35results about How to "Solve the problem of current sharing" patented technology

The invention discloses a parallel structure and a control method for a photovoltaic power generation grid-connected inverter and belongs to the technical field of renewable energy sources. A topological circuit structure of the photovoltaic power generation grid-connected inverter is divided into a parallel structure of single-phase voltage type pulse-width modulation (PWM) inverters and a parallel structure of three-phase voltage type PWM inverters; and in the control method, an outer ring regulator of a control circuit of the parallel voltage type PWM inverters is independent based on a power grid voltage-oriented vector control technology in a control mode of voltage outer ring and current inner ring so as to form a common unified outer ring regulator; control strategies of various inverters are simplified into single closed loop current control so as to achieve the consistency of energy flow directions of the parallel voltage type PWM inverters and avoid ring current; and the parallel current sharing of the voltage type PWM inverters is realized. Therefore, multiple modules of the voltage type PWM inverters are connected in parallel to realize high-power modularized large-scale application.

The invention relates to a voltage conversion device in the electronic power system in order to simplify the loop structure, save switch devices and solve the issues of bidirectional flow of the power as well as the equal flows in the low voltage stages. The device includes 1-4 phases. Each phase is independent with the identifical structure composed of the high voltage stage, the isolation stage and the low voltage stage. The high voltage stage includes 2-30 identical power conversion modules in serial. The isolation stage includes the part of the modulation/demodulation in high frequncies etc. The low voltage stage includes the power conversion module. Comparing with the foreign scheme, the number of the devices is reduced one-third, and the cost also is reduced.

The invention discloses a large-capacity battery converter and control method thereof. The converter of the invention comprises several branch single stage type DC/AC converter modules parallel to one another. Each battery cluster (Battery Cluster BC) converges energy to an AC bus via each branch single stage type DC/AC converter module to be transformed in voltage in order to connect to an AC grid or to operate independently with load. The invention solves the circular current and uniform current problems brought by serial and parallel connection of the battery cluster, and adopts the technology of module combination and alternate balance to effectively improve the system efficiency under low power and power quality at the AC and DC sides and to realize balanced use of the battery cluster. Each battery branch can conduct intelligent charge and discharge management and the control function and the protection function are configured independently to ensure the largest availability of the system. The invention has simple structure, small volume, small energy loss, easy modularization, high reliability, small output harmonic wave, good system expansibility and low requirement to insulating ability of the converter and can operate with reduced capacity when the unit is in failure. The control method of the large-capacity battery converter of the invention is convenient and simple in operation and easy in realization.

The invention discloses a parallel flow air conditioner, comprising a compressor, a compressor muffler, a four-way valve, an indoor unit, a capillary tube assembly, a top tube of an upper fluid collection tube, an upper fluid collection tube, a flat heat exchange tube and a lower fluid collection tube, wherein a first end of the lower fluid collection tube is provided with a gas-liquid separator, the gas-liquid separator is connected with a check valve, the check valve and the first end of the upper fluid collection tube are connected with the same connector of the four-way valve in parallel. The invention also discloses a processing method of the parallel flow air conditioner. In the invention, the parallel flow technology is adopted, cooling and heating can be realized, and the problems that the flow distribution is uneven, the heat exchange efficiency is low, the volume is large and the cost is high can be solved.

The invention discloses a parallel structure of a voltage source type PWM (Pulse Width Modulation) rectifier and a control method of the rectifier, belonging to the technical field of power electrical application. A topology circuit structure of the voltage source type PWM (Pulse Width Modulation) rectifier includes a parallel structure of a single-phase voltage source type PWM (Pulse Width Modulation) rectifier and a parallel structure of a three-phase voltage source type PWM (Pulse Width Modulation) rectifier. The control method is a vector control technology based on power system voltage orientation, which comprises the following steps of: by use of voltage outer ring and current inner ring control way, separating out an outer ring voltage regulator of a control circuit of the parallelvoltage source type PWM (Pulse Width Modulation) rectifier to form a common uniform voltage regulator, outputting a unique outer ring control voltage, simplifying a control policy into single closed ring current control to solve consistency problem of energy flow direction of the parallel voltage source type PWM(Pulse Width Modulation) rectifier so as to avoid generation of ring current and to provide technical supports for high power, modularization and large-scale application of the multi-module parallel connection of the voltage source type PWM (Pulse Width Modulation)rectifier.

The present invention relates to a parallel structure of three-phase multi-level PWM converters which are suitable for distributed power supplies, and systems for grid-connected power generation with renewable energies, charging and discharging and energy storage therefor and the like. Then present invention includes more than two three-phase multi-level PWM converters and control circuit units thereof, a digital signal processor and a three-phase alternating current power supply circuit; and further includes a common unified voltage regulator, the unified voltage regulator consisting of a voltage sampling circuit, a voltage sensor, a third adder and an external loop voltage PI regulator, the voltage sampling circuit being connected in parallel to a load RL. The advantages of the present invention are as follows: the energy flow direction consistency problem of each three-phase multi-level PWM converter when operating in parallel is solved, the generation of a loop current is avoided, and at the same time the problem of equal current when each three-phase multi-level PWM converter operates in parallel is solved. The present invention is suitable for scenarios in which high power and scaled power electronics conversion is applied.

The invention provides a multi-phase interleaved Boost convertor. An output end of a generator is rectified through a rectifying circuit and is connected with input ends of Boost circuits and auxiliary power supply respectively, wherein the auxiliary power supply supplies working voltage to a sequence circuit and a control circuit; a signal output end of the sequence circuit is connected with a signal input end of the control circuit; the signal output end of the control circuit is connected with signal input ends of the Boost circuits; and the Boost circuits output voltage for use by load. By the scheme of carrying out voltage stabilization and current balancing on a plurality of Boost circuits by the plurality of interleaved Boost circuits and a voltage-stabilizing loop, the problems of high-power output and current balancing are solved; the current balancing effect is relatively good; a special current balancing circuit does not need to be designed; the input voltage range is wide; and relatively high power factor and efficiency can be obtained.

The invention relates to a parallel IGBT module copper bus bar installation structure. The copper bars comprises a short-connected copper bar and a switched copper bar, wherein the switched copper bar is fixedly arranged on the short-connected copper bar; at least one IGBT module is arranged on the short-connected copper bar; and a slotted hole is formed on a short-connected copper bar and between the installation positions of the switched copper bar and the IGBT module on the short-connected copper bar. The parallel IGBT module copper bar installation structure can well solve the problem of uniform flow of each IGBT module and is compact and simple.

The invention discloses a multi-input parallel and multi-output parallel power converter. The power converter comprises a switch network, an inductor-capacitor combination module, a transformer module, a rectifier module and a filter module, the switch network, the inductor-capacitor combination module, the transformer module, the rectifier module and the filter module are connected in order; theswitch network comprises multiple parallel identical switching circuits; the transformer module comprises a plurality of transformer sets, the transformer sets comprises a plurality of same transformers in which the primary windings are connected in series, and the transformer sets are in one-to-one correspondence connection with the switch circuit; the rectifier module comprises a plurality of rectifying circuits, and the output of the rectifying circuits are connected in parallel; the secondary windings are connected in series of the corresponding transformers in the transformer sets, and the secondary windings are connected in series and then are connected with the corresponding rectifying circuits in the rectifier module for rectification.

The present invention includes a crystallizer mounted on the dummy head on the dummy seat, the upper portion of crystallizer is equipped with flow distribution plate which can possess hot top action. It is characterized by that the bottom portion of the described flow distribution plate is equipped with more than two fow-distributing holes correspondent to every crystallizer. The adoption of said invented equipment can produce aluminium alloy flat ingot, can solve the flow equalization problem in the course of casting process, the cast aluminium ingot does not produce crack, so that the same-level hot top casting process can be adopted in the production of aluminium alloy flat ingot.

The invention provides a spray tower with a gas flow equalizing device. The spray tower with the gas flow equalizing device comprises a spray tower, a gas inlet is formed in the lower part of the spray tower; a gas outlet is formed in the top of the spray tower; the spray tower further comprises a circular flow guide cylinder and a conical flow guide cylinder located above the circular flow guidecylinder. An annular flow equalizing area is formed between the circular flow guide cylinder and the tower wall of the spray tower, the gas inlet is formed in the tower wall of the spray tower corresponding to the annular flow equalizing area, the conical guide cylinder is located above the circular guide cylinder, the diameter of the upper end of the conical guide cylinder is larger than that ofthe lower end of the conical guide cylinder, and a gap is formed between the lower end of the conical guide cylinder and the circular guide cylinder. According to the spray tower, gas enters the towerbody of the spray tower, and can only enter the spray area from the gap under the flow equalization effect of the circular guide cylinder. The circular guide cylinder and the conical guide cylinder have buffering and flow equalizing effects so that the gas is more uniform in the spray area of the tower body, the influence of incoming flow change on flow equalization is small, and the flow equalization problem of the gas in the horizontal direction is effectively solved.

The invention relates to a secondary inversion parallel main circuit. The circuit comprises a main transformer T1, and the main transformer T1 comprises a first secondary side winding and a second secondary side winding. The first secondary side winding is connected with a first secondary inverter circuit; the second secondary side winding is connected with a second secondary inverter circuit; a center tap of the first secondary winding and a center tap of the second secondary winding penetrate through the magnetic ring L2 in a staggered manner, then are connected with each other and serve asan output negative end of the secondary inversion parallel main circuit; the output end of the first secondary inverter circuit is connected with the output end of the second secondary inverter circuit and serves as the output alternating current end of the secondary inverter parallel main circuit. According to the invention, a current-sharing inductance wiring method that the main transformers T1with the same iron core and two groups of identical secondary sides and the two center taps of the two groups of identical secondary sides penetrate through the magnetic ring in a staggered manner and magnetic circuits are mutually counteracted is adopted, so the current and voltage waveforms of the upper and lower groups of secondary sides are completely consistent.

The invention discloses an elastic sub-module and a modular crimping type semiconductor module. The elastic sub-module comprises a conducting strip, an insulating elastic piece and a conducting plate, the conducting strip is a bent conducting strip which is bent to be provided with a plurality of grooves, the conducting strip is clamped at the upper end of the insulating elastic piece through the grooves, and the lower end of the insulating elastic piece is connected with the conducting plate; the modular crimping type semiconductor module comprises a module collector plate, a chip sub-module, a module emitting polar plate and an elastic sub-module; the chip sub-module comprises a chip, a collector conductor and an emitter conductor; and the module collector electrode plate, the collector electrode conductor, the chip, the emitter electrode conductor, the elastic sub-module and the module emitter electrode plate are sequentially connected from top to bottom. The module has the advantages that the thermal resistance can be further reduced and the power density and the current level of the module can be improved through a chip modularization form; and the modularization of the chip subunits can also reduce the material cost and reduce the processing procedures.

The invention belongs to the technical field of integrated circuits, and particularly relates to a charge pump parallel current sharing circuit based on duty ratio control. According to the invention, the equivalent impedance of the charge pump is changed mainly by adjusting the duty ratio, and then the current sharing of the output current during the parallel operation of the charge pump is realized, specifically, the parallel current sharing is realized by enabling the charge pump power tube to work according to the output duty ratio through the duty ratio adjusting module connected with the charge pump. The scheme can be popularized to a charge pump framework with any conversion ratio. According to the scheme, the duty ratio is changed, and the frequency is not changed. Therefore, from the perspective of EMI, the energy spectrum is concentrated on the switching frequency and the harmonic frequency, and almost no energy exists in the range below the switching frequency, so that the design of system EMI is facilitated. The invention provides an analog implementation mode and a digital implementation mode.