32results about How to "High accuracy of current sharing" patented technology

The invention provides a parallel current sharing circuit of a charging module of an electric automobile charger, comprising a charger monitoring unit and at least one charging module which are connected in parallel, wherein the charging modules are linked in parallel; the charger monitoring unit is connected with the charging modules through communication signal lines; and the charging modules are connected through average current signal lines, and connected with a grid alternating current end and a power battery direct current end of the electric automobile respectively. By using the current sharing circuit disclosed by the invention, the sampling feedback coefficient of the output voltage of the module is adjusted according to the differential value between a module charging current sampling signal and average current signals of all the parallel modules, thus the charging voltage and the charging current of the module are further adjusted to reach the purpose of load-sharing current in parallel of every charging module. The parallel current sharing circuit has relatively high current sharing precision and current sharing dynamic responding speed, is beneficial to improving the reliability and the maintainable performance of the charger and better satisfies the charging requirement of the power battery of the electric automobile.

The invention discloses a microgrid system and a control method. The microgrid system comprises a plurality of energy storage converters connected in parallel between a DC bus and an AC bus; the AC sides of the energy storage converters are connected in parallel through an AC bus and then connected with the grid-connected or parallel control cabinet; the grid-connected or parallel-connected control cabinet receives an instruction of a coordination control device of the microgrid and controls the microgrid to work in a grid-connected mode or an off-grid mode; the grid-connected or parallel-connected control cabinet obtains a current component reference value of a current inner loop through outer loop control, and sends the obtained current component reference value to each energy storage converter connected in parallel; and each energy storage converter performs current inner loop operation according to the received current component reference value to obtain a driving signal for driving the switching tube of the energy storage converter to be switched on and switched off. According to the method, the information processing speed of the microgrid during information processing can beincreased, Meanwhile, the problems of respective sampling of each energy storage converter in the microgrid energy storage system and imbalance of outer loop calculation errors can be effectively eliminated.

The invention discloses a low-frequency offset three-phase multi-inverter parallel operation control method under a micro-grid island. Each inverter and an LC filter thereof under the micro-grid island are controlled to be voltage-controlled current sources; a reference frequency of fundamental current output by each inverter is a rated value; a reference phase can be obtained through a disturbance observation-based maximum output voltage tracking method; a reference amplitude of the fundamental current output by each inverter is obtained through common bus-based feedback proportional control; distribution of output current of each inverter according to the capacity proportion can be achieved by reasonably setting a proportion coefficient and a voltage amplitude on a micro-grid bus is controlled to be close to the rated value; a harmonic current reference output by each inverter is obtained through bus harmonic voltage feedback control; and quasi proportional resonant control in a static coordinate system is adopted as current tracking control of each inverter. According to the low-frequency offset three-phase multi-inverter parallel operation control method under the micro-grid island, the influence of the difference between line parameters on equal division of output current of each inverter is overcome, the frequency of the voltage in the micro-grid operation process is relatively stable and the influence of voltage frequency fluctuation on a load is reduced.

The invention discloses a current equalization circuit for a multi-module shunt-wound power supply. The current equalization circuit comprises a sampling resistor R1, an operational amplifier N1 and a divider resistor R2, and further comprises a diode V1, an operational amplifier N4, a divider resistor R10, a divider resistor R11, a divider resistor R12, a grounding resistor R13 and a feedback resistor R14, wherein one end of a divider resistor R4 is connected with the positive input terminal of the operational amplifier N1, and other end of the divider resistor R4 is grounded. When the current equalization circuit works, the module with the maximum output current, in a plurality of shunt-wound modules, automatically serves as a main module, and other modules are slave modules; voltage errors of all the modules are sequentially regulated to correct unbalanced current distribution of a load; when the gross power of a system has a larger margin in comparison with the load, the failure of a single module can not influence the normal operation of the shunt-wound power supply; and as a redundant design of the shunt-wound power supply is added, the product reliability is effectively improved.

The invention provides a current equalizing circuit of a remote direct-current power supply. Via double control of software and hardware, a sampling error of current is eliminated; via revising optimization of software, current equalizing precision among modules is improved, and output voltage of a system is stabilized. The technical scheme includes that a CPU (central processing unit) control end is added, via comparison amplifying of equalized current calculated by a CPU and sampled current, and via the double control of the software and the hardware, the sampling error of the current is eliminated, the current equalizing precision among the modules is improved, and the output voltage of the system is stabilized. Compared with the prior art, the current equalizing circuit of the remote direct-current power supply has the advantages that higher current equalizing precision is realized, the output voltage of the system is stabilized, stability of the system is enhanced, and service life of the system is prolonged.

The invention relates to an isolated high-power LED driving power supply with multichannel output and current sharing and a realization method thereof. The driving power supply comprises a half-bridge CLL resonance network, a current sharing network, and an LED lamp load circuit, the LED lamp load circuit comprises 2N channels of LED lamp loads, and the half-bridge CLL resonance network realizes current-sharing output of the 2N channels of LED lamp loads through the current sharing network, wherein N is a natural number greater than and equal to 2. According to the driving circuit with multichannel output and current sharing, primary windings of transformers are connected in series and are combined with secondary current-sharing capacitors of the transformers, current-sharing output of four channels or any 2N channels of same or different numbers of LED loads can be realized, the circuit is simple, the efficiency is high, and the current-sharing precision is high.

The invention discloses a multipath direct current power supply circuit which comprises an alternating current source, a first power supply unit and a second power supply unit. Each of the power supply units comprises at least two paths of power supply branches. A first output terminal of the alternating current source is connected with a first terminal of each path of power supply branch in the first power supply unit respectively. A second output terminal of the alternating current source is connected with a first terminal of each path of power supply branch in the second power supply unit respectively. Second terminals of all power supply branches in the first power supply unit and the second power supply unit are connected. The circuit also comprises blocking capacitors between the first output terminal and the first terminal of each path of power supply branch in the first power supply unit respectively, and blocking capacitors between the second output terminal and the first terminal of each power supply branch in the second power supply unit respectively The power supply circuit has the advantages of high efficiency, low cost and good current sharing performance.

The invention discloses a hardware current sharing device and a working method thereof, the device comprises a plurality of current sharing ICs, the plurality of current sharing ICs is connected through a current sharing bus, and any current sharing IC comprises a current comparison module, a current tracking module and a gain feedback module. The method comprises the steps of obtaining an output current of a current PSU; obtaining output currents of other PSUs in the multi-node server; comparing the plurality of output currents, with the plurality of output currents including the output current of the current PSU and the output currents of other PSUs, defining the PSU with the maximum current as a master module, and defining the other PSUs as slave modules; controlling the slave modules to adjust the output current according to the difference between the output current of the master module and the output currents of the slave modules; acquiring feedback current in a transconductance mode according to the comparison result of the multiple output currents and the output currents adjusted by the slave modules; and outputting the feedback current to LLC half-bridge resonance in the PSUs. According to the invention, the PSU current sharing sensitivity and current sharing precision can be effectively improved, and the stability of a server system is improved.

The invention discloses a multipath direct current power supply circuit, which comprises an alternating current source and at least two paths of power supply branch circuit, wherein the first output end of the alternating current source is connected with the first input end of each path of power supply branch circuit through a common capacitor; and the second output end of is connected with the second input end of each path of power supply branch circuit. The invention also discloses another multipath direct current power supply circuit. The two power supply circuits are high in efficiency, low in cost and good in flow equalization performance.

A current-sharing method based on UCC29002 relates to the technical field of power electronics. By adopting the working mode of a maximum current automatic current-sharing method in the invention, users can only adjust values of a sense resistor RSHUNT, amplification factor ACSA of a current detection amplifier, an adjusting resistor RADJ and error amplifier compensators REAO and CEAO according toa specific parallel system. The invention has simple peripheral circuit, high current-sharing precision, high load adjustment rate, good dynamic response, which provides a new solution for parallel operation of a DC-DC converter with +/- Sense terminal, suitable for wide promotion and application.

The invention relates to a current-sharing control method for a flexible direct-current power transmission direct-current converter of an offshore wind power plant, and belongs to the technical fieldof wind power. The control method comprises the following steps: performing PI on the difference between a voltage reference value and an actual value of a low-voltage side direct-current bus, then performing amplitude limiting to obtain output current reference value of a preceding-stage converter of each direct-current converter module, subtracting the actual value from the output current reference value of the preceding-stage converter, performing PI to obtain a driving signal of the preceding-stage converter to achieve the functions of boosting and stabilizing the voltage and transmissionpower of the low-voltage side direct-current bus; taking a high-voltage side current average value of all direct-current converter modules as a high-voltage side current reference value iok * of eachdirect-current converter module, subtracting an actual value iok from the high-voltage side current reference value iok *, and performing PI to obtain a current-sharing compensation amount icok; subtracting an actual value from an output voltage reference value of a preceding-stage converter of each module, performing PI, then performing amplitude limiting ,adding icok, subtracting iok, and performing PI to generate a driving signal of a backward-stage converter to achieve the functions of high-voltage side current sharing, boosting, power transmission and grid connection.