A Hybrid Control Method for Resonant Converter Circuits

Abstract

This invention provides a hybrid control method for a resonant converter circuit, relating to the field of power electronics technology. The resonant converter circuit includes a primary-side full-bridge, a secondary-side full-bridge, and a resonant cavity. The primary-side and secondary-side full-bridges are connected via the resonant cavity. The primary-side full-bridge includes two parallel arms, and the secondary-side full-bridge includes two parallel arms, each arm comprising two series-connected semiconductor devices. The hybrid control method for the resonant converter circuit includes: when any semiconductor device in either the primary or secondary full-bridge fails, controlling the switching state of the other semiconductor device in the arm containing the failed semiconductor device according to the fault type; and determining the switching frequency and phase shift angle of the corresponding semiconductor device in the resonant converter circuit based on the fault location and a preset matching rule, thus achieving hybrid control of the resonant converter circuit. This invention can improve the reliability of the resonant converter circuit operation.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically, to a hybrid control method for a resonant converter circuit. Background Technology

[0002] With the rapid development of power electronics technology towards higher power density, higher efficiency, and higher reliability, various DC-DC converter circuits have been widely used in new energy power generation, energy storage systems, electric vehicle on-board chargers, data center power supplies, and aerospace power supplies. Among them, resonant converter circuits have become one of the mainstream topologies for medium- and high-power isolation conversion scenarios due to their advantages such as strong soft-switching characteristics, low switching losses, and low electromagnetic interference.

[0003] In related technologies, most existing control methods for resonant converter circuits are designed for healthy operating conditions and mainly adopt a single control strategy, which leads to a deviation between the actual output power and the target output power, affecting the reliability of the resonant converter circuit operation. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the reliability of resonant converter circuit operation.

[0005] To address the above problems, this invention provides a hybrid control method for resonant converter circuits.

[0006] In a first aspect, the present invention provides a hybrid control method for a resonant converter circuit, which is applied to the resonant converter circuit. The resonant converter circuit includes a primary-side full bridge, a secondary-side full bridge, and a resonant cavity. The primary-side full bridge and the secondary-side full bridge are connected through the resonant cavity. The primary-side full bridge includes two parallel bridge arms, and the secondary-side full bridge includes two parallel bridge arms. Each bridge arm includes two series-connected semiconductor devices. The hybrid control method for the resonant converter circuit includes: When any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails, the switching state of another semiconductor device in the bridge arm where the failed semiconductor device is located is controlled according to the fault type. Based on the fault location, the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit are determined using a preset matching rule.

[0007] Optionally, controlling the switching state of another semiconductor device in the bridge arm containing the faulty semiconductor device according to the fault type includes: When the fault type is a short circuit fault, control the other semiconductor device to switch to the off state; When the fault type is an open circuit fault, control the other semiconductor device to switch to the on state.

[0008] Optionally, determining the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit based on the fault location and a preset matching rule includes: Obtain the target power, primary voltage, and secondary voltage of the resonant converter circuit; Based on the fault location, the target power, the primary voltage, and the secondary voltage, the switching frequency and phase shift angle are obtained through the matching rules, which are generated by time-domain simulation based on multiple preset operating state data sets.

[0009] Optionally, the operating status data set includes a preset switching frequency, a preset phase shift angle, a preset input voltage, and a preset output voltage corresponding to a preset fault location; it also includes: The secondary equivalent voltage is obtained based on the preset output voltage through a preset first conversion relationship; The primary-side equivalent voltage is obtained based on the preset input voltage and through a preset second conversion relationship. A piecewise voltage vector is generated based on the equivalent voltage of the secondary side and the equivalent voltage of the primary side; The primary resonant current is obtained from the segmented voltage vector through a preset state-space relationship; The average transmission power corresponding to the operating status data group is obtained through a preset power relationship based on the preset switching frequency, the preset phase shift angle, the primary equivalent voltage, and the primary resonant current. A matching data group corresponding to the operating status data group is generated based on the preset fault location, preset switching frequency, preset phase shift angle, preset input voltage, preset output voltage, and corresponding average transmission power of the operating status data group. The matching rules are generated based on all the matching data sets.

[0010] Optionally, the first conversion relationship satisfies: ; The second conversion relationship satisfies: ; The segmented voltage vector satisfies: ; Among them, U S The equivalent voltage of the secondary side is calculated as γ. S V is the equivalent bridge arm voltage coefficient on the secondary side, n is the transformer turns ratio in the resonant converter circuit, and V O U is the preset output voltage. P γ is the primary-side equivalent voltage. P V is the equivalent bridge arm coefficient of the original side. iU is the preset input voltage. k Let T be the segmented voltage vector corresponding to the k-th switching interval, and U be the transpose of the vector. S，k U is the secondary-side segmented voltage corresponding to the k-th switching interval of the secondary-side equivalent voltage. P，k It is the primary side segment voltage corresponding to the kth switching interval of the primary side equivalent voltage.

[0011] Optionally, the state-space relationship satisfies: ; The primary-side resonant current satisfies: ; Where x(t) is the state variable, Let A be the first derivative of the state variable, and B be a preset constant matrix. k U is a pre-defined piecewise input matrix. k Let i be the segmented voltage vector. L1 (t) represents the primary resonant current, u C1 (t) represents the voltage of the primary resonant capacitor, i L2 (t) represents the secondary resonant current, u C2 (t) represents the voltage of the secondary resonant capacitor, and T is the transpose.

[0012] Optionally, the power relationship satisfies: ; ; ; ; ; ; ; Where P is the average transmission power, f S t is the preset switching frequency. k Let t be the starting time of the k-th segment interval. k+1 U represents the end time of the k-th segment interval. P，k The primary-side equivalent voltage U P The equivalent voltage corresponding to the k-th segment interval in the diagram, i L1 (t) represents the primary resonant current that varies with time t, and [t0, t1], [t1, t2], [t2, t3], and [t3, t4] represent one switching period T. S The four segmented intervals, and D is the preset phase shift angle.

[0013] Optionally, the resonant cavity includes a primary resonant unit, an excitation inductor, a transformer, and a secondary resonant unit. The primary side of the transformer is connected to the primary full-bridge via the primary resonant unit. One end of the excitation inductor is connected to one end of the primary side of the transformer, and the other end of the excitation inductor is connected to the other end of the primary side of the transformer. The secondary side of the transformer is connected to the secondary full-bridge via the secondary resonant unit.

[0014] Optionally, the primary-side resonant unit includes a primary-side inductor and a primary-side capacitor. One end of the primary-side inductor is connected to the midpoint of one arm of the primary-side full bridge, and the other end of the primary-side inductor is connected to one end of the primary side of the transformer. One end of the primary-side capacitor is connected to the midpoint of the other arm of the primary-side full bridge, and the other end of the primary-side capacitor is connected to the other end of the primary side of the transformer.

[0015] Optionally, the secondary resonant unit includes a secondary inductor and a secondary capacitor. One end of the secondary inductor is connected to the midpoint of one arm of the secondary full-bridge, and the other end of the secondary inductor is connected to one end of the secondary side of the transformer. One end of the secondary capacitor is connected to the midpoint of the other arm of the secondary full-bridge, and the other end of the secondary capacitor is connected to the other end of the secondary side of the transformer.

[0016] In a second aspect, the present invention provides a hybrid control device for a resonant converter circuit, comprising: The control module is used to control the switching state of another semiconductor device in the bridge arm where the faulty semiconductor device is located, according to the fault type, when any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails. The adjustment module is used to determine the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit according to the fault location and a preset matching rule.

[0017] Thirdly, the present invention provides an electronic device, including a memory and a processor; The memory is used to store computer programs; The processor is configured to implement the hybrid control method for the resonant converter circuit as described in the first aspect when executing the computer program.

[0018] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the hybrid control method for the resonant converter circuit as described in the first aspect.

[0019] The beneficial effects of the hybrid control of the resonant converter circuit of this invention are as follows: the primary-side full-bridge is used to invert the input DC voltage into a high-frequency AC square wave and inject energy into the resonant cavity; the secondary-side full-bridge is used to receive the high-frequency AC energy transmitted through the resonant cavity and transformer and rectify it into a DC output voltage. The resonant cavity, as the core unit for energy transmission and resonance, has a symmetrical design in its primary and secondary sides, consisting of components such as a primary-side resonant inductor, a primary-side resonant capacitor, a magnetizing inductor, a secondary-side resonant inductor, and a secondary-side resonant capacitor. It utilizes resonant characteristics to achieve zero-voltage turn-on or zero-current turn-off of the switching transistors, thereby significantly reducing switching losses and improving conversion efficiency. When any semiconductor device in either the primary-side or secondary-side full-bridge experiences a short-circuit or open-circuit fault, the switching state of the other semiconductor device in the bridge arm containing the faulty device is specifically controlled according to the fault type. This effectively reconstructs the resonant converter circuit from a full-bridge operating state to a half-bridge operating state, preventing the fault from escalating and ensuring that the basic power transmission channel remains uninterrupted. Based on this, the corresponding switching frequency and phase shift angle are quickly determined according to the fault location (primary-side fault or secondary-side fault) using preset matching rules (such as offline pre-generated lookup tables) to compensate for the power gap caused by the full-bridge degrading to a half-bridge. Compared with existing technologies that rely solely on a single control strategy or simple shutdown, the coordinated control of "bridge arm reconfiguration and parameter matching" enables the conversion circuit to maintain output power stability even after device failure, avoiding output voltage drops or insufficient load power supply. This significantly improves the continuous operation capability of the conversion circuit under abnormal operating conditions, thereby enhancing the operational stability and fault ride-through capability of the resonant conversion circuit in high-reliability application scenarios. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a hybrid control method for a resonant converter circuit according to an embodiment of the present invention. Figure 2 This is a circuit diagram of the resonant converter circuit according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the circuit mode equivalent circuit of an embodiment of the present invention; Figure 4 This is a schematic diagram of the control logic in an embodiment of the present invention; Figure 5 This is a schematic diagram of the frequency-phase shift angle operating point under healthy conditions according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the frequency-phase-shift angle operating point under the primary-side fault state according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the frequency-phase-shift angle operating point under secondary-side fault conditions according to an embodiment of the present invention. Figure 8This is a schematic diagram of the theoretical and simulated waveforms of the inductor current under healthy conditions according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the theoretical and simulated waveforms of the inductor current under primary-side fault conditions according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the theoretical and simulated waveforms of the inductor current under secondary-side fault conditions according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the theoretical and simulated waveforms of the capacitor voltage under healthy conditions according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the theoretical and simulated waveforms of the capacitor voltage under primary-side fault conditions according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the theoretical and simulated waveforms of the capacitor voltage under secondary-side fault conditions according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the structure of a hybrid control device for a resonant converter circuit according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: Q1 - First semiconductor device; Q2 - Second semiconductor device; Q3 - Third semiconductor device; Q4 - Fourth semiconductor device; Q5 - Fifth semiconductor device; Q6 - Sixth semiconductor device; Q7 - Seventh semiconductor device; Q8 - Eighth semiconductor device; L r1 - Primary inductance; C r1 - Primary capacitance; L m - Magnetizing inductance; T r - Transformer; L r2 - Secondary inductance; C r2 - Secondary capacitor; V i - Input voltage; V O - Output voltage. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0023] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0024] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0025] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0026] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0027] In related technologies, existing control methods typically employ single control modes such as pulse frequency modulation (PFM) or phase-shift modulation (PSM), which can maintain stable output power relatively well when the converter circuit is in a healthy state. However, when the converter circuit operates under high-frequency, high-voltage, and high-current conditions for extended periods, and semiconductor devices (such as MOSFETs) in the primary or secondary bridge arms experience short-circuit or open-circuit faults, the adjustment capability of a single control strategy is often insufficient to cope with the topology changes caused by the fault. After a fault occurs, a topology reconfiguration method from a full-bridge to a half-bridge is usually used to maintain basic operation, but the equivalent excitation voltage is halved after reconfiguration, resulting in a significant decrease in power transmission capability. At this time, simply changing the switching frequency or adjusting the phase shift angle cannot effectively compensate for this power gap, making it difficult for the actual output power to track the target output power, resulting in a significant deviation between the two. If this deviation is not corrected in time, it will lead to a drop in output voltage, insufficient load power supply, and in severe cases, the converter circuit cannot maintain normal operation and must shut down for protection, thus significantly reducing the operational reliability of the system under fault conditions and limiting the widespread application of resonant converter circuits in high-reliability scenarios such as aerospace, medical power supplies, and energy storage systems.

[0028] To address the problems existing in the aforementioned related technologies, embodiments of the present invention provide a hybrid control method for a resonant converter circuit.

[0029] like Figure 1 As shown in the figure, an embodiment of the present invention provides a hybrid control method for a resonant converter circuit, which is applied to the resonant converter circuit. The resonant converter circuit includes a primary-side full bridge, a secondary-side full bridge, and a resonant cavity. The primary-side full bridge and the secondary-side full bridge are connected through the resonant cavity. The primary-side full bridge includes two parallel bridge arms, and the secondary-side full bridge includes two parallel bridge arms. Each bridge arm includes two series-connected semiconductor devices.

[0030] Specifically, such as Figure 2 As shown, the primary-side full-bridge consists of two parallel bridge arms. Each bridge arm includes two series-connected semiconductor devices. Semiconductor device Q1 and semiconductor device Q2 are connected in series to form one bridge arm, and semiconductor device Q3 and semiconductor device Q4 are connected in series to form the other bridge arm. The primary-side full-bridge is used to convert the DC voltage V input to the input terminal... i The high-frequency AC square wave is inverted and energy is injected into the resonant cavity. The secondary-side full-bridge also consists of two parallel arms, each arm comprising two series-connected semiconductor devices. Semiconductor device Q5 and semiconductor device Q6 are connected in series to form one arm, and semiconductor device Q7 and semiconductor device Q8 are connected in series to form the other arm. The secondary-side full-bridge receives the high-frequency AC energy transmitted through the transformer in the resonant cavity and rectifies it into a DC output voltage V. O The load is supplied through the output terminal. The resonant cavity typically consists of a primary-side resonant inductor L. r1 Primary resonant capacitor C r1 Transformer T r Magnetizing inductance L m and secondary resonant inductor L r2 Secondary resonant capacitor C r2 It consists of components such as [list of components], used to achieve resonant energy transfer and voltage conversion.

[0031] The hybrid control method for the resonant converter circuit includes: S110, when any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails, the switching state of another semiconductor device in the bridge arm where the failed semiconductor device is located is controlled according to the fault type.

[0032] Specifically, in this conversion circuit, each semiconductor device in the primary-side full-bridge and secondary-side full-bridge may experience short-circuit or open-circuit faults due to prolonged operation under high-frequency, high-voltage, and high-current conditions. When any semiconductor device in the primary-side or secondary-side full-bridge fails, the switching state of the other semiconductor device in the same bridge arm as the faulty semiconductor device needs to be controlled accordingly based on the fault type (short-circuit fault or open-circuit fault) to prevent the fault from escalating and to complete the bridge arm topology reconfiguration. If a short-circuit fault occurs, to prevent the bridge arm containing the faulty device from forming a direct current path that could further damage the circuit, the other semiconductor device in the same bridge arm should be switched to the off state, thereby blocking the short-circuit current path and protecting other devices in the conversion circuit from damage. If an open-circuit fault occurs, the other semiconductor device in the same bridge arm should be switched to the on state, so that it, together with other components in the bridge arm containing the faulty device, forms an equivalent half-bridge structure, ensuring that current can continue to flow and maintaining the ability to apply AC excitation to the resonant network.

[0033] For example, taking a primary-side full-bridge as an example, it includes two bridge arms. The left bridge arm is composed of a first semiconductor device Q1 and a second semiconductor device Q2 connected in series, and the right bridge arm is composed of a third semiconductor device Q3 and a fourth semiconductor device Q4 connected in series. When a short-circuit fault occurs in the first semiconductor device Q1 of the left bridge arm, the second semiconductor device Q2 in the same bridge arm is switched to the off state to prevent the input voltage V from being turned off. i A large current is generated directly to ground through the short-circuited Q1 and the on-circuit Q2, burning out the devices. When the first semiconductor device Q1 in the left bridge arm experiences an open-circuit fault, the second semiconductor device Q2 in the same bridge arm is switched to the on state, allowing current to flow through Q2 and the transformer T. r The primary winding forms a circuit to maintain the resonant cavity (by the primary inductance L). r1 Primary capacitance C r1 Magnetizing inductance L m Energy injection (composition). Similarly, for the secondary-side full bridge, its left arm consists of the fifth semiconductor device Q5 and the sixth semiconductor device Q6 connected in series, and the right arm consists of the seventh semiconductor device Q7 and the eighth semiconductor device Q8 connected in series. When the sixth semiconductor device Q6 in the left arm of the secondary side experiences a short-circuit fault, the controller switches the fifth semiconductor device Q5 in the same arm to the off state; when the sixth semiconductor device Q6 experiences an open-circuit fault, the controller switches the fifth semiconductor device Q5 to the on state. Through the above-mentioned targeted control of the switching state of the other device in the same arm according to the fault type, the original full-bridge state can be equivalently reconstructed into a half-bridge state, thereby maintaining a basic power transmission channel after a fault occurs, providing the necessary topological foundation for subsequent compensation of power gaps through frequency and phase adjustment and achieving fault ride-through.

[0034] S120, based on the fault location, determine the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit according to a preset matching rule.

[0035] Specifically, when any semiconductor device in either the primary or secondary full-bridge circuit fails and completes bridge arm topology reconfiguration, the faulty side effectively changes from a full-bridge operating state to a half-bridge operating state. Its equivalent bridge arm voltage coefficient γ drops from 1 to 1 / 2, resulting in a halving of the effective excitation voltage across the resonant network and generating approximately 50% power deficit. To compensate for this power deficit, the corresponding switching frequency and phase shift angle need to be determined based on the fault location (primary-side or secondary-side fault) and the operating data of the resonant converter circuit, using a pre-defined matching rule (such as an offline pre-generated lookup table). This matching rule is pre-built based on a time-domain average power model, using the fault location, input voltage, output voltage, and target power as indices to store the switching frequency and phase shift angle parameters that make the converter circuit's output power approach the target value.

[0036] For example, taking an input voltage of 750V, an output voltage of 750V, and a target power of 45kW as an example, when the conversion circuit is in a healthy state, the operating point given by the matching rules is a switching frequency of 10.57kHz and a phase shift angle of 5.95°. When any semiconductor device (such as Q1) in the primary-side full-bridge fails and completes reconstruction, the primary side becomes a half-bridge (γ). P =1 / 2, γ S =1), the matching rule is based on the location information of "primary-side fault" and combined with the current operating data of the conversion circuit. The corresponding control parameters are read from the lookup table: switching frequency 12.54kHz, phase shift angle 51.55°. The frequency is increased to adjust the resonant network gain, and the phase shift angle is increased significantly to a positive angle, so that the primary-side voltage leads the secondary-side voltage, jointly compensating for the power gap caused by the halving of the primary-side excitation. When any semiconductor device in the secondary-side full-bridge (such as Q5) fails and completes reconstruction, the secondary side becomes a half-bridge (γ). P =1, γ S =1 / 2), the matching rule is based on the location information of "secondary side fault" and combined with the current operating data of the converter circuit. The corresponding control parameters are read as a switching frequency of 6.22kHz and a phase shift angle of -69.73°. The frequency is reduced to increase the resonant network gain, and the negative phase shift angle makes the secondary side voltage lead the primary side voltage, compensating for the power gap caused by the halving of the secondary side reflected voltage. By matching the preset rules according to the fault location, the control parameters can be obtained quickly without complex real-time calculations, realizing power compensation and stable operation under fault conditions.

[0037] In this embodiment, the primary-side full-bridge inverts the input DC voltage into a high-frequency AC square wave and injects energy into the resonant cavity. The secondary-side full-bridge receives the high-frequency AC energy transmitted through the resonant cavity and transformer and rectifies it into a DC output voltage. The resonant cavity, as the core unit for energy transmission and resonance, has a symmetrical design in its primary and secondary sides. It consists of components such as a primary-side resonant inductor, a primary-side resonant capacitor, a magnetizing inductor, a secondary-side resonant inductor, and a secondary-side resonant capacitor. It utilizes resonant characteristics to achieve zero-voltage turn-on or zero-current turn-off of the switching transistors, thereby significantly reducing switching losses and improving conversion efficiency. When any semiconductor device in either the primary or secondary full-bridge experiences a short-circuit or open-circuit fault, the switching state of the other semiconductor device in the same bridge arm as the faulty device is controlled accordingly based on the fault type. This effectively reconstructs the resonant converter circuit from a full-bridge operating state to a half-bridge operating state, preventing the fault from escalating and ensuring uninterrupted basic power transmission. Based on this, the corresponding switching frequency and phase shift angle are quickly determined according to the fault location (primary-side fault or secondary-side fault) using preset matching rules (such as offline pre-generated lookup tables) to compensate for the power gap caused by the full-bridge degrading to a half-bridge. Compared with existing technologies that rely solely on a single control strategy or simple shutdown, the coordinated control of "bridge arm reconfiguration and parameter matching" enables the conversion circuit to maintain output power stability even after device failure, avoiding output voltage drops or insufficient load power supply. This significantly improves the continuous operation capability of the conversion circuit under abnormal operating conditions, thereby enhancing the operational stability and fault ride-through capability of the resonant conversion circuit in high-reliability application scenarios.

[0038] Optionally, controlling the switching state of another semiconductor device in the bridge arm containing the faulty semiconductor device according to the fault type includes: When the fault type is a short circuit fault, control the other semiconductor device to switch to the off state; When the fault type is an open circuit fault, control the other semiconductor device to switch to the on state.

[0039] Specifically, when a faulty semiconductor device experiences a short circuit, it loses its blocking capability, essentially becoming a conductive wire. If another semiconductor device in the same bridge arm remains conductive at this time, the positive and negative terminals of the input power supply will form a direct current path through these two conductive devices, generating a massive short-circuit current that could instantly burn out the bridge arm or even the entire conversion circuit. Therefore, it is essential to switch the other semiconductor device in the same bridge arm to the off state to block the direct current path. Although the faulty device is still short-circuited, the current cannot form a loop because the other device is off, thus protecting the safety of other devices in the conversion circuit.

[0040] For example, taking the left arm of the primary-side full bridge as an example, this arm is composed of a first semiconductor device Q1 and a second semiconductor device Q2 connected in series, with the first semiconductor device Q1 connected to the positive input terminal (V). i+ The second semiconductor device Q2 is connected to the negative input terminal V. i- (Or ground). When the first semiconductor device Q1 experiences a short circuit fault, it loses its blocking capability and becomes equivalent to a wire. If the second semiconductor device Q2 remains in the conducting state at this time, the input positive terminal V... i+ The first semiconductor device Q1, which is short-circuited, and the second semiconductor device Q2, which is conductive, are directly connected to the input negative terminal V. i- This short circuit creates a direct current, instantly generating a huge current that burns out the second semiconductor device Q2 and may even damage the input power supply Vi. Therefore, the controller must immediately switch the second semiconductor device Q2 to the off state, cutting off the direct circuit. At this time, although the first semiconductor device Q1 is still short-circuited, the current cannot form a path because the second semiconductor device Q2 is off, thus protecting the other parts of the conversion circuit. Thereafter, the conversion circuit continues to operate in a half-bridge configuration, relying on the cooperation of the body diode (or parallel freewheeling diode) of the second semiconductor device Q2 and the other bridge arm (composed of the third semiconductor device Q3 and the fourth semiconductor device Q4 connected in series).

[0041] Furthermore, when a faulty semiconductor device experiences an open-circuit fault, it completely blocks the current, effectively breaking the circuit. In this situation, if the other semiconductor device in the same bridge arm remains operational, the entire bridge arm will be unable to provide a current path for the resonant network, and the conversion circuit will completely lose its power transmission capability. Therefore, it is necessary to switch the other semiconductor device in the same bridge arm to the conducting state (or keep it conducting) so that it, together with other components in the bridge arm containing the faulty device, forms an equivalent half-bridge structure, ensuring that current can continue to flow and maintaining the ability to apply AC excitation to the resonant network.

[0042] For example, taking the left arm of the primary-side full-bridge as an example, this arm is composed of a first semiconductor device Q1 and a second semiconductor device Q2 connected in series. When the first semiconductor device Q1 experiences an open-circuit fault, Q1 completely blocks the current and cannot conduct. At this time, if the second semiconductor device Q2 still operates in the normal complementary mode (i.e., Q2 conducts when Q1 is off), but Q1 is already open-circuited, the current cannot flow through Q1, resulting in the current flowing through L... r1 (Primary inductance), C r1 (Primary capacitor), L m (Magnetic inductor), T r The resonant network composed of (transformers), etc., cannot obtain positive excitation. Therefore, the controller needs to switch the second semiconductor device Q2 to the on state and keep it on (or operate according to the preset fault-tolerant drive logic) so that the current can flow from V... i(Input voltage) The positive terminal passes through the other bridge arm (involving Q3 and Q4) and the resonant cavity (L). r1 C r1 ), T r (Transformer), then returns to V via the second semiconductor device Q2 (or its body diode). i (Input voltage) negative terminal, forming a complete current loop. In this way, the converter circuit can continue to inject energy into the resonant network in a half-bridge configuration, maintaining the current to V. O Power transfer on the (output voltage) side.

[0043] In this optional embodiment, when a short-circuit fault occurs, switching the other device to the off state effectively blocks the direct current path, preventing the short-circuit current from burning out the device, preventing the fault from escalating, and protecting the safety of the conversion circuit and other circuit components. When an open-circuit fault occurs, switching the other device to the on state maintains the integrity of the current flow path, ensuring that the resonant network can continue to receive AC excitation, allowing the conversion circuit to maintain basic operating capability in an equivalent half-bridge structure. Through differentiated control strategies, a smooth topology reconfiguration from a full-bridge structure to a half-bridge structure is achieved for the faulty bridge arm. This avoids the entire system shutting down due to a single device failure and provides the necessary topological foundation for subsequent compensation of power deficits through coordinated frequency and phase shift angle adjustments. This significantly improves the fault ride-through capability and operational reliability of the resonant conversion circuit under semiconductor device failure conditions.

[0044] Optionally, determining the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit based on the fault location and a preset matching rule includes: Obtain the target power, primary voltage, and secondary voltage of the resonant converter circuit; Based on the fault location, the target power, the primary voltage, and the secondary voltage, the switching frequency and phase shift angle are obtained through the matching rules, which are generated by time-domain simulation based on multiple preset operating state data sets.

[0045] Specifically, the target power (i.e., the desired output power value, such as 45kW), primary input voltage (such as 750V), and secondary output voltage (such as 750V) under the current operating conditions are first obtained. When a fault occurs and the bridge arm reconfiguration is completed, the controller uses the fault location (primary fault or secondary fault) and the above three parameters as indices to quickly match and obtain the corresponding switching frequency and phase shift angle through preset matching rules. The matching rule is pre-built based on time-domain simulation. In offline mode, it iterates through various possible combinations of data such as fault location, target power, primary voltage, and secondary voltage. For each set of operating conditions, a two-dimensional scan is performed within the allowable switching frequency range and phase shift angle range. The actual output power under each (frequency, phase shift angle) combination is calculated by using piecewise linear state-space equations and average transmission power formula. The operating point that makes the output power close to the target power while taking into account efficiency and soft switching performance is found. The set of (frequency, phase shift angle) and the corresponding operating condition parameters (fault location, target power, primary voltage, secondary voltage) are stored in a lookup table to form a mapping rule from operating condition parameters to control parameters.

[0046] For example, taking an input voltage of 750V, an output voltage of 750V, and a target power of 45kW as an example, the time-domain simulation traverses a large number of combinations within the frequency range of 6kHz to 14kHz and the phase shift angle range of -180° to 180°, calculating the output power under each combination. When the fault location is a primary-side fault, the simulation finds that a frequency of 12.54kHz and a phase shift angle of 51.55° can make the output power closest to 45kW and have good soft-switching performance, so this set of parameters is stored in the matching rules; when the fault location is a secondary-side fault, the simulation determines a frequency of 6.22kHz and a phase shift angle of -69.73° as the operating point.

[0047] In this optional embodiment, when an actual fault occurs, there is no need to solve complex equations in real time. The switching frequency and phase shift angle can be obtained within microseconds simply by looking up tables based on the current fault location, target power, primary voltage, and secondary voltage. This significantly reduces the complexity of online calculations, transferring complex time-domain simulation calculations to the offline stage. This significantly improves the real-time control response speed, meeting the requirements for rapid fault ride-through. Furthermore, the matching rules generated based on precise time-domain analysis ensure the accuracy of power compensation after a fault, enabling the actual output power to accurately track the target power and effectively compensate for the power gap caused by the full-bridge degrading to a half-bridge. Simultaneously, by traversing all possible operating conditions in advance, the stability and reliability of control parameters across the entire operating range are guaranteed. After a semiconductor device failure, the circuit can quickly and accurately switch to a suitable operating point, maintaining stable output voltage and output power, significantly improving the fault ride-through capability and operational reliability of the resonant converter circuit.

[0048] Optionally, the operating status data set includes a preset switching frequency, a preset phase shift angle, a preset input voltage, and a preset output voltage corresponding to a preset fault location; it also includes: The secondary equivalent voltage is obtained based on the preset output voltage through a preset first conversion relationship; The primary-side equivalent voltage is obtained based on the preset input voltage and through a preset second conversion relationship. A piecewise voltage vector is generated based on the equivalent voltage of the secondary side and the equivalent voltage of the primary side; The primary resonant current is obtained from the segmented voltage vector through a preset state-space relationship; The average transmission power corresponding to the operating status data group is obtained through a preset power relationship based on the preset switching frequency, the preset phase shift angle, the primary equivalent voltage, and the primary resonant current. A matching data group corresponding to the operating status data group is generated based on the preset fault location, preset switching frequency, preset phase shift angle, preset input voltage, preset output voltage, and corresponding average transmission power of the operating status data group. The matching rules are generated based on all the matching data sets.

[0049] Optionally, the first conversion relationship satisfies: ; The second conversion relationship satisfies: ; The segmented voltage vector satisfies: ; Among them, U S The equivalent voltage of the secondary side is calculated as γ. S V is the equivalent bridge arm voltage coefficient on the secondary side, which is 1 for a full-bridge circuit and 1 / 2 for a half-bridge circuit. n is the transformer turns ratio in the resonant converter circuit, the ratio of the number of turns in the primary winding to the number of turns in the secondary winding. O U is the preset output voltage. P γ is the primary-side equivalent voltage. P This is the equivalent bridge arm coefficient of the original side, which is 1 for a full bridge and 1 / 2 for a half bridge. i U is the preset input voltage. k Let T be the segmented voltage vector corresponding to the k-th switching interval, and U be the transpose of the vector. S，k The equivalent voltage applied to the primary resonant network within the k-th switching interval of the secondary side is the equivalent voltage applied to the primary resonant network within the k-th switching interval, which remains constant within the interval. U P，kThe primary side segment voltage corresponding to the kth switching interval of the primary side equivalent voltage is the equivalent voltage of the secondary side voltage converted to the primary side within the kth switching interval, which remains constant within the interval.

[0050] Optionally, the state-space relationship satisfies: ; The primary-side resonant current satisfies: ; Where x(t) is a state variable describing the dynamic state of the resonant converter circuit at time t, and is a 4×1 column vector. Let L be the first derivative of the state variable, the rate of change of the state variable with time, reflecting the dynamic characteristics of the system, and be a 4×1 column vector. A is a preset constant matrix describing the coupling relationship between state variables and between state variables themselves, derived from the resonant conversion circuit parameters (primary inductance L). r1 Primary capacitance C r1 Magnetizing inductance L m Secondary inductor L r2 Secondary capacitor C r2 The transformer turns ratio n and equivalent load determine the constant value, which remains unchanged in the four switching intervals and is a 4×4 constant matrix. k The predefined piecewise input matrix describes the piecewise voltage vector U. k How does it act on each state variable, whose value varies with the switching interval k, forming a 4×2 matrix, U k Let i be the segmented voltage vector, which is a 2×1 column vector. L1 (t) represents the primary resonant current flowing through the primary resonant inductor L. r1 instantaneous current, u C1 (t) represents the voltage of the primary resonant capacitor, and the primary resonant capacitor C r1 The instantaneous voltage at both ends, i L2 (t) represents the secondary resonant current flowing through the secondary resonant inductor L. r2 instantaneous current, u C2 (t) represents the voltage of the secondary resonant capacitor, and the secondary resonant capacitor C... r2 The instantaneous voltage across the two ends, where T is the transpose.

[0051] Optionally, the power relationship satisfies: ; ; ; ; ; ; ; where P is the average transmission power, the average power transmitted by the conversion circuit within one switching period, f S is the preset switching frequency, t k is the starting time of the k-th segmented interval, t k+1 is the ending time of the k-th segmented interval, U P，k is the equivalent voltage corresponding to the k-th segmented interval in the primary-side equivalent voltage U P iis the primary-side resonant current varying with time t, the instantaneous current flowing through the primary-side resonant inductor L L1 r1 r1 r1 S The four segmented intervals of a switching period T, and D is the preset phase-shift angle.

[0052] The segmented intervals are shown in the following table:

[0053] It should be noted that this relationship only uses 0 < D < 1, that is, the primary-side voltage leads the secondary-side voltage. If the secondary-side voltage leads the primary-side voltage, that is, a reverse phase difference appears (such as bidirectional energy flow, motor regenerative braking, or inverter four-quadrant operation), then -1 < D < 0. At this time, the direction of the voltage gain and the transmission power is opposite to that in the positive value interval. Usually, it satisfies G(D)= G( D), where G(D) is the voltage gain function, and G(-D) is the voltage gain function when the preset phase-shift angle is negative. Therefore, the complete phase-shift control relationship is divided into two intervals: 0 < D < 1 corresponds to the primary-side voltage leading and the power being transmitted forward;<​​Specifically, the secondary-side equivalent voltage is obtained based on the preset output voltage through a preset first conversion relationship. This involves using the transformer turns ratio and the secondary-side equivalent bridge arm voltage coefficient to convert the secondary-side DC voltage to the primary side, serving as the equivalent AC voltage applied to the resonant network from the secondary side. Simultaneously, the primary-side equivalent voltage is obtained based on the preset input voltage through a preset second conversion relationship. This involves using the primary-side equivalent bridge arm voltage coefficient to convert the input DC voltage into the equivalent AC voltage applied to the resonant network from the primary side. Then, a piecewise voltage vector is generated based on the secondary-side equivalent voltage and the primary-side equivalent voltage. This vector is a two-dimensional input vector, with its two components representing the primary-side equivalent voltage and the secondary-side equivalent voltage, respectively. These two components undergo positive and negative changes according to a preset modal timing sequence within four switching intervals of one switching cycle, forming a piecewise constant input excitation. Next, the piecewise voltage vector is substituted into the preset state-space relationship, i.e., the piecewise linear state-space equation is solved. Within each switching interval, the rate of change of the state variables is jointly determined by the system matrix, input matrix, and piecewise voltage vector. The instantaneous waveform of the primary resonant current is obtained through recursive solution. Then, based on the preset switching frequency, preset phase shift angle, primary equivalent voltage, and primary resonant current, the average transmission power is calculated through the preset power relationship. Specifically, within one switching cycle, the product of the primary equivalent voltage and the primary resonant current in each of the four switching intervals is integrated, and the four integral values ​​are summed and divided by the switching cycle to obtain the average transmission power under this operating condition. Based on this, a matching data set corresponding to the operating state data set is generated according to the preset fault location, preset switching frequency, preset phase shift angle, preset input voltage, preset output voltage, and the calculated average transmission power. That is, the fault location, input voltage, output voltage, switching frequency, and phase shift angle are used as input parameters, and the calculated average transmission power is used as the output parameter, forming a complete record from operating condition parameters to control parameters and then to performance indicators. Finally, the above process is repeated for all preset operating conditions (traversing all possible fault locations, input voltages, output voltages, switching frequencies, and phase shift angle combinations). Matching rules are generated based on all calculated matching data sets, that is, the fault location, input voltage, output voltage, target power are associated with the corresponding switching frequency and phase shift angle and stored to generate complete matching rules (i.e., lookup tables). Thus, each matching data set in the matching rules can be used to filter out the operating point that makes the output power meet the target.

[0055] It should be noted that during the offline generation of the matching rules (lookup table), the switching frequency and phase shift angle must meet preset range constraints. Specifically, the preset range of the switching frequency is determined based on the resonant frequency of the resonant converter circuit, the switching characteristics of the semiconductor devices, and the design margin of the magnetic components. For example, when the resonant frequency is 10kHz, the switching frequency can be set in the first interval of 10.5kHz to 14kHz with a phase shift angle of 0° to 180°, or in the second interval of 6kHz to 9.5kHz with a phase shift angle of -180° to 0°. The preset range of the phase shift angle is determined based on the phase difference adjustment capability between the primary and secondary equivalent voltages and the soft-switching implementation conditions, and is typically set between -180° and 180°. During the time-domain simulation traversal, only the switching frequency and phase shift angle combinations within the above preset ranges are calculated and filtered; operating points outside the range are directly excluded. By limiting the frequency and phase shift angle boundaries, it is possible to effectively prevent control parameters from exceeding safety thresholds such as device withstand voltage, switching losses, or magnetic saturation of magnetic components after a fault. This prevents magnetic component saturation due to excessively low frequency or a sharp increase in switching losses due to excessively high frequency, while also preventing energy backflow or deterioration of soft-switching conditions caused by excessively large phase shift angles. Furthermore, limiting the search space to a feasible region significantly reduces the computational load of offline simulation and online table lookup, improving the efficiency of matching rule construction and real-time response speed. Therefore, the preset range constraints ensure the safe and stable operation of the converter circuit under fault conditions and provide clear boundary conditions for efficiently and accurately matching suitable control parameters.

[0056] In this optional embodiment, by using a precise piecewise linear state-space model and power integral relationship, the impact of waveform distortion on power transmission during half-bridge operation after fault reconstruction can be accurately captured, avoiding errors caused by simplified methods such as the fundamental approximation method. Directly associating fault location, input voltage, output voltage, target power, and control parameters eliminates the need for intermediate calculations during online table lookups, resulting in fast response times. This meets the stringent real-time requirements of fault ride-through, thus providing an accurate, fast, and reliable parameter matching foundation for high-fault-tolerant control.

[0057] Optionally, the resonant cavity includes a primary resonant unit, an excitation inductor, a transformer, and a secondary resonant unit. The primary side of the transformer is connected to the primary full-bridge via the primary resonant unit. One end of the excitation inductor is connected to one end of the primary side of the transformer, and the other end of the excitation inductor is connected to the other end of the primary side of the transformer. The secondary side of the transformer is connected to the secondary full-bridge via the secondary resonant unit.

[0058] Optionally, the primary-side resonant unit includes a primary-side inductor and a primary-side capacitor. One end of the primary-side inductor is connected to the midpoint of one arm of the primary-side full bridge, and the other end of the primary-side inductor is connected to one end of the primary side of the transformer. One end of the primary-side capacitor is connected to the midpoint of the other arm of the primary-side full bridge, and the other end of the primary-side capacitor is connected to the other end of the primary side of the transformer.

[0059] Optionally, the secondary resonant unit includes a secondary inductor and a secondary capacitor. One end of the secondary inductor is connected to the midpoint of one arm of the secondary full-bridge, and the other end of the secondary inductor is connected to one end of the secondary side of the transformer. One end of the secondary capacitor is connected to the midpoint of the other arm of the secondary full-bridge, and the other end of the secondary capacitor is connected to the other end of the secondary side of the transformer.

[0060] In this optional embodiment, such as Figure 2 As shown, the primary-side resonant unit consists of a primary-side inductor L r1 and primary side capacitance C r1 Composition, L r1 One end is connected to one arm of the primary full-bridge (e.g., the midpoint of the left arm, i.e., the connection point between the first semiconductor device Q1 and the second semiconductor device Q2), L r1 The other end is connected to transformer T r One end of the original edge (as the named end), C r1 One end is connected to the other arm of the primary full-bridge (e.g., the midpoint of the right arm, i.e., the connection point between the third semiconductor device Q3 and the fourth semiconductor device Q4), C r1 The other end is connected to transformer T r The other end of the primary winding (such as the opposite-named end) forms a primary resonant circuit. Magnetizing inductance L m Then connected in parallel to transformer T r The two ends of the primary side, i.e., one end is connected to transformer T. r One end of the primary circuit is connected to transformer T. r The other end of the primary side is used to characterize transformer T. r The excitation characteristics are an important component of the resonant cavity. The secondary resonant unit consists of the secondary inductor L. r2 and secondary capacitor C r2 Composition, L r2 One end is connected to one arm of the secondary full bridge (e.g., the connection point between the fifth semiconductor device Q5 and the sixth semiconductor device Q6), L r2 The other end is connected to transformer T r At one end of the secondary side, C r2 One end connects to the other arm of the secondary full bridge (e.g., the connection point between the seventh semiconductor device Q7 and the eighth semiconductor device Q8), C r2 The other end is connected to transformer Tr At the other end of the secondary side, a secondary resonant circuit is formed. Through the above connection method, the high-frequency AC square wave generated by the primary-side full-bridge (due to the input voltage V) i The power supply passes sequentially through the primary resonant unit (L) r1 C r1 ),transformer Tr Secondary resonant unit (L r2 C r2 The voltage is transmitted to the secondary side of the full-bridge circuit and output to the output voltage V. O The inductance and capacitance of the primary-side resonant unit and the magnetizing inductance L in the secondary-side resonant unit are related. m Both sides participate in the resonant process to achieve voltage transformation and power transfer. Simultaneously, the resonant characteristics enable the switching transistors to operate in a soft-switching state, reducing switching losses and improving conversion efficiency. This symmetrical structure allows both the primary and secondary sides to resonate, supporting not only bidirectional power transfer but also maintaining high gain regulation capability over a wide voltage range, providing a circuit foundation for subsequent fault reconfiguration and hybrid control.

[0061] Furthermore, such as Figure 3 The diagram shows the equivalent circuit for the modes that a CLLLC converter will exhibit within one switching cycle. The four modes correspond to... and The four polar combinations, namely , , and The resonant cavity topology remained unchanged across the four modes. , , , and All participate in resonance. Here, u1 is the AC square wave voltage output of the primary-side full-bridge, and the primary-side full-bridge (Q1 to Q4) will input DC V. i The excitation voltage applied to the resonant cavity after inversion, u2', is the equivalent voltage at the secondary side full-bridge input terminal referred to the primary side.

[0062] like Figure 4 The diagram shows the control block diagram of the resonant converter circuit. The input is the error signal e. A PI controller and a lookup table are respectively assigned to the healthy state, primary-side fault, and secondary-side fault states. The circuit selects between these three branches based on different states. The lookup table module outputs frequency and phase shift angle control parameters adapted to different operating conditions based on the error signal. Then, a selection switch switches the control parameters of different channels, ultimately generating control signals to drive eight switches, Q1 to Q8.

[0063] like Figure 5 As shown, this figure is a contour plot of the power characteristics of the resonant converter circuit under healthy conditions, with the horizontal axis representing the switching frequency f. s(Unit: kHz, range: 10.5 to 14 kHz), the vertical axis represents the phase shift angle D (range: 0 to 1), the color scale on the right represents the output power P (unit: kW, range: 0 to 500 kW). The markings in the figure include the target power P=45kW equal power line represented by the black solid line, the zero voltage switching (ZVS) boundary represented by the red dashed line, and the operating point marked by the red circle. It intuitively presents the distribution law of the output power of the conversion circuit with the switching frequency and phase shift angle under healthy conditions, the target power trajectory, and the boundary of the soft switching operating area.

[0064] like Figure 6 As shown, this figure is a contour plot of the power characteristics under primary-side fault conditions, with the horizontal axis representing the switching frequency f. s (Unit: kHz, range: 10.5 to 14 kHz), the vertical axis represents the phase shift angle D (range: 0 to 1), and the color scale on the right represents the output power P (unit: kW, range: 0 to 250 kW). The markings in the figure include the target power P=45 kW equal power line represented by the black solid line, the ZVS (zero voltage switching) boundary represented by the red dashed line, and the operating point marked by the red circle. It intuitively presents the distribution law of the output power of the converter circuit with the switching frequency and phase shift angle under the primary side fault state, the target power trajectory, and the boundary of the soft switching operating area.

[0065] like Figure 7 As shown, this figure is a contour plot of the power characteristics under secondary-side fault conditions, with the horizontal axis representing the switching frequency f. s (Unit: kHz, range: 6 to 9.5 kHz), the vertical axis represents the phase shift angle D (range: -1 to 0), and the color scale on the right represents the output power P (unit: kW, range: 0 to 250 kW). The markings in the figure include the target power P=45 kW equal power line represented by the black solid line, the ZVS (zero voltage switching) boundary represented by the red dashed line, and the operating point marked by the red circle. It intuitively presents the distribution law of the output power of the converter circuit with the switching frequency and phase shift angle under secondary side fault conditions, the target power trajectory, and the boundary of the soft switching operating area.

[0066] like Figure 8 The figure shows the current waveform verification under healthy operating conditions. The horizontal axis represents time (in μs), and the vertical axis represents current (in A). The labels include: the blue solid line represents the primary resonant current model value i. Lr1 The model, with the red solid line representing the excitation current model value i Lm The model, with the yellow solid line representing the model value i of the secondary resonant current, Lr2 The model shows the simulated value of the primary resonant current i, represented by the blue dashed line. Lr1 Simulation; the red dashed line represents the simulated value of the excitation current i. Lm Simulation; the yellow dashed line represents the simulated value of the secondary resonant current i. Lr2Simulation results show a high degree of agreement between the waveform trends and the actual current model, verifying the accuracy of the current model under healthy operating conditions. For example... Figure 9 The figure shows the current waveform verification diagram under primary-side fault conditions. The horizontal axis represents time (in μs), and the vertical axis represents current (in A). The labels are the same as those in the diagram. Figure 8 Consistent with the simulation, after reconstructing the half-bridge topology under primary-side fault conditions, the model and simulated current waveforms remain highly consistent, verifying the accuracy of the current model and the feasibility of the fault reconstruction strategy under primary-side fault conditions. Figure 10 The figure shows the current waveform verification diagram under secondary side fault conditions. The horizontal axis represents time (in μs), and the vertical axis represents current (in A). The labels are the same as those in the figure. Figure 8 The model and simulation current waveforms remained highly consistent after the half-bridge topology was reconstructed under secondary-side fault conditions, verifying the accuracy of the current model and the feasibility of the fault reconstruction strategy under secondary-side fault conditions.

[0067] like Figure 11 The figure shows the capacitor voltage waveform verification under healthy operating conditions. The horizontal axis represents time (in μs), and the vertical axis represents voltage (in V). The labels include: the blue solid line represents the primary resonant capacitor voltage model value v. Cr1 The model, with the red solid line representing the model value v of the secondary resonant capacitor voltage. Cr2 The model shows the simulated value of the primary resonant capacitor voltage v represented by the blue dashed line. Cr1 Simulation; the red dashed line represents the simulated value v of the secondary resonant capacitor voltage. Cr2 Simulation results show a high degree of agreement between the waveform trends, verifying the accuracy of the capacitor voltage model under healthy operating conditions. For example... Figure 12 The figure shown is a verification diagram of the capacitor voltage waveform under primary-side fault conditions. The horizontal axis represents time (in μs), and the vertical axis represents voltage (in V). The labels are the same as those in the diagram. Figure 11 Consistent with the simulation, after reconstructing the half-bridge topology under primary-side fault conditions, the model and simulated capacitor voltage waveforms remain highly consistent, verifying the accuracy of the capacitor voltage model and the feasibility of the fault reconstruction strategy under primary-side fault conditions. Figure 13 As shown, this is a verification diagram of the capacitor voltage waveform under secondary fault conditions. The horizontal axis represents time (in μs) and the vertical axis represents voltage (in V). The labeling is consistent with (a). After reconstructing the half-bridge topology under secondary fault conditions, the model and the simulated capacitor voltage waveform remain highly consistent, verifying the accuracy of the capacitor voltage model under secondary fault conditions and the feasibility of the fault reconstruction strategy.

[0068] like Figure 14 As shown, an embodiment of the present invention provides a hybrid control device 140 for a resonant converter circuit, comprising: Control module 141 is used to control the switching state of another semiconductor device in the bridge arm where the faulty semiconductor device is located, according to the fault type, when any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails. The adjustment module 142 is used to determine the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit according to the fault location and a preset matching rule.

[0069] The hybrid control device for the resonant converter circuit in this embodiment is used to implement the hybrid control method for the resonant converter circuit as described above. Its advantages over the prior art are the same as the advantages of the hybrid control method for the resonant converter circuit compared to the prior art, and will not be repeated here.

[0070] like Figure 15 As shown, an electronic device 150 provided in this embodiment of the invention includes a memory 151 and a processor 152; the memory 151 is used to store a computer program; the processor 152 is used to implement the hybrid control method of the resonant converter circuit as described above when the computer program is executed.

[0071] Alternatively, an electronic device 150 includes a memory 151 and a processor 152 coupled to the memory 151; the memory 151 is configured to store a computer program; the processor 152 is configured to perform the following operations when the computer program is executed: When any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails, the switching state of another semiconductor device in the bridge arm where the failed semiconductor device is located is controlled according to the fault type. Based on the fault location, the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit are determined using a preset matching rule.

[0072] This invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the hybrid control method for the resonant converter circuit described above.

[0073] Alternatively, a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the following operations: When any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails, the switching state of another semiconductor device in the bridge arm where the failed semiconductor device is located is controlled according to the fault type. Based on the fault location, the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit are determined using a preset matching rule.

[0074] Electronic device 150, which can serve as a server or client of the present invention, is described below as an example of a hardware device applicable to various aspects of the present invention. Electronic device 150 is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 150 can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0075] Electronic device 150 includes a computing unit that can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) or a computer program loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The computing unit, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0076] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. In this application, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs. Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units can be implemented in hardware or as software functional units.

[0077] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A hybrid control method for a resonant converter circuit, characterized in that, The circuit is applied to a resonant converter circuit, which includes a primary-side full-bridge, a secondary-side full-bridge, and a resonant cavity. The primary-side full-bridge and the secondary-side full-bridge are connected through the resonant cavity. The primary-side full-bridge includes two parallel bridge arms, and the secondary-side full-bridge includes two parallel bridge arms. Each bridge arm includes two series-connected semiconductor devices. The hybrid control method for the resonant converter circuit includes: When any semiconductor device in the primary-side full bridge or the secondary-side full bridge fails, the switching state of another semiconductor device in the bridge arm where the failed semiconductor device is located is controlled according to the fault type. Based on the fault location, the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit are determined according to a preset matching rule. The step of determining the switching frequency and phase shift angle of the semiconductor device corresponding to the resonant converter circuit according to the fault location and a preset matching rule includes: Obtain the target power, primary voltage, and secondary voltage of the resonant converter circuit; Based on the fault location, the target power, the primary voltage, and the secondary voltage, the switching frequency and phase shift angle are obtained through the matching rules, which are generated by time-domain simulation based on multiple preset operating state data sets. The operating status data set includes a preset switching frequency, preset phase shift angle, preset input voltage, and preset output voltage corresponding to a preset fault location; it also includes: The secondary equivalent voltage is obtained based on the preset output voltage through a preset first conversion relationship; The primary-side equivalent voltage is obtained based on the preset input voltage and through a preset second conversion relationship. A piecewise voltage vector is generated based on the equivalent voltage of the secondary side and the equivalent voltage of the primary side; The primary resonant current is obtained from the segmented voltage vector through a preset state-space relationship; The average transmission power corresponding to the operating status data group is obtained through a preset power relationship based on the preset switching frequency, the preset phase shift angle, the primary equivalent voltage, and the primary resonant current. A matching data group corresponding to the operating status data group is generated based on the preset fault location, preset switching frequency, preset phase shift angle, preset input voltage, preset output voltage, and corresponding average transmission power of the operating status data group. The matching rules are generated based on all the matching data sets.

2. The hybrid control method for the resonant converter circuit according to claim 1, characterized in that, The method of controlling the switching state of another semiconductor device in the bridge arm containing the faulty semiconductor device according to the fault type includes: When the fault type is a short circuit fault, control the other semiconductor device to switch to the off state; When the fault type is an open circuit fault, control the other semiconductor device to switch to the on state.

3. The hybrid control method for the resonant converter circuit according to claim 1, characterized in that, The first conversion relationship satisfies: ； The second conversion relationship satisfies: ； The segmented voltage vector satisfies: ； Among them, U S The equivalent voltage of the secondary side is calculated as γ. S V is the equivalent bridge arm voltage coefficient on the secondary side, n is the transformer turns ratio in the resonant converter circuit, and V O U is the preset output voltage. P γ is the primary-side equivalent voltage. P V is the equivalent bridge arm coefficient of the original side. i U is the preset input voltage. k Let T be the segmented voltage vector corresponding to the k-th switching interval, and U be the transpose of the vector. S，k U is the secondary-side segmented voltage corresponding to the k-th switching interval of the secondary-side equivalent voltage. P，k It is the primary side segment voltage corresponding to the kth switching interval of the primary side equivalent voltage.

4. The hybrid control method for the resonant converter circuit according to claim 1, characterized in that, The state-space relationships satisfy: ； The primary-side resonant current satisfies: ； Where x(t) is the state variable, Let A be the first derivative of the state variable, and B be a preset constant matrix. k U is a pre-defined piecewise input matrix. k Let i be the segmented voltage vector. L1 (t) represents the primary resonant current, u C1 (t) represents the primary resonant capacitor voltage, i L2 (t) represents the secondary resonant current, u C2 (t) represents the voltage of the secondary resonant capacitor, and T is the transpose.

5. The hybrid control method for the resonant converter circuit according to claim 1, characterized in that, The power relationship satisfies: ； ； ； ； ； ； ； Where P is the average transmission power, f S t is the preset switching frequency. k Let t be the starting time of the k-th segment interval. k+1 U represents the end time of the k-th segment interval. P，k The primary-side equivalent voltage U P The equivalent voltage corresponding to the k-th segment interval in the diagram, i L1 (t) represents the primary resonant current that varies with time t, and [t0, t1], [t1, t2], [t2, t3], and [t3, t4] represent one switching period T. S The four segmented intervals, and D is the preset phase shift angle.

6. The hybrid control method for the resonant converter circuit according to claim 1, characterized in that, The resonant cavity includes a primary resonant unit, an excitation inductor, a transformer, and a secondary resonant unit. The primary side of the transformer is connected to the primary full-bridge via the primary resonant unit. One end of the excitation inductor is connected to one end of the primary side of the transformer, and the other end of the excitation inductor is connected to the other end of the primary side of the transformer. The secondary side of the transformer is connected to the secondary full-bridge via the secondary resonant unit.

7. The hybrid control method for the resonant converter circuit according to claim 6, characterized in that, The primary-side resonant unit includes a primary-side inductor and a primary-side capacitor. One end of the primary-side inductor is connected to the midpoint of one arm of the primary-side full bridge, and the other end of the primary-side inductor is connected to one end of the primary side of the transformer. One end of the primary-side capacitor is connected to the midpoint of the other arm of the primary-side full bridge, and the other end of the primary-side capacitor is connected to the other end of the primary side of the transformer.

8. The hybrid control method for the resonant converter circuit according to claim 6, characterized in that, The secondary resonant unit includes a secondary inductor and a secondary capacitor. One end of the secondary inductor is connected to the midpoint of one arm of the secondary full-bridge, and the other end of the secondary inductor is connected to one end of the secondary side of the transformer. One end of the secondary capacitor is connected to the midpoint of the other arm of the secondary full-bridge, and the other end of the secondary capacitor is connected to the other end of the secondary side of the transformer.

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