86results about How to "Reduce RMS" patented technology

The invention relates to a high power factor DCM Boost PFC converter comprising a main power circuit and a control circuit. The main power circuit comprises an input voltage source vin, an EMI filter, a diode rectification circuit RB, a Boost inductor Lb, a switch tube Qb, a diode Db, an output capacitor Co and a load RLd. The high power factor DCM Boost PFC converter is characterized in that the control circuit adopts an output signal which adopts duty ratio as changing rule to drive the switch tube Qb. Adopting the varying duty ratio control, the high power factor DCM Boost PFC converter can improve the PF value to about 1 in the AC input voltage range of 90-265 V, increase the inductance capacity, obviously decrease the inductive current ripple, obviously reduce the effective value of the inductive current and correspondingly reduce the effective value of the current of the switch tube, has high input power factor and small output voltage ripple and contains less input current harmonic waves. The conduction loss of the high power factor DCM Boost PFC converter is reduced, and the efficiency is improved.

The invention discloses a Boost type isolated DC / DC converter and a control method of the Boost type isolated DC / DC converter. The Boost type isolated DC / DC converter is composed of a primary side circuit, an auxiliary side circuit, an ideal transformer and a two-port passive network, wherein the primary side circuit is composed of a full-bridge unit circuit where interleaved Boost circuits are integrated, the auxiliary side circuit is composed of a rectifying circuit, the two-port passive circuit is composed of an inductor and a capacitor and is an energy transmitting unit, and the transformer is used for achieving isolation and transformation. Two interleaved Boost input inductors are connected in the middles of two bridge arms of the full-bridge unit circuit, and therefore the gain range of the isolated DC / DC converter is widened, and input current ripples are reduced; frequency-fixed PWM control is adopted, the duty ratio D of a bridge arm switching tube is controlled, and therefore the output voltage can be adjusted. The Boost type isolated DC / DC converter and the control method have the advantages of being wide in input voltage range, small in input current ripple, fixed in switching frequency, capable of allowing soft switching to be achieved, small in switching loss and the like, and are particularly suitable for renewable energy power generation systems and other systems.

The invention discloses a gas injection type parallel gap device. The protection device belongs to the field of lightening protection gap for power transmission lines of alternating-current and direct-current electric power systems. The device is connected with the two ends of a power transmission line insulator chain in parallel, under a lightening stroke, the device is broken down before the insulator chain can be broken down, and thus the insulator chain and the corresponding power transmission line can be protected; moreover, a high-speed high-voltage gas flow can be generated fast and acts on arcs to restrain formation and development of the arcs, the arcs are extinguished in a transient state, and thus the lightning trip-out rate and the lightening accident rate of an electric power system are reduced. The gas injection type parallel gap device comprises arc-control devices on the grounding side and the wire side, fixing devices and parallel spiral fittings installed at the two ends of the insulator train of the line. The arc-control device on the grounding side and the arc-control device on the wire side respectively comprise an arc extinguishing powder storage chamber, an arc air-termination ring, an insulating gas generation chamber, an arc spray channel and the like. With the device, the stability of the electric power system is improved, the on-load action frequency of a breaker is effectively reduced, the service life of electric power equipment such as a transformer is prolonged, and production, operation and maintenance cost is very low.

The invention discloses a control device used for improving the PF value of a DCM Buck PFC converter. The control device comprises a main power circuit and a control circuit. The main power circuit comprises an input voltage source vin, an EMI filter, a diode rectifier circuit RB, a Buck inductor Lb, a switch tube Qb, a diode Db, an output capacitor Co and a load RLd. The control circuit comprises an output voltage feedback control circuit, an input voltage feedforward circuit, a second multiplier and a sawtooth wave comparing and switch tube drive circuit. Input voltage feedforward and output voltage feedback are introduced, so that the duty cycle of the converter changes according to a certain rule in a power frequency cycle, and the PF value is improved to close to 1 in the AC input voltage range between 90V and 264V. The control device provided by the invention has the advantages of small output voltage ripple, small switch tube conduction loss, reduced required diode stress and the like.

The invention provides a power supply short circuit protection circuit comprising a voltage detection module, a switching control module, and a time-delay holding module. The voltage detection module is used for detecting a voltage related to the short circuit of an output terminal of a power supply. Whether the output terminal of the power supply is short-circuited is judged based on the detected voltage. When that the output terminal of the power supply is short-circuited is judged, a control signal is output to a terminal which controls a control IC to output or stop outputting a PWM signal. According to the power supply short circuit protection circuit, no matter if the control IC of a power circuit has a short circuit protection function, the control IC can be reliably enabled to stop outputting the PWM signal to achieve the purpose of short circuit protection, and the effective value of an output current when the output of a power supply is short-circuited can be reduced.

The invention discloses a current effective value minimizing control method for a bidirectional half-bridge tri-level DC (Direct Current)-DC converter. Three controlled quantities in a topological structure of the bidirectional half-bridge tri-level DC-DC converter are controllable, namely a primary side bridge arm middle point voltage duty ratio D1, a secondary side bridge middle point voltage duty ratio D2 and a phase shift angle Dalpha between primary side bridge arm middle point and secondary side bridge arm middle point voltage; minimized control of the current effective level is achieved under the premise that power required for transmission load is satisfied. According to the current effective value minimizing control method for a bidirectional half-bridge tri-level DC (Direct Current)-DC converter, D1, D2 and Dalpha is coordinately controlled, the current effective value of a transformer is minimum under the condition that the power required for the load is satisfied, copper loss of a magnetic element in a circuit and conduction losses of a switch tube are reduced, meanwhile switch tubes in the circuit can achieve zero-voltage conduction within the integral transmission power range, and switch loss of a power device is effectively reduced.

The invention discloses a parallel envelope tracking power supply which comprises a switching converter, an AB type linear amplifier and a full feed-forward control circuit, wherein a Buck converter or a synchronous rectification Buck converter is used as the switching converter; the full feed-forward control circuit comprises a current sampling circuit, a current regulator, a proportional differential feed-forward circuit, a phase inverter, an adder, a PWM (Pulse Width Modulation) modulator and a driving circuit; the current sampling circuit is used for detecting the output current of the AB type linear amplifier, comparing the output current with a current reference signal and feeding an error signal into the current regulator; and an output signal of the proportional differential feed-forward circuit is processed by the phase inverter, the output signal of the proportional differential feed-forward circuit and an output signal of the current regulator are fed into the PWM modulator after being subjected to additive operation by the adder, and then a driving signal of the switching converter is obtained by the driving circuit. The structure is mainly used for the switching Buck converter and the AB type linear amplifier; an output voltage full feed-forward control method is adopted; and the system efficiency is improved.

The present invention relates to a multiple output flyback converter having a switch regulated output circuit (5). To avoid a second communication interval, due an output voltage in this secondary controlled output that is lower what is implied by its number of winding turns, the inductance of this circuit is increased. This can preferably be done by increasing the leakage inductance of the winding (6) in the regulated circuit.

The invention discloses a deepwater robot power supply system, which comprises a water surface power supply device and an underwater repeater, wherein the water surface power supply device is arrangedon a ship and processes low-voltage alternating current provided by an on-board electric generator arranged on the ship to obtain corresponding high-voltage direct current; and the underwater repeater is used for converting the high-voltage direct current transmitted from the water surface power supply device, and transmitting electric energy obtained by conversion to a deepwater robot. Comparedwith an existing power supply system that three-phase alternating current is directly adopted to supply power to a motor in the deepwater robot, the system disclosed by the invention is changed into two-line power supply from three-phase power supply, in addition, only active power required by the motor in the deepwater robot needs to be transmitted, so that the amount of the traverses of a wholeumbilical cable is reduced, meanwhile, the diameter of the traverse is reduced, and the weight and the cost of the umbilical cables are greatly lowered.

The invention discloses a multi-level converter topology suitable for a medium-high voltage occasion and a control method. The multi-level converter topology is composed of a first blocking capacitor,a first phase-shifting inductor, a first isolation transformer, a primary side multi-level conversion unit and a secondary side conversion unit. The primary side multi-level conversion unit is formedby connecting a first conversion unit and a second conversion unit in series. The alternating-current output end of the first conversion unit and the alternating-current output end of the second conversion unit are connected with the first blocking capacitor, the first phase-shifting inductor and the primary side of the first isolation transformer in series to form the primary side of the multilevel converter. On the premise of the same power device, the series structure of the two conversion units greatly improves the working voltage level of a single module, and reduces the size and cost ofthe system. By adopting the control method provided by the invention, the transformer current under the condition that the input and output voltages are not matched is reduced, the converter loss isreduced, and DC voltage balance of the first conversion unit and the second conversion unit is maintained.

The invention discloses a switch converter and a control method thereof. The switch converter comprises a positive input power source, a positive output voltage source, a power source common ground, switch tubes Q1 to Q4, an inductor L1 and a capacitor C1, the drain of the switch tube Q1 and the drain of the switch tube Q3 are connected to the positive input power source, the source of the switchtube Q1 and the drain of the switch tube Q2 are connected to one end of the inductor L1, the source of the switch tube Q3 and the drain of the switch tube Q4 are connected to the other end of the inductor L1, the source of the switch tube Q4 is connected to one end of the capacitor C1, and the source of the switch tube Q2 and the other end of the capacitor C1 are connected to the power source common ground. The inductor L1 can be rapidly demagnetized under a relatively high ratio of input voltage to output voltage, current waveform of the inductor L1 is converted from triangular into quadrangular, and high-efficiency high-frequency work of the switch converter is realized.

The invention provides a control device and a control method, which can detect current offset amount under the moving state of the AC motor conducting phase control of voltage, and can inhibit or eliminate the current offset amount through controlling a voltage waveform. A control device of the alternating current motor controls the voltage waveform on the condition of considering the current offset amount of the AC motor (9) having current detection units (97U-97W) and a phase detection unit (95). The control device comprises voltage phase setting portion (12), an offset detecting unit (11), a switch control unit (13) and a waveform switching unit (16).

The present invention relates to a charge holding-based switching device driving circuit. The charge holding-based switching device driving circuit includes a transformer primary side H bridge and a secondary side secondary driving circuit; the H bridge comprises a first MOS switch tube, a second MOS switch tube, a third MOS switch tube and a fourth MOS switch tube; and the secondary side secondary driving circuit includes a fifth MOS switch tube, a sixth MOS switch tube and a switch. With the charge holding-based switching device driving circuit of the invention adopted, driving loss can be effectively decreased, the efficiency of power and electric power converters can be improved, and therefore, the defects of existing power semiconductor device driving circuit, such as large driving loss and low anti-interference ability, can be eliminated.

The invention relates to a low-input voltage bridgeless staggered voltage-multiplying power factor correction device. A bridgeless staggered voltage-multiplying power factor correction (PFC) circuit consists of four power metal oxide semiconductor field effect transistors (MOSFET), two inductors and five diodes, and aiming at low-input voltage and high-power application occasions, the circuit conversion efficiency can be improved, and the circuit corrugation can be reduced further. The device integrates a diode rectifier bridge with the PFC circuit, has inherent voltage-multiplying function and can reduce an effective value of current. Therefore, the conduction loss can be reduced, the circuit corrugation is reduced, the efficiency is improved, and the device is suitable for the low-voltage and high-power application occasions.

The invention discloses a single-stage AC-DC converter mode smooth switching and power factor correction control method, and belongs to the technical field of high-frequency switching power supply directions in power electronics. According to the method, a dual-active-bridge DC-DC converter is controlled by using four modes which can be smoothly switched; the control variables of each mode comprise the duty ratio d1 of the primary side, the duty ratio d2 of the secondary side and the phase shift angle between the primary side and the secondary side, and the control variables can be obtained through the critical ZVS condition of each mode; and mode switching does not need to be judged according to a load power value. According to the invention, by taking the effective value of the leakage inductance current of a transformer as an optimization target, the transformation ratio of the transformer is optimized to improve the conversion efficiency of the converter; and by taking the leakageinductance current of the transformer as an optimization target, the transformation ratio of the transformer is optimized, so that the voltage conversion gain of the DAB converter is no longer smallerthan 1 all the time.

The invention discloses a control method based on a cascade bidirectional DC-DC converter. The method is relatively simple; and by means of controlling a capacitance voltage through a control unit to be equal to product of a first power voltage and a turns ratio N of a transformer coil, the method can realize soft switching of all switching devices of the cascade bidirectional DC-DC converter in a full-load range. Meanwhile, while transmitting the same power, effective value of resonant inductor current of the cascade bidirectional DC-DC converter can be minimal. Overall efficiency of the cascade bidirectional DC-DC converter is improved.

The invention discloses a control method and system for a DCDC (Direct Current to Direct Current) converter. The system comprises a sampling device, a first computer, a second computer and a pulse width modulation signal generating unit. The method comprises the following steps of: (S1) sampling a bus voltage Ubus, an inverter alternating current voltage Uac(t) and an alternating current Iac (t) of the DCDC converter; (S2) figuring out a given value Ubusref of the bus voltage according to the inverter alternating current voltage Uac(t) and the alternating current Iac (t); (S3) figuring out an error value between the given value Ubusref of the bus voltage and the bus voltage Ubus; and (S4) generating a pulse width modulation signal according to the error value and outputting the pulse width modulation signal to an MOS tube base of the DCDC converter. Therefore, the bus voltage Ubus is jittered, so that an envelope line of the input current Iin is changed into a straight line and the conduction losses of an MOS tube and a diode in the DCDC converter are reduced.

The invention belongs to the field of relays, and specifically relates to an energy-saving relay. The relay comprises a relay body and an energy-saving circuit serially connected with a coil in the relay body, wherein the energy-saving circuit comprises a voltage stabilizing filter sampling module, an IC (Integrated Circuit) power management module, an IC pulse control module and an MOS (Metal Oxide Semiconductor) transistor on-off circuit module; the voltage stabilizing filter sampling module is used for adjusting the input voltage to be less than 5V; the IC power management module is used for converting the input voltage to stable 5V voltage and supplying the 5V voltage to the IC pulse control module; the IC pulse control module is used for controlling the on / off and on / off time of the energy-saving circuit; and the MOS transistor on-off circuit module is used for converting output voltage into input voltage. The relay has the advantages that after contacts of the relay are completely attracted, maintaining voltage is supplied to the relay in a pulse mode, so that the effective value of the external input voltage is greatly reduced, the energy loss when the relay is maintained is reduced, and energy is saved.

The invention discloses a five-degree-of-freedom modulation method for a dual-active bridge DC-DC converter, the modulation method is used for a DAB converter, and the modulation method comprises the following steps: S1, determining the working mode of the DAB converter based on the conduction sequence and time length of switches in the DAB converter; and S3, with the minimum inductance current peak-to-peak value as an optimization target, solving the minimum peak value current in each working mode under the KKT condition, then obtaining a global current peak-to-peak value minimum strategy through comparison, wherein it is worthy that the inductance current peak-to-peak value expression is simple and can be regarded as another form of root-mean-square current, and the optimization complexity can be greatly simplified. The DAB converter has a smaller inductive current effective value, almost all switching tubes can realize soft switching, and the conduction loss and the turn-on loss of the DAB converter can be reduced to the greatest extent; in addition, the method also keeps the simplicity of control, and is easier to implement.

The invention relates to an electronic ballasting method of a gas discharge lamp; a start high frequency impulse is generated by a control unit and a high power chopper of a power conversion unit is driven by the control unit; after alternating current is rectified the full-wave, a pulsating direct current is processed by high frequency chopping of high power chopper and by transformation, after passing through a high frequency inductor, a high pressure trigger is started by the obtained pulsating direct current and a start high frequency alternating current is outputted. A power supply high frequency impulse is produced in the control unit and high frequency alternating current energy is provided continuously in a new frequency by the power conversion unit. The invention also provides an electric ballast of the gas discharge lamp, comprising a control unit and a power conversion unit; the control unit is composed of an impulse generator, a pulse distributor, a power driver, a high frequency transformer and a adjustment protection unit; the power conversion unit is composed of a rectifier, a high frequency chopper, a high frequency transformer, a high frequency inductor, a high frequency current transformer and a high pressure trigger. The invention solves the problems of the reliability and stability of the electronic ballast and the energy saving.

The invention discloses a modulation method for suppressing common mode voltage of a matrix converter. The method comprises the following sequential steps of performing singular value decomposition on space vector forms of all on-off state matrixes of the matrix converter, dividing all on-off states of the matrix converter into three types based on the singular value decomposition, preferentially selecting the on-off states with small corresponding common mode voltage values in modulation matrix calculation and an on-off sequence of the matrix converter by utilizing an equivalent relation between different types of on-off states in the matrix converter, and reducing a change rate of output common mode voltage by optimizing the on-off sequence. The modulation method reduces the amplitude and the change rate of the output common mode voltage of the matrix converter, reduces the amplitude and an effective value of the common mode voltage, and ensures low input / output waveform harmonic content of the matrix converter.

The invention discloses a full bridge controllable power generating system employing a doubly-salient generator. The full bridge controllable power generating system includes a prime motor, the doubly-salient generator, a rectification power circuit and a generator controller. The prime motor drives the doubly-salient generator to rotate. The magnitude and the on-off of exciting current of the doubly-salient generator are controlled by the generator controller. One ends of windings of the doubly-salient generator are connected in a star shape so as to form a winding midpoint while the other ends of the windings are led out to connect with a compensation capacitor in series and then to connect with the input terminal of the rectification power circuit. The output terminal of the rectification circuit is connected with a load through a filtering capacitor and supplies power for the load. According to the invention, the output power of the motor can be increased, the voltage adjustment rate can be reduced and phase current control becomes quicker and more flexible. The invention discloses a control method of the full bridge controllable power generating system employing the doubly-salient generator.

The invention discloses a bridgeless power factor correction (PFC) circuit, relates to the technical field of power electronics and is used for solving the problems of relatively low conversion efficiency and power density of the bridgeless PFC in the prior art. The circuit comprises an AC power supply, a boost inductor, a self-coupling transformer, at least two groups of switch bridge arms and abus capacitor, wherein each group of switch bridge arm comprises a bridge arm middle point and at least two bridge arm end points, the self-coupling transformer comprises at least two output ends, oneend of the boost inductor is connected with the AC power supply, the other end of the boost inductor is connected with an input end of the self-coupling transformer, each output end of the self-coupling transformer is connected with the bridge arm middle point of one of the two groups of switch bridge arms, and the bridge arm end points of each group of switch bridge arm are connected with different end points of the bus capacitor.

The invention discloses a soft switching Buck converter and a control method thereof. The two ends of an energy storage inductor L1 of an existing synchronous Buck circuit are connected with a circuitin parallel, wherein the circuit is formed by connecting an inductor L2, a one-way conduction device and a switching tube in series. According to the control method, the switching tube is conducted after the inductor L1 is demagnetized for a set time; an inductor L2 starts to be excited, the inductive current IL2 of the inductor L2 is increased when the inductor L2 is excited, the inductive current IL1 of the inductor L1 is decreased when the inductor L1 is demagnetized, and IL2 is enabled to be greater than IL1 at the moment when the synchronous switching tube is turned off; and the currentof IL2-IL1 charges and discharges output capacitors of the main power switching tube and the synchronous switching tube, so that the voltage at one end of the inductor L1 is enabled to be close to Vin, soft switching of the main power switching tube of the Buck converter in a continuous mode is realized, and the Buck converter works in a high-frequency, high-efficiency, high-density and low-EMI manner.

The invention provides a voltage-stabilizing system for regulating voltage fluctuation of a power grid. The voltage-stabilizing system comprises a critical load module, a non-critical load module, a bidirectional critical load power spring, a plurality of voltage detection modules, a plurality of current detection modules and a plurality of phase detection modules, wherein the bidirectional critical load power spring is connected with the critical load module and the non-critical load module in series, and is connected to the power grid by means of a transmission lead wire. The invention further provides an operation method of the voltage-stabilizing system for regulating voltage fluctuation of the power grid. The interactive voltage-stabilizing system has the beneficial effects that: the interactive voltage-stabilizing system does not require the participation of an energy storage device, but compensates energy at the non-critical load side to the critical load by means of bidirectional energy flow, so as to maintain stability of voltages at two ends of the critical load; since the interactive voltage-stabilizing system can compensate the voltage of an arbitrary phase angle, the frequencies and phase positions of the voltages at two ends of the critical load can be corrected; and since the interactive voltage-stabilizing system provides voltage compensation to the critical load directly, the interactive voltage-stabilizing system has low impedance and voltage division requirements for the transmission line, has large regulation range and low cost, provides reasonable voltage and energy management for the future distributed power generation system, and is conductive to the large scale application of new energy power generation.

The invention provides a CRM buck-flyback PFC converter with fixed frequency control. The CRM buck-flyback PFC converter comprises a main power circuit, an input voltage digital feedforward circuit, an output voltage differential circuit, a feedback circuit, a state determination circuit, a driving signal generation circuit, a comparison circuit and a multiplication circuit. According to the invention, the input voltage digital feedforward circuit, an input voltage comparison circuit and a gating circuit are introduced to achieve a double-fixed-frequency control mode, so that the switching frequencies of the switching tubes of the converter at the Buck stage and the Flyback stage are respectively kept at different constant values.