6results about How to "Reduce current stress" patented technology

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.

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.

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 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.