48results about How to "Improve current sharing effect" patented technology

A synchronous soft-start networking control strategy of EMU parallel auxiliary converter is disclosed. When that first auxiliary converter is put into bus bar, the non-first auxiliary converter synchronously completes networking and network connection during the first amplitude soft-start process. The specific scheme is as follows: fast networking logic, busbar fast tracking logic and PQ droop control strategy. The fast networking logic includes the identification of the first and non-first auxiliary converter, the busbar fast tracking logic includes phase, frequency and amplitude tracking, and the PQ droop control strategy includes the introduction of correction factor K. A synchronous soft-start networ control strategy of auxiliary converter of EMU can realize fast and reliable automaticnetwor of auxiliary converter in EMU emergency traction mode. In the normal mode of EMU network, the networking time can be significantly shortened. Therefore, the invention can ensure that the EMU can be started in a prescribed time under various working conditions, and provides a powerful guarantee for the stable and reliable operation of the EMU.

The invention relates to a smoke gas purification device by a semidry process, which is provided with an independent desuperheating tower, comprising a reaction tower provided with an smoke inlet box, a smoke gas outlet, a venturi tube type tower wall arranged on a tower bottom, a water injector arranged on the tower wall and a nozzle for lime dry powder and revert dust; and the smoke gas outlet is connected with an inertia separator, an activated carbon mixer, a bag-type dust remover and a draught fan. The invention is characterized in that the invention is also provided with the desuperheating tower which is provided with a boiler smoke gas inlet manifold, a single-stage water injector, an ash bucket with an ash hole and a gas flue; the gas flue of the desuperheating tower is connected with the smoke inlet box into one unit. The boiler smoke gas disperses within the two towers for cooling, thereby improving the adaptability of a system to a load; the boiler smoke gas particularly can be cooled down urgently to a set temperature in the desuperheating tower; and the reaction tower can be humidified only by evaporation with a little water to complete a deacidifying reaction and remove dioxin, thereby avoiding the disadvantages of scale formation on the tower wall of the prior reaction tower and bag burning of the bag-type dust remover, guaranteeing a sustaining and stable smokepurification process and having the advantages of good purification effect and low energy consumption.

The invention discloses a half-bridge power semiconductor module, comprising: a semiconductor chipset located at the bottom layer; a low-sensitivity composite busbar located at the top layer, and the two sides of the low-sensitivity composite busbar are respectively extended with AC interfaces and positive and negative layer interfaces, The low-sensitivity composite busbar includes the negative layer busbar, the positive layer busbar and the AC layer busbar arranged in layers; several busbar groups connected in parallel with each other in the middle layer, among which, the bottom end of each busbar group and the semiconductor chip The corresponding semiconductor chips in the group are connected, and the top busbars of each busbar group are connected to the corresponding busbars of the low-inductance composite busbars. The semiconductor chipset is the main functional part of the power module. The AC interface and the positive and negative layer interfaces of the low-inductance composite busbar are used as the external interface of the main circuit of the power module. The busbar group realizes the conductive connection between the low-inductance composite busbar and the semiconductor chipset. , taking into account the current sharing between the busbar group and the chips of the semiconductor chipset, and improving the low inductance and current sharing of the power module.

The invention belongs to the technical field of droop control of DC converters, relates to a droop control method of a DC converter with a function of secondary adjustment of adaptive impedance, and aims to solve the problems that distributed generating unit cable impedance difference causes poor droop current homogenization effect to the DC distributed power supply system and the DC micro grid based on droop control and the parallel DC converters is low in steady state and dynamic current homogenization precision. The method has the advantages that the steady state and dynamic current homogenization precision of the parallel DC converters in the distributed DC power supply system and the DC micro grid based on droop control is improved; parameters, such as voltage, current and droop coefficient, of the parallel converters are transmitted in real time through low-speed communication, the droop coefficient is adjusted in self-controllers of the parallel converters, and finally external characteristic impedances of the parallel converters are equalized; droop curves are subjected to shifting adjustment, and bus voltage drop caused by droop control is improved.

The invention provides a current equalizing method and device of a current transformer. The method comprises the following steps of detecting a port voltage and an internal induction current of a power sub-module; adjusting a carrier signal of the power sub-module with maximum internal induction current and / or the power sub-module with minimum internal induction current according to a symbol of the port voltage of the power sub-module; and controlling an output current of the corresponding power sub-module according to the adjusted carrier signal. Therefore, excessive large current and excessive small current are prevented from occurring in the output current of the current transformer, current equalizing of the current transformer is achieved, and the current equalizing effect is improved; and the carrier signal of the power sub-module with maximum / minimum internal induction current is only adjusted each time, and thus, the steps of current equalizing of the current transformer are simplified.

The embodiment of the invention discloses a current-sharing method, device and system of a power module. The method comprises the following steps: acquiring a voltage between an emitter of an IGBT module of each power module in parallel connection and an AC output terminal of the IGBT module in the current pulse duration of the PWM pulse; adjusting the pulse duration of the next PWM pulse of eachpower module according to the acquired voltage, and performing current sharing on the power module in parallel connection. Through the current-sharing method, device and system disclosed by the embodiment of the invention, the pulse duration of the next PWM pulse of each power module is automatically adjusted according to the voltage between the emitter of the IGBT module of each power module in parallel connection and the AC output terminal of the IGBT module in the current pulse duration of the PWM pulse, an operation of using a current-sharing electric reactor or a circulation suppression electric reactor is avoided, and then the cost can be reduced and the current-sharing effect is improved.

A crimping type power switch module, characterized in that it includes: an upper end plate, a lower end plate, a PCB board, and at least one subunit between the upper end plate and the lower end plate, the subunit includes: a supporting frame, and a The conductive metal sheet, the first molybdenum sheet, the power switch chip, and the second molybdenum sheet are arranged from bottom to top inside the support frame; the support frame includes a metal frame and an insulating layer wrapped outside the metal frame. The invention avoids the technical problem of severe current interference between multiple bullet element chips in the crimping device, increases the safe working area of ​​the power device, and improves the current equalization performance among each bullet element.

The invention discloses a medicine material flow equalizing device for a propellant extruder. The device comprises an outer cylinder, a mold body, a piston and a rubber pad, wherein the piston consists of a piston body, a piston rod and a rubber disc; a groove is formed in the bottom of the piston body; a ventilation hole communicated with the groove is formed in the top surface of the piston body; the rubber disc is fixed at the bottom of the piston body to enable a groove cavity of the groove to become an air storage chamber; inner holes of the outer cylinder are sequentially a pore diameterD1 section, a pore diameter D2 section and a pore diameter D3 section from top to bottom, and D2 > D1, D3 = D1; a plurality of medicine outlet holes with the same shape and size are formed in the mold body, through holes with the same position, number, size and shape as the medicine outlet holes on the mold body are formed in the rubber pad, and each through hole on the rubber pad is respectivelyaligned with the corresponding medicine outlet hole on the mold body when the rubber pad is fixedly connected with the mold body; and the piston body is mounted in the pore diameter D1 section, the rubber pad is mounted in the pore diameter D3 section, the mold body covers the bottom of the outer cylinder and is fixedly connected with the wall of the outer cylinder, and the pore diameter D2 section and the top surface of the rubber pad form a medicine material extrusion cavity.

The invention relates to an optimal control method for a parallel power supply system based on the minimum column sum of an equalizing standard deviation matrix. According to the method, firstly, the standard deviation matrix is built to determine output current when the equalizing property of the system is the optimal; secondly, a centralized controller determines an output current value under the condition that the equalizing property is the optimal through obtaining the output current of online power supply modules in real time and obtains an optimal value of the number of the online power supply modules; thirdly, the centralized controller controls the number of the online power supply modules in real time and ensures that the number is the optimal value or close to the optimal value; and whether running power supply modules meet the requirements or not is judged and optimal dispatching control is carried out. Under the target of ensuring that the equalizing property of the parallel power supply system is close to an optimal working point, i.e., the number of the online running power supply modules is the optimal, optimal dispatching on the online power supply modules with poor equalizing property and standby power supply modules is carried out by calculating the standard deviation of the output current of each power supply module and equalizing target value deviation, so that the target that the parallel power supply system and the online power supply modules work near the optimal point of the equalizing property is achieved.

The invention provides a tube box structure, a shell and tube heat exchanger and an air-conditioner. The tube box structure comprises a shell (1) and a refrigerant liquid inlet connection pipe (2) connected to the shell (1). A liquid equalizing cavity (3) is formed in the shell (1). A flow equalizing pipe (4) and a first flow equalizing plate (5) located on the outlet side of the flow equalizing pipe (4) are arranged in the liquid equalizing cavity (3). The flow equalizing pipe (4) is connected to the outlet position of the refrigerant liquid inlet connection pipe (2). According to the tube box structure, the flow equalizing effect of the heat exchanger can be improved, and the heat exchange efficiency of the heat exchanger is also improved.