34results about How to "Reduce input current ripple" patented technology

The invention relates to direct current (DC) step-up power conversion technology and discloses a current-type multi-resonance DC converter. The current-type multi-resonance DC converter comprises a square-wave current source generator, a multi-resonance network and a rectification filtering output unit which are sequentially connected in series, and is characterized in that: the multi-resonance network comprises a transformer, a parallel resonant inductor, a parallel resonant capacitor and a serial resonant inductor, wherein the serial resonant inductor is connected with a primary side of the transformer; the rectification filtering output unit comprises a diode rectifying circuit and a filtering capacitor which is connected with an output end of the diode rectifying circuit in parallel.

The invention discloses a secondary type high-gain boosting converter with switched capacitors and a coupled inductor. The secondary type high-gain boosting converter comprises a direct-current input power source, a first inductor, a first diode, the coupled inductor, the first capacitor, a second diode, a switching tube, a third diode, the second capacitor, a fourth diode, the third capacitor, a fifth diode, the fourth capacitor, a sixth diode, the fifth capacitor, a seventh diode, an eighth diode, the first output capacitor, the second output capacitor and a load. According to the secondary type high-gain boosting converter, a driving circuit and a main circuit are grounded together and share only one switching tube, a control circuit is simple, the higher output voltage gain is obtained under the low duty ratio, the input current and output voltage ripples are reduced, the voltage stress and turn-on losses of a switching element are reduced, meanwhile, the turn ratio of the coupled inductor needed by the circuit is small, and the saturation problem of a magnetic core component is avoided. The secondary type high-gain boosting converter is quite suitable for occasions of low-voltage input and high-voltage output.

The invention provides an interleaving-based capacitor clamped high-gain boost converter comprising a capacitor clamped circuit and an interleaving Boost structure which comprises a first inductor, asecond inductor, a first switch tube, a second switch tube, a main diode, a main capacitor, an input source and a load. The interleaving Boost structure is connected with the capacitor clamped circuitvia a first node, a second node and a third node to generate three-level square waves which are connected to the capacitor clamped circuit, so that a clamping capacitor can obtain a backward voltagetwo times an output voltage of the interleaving Boost structure; the clamping capacitor is embedded to a negative terminal of the load to obtain a boost converter topology with the gain being 3/(1-D).The converter has the advantages that clamping capacitance generated during work of the capacitor clamped circuit can be organically fused in the interleaving Boost structure, so that the boost converter has the advantages of high gain, small input current ripples and low voltage stress of devices.

The invention discloses a power output control method and a power output control system for a fuel cell power generation array system. According to the present invention, by collecting the output voltages and the inductance current signals of each DC/DC circuit in each fuel cell system, low-frequency ripple control is stabilized to obtain a switch-on time and a switch-off time, such that a switchcontrol signal is generated so as to carry out DC/DC converter control; the control system comprises a data acquisition module, an outer loop voltage control module, a slope calculation module, a switch control module and a modulation and demodulation module; the slope transformation of the inductance current under the switch control is calculated to obtain a duty ratio, and the switch signal is controlled by the modulation and demodulation module so as to carry out DC/DC converter control; the performance of the DC/DC converter is improved by stabilizing the low-frequency ripple control; andthe multi-stack fuel cell uses the parallel topology structure and controls the mean current, such that each stack in the fuel cell array can output the required power.

The invention provides a high-gain Boost converter based on a three-winding coupled inductor and a working method of the high-gain Boost converter. The high-gain Boost converter comprises a Boost unit, an auxiliary Boost unit, a voltage doubling unit and a low ripple unit; the Boost unit comprises a primary winding, a first switching tube, a second switching tube and a fourth capacitor and a fifthcapacitor which are connected in series; the positive electrode of a power supply is connected with the non-dotted terminal of the first winding; the dotted terminal of the primary winding is connected with the drain electrode of the first switching tube and the source electrode of the second switching tube; the source electrode of the first switching tube and the source electrode of the second switching tube are connected to the two ends of the fifth capacitor respectively; and the negative electrode of the power supply is connected with the source electrode of the first switching tube. Theproblem of low efficiency of the Boost converter in the prior art is solved.

The invention relates to single-stage multi-input high frequency link inverter adopting multi-winding simultaneous/time-sharing power supply current. The circuit structure of the inverter is formed byconnecting multiple high-frequency inverter circuits and a common output cycle conversion and filter circuit in series through a multi-input single-output high-frequency transformer, wherein the high-frequency inverter circuits are isolated from one another and provided with input filters and storage inductors; input ends of the multi-input single-output high-frequency transformer are connected in one-to-one correspondence with output ends of the corresponding high-frequency inverter circuits; the output end of the multi-input single-output high-frequency transformer is connected with the input end of the output cycle conversion and filter circuit. The inverter has the characteristics of realizing simultaneous/time-sharing power supply of the multiple input sources and output and input high-frequency isolation, sharing the common output cycle conversion and filter circuit, adopting concise circuit and single-stage power conversion, being high in voltage matching capacity, high in power density, high in conversion efficiency and broad in application prospect and the like, multiple input sources are common-ground or not common-ground, and a key technology is provided for distributedpower supply systems with intermediate or small capacity for combined power supply based on multiple new energy resources.

The invention relates to a differential mode inductor-free staggered parallel Vienna rectifier and a control circuit thereof. The rectifier comprises a network side filter circuit and a staggered parallel Vienna rectifier circuit, wherein the staggered parallel Vienna rectifier circuit comprises a three-phase coupling inductor, first to twelve power switch tubes, and first to twelve power diodes.The invention further discloses a control circuit of the rectifier. The network side filter circuit suppresses nearby harmonics of switch frequency; leakage inductance of the coupling inductor replaces differential mode inductance, so that volume and weight of a converter are lowered; the staggered parallel manner increases capacity of the converter, lowers current stress of the switch tube, and reduces input current ripples and output voltage ripples, thereby reducing capacitance of a bus capacitor and volume and weight of a magnetic element. The differential mode inductor-free staggered parallel Vienna rectifier has characteristics of low deformation rate of total harmonics, small volume and weight, small input current ripples and small output voltage ripples.

The invention discloses a dual-frequency modulation method for a quasi-Z source three-level direct current boost converter. The dual-frequency modulation method is applied to a fuel cell electric vehicle and comprises the steps that the expression of the time occupied by four power switch states in a duty cycle is acquired; the modulation degree of the drive signal of a power switch is set to 1/3<m<1, and a volt-second balance relation between inductor L1 and L2 in a continuous current mode is acquired; the voltage stress expression of each capacitor is acquired through the expression of timeand the volt-second balance relation, and then voltage gain is acquired; the voltage stress of each capacitor is acquired according to the voltage stress expression and the voltage gain; and the voltage stress withstood by all turned off power devices is acquired. According to the invention, the voltage gain of a topology is improved without changing the number of topological devices; the advantage of low voltage stress of original power devices is retained; and the topology is suitable for voltage conversion occasions of fuel cells.

Relating to a direct-current converter, the invention discloses a double-Y source high step-up ratio DC-DC converter, and aims to solve the problems that an existing Y-source step-up converter is discontinuous in input current and overlarge in starting current, and the step-up ratio cannot meet requirements. The double-Y source high step-up ratio DC-DC converter comprises a first Y-source conversion sub-circuit and a second Y-source conversion sub-circuit, and the working modes of the first Y-source conversion sub-circuit and the second Y-source conversion sub-circuit comprise a straight-through working mode and a non-straight-through working mode.

The quasi-switched capacitor type high-gain DC-DC converter is characterized in that one end of a first inductor L1 is connected with the positive electrode of a DC input voltage source Vin, and the other end of the first inductor L1 is connected with the negative electrode of a second capacitor C2, the positive electrode of a first diode D1 and the drain electrode of a first MOS tube S1; the source electrode of the first MOS tube S1 is connected with the negative electrode of the first capacitor C1 and the positive electrode of the third capacitor C3, the negative electrode of the first diode D1 is connected with the positive electrode of the second diode D2, and the positive electrode of the first capacitor C1 is connected with the common end of the first diode D1 and the second diode D2. The negative electrode of the second diode D2 is connected with the positive electrode of a second capacitor C2, the drain electrode of a second MOS tube S2 and the positive electrode of a fourth diode D4, the negative electrode of the fourth diode D4 is connected with the positive electrode of a third capacitor C3, and the negative electrode of the third capacitor C3, the source electrode of the second MOS tube S2 and the negative electrode of the third capacitor C3 are all connected with the negative electrode of a direct current input voltage source Vin. Two ends of the third capacitor C3 are used for parallel connection with a load and supplying power to the load.

The embodiment of the invention discloses a voltage conversion circuit and method, and a terminal, and the circuit comprises a first boost circuit and a second boost circuit, which are connected in parallel. The first boost circuit is used for receiving a direct-current voltage and a first switching signal in a first time period of each period, and storing the direct-current voltage according to the first switching signal. The second boost circuit is used for receiving the direct-current voltage and the first switching signal in a second time period of each period and storing the direct-current voltage according to the first switching signal; and the first boost circuit is also used for receiving a second switching signal and the DC voltage in the second time period, and converting the received DC voltage and the stored DC voltage into a driving voltage according to the second switching signal so as to drive a load to work.

The invention discloses a switched reluctance motor torque ripple and bus current ripple suppression method. According to the method, the flux linkage characteristic and the torque characteristic of the switched reluctance motor need to be obtained through off-line measurement. A total torque reference value is output by a speed proportional-integral controller, and a reference torque value of each phase is calculated by a torque distribution function. And according to the position and current information at the moment k and the position information stored at the moment k-1, calculating flux linkage and current information at the moment k + 1 in combination with an optimal switching vector calculated at the previous moment, and carrying out delay compensation. On the basis, position information at the k + 2 moment and flux linkage current information under an available switching vector are predicted, then a table is looked up to obtain torque and inverter input current values under each switching state, the torque and the inverter input current values are substituted into a cost function, the operation state with the minimum cost function value serves as a switching signal, and the switching signal is applied to a control power converter; therefore, the effect of suppressing the torque ripple and the bus current ripple at the same time is achieved. The effectiveness of the method is verified through simulation, the control logic of the method is simple, the torque ripple and bus current ripple suppression effect is obvious, and the impact of bus current on the supporting capacitor is effectively reduced.

The invention discloses an armature reconfiguration type charger sliding-mode control method for an electric automobile. The method comprises the steps that firstly, battery charging current is sampled, charging current deviation obtained through charging current negative feedback passes through a PI controller and an amplitude limiting controller, and given charging voltage uo* is obtained; battery charging voltage is sampled, and charging voltage deviation obtained through charging voltage negative feedback passes through the PI controller to be multiplied with sampled rectifier bridge output voltage to obtain motor winding flowing-through current given value; and finally, motor winding flowing-through current is sampled, and is subjected to independent sliding-mode control, and a control signal of a three-phase inverter is obtained to control the three-phase inverter. Alternating-current side unit power running is achieved, the content of AC side input current ripple waves is effectively reduced, it is ensured that in the charging period, the automobile is in the static state all the time, and robustness and anti-interference capacity of the system are greatly improved.