10results about How to "Increase duty cycle" patented technology

The invention discloses a maximum power point tracking method of a photovoltaic module, control equipment and a photovoltaic system, and relates to the technical field of photovoltaics. The method comprises the following steps: when working in a traversal tracking mode, increasing the duty ratio of a PWM signal of a voltage regulation circuit according to a first duty ratio step length, and obtaining the output power of a photovoltaic module until the output voltage of the photovoltaic module reaches a first voltage; increasing the duty ratio of the PWM signal of the voltage regulation circuit according to a second duty ratio step length, and obtaining the output power of the photovoltaic module until the output voltage of the photovoltaic module meets any condition in the condition set; and determining the working point corresponding to the maximum output power of the photovoltaic module obtained in the traversal tracking mode as the maximum power point of the photovoltaic module. A larger first duty ratio step length is adopted for tracking in an area where the maximum power point is not likely to appear, and a smaller second duty ratio step length is adopted for tracking in an area where the maximum power point is likely to appear, so that the tracking precision and the tracking efficiency are balanced.

The application discloses a thermoelectric pile structure for calibrating a far ultraviolet ultraviolet detector based on MEMS, which comprises a silicon substrate, a support layer, an absorption layer, a thermocouple pair, aluminum wires, aluminum electrodes and a single crystal silicon material structure on the silicon substrate. The double-layer thermocouple stacking structure is adopted to improve the device duty ratio, more thermocouple pairs can be laid in the case of keeping the size of the one-layer structure unchanged, and the response rate of the detector is improved. The circular structure conforms to the distribution trend that the temperature is radially diffused from the center of the absorption layer to the periphery in a decreasing manner, the hot end of the thermocouple pair can be closer to the area with higher temperature, the temperature of the hot end of the thermocouple pair is more uniform, and the response rate of the detector is improved. The radiant energy of the far ultraviolet ultraviolet radiation source is converted into an output thermoelectric electromotive force, a mathematical model of Fourier's law and the Seebeck effect is established for calculation, and the heat flux density of the far ultraviolet ultraviolet radiation source is measured.

The invention relates to a method for determining a rotor position (RP2) of a three-phase permanent magnet synchronous machine (1). Each phase (u, v, w) of the permanent magnet synchronous machine (1) here corresponds to an inductance which changes as a function of the rotor position (RP2). In the method, a voltage (u(t)) is applied across the phases (u, v, w), wherein the applied voltage (u(t)) respectively causes a ripple current (i(t)) for each phase (u, v, w). The ripple current (i(t)) is determined for at least two of the three phases, and the inductance of the respective phase is determined on the basis of the determined ripple current (i(t)) for the respective phase. The rotor position (RP2) is then determined from the changing inductance. The method is also used here in a method for field-oriented regulation of the permanent magnet synchronous machine (1). Furthermore, the invention relates to a control unit (2) for carrying out such a method, and to a steering system having a steering regulator which comprises a permanent magnet synchronous machine (1) having such a control unit (2).

This invention discloses a general fast modulation method for a VIENNA rectifier, comprising: 1) establishing a mathematical model of nine switches based on the mathematical model of the VIENNA rectifier, obtaining the equality constraints between the duty cycle of the nine switches and the modulation wave; 2) establishing two equations satisfying the control voltage constraint through newly defined variables, and providing a general solution satisfying the equality constraint conditions; 3) obtaining six states based on the different directions of the three-phase current; obtaining inequality constraints under different states based on these six states; and obtaining the upper and lower limits of the free variables based on the inequality constraints under the six states; 4) solving for the compensation amount for neutral point potential balance control starting from the control equation for the capacitor neutral point potential control of the VIENNA rectifier. The modulation model and solution process of the VIENNA rectifier disclosed in this invention have a small computational workload, significantly reducing the computation time compared to the SVPWM modulation technology of three-level converters.

The application relates to the technical field of satellite working medium cryogenic storage, in particular to a satellite propellant working medium solid-state storage and partitioned phase change supply device and a manufacturing method thereof.The device comprises a storage box shell, a storage box cover plate, a heat exchange assembly, a storage box liquid port, a storage box gas port, a refrigerator interface, an electric connector and a flowmeter, wherein the storage box shell is in sealed connection with the storage box cover plate to form a closed working medium storage space; the heat exchange assembly is arranged in the interior of the storage box shell; the storage box liquid port and the storage box gas port are arranged on the storage box cover plate; the refrigerator interface is arranged on the storage box shell; the electric connector is arranged on the storage box shell; and the flowmeter is connected with the storage box gas port.The application adopts solid working medium storage, the storage pressure is low, is suitable for the storage box structure design of special-shaped space layout, enhances the flexibility of the structure and layout design of a satellite propulsion system, improves the space occupation ratio of the working medium storage box, and provides additional space for satellite load configuration.

The invention discloses a lithium battery equalization method based on improved fuzzy control, which aims at solving the problems of low single variable control precision and poor fixed universe adaptability in the existing equalization method, and comprises the following steps: firstly, dividing SOC into different intervals through battery OCV-SOC characteristic analysis, and preferentially carrying out voltage equalization in an extreme SOC interval to avoid overcharge and overdischarge; sOC equalization is preferentially carried out in the middle SOC interval so as to improve the energy transfer efficiency. A voltage and SOC dual fuzzy controller is designed, a variable universe fuzzy controller is introduced to dynamically adjust an input variable universe, the universe is expanded at the initial stage of equalization to accelerate response, and the universe is shrunk at the later stage of equalization to improve precision. And further designing a self-adaptive fuzzy controller, taking the SOC mean value and the equalizing current as input, and dynamically outputting a weight coefficient of a double-fuzzy controller, thereby realizing self-adaptive switching of the equalizing strategy under different SOC intervals. According to the invention, the equalization precision and efficiency are effectively improved, and the robustness and safety of the system are enhanced.

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 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 the field of multi-split air conditioning system technology, specifically to a disturbance control method for the outer loop electronic expansion valve of an air conditioning system. The problem this invention addresses is how to actively eliminate oil and refrigerant blockage and reduce exhaust temperature during defrosting or oil return processes through forced disturbance control of the outer loop electronic expansion valve. To solve this problem, this invention provides a control method comprising: acquiring the operating status parameters of the air conditioning system; determining whether the air conditioning system has triggered a disturbance program based on the status parameters; correcting the reference setting based on the exhaust temperature, compressor return superheat, and oil separator return oil temperature during the execution of the disturbance mode; determining whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program during defrosting and oil return modes; and automatically exiting the disturbance program when the air conditioning system exits the defrosting or oil return mode.

The invention provides a charging circuit and electronic equipment. The circuit may include: a first charge pump; a buck chopper circuit; wherein the step-down chopper circuit and the first charge pump are connected in series between a charging interface and an output node, the charging interface is used for being connected with a charger and receiving electric energy provided by the charger, and the step-down chopper circuit and the first charge pump are used for carrying out step-down processing on the electric energy received by the charging interface; the output node provides electric energy for a battery connected with the output node.