32results about How to "Reduce output current ripple" patented technology

The invented equipment is in use for controlling current in load coil of electromagnet bearing. The switching power amplifier includes circuit for generating signal of pulse width modulation (PWM), light coupling isolation and switching drive circuit, main circuit of full bridge and current testing circuit. Based on error signal formed from specified signal of current and feedback signal of current, the switching power amplifier carries out PWM. Through light coupling isolation and switching drive circuit, completed PWM signal controls and turns to On / Off of four pieces of power switch tube on two bridge arms of main circuit of full bridge directly. The invention lowers wastage in electromagnet bearing caused by current ripple.

The invention discloses a half-period operating current distortion suppression system and method for a double-buck grid-connected inverter. The invention establishes that the buck unit works in the current continuous mode and the half-period working state of the buck unit in the dual-buck topology. The different intervals of the current discontinuous mode, and establish the corresponding relationship between the switching time of the continuous current mode and the discontinuous mode and the amplitude of the incoming current. In the discontinuous current mode, according to the nonlinear relationship between the voltage gain of the buck unit and the duty ratio, the output of the current loop regulator is corrected for the equivalent linearization of the modulated wave, so that the gain and the output of the regulator to the bridge arm voltage Consistent when the current is continuous. The invention reduces the current ripple and current conduction time by reducing the duty cycle, avoiding the current distortion problem caused by the inductor current ripple in the traditional control, so that the half-period working double-buck inverter is not only efficient and reliable, but also Realizing low harmonics of incoming grid current is more conducive to the application of dual-buck topology in grid-connected inverters.

The invention relates to a staggered single-cycle control complementary current generator and a control method thereof. The invention has the advantages of small current tracking error, high tracking speed, fixed switching frequency, and the like and remarkably decreases the ripple component of the output compensation current in a staggered ripple cancellation mode. The staggered single-cycle control complementary current generator comprises a three-phase inverter bridge I and a three-phase inverter bridge II, the output ends of the two three-phase inverter bridges I and II are respectively connected in series with a current transformer group I and a current transformer group II and then respectively connected with a three-phase inductor I and a three-phase inductor II, the output ends of the three-phase inductors I and II are connected in parallel and then connected with a three-phase compensated power line, the three-phase inverter bridges are respectively connected with pulse driving devices which are respectively with corresponding current detection units I and II, synchronous pulse generating units, voltage parameter arithmetic elements and instruction current arithmetic elements, the current detection units are connected with the respective current transformer groups, and the two arithmetic elements are connected with corresponding detection units.

The invention discloses a three-level hysteresis current tracking inverter and a control method of the three-level hysteresis current tracking inverter. An three-level inverter bridge output end is connected with an inductor in series mode and then serves as an output end of the three-level hysteresis current tracking inverter, each voltage detecting unit respectively detects voltage between a zero level supporting point of a three-level inverter bridge and a three-level output end of the inverter, detected results are respectively fed to each driving control unit, a current detecting unit detects three-level output current of the inverter, detected results are respectively fed to each hysteresis comparison unit, three-level command current signals are respectively fed to each hysteresis comparison unit and each driving control unit, output ends of each hysteresis comparison unit are connected with corresponding driving control units, output ends of each driving control unit are connected with corresponding units, and output ends of each driving unit are connected with driving signal input ends of the three-level inverter bridge. The device and the control method can perform hysteresis tracking control on output current of the three-level inverters and have the advantages of being high in tracking accuracy, fast in speed, good in real-time and the like.

The invention discloses a high-gain boost DC converter for fuel cell power generation. The high-gain boost DC converter comprises an input power source Vin, wherein the positive pole of the input power source Vin is connected with an inductor L1; the inductor L1 connected with the drain of a switch S1 and a capacitor C1; the capacitor C1 connected with the anode of a diode D1, a capacitor C2 and an inductor L2; the inductor L2 connected with a load RL and a capacitor C4; the capacitor C2 connected with the cathode of a diode D2 and the anode of a diode D3; and the diode D3 having the cathode connected with the load RL and the capacitor C3, wherein the negative pole of the input power source Vin is connected with the source of the switch tube S1, the cathode of the diode D1, the anode of the diode D2, the capacitor C3 and the capacitor C4. The high-gain boost DC converter for fuel cell power generation has high voltage gain, low device voltage stress and low input and low output currentripples, is suitable for the field of fuel cell power generation, and can prolong the service life of the full cell while improving the low-voltage direct current of the fuel cell.