33results about How to "Reduce voltage ripple" patented technology

The invention relates to a compensation device and a compensation method of current filtering and the dead zone of a permanent magnet synchronous motor. The input end of a position sensor is connected with the output end of the permanent magnet synchronous motor, and the output end of the position sensor is connected with a rotating speed calculation module, a coordinate transformation module and a current inverse transformation module respectively. The output value of the rotating speed calculation module is used as the input of a speed ring PI adjuster. A current sensor inputs the detected two-phase current of the permanent magnet synchronous motor to the coordinate transformation module through a summation module, meanwhile the two-phase current is input into the coordinate transformation module, the coordinate transformation module transforms the coordinate of three-phase currents and then inputs the currents to an incremental kalman filter, and the output end of the incremental kalman filter is connected with the current inverse transformation module, a q-axis current ring and a d-axis current ring. The output end of a first current ring PI adjuster and the output end of a second current ring PI adjuster are connected with an inverter through a voltage inverse transformation module, the output end of the current inverse transformation module is connected with the input end of a dead zone compensation module, the output end of the dead zone compensation module is connected with the input end of the inverter, and the output end of the inverter is connected with the input end of the permanent magnet synchronous motor.

The invention relates to a light emitting diode driving method, suitable for driving a plurality of light emitting diode strings. Each light emitting diode string comprises a light emitting diode or a plurality of light emitting diodes connected in series. The light emitting diode driving method comprises the following steps of: acquiring the initial duty ratio of the driving current of each light emitting diode string in a frequency cycle so as to acquire the target accumulated glow brightness of each light emitting diode string; when the maximum value of the initial duty ratios of the driving currents of the light emitting diode strings in the frequency cycle is smaller than the frequency cycle, extending the duty cycle of the driving current of each light emitting diode string in the frequency cycle and enabling the accumulated brightness of the light emitting diode string in the extended duty cycle to be equal to the target accumulated glow brightness.

The invention discloses a multi-output switched capacitor converter applicable for multi-layer stacked loads. The multi-output switched capacitor converter comprises a first drive signal input end, asecond drive signal input end, N inner fly capacitors, N output capacitors, 2N branches and N interlayer loads, wherein the 2i-th branch, the (2i-1)-th branch, the i-th inner fly capacitor and the i-th output capacitor form a i-th power supply module; and the power supply modules are stacked in sequence. The multi-output switched capacitor converter is relatively low in voltage ripple and relatively high in conversion efficiency.

The invention discloses a high-frequency intermittent control system and method suitable for a bidirectional series resonant converter, including a first filter circuit, a first inverter / rectifier circuit, a resonant circuit, a high-frequency transformer, and a second inverter / rectifier circuit , the second filter circuit, voltage and current acquisition circuit, controller, drive circuit; the bidirectional series resonant converter can realize the buck and boost functions at the same time, and realize a wide working range, and all switches have achieved a wide range of zero current switching, reducing switching losses. Pulse control is added to the switching cycle and the pulse can be up to half of the resonant frequency, thus reducing the voltage ripple. The control strategy can make the system have linear power transmission characteristics, and the system characteristics are relatively simple and easy to operate.

The invention relates to a magnetic enhancing boosting double-excitation winding compound doubly salient electric-excitation generator. According to the doubly salient electric-excitation generator, tail ends of three phase windings A, B and C are open circuit windings, each phase winding is respectively connected with a diode and a capacitor, a dotted terminal of each phase winding is respectively connected with an anode of the diode, a cathode of the diode is connected with a positive electrode of the capacitor, the other end of the each phase winding is connected with a negative electrode of the capacitor, for three independent rectifier filter portions, according to the positive and negative relation of the capacitors, sequentially, a negative electrode of an A-phase capacitor Ca is connected with a positive electrode of a B-phase capacitor Cb, and a negative electrode of the B-phase capacitor Cb is connected with a positive electrode of a C-phase capacitor Cc. The doubly salient electric-excitation generator is characterized in that one end of a first excitation winding Lf1 is connected with a positive electrode of the A-phase capacitor Ca, the other end of the first excitation winding Lf1 is used as a positive electrode or a negative electrode of the generator to connect with a load, and two ends of the second excitation winding Lf2 are connected with a direct current excitation voltage source Uf.

The invention discloses an energy control method of a laser wireless power transmission system based on the efficiency optimization, and belongs to the technical field of laser wireless power transmission. An energy control strategy is mainly composed of an efficiency optimized control strategy and an energy management optimization strategy. In the efficiency optimized control strategy, under the premise that the output power of a photovoltaic array meets the load and storage battery power requirements, an efficiency optimized operating point of the system is searched by gradually reducing the pulse width of an input pulse current of a laser. In the energy management optimization strategy, the system efficiency and system charging power are taken as control objectives, the pulse width of an input current of the laser is further reduced to search for an optimum operating point of the system, the average output power of the laser is properly reduced in the searching process of the optimum operating point of the system to maintain the output voltage ripple of the photovoltaic array within a limited range thereof, the impact of excessive voltage ripple on the efficiency of the photovoltaic array is avoided, the rapid storage battery charging needs are thus met and meanwhile the system is allowed to operate at the efficiency optimized point.

The invention discloses a radio frequency energy collection system and a control method, wherein the radio frequency energy collection system includes a radio frequency antenna, a control circuit, a matching boost network, an RF-DC rectifier, a self-starting circuit, a hysteresis voltage comparator, a V DD terminal energy storage unit, V L End energy storage unit, switch S L , voltage detection circuit, V ST A terminal backup energy storage unit, a first energy conversion circuit, a second energy conversion circuit, an LDO voltage regulator circuit, a reference current source and a reference voltage generation circuit. The invention improves the structure of the existing circuit, optimizes the performance and innovates the structure of each circuit module, improves the sensitivity of the whole collection system, and can manage the stored energy at the same time. In addition, the invention has the characteristics of low power consumption, complete automation, and low voltage ripple.

The invention discloses a bidirectional series resonant converter and an improved intermittent sinusoidal modulation method thereof. Wherein the main circuit comprises switching networks, an LC series resonance network and an ideal transformer, the turn ratio of the ideal transformer is n: 1, the two switching networks of a primary side and a secondary side are full-bridge networks, and the primary side and the secondary side are each composed of four MOS tubes; the full-bridge port of the primary side is connected with the LC series resonance network, the resonance inductor is Lr, and the resonance capacitor is Cr. Pulse control is added in switching periods, each switching period of the modulation method comprises a sinusoidal modulation resonance period and a current-controllable intermittent period, and the modulation method not only has the sinusoidal modulation advantages of zero-current on-off and zero-backflow power, but also realizes linear power regulation in a wide power range. Voltage boosting and voltage reducing can be achieved through voltage gain, the wide working range is achieved, meanwhile, power loss is in direct proportion to the switching frequency, efficiency is irrelevant to loads, and efficient transmission of energy can be achieved.

The invention relates to a compensation device and a compensation method of current filtering and the dead zone of a permanent magnet synchronous motor. The input end of a position sensor is connected with the output end of the permanent magnet synchronous motor, and the output end of the position sensor is connected with a rotating speed calculation module, a coordinate transformation module and a current inverse transformation module respectively. The output value of the rotating speed calculation module is used as the input of a speed ring PI adjuster. A current sensor inputs the detected two-phase current of the permanent magnet synchronous motor to the coordinate transformation module through a summation module, meanwhile the two-phase current is input into the coordinate transformation module, the coordinate transformation module transforms the coordinate of three-phase currents and then inputs the currents to an incremental kalman filter, and the output end of the incremental kalman filter is connected with the current inverse transformation module, a q-axis current ring and a d-axis current ring. The output end of a first current ring PI adjuster and the output end of a second current ring PI adjuster are connected with an inverter through a voltage inverse transformation module, the output end of the current inverse transformation module is connected with the input end of a dead zone compensation module, the output end of the dead zone compensation module is connected with the input end of the inverter, and the output end of the inverter is connected with the input end of the permanent magnet synchronous motor.

The embodiment of the invention provides a charging circuit and electronic equipment. The charging circuit comprises a charging interface, a power management unit, a first voltage reduction module and a second voltage reduction module; the charging interface is used for connecting a charger and receiving a charging signal input by the charger; under the condition that the type of the charger is a first type, the charging signal is subjected to voltage reduction processing through the first path to obtain a first voltage signal, and the power management unit supplies power to a power utilization system according to the first voltage signal; under the condition that the type of the charger is a second type, the charging signal is subjected to voltage reduction processing through a second path to obtain a second voltage signal, and the power management unit supplies power to the power utilization system according to the second voltage signal so as to improve the total charging efficiency of the charging circuit; the first path comprises the second voltage reduction module; the second path includes the first voltage reduction module and a second voltage reduction module.

Provided is a direct type AC power converting device capable of reducing a rush current. A control unit (5) controls a current type converter (1) while a switch (S1) being ON, so that the voltage between an neutral phase input line (ACLn) having a resistor (R1) and any of input lines (ACLr, ACLs and ACLt) is subjected to a voltage doubler rectification and to a charge of clamp condensers (Cc1 andCc2). Thus, the clamp condensers (Cc1 and Cc2) are charged through the resistor (R1) so that the rush current can be prevented from flowing through them. Moreover, the terminal voltage of one set of the clamp condensers (Cc1 and Cc2) is higher than that of one set of condensers (Cr and Cs). Even if the clamp condensers (Cc1 and Cc2) and the condensers (Cr and Cs) are electrically connected at an ordinary running time, the rush current can be prevented from flowing from the condensers (Cr and Cs) to the clamp condensers (Cc1 and Cc2).

The invention discloses a permanent magnet generator with a heater, which is composed of a shaft, a heater fan, a generator shell, two rotor iron cores, a permanent magnet, two sets of armature windings and a stator iron core, wherein the tail end of the shaft is fixed with the heater fan; two disc-shaped rotor iron cores are sequentially fixed in the middle of the shaft; rotor poles convex along the axial direction are arranged in opposite directions of the two rotor iron cores; the middle of the two rotor iron cores is the stator iron core; two end surfaces, facing the rotor iron cores, of the stator iron core are provided with stator poles; each stator pole is provided with one armature winding; and the permanent magnet is embedded at the fan-shaped root of the stator iron core. According to the permanent magnet generator with a heater, reliable integration of the heater and the generator can be realized; as the disc-type motor structure is adopted, the stator-rotor contact area is large, and the specific power of the motor is high; the rotor has no excitation source and can rotate reliably and at a high speed; and the two stators can form a complementary six-phase winding, and voltage fluctuations are thus reduced.