37results about How to "Reduce the rated voltage" patented technology

The invention discloses a dual-active full-bridge converter-based hybrid energy storage system and a control method therefor. The hybrid energy storage system comprises a supercapacitor, a lithium battery, a dual-active full-bridge converter, a Buck / Boost bidirectional converter and a direct current bus; and two kinds of energy storage equipment form a cascading type hybrid energy storage system. The supercapacitor is connected with the direct current bus through the dual-active full-bridge converter; by adoption of phase-shifting closed-loop control and by collecting the voltage information of the direct current bus, the output power of the hybrid energy storage system can be automatically regulated so as to stabilize the voltage of the direct current bus; the lithium battery is connected with the supercapacitor through the Buck / Boost bidirectional converter; and by adoption of voltage and current dual-closed-loop control, and by collecting the voltage of the supercapacitor, automatic charging and discharging of the lithium battery can be controlled, so that the voltage of the supercapacitor can be maintained within a working voltage range, so as to perform indirect compensation to power fluctuation of a direct current microgrid, reduce action frequency of the lithium battery, and effectively prolong the service life.

The invention discloses a dry type air reactor turn-to-turn insulation performance detection system and method. The system comprises a high-voltage switch cabinet, a variable-frequency test power supply, a test transformer, a reactive power compensation unit, a partial discharge monitoring unit and a tested product unit. 380V three-phase AC current is accessed to the high-voltage switch cabinet. The high-voltage switch cabinet, the variable-frequency test power supply, the test transformer, the reactive power compensation unit, the partial discharge monitoring unit and the tested product unit are connected in turn. The partial discharge monitoring unit comprises a coupling capacitor, measurement impedance and a partial discharge tester. The test product unit comprises a dry type air reactor and an AC voltage measurement unit. The dry type air reactor and the AC voltage measurement unit are connected in parallel. The test transformer excites a resonant loop. The reactive power compensation unit and the tested product unit in the loop are enabled to generate parallel resonance through output frequency of the variable-frequency test power supply. Onsite induced voltage withstanding testing can be performed on the 35kV dry type air reactor so that onsite voltage boosting operation of the reactor can be completed.

The invention discloses a transformerless hybrid active power amplifier and implementation and control methods thereof. The transformerless hybrid active power amplifier comprises a double-turned passive filter and a diode-clamped active filter. The diode-clamped active filter is a tri-level inverter. The double-turned passive filter comprises three passive filter branches connected with phases A, B and C of a power grid respectively. Each passive filter branch comprises an impregnated capacitor (C1), a divider capacitor (C2), a parallel capacitor (C3), a first inductor (L1) and a second inductor (L2). Impregnation points of the three passive filter branches are connected with three terminals on the alternating-current side of the tri-level inverter through three output inductors (L) respectively. The transformerless hybrid active power amplifier features both low cost of a PPF (passive power filter) and excellent filtering and dynamic performance of an APF (active power filter), is easy to implement and is effective in filtering.

The invention discloses a multiport DC-DC autotransformer which is used for achieving interconnection transmission between multiple direct current systems at different voltage levels. The autotransformer comprises 2N-1 transverters, the direct current sides of the 2N-1 transverters are sequentially connected in series, the alternating current sides of the 2N-1 transverters are connected to an alternating current circuit, and the positive electrode of the ith transverter and the negative electrode of the (2N-i)th transverter of the 2N-1 transverters sequentially connected in series are correspondingly connected with the positive electrode and the negative electrode of the ith direct current system respectively, wherein N is the number of the direct current systems, and i is the serial number of one transverter. The invention further discloses a capacity design method of the transverters in the autotransformer and a control method of the autotransformer. Through the multiport DC-DC autotransformer, most of power transmitted between all the direct current systems does not need to be converted in a DC-AC-DC mode and is directly transmitted through electrical interconnection between all the direct current systems, and thus the nominal voltage and the operating loss of all the transverters are greatly reduced, and the operating cost is reduced.

The invention discloses an extra-high voltage neutral-point-electric-reactor site induction voltage withstanding testing system. The system comprises a variable-frequency testing power source, a testing transformer, a compensating capacitor unit and a tested product unit. The variable-frequency testing power source, the testing transformer, the compensating capacitor unit and the tested product unit are sequentially connected. The tested product unit comprises a neutral-point electric reactor and an alternating voltage measuring unit, and the neutral-point electric reactor and the alternating voltage measuring unit are connected in parallel. The invention further discloses an extra-high voltage neutral-point-electric-reactor site induction voltage withstanding testing method. Calculation is carried out according to parameters of site equipment, and it is prevented that a current is excessively large to damage the equipment. By means of the system and method, the bottleneck that a high-voltage large-current induction voltage withstanding test of a traditional electric reactor can not be carried out on site is broken through, it becomes possible that induction voltage withstanding of the 1,000-V extra-high voltage neutral-point electric reactor is carried out on site, the blank of domestic site neutral-point electric-reactor induction voltage withstanding tests is filled, and it is effectively guaranteed that a high-voltage project reliably and safely runs.

The invention discloses a differential driving circuit for powering a light source and a driving system. The differential driving circuit includes a first set of switches and a second set of switches. A first current from a power source flows through the first set of switches to charge a first energy storage element when the first set of switches are turned on. A second current from the first energy storage element flows through the second set of switches to power the light source when the second set of switches are turned on. The differential driving circuit further includes a second energy storage element coupled to the light source in parallel and for providing a differential voltage to the light source. The invention also discloses a driving system for powering a light source, comprising a first switch, a second switch, a third switch and a fourth switch. A first signal controls conducting states of the first switch and the second switch; a second signal controls conducting statesof a third switch and a fourth switch so as to adjust powering to the light source. The nominal voltage of the differential driving circuit is reduced and switch costs are reduced.

The invention discloses a mixedly marshaled battery pack and a mixed marshaling method of the battery pack. According to the mixedly marshaled battery pack, batteries of different capacities are connected in series or in series and in parallel in a mixed marshaling manner, or multiple batteries of same capacity are connected in series and in parallel in a mixed marshaling manner, the rated capacities of corresponding batteries (packs) of unit voltage in the whole marshaled battery pack are not completely same, and power supply leads are arranged at two ends of the batteries (packs) with relatively high capacities and are capable of supplying power outsides, so that a group of battery packs with integrated voltage can be provided for supplying power outsides, and one or multiple groups of auxiliary power supplies with voltages lower than the voltage of the battery packs are further provided for supplying power outsides. The mixedly marshaled battery pack has the beneficial effects that a DC-DC converter matched with the battery pack can be omitted, so that the electric energy loss in a voltage conversion process is avoided, meanwhile, the weight, the size and the cost of a system is reduced, and the reliability of the system is improved; the mixedly marshaled battery pack is convenient to maintain and safe to use.

A method is shown to improve the resonant transition controlled flyback converter presented in Ser. No. 14 / 274,598 (Exhibit A) by adding a clamp circuit that recycles the leakage energy. By utilizing the particular advantages of the resonant transition controlled flyback converter an optimized clamp capacitor can be used to increase the efficiency of the converter further.

The invention discloses an inflation pump. The inflation pump comprises a shell, a driving piece, a gear transmission assembly, a piston rod and an air cylinder; the piston rod is provided with a pushing part, and the piston rod can push a piston sealing ring to move towards the air cylinder through the pushing part; the pushing part comprises a first pushing surface and a second pushing surface,and a height difference is formed at the position where the first pushing surface is connected with the second pushing surface; and when the piston sealing ring acts on the first pushing surface and the second pushing surface, an air leakage channel is formed between the piston sealing ring and the first pushing surface and the second pushing surface. According to the inflation pump, the air leakage channel is formed between the piston sealing ring and the pushing part so as to release the pressure of gas pushed by the piston sealing ring, thus, the piston rod can drive the piston sealing ringto move towards the cylinder, when the back pressure of the inflation pump is started, the acting force of pushing the piston rod again is reduced, the effect of reducing the rated voltage of the driving piece on the inflation pump is achieved, and the application range of the inflation pump is expanded.

Disclosed is a capacitor voltage balance control method of an MMC flying capacitor submodule. The method comprises the steps of: obtaining a voltage reference value of any bridge arm of an MMC; dividing the voltage reference value by a reference voltage of a second capacitor to obtain electrical level value and electric level complementary value needed by the bridge arm at the next moment; measuring voltages of an first capacitor and an second capacitor of each bridge arm submodule to generate a voltage original input sequence; respectively multiplying the odd-numbered bits in the voltage original input sequence by h1, and respectively multiplying the even-numbered bits in the voltage original input sequence by 2h1, so as to obtain a new normalized voltage sequence; successively comparingeach normalized capacitor voltage value in the normalized voltage sequence with other normalized capacitor voltage values in the sequence, summing the comparison results, and arranging the results inorder to obtain a sequence of numbers; measuring the current direction of the bridge arms to obtain a capacitor on-off state sequence; and generating a corresponding IGBT trigger pulse according to the capacitor on-off state sequence. The method improves the stability of the system based on flying capacitor submodules.

The invention discloses a composite insulator device with a built-in piezo-resistance unit. The composite insulator device comprises the piezo-resistance unit, an insulating pillar, enhanced blowout gap units and installation hardware; the piezo-resistance unit comprises a piezo-resistance subunit core, an insulating core rod and an insulating sheath; each enhanced blowout gap unit comprises a blowout cavity, an insulated support member and a gap electrode; and the enhanced blowout gap units are fixedly installed in the two ends of the insulating pillar or arranged uniformly along the axial direction of the insulating pillar. A lightning arrester is integrated with an insulator, the rated voltage of the piezo-resistance unit is reduced by using the high arc extinguishing capability of theenhanced blowout gap unit, and the device is mini, light and cheap; and the device is assembled while leaving the factory, onsite part adjustment and assembly are not needed, it is not required to strip an insulating layer of a lead when the device is connected with the insulating lead, and installation and construction are simple convenient.

An arrangement (23) for tapping power from a DC power line (12) to an AC power line comprises power transfer modules (24A, 24B, 24C) between two DC potentials, each comprising a first branch with a string of converter cells (CA1, CA2, CB1, CB2, CC1, CC2) in parallel with a second branch comprising a capacitor (Csa, Csb, Csc) and being connected to an AC phase (22A, 22B, 22C). There is at least one control unit (26A, 26B, 26C) that controls the arrangement considering one or more of a) distributing appropriate AC and DC voltages in converter output voltages of all series connected modules, b) maintaining / setting cell capacitor voltages in specific range and allowing boost mode operation, c) performing possible balancing of the introduced capacitor and. d) employing an alternate approach of using passive filters to mitigate low order harmonics.

A solid electrolytic capacitor having a capacitor element which includes an anode foil and a cathode foil rolled with a separator interposed therebetween, and a solid electrolyte layer or an electrically conductive polymer layer provided therein. The anode foil is coated with a dielectric oxide film. The dielectric oxide film is an oxide film formed by oxidizing a film of a mono-metal nitride or a composite metal nitride formed on the anode foil. The mono-metal nitride is titanium nitride, zirconium nitride, tantalum nitride or niobium nitride. The composite metal nitride is aluminum titanium nitride, chromium titanium nitride, zirconium titanium nitride or titanium carbonitride.

A voltage source converter including a string of series connected active semiconducting elements. The converter includes in case of an active semiconducting element failure a calculation element configured to calculate an operation dc voltage including a sum of dc ratings of each remaining active semiconducting element in the string, and a regulator configured to regulate the converter to assume the operation dc voltage over the converter.

A solid electrolytic capacitor comprises a capacitor element which includes an anode foil and a cathode foil rolled with a separator interposed therebetween, and a solid electrolyte layer or an electrically conductive polymer layer provided therein. The anode foil is coated with a dielectric oxide film. The dielectric oxide film is an oxide film formed by oxidizing a film of a mono-metal nitride or a composite metal nitride formed on the anode foil. The mono-metal nitride is titanium nitride, zirconium nitride, tantalum nitride or niobium nitride. The composite metal nitride is aluminum titanium nitride, chromium titanium nitride, zirconium titanium nitride or titanium carbonitride.

The invention relates to a bidirectional DC-DC converter with intermediate conversion into AC power, including: a DC-AC conversion circuit using a plurality of MOSFETs; an AC-DC conversion circuit using a plurality of power diodes; a transformer; a pair of switches, one of which being inserted in series between a DC terminal of the DC-AC conversion circuit and the AC-DC conversion circuit and the other of which being inserted in series between another DC terminal of the DC-AC conversion circuit and the AC-DC conversion circuit; and a controller being adapted for turning on the pair of switches such that the plurality of power diodes of the AC-DC conversion circuit are reverse-biased where the AC power is transferred in the forward direction and turning off the pair of switches where the AC power is transferred in the backward direction.

An energy recovery device consists of plate capacity formed by equivalence between scan electrode and maintenance electrode, source capacity for carrying out recovery charging on voltage charging to plate capacity, maintenance voltage source for supplying maintenance voltage to plate capacity and initial charging voltage source for supplying initial charging voltage to source capacity. It features that initial charging voltage value is applied to carry out charging on source capacity in order to decrease rated voltage of switching component.

A differential driving circuit (200) for powering a light source (210) is disclosed. The differential driving circuit includes a first set of switches and a second set of switches. A first current from a power source (201) flows through the first set of switches (221,223) to charge a first energy storage element (225) when the first set of switches is turned on. A second current from the first energy storage element (225) flows through the second set of switches (222,224) to power the light source when the second set of switches are turned on. The differential driving circuit further includes a second energy storage element (250,260) coupled to the light source in parallel and for providing a differential voltage to the light source.

The invention discloses a dual-active full-bridge converter-based hybrid energy storage system and a control method therefor. The hybrid energy storage system comprises a supercapacitor, a lithium battery, a dual-active full-bridge converter, a Buck / Boost bidirectional converter and a direct current bus; and two kinds of energy storage equipment form a cascading type hybrid energy storage system. The supercapacitor is connected with the direct current bus through the dual-active full-bridge converter; by adoption of phase-shifting closed-loop control and by collecting the voltage information of the direct current bus, the output power of the hybrid energy storage system can be automatically regulated so as to stabilize the voltage of the direct current bus; the lithium battery is connected with the supercapacitor through the Buck / Boost bidirectional converter; and by adoption of voltage and current dual-closed-loop control, and by collecting the voltage of the supercapacitor, automatic charging and discharging of the lithium battery can be controlled, so that the voltage of the supercapacitor can be maintained within a working voltage range, so as to perform indirect compensation to power fluctuation of a direct current microgrid, reduce action frequency of the lithium battery, and effectively prolong the service life.

The invention discloses a transformerless hybrid active power amplifier and implementation and control methods thereof. The transformerless hybrid active power amplifier comprises a double-turned passive filter and a diode-clamped active filter. The diode-clamped active filter is a tri-level inverter. The double-turned passive filter comprises three passive filter branches connected with phases A, B and C of a power grid respectively. Each passive filter branch comprises an impregnated capacitor (C1), a divider capacitor (C2), a parallel capacitor (C3), a first inductor (L1) and a second inductor (L2). Impregnation points of the three passive filter branches are connected with three terminals on the alternating-current side of the tri-level inverter through three output inductors (L) respectively. The transformerless hybrid active power amplifier features both low cost of a PPF (passive power filter) and excellent filtering and dynamic performance of an APF (active power filter), is easy to implement and is effective in filtering.

A voltage source converter including a string of series connected active semiconducting elements. The converter includes in case of an active semiconducting element failure a calculation element configured to calculate an operation dc voltage including a sum of dc ratings of each remaining active semiconducting element in the string, and a regulator configured to regulate the converter to assume the operation dc voltage over the converter.

A lightning arrester degradation protection device, which relates to the technical field of lightning arresters. The upper end of the lightning arrester degradation protection device is connected to the lightning arrester, and the lower end is connected to the grounding copper bar. It includes a compensation impedance element, an increasing resistance switch and a control unit. The compensation impedance element One end is connected to the low-voltage end of the arrester, the compensation impedance element is connected in parallel with the resistance increasing switch and then grounded, the circuit after the compensation impedance element and the resistance increasing switch is connected in parallel is connected in series with the control unit through the magnetic flux sensor, and the described The control unit controls the connection of the increasing resistance switch. During normal operation, the increasing resistance switch is closed and the compensation impedance element is short-circuited, which is equivalent to directly grounding the ground terminal of the arrester. When the control unit detects that the leakage current of the arrester exceeds the limit value, it sends an opening command to drive the The resistance switch is disconnected, and the compensation impedance element is connected in series to the arrester circuit to achieve the purpose of reducing the leakage current.

Disclosed is a capacitor voltage balance control method of an MMC flying capacitor submodule. The method comprises the steps of: obtaining a voltage reference value of any bridge arm of an MMC; dividing the voltage reference value by a reference voltage of a second capacitor to obtain electrical level value and electric level complementary value needed by the bridge arm at the next moment; measuring voltages of an first capacitor and an second capacitor of each bridge arm submodule to generate a voltage original input sequence; respectively multiplying the odd-numbered bits in the voltage original input sequence by h1, and respectively multiplying the even-numbered bits in the voltage original input sequence by 2h1, so as to obtain a new normalized voltage sequence; successively comparingeach normalized capacitor voltage value in the normalized voltage sequence with other normalized capacitor voltage values in the sequence, summing the comparison results, and arranging the results inorder to obtain a sequence of numbers; measuring the current direction of the bridge arms to obtain a capacitor on-off state sequence; and generating a corresponding IGBT trigger pulse according to the capacitor on-off state sequence. The method improves the stability of the system based on flying capacitor submodules.

The invention relates to a DC-DC converter with an output-sided storage capacitor assembly, which is formed from of a parallel connection of an electrolytic capacitor (1), a ceramic capacitor (2) anda circuit arrangement with a series connection of a hybrid electrolyte capacitor (3) and a suppressor diode (4) and a resistor (5) which is connected in parallel to the hybrid electrolyte capacitor (3).

The invention provides a power decoupling circuit for a photovoltaic grid-connected inverter, and relates to circuit devices of alternating-current main lines or alternating-current power distribution networks. The power decoupling circuit is composed of a filter capacitor, an inductor, a decoupling capacitor A, a decoupling capacitor B, a switch tube A and a switch tube B. The decoupling capacitor A is in parallel connection with the filter capacitor after being in series connection with the decoupling capacitor B, a collector of the switch tube A in series connection with the switch tube B is connected to a positive pole node of the part, in parallel connection with the filter capacitor, of the decoupling capacitor A in series connection with the decoupling capacitor B,, an emitter of the switch tube B in series connection with the switch tube A is connected to a negative pole node of the part, in parallel connection with the filter capacitor, of the decoupling capacitor A in series connection with the decoupling capacitor B, and an intermediate node enabling the decoupling capacitor A to be in series connection with the decoupling capacitor B is connected to the connecting point of an emitter of the switch tube A and a collector of the switch tube B through the inductor. The defects that an existing photovoltaic grid-connected inverter needs large-capacity and large-size decoupling capacitors and is complex in structure and high in cost are overcome.

Disclosed is a three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier. The three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier includes a rectifier bridge and a three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier transformer. The rectifier transformer is provided with a primary winding, a secondary winding and an iron core. Primary winding wiring is triangular, star-shaped, hexagonal or extended hexagonal. In the secondary winding, the phases each have a set of long side output winding which has the same numberof turns of each phase and are symmetrical and three-phase connected or not-connected and two sets of short side windings which have the same number of turns of each phase and are symmetrical, and the head end of each phase of the long side output winding is connected to the head ends of the other two phases of short side output windings or the tail end of each phase of the long side output winding is connected to the tail ends of the other two phases of the output windings to form three inequilateral Y-shaped windings. The primary winding and the secondary winding are arranged concentricallyor up-down on each phase of an iron core column and are wound after being insulated by metal foil or a conductor. The iron core is a three-phase iron core shaped like a Chinese character 'ri' or delta-shaped or three single-phase iron cores which are square-shaped, a shell type shaped like a Chinese character 'ri' or double-ring shaped shell type. The three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier can be powered by a four-wire direct current system and is low in harmonic content and cost.

Disclosed is a three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier. The three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier includes a rectifier bridge and a three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier transformer. The rectifier transformer is provided with a primary winding, a secondary winding and an iron core. Primary winding wiring is triangular, star-shaped, hexagonal or extended hexagonal. In the secondary winding, the phases each have a set of long side output winding which has the same numberof turns of each phase and are symmetrical and three-phase connected or not-connected and two sets of short side windings which have the same number of turns of each phase and are symmetrical, and the head end of each phase of the long side output winding is connected to the head ends of the other two phases of short side output windings or the tail end of each phase of the long side output winding is connected to the tail ends of the other two phases of the output windings to form three inequilateral Y-shaped windings. The primary winding and the secondary winding are arranged concentricallyor up-down on each phase of an iron core column and are wound after being insulated by metal foil or a conductor. The iron core is a three-phase iron core shaped like a Chinese character 'ri' or delta-shaped or three single-phase iron cores which are square-shaped, a shell type shaped like a Chinese character 'ri' or double-ring shaped shell type. The three-phase 18-pulse asymmetric Y-shaped output winding phase-shifting rectifier can be powered by a four-wire direct current system and is low in harmonic content and cost.