Control method and device of resonant converter, controller and resonant converter

Abstract

The application provides a control method and device of a resonant converter, a controller and the resonant converter. The method comprises: establishing a mapping relationship between a dead time point of a modulation signal of the resonant converter and a count value of a carrier counter, so that the dead time point of the modulation signal corresponds to a target count value of the carrier counter; when a fault of the resonant converter is detected, blocking a driving signal of the resonant converter when a real-time count value of the carrier counter reaches the nearest target count value. The method can block the driving signal when the upper and lower tubes of the three-phase bridge arm are both in the off state, thereby avoiding voltage spikes caused by current mutation.

Description

Technical Field

[0001] This invention relates to the field of resonant converter technology, and in particular to a control method, device, controller, and resonant converter for a resonant converter. Background Technology

[0002] LLC (Inductor-Inductor-Capacitor) resonant converters, as a high-efficiency, high-power-density DC-DC conversion topology, play a crucial role in modern switching power supplies. By utilizing the soft-switching characteristics of the resonant cavity, they can achieve zero-voltage switching (ZVS) or zero-current switching (ZCS) of the switching transistors, significantly reducing switching losses and electromagnetic interference. This makes them widely used in medium-to-high power applications such as data centers, new energy power generation, and electric vehicle charging, and they are one of the core technologies for achieving high-efficiency power conversion.

[0003] In the actual operation of LLC resonant converter circuits, device short circuits are one of the common fault scenarios. Once a short circuit fault is detected, existing technologies usually trigger the overcurrent protection mechanism immediately, directly blocking the PWM (Pulse Width Modulation) drive signal of the corresponding phase to quickly disconnect the fault circuit and prevent the fault from escalating. However, the resonant cavity of an LLC resonant converter is composed of inductors, capacitors, and other components. During normal operation, the resonant current is in a periodic freewheeling state. When the drive signal is suddenly blocked, the resonant current of the corresponding phase loses its freewheeling path, generating an extremely high voltage reverse peak across the switching transistor. This voltage reverse peak often far exceeds the rated withstand voltage of the device, easily causing breakdown of the switching transistor, damage to core components such as resonant capacitors or inductors, further exacerbating the circuit fault and seriously affecting the operational reliability and service life of the LLC resonant converter.

[0004] Therefore, how to block the drive signal during a short-circuit fault while avoiding excessively high voltage back-peak impact has become a key technical problem that urgently needs to be solved in the current LLC resonant converter protection technology. Summary of the Invention

[0005] This invention provides a control method, device, controller, and resonant converter for a resonant converter, in order to solve the problem of voltage back-peak impact caused by the blocking drive after a resonant converter failure.

[0006] In a first aspect, embodiments of the present invention provide a control method for a resonant converter, comprising: Establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter; When a fault is detected in the resonant converter, the drive signal of the resonant converter is blocked when the real-time count value of the carrier counter reaches the nearest target count value.

[0007] Secondly, embodiments of the present invention provide a control device for a resonant converter, comprising: The mapping module is used to establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter. The drive blocking module is used to block the drive signal of the resonant converter when a fault is detected in the resonant converter and the real-time count value of the carrier counter reaches the nearest target count value.

[0008] Thirdly, embodiments of the present invention provide a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the control method for the resonant converter as described in any possible implementation of the first aspect above.

[0009] Fourthly, embodiments of the present invention provide a resonant converter, which includes the controller described in the third aspect above.

[0010] This invention provides a control method, apparatus, controller, and resonant converter for a resonant converter. The method first establishes a mapping between the dead time point of the modulation signal and the carrier count value, so that the dead time point of the modulation signal corresponds to a quantifiable target count value. When a fault occurs in the resonant converter, it is not immediately blocked, but rather the drive signal is blocked only when the carrier count value reaches its nearest target count value. Since the target count value corresponds to the dead time point, both the upper and lower transistors of the bridge arm are in the off state at this time, and the current naturally flows through the freewheeling diode, avoiding voltage spikes caused by sudden current changes. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1This is a schematic diagram illustrating the implementation flow of the control method for the resonant converter provided in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the correspondence between the modulation signal and the carrier signal of the resonant converter provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating another correspondence between the modulation signal and the carrier signal of the resonant converter provided in this embodiment of the invention; Figure 4 This is a schematic diagram of the control device for the resonant converter provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the controller provided in an embodiment of the present invention. Detailed Implementation

[0013] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0014] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0015] In existing resonant converter control strategies, when a short circuit or other fault occurs in the system, the protection circuit typically triggers an overcurrent protection mechanism immediately, directly blocking the PWM drive signal of the faulty bridge arm. The purpose of this immediate blocking strategy is to quickly disconnect the fault circuit and prevent the fault current from continuing to expand and causing device burnout. However, resonant converters differ from ordinary PWM converters in that their core feature lies in their resonant cavity network. The resonant circuit, composed of a resonant inductor, resonant capacitor, and transformer magnetizing inductance, stores a large amount of magnetic field energy during normal operation, and the resonant current is in a periodic freewheeling state.

[0016] When the controller suddenly blocks the drive signal, the corresponding bridge arm's switch is instantly turned off, and the resonant current instantly loses its freewheeling path through the switch. Since the current in an inductor cannot change abruptly, this forcibly interrupted resonant current induces an extremely high voltage spike across the switch. This voltage spike often far exceeds the switch's rated withstand voltage, easily leading to avalanche breakdown. Simultaneously, the high-voltage spike can also impact core components such as the resonant capacitor and transformer, causing insulation damage or capacitor explosion. This secondary damage not only further exacerbates the fault but also severely reduces the operational reliability and lifespan of the resonant converter.

[0017] To address the aforementioned technical problems, this invention proposes a control method for a resonant converter. This method pre-establishes a mapping relationship between the safe state of the bridge arm and the carrier counter, ensuring that the safe turn-off moment of the switching transistor corresponds to a quantifiable target count value. When a fault occurs, the drive is not immediately blocked; instead, based on this mapping relationship, the system waits for the safe turn-off moment of the switching transistor to be executed, thereby avoiding voltage spikes caused by sudden current changes.

[0018] For details, see Figure 1 The flowchart illustrating the implementation of the control method for the resonant converter provided in this embodiment of the invention is described in detail below: S101: Establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter.

[0019] In this embodiment, the carrier signal is a periodic reference signal used to generate the drive signal for the resonant converter. It can be a triangular wave or a sawtooth wave, and its frequency determines the switching frequency. The dead time point represents a specific moment in time during which the upper and lower switches of the bridge arm of the resonant converter are turned off simultaneously to prevent them from being turned on at the same time. At this moment, both the upper and lower switches of the bridge arm are in the off state. The carrier counter is a device that digitally quantizes and counts the period and phase of the carrier signal. The count value corresponds one-to-one with the phase of the carrier signal, representing the real-time timing position of the carrier. This embodiment establishes a correspondence between the dead time point of the modulation signal and the count value of the carrier counter, transforming the abstract dead time point into a quantifiable target count value, thereby facilitating the controller to capture the dead time point of the modulation signal.

[0020] Specifically, the resonant converter mentioned in this embodiment can be a single-phase resonant converter or a three-phase resonant converter. When the resonant converter is a single-phase resonant converter, it is only necessary to establish a mapping relationship between the dead time point of the modulation signal of the single-phase bridge arm and the target count value of the carrier counter. When the resonant converter fails and the count value of the carrier counter is detected to have reached the nearest target count value, the drive signals of the upper and lower switching transistors of the single-phase bridge arm are directly blocked.

[0021] When the resonant converter is a three-phase resonant converter, the specific implementation process of S101 includes: S201: Establish a mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of each carrier counter, so that the dead time point of the three-phase bridge arm corresponds to a target count value of each carrier counter.

[0022] Specifically, in a three-phase resonant converter, the three-phase carrier signals can adopt the aforementioned synchronous design. Under synchronous carrier, the three-phase carrier signals use the same carrier counter. The three-phase modulated wave is compared with the carrier to generate the drive signal. The duty cycle and switching sequence of the three-phase drive signal are strictly symmetrical, which can directly ensure the amplitude and phase symmetry of the three-phase output voltage / current.

[0023] To avoid the reverse peak impact during a three-phase resonant converter fault blockade, this embodiment establishes a mapping relationship between the dead time points of the three-phase modulation signals and the count values ​​of the corresponding carrier counters for each of the three-phase carrier signals, referring to... Figure 2 , Figure 2 This diagram illustrates the correspondence between modulation signals and carrier signals in a resonant converter. In the lower pulse signals, PWM1A and PWM1B are the modulation signals for the upper and lower transistors of the first phase bridge arm, PWM2A and PWM2B are the modulation signals for the upper and lower transistors of the second phase bridge arm, and PWM3A and PWM3B are the modulation signals for the upper and lower transistors of the third phase bridge arm. In the upper triangular carrier signal, CPMA is the carrier count value corresponding to the rising edge dead time point, and CPMB is the carrier count value corresponding to the falling edge dead time point. According to... Figure 2 It can be seen that, based on the correspondence between the three-phase modulation signal and the three-phase carrier signal, the dead time point of the three-phase modulation signal can be found to correspond to the count value of each carrier counter, thus establishing the mapping relationship.

[0024] Specifically, after determining the target count value of the carrier counter corresponding to the dead time point of the modulation signal of the first phase bridge arm PWM1A and PWM1B, since the carrier counters of the three phase carrier signals are synchronized, the controller can obtain the target count value corresponding to the dead time point of the other two phase bridge arms based on the phase difference of the three-phase modulation signals and the target count value of the carrier counter corresponding to the dead time point of the first phase bridge arm.

[0025] S102: When a fault is detected in the resonant converter, the drive signal of the resonant converter is blocked when the real-time count value of the carrier counter reaches the nearest target count value.

[0026] In this embodiment, taking a three-phase resonant converter as an example, when the controller detects abnormal conditions such as short circuit or overcurrent in the resonant converter through sensors or monitoring circuits, it blocks the drive signal of the corresponding phase bridge arm when the real-time count value of the carrier counter of the phase is equal to the first target count value it reaches.

[0027] As can be seen from the above embodiments, this embodiment first establishes a mapping between the dead time point of the modulation signal and the carrier count value, so that the dead time point of the modulation signal corresponds to a quantifiable target count value. When the resonant converter fails, it is not immediately blocked, but waits for the carrier count value to reach its nearest target count value before blocking the drive signal. Since the target count value corresponds to the dead time point, both the upper and lower transistors of the bridge arm are in the off state at this time, and the current naturally flows through the freewheeling diode, avoiding voltage spikes caused by sudden current changes.

[0028] In addition, this application selects the dead time point of each phase modulation signal as the timing for turning off the drive signal. Compared with the zero-crossing point of the input AC voltage, since the power frequency period corresponding to the input AC voltage is much larger than the switching period of the PWM modulation signal, when a fault occurs, the controller can complete the drive blocking at the dead time point in the microsecond range without waiting for the zero-crossing point of the input voltage in the millisecond range, which greatly improves the protection response speed.

[0029] In one possible implementation, when the resonant converter includes three-phase bridge arms, prior to S101, the method provided in this embodiment further includes: The phases of the three-phase carrier signals of the resonant converter are configured such that they are successively differed by a first phase angle.

[0030] In this embodiment, reference Figure 2 When three-phase carriers are synchronized, it means that the carrier signals of each phase are counted using the same carrier counter. However, for three-phase modulated waves, to achieve electrical angular symmetry, the phases of the modulated waves are typically 120° apart, causing the dead time points of each phase to be uniformly offset on the time axis, with an interval of 1 / 3 of a switching cycle. Assume that the dead time point of phase A occurs at absolute time... t A Then the dead time points of phase B and phase C occur respectively. and Where T is the carrier period. Due to carrier synchronization, the carrier counter's count value changes monotonically with time, such as increasing in a sawtooth wave or changing symmetrically in a triangular wave, and the count value within each period corresponds one-to-one with time. Therefore, the count value at different times must be different. Thus, we can conclude that... t A , , The count values ​​corresponding to the three time points are not equal, meaning that the target count values ​​mapped to the respective carrier counters at the dead time points of the three phases will necessarily be different.

[0031] In this embodiment, to ensure that the target count values ​​of the three-phase carrier counters are at the same time point and to simplify the processing, the phases of the three-phase carrier signals are sequentially staggered by a first phase angle, so that the carrier counters of each phase are staggered by a fixed phase difference on the time axis. (Reference) Figure 3At this point, although the counting process of each phase counter is independent and the start time is different, the dead time point of each phase can be uniformly set at the same relative position in its own carrier cycle, such as the counter zeroing point (count value 0). Assuming that phase A carrier starts counting from time 0, its dead time point is set at the moment the counter is 0, that is... t=kT (k is an integer). The B-phase carrier lags behind the first phase angle. Corresponding time delay Therefore, the moment when the B-phase counter reaches 0 occurs If the dead time of phase B is also set when its counter reaches 0, then the dead time of phase B will be exactly [time value missing]. Similarly, the dead time of phase C is... Therefore, by staggering the carrier phases, the target count values ​​mapped to the respective carrier counters at the three-phase dead time points can be made exactly the same, thereby simplifying the control logic.

[0032] As can be seen from the above embodiments, this embodiment is based on phase difference configuration, and the three-phase dead zone points are evenly distributed on the time axis, which can ensure that each phase can find a safe blocking point in the shortest time at any fault moment, thereby protecting the main circuit while effectively preventing secondary damage and improving the fault survivability of the converter.

[0033] In one possible implementation, the specific process of establishing the mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of the carrier counter in S201 above includes: Establish a mapping relationship between the rising edge dead time of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of the carrier counter.

[0034] In this embodiment, the rising edge dead time point is the starting moment of the dead time set before the bridge arm modulation signal of the resonant converter jumps from low level to high level (rising edge) to prevent the upper and lower transistors from shoot-through. At this moment, the modulation signal is at an invalid level, and both the upper and lower switches of the bridge arm are turned off.

[0035] Specifically, the rising edge dead time is associated with the target count value of the carrier counter. When the controller detects that the count value of the carrier counter for each phase has reached the target count value, it blocks the drive signal of the corresponding phase. This target count value can be any value preset by the user, selected from 0 to the maximum carrier count value.

[0036] As can be seen from the above embodiments, this embodiment specifically limits the mapping object of the dead time point to the rising edge dead time point of the modulation signal. The dead time sequence at this moment is controlled by the modulation wave and the carrier, and has higher stability and predictability. Using it as the mapping object can make the mapping relationship between the dead time point and the carrier counter count value more accurate, reduce the mapping deviation caused by the instability of the dead time, and improve the accuracy of the target count value in representing the actual dead time point. At the same time, the position of the rising edge dead time point within the modulation signal period is relatively fixed. The mapping relationship established based on this time point will not change significantly due to small adjustments in the duty cycle and frequency of the modulation wave, thereby improving the stability and robustness of the mapping relationship.

[0037] In one possible implementation, the control method for the resonant converter provided in this embodiment further includes: According to a preset time interval, the hardware capture unit of the PWM module captures the real-time count value of the carrier counter of each phase arm when the dead time point actually occurs, and uses it as the actual count value. For any phase, if the difference between the actual count value and the target count value of the phase is greater than the preset count difference, then the target count value corresponding to the dead time point of the phase is adjusted to the real-time count value.

[0038] Specifically, during normal system operation, the dead time is automatically generated by the hardware PWM module based on the comparison value, and the controller does not need to monitor it. However, the actual occurrence time of the dead time may deviate from the configured target count value due to the following reasons: 1. Temperature variation: The turn-on / turn-off delay of the drive circuit and switching transistors changes with temperature, causing the actual dead zone insertion point to shift.

[0039] 2. Voltage fluctuations: Changes in bus voltage affect switching speed, which in turn changes the actual position of the dead zone.

[0040] 3. Device aging: The aging of switching transistors and driver chips leads to changes in delay characteristics.

[0041] 4. Parasitic parameters of PCB (Printed Circuit Board): Wiring inductance and capacitance affect signal transmission delay.

[0042] These factors can cause a fixed or slowly varying deviation between the actual dead time corresponding to the preset target count value and the ideal dead time. Therefore, to ensure the accuracy of dead time point capture, this embodiment uses a hardware capture unit to monitor the actual dead time at preset time intervals. The preset time interval can be one week, one month, or one year.

[0043] Specifically, the hardware capture unit is a dedicated hardware integrated into the controller or PWM module. It can instantly freeze and store the current carrier counter value when an external event (such as a dead time point) is triggered, and has extremely high time accuracy.

[0044] Before implementing this method, the input capture channel of the PWM module needs to be configured to capture events at either the rising edge or falling edge dead time. For example, capture is triggered when the upper transistor is off and the lower transistor is not yet on, at the start of the dead time. The controller reads the actual dead time captured in the capture interrupt service routine, records it as the actual count value, and compares it with the currently stored target count value. If the deviation exceeds a preset count difference, the target count value is updated to the actual count value.

[0045] As can be seen from the above embodiments, this embodiment captures the actual dead zone occurrence time in real time through hardware and dynamically updates the target count value with this actual count value. This ensures that the target count value always remains consistent with the true dead zone position, and regardless of environmental changes, the blocking action during a fault always falls within the true safe moment, avoiding false blocking or delayed blocking caused by drift.

[0046] In one possible implementation, the target count value includes a first pre-designed value and a second pre-designed value; the specific implementation process of S201 includes: Establish a mapping relationship between the dead time points of the modulation signals of the three-phase bridge arms of the resonant converter and the count values ​​of the carrier counters, such that the rising edge dead time points of the three-phase bridge arms correspond to the first pre-designed values ​​of their respective carrier counters, and the falling edge dead time points of the three-phase bridge arms correspond to the second pre-designed values ​​of their respective carrier counters.

[0047] In this embodiment, the falling edge dead time point is the start time of the dead time set when the falling edge of the bridge arm modulation signal of the resonant converter arrives, in order to prevent the upper and lower switches from shoot-through. At this time, the upper and lower switches of the bridge arm are also in the off state.

[0048] Specifically, this embodiment expands the target count value into a first pre-designed value and a second pre-designed value, establishing a one-to-one mapping relationship with the rising edge dead time point and falling edge dead time point of the modulation signal of the three-phase bridge arm, respectively. That is, each phase bridge arm has two target count values ​​bound to the dead time point within one carrier cycle. After fault detection, the target count value closer to the real-time count value of the carrier counter can be selected to perform the blocking action. This method allows for more flexible triggering of fault blocking, shortening the maximum waiting time from one carrier cycle to half a carrier cycle, improving the response speed of fault protection, while retaining the advantage of dead-time blocking. It ensures that regardless of which target count value is selected, blocking can be performed in the safe off state of the bridge arm. Compared with a single dead-time point mapping, it achieves a dual improvement in fault protection response speed and protection reliability, significantly improving the response speed of fault protection, effectively reducing the accumulation of resonant current during the fault duration, and reducing the risk of fault expansion.

[0049] Secondly, the dual mapping of the two dead time points provides more options for triggering fault blocking. Even if the mapping relationship of one dead time point deviates slightly due to factors such as electromagnetic interference or sampling errors, precise blocking can still be achieved through the other dead time point, thereby improving the fault tolerance of the protection strategy. Simultaneously, both the rising and falling edge dead time points are safe turn-off moments for the upper and lower switches of the bridge arm. Regardless of which time point is selected for blocking, the resonant current can be guaranteed to naturally flow through the freewheeling diode without generating voltage reverse peaks. While improving response speed, this fully retains the core effect of the original protection strategy in preventing secondary damage.

[0050] For example, the three-phase carrier signals are configured with a first phase angle differing by 120° sequentially: phase A 0°, phase B 120°, and phase C 240°. A carrier counter increments cyclically, with count values ​​from 0 to 359 corresponding to the 360° phase of the carrier. A mapping relationship is established between the dual dead-time points and the carrier counter, mapping the rising edge dead-time point of phase A to a first pre-designed value of 0, and the falling edge dead-time point to a second pre-designed value of 180. When a short-circuit fault is detected, if the real-time count value of the carrier counter for phase A is 100, then phase A selects the closer second pre-designed value of 180; if the real-time count value of the carrier counter for phase A is 300, then the closer first pre-designed value of 0 is selected. The drive is blocked when the real-time count value of phase A reaches the corresponding point. It is evident that this method can effectively shorten the waiting time for drive blocking, thereby preventing further escalation of the fault.

[0051] In one possible implementation, the first phase angle is 120 degrees; the target count values ​​for all three phase arms are 0.

[0052] In this embodiment, when the first phase angle is 120 degrees, if the initial phase of phase A is 0°, then phase B is 120° and phase C is 240°. This embodiment explicitly sets the phases of the three-phase carrier signals to differ by 120° sequentially. 120° is the standard phase difference of a three-phase power electronic topology, which matches the 120° phase difference of the three-phase modulated wave. This allows the three-phase carrier signals to be completely symmetrically distributed within the 360° carrier cycle, ensuring that the switching sequence of the three-phase bridge arms is uniformly and equally spaced on the time axis. This configuration not only ensures that the turn-on and turn-off intervals of each phase switch are equal, balancing the current stress and switching losses of the three-phase bridge arms and avoiding bus current spikes caused by concentrated three-phase switching actions, but also simplifies the mapping derivation logic between the dead time point and the carrier counter, making the target count values ​​of the three phases equal. This provides a mathematical basis for the standardized configuration of the three-phase target count values ​​and is compatible with existing three-phase power electronic control chips and drive circuits, reducing the difficulty of engineering implementation.

[0053] Furthermore, based on the first phase angle of 120°, this embodiment sets the target count value to 0, that is, the dead time points of the three phase arms A, B, and C are all mapped to the count value of 0 of their respective carrier counters. This count value is a standardized target count value common to the three phases, which is the starting point for the carrier counter to increment, the ending point for the carrier counter to decrement, or the reference point for cyclic counting.

[0054] Specifically, this embodiment unifies the target count value to 0, ensuring that the fault blocking trigger benchmark of the three-phase bridge arms remains consistent. This eliminates the need to set different target count values ​​for each phase, significantly simplifying the controller's software control logic, reducing programming workload and error probability, and making the fault blocking judgment conditions simpler, thus improving the controller's operational efficiency. Secondly, the zero point of the carrier counter, being the start or cycle node of the counting period, is the easiest and most stable count value to detect. Compared to other count values, the zero-point detection circuit design is simpler, with higher detection accuracy, effectively reducing blocking timing errors caused by count value detection deviations and ensuring that the fault blocking action is always executed precisely at the dead time point. Simultaneously, the unified zero-point target count value allows for a high degree of coordination between the phase configuration of the three-phase carrier signals and the mapping of the dead time point. Under a carrier configuration with a 120-degree phase difference, the dead time point of each phase can accurately align with the zero point of its own carrier counter, ensuring the accuracy and stability of the mapping relationship.

[0055] In one possible implementation, the first phase angle can also be 60°, 90° or 180°.

[0056] In one possible implementation, if multiple resonant converters are connected in parallel, the three-phase carriers of each module are phase-shifted between groups based on 120°, for example, 0° / 120° / 240° for module 1 and 30° / 150° / 270° for module 2, thereby reducing the system input / output current ripple.

[0057] In one possible implementation, the target count value can also be any count value from 0 to the maximum count value.

[0058] In one possible implementation, the modulation signal includes a PWM signal; the specific implementation process of S102 includes: When the real-time count value of the carrier counter of each phase bridge arm reaches its corresponding nearest target count value, the PWM signals of the upper and lower switching transistors of the corresponding phase bridge arm are both set to invalid level.

[0059] In this embodiment, the PWM signal is a modulation signal that adjusts the output voltage / current by changing the pulse width, and it is a signal that controls the switching transistor to turn on / off.

[0060] The invalid level is the PWM signal level that keeps the switching transistor off. Its specific level value is determined by the type of switching transistor; for example, a low level is usually an invalid level for an N-type MOSFET, while a high level is usually an invalid level for a P-type MOSFET.

[0061] In this embodiment, the method of blocking the drive signal is specifically limited to setting the PWM signals of both the upper and lower switches of the bridge arm to an invalid level. When the controller detects a fault in the resonant converter, it sets the PWM signals of both the upper and lower switches to an invalid level, which can directly cut off the drive signal of the switch and ensure that the upper and lower switches of the bridge arm are in the off state at the same time. This completely avoids the bridge arm shoot-through problem caused by a single switch still having a drive signal, and ensures the safety state of the bridge arm from the control signal level.

[0062] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0063] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0064] Figure 4 A schematic diagram of the control device for a resonant converter provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below: like Figure 4 As shown, the control device 100 of the resonant converter includes: The mapping module 110 is used to establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter. The drive blocking module 120 is used to block the drive signal of the resonant converter when a fault is detected in the resonant converter and the real-time count value of the carrier counter reaches the nearest target count value.

[0065] In one possible implementation, the mapping module 110 is specifically used for: Establish a mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of each carrier counter, so that the dead time point of the three-phase bridge arm corresponds to a target count value of each carrier counter.

[0066] In one possible implementation, the device 100 further includes a phase difference configuration module for: Before establishing the mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of their respective carrier counters, the phases of the three-phase carrier signals of the resonant converter are configured to be sequentially differing by a first phase angle.

[0067] In one possible implementation, the target count value includes a first pre-designed value and a second pre-designed value; the mapping module 110 is specifically used for: Establish a mapping relationship between the dead time points of the modulation signals of the three-phase bridge arms of the resonant converter and the count values ​​of the carrier counters, such that the rising edge dead time points of the three-phase bridge arms correspond to the first pre-designed values ​​of their respective carrier counters, and the falling edge dead time points of the three-phase bridge arms correspond to the second pre-designed values ​​of their respective carrier counters.

[0068] In one possible implementation, the first phase angle is 120 degrees; the target count values ​​for all three phase arms are 0.

[0069] In one possible implementation, the modulation signal includes a PWM signal; the drive blocking module 120 is specifically used for: When the real-time count value of the carrier counter of each phase bridge arm reaches its corresponding nearest target count value, the PWM signals of the upper and lower switching transistors of the corresponding phase bridge arm are both set to invalid level.

[0070] Figure 5 This is a schematic diagram of the controller provided in an embodiment of the present invention. Figure 5 As shown, the controller 5 in this embodiment includes a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, it implements the steps in the control method embodiments of the various resonant converters described above, for example... Figure 1Steps S101 to S102 are shown. Alternatively, when the processor 50 executes the computer program 52, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 4 The functions of modules 110 to 120 are shown.

[0071] For example, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 52 in the controller 5.

[0072] The controller 5 can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The controller 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that... Figure 5 This is merely an example of controller 5 and does not constitute a limitation on controller 5. It may include more or fewer components than shown, or combine certain components, or different components. For example, the controller may also include input / output devices, network access devices, buses, etc.

[0073] The processor 50 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0074] The memory 51 can be an internal storage unit of the controller 5, such as a hard disk or memory of the controller 5. The memory 51 can also be an external storage device of the controller 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the controller 5. Furthermore, the memory 51 can include both internal storage units and external storage devices of the controller 5. The memory 51 is used to store the computer program and other programs and data required by the controller. The memory 51 can also be used to temporarily store data that has been output or will be output.

[0075] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments 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 unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0076] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0077] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0078] In the embodiments provided by this invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0079] 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 this embodiment according to actual needs.

[0080] 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 unit can be implemented in hardware or as a software functional unit.

[0081] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the control methods for the various resonant converters described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0082] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for a resonant converter, characterized in that, include: Establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter; When a fault is detected in the resonant converter, the drive signal of the resonant converter is blocked when the real-time count value of the carrier counter reaches the nearest target count value.

2. The control method for the resonant converter according to claim 1, characterized in that, The resonant converter includes a three-phase bridge arm; The establishment of the mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, such that the dead time point of the modulation signal corresponds to the target count value of the carrier counter, includes: Establish a mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of each carrier counter, so that the dead time point of the three-phase bridge arm corresponds to a target count value of each carrier counter.

3. The control method for the resonant converter according to claim 2, characterized in that, Before establishing the mapping relationship between the dead time points of the modulation signals of the three-phase bridge arms of the resonant converter and the count values ​​of their respective carrier counters, the method further includes: The phases of the three-phase carrier signals of the resonant converter are configured such that they are successively differed by a first phase angle.

4. The control method for the resonant converter according to claim 2, characterized in that, The mapping relationship between the dead time points of the modulation signals of the three-phase bridge arms of the resonant converter and the count values ​​of their respective carrier counters includes: Establish a mapping relationship between the rising edge dead time of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of the carrier counter.

5. The control method for the resonant converter according to claim 2, characterized in that, The target count value includes a first pre-designed value and a second pre-designed value; The process of establishing a mapping relationship between the dead time point of the modulation signal of the three-phase bridge arm of the resonant converter and the count value of the carrier counter, such that the dead time point of the modulation signal corresponds to the target count value of the carrier counter, includes: Establish a mapping relationship between the dead time points of the modulation signals of the three-phase bridge arms of the resonant converter and the count values ​​of the carrier counters, such that the rising edge dead time points of the three-phase bridge arms correspond to the first pre-designed values ​​of their respective carrier counters, and the falling edge dead time points of the three-phase bridge arms correspond to the second pre-designed values ​​of their respective carrier counters.

6. The control method for the resonant converter according to claim 3, characterized in that, The first phase angle is 120 degrees; the target count values ​​of the three-phase bridge arms are all 0.

7. The control method for the resonant converter according to any one of claims 2 to 6, characterized in that, The modulation signal includes a PWM signal; The step of blocking the drive signal of the resonant converter when the real-time count value of the carrier counter reaches the nearest target count value includes: When the real-time count value of the carrier counter of each phase bridge arm reaches its corresponding nearest target count value, the PWM signals of the upper and lower switching transistors of the corresponding phase bridge arm are both set to invalid level.

8. A control device for a resonant converter, characterized in that, include: The mapping module is used to establish a mapping relationship between the dead time point of the modulation signal of the resonant converter and the count value of the carrier counter, so that the dead time point of the modulation signal corresponds to the target count value of the carrier counter. The drive blocking module is used to block the drive signal of the resonant converter when a fault is detected in the resonant converter and the real-time count value of the carrier counter reaches the nearest target count value.

9. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the control method for the resonant converter as described in any one of claims 1 to 7.

10. A resonant converter, characterized in that, include: The controller as described in claim 9.

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