative, u B Is positive, u C Is positive: in FIG. 7- (a), u R If the current is positive, S1, S2 and S6 are turned off, and whether S3, S4 and S5 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 7- (b), u R And when the voltage is negative, the S3, the S4 and the S5 are turned off, and the S1, the S2 and the S6 are turned on or not according to a sine wave fitting control algorithm.
FIG. 8 is a diagram showing the switching states of the single-phase/three-phase AC-AC module at ω t ∈ (5 π/3,2 π), in which: (a) Is u R A positive single-phase/three-phase AC-AC module each switch state diagram, and (b) u R The schematic diagram of the switch states of the single-phase/three-phase AC-AC module at negative time;
u when ω t is in the range of (5 π/3,2 π) A Is negative, u B Is negative, u C Is positive: in FIG. 8- (a), when u R If the current is positive, S1, S2 and S3 are turned off, and whether S4, S5 and S6 are turned on or not is controlled according to a sine wave fitting control algorithm; in FIG. 8- (b), u R And when the voltage is negative, S4, S5 and S6 are turned off, and whether S1, S2 and S3 are turned on or not is controlled according to a sine wave fitting control algorithm.
Fig. 9 is a topological diagram of a single-phase/three-phase direct AC-AC module with an LC filter circuit.
According to actual requirements, the single-phase/three-phase direct AC-AC module can be additionally provided with a filter circuit, such as an LC filter circuit, an LCL filter circuit or other types of filter circuits, at the ABC output end. Fig. 9 shows a topology of a single-phase/three-phase direct AC-AC module with an LC filter circuit, ABC is an input terminal of the filter circuit, UVW is an output terminal of the filter circuit, and L1, L2, and L3 may be independent inductors or integrated inductors according to actual requirements.
Fig. 10 is a practical circuit of a three-phase frequency conversion circuit based on wireless power transmission.
LLC excitation source module circuit adopts LLC full-bridge circuit, Q 1 And Q 2 Form a bridge arm, Q 3 And Q 4 Form another bridge arm, C 1 -C 4 Are respectively connected with Q 1 -Q 4 In parallel, and C 1 -C 4 Are respectively Q 1 -Q 4 Equivalent capacitance C of DS And sum of respective external capacitances, L r Is the sum of equivalent leakage inductance and stray inductance of the wireless power transmission module, Q 1 -Q 4 For metal-oxide-semiconductor field effect transistors, MOSFETs, other suitable power electronics devices may be used in practice, such as insulated gate bipolar transistors, IGBTs, while C 1 -C 4 Are respectively corresponding to Q 1 -Q 4 Equivalent capacitance C of CE And the sum of the external capacitors, and so on.
And the LLC excitation source module combines an excitation source with wireless power transmission to form an LLC soft switching circuit.
In practical application, the LLC excitation source module is used for primary side high-frequency driving of wireless power transmission, and the LLC excitation source module is not limited to a specific control scheme in application. The design can be performed by the professional and will not be described in detail here.
The wireless power transmission module is shown in a series-parallel topology, and the actual use can be any suitable topology, and the specific selection is according to actual requirements.
The two-way switches S1-S6 are formed by two identical metal-oxide semiconductor field effect transistors (MOSFETs) which are reversely connected in series, namely the source electrode of the upper tube is connected with the drain electrode of the lower tube, and the drain electrode of the upper tube is connected with the drain electrode of the lower tubeThe source electrode of the lower tube is a main current port, and the grid driving control of the upper tube and the grid driving control of the lower tube are separated. Taking S1 as an example, when G11 applies a driving signal, the upper tube Q is connected 11 On, current can be from Q 11 、D 12 Passing from top to bottom; when G12 applies a driving signal, the lower tube Q12 is turned on and current can flow from Q 12 、D 11 Passing from bottom to top. The control of other bidirectional switches is completely similar to that of S1, and is not described in detail. The utility model provides a bidirectional switch not only can be formed by metal-oxide semiconductor field effect transistor MOSFET reverse series, can also be formed by two reverse blocking insulated gate bipolar transistor RB-IGBT (do not have anti-parallel diode) reverse parallel, and further, can be that the electric power electronic device that can accomplish the AC switch task wantonly constitutes.
Fig. 11 is a schematic diagram of a three-phase voltage waveform.
For ease of viewing, the waveform phases of the waveforms of fig. 11 correspond to table 1, giving three-phase voltage waveforms.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (4)
1. The utility model provides a three-phase inverter circuit based on wireless power transmission which characterized in that: the system comprises an LLC excitation source module, a wireless power transmission module and a single-phase/three-phase AC-AC module, wherein the input end of the LLC excitation source module is a direct-current power supply, and the output end of the LLC excitation source module is connected with the primary side input end of the wireless power transmission module; the input end of the single-phase/three-phase direct AC-AC module is connected with the secondary output end of the wireless power transmission module, the output of the single-phase/three-phase direct AC-AC module is the output of the system, and the variable-voltage variable-frequency three-phase alternating current is output to a load.
2. The three-phase frequency conversion circuit based on wireless power transmission according to claim 1, wherein: the LLC excitation source module is used for primary side high-frequency driving of wireless power transmission and can adjust the output size;
the wireless electric energy transmission module is used for wireless electric energy transmission and realizes the electrical isolation of the primary side and the secondary side;
the single-phase/three-phase direct AC-AC module realizes single-phase AC input and three-phase AC variable frequency output through direct AC-AC variable frequency; the whole circuit completes the transformation and frequency conversion three-phase alternating current output of wireless electric energy transmission.
3. The wireless power transmission-based three-phase frequency conversion circuit according to claim 1, wherein: the LLC excitation source module adopts an LLC full-bridge circuit, Q 1 And Q 2 Form a bridge arm, Q 3 And Q 4 Form another bridge arm, C 1 -C 4 Are respectively connected with Q 1 -Q 4 In parallel, and C 1 -C 4 Are respectively Q 1 -Q 4 Equivalent capacitance C of DS And sum of respective external capacitances, L r Is the sum of equivalent leakage inductance and stray inductance of the wireless power transmission module, Q 1 -Q 4 The LLC excitation source module is a metal-oxide semiconductor field effect transistor (MOSFET) and combines an excitation source and wireless power transmission to form an LLC soft switching circuit.
4. The wireless power transmission-based three-phase frequency conversion circuit according to claim 1, wherein: the single-phase/three-phase direct AC-AC module adopts a three-phase full-bridge circuit topology constructed by two-way switches S1-S6, the three bridge arms are respectively formed by S1 and S4, S3 and S6, and S5 and S2, the midpoint of the S1 and S4 is A, the midpoint of the S3 and S6 is B, the midpoint of the S5 and S2 is C, and the points A, B and C are output ends of the single-phase/three-phase AC-AC module; the common intersection point of S1, S3 and S5 is D, the common intersection point of S2, S4 and S6 is E, and the points D and E are the input ends of the single-phase/three-phase AC-AC module.
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