4995 results about "Secondary side" patented technology

The invention discloses a control circuit of an electronic load, the electronic load and a power supply test system. The circuit comprises an MCU; the signal output end of the MCU is connected with the input end of the DAC module; the closed-loop control circuit comprises a first error amplifier, a mutual inductor, an MOS (Metal Oxide Semiconductor) tube, a current sampling resistor and a power supply end VBUS; a mutual inductor is arranged between a first error amplifier and an MOS tube of the closed-loop control circuit, a power supply end VBUS is connected with a drain electrode of the MOS tube through a primary side of the mutual inductor, a first secondary side of the mutual inductor feeds back an input signal of the first error amplifier, and a second secondary side of the mutual inductor feeds back a driving signal of the first error amplifier to the MOS tube. According to the invention, the dynamic response speed when the electronic load pulls the high-frequency current can be improved, and the test requirements of high precision and high dynamic response are met.

A system includes: an AC-DC converter; and a DC-DC converter, the DC-DC converter including: a first high voltage buck-boost converter having a secondary side connectable to a first high voltage battery; a second high voltage buck-boost converter having a secondary side connectable to a second high voltage battery; a first low voltage buck-boost converter having a secondary side connectable to a first low voltage battery; a second low voltage buck-boost converter having a secondary side connectable to a second low voltage battery; and one or more transformers having a primary side connected to the AC-DC converter and a secondary side connected to each of a primary side of the first high voltage buck-boost converter, a primary side of the second high voltage buck-boost converter, a primary side of the first low voltage buck-boost converter, and a primary side of the second low voltage buck-boost converter.

The invention provides a mutual inductor fault diagnosis method based on multi-sensor data fusion and transfer learning, and the method comprises the following steps: S1, installing a plurality of high-precision sensors on the secondary side of a voltage transformer to be subjected to fault diagnosis based on the voltage transformer to be subjected to fault diagnosis; s2, on the basis of the step S1, performing data acquisition and processing on data acquired by various high-precision sensors through a DHDAS dynamic signal acquisition instrument; and S3, based on the step S2, carrying out fault diagnosis on the voltage transformer through a PC (Personal Computer) carrying acquisition analysis software on the DHDAS dynamic signal acquisition instrument. According to the method, multi-mode signals such as voltage, current and temperature are synchronously collected, time-frequency domain features are extracted through continuous wavelet transform, the dynamic characteristics of interlayer short circuit faults can be more comprehensively represented, meanwhile, by combining transfer learning and a deep neural network, the intelligent diagnosis model can remarkably improve the classification performance under the condition that sample data is small, and the classification efficiency is improved. And the limitation of a single-mode signal diagnosis method is effectively overcome.

The invention relates to the technical field of active damping control, and discloses a bidirectional DC-DC power supply active damping control system and method, and the system comprises a front-end AC input rectification module, an LLC resonant circuit, and a Buck converter module: the front-end AC input rectification module is used for converting an AC input voltage into a DC voltage; the LLC resonance circuit is used for inverting the rectified direct current voltage into alternating current with a set frequency and transmitting the alternating current to a secondary side through a transformer; and the Buck converter module is used for rectifying an alternating current signal and adjusting the alternating current signal into a required direct current output voltage, and further comprises an LC filter and an active damping control module. By adopting the active damping control method, the resonance peak caused by the LC filter can be effectively suppressed without additionally adding a physical resistor, so that the fluctuation of the output voltage is limited. According to the control strategy, the problems of power loss and heating caused by a traditional passive damping method are avoided, and the energy efficiency of the system is remarkably improved.

A multi-phase LLC resonant converter circuit (10) includes: first to third LLC resonant converters each including a series circuit (S1 to S3) of a first switch and a second switch that are connected in parallel to a DC power supply, a high-frequency transformer (T1 to T3) including a primary-side winding and a secondary-side winding, a resonant circuit including a resonant reactor (Lr1 to Lr3) connected between a connection point of the first switch and the second switch and one end of the primary-side winding, a resonant capacitor (Cr1 to Cr3) in which one end is connected to the other end of the primary-side winding, and a divided resonant capacitor (Cn1 to Cn3) in which one end is connected to a connection point of the primary-side winding and the resonant capacitor; a first neutral line (N1) that connects the other end of the resonant capacitor; a neutral line reactor (Ln) connected between the first neutral line and a power supply line of the DC power supply; and a second neutral line (N2) that connects the other end of the divided resonant capacitor.

An automotive power system includes an AC / DC power converter, a transformer, a switching bridge connected between the AC / DC power converter and transformer, and a switch bank connected with a secondary side of the transformer. The switch bank connects the secondary side between an electric machine and another switching bridge such that the electric machine, first switching bridge, transformer, and second switching bridge form an isolated DC / DC power converter. The system further includes one or more switches configured to directly connect the traction battery between the AC / DC power converter and second switching bridge.

The invention discloses a variable-frequency reconfigurable wireless electric energy transmission system and a parameter design method, and relates to a wireless electric energy transmission system and a parameter design method. The invention aims to solve the problems that the existing wireless power transmission technology is difficult to maintain approximately constant power transmission in the face of wider coupling coefficient fluctuation, and the system control complexity is higher at the same time. The system comprises a full-bridge inverter circuit, a primary side compensation network, a coupling coil, a secondary side compensation network and a rectification filter circuit. The input end of the full-bridge inverter circuit is connected with a direct-current voltage source UD, the output end of the full-bridge inverter circuit is connected with the input end of the primary side compensation network, the output end of the primary side compensation network is connected with the primary side input end of the coupling coil, and the secondary side output end of the coupling coil is connected with the input end of the secondary side compensation network. The output end of the secondary side compensation network is connected with the input end of the rectification filter circuit; the output end of the rectification filter circuit is connected with a battery load Ro. The invention belongs to the technical field of wireless power transmission.

The invention provides a two-stage converter topological structure and a control method. The two-stage converter topological structure comprises a power supply, a DAB circuit, a Boost circuit, an input capacitor and a load resistor, a power supply voltage, an actual voltage of a second multiplexing capacitor and an actual output voltage of a DAB circuit are collected and input into a controller; the controller calculates the power supply voltage, the actual voltage of the second multiplexing capacitor and the actual output voltage of the DAB circuit to obtain a PWM driving signal of each switching tube; the turn-on time difference of the primary side switch tube and the secondary side switch tube in the DAB circuit is controlled through the PWM driving signal of each switch tube, and the output power of the two-stage converter is adjusted; the turn-on time of each switch tube in the Boost circuit is controlled through the PWM driving signal of each switch tube, and the voltage gain of the two-stage converter is adjusted; and the electric energy conversion efficiency is improved while electric isolation is realized.

The invention discloses a zero-sequence pilot-frequency excitation method for a double-circuit line in an incomplete power failure environment, which comprises the following steps of: applying zero-sequence pilot-frequency signal excitation on a power failure line by using a pilot-frequency power supply as an excitation signal source of a zero-sequence network of the double-circuit line, different-frequency induced current and voltage are measured at secondary sides of a current transformer and a voltage transformer at two sides of the operation line, and different-frequency zero-sequence voltage and different-frequency zero-sequence current in the double-circuit line zero-sequence network are obtained; simultaneously solving a zero-sequence network equation, and calculating mutual impedance between double circuits; performing frequency conversion to obtain the power frequency mutual impedance of the line; and finally, carrying out simulation verification by constructing a non-full-stop double-circuit line zero-sequence mutual inductance impedance measurement system. According to the method, the multi-path coupling caused by the existing power frequency interference method and the accuracy problem caused by the signal measurement error of the zero sequence increment method are solved, the test calculation can be accurately completed under the complex interference working condition, and the safety risk caused by the single-phase reclosing operation is avoided.

The invention provides a circulation power optimization method and system for a three-phase dual-active bridge, and relates to the field of power electronics, the method comprises the following steps: determining an optimal backflow modulation strategy set corresponding to a hybrid modulation group, the hybrid modulation group comprising triangular wave modulation, trapezoidal modulation, synchronous modulation and extended phase shift modulation, the optimal backflow modulation strategy set corresponding to the hybrid modulation group comprises modulation modes and degree-of-freedom relationships corresponding to different transmission power per unit value ranges in different voltage conversion ratio ranges; determining a degree of freedom and power relationship set corresponding to the hybrid modulation group, wherein the relationship set comprises a relationship between the degree of freedom and power of different transmission power per unit values corresponding to each mode; the phase shift angle, the primary side duty ratio and the secondary side duty ratio are determined by combining the real-time voltage conversion ratio and the real-time virtual power per unit value, operation of the three-phase dual-active bridge is controlled, and the method has the advantages of reducing complexity and improving portability and efficiency.

The invention discloses an anti-direct-current component nanocrystalline current transformer and a using method thereof. The anti-direct-current component nanocrystalline current transformer comprises a current transformer body, and a magnetic core hole penetrating front and back is formed in the middle of the front side of the current transformer body. The device is provided with a secondary side open circuit detection and protection mechanism, so that imbalance of a magnetic field in the mutual inductor caused by disconnection of a secondary loop is effectively prevented, iron core magnetic flux saturation and potential high electromotive force generation are avoided, the safety of the mutual inductor and peripheral equipment is protected, the risk of power system faults such as fire disasters or short circuits is reduced, and meanwhile, the safety of the mutual inductor is improved. A live wire centering fixing mechanism is arranged, so that the stable centering position of a wire in a magnetic core hole of the mutual inductor is ensured, magnetic field distribution is optimized, the magnetic leakage phenomenon is reduced, the accuracy and stability of current measurement are remarkably improved, meanwhile, measurement fluctuation caused by wire shaking is reduced, and the measurement precision is improved. And more accurate data support is provided for harmonic analysis, fault detection and electric energy quality monitoring of a power system.

A system includes: an alternating current (AC) to direct current (DC) converter (AC-DC converter), the AC-DC converter connectable to a line voltage; and a DC to DC converter (DC-DC converter) connected to the AC-DC converter, the DC-DC converter including: a high voltage buck-boost converter having a secondary side connectable to a high voltage battery; a low voltage buck-boost converter having a secondary side connectable to a low voltage battery; and one or more transformers having a primary side connected to the AC-DC converter, a secondary side connected to a primary side of the high voltage buck-boost converter, and a tertiary side connected to a primary side of the low voltage buck-boost converter.

The invention discloses an optimal control method for a single-phase high-frequency chain AC-DC non-electrolytic capacitor converter, and belongs to the technical field of power electronics. In order to realize power factor correction and soft switching without a closed-loop control circuit, the circuit comprises a converter and a controller, and the converter and the controller are connected through a signal; the controller collects a signal of the converter as a feedback signal, and generates a driving pulse signal of the converter in an SPWM mode. A phase shift control method and a dead zone self-adaptive control method are adopted to control a first series switch tube, a second series switch tube, a third series switch tube and a fourth series switch tube in a primary side matrix converter and a secondary side first switch tube and a secondary side second switch tube of a secondary side rectifier; and the frequency and the pulse width of the secondary-side third switch tube and the secondary-side fourth switch tube are optimally controlled. The driving pulse signal of the pre-stage matrix converter is generated, a direct-current link energy storage capacitor of a traditional two-stage rectifying circuit is eliminated, the size is reduced, and the hardware cost is saved.

The invention relates to a medium-voltage expansion ice melting device and an ice melting expansion system. The medium-voltage expansion ice melting device comprises an ice melting transformer and a reactive compensation unit, the primary side of the ice-melting transformer is electrically connected with the power supply end of the medium-voltage power supply, and the secondary side of the ice-melting transformer and the input end of the reactive compensation unit are electrically connected with the ice-melting output end; wherein the ice melting transformer is a double-winding ice melting transformer of which the primary side is subjected to on-load voltage regulation and the secondary side is subjected to no-load gear regulation, and the medium-voltage power supply comprises a medium-voltage emergency power supply vehicle or a power grid; the deicing transformer is used for adjusting the alternating current of the medium-voltage power supply into the adjustable alternating current of the line section to be deiced, and the reactive compensation unit is used for regulating and controlling the reactive compensation current and the reactive compensation power. According to the technical scheme of the invention, the medium-voltage emergency generator car can be fully utilized to quickly expand the ice melting function of the medium-voltage emergency generator car, and meanwhile, the ice melting technical equipment of power grid power supply can be considered, and the economy of distribution network ice melting is improved.

The invention discloses a DAB-based two-stage DC-AC converter system, which is composed of a dual-active full-bridge DC-DC converter and a single-phase grid-connected inverter, and is characterized in that the dual-active full-bridge DC-DC converter is formed by connecting a primary side full bridge and a secondary side full bridge through a high-frequency transformer HFL and a resonance circuit composed of Cr and Lr; the single-phase grid-connected inverter comprises an inverter full bridge composed of switch tubes K1-K4 and an LCL type grid-connected filter circuit composed of inductors L1 and L2 and a capacitor C; the invention further discloses a secondary ripple suppression method and a control strategy, the pulse power of double frequency multiplication in the direct-current bus capacitor is transferred to the LC power decoupling branch through the LC passive branch connected to the middle point of the secondary side of the double active bridge, so that power decoupling is achieved, and the secondary ripple suppression in the direct-current bus voltage keeps the bus voltage stable.

The present disclosure provides a signal delay setting circuit, an isolation integrated circuit and a power conversion circuitry. The isolation integrated circuit includes a primary side circuit, an isolation circuit and a secondary side circuit. The primary side circuit generates a primary side signal according to a first input signal and a second input signal. The isolation circuit converts the primary side signal into a secondary side signal. The secondary side circuit receives the secondary side signal through the isolation circuit, to generate an output signal. The signal delay setting circuit is coupled to the secondary side circuit, calculates a delay time according to a voltage difference between an alternative terminal and a secondary side ground terminal of the isolation integrated circuit, and delays the secondary side signal according to the delay time, to control the duty ratio of the output signal.

The invention relates to the technical field of equipment control, in particular to a self-adaptive switching method and system of a current transformer. The method comprises the following steps: collecting primary side parameters and secondary side parameters of a current transformer to obtain primary side collection parameters of the current transformer and secondary side collection parameters of the current transformer; performing current transformer state segmentation initialization according to the current transformer primary side acquisition parameters and the current transformer secondary side acquisition parameters so as to generate a current transformer operation state classification result; switching result judgment is conducted on the current transformers according to the current transformer operation state classification result, and when the current transformer operation state classification result is a current transformer critical state section, parallel buffering is conducted on the current transformers, and critical current transformer switching data are generated. According to the invention, through accurate state classification, a dynamic switching mechanism, time sequence optimization and visual display, the switching sensitivity and stability of the current transformer are improved.

The invention relates to a method for determining the rotor current of a separately excited synchronous machine (FSM), comprising a stator and a rotor with an excitation winding. Initially, an excitation supply voltage is connected via a controlled bridge circuit to terminals A and B of an inductive transformer. On the secondary side, this transformer is connected to the excitation winding of the FSM via a rectifier. The controlled bridge circuit can be regulated via switching parameters using a control unit. Subsequently, the primary current of the excitation winding of the FSM is sampled at terminals A and B. Then, an evaluation time for the sampled primary current is determined, and the primary current is evaluated at that time. The evaluated primary current is then converted to the rotor current. Finally, the rotor current at the evaluation time is output.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The invention discloses a fault diagnosis method and system for a metering error of a voltage transformer, and relates to the technical field of power equipment fault diagnosis, and the method comprises the steps: obtaining the historical electric quantity data of a secondary side under the normal operation of the voltage transformer, and carrying out the noise reduction and normalization preprocessing; establishing an initial principal component analysis model according to the preprocessed historical electric quantity data, and calculating to obtain a statistic control threshold value; updating a mean vector and a covariance matrix of the model by adopting a dynamic strategy based on real-time acquired new electric quantity data of the secondary side of the voltage transformer; and calculating a new statistic according to the updated mean vector and the covariance matrix, comparing the new statistic with a statistic control threshold value, and if the new statistic is greater than the statistic control threshold value, determining a metering error fault. According to the invention, the model parameters can be updated according to the real-time change data output by the voltage transformer, the adaptability to different metering error ranges of the voltage transformer is improved, and the detection precision is improved.

The present application provides a converter and a chopper transistor blocking control method therefor. According to the chopper transistor blocking control method, when switching transistors in a converter need to be blocked, switching transistors in a primary side circuit connected to a transformer of the converter are blocked, and switching transistors in a secondary side circuit are blocked when the current on a branch where a secondary side winding in the transformer is located is zero, or batch blocking of the switching transistors in the secondary side circuit is completed after the current on the branch where the secondary side winding is located recirculates to zero, thereby avoiding overvoltage damage to the switching transistors caused by the current on the branch where the secondary side winding is located recirculating by means of the junction capacitance of the switching transistors in the secondary side circuit.

The invention relates to a multi-phase magnetic coupling structure, a series compensation circuit and a wireless charging system, and relates to the technical field of wireless power transmission, the multi-phase magnetic coupling structure comprises a primary side magnetic energy emission structure and a secondary side magnetic energy receiving structure, the primary side magnetic energy emission structure comprises a first magnetic core and an emission coil; the secondary side magnetic energy receiving structure comprises a second magnetic core and a receiving coil; the transmitting coil and the receiving coil are both multi-phase bipolar coils; therefore, the magnetic coupling structure provided by the invention is higher in magnetic field intensity, higher in power density and obviously improved in transmission efficiency, the transmission efficiency of the structure can reach more than 94% after the front end voltage is increased to 50V, and the highest efficiency is close to 96%.

The invention discloses a hybrid rectifier bridge LLC resonant converter with a wide output voltage range and a control method thereof, and belongs to the technical field of power generation, power transformation or power distribution. The converter comprises a primary-side inversion network, a resonance network, a high-frequency transformer bank and a secondary-side hybrid rectification network with a bidirectional switch, and ultra-wide output voltage gain is achieved. According to the control method, the primary side adopts phase shift control, and the secondary side adaptively switches the working modes of the full-bridge rectification network and the voltage doubling rectification network through a superposition type asymmetric PWM (Pulse Width Modulation) and phase shift control mode, so that a half-cycle soft switching is provided for the bidirectional switch while the voltage regulation range is greatly widened, and the voltage regulation efficiency is improved. And meanwhile, the loss of the diode is greatly reduced, and the optimization between low switching loss and low conduction loss is realized. According to the invention, free switching between a high-voltage mode and a low-voltage mode can be realized under the condition that the original advantages of LLC are kept, the control method is simple and effective, and improvement of conversion efficiency can be ensured while an ultra-wide output voltage range is realized.

The invention relates to a direct-current circuit breaker based on a thyristor and an on-off method of the direct-current circuit breaker, and belongs to the technical field of direct-current middle-high voltage power system fault protection. The direct-current circuit breaker comprises a main switch branch, a current transfer branch, a voltage-limiting energy consumption branch and a pulse commutation loop, the direct-current circuit breaker is connected with a power system in series, and the main switch branch is connected with the current transfer branch. Two nodes connected in series are respectively marked as Q1 and Q2, the main switch branch and the voltage-limiting energy consumption branch are connected in parallel through the Q1 and Q2, one ends of secondary sides of two high-frequency transformers in the pulse commutation loop are respectively connected to the Q1 and Q2, and the other ends of the secondary sides of the two high-frequency transformers in the pulse commutation loop are respectively connected to two ends of the current transfer branch. The problem that in the prior art, a large number of pulse charging and discharging loops are configured for meeting the fault large-current breaking requirement, and consequently the size and cost are increased is effectively solved.

The invention discloses a variable-frequency reconfigurable wireless electric energy transmission system and a parameter design method, and relates to a wireless electric energy transmission system and a parameter design method. The invention aims to solve the problem that approximately constant power transmission is difficult to maintain in the prior art for relatively wide coupling coefficient fluctuation. The system comprises a full-bridge inverter circuit, a primary side compensation network, a coupling coil, a secondary side compensation network and a rectification filter circuit. The input end of the full-bridge inverter circuit is connected with a direct-current voltage source UD, the output end of the full-bridge inverter circuit is connected with the input end of the primary side compensation network, the output end of the primary side compensation network is connected with the primary side input end of the coupling coil, and the secondary side output end of the coupling coil is connected with the input end of the secondary side compensation network. The output end of the secondary side compensation network is connected with the input end of the rectification filter circuit, and the output end of the rectification filter circuit is connected with the battery load Ro. The invention belongs to the technical field of wireless power transmission.

The invention discloses a CLLLC converter light load efficiency improvement and load expansion circuit based on variable resonant cavity regulation and control and a control method thereof. The circuit comprises a primary side full bridge, a variable resonant cavity, a secondary side rectifier and an output loop, the digital control unit detects the load in real time, and drives and switches the parallel or series capacitor branch to adjust the equivalent resonant capacitor; and the auxiliary buffer branch is used for soft start and sudden change buffer. According to the control method, capacitance is reduced during light load, efficiency is improved, capacitance is increased during heavy load, gain linearity is kept, the load range is widened, and smooth starting is achieved. The device is compact in structure and easy to control, the light load efficiency can be remarkably improved, the load application range is expanded, and the device has high reliability and good industrialization prospects.

The disclosure provides a method for improving the efficiency of a micro-inverter, and a dual-active-bridge-type micro-inverter. The method including: performing power modulation mode switching of a dual-active-bridge-type micro-inverter, such that the power is bi-directionally transmitted from a direct-current side to an alternating-current side and from the alternating-current side to the direct-current side, thereby reducing an effective value of a secondary side current of a transformer; and according to the modulation mode switching characteristic of the dual-active-bridge-type micro-inverter within a power frequency period, performing hybrid optimization on the turn ratio of a primary side to a secondary side and a transformer leakage inductance of a high-frequency transformer of the dual-active-bridge-type micro-inverter.

The invention relates to a direct current bias suppression device and method for a dual-active bridge and a dual-active bridge system, and the device comprises a high-frequency signal detection module which receives the primary side current and the secondary side current of a high-frequency transformer in the dual-active bridge, converts the primary side current and the secondary side current into voltage signals, and outputs the voltage signals to a control module; obtaining a primary side current detection signal and a secondary side current detection signal; the peak value detection module is used for detecting the maximum value and the minimum value of the primary side current in the primary side current detection signal and the maximum value and the minimum value of the secondary side current in the secondary side current detection signal; the sampling module is used for sampling the maximum value and the minimum value of the primary side current and the maximum value and the minimum value of the secondary side current; the control module is used for calculating the difference value between the sum value of the maximum value and the minimum value of the primary side current and zero and the difference value between the sum value of the maximum value and the minimum value of the secondary side current and zero, and obtaining the duty ratio adjustment amount of the primary side and the duty ratio adjustment amount of the secondary side by using the PI controller; and the direct-current bias current on the two sides of the dual-active bridge is suppressed according to the duty ratio adjustment amount.

The invention belongs to the technical field of mutual inductor verification, and particularly relates to a data processing method for testing a current mutual inductor, so as to solve the technical problem that an existing verification method cannot truly reflect the comprehensive error of the mutual inductor, and the method comprises the following steps: S1, obtaining the current waveform data of a tested current mutual inductor; s2, deducting the exponential decay aperiodic component from the original current waveform data to obtain corrected current waveform data; s3, reconstructing to obtain de-noised current waveform data; s4, acquiring fundamental waves of the primary side current and the secondary side current and setting amplitude and phase angles of subharmonics; s5, calculating an initial ratio error and an initial angle error of the current transformer; s6, generating a ratio error compensation vector and an angular difference compensation vector; and S7, respectively carrying out vector summation on the initial ratio error and the initial angle error with the ratio error compensation vector and the angle error compensation vector to obtain the final ratio error and the final angle error of the current transformer. And the test accuracy and reliability of the ratio difference and the angle difference of the current transformer are improved.

The invention discloses a general transient DC bias suppression method for a dual-active-bridge converter under bidirectional power flow. The method comprises the following steps: when the dual-active-bridge DC converter operates stably, asynchronous carriers are generated; a certain modulation and control strategy is adopted, closed-loop operation is carried out in each switching period, and a primary side inner shift phase ratio D1, a secondary side inner shift phase ratio D2 and an outer shift phase ratio Df are generated; different working modes are selected according to the positive and negative relation of the external shift comparison between the current switching period and the previous switching period, and an asynchronously updated modulation wave is generated; and according to the selected working mode, determining a lead and lag relationship of the modulation wave, comparing the modulation wave with the carrier wave, and generating a driving signal of a power switch of the dual-active bridge converter. According to the method, the problem that an existing transient direct current bias suppression method is only suitable for a specific power flow direction or a specific modulation strategy can be solved, transient direct current bias suppression under power bidirectional flow is achieved, and safe operation of the dual active bridge converter is guaranteed.