39results about How to "Improve output voltage quality" patented technology

The invention belongs to the technical field of converters and discloses a power frequency ripple suppression method and device for an LLC converter in order to overcome the defects existing in the existing LLC converter power frequency ripple suppression technology. In the method, a voltage loop is used as main control, and a ripple loop is added and used as compensation control. By the adoption of the power frequency ripple suppression method and device, in the mode that ripple control and voltage loop control are combined, the gain of a power frequency doubling band of a system is increased, and the adjusting capacity of the system on the power frequency band is improved; consequently, the beneficial effects that ripples are reduced and the quality of output voltages is improved are achieved.

The invention discloses a PFC dual-full-bridge-based intelligent sine wave voltage conversion circuit. The intelligent sine wave voltage conversion circuit comprises an input rectifying and filtering unit, a PFC voltage boosting unit, a full-bridge DC-to-DC isolation converter unit, an inversion phase reversal unit and a filtering inductor, wherein the full-bridge DC-to-DC isolation converter unit comprises a first switching tube, a second switching tube, a transformer, a first rectifying bridge, an eighth switching tube, a ninth switching tube and a first electrolytic capacitor; the inversion phase reversal unit is connected to the output end of the full-bridge DC-to-DC isolation converter unit for performing inversion conversion on the output voltage of the full-bridge DC-to-DC isolation converter unit and then outputting an alternating current; the front end of the filtering inductor is connected to the output end of the inversion phase reversal unit while the back end of the filtering inductor is connected with a load; and the filtering inductor is used for filtering high-frequency pulse and providing power frequency sine alternating current for the load. By adoption of the PFC dual-full-bridge-based intelligent sine wave voltage conversion circuit, the output voltage quality can be improved, and the high-frequency pulse in the output signal can be filtered.

The invention discloses a PFC forward full-bridge-based intelligent type correction filtering voltage conversion circuit. The PFC forward full-bridge-based intelligent type correction filtering voltage conversion circuit comprises an input unit, a PFC voltage boosting unit, an isolation type two-transistor forward converter and an inversion phase reversal unit, wherein the isolation type two-transistor forward converter comprises a first switching tube, a second switching tube, a first fly-wheel diode, a second fly-wheel diode, a second rectifying diode, a transformer, a filtering inductor, and a first electrolytic capacitor; the drain of the first switching tube is connected to the output end of the PFC voltage boosting unit; the source of the first switching tube is connected to the first end of a primary winding of the transformer; the second end of the primary winding of the transformer is connected to the drain of the second switching tube; the source of the second switching tube is connected with a front leading end; the gate of the first switching tube and the gate of the second switching tube are used for connecting the same PWM signals; and the inversion phase reversal unit is used for performing inversion conversion on the output voltage of the isolation type two-transistor forward converter and outputting an alternating current. By adoption of the intelligent type correction filtering voltage conversion circuit, the PF value and the output voltage quality can be improved.

The invention discloses a method and a device for processing an output voltage ripple of a charger. The method comprises a step of timely collecting a practical bus voltage value and a practical output voltage value; a step of comparing a preset bus voltage reference value with the practical bus voltage value to obtain an output voltage ripple adjusting value; a step of comparing a preset output voltage reference value with the practical output voltage value to obtain an output voltage adjusting value; and a step of obtaining a drive adjusting value according to the output voltage ripple adjusting value and the output voltage adjusting value and adjusting the practical output voltage value according to the drive adjusting value. According to the method provided by the invention, the output voltage ripple of the charger can be limited within an allowable range by repeatedly carrying out the abovementioned steps, and influences of the bus voltage ripple on the output voltage ripple are prevented under a precondition that the hardware cost is not increased.

The invention relates to the field of distribution transformers and provides an alternating parallel nine-speed transformer on-load voltage regulation circuit capable of polarity conversion, and the circuit comprises a main winding, a polarity conversion switch, a voltage regulating winding, a transition switching unit, a rated voltage branch and five voltage regulating branches. The circuit provided by the invention sets a polarity conversion switch between the main winding and the voltage regulating winding, and realizes positive and negative pressure regulation by adjusting the independentcontact connecting end of the polarity conversion switch. One ends of the respective voltage regulating branches are respectively connected to two end taps and each of the intermediate taps of the voltage regulating winding; the other ends are adjacently staggered and connected in parallel in two groups and respectively connected with two input ends of the transition switching unit; the input endof the rated voltage branch is connected to the taps of the output end of the main winding, and the output of the rated voltage branch is connected to the output end of the voltage regulating circuit.The circuit has the beneficial effects of reducing the on-off frequency of the on-off switch, increasing the service life of the corresponding pressure regulating switch, and during the voltage-regulating process, varying the transition voltage with the pressure regulating gear position with no shifting pressure regulation required.

The invention relates to an island microgrid bus voltage imbalance and harmonic compensation method and system, and the method is characterized in that the method comprises the following steps: 1) selecting an inverter with the maximum capacity in a microgrid as a main inverter, and enabling the rest inverters in the microgrid to serve as slave inverters; 2) acquiring current in a load of the microgrid, and performing component separation on the acquired load current; 3) generating a reference current instruction value of the slave inverter according to each component of the load current; 4) obtaining a current tracking error of the slave inverter; 5) enabling the obtained current tracking error to pass through a slave inverter current inner loop controller to generate a PWM modulation signal; 6)enabling the slave inverters to control the turn-off of the IGBT according to the generated PWM modulation signal so as to control the output compensation current of the slave inverter, therebycompleting island microgrid bus voltage imbalance and harmonic compensation. According to the invention, the method can be widely applied to the microgrid power quality management research field.

The invention discloses a PFC flyback full-bridge-based intelligent modified-wave voltage conversion circuit, which comprises an input unit, a PFC booster unit, a flyback isolation converter unit and an inverse inverter unit, wherein the flyback isolation converter unit comprises a first switch tube, a transformer, a first rectifier diode and a first electrolytic capacitor; a first end of a primary winding of the transformer is connected to an output end of the PFC booster unit; a second end of the primary winding of the transformer is connected to a drain of the first switch tube; a source of the first switch tube is connected to front-end ground; the first end of a secondary winding of the transformer is connected to an anode of the first rectifier diode; the second end of the secondary winding of the transformer is connected to rear-end ground; a cathode of the first rectifier diode is taken as an output end of the flyback isolation converter unit; and the inverse inverter unit is used for carrying out inverse conversion on output voltage of the flyback isolation converter unit and then outputting AC. According to the PFC flyback full-bridge-based intelligent modified-wave voltage conversion circuit, the PF value can be improved and the quality of the output voltage can be improved.

The invention discloses a three-level DC conversion circuit with controllable neutral point voltage and a control method thereof. The three-level DC conversion circuit of the present invention comprises a DC power supply, a first capacitor, a second capacitor, a first set of DC chopper circuit and a second set of DC chopper circuit; the first set of DC chopper circuit and the second set of DC chopper circuit are connected in parallel by three points of a positive voltage terminal, a negative voltage terminal and an intermediate voltage terminal, and an output positive terminal of the first setof DC chopper circuit and an output negative terminal of the second set of DC chopper circuit are connected in series with a load; and each of the first set of DC chopper circuit and the second set of DC chopper circuit comprises a plurality of switch tubes and a plurality of diodes. The three-level DC conversion circuit of the invention can constitute a plurality of control modes by controllingconduction of the switch tubes, thereby combining a plurality of timing sequence modes, so that four-quadrant voltage control operation of the load condition can be realized, and the purpose of controlling balance of the neutral point voltage of the three-level circuit can be achieved through mode switch.

The invention relates to a power supply, and particularly relates to an alternating-current (AC) space isolation power supply. The AC space isolation power supply comprises an AC charging power supply, a first rechargeable battery and a second rechargeable battery, wherein the input end of the AC charging power supply is electrically connected with an AC power supply, two groups of switches (K1 and K2) of one group of relays at the positive and negative output ends of the AC charging power supply are connected in series to the positive and negative power supply ends of the first rechargeable battery, and two groups of switches (K3 and K4) of the other group of relays at the positive and negative output ends of the AC charging power supply are connected in series to the positive and negative power supply ends of the second rechargeable battery. The positive and negative power supply ends of the first rechargeable battery are connected in series in a load RL circuit through two groups of switches (K7 and K8) of one relay, and the positive and negative power supply ends of the second rechargeable battery are also connected in series in the load RL circuit through two groups of switches (K5 and K6) of another relay. The two ends of the load RL are provided with voltage detecting circuits, the output ends of which are electrically connected with an I/O port of a single chip microcomputer.

The invention relates to a power supply, especially to an uninterrupted rechargeable battery power supply. The uninterrupted rechargeable battery power supply includes an alternating-current charging power supply, a first rechargeable battery and a second rechargeable battery. The input end of the alternating-current charging power supply is electrically connected with an alternating-current power supply. Two sets of switches (K1, K2) of one set of relay at the positive and negative output ends of the alternating-current charging power supply are connected in series to the positive and negative power supply ends of the first rechargeable battery. Two sets of switches (K3, K4) of another set of relay at the positive and negative output ends of the alternating-current charging power supply are connected in series to the positive and negative power supply ends of the second rechargeable battery. The positive and negative power supply ends of the first rechargeable battery are connected in series in a load RL loop through two sets of switches (K7, K8) of one relay, and the positive and negative power supply ends of the second rechargeable battery are connected in series in the load RL loop through two sets of switches (K5, K6) of another relay. The two ends of the load RL are provided with voltage detecting circuits, the output ends of which are electrically connected with an I/O port of a single chip microcomputer.

The invention discloses an intelligent sine-wave voltage conversion circuit based on a PFC (power factor correction) forward half-bridge. The circuit comprises an input rectifier filter unit, a PFC voltage boosting unit, an isolated two-transistor forward converter and an inversion reverse-phase unit, wherein the isolated two-transistor forward converter comprises a first switch tube, a second switch tube, a first diode, a second diode, a third diode, a fourth diode, a transformer and a filter inductor; the inversion reverse-phase unit comprises a fourth switch tube, a fifth switch tube, a third electrolytic capacitor, a fourth electrolytic capacitor and a first filter inductor, a grid of the fourth switch tube and a grid of the fifth switch tube are used for accessing two ways of PWM (pulse width modulation) pulse signals with opposite phases respectively, a source of the fourth switch tube is further connected to the front end of the first filter inductor, a negative pole of the third electrolytic capacitor is connected to a positive pole of the fourth electrolytic capacitor, and the rear end of the first filter inductor and the negative pole of the third electrolytic capacitor are taken as output ends of the inversion reverse-phase unit. With the adoption of the circuit, PF (power factor) value and output voltage quality can be improved.

The invention discloses an intelligent half-bridge sine-wave voltage switching circuit based on PFC and LLC resonance. The intelligent half-bridge sine-wave voltage switching circuit comprises an input unit, a filter unit, a PFC booster unit, an LLC isolation transformer unit and an inverting reverse-phase unit, wherein the LLC isolation transformer unit comprises a first switching tube, a second switching tube, a transformer, a first diode, a second diode and a first filter inductor, the inverting reverse-phase unit comprises a fourth switching tube, a fifth switching tube, a third electrolytic capacitor, a fourth electrolytic capacitor and a second filter inductor, a source electrode of the fourth switching tube is connected to a drain electrode of the fifth switching tube, a positive electrode of the third electrolytic capacitor is connected to a drain electrode of the fourth switching tube, a negative electrode of the third electrolytic capacitor is further connected to a positive electrode of the fourth electrolytic capacitor, and the source electrode of the fourth switching tube is connected to the front end of the second filter inductor. The intelligent half-bridge sine-wave voltage switching circuit can improve a PF value and output voltage quality.

The invention discloses a PFC, full bridge and half bridge-based intelligent sine wave voltage conversion circuit, which comprises an input unit, a PFC booster unit, a full-bridge isolation conversion unit and an inverse inverter unit, wherein the full-bridge isolation conversion unit comprises a first switch tube, a second switch tube, a sixth switch tube, a seventh switch tube, a transformer, a first diode, a second diode and a first filter inductor; a source of the sixth switch tube is connected to a first end of a primary winding of the transformer; a drain of the second switch tube is connected to a second end of the primary winding of the transformer; a source of the first switch tube is connected to the second end of the primary winding of the transformer; the drain of the seventh switch tube is connected to the first end of the primary winding of the transformer; a center tap of a secondary winding of the transformer is connected to a back-end ground; the rear end of the first filter inductor and an anode of the second diode are taken as output ends of the full-bridge isolation conversion unit; and a second filter inductor is arranged at the output end of the inverse inverter unit. According to the PFC, full bridge and half bridge-based intelligent sine wave voltage conversion circuit, the PF value and the quality of output voltage can be improved.

The invention relates to a high-frequency linear generator analog power supply system and a control method thereof. The system comprises a voltage transformation part, an impedance simulation part, acontrol part and an execution mechanism, the voltage transformation part adopts a cracking transformer to form a DC bus isolated H-bridge cascaded five-level circuit, and the output end of the voltagetransformation part is connected with the impedance simulation part. The control end of the execution mechanism is connected with the voltage transformation part and the impedance simulation part, and the execution mechanism is further connected with the control part to achieve a local control function. According to the method, a segmented asynchronous modulation method is adopted, multi-working-condition testing is carried out on output characteristics, per unit values of the output characteristics are calculated, and curve fitting is carried out; and curves under different frequency division conditions are selected according to the magnitude of the load current and the subsection interval of the initial given frequency, and the output voltage is accurately controlled. According to the present invention, the ripple waves of output voltage waveforms can be effectively reduced, and the output voltage quality and the output frequency precision are improved; and the system and the methodhave the characteristics of short response time, no need of feedback quantity, no delay response and the like.

The invention relates to the field of distribution transformers, in particular to an on-load voltage regulation circuit of an interleaved parallel multi-gear transformer with polarity conversion. Theon-load voltage regulation circuit includes a main winding, a polarity conversion switch, a voltage regulation winding, a transition switching unit, a rated voltage branch and several voltage regulation branches. According to the technical scheme, the polarity conversion switch is arranged between the main winding and the voltage regulation winding, and forward and reverse voltage regulation is realized by adjusting the independent contact switch-on end of the polarity conversion switch. One ends of the voltage regulation branches are respectively connected to the two end taps and middle tapsof the voltage regulation winding, and the other ends are interlaced and connected in parallel into two groups which are connected with the two input ends of the transition switching unit respectively. The input end of the rated voltage branch is connected with the output end of the main winding, and the output end of the rated voltage branch is connected with the output end of the voltage regulation circuit. The beneficial effects are as follows: the on-off frequency of the on-off switch is reduced, and the service life of the corresponding voltage regulation switch is increased; and the transition voltage changes with the voltage regulation gear during voltage regulation, and there is no need for gear-skipping voltage regulation.

The invention relates to the field of distribution transformers, in particular to an on-load voltage regulation circuit of a staggered parallel multi-gear transformer. The on-load voltage regulation circuit comprises a main winding, a polarity reversing switch, a voltage regulation winding, a transition switching unit, a rated voltage branch and a plurality of voltage regulation branches. The polarity reversing switch is arranged between the main winding and the voltage regulation winding, and positive and negative voltage regulation is achieved by regulating the connection end of the independent contact of the polarity reversing switch; one end of each voltage regulation branch is connected to two end taps and the middle tap of the voltage regulation winding; the other ends of the voltageregulation branches are adjacent and staggered and arranged in parallel into two groups which are respectively connected with the two input ends of the transition switching unit, the input end of therated voltage branch is connected with the output end of the main winding, and the output end of the rated voltage branch is connected with the output end of the voltage regulation circuit. The on-off frequency of the on-off switch is reduced, the service life of the corresponding voltage regulation switch is prolonged, the transition voltage changes along with a voltage regulation gear in the voltage regulation process, and gear skipping and voltage regulation are not needed.

The invention discloses a PFC and LLC resonance-based intelligent full-bridge correction wave voltage conversion circuit, which comprises an input rectifier unit, a filter unit, a PFC booster unit and an LLC isolating converter unit, wherein the LLC isolating converter unit comprises a first switch tube, a second switch tube, a first fly-wheel diode, a second fly-wheel diode, a transformer, a resonant capacitor and a discharge resistor; a drain of the first switch tube is connected to an output end of the PFC booster unit; a source of the first switch tube is connected to a first end of the transformer; a second end of the transformer is connected with front-end ground through the resonant capacitor; the drain of the second switch tube is connected to the source of the first switch tube; the source of the second switch tube is connected with the front-end ground through the discharge resistor; and a center tap of a secondary winding of the transformer is taken as the output end of the LLC isolating converter unit. According to the PFC and LLC resonance-based intelligent full-bridge correction wave voltage conversion circuit, the PF value of a voltage conversion device can be improved, the quality of output voltage can be improved and a safe and reliable effect can be achieved.