Resonant Multiport Converter with Coordinated Modulation of Multiple Control Quantities

Abstract

This invention provides a resonant multiport converter with multi-control quantity coordinated modulation, characterized by: a port module for connecting to external devices, receiving voltage and current input from external devices, or outputting voltage and current to external devices; a resonant module for realizing energy transfer between two or more input / output ports; a non-resonant module for adjusting the resonant state; a sampling module for acquiring the current and voltage values ​​of N input / output ports during operation; a calculation module containing a preset control algorithm, which calculates control parameters based on the control algorithm and the current and voltage values; and a control module that generates corresponding PWM drive signals based on the control parameters, controlling the switching transistors of the corresponding resonant converter units to turn on or off, thereby adjusting the current and voltage values ​​of each input / output port. In summary, this method can improve the efficiency of the resonant multiport converter.

Description

Technical Field

[0001] This invention relates to a converter, specifically to a resonant multiport converter with multi-control quantity coordinated modulation. Background Technology

[0002] Solar and wind power, among other new energy sources, have attracted significant attention due to their large resource reserves, wide distribution, and pollution-free nature. However, new energy power generation is easily affected by environmental factors such as sunlight and temperature, leading to instability in the power generation process and potential imbalances between power supply and generation. Therefore, multi-port systems incorporating battery energy storage units are developed to achieve stable power supply and Maximum Power Point Tracking (MPPT) for new energy power generation.

[0003] Multiport converters (MPCs) are used for energy management in renewable energy power generation systems, energy storage systems, and loads. Their performance and cost are crucial factors affecting renewable energy power generation. Based on the current trends in power electronic converters towards higher frequencies, higher efficiency, higher power density, smaller size, and lower noise, designing suitable circuit topologies and control strategies to optimize the performance of MPCs has significant research and application value.

[0004] Power converters employing hard-switching technology suffer from high switching losses and significant electromagnetic interference, which limit the improvement of switching frequency and efficiency. Therefore, resonant converters, represented by LLC structures, have attracted much attention due to their excellent soft-switching characteristics.

[0005] However, existing LLC converters use frequency modulation control to regulate the output voltage. To cope with the wide voltage variation range of new energy power generation, the converter's switching frequency also varies greatly. When the switching frequency differs significantly from the resonant frequency, the effective value of the resonant current increases, leading to increased conduction losses and reduced converter efficiency. Therefore, the traditional LLC structure struggles to achieve full-voltage-range efficiency improvements in multi-port converter systems. Summary of the Invention

[0006] This invention is made to solve the above-mentioned problems, and its purpose is to provide a resonant multiport converter with multi-control quantity coordinated modulation.

[0007] This invention provides a resonant multiport converter with multi-control quantity coordinated modulation, characterized by the following features: a port module including N input / output ports for connecting to external devices, receiving voltage and current input from external devices, or outputting voltage and current to external devices; a resonant module including X resonant conversion units for energy transfer between two or more input / output ports; a non-resonant module including M non-resonant conversion units for resonant state adjustment; a sampling module for acquiring the current and voltage values ​​of the N input / output ports under operating conditions; a calculation module containing a preset control algorithm, which calculates control parameters based on the control algorithm and the current and voltage values; and a control module that generates corresponding PWM drive signals based on the control parameters, controls the switching transistors of the corresponding resonant conversion units to turn on or off, and adjusts the current and voltage values ​​of each input / output port, wherein X≥2, N≥2, and M≥0.

[0008] The resonant multiport converter with multi-control quantity coordinated modulation provided by the present invention may also have the following features: wherein the control algorithm includes table lookup method, interpolation calculation method, disturbance observation method, closed-loop control method and artificial intelligence method.

[0009] The resonant multiport converter with multi-control quantity coordinated modulation provided by this invention may also have the following feature: the number of input and output ports is three, including a photovoltaic connection port, a battery connection port, and a load connection port. The photovoltaic connection port is connected to the photovoltaic panel, the battery connection port is connected to the battery, and the load connection port is connected to the equivalent load resistance R. L Connected.

[0010] The resonant multiport converter with multi-control quantity coordinated modulation provided by this invention may also have the following feature: the resonant module includes a first resonant converter unit and a second resonant converter unit, the first resonant converter unit being an LLC main bridge arm, including an input filter capacitor C. in Primary power switch Q1, primary power switch Q2, primary winding of isolation transformer T, resonant inductor L1 and resonant capacitor C1, input filter capacitor C in One end is connected to the drain of the primary-side power switch Q1 and the positive terminal of the photovoltaic panel, respectively, and the input filter capacitor C inThe other end is connected to the source of the primary-side power switch Q2 and the negative terminal of the photovoltaic panel, respectively. The source of the primary-side power switch Q1 is connected to the drain of the primary-side power switch Q2 and one end of the resonant inductor L1, respectively. The other end of the resonant inductor L1 is connected to the same-name terminal of the primary-side winding, and the opposite-name terminal of the primary-side winding is connected to one end of the resonant capacitor C1. The other end of the resonant capacitor is connected to the source of the primary-side power switch Q2. The second resonant converter unit is a battery management half-bridge, including an auxiliary inductor L2, a linear inductor L3 of the battery management bidirectional Buck / Boost converter, a DC blocking capacitor C2, and a primary-side... The power switch Q3 and the primary-side power switch Q4 are connected to each other. One end of the linear inductor L3 is connected to the positive terminal of the battery. The other end of the linear inductor L3 is connected to the source of the primary-side power switch Q3, the drain of the primary-side power switch Q4, and one end of the DC blocking capacitor C2. The other end of the DC blocking capacitor C2 is connected to one end of the auxiliary inductor L2. The other end of the auxiliary inductor L2 is connected to the opposite terminal of the primary winding. The drain of the primary-side power switch Q3 is connected to the drain of the primary-side power switch Q1. The source of the primary-side power switch Q4 is connected to the source of the primary-side power switch Q2 and the negative terminal of the battery.

[0011] The resonant multiport converter with multi-control quantity coordinated modulation provided by this invention may also have the following features: The non-resonant module includes a first non-resonant conversion unit, which includes a secondary winding of an isolation transformer T, secondary rectifier diodes D1, D2, D3, and D4, and an output filter capacitor C0. The same-name terminals of the secondary winding are connected to the positive terminals of secondary rectifier diodes D1 and D2, respectively, and the opposite-name terminals are connected to the positive terminals of secondary rectifier diodes D3 and D4, respectively. One end of the output filter capacitor C0 is connected to the negative terminals of secondary rectifier diodes D1 and D3, and the equivalent load resistance R. L One end of the output filter capacitor C0 is connected to the positive terminal of the secondary rectifier diode D2, the positive terminal of the secondary rectifier diode D4, and the equivalent load resistance R, respectively. L The other end is connected.

[0012] The resonant multiport converter with multi-control quantity coordinated modulation provided by this invention may also have the following features: The arithmetic module includes a counting subunit, a regulation judgment subunit, an MPPT regulation parameter generation subunit, and an MEPT regulation parameter generation subunit. The counting subunit includes a counter for counting to obtain counting data. The regulation judgment subunit is used to determine whether the current operating condition is stable based on the counting data and the voltage and current values ​​of the photovoltaic connection port. If so, MEPT regulation is performed; otherwise, MPPT regulation is performed. The MPPT regulation parameter generation subunit is used for MPPT regulation, calculating the first parameter based on the voltage values ​​corresponding to the photovoltaic connection port, battery connection port, and load connection port using the disturbance observation method and voltage closed-loop control. The system uses first duty cycle data, first frequency data, and first phase data as control parameters. An MEPT control parameter generation subunit is used for MEPT control. Second frequency data and second phase data are calculated based on the voltage value at the load connection port using a disturbance observation method and voltage closed-loop control. These data are then used as control parameters. The control module includes a PWM controller, which generates PWM drive signals based on the input control parameters to control the conduction or shutdown of primary-side power switches Q1, Q2, Q3, and Q4, thereby achieving MPPT or MEPT control.

[0013] The resonant multiport converter with multi-control quantity coordinated modulation provided by the present invention may also have the following features: wherein the operation module further includes a fastest response speed subunit, the fastest response speed subunit is preset with a fastest response algorithm for adjusting the control parameters, and the control module controls the conduction or shutdown of each primary-side power switch according to the control parameters to achieve the optimal trade-off between MPPT, maximum efficiency and response speed.

[0014] The resonant multiport converter with multi-control quantity coordinated modulation provided by the present invention may also have the following features: wherein the operation module further includes an optimal power path subunit, the fastest response speed subunit is preset with an optimal power path algorithm, used to adjust the control parameters, and the control module controls the conduction or shutdown of each primary-side power switch according to the control parameters, so as to achieve the optimal trade-off between MPPT, maximum efficiency and power path.

[0015] The resonant multiport converter with multi-control quantity coordinated modulation provided by the present invention may also have the following feature: wherein the primary power switch Q1, primary power switch Q2, primary power switch Q3 and primary power switch Q4 are MOSFETs or IGBTs.

[0016] The resonant multiport converter with multi-control quantity coordinated modulation provided by the present invention may also have the following features: wherein the resonant structure of the resonant converter unit includes a half-bridge or full-bridge resonant structure, a phase-shifting resonant structure, an asymmetric half-bridge or full-bridge resonant structure, a forward resonant structure, an LLC resonant structure, an LCC resonant structure, a CL composite resonant structure, a CLCC resonant structure, a resonant converter network using a transformer, and a resonant network using a wireless charging coil.

[0017] The role and effect of invention

[0018] According to the multi-control quantity coordinated modulation resonant multiport converter of the present invention, on the one hand, the arithmetic module adjusts the state and parameters of the resonant unit by using the switching frequency, duty cycle, and phase shift value as control quantities to regulate the voltage, enabling the resonant multiport converter to achieve a wide voltage gain adjustment range within a narrow switching frequency variation range; on the other hand, because the MEPT control period is much longer than the MPPT control period, MPPT control and MEPT control are performed simultaneously by the MPPT control parameter generation subunit and the MEPT control parameter generation subunit. Through dynamic adaptive coordination among multiple control quantities, a trade-off between various losses is achieved within the full voltage variation range and the full load adjustment range, thereby obtaining higher efficiency. Therefore, the multi-control quantity coordinated modulation resonant multiport converter of the present invention can improve the efficiency of the resonant multiport converter. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the resonant multiport converter in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the working circuit principle of the resonant multiport converter in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a typical operating waveform of the resonant multiport converter in an embodiment of the present invention;

[0022] Figure 4 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 1 in an embodiment of the present invention;

[0023] Figure 5 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 2 in an embodiment of the present invention;

[0024] Figure 6 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 3 in an embodiment of the present invention;

[0025] Figure 7This is the equivalent circuit diagram of the resonant multiport converter in operating mode 4 in an embodiment of the present invention;

[0026] Figure 8 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 5 in an embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram illustrating the specific operation of the coordinated regulation of MPPT and MEPT in an embodiment of the present invention;

[0028] Figure 10 This is a schematic diagram illustrating the efficiency of each converter under different load conditions in an embodiment of the present invention. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the resonant multiport converter with multi-control quantity coordinated modulation of the present invention.

[0030] Figure 1 This is a schematic diagram of the resonant multiport converter in an embodiment of the present invention.

[0031] like Figure 1 As shown, the resonant multiport converter 100 of this embodiment includes a port module 10, a resonant module 20, a non-resonant module 30, a sampling module 40, a computation module 50, and a control module 60.

[0032] The port module 10 includes N input / output ports for connecting to external devices, receiving voltage and current input from external devices, or outputting voltage and current to external devices, where N≥2.

[0033] Figure 2 This is a schematic diagram of the working circuit principle of the resonant multiport converter in an embodiment of the present invention.

[0034] like Figure 2 As shown, there are three input / output ports: a photovoltaic connection port 101, a battery connection port 102, and a load connection port 103. The photovoltaic connection port 101 is connected to the photovoltaic panel PV, the battery connection port 102 is connected to the battery BAT, and the load connection port 103 is connected to the equivalent load resistance R. L Connected, v PV v BAT and v out The voltages are, in order: photovoltaic panel voltage, battery voltage, and output voltage.

[0035] The resonant module 20 includes X resonant conversion units for energy transfer between two or more input / output ports. The resonant structure of the resonant conversion unit includes a half-bridge or full-bridge resonant structure, a phase-shifting resonant structure, an asymmetric half-bridge or full-bridge resonant structure, a forward resonant structure, an LLC resonant structure, an LCC resonant structure, a CL composite resonant structure, a CLCC resonant structure, a resonant conversion network using a transformer, and a resonant network using a wireless charging coil.

[0036] Where X≥2, in this embodiment, there may be mutual influence between the resonant transformation units, including the reuse of resonant elements, the coupling of magnetic elements and the coupling of wireless charging coils.

[0037] The resonant module 20 includes a first resonant transformation unit 201 and a second resonant transformation unit 202.

[0038] The first resonant converter unit 201 is an LLC main bridge arm, including the input filter capacitor C. in The components include primary power switch Q1, primary power switch Q2, body diode T1, body diode T2, primary winding of isolation transformer T, resonant inductor L1, and resonant capacitor C1. In this embodiment, the turns ratio of isolation transformer T is n = N. p :N s .

[0039] Input filter capacitor C in One end is connected to the drain of the primary-side power switch Q1 and the positive terminal of the photovoltaic panel PV, respectively, and the input filter capacitor C in The other end is connected to the source of the primary power switch Q2 and the negative terminal of the photovoltaic panel PV, respectively. The source of the primary power switch Q1 is connected to the drain of the primary power switch Q2 and one end of the resonant inductor L1, respectively. The other end of the resonant inductor L1 is connected to the same-name terminal of the primary winding, and the opposite-name terminal of the primary winding is connected to one end of the resonant capacitor C1. The other end of the resonant capacitor is connected to the source of the primary power switch Q2. The negative terminal of the body diode T1 is connected to the drain of the primary power switch Q1, and the positive terminal of the body diode T1 is connected to the source of the primary power switch Q1. The negative terminal of the body diode T2 is connected to the drain of the primary power switch Q2, and the positive terminal of the body diode T2 is connected to the source of the primary power switch Q2. M i is the magnetizing inductance of the isolation transformer T. M For the magnetizing inductor L M The excitation current, v TP i is the voltage of the primary winding of isolation transformer T. L1 This is the resonant current.

[0040] The second resonant converter unit 202 is a battery management half-bridge, including an auxiliary inductor L2, a linear inductor L3 of the battery management bidirectional Buck / Boost converter, a DC blocking capacitor C2, a primary-side power switch Q3, a primary-side power switch Q4, a body diode T3, and a body diode T4.

[0041] One end of linear inductor L3 is connected to the positive terminal of battery BAT. The other end of linear inductor L3 is connected to the source of primary-side power switch Q3, the drain of primary-side power switch Q4, and one end of DC blocking capacitor C2. The other end of DC blocking capacitor C2 is connected to one end of auxiliary inductor L2. The other end of auxiliary inductor L2 is connected to the opposite terminal of the primary winding. The drain of primary-side power switch Q3 is connected to the drain of primary-side power switch Q1. The source of primary-side power switch Q4 is connected to the source of primary-side power switch Q2 and the negative terminal of battery BAT. The negative terminal of body diode T3 is connected to the drain of primary-side power switch Q3, and the positive terminal of body diode T3 is connected to the source of primary-side power switch Q3. The negative terminal of body diode T4 is connected to the drain of primary-side power switch Q4, and the positive terminal of body diode T4 is connected to the source of primary-side power switch Q4. L2 For injected current, i L3 This represents the battery current.

[0042] Among them, the primary side power switch Q1, primary side power switch Q2, primary side power switch Q3 and primary side power switch Q4 are MOSFETs or IGBTs.

[0043] The non-resonant module 30 includes M non-resonant transformation units for resonant state adjustment, where M≥0.

[0044] The non-resonant module 30 includes a first non-resonant transformation unit 301.

[0045] The first non-resonant converter unit 301 includes the secondary winding of the isolation transformer T, secondary rectifier diodes D1, D2, D3, and D4, and an output filter capacitor C0.

[0046] The same-name terminals of the secondary windings are connected to the positive terminals of secondary rectifier diodes D1 and D2, respectively, and the opposite-name terminals are connected to the positive terminals of secondary rectifier diodes D3 and D4, respectively. One end of the output filter capacitor C0 is connected to the negative terminals of secondary rectifier diodes D1 and D3, and the equivalent load resistance R, respectively. L One end of the output filter capacitor C0 is connected to the positive terminal of the secondary rectifier diode D2, the positive terminal of the secondary rectifier diode D4, and the equivalent load resistance R, respectively.L The other end is connected, i s This is the rectified current.

[0047] Figure 3 This is a schematic diagram of a typical operating waveform of the resonant multiport converter in an embodiment of the present invention.

[0048] like Figure 3 As shown, the horizontal axis represents the switching period T. s Time, v in the vertical axis GS1 v GS2 v GS3 and v GS4 The driving waveforms for primary-side power switches Q1, Q2, Q3, and Q4 are shown below. L1 i L2 and i L3 The current waveforms of resonant inductor L1, auxiliary inductor L2, and linear inductor L3 are shown below. M For the excitation current waveform of isolation transformer T, i s This is the waveform of the secondary-side rectified current. In one switching cycle T... s That is, t0-t 10 Internally, the resonant multiport converter 100 has 10 operating modes, where t0-t2 is the injected current i L2 Relative to the resonant current i L1 Phase shift time T D Then the phase shift value variable phase = T D / T s , t1-t2, t4-t5, t6-t7, t9-t 10 Dead time t when switching on the same bridge arm d .

[0049] On the one hand, the LLC operates in a symmetrical mode; on the other hand, during battery BAT discharge, the primary-side power switch Q3 can achieve ZVS soft switching, while the primary-side power switch Q4 is a hard switch. During battery BAT charging, the primary-side power switch Q4 can achieve ZVS soft switching, while the primary-side power switch Q3 is a hard switch. Other operating states are identical. Therefore, the operating mode of the first half-cycle t0-t5 is explained as follows based on the battery BAT discharge condition:

[0050] Figure 4 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 1 in an embodiment of the present invention.

[0051] like Figure 4As shown, in operating mode 1, i.e., t0-t1, during this period, primary-side power switches Q1 and Q4 are turned on, while primary-side power switches Q2 and Q3 are turned off. The LLC resonant cavity, i.e., the resonant inductor L1 and the resonant capacitor C1, begins to resonate during the positive half-cycle, and the resonant current i L1 Energy is transferred to the secondary side through the isolation transformer T, and then to the load, i.e., the equivalent load resistance R, via the secondary side rectifier diodes D1 and D4. L During this process, the voltage V TP =V o ·N p / N s Battery current i L3 The charging and discharging of battery BAT is achieved through freewheeling via the primary-side power switch Q4. Operating mode 1 starts at time t0 and ends when the primary-side power switch Q4 is turned off at time t1.

[0052] Figure 5 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 2 in an embodiment of the present invention.

[0053] like Figure 5 As shown, in operating mode 2, i.e., t1-t2, during this period, primary-side power switch Q1 is turned on, while primary-side power switches Q2, Q3, and Q4 are turned off. The resonant inductor L1 and resonant capacitor C1 continue to resonate, and the battery current i... L3 The current begins to decrease linearly and freewheels through the body diode T3, thereby achieving ZVS conduction of the primary-side power switch Q3.

[0054] Figure 6 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 3 in an embodiment of the present invention.

[0055] like Figure 6 As shown, in operating mode 3, i.e., t2-t3, during this period, primary-side power switches Q1 and Q3 are turned on, while primary-side power switches Q2 and Q4 are turned off, and the injected current i in the auxiliary branch... L2 The injection current increases approximately linearly, increasing the equivalent capacitance of the resonant cavity and the injected current i L2 The phase and amplitude affect the resonance time at this time. At time t3, the resonance of the positive half-cycle of LLC ends, and the working mode 3 also ends.

[0056] Figure 7 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 4 in an embodiment of the present invention.

[0057] like Figure 7 As shown, in operating mode 4, i.e., t3-t4, during this period, primary side power switches Q1 and Q3 are turned on, while primary side power switches Q2 and Q4 are turned off, and the excitation current i MRise to the resonant current i L1 Equal, magnetizing inductance L M Participating in resonance, the previous resonance ends, and the resonant current i L1 With excitation current i M As the voltage rises slowly, the isolation transformer T stops transferring energy to the secondary side, the primary and secondary sides separate, and the secondary side rectifier diodes D1, D2, D3, and D4 are all turned off. Energy flows from the output filter capacitor C0 to the equivalent load resistance R. L Provides energy.

[0058] Figure 8 This is the equivalent circuit diagram of the resonant multiport converter in operating mode 5 in an embodiment of the present invention.

[0059] like Figure 8 As shown, in operating mode 5, i.e., t4-t5, during this period, primary side power switch Q3 is turned on, while primary side power switches Q1, Q2, and Q4 are turned off. During the dead time, the excitation current i M The charge on the junction capacitance of the primary power switch Q2 is removed, and the junction capacitance of the primary power switch Q1 is charged, so that the body diode T2 conducts freewheeling, thereby creating conditions for the ZVS turn-on of the primary power switch Q2. At time t5, the primary power switch Q2 conducts with zero voltage, the resonance of the other half cycle begins, and the working mode 5 ends.

[0060] The sampling module 40 is used to collect the current and voltage values ​​of N input and output ports during operation.

[0061] The calculation module 50 contains a preset control algorithm. The control parameters are calculated based on the control algorithm and the current and voltage values. The control algorithm includes table lookup method, interpolation calculation method, disturbance observation method, closed-loop control method and artificial intelligence method.

[0062] The calculation module 50 includes a counting subunit 501, a control judgment subunit 502, an MPPT control parameter generation subunit 503, and an MEPT control parameter generation subunit 504.

[0063] The counting subunit 501 includes a counter for counting to obtain counting data.

[0064] The regulation and judgment subunit 502 is used to determine whether the current operating condition is stable based on the counting data and the voltage and current values ​​of the photovoltaic connection port. If it is stable, MEPT regulation is performed; otherwise, MPPT regulation is performed.

[0065] MPPT control parameter generation subunit 503 is used for MPPT control. It calculates the first duty cycle data, first frequency data and first phase data based on the voltage values ​​corresponding to the photovoltaic connection port, battery connection port and load connection port through the perturbation observation method and voltage closed-loop control, and uses the first duty cycle data, first frequency data and first phase data as control parameters.

[0066] The MEPT control parameter generation subunit 504 is used for MEPT control. It calculates the second frequency data and the second phase data based on the voltage value of the load connection port through the disturbance observation method and voltage closed-loop control, and uses the first duty cycle data, the second frequency data and the second phase data as control parameters.

[0067] In this embodiment, the MEPT control parameter generation subunit 504 stores a preset optimal operating point curve obtained by theoretical calculation and fitting. Based on this optimal operating point curve, the MEPT control parameter generation subunit 504 performs maximum efficiency tracking using the perturbation and observation method, calculating the overall efficiency before and after the perturbation η = 100% × (P BAT +P load ) / P PV In the formula P BAT P is the power calculated based on the voltage and current collected from the battery connection port. PV P is the power calculated based on the voltage and current collected from the photovoltaic connection port. load To determine the direction of disturbance based on the power calculated from the voltage and current collected from the load connection port, the optimal efficiency operating point under this condition is obtained. The optimal operating point curve is then corrected based on the voltage and current data at the optimal efficiency operating point. This allows the MEPT control parameter generation subunit 504 to accelerate the convergence speed of maximum efficiency tracking through the continuously corrected optimal operating point curve, i.e., to reach the optimal efficiency operating point under this condition more quickly.

[0068] Figure 9 This is a schematic diagram illustrating the specific operation of the coordinated regulation of MPPT and MEPT in an embodiment of the present invention.

[0069] like Figure 9 As shown, the control judgment subunit 502 checks at fixed intervals based on the counting data whether the voltage and current values ​​of the photovoltaic connection port fluctuate within a small range. If so, the current operating condition is stable and enters MEPT control; otherwise, the current operating condition is unstable and enters MPPT control.

[0070] In MPPT control, the MPPT control parameter generation subunit 503 sets corresponding control periods A and B for disturbance observation and voltage closed-loop control, respectively. Based on the control periods, corresponding disturbance observation or voltage closed-loop control is continuously performed until the current operating condition stabilizes. When the timer overflow flag reaches the corresponding control period, corresponding disturbance observation or voltage closed-loop control is performed. During disturbance observation, the first duty cycle data is obtained by determining the disturbance voltage using the disturbance observation method. During voltage closed-loop control, the first frequency data and first phase data that stabilize the output voltage are calculated based on the first duty cycle data.

[0071] In MEPT control, the MEPT control parameter generation subunit 504 sets corresponding control periods C and D for disturbance observation and voltage closed-loop control, respectively. Disturbance observation or voltage closed-loop control is continuously performed according to the control periods until the current operating condition becomes unstable. When the timer overflow flag reaches the corresponding control period, corresponding disturbance observation or voltage closed-loop control is performed. During disturbance observation, the second phase data is obtained by changing the phase shift value according to the disturbance observation method. During voltage closed-loop control, the second frequency data that stabilizes the output voltage is calculated based on the second phase data and the first duty cycle data.

[0072] In this embodiment, the calculation module 50 also includes a fastest response speed subunit. The fastest response speed subunit is preset with a fastest response algorithm for adjusting the control parameters. The control module controls the conduction or shutdown of each primary-side power switch according to the control parameters to achieve an optimal trade-off between MPPT, maximum efficiency and response speed.

[0073] In this embodiment, the calculation module 50 further includes an optimal power path subunit. The fastest response speed subunit is preset with an optimal power path algorithm for adjusting the control parameters. The control module controls the conduction or shutdown of each primary-side power switch according to the control parameters to achieve an optimal trade-off between MPPT, maximum efficiency, and power path.

[0074] The control module 60 generates corresponding PWM drive signals according to the control parameters, controls the switching transistors of the corresponding resonant converter units to turn on or off, and adjusts the current and voltage values ​​of each input and output port.

[0075] The control module includes a PWM controller, which generates PWM drive signals based on the input control parameters to control the primary power switches Q1, Q2, Q3 and Q4 to turn on or off, thereby achieving MPPT or MEPT control.

[0076] In this embodiment, to demonstrate the performance of the resonant multiport converter 100, the structure of this embodiment of the resonant multiport converter 100 (i.e., the cooperative control MEPT) is compared with the traditional structure of the frequency-modulated LLC three-port converter without injection current (i.e., the traditional structure of frequency-modulated control) and the structure of this embodiment of the current-injected LLC three-port converter (i.e., the fixed-frequency control) with fixed frequency, only phase-shift control and no efficiency optimization. The comparison test settings are as follows: the port voltage of the photovoltaic panel (PV) is 60V-85V, the port voltage of the battery is 48V, the port output voltage of the load is 380V, and the rated output power is 160W.

[0077] In this comparative test, the main parameters of the converter of the present invention include: switching frequency f s The frequency range is 210–300 kHz, the resonant inductance L1 is 1.6 μH, the resonant capacitor C1 is 162 nF, the auxiliary inductance L2 is 17 μH, the linear inductance L3 is 60 μH, the turns ratio n is 5:42, and the magnetizing inductance L... M It is 13uH.

[0078] Figure 10 This is a schematic diagram illustrating the efficiency of each converter under different load conditions in an embodiment of the present invention.

[0079] like Figure 10 As shown, (a), (b), (c), (d), (e), and (f) are, in order, efficiency diagrams of the converters under the following conditions: photovoltaic output of 120W to 160W, photovoltaic output of 120W to 80W, photovoltaic output of 40W to 160W, photovoltaic output of 40W to 80W, photovoltaic output of 0W to 160W, and photovoltaic output of 0W to 80W. The horizontal axis of (a), (b), (c), (d), (e), and (f) represents the photovoltaic port voltage, and the vertical axis represents the converter efficiency. It can be seen that the efficiency of the converter of the present invention is better than the two existing converters under different conditions, and the effect is particularly obvious when the photovoltaic voltage is high, with an efficiency improvement of 2%-3%. Therefore, the resonant multi-port converter 100 of this embodiment can achieve an efficiency improvement across the entire voltage range compared to existing converters.

[0080] The role and effect of the embodiments

[0081] According to the resonant multiport converter with multi-control quantity coordinated modulation involved in this embodiment, on the one hand, the arithmetic module adjusts the state and parameters of the resonant unit by using the switching frequency, duty cycle, and phase shift value as control quantities to regulate the voltage, enabling the resonant multiport converter to achieve a wide voltage gain adjustment range within a narrow switching frequency variation range. On the other hand, because the MEPT control period is much longer than the MPPT control period, MPPT control and MEPT control are performed simultaneously by the MPPT control parameter generation subunit and the MEPT control parameter generation subunit. Through dynamic adaptive coordination among multiple control quantities, a trade-off between various losses is achieved within the full voltage variation range and the full load adjustment range, thereby obtaining higher efficiency. In summary, this method can improve the efficiency of the resonant multiport converter.

[0082] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A multi-control variable coordinated modulation resonant multi-port converter, characterized in that, include: Port module, including Each input / output port is used to connect to external devices, receive voltage and current input from the external devices, or output voltage and current to the external devices. The number of input / output ports is three, including a photovoltaic connection port, a battery connection port, and a load connection port. The photovoltaic connection port is connected to the photovoltaic panel, the battery connection port is connected to the battery, and the load connection port is connected to the equivalent load resistor. Resonant module, including A resonant converter unit is used to realize energy transfer between two or more of the aforementioned input and output ports; Non-resonant modules, including One non-resonant transformation unit is used for resonant state adjustment; The sampling module is used to collect data during operation. The current and voltage values ​​of each of the input and output ports; The calculation module includes a preset control algorithm, which calculates control parameters based on the control algorithm and the current and voltage values. The calculation module includes a counting subunit, a control judgment subunit, an MPPT control parameter generation subunit, and an MEPT control parameter generation subunit. The counting subunit includes a counter for counting to obtain counting data. The control and judgment subunit is used to determine whether the current operating condition is stable based on the counting data and the voltage and current values ​​of the photovoltaic connection port. If so, MEPT control is performed; otherwise, MPPT control is performed. The MPPT control parameter generation subunit is used for MPPT control. Based on the voltage values ​​corresponding to the photovoltaic connection port, the battery connection port, and the load connection port, it calculates the first duty cycle data, the first frequency data, and the first phase data using the perturbation observation method and voltage closed-loop control. The first duty cycle data, the first frequency data, and the first phase data are then used as the control parameters. The MEPT control parameter generation subunit is used for MEPT control. Based on the voltage value of the load connection port, it calculates the second frequency data and the second phase data using the disturbance observation method and voltage closed-loop control. The first duty cycle data, the second frequency data, and the second phase data are used as the control parameters. The control module generates corresponding PWM drive signals based on the control parameters, controls the switching transistors of the corresponding resonant converter units to turn on or off, and adjusts the current and voltage values ​​at each input / output port. in, , , .

2. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 1, characterized in that: in, The control algorithms include table lookup, interpolation, disturbance observation, closed-loop control, and artificial intelligence.

3. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 1, characterized in that: in, The resonant module includes a first resonant transformation unit and a second resonant transformation unit. The first resonant converter unit is an LLC main bridge arm, including an input filter capacitor. Primary power switching transistor Primary power switching transistor Isolation transformer Primary winding, resonant inductor and resonant capacitor The input filter capacitor One end of the input filter capacitor is connected to the drain of the primary power switch Q1 and the positive terminal of the photovoltaic panel, respectively. The other end is connected to the primary power switch transistor. The source of the transistor is connected to the negative terminal of the photovoltaic panel, and the primary-side power switch transistor... The source of each is connected to the primary-side power switch. The drain and the resonant inductor One end is connected to the resonant inductor. The other end is connected to the same-name terminal of the primary winding, and the opposite-name terminal of the primary winding is connected to the resonant capacitor. One end of the resonant capacitor is connected to the resonant capacitor, and the other end of the resonant capacitor is connected to the primary-side power switch. The source poles are connected. The second resonant converter unit is a battery management half-bridge, including an auxiliary inductor. Linear inductor of bidirectional Buck / Boost converter for battery management DC blocking capacitor Primary power switching transistor and primary side power switching transistors The linear inductor One end of the linear inductor is connected to the positive terminal of the battery. The other end is connected to the primary power switch transistor. The source of the primary-side power switch The drain and the DC blocking capacitor One end is connected to the DC blocking capacitor. The other end is connected to the auxiliary inductor One end is connected to the auxiliary inductor. The other end is connected to the opposite end of the primary winding, and the primary power switch transistor The drain of the primary-side power switch transistor The drain of the primary-side power switch is connected to the primary-side power switch. The source of each is connected to the primary-side power switch. The source electrode is connected to the negative electrode of the battery.

4. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 3, characterized in that: in, The non-resonant module includes a first non-resonant transformation unit. The first non-resonant converter unit includes the isolation transformer. Secondary winding, secondary rectifier diode Secondary rectifier diodes Secondary rectifier diodes Secondary rectifier diodes and output filter capacitor The terminals of the secondary winding with the same name are respectively connected to the secondary rectifier diode. The positive electrode and the secondary rectifier diode The negative terminal of the secondary winding is connected to the negative terminal of the secondary winding, and the opposite terminals of the secondary winding are respectively connected to the secondary rectifier diode. The positive electrode and the secondary rectifier diode The negative terminal of the output filter capacitor is connected to the negative terminal. One end is respectively connected to the secondary rectifier diode The negative terminal, the secondary rectifier diode The negative terminal and the equivalent load resistance One end is connected to the output filter capacitor. The other end is connected to the secondary rectifier diode. The positive electrode, the secondary rectifier diode The positive terminal and the equivalent load resistance The other end is connected.

5. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 4, characterized in that: The control module includes a PWM controller, used to generate the PWM drive signal according to the input control parameters, and control the primary-side power switch transistor. The primary power switch transistor The primary power switch transistor and the primary side power switch The on or off state can be controlled to achieve MPPT or MEPT regulation.

6. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 5, characterized in that: in, The computing module also includes a subunit with the fastest response speed. The fastest response speed subunit is pre-programmed with a fastest response algorithm for adjusting the control parameters. The control module controls the on or off of each primary-side power switch according to the control parameters, achieving an optimal trade-off between MPPT, maximum efficiency, and response speed.

7. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 5, characterized in that: in, The computing module also includes an optimal power path subunit. The optimal power path subunit is pre-programmed with an optimal power path algorithm for adjusting the control parameters. The control module controls the on or off of each primary-side power switch according to the control parameters, achieving an optimal trade-off between MPPT, maximum efficiency, and power path.

8. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 3, characterized in that: in, The primary power switch The primary power switch transistor The primary power switch transistor and the primary side power switch It can be either MOSFET or IGBT.

9. The resonant multiport converter with multi-control quantity coordinated modulation according to claim 1, characterized in that: in, The resonant structure of the resonant converter unit includes a half-bridge or full-bridge resonant structure, a phase-shifting resonant structure, an asymmetric half-bridge or full-bridge resonant structure, a forward resonant structure, an LLC resonant structure, an LCC resonant structure, a CL composite resonant structure, a CLCC resonant structure, a resonant converter network using a transformer, and a resonant network using a wireless charging coil.

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