7results about How to "Improve light load efficiency" patented technology

This invention relates to a method for improving the light-load efficiency of a synchronous rectifier chip. The method involves monitoring the voltage V between the output terminal K and the input terminal A of the synchronous rectifier chip. KA The V KA This reflects the change in load current; when the V KA When the voltage drops to the first preset voltage, based on V KA = -Is×Rdson is used to dynamically pre-adjust the Vgs drive voltage to counteract the Vgs voltage drop caused by the decrease in load current Is. KA The change extends the turn-on time of the synchronous rectifier chip; Rdson is the on-resistance of the MOSFET inside the synchronous rectifier chip; the dynamic pre-adjustment processing of the Vgs drive voltage includes: controlling the reduction of the Vgs drive voltage, utilizing the characteristic that Rdson increases as Vgs decreases in the MOSFET, and maintaining Vgs. KA The voltage remains constant.

The application discloses a control method and system of a charging module and a charging system. The method comprises the following steps: collecting the operating parameters of the charging module; calculating the comprehensive discriminant value of the coupling multi-factor composite working condition according to the input voltage, output current, module temperature and battery state of charge; adjusting the power distribution ratio of the battery and the energy storage unit according to the comprehensive discriminant value; judging whether the charging module needs to switch the working condition according to the input voltage and output current and outputting the corresponding control signal to control the charging module; solving the first switching frequency with the maximum efficiency of the charging module as the target, adjusting the first switching frequency according to the current working condition to obtain the optimal switching frequency; performing adaptive PI adjustment on the current loop according to the output current to output the optimal switching duty ratio; and controlling the charging module according to the optimal switching frequency and the optimal switching duty ratio. The application enables the charging module to maintain high efficiency and stable operation within a wide input, wide output and wide load range.

The invention relates to the technical field of switching power supplies, and discloses a two-stage active power factor correction circuit and a switching power supply in order to solve the problems of low power factor and high harmonic pollution caused by the fact that the input of the switching power supply is alternating current. The circuit comprises an electromagnetic interference filter, a rectifier bridge, a PFC booster circuit, an LLC half-bridge resonance compensation circuit and a controller which are connected in sequence. The PFC booster circuit is used for boosting the voltage output by the rectifier bridge to the high-voltage direct-current bus voltage; the LLC half-bridge resonance compensation circuit is used for converting the high-voltage direct-current bus voltage output by the PFC booster circuit into stable low-voltage direct current required by a load by adjusting the switching frequency of the LLC half-bridge resonance compensation circuit; the controller is used for controlling the working mode of the PFC booster circuit according to the magnitude of the output current of the LLC half-bridge resonance compensation circuit; meanwhile, the output voltage of the LLC half-bridge resonance compensation circuit is sampled, and the switching frequency of the LLC half-bridge resonance compensation circuit is adjusted according to feedback of the output voltage. By adopting the circuit, the power utilization efficiency of power equipment is improved, and harmonic interference is reduced.

This invention discloses a wide-range radio frequency power conversion system based on an asymmetric hybrid structure and hybrid modulation. It adopts an input parallel, output series architecture, consisting of a main power regulation module and several auxiliary power modules. The main power regulation module includes a front-stage Buck-Boost converter and a rear-stage dual-parallel full-bridge resonant unit, possessing fine voltage and phase adjustment capabilities. The auxiliary power modules are simplified full-bridge units, responsible only for discrete power switching. The system employs a hybrid modulation strategy, utilizing phase-shift control of the main power module in the low-power range, DC bus voltage regulation of the main power module in the medium-power range, and full-bridge / bypass mode switching of the auxiliary power modules in the high-power range, achieving smooth and continuous adjustment from zero to rated power. This architecture, through optimized design of resonant network parameters and utilization of the internal resonant circulating current generated by the main module in phase-shift state, ensures zero-voltage switching (ZVS) operation across the entire range, significantly reducing system hardware costs and control complexity while significantly improving system efficiency in power back-off state.

The present application relates to a kind of current mode-based fixed-frequency PWM controller and control method, belong to analog integrated circuit design field.The fixed-frequency PWM controller includes: filter and feedback module, error amplification and compensation module, voltage current conversion module, first difference module, second difference module, clock generator, PWM trigger and drive module and switching power stage.The present application utilizes the current information of the output VCOMP voltage of error amplification and compensation module, using voltage current conversion module and difference module, so that light load when fixed-frequency PWM controller automatically enters light load variable frequency, its circuit structure and control logic are simple, and light load efficiency is high, PFM entry point can be predicted, and additional operational amplifier is not needed to do PFM management, circuit simplicity is high, with strong portability and lower difficulty of implementation.

The utility model discloses a kind of high voltage input LLC control circuit, including control unit, isolation unit, upper switch device, lower switch device, sampling unit and resonance unit, sampling unit includes capacitor C8 and capacitor C9, the first end of capacitor C8 is as the first input end of the sampling unit, the second end of capacitor C8 is connected with the first end of capacitor C9 and is as the output end of the sampling unit, the second end of capacitor C9 is as the second input end of the sampling unit, sampling unit is used to output to the control unit after voltage voltage reduction voltage reduction, so that the control unit controls the upper switch device conduction when rising edge disappears, and control lower switch device conduction when falling edge disappears.The utility model can reduce the power loss of sampling unit, improve the efficiency of circuit, reduce the occupied space of sampling unit, while can improve voltage sampling effect, avoid the system control defect caused by uneven voltage division.

This invention discloses a composite soft magnetic powder core and its preparation method. FeSiAl magnetic powder is added to a mixture of phosphoric acid and ethanol, stirred, and then dried to obtain insulating FeSiAl powder. Tetraethyl orthosilicate and anhydrous ethanol are added to FeNi magnetic powder, stirred, and then diluted with ammonia solution dropwise while stirring. After drying, insulating FeNi powder is obtained. The insulating FeSiAl and FeNi powders are mixed in a certain proportion to obtain composite metal magnetic powder. The composite metal magnetic powder is sieved and granulated, then a resin binder and zinc stearate are added, pressed into a green body, and annealed at high temperature to obtain the finished FeSiAl / FeNi composite powder core. Through the above methods, this invention provides targeted insulating coating for FeSiAl and FeNi magnetic powders, adjusts the permeability of the two magnetic powders, and achieves adjustment of the DC bias curve of the FeSiAl / FeNi composite powder core. This improves its anti-saturation capability under light load conditions, thereby improving light load efficiency and solving the problem of easy saturation of components in high-power applications.