A multi-module reconfigurable inverter power distribution system

Abstract

This invention discloses a multi-module reconfigurable converter power distribution system, belonging to the field of power grid voltage control. The system includes a main circuit and a data communication and control module. The main circuit includes a low-voltage side power supply, a multi-module reconfigurable converter, and a high-voltage side load connected in sequence. The multi-module reconfigurable converter includes multiple reconfigurable bidirectional converters. The data communication and control module includes an input voltage sampling circuit, an output voltage sampling circuit, a drive circuit, and a main controller. The main controller is used to correct the phase shift angle based on the input voltage sampled by the input voltage sampling circuit and the total output voltage sampled by the output voltage sampling circuit. This allows the drive circuit to control the switching transistors in the multiple reconfigurable bidirectional converters based on the phase shift angle, achieving input voltage equalization and output voltage regulation for the multiple reconfigurable bidirectional converters. This balances the core contradiction between wide voltage gain coverage, high power expansion, and high-efficiency operation under all operating conditions.

Description

Technical Field

[0001] This invention relates to the field of power grid voltage control technology, and more specifically, to a multi-module reconfigurable converter power distribution system. Background Technology

[0002] Power transmission in new energy industrial parks is characterized by a wide range of variations. Traditional dual active bridge converters (DABs) have limited power regulation ranges, making them difficult to adapt to wide-range power fluctuation scenarios. Furthermore, power level upgrades are limited by the inherent characteristics of the topology, presenting significant technical bottlenecks and failing to meet the power transmission requirements of high-power applications. Meanwhile, while multi-module topologies with input-series output-parallel (ISOP) connections can expand voltage levels and power capacity, input voltage imbalances between modules can easily occur, causing individual modules to bear excessive voltage stress. This accelerates the aging of switching devices, shortens their lifespan, and reduces the long-term reliability of the system. Fixed phase-shift control cannot achieve optimal adaptation across the entire power domain. The complex control logic used in low- and medium-power modes easily generates control redundancy and switching redundancy losses, leading to a decline in conversion efficiency. The simplified control in high-power mode cannot guarantee the zero-voltage turn-on soft-switching characteristics of all switching transistors. In addition, traditional DAB converters mostly use fixed topologies and cannot dynamically adjust their operating modes according to the load power, making them difficult to adapt to wide-range dynamic power conversion requirements. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a multi-module reconfigurable converter power distribution system that balances the core contradictions of wide voltage gain coverage, high power expansion, and high-efficiency operation under all operating conditions.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0005] This invention provides a multi-module reconfigurable converter power distribution system, comprising a main circuit and a data communication and control module. The main circuit includes a low-voltage side power supply, a multi-module reconfigurable converter, and a high-voltage side load connected in sequence. The multi-module reconfigurable converter includes multiple reconfigurable bidirectional converters. The data communication and control module includes an input voltage sampling circuit, an output voltage sampling circuit, a drive circuit, and a main controller. The low-voltage side power supply is used to provide input voltage for each of the reconfigurable bidirectional converters, and the output voltage of the plurality of reconfigurable bidirectional converters is used to power the high-voltage side load; The input voltage sampling circuit is used to sample the input voltage of each of the reconfigurable bidirectional converters, and the output voltage sampling circuit is used to sample the total output voltage of the multiple reconfigurable bidirectional converters. The main controller is used to correct the phase shift angle based on the sampled input voltage and total output voltage, so that the driving circuit controls the switching transistors in the multiple reconfigurable bidirectional converters to turn on and off according to the phase shift angle, thereby realizing input voltage equalization and output voltage regulation of the multiple reconfigurable bidirectional converters.

[0006] Optionally, the main controller is used to correct the phase shift angle based on the sampled input voltage and output voltage, including: The main controller is used to perform difference calculation between the sampled total output voltage and the reference voltage to obtain a first voltage difference, and to compare the sampled multiple input voltages with the equalizing reference value to obtain multiple second voltage differences; to adjust the first voltage difference through a proportional-integral regulator to generate a base phase shift angle, and to adjust each of the second voltage differences through a proportional-integral regulator to generate multiple phase shift angle corrections; to sum the base phase shift angle with each of the phase shift angle corrections to obtain the corrected phase shift angle corresponding to each of the reconfigurable bidirectional converters.

[0007] Optionally, the reconfigurable bidirectional converter includes: Cascaded transformers; The primary-side full-bridge circuit includes a first primary-side half-bridge circuit consisting of a first primary-side switch, a fifth primary-side switch, and a second primary-side switch connected in series, and a second primary-side half-bridge circuit consisting of a third primary-side switch and a fourth primary-side switch connected in series. The first and second primary-side half-bridge circuits are connected in parallel with a first capacitor. The first and fifth primary-side switches, and the fifth and second primary-side switches, are respectively connected to the low-voltage side of the cascaded transformer via a second capacitor and a third capacitor. The third and fourth primary-side switches are connected to the center tap of the primary side of the cascaded transformer. The secondary-side full-bridge circuit includes a first secondary-side half-bridge circuit formed by a first secondary-side switch and a second secondary-side switch connected in series, and a second secondary-side half-bridge circuit formed by a third secondary-side switch and a fourth secondary-side switch connected in series. The first secondary-side half-bridge circuit and the second secondary-side half-bridge circuit are connected in parallel with a fourth capacitor and a fifth capacitor connected in series. The first secondary-side switch and the second secondary-side switch are connected to the same-name terminal on the high-voltage side of the cascaded transformer through a first inductor. The third secondary-side switch and the fourth secondary-side switch are connected to the non-same-name terminal on the high-voltage side of the cascaded transformer through a second inductor. The fourth capacitor and the fifth capacitor are connected to the center tap on the secondary side of the cascaded transformer.

[0008] Optionally, the cascaded transformer is formed by cascading two transformers, and the turns ratio of the two transformers is 1:n.

[0009] Optionally, the first inductor and the second inductor are AC clamping inductors, and both are formed by the leakage inductance of a cascaded transformer and an external inductor connected in series.

[0010] Optionally, the main controller is further configured to calculate the output power based on the sampled total output voltage, switch the control mode according to the output power, and control the switching transistors in the multiple reconfigurable bidirectional converters to turn on and off through the drive circuit according to the control mode.

[0011] Optionally, when the output power is lower than or equal to the first load power threshold, the control mode is a low-power mode, and the low-power mode uses single-phase-shift modulation; when the output power is higher than the first load power threshold and lower than or equal to the second load power threshold, the control mode is a medium-power mode, and the medium-power mode uses single-phase-shift modulation; when the output power is higher than the second load power threshold, the control mode is a high-power mode, and the high-power mode uses extended-phase-shift modulation.

[0012] Optionally, when the control mode is low power mode, the first primary-side switch is turned on, the fifth primary-side switch and the second primary-side switch are turned off, and the third primary-side switch and the fourth primary-side switch are complementaryly turned on; the input voltage of one of the transformers is a square wave that varies between 0 and the low-voltage side power supply voltage, and the input voltage of the other transformer remains at 0; The first and second secondary-side switches are complementaryly turned on, while the third and fourth secondary-side switches are turned off; the output voltage of one of the transformers is -V. C5 and V C4 A square wave that varies between the two, while the output voltage of the other transformer remains at 0, V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

[0013] Optionally, when the control mode is medium power mode, the first primary-side switch and the second primary-side switch are turned on, the fifth primary-side switch is turned off, and the third primary-side switch and the fourth primary-side switch are complementaryly turned on; the input voltage of both transformers is a square wave that varies between 0 and the low-voltage side power supply voltage; The first and second secondary-side switches are turned off, while the third and fourth secondary-side switches are complementaryly turned on; the output voltage of one of the transformers remains 0, and the output voltage of the other transformer is -V. C4 and VC5 A square wave that varies between V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

[0014] Optionally, when the control mode is high-power mode, the fifth primary-side switch is turned on, the first primary-side switch and the fourth primary-side switch are complementaryly turned on, and the second primary-side switch and the third primary-side switch are complementaryly turned on; the input voltage of both transformers is a square wave that varies between the positive and negative low-voltage side power supply voltages. The first and second secondary-side switching transistors are complementaryly turned on, and the third and fourth secondary-side switching transistors are complementaryly turned on; the output voltage of one of the transformers is -V. C5 and V C4 A square wave varying between these values, and the output voltage of the other transformer is -V. C4 and V C5 A square wave that varies between V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By cascading multiple reconfigurable bidirectional converters, the system decomposes the total high-voltage input task into various sub-modules. Each sub-module's switching transistors only need to withstand 1 / N of the total voltage, where N is the number of reconfigurable bidirectional converters. This allows the system to use low-cost, low-on-resistance, low-voltage devices to achieve high-voltage power conversion, significantly reducing hardware costs and switching losses. It solves the technical bottleneck that a single converter topology cannot directly withstand extremely high voltages, enabling the power distribution system to directly connect to medium- and high-voltage DC buses or drive high-voltage loads without the need for bulky power frequency transformers for initial voltage reduction. (2) A reconfigurable design is adopted. When a submodule fails, the main controller can quickly identify it and control the drive circuit to bypass or reconfigure the connection of the faulty module. In the case of partial module failure, the system can redistribute voltage stress by adjusting the phase shift angle and duty cycle of the remaining normal modules, so that the system can continue to operate in a derating state, avoiding the paralysis of the entire power distribution system due to a single point of failure, and greatly improving the continuity of power supply. At the same time, the internal circuit structure can be dynamically adjusted and the number of modules can be flexibly increased or decreased according to the actual voltage level and power transmission requirements of the system, so as to realize the elastic expansion of the overall topology. This design combines the variable structure characteristics of a single module with the ISOP topology scalability of multiple modules. It can rely on the flexible adjustment of the number of modules and the structural reconfiguration of a single module to make the overall converter have strong scene adaptability and can accurately match the actual needs of various medium and high voltage to low voltage high power conversion scenarios.

[0016] (3) The phase shift angle correction control strategy enables the system to maintain efficient operation under a wide range of input voltage changes and load fluctuations. In particular, it can smoothly transition during the switching between light and heavy loads and avoid voltage overshoot.

[0017] (4) A dual-loop control is adopted. The outer loop samples the high-voltage side output voltage and adjusts it by PI to achieve precise voltage regulation of the output voltage and maintain the stability of power transmission. The inner loop collects the low-voltage side input voltage of each module in real time and achieves voltage balance of the input side of multiple modules by dynamically correcting the phase shift angle of each module. This solves the problem of unbalanced input voltage between modules in the ISOP multi-module topology, avoids the excessive voltage stress on a single module, delays the aging of switching devices, and greatly improves the reliability of long-term system operation.

[0018] (5) A segmented phase-shift control strategy is adopted. Based on the power transmission requirements of the system, the segmented control is adapted to power. The low-power mode and the medium-power mode adopt single phase-shift modulation to reduce the control redundancy and switching redundancy losses caused by complex control, effectively improving the conversion efficiency of the low and medium power segments. The high-power mode is switched to extended phase-shift modulation to ensure the zero-voltage turn-on soft-switching characteristics of the full-power switch, reduce the switching losses of the high-power segment, and achieve optimal adaptation of the control strategy in the full power domain, so that the converter can maintain high efficiency in a wide power range. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a multi-module reconfigurable converter power distribution system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structural principle of a dual-loop control system provided in an embodiment of the present invention; Figure 3 A schematic diagram of a circuit structure for LTP mode provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the switching timing of a switching transistor in LTP mode, provided by an embodiment of the present invention. Figure 5 A schematic diagram of a circuit structure for MTP mode provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the switching timing of a switching transistor in MTP mode, provided by an embodiment of the present invention. Figure 7 A schematic diagram of a circuit structure for an HTP mode provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the switching timing of a switching transistor in HTP mode, provided as an embodiment of the present invention. Figure 9This is a schematic diagram of a steady-state simulation waveform in LTP mode provided by an embodiment of the present invention; Figure 10 This is a schematic diagram of a steady-state simulation waveform in MTP mode provided by an embodiment of the present invention; Figure 11 This is a schematic diagram of a steady-state simulation waveform under HTP mode provided in an embodiment of the present invention; Detailed Implementation The present invention will be further described below with reference to specific embodiments.

[0020] like Figure 1 As shown, Figure 1 This is a schematic diagram of a multi-module reconfigurable converter power distribution system provided in an embodiment of the present invention. The multi-module reconfigurable converter power distribution system includes a main circuit and a data communication and control module. The main circuit includes a low-voltage side power supply V connected in sequence. LV Multi-module reconfigurable converter and high-voltage side load V HV The multi-module reconfigurable converter includes multiple reconfigurable bidirectional converters, and the data communication and control module includes an input voltage sampling circuit, an output voltage sampling circuit, a drive circuit, and a main controller, wherein: The low-voltage side power supply V LV Used to provide input voltage V for each of the reconfigurable bidirectional converters in The output voltage V of the plurality of reconfigurable bidirectional converters o Used for the high-voltage side load V HV powered by; The input voltage sampling circuit is used to sample the input voltage V of each of the reconfigurable bidirectional converters. in Sampling is performed, and the output voltage sampling circuit is used to sample the total output voltage V of the multiple reconfigurable bidirectional converters. o The main controller performs sampling and uses the sampled input voltage V to... in and total output voltage V o The phase shift angle is adjusted so that the driving circuit controls the switching transistors in the multiple reconfigurable bidirectional converters to turn on and off according to the phase shift angle, thereby achieving input voltage equalization and output voltage regulation of the multiple reconfigurable bidirectional converters.

[0021] In topologies such as Dual Active Bridge (DAB) or Phase Shifted Full Bridge (PSFB), the phase shift angle typically refers to the electrical angle corresponding to the time delay between the drive signals of the primary and secondary bridge arms (H-bridges) of the transformer. Therefore, this phase shift angle refers to the electrical angle corresponding to the time delay between the drive signals of the primary and secondary full-bridge circuits in a cascaded transformer.

[0022] The embodiments of the present invention have the following beneficial effects: (1) By cascading multiple reconfigurable bidirectional converters, the system decomposes the total high-voltage input task into various sub-modules. Each sub-module's switching transistors only need to withstand 1 / N of the total voltage, where N is the number of reconfigurable bidirectional converters. This allows the system to use low-cost, low-on-resistance, low-voltage devices to achieve high-voltage power conversion, significantly reducing hardware costs and switching losses. It solves the technical bottleneck that a single converter topology cannot directly withstand extremely high voltages, enabling the power distribution system to directly connect to medium- and high-voltage DC buses or drive high-voltage loads without the need for bulky power frequency transformers for initial voltage reduction. (2) A reconfigurable design is adopted. When a submodule fails, the main controller can quickly identify it and control the drive circuit to bypass or reconfigure the connection of the faulty module. In the case of partial module failure, the system can redistribute voltage stress by adjusting the phase shift angle and duty cycle of the remaining normal modules, so that the system can continue to operate in a derating state, avoiding the paralysis of the entire power distribution system due to a single point of failure, and greatly improving the continuity of power supply. At the same time, the internal circuit structure can be dynamically adjusted and the number of modules can be flexibly increased or decreased according to the actual voltage level and power transmission requirements of the system, so as to realize the elastic expansion of the overall topology. This design combines the variable structure characteristics of a single module with the ISOP topology scalability of multiple modules. It can rely on the flexible adjustment of the number of modules and the structural reconfiguration of a single module to make the overall converter have strong scene adaptability and can accurately match the actual needs of various medium and high voltage to low voltage high power conversion scenarios.

[0023] (3) The phase shift angle correction control strategy enables the system to maintain efficient operation under a wide range of input voltage changes and load fluctuations. In particular, it can smoothly transition during the switching between light and heavy loads and avoid voltage overshoot.

[0024] like Figure 2 As shown, Figure 2 This is a schematic diagram illustrating the structural principle of a dual-loop control system provided in an embodiment of the present invention. Specifically, the main controller is used to correct the phase shift angle based on the sampled input voltage and output voltage, including: The main controller is used to process the sampled total output voltage V. o With reference voltage V oref Perform interpolation to obtain the first voltage difference ΔV1, and the multiple sampled input voltages V. in1 ~V inN (N is the number of reconfigurable bidirectional converters) and the equalization reference value V are respectively... inref (i.e., the average input voltages of N reconfigurable bidirectional converters) are compared to obtain multiple second voltage differences ΔV. 21 ~ΔV 2NThe first voltage difference δV1 is adjusted by a proportional-integral regulator to generate the base phase shift angle D. base And by adjusting each of the second voltage differences ΔV using a proportional-integral regulator. 21 ~ΔV 2N Multiple phase shift angle correction values ​​ΔD1~ΔD are generated. N The basic phase shift angle D base Each of the phase shift angle correction values ​​ΔD1~ΔD N By performing the addition and subtraction, the phase shift angle D corresponding to each of the reconfigurable bidirectional converters is obtained after correction. i = D base +ΔD i By correcting the phase shift angle, V in1 ≈V in2 ≈…≈V inN This achieves equalization of input pressure.

[0025] This invention employs a dual-loop control system. The outer loop samples the high-voltage side output voltage and uses PI regulation to achieve precise voltage regulation of the output voltage, maintaining the stability of power transmission. The inner loop collects the low-voltage side input voltage of each module in real time and achieves voltage balance on the input side of multiple modules by dynamically correcting the phase shift angle of each module. This solves the problem of unbalanced input voltage between modules in the ISOP multi-module topology, avoids excessive voltage stress on a single module, delays the aging of switching devices, and significantly improves the long-term reliability of the system.

[0026] The reconfigurable bidirectional converter includes: cascaded transformers; The primary-side full-bridge circuit includes a first primary-side switch S. p1 Fifth primary-side switch S p5 Second primary-side switch S p2 The first primary-side half-bridge circuit connected in series, and the third primary-side switch S p3 Fourth primary-side switch S p4 The second primary-side half-bridge circuit is connected in series, and the first and second primary-side half-bridge circuits are connected in parallel with the first capacitor C1. The first primary-side switching transistor S... p1 With the fifth primary-side switch S p5 Between, the fifth primary-side switch S p5 With the second primary-side switch S p2 The two terminals are connected to the low-voltage side of the cascaded transformer via the second capacitor C2 and the third capacitor C3, respectively. The third primary-side switch S... p3 Fourth primary-side switch S p4 The connection between the primary side center tap and the cascaded transformer; and, The secondary-side full-bridge circuit includes a first secondary-side switching transistor S. s1 Second auxiliary switch Ss2 The first secondary half-bridge circuit formed by series connection, and the third secondary switching transistor S s3 Fourth secondary switch S s4 The second secondary half-bridge circuit is formed by series connection, and the first secondary half-bridge circuit, the second secondary half-bridge circuit, and the fourth capacitor C4 and the fifth capacitor C5 connected in series are connected in parallel. The first secondary switch S s1 With the second auxiliary switch S s2 The first inductor L is between them s1 The third secondary switch S is connected to the same-name terminal on the high-voltage side of the cascaded transformer. s3 With the fourth secondary switch S s4 The second inductor L is between them s2 The fourth capacitor C4 and the fifth capacitor C5 are connected to the non-identical terminal on the high-voltage side of the cascaded transformer, and are connected to the center tap on the secondary side of the cascaded transformer.

[0027] The cascaded transformer is formed by cascading two transformers T1 and T2, and the turns ratio of the two transformers T1 and T2 is 1:n.

[0028] Wherein, the first inductor L s1 and the second inductor L s2 These are AC clamping inductors, and are all formed by the leakage inductance of cascaded transformers and external inductors connected in series.

[0029] Among them, S p1 and S p5 Let the midpoint be a, and let S be the midpoint. p3 and S p4 The midpoint of S is b. p5 and S p2 The midpoint is c, S s1 and S s2 The midpoint is d, S s3 and S s4 The midpoint is e.

[0030] Furthermore, the main controller is also configured to, based on the sampled total output voltage V o Calculate the output power P out According to the output power P out Switching control modes, and controlling the on and off of the switching transistors in the multiple reconfigurable bidirectional converters through the drive circuit according to the control mode.

[0031] Wherein, the output power P outWhen the load power is below or equal to the first load power threshold P1, the control mode is low transmission power (LTP) mode, which employs single phase shift modulation (SPS); the output power P out When the load power is higher than the first load power threshold P1 and lower than or equal to the second load power threshold P2, the control mode is Medium Transmission Power (MTP) mode, which employs single-phase-shift modulation; the output power P... out When the load power exceeds the second load power threshold P2, the control mode is a high-power (High Transmission Power, LTP) mode, which employs extended phase shift (EPS) modulation.

[0032] like Figure 3 and Figure 4 As shown, Figure 3 This is a schematic diagram of a circuit structure for LTP mode provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the switching timing of a switching transistor in LTP mode provided by an embodiment of the present invention. When the control mode is low-power mode, the first primary-side switching transistor S... p1 The fifth primary-side switch S is turned on. p5 and the second primary-side switch S p2 Turn off, the third primary-side switch S p3 and the fourth primary-side switch S p4 Complementary conduction; the input voltage V of one of the transformers T1 ab For 0 and the low-voltage side power supply voltage V LV A square wave that varies between the two, while the input voltage of the other transformer T2 remains at 0; The first secondary-side switch S s1 and the second secondary-side switch S s2 Complementary conduction, the third secondary-side switch S s3 and the fourth secondary switch S s4 Turn off; the output voltage V of one of the transformers T1 de -V C5 and V C4 A square wave that varies between these values, and the output voltage V of the other transformer T2. ef V remains at 0 C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

[0033] By integrating V during the switching cycle ab The voltage and current at the port, and the transmission power in LTP mode under boost conditions, can be expressed as: , Among them, P LTP Where P is the transmission power, N is the number of reconfigurable bidirectional converters, and P is the transmission power. Boost P represents the transmission power of a single reconfigurable bidirectional converter in boost mode. Boost_ab T represents the power transmitted through transformer T1 in a single reconfigurable bidirectional converter under boost conditions. S Let T1 be the converter operating cycle, n be the turns ratio of transformers T2 and T1, and v be the voltage. ab Let i be the voltage difference between points a and b. LS1 To pass through inductor L S1 The current, D P L is the electrical angle corresponding to the time delay between the drive signals of the primary bridge arm (H-bridge) and the secondary bridge arm (H-bridge) of the transformer. S1 For inductor L S1 The value of .

[0034] like Figure 5 and Figure 6 As shown, Figure 5 This is a schematic diagram of a circuit structure for MTP mode provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the switching timing of a switching transistor in MTP mode, provided by an embodiment of the present invention. When the control mode is medium power mode, the first primary-side switching transistor S... p1 and the second primary-side switch S p2 The fifth primary-side switch S is turned on. p5 Turn off, the third primary-side switch S p3 and the fourth primary-side switch S p4 Complementary conduction; the input voltage V of the two transformers T1 and T2 ab and V bc Both are at 0 and the low-voltage side power supply voltage V LV Square waves that vary between these intervals; The first secondary-side switch S s1 and the second secondary-side switch S s2 Turn off, the third secondary switch S s3 and the fourth secondary switch S s4 Complementary conduction; the output voltage V of one of the transformers T1 de The output voltage V of the other transformer T2 remains at 0. ef -V C4 and V C5 A square wave that varies between V C4 and VC5 These are the two output voltages of the reconfigurable bidirectional converter.

[0035] By integrating V during the switching cycle ab The voltage and current at the port, and the transmission power in MTP mode under boost conditions, can be expressed as: , By integrating V during the switching cycle bc The voltage and current at the port, and the transmission power in MTP mode under boost conditions, can be expressed as: , Combining the above two equations, the total transmission power of MTP mode under boost conditions is: , Among them, P MTP Where P is the transmission power, N is the number of reconfigurable bidirectional converters, and P is the transmission power. Boost P represents the transmission power of a single reconfigurable bidirectional converter in boost mode. Boost_ab P represents the power transmitted through transformer T1 in a single reconfigurable bidirectional converter under boost conditions. Boost_bc T represents the power transmitted through transformer T2 in a single reconfigurable bidirectional converter under boost conditions. S Let T1 be the converter operating cycle, n be the turns ratio of transformers T2 and T1, and v be the voltage. ab Let v be the voltage difference between points a and b. bc Let i be the voltage difference between points b and c. LS1 To pass through inductor L S1 The current, i LS2 To pass through inductor L S2 The current, D P L is the electrical angle corresponding to the time delay between the drive signals of the primary bridge arm (H-bridge) and the secondary bridge arm (H-bridge) of the transformer. S1 For inductor L S1 The value of L S2 For inductor L S2 The value of .

[0036] like Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of a circuit structure for an HTP mode provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the switching timing of a switching transistor in HTP mode, provided by an embodiment of the present invention. When the control mode is high-power mode, the fifth primary-side switching transistor is turned on (S). p5 The first primary-side switch S p1 and the fourth primary-side switch S p4 Complementary conduction, the second primary-side switch Sp2 and the third primary-side switch S p3 Complementary conduction; the input voltage V of the two transformers T1 and T2 ab and V bc Both are the positive and negative low-voltage side power supply voltages. V LV and V LV Square waves that vary between these intervals; The first secondary-side switch S s1 and the second secondary-side switch S s2 Complementary conduction, the third secondary-side switch S s3 and the fourth secondary switch S s4 Complementary conduction; the output voltage V of one of the transformers T1 de -V C5 and V C4 A square wave that varies between these values, and the output voltage V of the other transformer T2. ef -V C4 and V C5 A square wave that varies between V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

[0037] By integrating V during the switching cycle ab The voltage and current at the port, and the transmission power in HTP mode under boost conditions, can be expressed as: , By integrating V during the switching cycle bc The voltage and current at the port, and the transmission power in HTP mode under boost conditions, can be expressed as: , Combining the above two equations, the total transmission power of HTP mode under boost conditions is: , To ensure that there is no circulating current during converter operation, the inductance i is selected. Ls1 i Ls2 If the inductance is the same, then the transmission power of HTP mode under boost mode is: , Among them, P HTP Where P is the transmission power, N is the number of reconfigurable bidirectional converters, and P is the transmission power. Boost P represents the transmission power of a single reconfigurable bidirectional converter in boost mode. Boost_ab P represents the power transmitted through transformer T1 in a single reconfigurable bidirectional converter under boost conditions. Boost_bcT represents the power transmitted through transformer T2 in a single reconfigurable bidirectional converter under boost conditions. S Let T1 be the converter operating cycle, n be the turns ratio of transformers T2 and T1, and v be the voltage. ab Let v be the voltage difference between points a and b. bc Let i be the voltage difference between points b and c. LS1 To pass through inductor L S1 The current, i LS2 To pass through inductor L S2 The current, D P Let L be the electrical angle corresponding to the time delay between the drive signals of the primary side bridge arm (H-bridge) and the secondary side bridge arm (H-bridge) of the transformer, and D be the electrical angle corresponding to the time delay between the drive signals of the primary side bridge arm (H-bridge) and the secondary side bridge arm (H-bridge) of the transformer. S1 For inductor L S1 The value of L S2 For inductor L S2 The value of .

[0038] This invention employs a segmented phase-shift control strategy, which achieves power-adaptive segmented control based on the system's power transmission requirements. The low-power and medium-power modes use single-phase-shift modulation to reduce control redundancy and switching redundancy losses caused by complex control, effectively improving the conversion efficiency in the low and medium power ranges. The high-power mode switches to extended phase-shift modulation to ensure the zero-voltage turn-on soft-switching characteristics of the full-power switch, reducing switching losses in the high-power range. This achieves optimal adaptation of the control strategy across the entire power domain, enabling the converter to maintain high-efficiency operation over a wide power range.

[0039] To verify the effectiveness of the proposed ISOP-connected multi-module reconfigurable converter and its implementation method, simulation analysis was performed under LTP, MTP, and HTP modes. This simulation uses a three-module configuration with an input voltage of 1200V, an output voltage of 600V, and rated power of 1000W, 2000W, and 4000W per module in LTP, MTP, and HTP modes as an example for verification.

[0040] The input voltage is 1200V in all operating modes. Since the input terminals are connected in series, the theoretical average input voltage of each module should be 400V. Figure 9 , Figure 10 and Figure 11 The steady-state simulation waveforms of the multi-module reconfigurable converter power distribution system are shown in LTP mode, MTP mode and HTP mode respectively.

[0041] like Figure 9As shown, when operating in LTP mode, the input voltage of each module stabilizes at 400V within 0.05 seconds, the system output voltage stabilizes at 600V, the system output power stabilizes at 3000W, and the inductor current waveforms of each module are consistent with the theoretical settings; Figure 10 As shown, when operating in MTP mode, the input voltage of each module stabilizes at 400V within 0.04 seconds, the system output voltage stabilizes at 600V, the system output power stabilizes at 6000W, and the inductor current waveforms of each module are consistent with the theoretical settings; Figure 11 As shown, when operating in HTP mode, the input voltage of each module stabilizes at 400V before 0.02S, the output voltage of the system stabilizes at 600V, the output power of the system stabilizes at 12000W, and the inductor current waveform of each module is consistent with the theoretical setting.

[0042] The steady-state simulation results using the three modules as an example show that the system can quickly enter a steady-state operating state under LTP, MTP, and HTP operating modes. The input voltage of each module is precisely stabilized at the theoretical set value of 400V, and the system output voltage remains consistently stable at 600V. The output power remains stable at different power levels of 3000W, 6000W, and 12000W, and the inductor current waveforms of each module are highly consistent with the theoretical settings, with no significant deviation. These simulation results fully verify the excellent performance of the dual-loop control architecture of this invention. The outer loop for output voltage regulation and the inner loop for input-side voltage equalization can achieve precise voltage regulation and equalization control, effectively solving the technical problem of unbalanced input voltage between modules in the ISOP multi-module topology, ensuring that each module can withstand voltage stress evenly under different power modes. This also verifies the rationality and adaptability of the power adaptive segmented phase-shift control strategy and reconfigurable variable topology of this invention. The converter can accurately switch operating modes and match the corresponding modulation methods according to actual power transmission requirements, achieving stable and accurate power transmission over a wide power range of 3000W to 12000W. Furthermore, simulation verification of the three-module expansion structure also demonstrates the practical feasibility of the multi-module expandable design of this invention, which can adapt to different voltage levels and power transmission requirements by flexibly configuring the number of modules. This simulation analysis verifies the overall effectiveness of the proposed ISOP-based multi-module reconfigurable converter and its implementation method, proving that it can meet the actual needs of wide-range, high-power conversion.

Claims

1. A multi-module reconfigurable converter power distribution system, characterized in that, The multi-module reconfigurable converter power distribution system includes a main circuit and a data communication and control module. The main circuit includes a low-voltage side power supply, a multi-module reconfigurable converter, and a high-voltage side load connected in sequence. The multi-module reconfigurable converter includes multiple reconfigurable bidirectional converters. The data communication and control module includes an input voltage sampling circuit, an output voltage sampling circuit, a drive circuit, and a main controller. The low-voltage side power supply is used to provide input voltage for each of the reconfigurable bidirectional converters, and the output voltage of the plurality of reconfigurable bidirectional converters is used to power the high-voltage side load; The input voltage sampling circuit is used to sample the input voltage of each of the reconfigurable bidirectional converters, and the output voltage sampling circuit is used to sample the total output voltage of the multiple reconfigurable bidirectional converters. The main controller is used to correct the phase shift angle based on the sampled input voltage and total output voltage, so that the driving circuit controls the switching transistors in the multiple reconfigurable bidirectional converters to turn on and off according to the phase shift angle, thereby realizing input voltage equalization and output voltage regulation of the multiple reconfigurable bidirectional converters.

2. The multi-module reconfigurable converter power distribution system according to claim 1, characterized in that, The main controller is used to correct the phase shift angle based on the sampled input and output voltages, including: The main controller is used to perform difference calculation between the sampled total output voltage and the reference voltage to obtain a first voltage difference, and to compare the sampled multiple input voltages with the equalizing reference value to obtain multiple second voltage differences; to adjust the first voltage difference through a proportional-integral regulator to generate a base phase shift angle, and to adjust each of the second voltage differences through a proportional-integral regulator to generate multiple phase shift angle corrections; to sum the base phase shift angle with each of the phase shift angle corrections to obtain the corrected phase shift angle corresponding to each of the reconfigurable bidirectional converters.

3. The multi-module reconfigurable converter power distribution system according to claim 1, characterized in that, The reconfigurable bidirectional converter includes: Cascaded transformers; The primary-side full-bridge circuit includes a first primary-side half-bridge circuit consisting of a first primary-side switch, a fifth primary-side switch, and a second primary-side switch connected in series, and a second primary-side half-bridge circuit consisting of a third primary-side switch and a fourth primary-side switch connected in series. The first and second primary-side half-bridge circuits are connected in parallel with a first capacitor. The first and fifth primary-side switches, and the fifth and second primary-side switches, are respectively connected to the low-voltage side of the cascaded transformer via a second capacitor and a third capacitor. The third and fourth primary-side switches are connected to the center tap of the primary side of the cascaded transformer. The secondary-side full-bridge circuit includes a first secondary-side half-bridge circuit formed by a first secondary-side switch and a second secondary-side switch connected in series, and a second secondary-side half-bridge circuit formed by a third secondary-side switch and a fourth secondary-side switch connected in series. The first secondary-side half-bridge circuit and the second secondary-side half-bridge circuit are connected in parallel with a fourth capacitor and a fifth capacitor connected in series. The first secondary-side switch and the second secondary-side switch are connected to the same-name terminal on the high-voltage side of the cascaded transformer through a first inductor. The third secondary-side switch and the fourth secondary-side switch are connected to the non-same-name terminal on the high-voltage side of the cascaded transformer through a second inductor. The fourth capacitor and the fifth capacitor are connected to the center tap on the secondary side of the cascaded transformer.

4. The multi-module reconfigurable converter power distribution system according to claim 3, characterized in that, The cascaded transformer is formed by cascading two transformers, and the turns ratio of the two transformers is 1:n.

5. The multi-module reconfigurable converter power distribution system according to claim 3, characterized in that, The first inductor and the second inductor are AC clamping inductors, and both are formed by the leakage inductance of the cascaded transformer and an external inductor connected in series.

6. The multi-module reconfigurable converter power distribution system according to claim 4, characterized in that, The main controller is also used to calculate the output power based on the sampled total output voltage, switch the control mode according to the output power, and control the switching transistors in the multiple reconfigurable bidirectional converters to turn on and off according to the control mode through the drive circuit.

7. The multi-module reconfigurable converter power distribution system according to claim 6, characterized in that, When the output power is lower than or equal to the first load power threshold, the control mode is a low power mode, and the low power mode uses single phase-shift modulation; when the output power is higher than the first load power threshold and lower than or equal to the second load power threshold, the control mode is a medium power mode, and the medium power mode uses single phase-shift modulation; when the output power is higher than the second load power threshold, the control mode is a high power mode, and the high power mode uses extended phase-shift modulation.

8. The multi-module reconfigurable converter power distribution system according to claim 7, characterized in that, When the control mode is low power mode, the first primary-side switch is turned on, the fifth primary-side switch and the second primary-side switch are turned off, and the third primary-side switch and the fourth primary-side switch are complementaryly turned on; the input voltage of one of the transformers is a square wave that varies between 0 and the low-voltage side power supply voltage, and the input voltage of the other transformer remains at 0; The first and second secondary-side switches are complementaryly turned on, while the third and fourth secondary-side switches are turned off; the output voltage of one of the transformers is -V. C5 and V C4 A square wave that varies between the two, while the output voltage of the other transformer remains at 0, V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

9. The multi-module reconfigurable converter power distribution system according to claim 7, characterized in that, When the control mode is medium power mode, the first primary-side switch and the second primary-side switch are turned on, the fifth primary-side switch is turned off, and the third primary-side switch and the fourth primary-side switch are complementaryly turned on; the input voltage of both transformers is a square wave that varies between 0 and the low-voltage side power supply voltage; The first and second secondary-side switches are turned off, while the third and fourth secondary-side switches are complementaryly turned on; the output voltage of one of the transformers remains 0, and the output voltage of the other transformer is -V. C4 and V C5 A square wave that varies between V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

10. The multi-module reconfigurable converter power distribution system according to claim 7, characterized in that, When the control mode is high power mode, the fifth primary-side switch is turned on, the first primary-side switch and the fourth primary-side switch are complementaryly turned on, and the second primary-side switch and the third primary-side switch are complementaryly turned on; the input voltage of both transformers is a square wave that varies between the positive and negative low-voltage side power supply voltage; The first and second secondary-side switching transistors are complementaryly turned on, and the third and fourth secondary-side switching transistors are complementaryly turned on; the output voltage of one of the transformers is -V. C5 and V C4 A square wave varying between these values, and the output voltage of the other transformer is -V. C4 and V C5 A square wave that varies between V C4 and V C5 These are the two output voltages of the reconfigurable bidirectional converter.

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