16results about How to "Reduce current stress" patented technology

The application discloses a Sepic type power correction circuit based on a switched inductor, which comprises switching tubes S1-S3, diodes D1-D5, inductors L1-L5, capacitors C1 and C o The diodes D3-D5 and the inductors L4 and L5 form a switched inductor structure, and the voltage gain of the converter is D / (2-D). Compared with a conventional Sepic PFC converter, the Sepic type power correction circuit based on the switched inductor improves the step-down gain, ensures that the whole duty cycle range is in a step-down state, and has a larger duty cycle than the conventional Sepic PFC converter in the case of a high step-down ratio, thereby effectively avoiding the emergence of a limit duty cycle. The no-bridge structure can realize lower conduction loss. The original output diode is replaced by the switched inductor structure, so that the output current is continuous, and the output current can be filtered. All the switching tubes are common ground, and a lower-cost driving circuit can be used.

The application discloses a kind of based on single-stage grid-connected micro-reverse soft switching online real-time monitoring and closed-loop maintenance control method and system, mainly solve the problem of existing zero-voltage opening / non-zero voltage opening boundary difficult to judge and light load zero-crossing region loss soft switch leads to hard opening, its scheme includes: sampling the real-time state variable operated in single-stage grid-connected micro-reverse circuit, based on the sampled photovoltaic side voltage, photovoltaic side current, grid side voltage and grid side phase, respectively calculate internal and external moving phasor;Custom dead time and target level, according to the dead time and the sampled bridge arm commutation current, bridge arm commutation voltage and switching node voltage judge the soft switching state when commutation event k time;Based on the soft switching state, calculate the corrected internal and external moving phasor, output the driving signal of switch tube, to realize the soft switching online real-time monitoring and closed-loop maintenance of single-stage grid-connected micro-reverse.The application can improve the robustness of soft switching implementation, reduce the risk of hard opening, and can be used for soft switching control and energy transmission of single-stage grid-connected micro-reverse.

The application discloses a transient midpoint potential collaborative suppression method suitable for a network-constructed three-level T-type inverter and belongs to the technical field of power electronic converter control. In view of the problem that the three-level T-type inverter is prone to midpoint potential deviation in the process of grid frequency disturbance in a wind storage network-constructed scene, the application comprises the following steps: a low-frequency coupling model is established, in which active disturbance is transmitted to midpoint potential through d-axis current and midpoint current; event-triggered logic with hysteresis characteristics is constructed according to frequency deviation; a power shaping link is arranged at a source end, active instructions in an event window are subjected to second-order shaping, amplitude limiting and change rate constraint processing; a zero sequence extended state observer is arranged at a terminal side, online estimation is conducted on the generalized disturbance of a midpoint channel, and an additional compensation quantity is generated through a zero sequence port; and the source end power shaping and the terminal side zero sequence extended state observer are collaboratively put into the same event window, so that low-frequency disturbance entering the midpoint channel is weakened and the cumulative deviation of the midpoint potential is suppressed. The application can effectively reduce the midpoint potential peak value, suppress low-frequency energy accumulation, reduce transient peak current stress, and improve the operation safety and control stability of the network-constructed three-level converter under strong disturbance working conditions.

The application discloses a bridgeless Cuk PFC converter based on a switched-inductor-capacitor structure, which comprises switching tubes S1-S3, diodes D1-D4, inductors L1-L5, capacitors C1, C2 and C o The diodes D3 and D4, the capacitor C2 and the inductors L3 and L4 form a switched-inductor-capacitor structure. The original freewheeling diode is replaced by the switched-inductor-capacitor structure, so that the voltage gain of the converter is D / 2(1-D), compared with a traditional Cuk PFC converter, the converter realizes positive voltage output and improves the voltage reduction gain, and the duty cycle range in the voltage reduction mode is wider. Meanwhile, the bridgeless structure is adopted, so that lower on-state loss can be realized. The converter has continuous input and output currents, high power factor and high efficiency, and has rich application.

This invention relates to a multi-resonant, multi-step-down ratio switched-capacitor converter, belonging to the field of power electronics technology. The invention addresses the technical problem of existing switched-capacitor converters struggling to achieve multiple fixed step-down ratios while maintaining high efficiency and high power density within the same topology. The invention includes: an input port; a switching network composed of fourteen MOSFET switches; a capacitor network composed of five flying capacitors; and first and second resonant inductors connected between the switching network and the output side. The converter is a single-stage topology, with the above components forming a single resonant network. By adjusting the switching timing, three fixed step-down ratios—8:1, 4:1, and 2:1—can be achieved within the same topology. The converter operates in open-loop mode, with the switching frequency matching the resonant frequency, achieving zero-current switching for all switches. The two-phase circuits on the output side operate in a staggered 180° manner to reduce current stress. The output side also includes first and second output ports connected in parallel, along with an output filter capacitor, which, after filtering, jointly supply power to the load.

The embodiment of the invention provides a frequency conversion and phase shift control method for an SSDAB converter for expanding the applicable power range of MBD-GaN, and relates to the technical field of converter control, and the method comprises the steps: obtaining an AC side voltage, an AC side current and a DC side voltage of a single-stage dual-active bridge SSDAB converter through setting an initial switching frequency; obtaining a voltage gain parameter and a normalized power parameter; obtaining a real-time operation interval according to a preset operation interval judgment mechanism; and taking minimization of a switch stress factor as a target to obtain a limited switch frequency, an inner phase shift quantity, an outer phase shift quantity and an outer phase shift angle, and inputting the values into a PWM module to generate a driving signal so as to complete frequency conversion and phase shift control of the SSDAB converter. The problem that the applicable power range of an MBD-GaN device is limited when an SSDAB converter is in a high-power working condition in the prior art is solved. And the effects of greatly reducing the current stress and the current effective value, reducing the switching loss and expanding the power application range are achieved.

The invention relates to the field of power electronic conversion, and particularly discloses a two-degree-of-freedom soft switching modulation method for a 4L-NPC dual-active bridge converter, which comprises the following steps: acquiring system parameters, determining a first control quantity D1 and a second control quantity D2, and dividing operation modes; generating a switch driving time sequence enabling the primary side to output four-level waveforms according to the D1 and the D2; establishing an inductive current model based on the time sequence, and calculating a transmission power and a key switch moment current value; and based on a calculation result, determining an optimal combination of D1 and D2 by combining a zero-voltage opening constraint and a current effective value minimization target, and generating a final driving signal. Through two-degree-of-freedom cooperative modulation, the soft switching range is effectively widened in a wide voltage gain range, meanwhile, the current peak value and the effective value are remarkably reduced, and the balance between efficiency improvement and control complexity is achieved.

This invention discloses a temperature-adaptive heating method and system for lithium-ion batteries at low temperatures. The method selects between off-grid and grid-connected heating modes based on the lithium-ion battery state: In off-grid mode, the power devices inside the energy storage converter, along with the AC-side filter inductor, filter capacitor, and battery cluster units, are reconstructed into a closed internal resonant heating circuit. AC heating current is generated by periodically switching the power devices on and off to excite resonance. In grid-connected mode, the energy storage converter is controlled to periodically switch between rectification and inversion states to generate AC heating current. The method also involves three-phase bridge arm drive control and dynamic switching, battery cluster group heating, lithium plating prevention protection based on calibration tables and lithium plating indicators, bias current regulation, and DC support capacitor switching. This invention reuses existing hardware of the energy storage converter to achieve dual-mode adaptive heating without requiring additional power equipment, balancing heating efficiency and battery safety.

The invention relates to the technical field of electronics, in particular to a boost inverter circuit and a driving method. Specifically, the boost inverter circuit comprises a boost module and an inverter module, the boost module comprises a first push-pull unit and a second push-pull unit, the input end of the first push-pull unit and the input end of the second push-pull unit are connected in parallel to form a boost input end, and the boost input end is used for being connected with a direct-current power supply. The output end of the first push-pull unit and the output end of the second push-pull unit are connected in parallel to form a boost output end, and the boost module is used for performing boost processing on first direct current of the direct-current power supply through the first push-pull unit and the second push-pull unit to output second direct current; the inversion module is connected with the boost output end of the DC boost module, and the inversion module is used for carrying out inversion processing on the second DC so as to output the target AC. Current flowing through a single push-pull unit is dispersed through the first push-pull unit and the second push-pull unit which are connected in parallel, so that the current stress of a switching tube is reduced.

This invention discloses a three-phase unified power quality regulator (UPQC) control method, comprising the following steps: acquiring system modulation parameters and setting active vectors; synthesizing virtual vectors based on the active vectors; distributing the virtual vectors and active vectors in different sectors; calculating the action time of the virtual vectors and the action time of the active vectors in different sectors; and outputting a PWM signal to control the operation of the power quality regulator based on the action time of the virtual vectors and the action time of the active vectors. This invention effectively suppresses the DC bus inductor current ripple of the unified power quality regulator by controlling the virtual vector action sequence and virtual vector action time, thereby reducing not only the hysteresis loss and eddy current loss on the inductor, but also the current stress and switching loss of the series and parallel converters, improving system efficiency and system operating performance.

This invention discloses a DC bias suppression method for renewable energy access-type TAB converters based on operating condition mode classification, belonging to the fields of DC converters and power electronics. This method suppresses transient DC bias generated when the operating condition of a single output port of an isolated three-port converter changes. In implementation, the suppression time of transient DC bias is greatly accelerated by operating all three ports simultaneously. Due to the coupling relationship between the first port and the other two ports, a port compensation scheme is designed when the first port is in operation. By modeling the transient DC bias under the full-cycle, full-phase-shift state, real-time suppression of transient DC bias in isolated three-port converters can be achieved under conditions such as arbitrary operating condition switching and operating condition changes at any time during the working cycle.

The application discloses a power module and a modular power supply, comprising a multi-winding high-frequency transformer, a power frequency rectifier, a high-frequency converter, a diode rectifier bridge, an LC branch, a direct-current interface circuit and an equalization interface circuit; according to the port composition type, the application is divided into the following three parts: the first part is connected with the primary side high-frequency converter through the LC branch, the primary side high-frequency converter is connected with the power frequency rectifier, and the power frequency rectifier output constitutes an alternating current port; the second part is connected with the secondary side rectifier bridge through the LC branch, the secondary side rectifier bridge is connected with the direct-current interface circuit, and the direct-current interface circuit output constitutes a total direct-current port; the third part is connected with the equalization interface circuit through the LC branch, and an equalization port is constituted. The application greatly reduces the volume and weight of the magnetic element, improves the power density of the equipment, introduces the resonance technology to reduce the switching loss and improve the system efficiency, and is matched with independent AC accessories to construct a three-phase four-wire alternating current port, and provides multiple types and multiple functions of electrical interfaces.

The present application relates to the field of direct current transformer, in particular to a kind of modular multilevel direct current transformer modulation and control method, by controlling the phase shift angle size between different half-bridge module drive signals of half-bridge module valve group, modulation generates the asymmetric ladder wave with two rising slopes and falling slopes, and by detecting the output voltage size, the rising slope and the falling slope of the asymmetric ladder wave of modular multilevel direct current transformer half-bridge module valve group output are changed and the duty cycle of full-bridge module switch tube, so as to adjust the output voltage of modular multilevel direct current transformer.The modulation and control method realizes the fixed-frequency operation of resonant circuit, reduces the design difficulty of magnetic element, while realizing the zero-current turn-off of full-bridge module switch tube on the low-voltage side of modular multilevel direct current transformer, can reduce current stress and improve the working efficiency of converter.

The invention discloses an interleaved parallel voltage-stabilizing wireless charging system, which belongs to the field of wireless charging and comprises a primary side and a secondary side. The primary side comprises a direct-current power supply VIN, an inverter circuit and a primary side compensation and transmitting coil and is used for transmitting energy to the secondary side; and the secondary side comprises a receiving coil, a secondary side compensation circuit, a rectification circuit and two voltage stabilizing circuits which are connected in parallel in an interleaving manner, and is used for receiving the energy of the primary side and adjusting the output power. The system does not depend on primary side power adjustment, control over the output power is achieved only through the secondary side voltage stabilizing circuit, a communication system between the primary side and the secondary side is not needed, communication delay does not exist, and the structure is simple. According to the system, through the current sharing design, the two voltage stabilizing circuits connected in parallel are used for shunting output current, and the current stress of a switching tube is reduced. In addition, through phase control between the two voltage stabilizing circuits, output voltage and output current ripples can be reduced, and then the requirement for output capacitance is reduced.

The invention discloses a direct-current high-voltage bidirectional power supply module which comprises a high-frequency transformer and a control circuit, a primary side of the high-frequency transformer is connected with a primary bridge arm, a secondary side of the high-frequency transformer is connected with a secondary bridge arm, the ratio of the number of turns of the primary side of the high-frequency transformer to the number of turns of the secondary side of the high-frequency transformer is 1: 1, and the primary bridge arm and the secondary bridge arm are respectively connected with the control circuit. According to the control circuit, the phase shift duty ratio between an original bridge arm and an auxiliary bridge arm is controlled in a double-closed-loop mode through a voltage and current control loop, so that two-way transmission of power is achieved; the input and output are both 540V, the rated power is 15KW, adjustment of output voltage, voltage stabilization and current stabilization can be realized, the size of output limited current and various protection requirements can be adjusted in real time, the output voltage control and the output voltage protection adopt a transformer and inductor physical isolation mode to collect voltage signals, the switching loss can be reduced, and the switching efficiency is improved. And the transmission efficiency and the operation stability of the bidirectional power supply module under high switching frequency are improved.