12results about How to "Reduce switching frequency" patented technology

The invention belongs to the technical field of motor control, and discloses a motor model prediction control method based on asymmetric hybrid vector pulse width modulation. Six sectors of a space voltage vector are divided into odd number sectors and even number sectors. In a singular sector, only a zero vector and a corresponding non-zero effective vector are adopted to perform two-section asymmetric synthesis, so that only one switching state change occurs in one period; in an even number sector, a non-zero effective vector in the sector, a non-zero effective vector in an adjacent odd number sector screened by a cost function and a zero vector are adopted to carry out three-section type asymmetric synthesis, and unnecessary switching actions are avoided while the current tracking performance is ensured. By means of the method, targeted control over the switching times is achieved in different sectors, and the average switching frequency is reduced. In the even-number sectors, optimization is carried out between the non-zero effective vectors of the adjacent odd-number sectors, the current prediction error is further optimized under the condition that the switching frequency is not obviously increased, and the current performance is ensured.

The application relates to a frequency multiplication circuit and a frequency multiplication device. The frequency multiplication circuit comprises a first high-voltage switch circuit, a second high-voltage switch circuit and a delay circuit. The application replaces the operational amplifier in the traditional frequency multiplication circuit with the first high-voltage switch circuit, the second high-voltage switch circuit and the delay circuit, can generate a frequency multiplication signal based on a reference pulse signal and an input voltage, and can adapt to a high-voltage environment. Meanwhile, since the frequency multiplication signal is obtained by synthesizing the pulse signals output by the first high-voltage switch circuit and each second high-voltage switch circuit, a single first high-voltage switch circuit or second high-voltage switch circuit only needs to output a pulse in the period of a reference pulse signal, thereby avoiding the problem that a single high-voltage switch circuit cannot directly output a high-frequency signal due to a low switching rate of the single high-voltage switch circuit.

This application provides a general-purpose liquid packaging film, comprising a three-layer co-extruded layer formed by three-layer co-extrusion blown film. The three-layer co-extruded layer includes an inner layer, a middle layer, and an outer layer. The inner layer comprises LLDPE-FG5224, MVLDPE-SP0540, LDPE-2426K, LLDPE-FG5190, and PPA-A1058. The middle layer comprises MLLDPE-1327CA, LLDPE-2056AC, LDPE-2426K, and PPA-A1058. The outer layer comprises LDPE-2426N, LLDPE-7042, MLLDPE-1327CA, and PPA-A1058. This application also provides a method for preparing the general-purpose liquid packaging film. The film produced by the formulation and process provided in this application exhibits physical properties such as tensile strength, elongation at break, and coefficient of friction that are adaptable to the requirements of packaging liquids with different contents, thereby reducing the frequency of formulation changes during production and consequently reducing production costs.

This utility model relates to a dual power supply switching circuit and a dual power supply circuit, belonging to the field of high-voltage switch control technology. The switching circuit includes: a coil of a first contactor and a normally closed contact of a second contactor connected in series to the main power supply line between the main power supply and the electrical load; a normally open contact of the first contactor connected in series on the main power supply line; a coil of the second contactor and a normally open contact of a time relay connected in series to the backup power supply line between the backup power supply and the electrical load; a normally open contact of the second contactor connected in series on the backup power supply line; a coil of an undervoltage relay connected to the main power supply line; and a normally closed contact of the undervoltage relay and a coil of the time relay connected in series to the backup power supply line. This utility model, by using an undervoltage relay and a time relay, reduces frequent switching between main and backup power supplies, and has a simple circuit structure, low cost, and is easy to maintain.

The application discloses a PFC-LLC resonant switching power supply, which comprises a PFC circuit and an LLC circuit, an input end of the PFC circuit is connected with an AC input interface, an output end of the PFC circuit is connected with an input end of the LLC circuit through a high-voltage bus, an output end of the LLC circuit is connected with a DC output interface, and the PFC-LLC resonant switching power supply further comprises a bus voltage sampling circuit, a fault detection circuit, a first enabling control circuit and a second enabling control circuit, an input end of the first enabling control circuit is connected with an output end of the fault detection circuit, an output end of the first enabling control circuit is connected with a voltage sampling end of a PFC control unit of the PFC circuit, a first input end of the second enabling control circuit is connected with the output end of the fault detection circuit, an output end of the second enabling control circuit is connected with a voltage feedback input end of an LLC control unit of the LLC circuit, an input end of the bus voltage sampling circuit is connected with the input end of the LLC circuit, and an output end of the bus voltage sampling circuit is connected with the voltage feedback input end of the LLC control unit.

The application discloses a synchronous link data transmission method, a communication device and a storage medium. The method is used for synchronous link data transmission between a first device and a second device. The synchronous link has a reserved transmission window set at a preset interval. The first device generates a first service data block corresponding to the reserved transmission window in time sequence. The method is executed by the first device. The method comprises the following steps: in response to the fact that data transmission associated with a previous first service data block has been completed in a current transmission window, determining whether the current transmission window has sufficient remaining time; and in response to the fact that the current transmission window has sufficient remaining time, performing data transmission associated with a first service data block to be currently transmitted with the second device. The application can optimize the synchronous link of the pre-allocated time slice, improve the fragmentation problem of the time slice available for other links, reduce the link switching frequency, and improve the scheduling efficiency.

The present application relates to a kind of renewable hydrogen sulfide removing agent and its preparation method and application, the renewable hydrogen sulfide removing agent with silica alumina gel as carrier, by loading aluminium hydroxide colloidal solution to silica alumina gel carrier, continue water vapor aging makes aluminium gel and carrier secondary combination, thereby obtains the hydrogen sulfide removing agent with more concentrated pore size distribution, active adsorption site is more abundant.The removing agent is suitable for the removal of hydrogen sulfide in hydrocarbon organic medium, the use condition range is that hydrogen sulfide concentration is less than 1000ppm, removal precision is less than 0.1ppm.When saturated with hydrogen sulfide, the scavenger can be regenerated under the purge of oxygen-free atmosphere, restore removal capacity, regeneration temperature is 250~300 ℃.Compared with prior art, the hydrogen sulfide removing agent prepared in the present application has more prominent hydrogen sulfide removal capacity, adsorption capacity is increased by 3-5 times, and regeneration cycle is prolonged by 2-5 times.

This invention discloses a series-parallel type switched linear composite envelope tracking power supply, comprising a multilevel converter (VSC), a linear amplifier (VLA), and a switching converter (CSC). The multilevel converter (VSC) and the linear amplifier (VLA) are connected in series, and the switching converter (CSC) and the linear amplifier (VLA) are connected in parallel. The multilevel converter (VSC) tracks the envelope signal and outputs a stepped-wave voltage to fit the load voltage v. o Simultaneously, the stepped waveform voltage output by VSC serves as the input voltage of CSC; the linear amplifier VLA realizes the load voltage v o For the reference signal v ref The switching converter (CSC) outputs current to match the load current. This invention significantly reduces the switching frequency of the CSC and the voltage stress on the switching transistor without increasing the complexity of the series-parallel ET power supply, thereby improving the overall efficiency of the ET power supply.

The utility model relates to a charging protection circuit and a charger. The charging protection circuit comprises a charging switch control module and a square wave generation module, a first end of the charging switch control module is connected with an input power supply, a second end of the charging switch control module is connected with an input end of the square wave generation module, and an output end of the square wave generation module is connected with a third end of the charging switch control module. The fourth end of the charging switch control module is connected with the battery; the square wave generation module comprises a thermistor; when the charging switch control module controls the charging path to be conducted, the resistance value of the thermistor is increased along with temperature rise so as to adjust the period of a square wave signal input to the third end of the charging switch control module by the square wave generation module, and the charging switch control module is used for adjusting the switching frequency of the charging path according to the period of the square wave signal. The charging protection circuit can reduce the temperature of the battery.

This invention discloses an online water quality monitoring system and control method, belonging to the field of water quality monitoring technology. It includes a processing module, a combined valve, a metering device, a peristaltic pump, and a digester. The metering device has a comprehensive metering chamber, a first auxiliary metering chamber, and a second auxiliary metering chamber, respectively corresponding to the isolated metering of non-strongly corrosive reagents, strong acid reagents, and strong alkali or strong oxidizing reagents. Each chamber is equipped with a photoelectric liquid level sensor to achieve precise volume determination. The processing module controls the injection of wastewater in at least three closed-loop batches. The first batches act as a carrier liquid to push reagents and dilute residues, while the last closed-loop batch replenishes the total volume and cleans the pipelines and chambers of residues, using wastewater to replace the cleaning fluid for self-cleaning. This invention can achieve multi-chamber isolated metering, reagent premixing, parallel detection with dual digesters, or time-sharing detection with a single digester, effectively avoiding cross-reactions between acids / alkalis and redox reagents, reducing cleaning fluid consumption and wastewater production, and improving the stability, detection efficiency, and equipment reliability of multi-parameter online monitoring.

The application discloses a kind of composite multi-path multi-cut full-automatic ultra-low temperature cold trap water removal system, including standard gas and quality control gas input unit, multi-point sampling unit, first-stage gas delivery unit, second-stage gas delivery unit, double-temperature-zone refrigeration / heating unit, main control unit;Multi-point sampling unit, first-stage gas delivery unit, double-temperature-zone refrigeration / heating unit in first-stage temperature zone, second-stage gas delivery unit, double-temperature-zone refrigeration / heating unit in second-stage temperature zone are sequentially communicated, the application is applicable to cold trap technical field, system integration degree is high, without additional additional components or equipment such as rotary valve can complete the gas source switching of different purposes, simultaneously using two-stage gas delivery design, ensure that the function of each unit is independent and the flow rate of each gas channel reaches the set target, and using double-temperature-zone design, reduce the switching frequency between cold trap module, prolong the service life of equipment, under the premise of guaranteeing that target gas composition is not disturbed, maximum efficiency removes water vapor contained in the gas to be measured.

An assembled wireless charging road magnetic guide surface layer unit and a construction method thereof, which relate to the technical fields of wireless charging roads and assembled pavement structures. The unit is used for solving the problems of magnetic shielding, difficult implementation of discrete partition construction on site, and low integration of wireless charging modules and road surface layer structures in the prior art. The magnetic guide surface layer unit comprises an electromagnetic module and a prefabricated asphalt concrete surface layer plate. The electromagnetic module comprises a GFRP bottom support, an electromagnetic shielding plate, a transmitting coil, a local pouring seal layer and a GFRP top plate. The prefabricated asphalt concrete surface layer plate comprises a magnetic guide asphalt mixture area and a common asphalt mixture area. The construction method comprises the steps of prefabrication of an assembled composite functional unit, layout of a roadside power supply system, setting of a power supply line channel, civil preparation of a road functional area, installation of the functional unit, electrical connection, joint treatment and system debugging and detection. The unit is used for wireless charging roads for electric vehicles.