Abstract: The present invention discloses a hybrid-equivalence-based power electronics system partition computing method, and relates to the field of power electronics simulation. In the power electronics system partition computing method, by separating series nodes and parallel nodes from internal nodes, converting the series nodes into an impedance form, and converting the parallel nodes into an admittance form, hybrid equivalent conversion of sub-partitions is implemented. By projecting hybrid equivalent matrices and hybrid excitation matrices of the sub-partitions onto a global coupling coordinate system, there is linear additivity between the hybrid equivalent matrices of the sub-partitions, and a series coupling current and a parallel coupling voltage of a system are efficiently solved, thereby implementing parallel partition decoupling computing of the power electronics system.

Abstract: The present invention discloses a gas cylinder weighing type hob, wherein one side of a support carrier is hinged for rotation, and the other side acts on a weight sensor to perform single-side weight detection, the use of only one single weight sensor results in a simpler structure, and a large amount of detection data from the weight sensor may be subject to data fitting to obtain a corresponding equation as a conversion equation of a residual amount of gas in a gas cylinder to detect the residual amount of gas.

Abstract: The present invention provides a fermentation process for improving the production level of a recombinant human collagen. The process comprises inoculating a sterilized fermentation medium with a Pichia yeast solution, then performing fermentation culturing for 14-18 hrs, adding methanol to induce the expression, upon which sodium pyruvate is added to the fermentation medium, wherein the amount of the sodium pyruvate added is 0.01-10 g/L. In the fermentation process of the present invention, the sodium pyruvate is added in the methanol-induced expression stage, so that the biosynthesis rate of the recombinant human collagen is improved; and a continuous feed-batch mode is adopted, so that the biosynthesis rate of the recombinant human collagen is further improved, and the fermentation time is shortened. Meanwhile, the expression level of the recombinant human collagen is increased, the fermentation level is increased by more than 20%, and the production cost is reduced.

Abstract: The present invention discloses a fermentation process with a Pichia yeast expressing a recombinant protein, in which Pichia pastoris is used as a fungal strain. The process comprises performing primary seed culturing to reach a fungal concentration of 20±2 g/L; then performing secondary seed culturing to reach a fungal concentration of 120±10 g/L; next proceeding to a glycerol culturing stage, wherein the amount of glycerol added in the glycerol culturing stage is 60-70 g/L; and then proceeding to a methanol-induced stage for 120±8 h after the dissolved oxygen quickly reaches a relatively stable state, to complete the fermentation process. In the present invention, a glycerol fed-batch addition stage in existing processes is omitted, and the process proceeds to a next stage as soon as glycerol is completely consumed, with no need to prepare sterilized glycerol for fluidic addition. As such, the glycerin sterilizer is omitted, the consumption of energy and resource and the waste of glycerin are reduced.

Abstract: The present invention discloses a fermentation process with a Pichia yeast expressing a recombinant protein, in which Pichia pastoris is used as a fungal strain. The process comprises performing primary seed culturing to reach a fungal concentration of 20±2 g/L; then performing secondary seed culturing to reach a fungal concentration of 120±10 g/L; next proceeding to a glycerol culturing stage, wherein the amount of glycerol added in the glycerol culturing stage is 60-70 g/L; and then proceeding to a methanol-induced stage for 120±8 h after the dissolved oxygen quickly reaches a relatively stable state, to complete the fermentation process. In the present invention, a glycerol fed-batch addition stage in existing processes is omitted, and the process proceeds to a next stage as soon as glycerol is completely consumed, with no need to prepare sterilized glycerol for fluidic addition. As such, the glycerin sterilizer is omitted, the consumption of energy and resource and the waste of glycerin are reduced.

Abstract: The present invention provides a fermentation process for improving the production level of a recombinant human collagen. The process comprises inoculating a sterilized fermentation medium with a Pichia yeast solution, then performing fermentation culturing for 14-18 hrs, adding methanol to induce the expression, upon which sodium pyruvate is added to the fermentation medium, wherein the amount of the sodium pyruvate added is 0.01-10 g/L. In the fermentation process of the present invention, the sodium pyruvate is added in the methanol-induced expression stage, so that the biosynthesis rate of the recombinant human collagen is improved; and a continuous feed-batch mode is adopted, so that the biosynthesis rate of the recombinant human collagen is further improved, and the fermentation time is shortened. Meanwhile, the expression level of the recombinant human collagen is increased, the fermentation level is increased by more than 20%, and the production cost is reduced.

Abstract: Disclosed in the present invention is a four-port power electronic transformer based on a hybrid modular multilevel converter (MMCs). The four-port power electronic transformer includes a hybrid MMC, direct current (DC)/DC converters, and an inverter. Each DC/DC converter includes a front stage part, a high frequency transformation part and a back stage part.

Abstract: Disclosed in the present invention is a four-port power electronic transformer based on a hybrid modular multilevel converter (MMCs). The four-port power electronic transformer includes a hybrid MMC, direct current (DC)/DC converters, and an inverter. Each DC/DC converter includes a front stage part, a high frequency transformation part and a back stage part.

Abstract: A method of data transmission between power electronic devices without a communication line involves generation of a digital signal in a data transmission process. The digital signal enables PWM modulation of specific data information via a composite modulation method. The composite modulation superimposes PWM modulation waves after modulating the PWM carrier frequency or conducting high-frequency modulation on the data. The composite modulation generates a PWM drive pulse signal which is transmitted to a power circuit via a main power electronic circuit to complete the data transmission process. In the data receiving process, signals are extracted on the voltage and current of a power line via software or hardware, and data demodulated to obtain the data information to complete the data receiving process.

Abstract: A method of data transmission between power electronic devices without a communication line involves generation of a digital signal in a data transmission process. The digital signal enables PWM modulation of specific data information via a composite modulation method. The composite modulation superimposes PWM modulation waves after modulating the PWM carrier frequency or conducting high-frequency modulation on the data. The composite modulation generates a PWM drive pulse signal which is transmitted to a power circuit via a main power electronic circuit to complete the data transmission process. In the data receiving process, signals are extracted on the voltage and current of a power line via software or hardware, and data demodulated to obtain the data information to complete the data receiving process.