250results about How to "Reduce overvoltage" patented technology

The present invention includes an apparatus and method of making and using a composition that includes the replacement of electrochemically inactive additives with a conductive and electrochemically active polymer that is attached so as to make an electrical contract to the redox couples of the electrochemically active oxide particles into/from which Lithium is reversibly inserted/extracted in a battery discharge/charge cycle.

The invention discloses a composite material used as a lithium air battery positive electrode and a preparation method thereof. The composite material comprises nanometer manganese dioxide (MnO2) and porous carbon which are compounded on the molecular level and are bonded by a hydrogen bond; and the molar ratio of the porous carbon to the nanometer MnO2 is 10:1 to 20:1. The porous carbon is uniform in aperture and large in specific surface area; the nanometer MnO2 is low in cost, non-toxic, high in average voltage and energy compatibility and extremely high in catalytic activity; and moreover, overpotential can be effectively reduced. The nanometer MnO2 used as a catalyst is deposited on the surface of the porous carbon material by a hydrothermal method or an oxidation-reduction method, so that precious metal salt is avoided, the cost is low, the practicability is high, the composite material is clean and environment-friendly, and the requirement on environment protection is met; and in addition, the method is simple and feasible, and complicated and harsh reaction conditions and side reaction are avoided.

The invention discloses a mixed type three-pole direct current power transmission system and a control method thereof. The system comprises a rectifying converter station and an inverting converter station, wherein the rectifying converter station and the inverting converter station respectively comprise an alternating current bus and a three-pole converting system, each alternating current bus is connected with a corresponding alternating current power grid, each three-pole converting system is hung on each alternating current bus through a converting transformer, and a converting unit H3 of each three-pole converting system adopts an MMC (modular multilevel converter). The system and the method have the advantages that the decoupling control capability of the active and inactive parts is realized, the power can be transmitted to an inactive network, the number of inactive compensation equipment is greatly reduced, the balance of the direct current among the three poles is maintained by introducing the MCC (modified current control), the current of a grounding pole is inhibited, the service life of the grounding pole is effectively prolonged, the on-site balance of the inactive power is realized by introducing the AVC (alternating voltage control), and the voltage of the connected AC (alternating current) system is maintained to solve the overvoltage or undervoltage problem.

A method for coordinating and controlling a multi-terminal flexible direct current transmission system, the method comprising the following steps: (1) a sagging slope control regulated by direct current is added to a constant direct current voltage station in a multi-terminal flexible direct current transmission system; (2) the sagging slope control regulating direct current voltage is added to a constant active power station; (3) when interstation communication does not exist, two constant current voltage stations in a multi-terminal system are set as constant direct current voltage control stations, and the constant direct current voltage control stations serve as balancing nodes in a direct current network. When the system operation condition is out of the range adjusted by the direct current voltage sagging slope control, the method optimally adjusts the system direct current voltage and the power of each station, such that the direct current network can maintain the optimal voltage level after experiencing a major failure.

The large aluminum electrolyzing pre-roasting tank includes anode carbon block combination, anode bus, breaking and feeding unit, anode elevating mechanism, crossbeam and portal upright, tank sealing air exhaust system, tank casing, cathode structure and bottom heat insulating structure. It features the double anode structure comprising two anode carbon blocks assembled through aluminum rod and steel pawl; the elevator installed below the top surface of the crossbeam; the tank sealing air exhaust system set inside the crossbeam; and the cathode with surround casing, carbon block with bottom composite heat insulating layer, side silicon nitride to combine silicon carbide blocks and surrounding cast material. The present invention has improved structure resulting in raised fume collecting efficiency, reasonable gas flow distribution and smooth aluminum electrolyzing process.

The invention discloses a packaging structure and a packaging method for a silicon carbide power device. The packaging structure comprises a direct bond copper (DBC) ceramic substrate, a silicon carbide power device, a PCB, leads and a shell and forms a half-bridge circuit structure formed by the silicon carbide power device. According to the packaging structure and the packaging method provided by the invention, the area of a power circuit can be effectively reduced, conductors with opposite current flowing directions are formed during a commutation process by a switch transistor, mutual inductance offset is used for reducing parasitic inductance of a commutation circuit, and overvoltage and oscillation during the switching process can be effectively reduced; driving signal leads adopt a Kelvin connection mode and are vertical to power leads, a role of effectively reducing coupling between a driving circuit and a power circuit is played, and driving stability is enhanced; the DBC substrate and the PCB are welded thoroughly, and packaging reliability is enhanced; and power terminals and signal terminals are directly included in the PCB, thereby reducing contact resistance and parasitic inductance brought by extra terminals and achieving effects of reducing the cost.

An apparatus and method of controlling an electrical generating apparatus is provided. The apparatus includes an electrical generator configured to be connected to an electrical grid and a converter comprising an inverter connected to a rotor of the electrical generator. The apparatus also includes a shunt protection circuit connected to the inverter and the rotor of the electrical generator and a control unit configured to activate and deactivate the inverter and the shunt protection circuit. The control unit is configured to, in response to determining that an abnormal condition is occurring in the electrical generator or an electrical grid to which the electrical generator is connected, deactivate the inverter and activate the shunt protection circuit. Also, after it is determined that the abnormal condition has passed, the control unit is configured to activate the inverter before deactivating the shunt protection circuit.

The present invention magnesium alloy material surface phosphatizing solution and its treating process. The surface phosphatizing solution consists of 85 % concentration phosphoric acid solution in 10-20 ml/l, zinc oxide in 1-5 g/l, sodium fluoride in 1-3 g/l, sodium nitrate in 0.1-0.4 g/l, hydrogen peroxide in 0.5-1 g/l and water for the rest. Hydrogen peroxide is adopted as the promoter to speed film formation and raise the corrosion resistance of the produced conversion film and adhesion of the lacquer film, and as the environment friendly oxidant. The surface phosphatizing solution has simple composition, easy control, stable technological process and low cost, and is suitable for industrial production.

A multilevel converter converting between AC and DC includes a phase leg having a first and a second phase arm, the first phase arm being connected between a first pole having a first potential and a first AC terminal and the second phase arm being connected between the first AC terminal and a second potential, where the phase arms include half-bridge and full-bridge cells, where each cell includes at least one energy storage element for providing the voltage contribution and cell switching units with cell switches and anti-parallel diodes for controlling the voltage contribution, where the full-bridge cells include a bypass switch controllable to bypass the corresponding energy storage element, and when a phase-to-ground fault occurs the cell switches are blocked and the bypass switches activated with a delay in relation to the blocking.

The invention provides an electrode for electrolysis, an electrolytic cell, and a method for manufacturing the electrode for electrolysis. The electrode for electrolysis is capable of reducing overvoltage in the early period of electrolysis. The electrode for electrolysis comprises a conductive base material, a first layer formed on the surface of the conductive base material and a second layer formed on the surface of the first layer, wherein the first layer contains ruthenium oxide, iridium oxide and titanic oxide and the second layer contains the ruthenium element and does not contain the iridium element.

A circuit for regulating a DC voltage is provided. The circuit includes: a controllable switch system, a resistor, a first control circuit and a second control circuit. The controllable switch system includes a first terminal, a second terminal, a first control terminal, and a second control terminal. The controllable switch system is configured to establish an electrical connection between the first terminal and the second terminal, if a first control signal applied to the first control terminal satisfies a first criterion or if a second control signal applied to the second control terminal satisfies a second criterion; A A method for regulating a DC voltage and an AC-to-AC-converter are described.

The invention discloses a short-circuit protection circuit for an APF high-power IGBT. The short-circuit protection circuit comprises the working control circuit of the IGBT and the short-circuit protection circuit of the IGBT, the working control circuit of the IGBT is used for controlling the IGBT to work or not, and the short-circuit protection circuit of the IGBT is used for monitoring the short circuit currents of the IGBT and preventing the short circuit of the IGBT from causing overvoltages to damage the IGBT through a slowly lowered grid voltage circuit. The short-circuit protection circuit of the IGBT comprises the working control circuit of the short-circuit control circuit, the detecting circuit of the short-circuit protection circuit, the slowly lowered grid voltage circuit and a latch protecting resetting circuit, wherein the working control circuit is used for controlling the short-circuit protection circuit to work or not, the detecting circuit is used for detecting the voltage of the IGBT, the slowly lowered grid voltage circuit is used for slowly lowering grid voltages, and the latch protecting resetting circuit is used for protecting and locking a PWM, and completely turning off the IGBT. The short-circuit protection circuit for the APF high-power IGBT has the advantages of improving the reliability of the working circuit, and reducing the overvoltages in a turning off process by adopting the soft turn-off mode of slowly lowering IGBT grid voltages when a short circuit occurs.

The invention discloses a wind power soft straight system with an automatic fault ride-through capability and a control method thereof. The system comprises a wind power plant, a wind field side converter station, a power grid side converter station and a dissipative module. The wind field side converter station and the power grid side converter station include a direct current basic controller and a fault ride-through controller and are used for realizing automatic current limiting control of alternating current and direct current faults. The dissipation module is used to protect an overvoltage of each converter station submodule from being lower than a rated value during a fault period. The method comprises the following steps of detecting voltage signals of alternating current and direct current ends and automatically identifying the alternating current and direct current faults; realizing the automatic current limiting control of the alternating current and direct current faults bycomparing the direct current basic controller and the fault ride-through controller; connecting a dissipative resistor in parallel to alternating current sides of the wind field side converter station and the power grid side converter station, and realizing dissipation through a switching criterion. Under the coordination effect of the automatic current limiting control and the dissipative resistor, a fault current, a voltage and MMC energy during an alternating current and direct current fault period is in a safe range so as to ensure the transient safe operation of the alternating current and direct current faults of the whole system.

The invention relates to a filling system for filling valve bags, and to a method for operating a filling system, which comprises at least one rotating packing machine having a drive for rotating the packing machine, and a plurality of filling nozzles, which are distributed across the periphery of the rotating packing machine. The filling nozzles are provided for receiving the valve bags and can be fixed to the filling nozzles at an opening, and they may be filled with a pourable material through the filling nozzles. The valve bags are placed onto the filling nozzles at a defined insertion position and are automatically released at a defined release position. The invention provides a controller in order to control the filling process. A pressure sensor (10) is associated with at least one filling nozzle in order to determine a degree of the filling pressure of the valve bag disposed at the filling nozzle. The controller determines a representative characteristic pressure value for the filling pressure present at a predetermined position (51) in front of the release position by means of a pressure sensor, and adjusts a rotational speed of the packing machine to the speed of the drive by way of a control unit.

Provided are a solid battery which can reduce overvoltage and a regeneration method thereof. The solid battery comprises: an anode capable of absorbing and releasing an alkali metal ion or alkaline earth metal ion; a solid electrolyte layer containing a solid electrolyte having ion conductivity and disposed in a manner to contact the anode; a cathode capable of releasing and absorbing the alkali metal ion or alkaline earth metal ion which moves between the anode and cathode; a heating device to heat the anode to a temperature at which it softens; and a fastening device capable of applying force to closely contact the solid electrolyte layer with the anode. The regeneration method comprises the steps of heating the anode to a temperature at which it softens, and compressing the softened anode, in a direction intersecting a face of the anode which contacts with the solid electrolyte layer.

This invention discloses an electrical technology Phased - Petersen coil fault detection method. This invention will first Phased - Petersen coil system to the power grid system and then use Petersen coil controller neutral point of the voltage and current system, if detected elevated to neutral voltage settings, the control of its calculated system grounding resistance, the preliminary determination grounding system running state controller set for final adoption grounding type criterion determine the grounding system operating state control Phased - Petersen coil winding of the second on - SCR Kok change Petersen coil operations, if finally found a permanent grounding system, so that Petersen coil running away from the resonance point, and issued warning notice. The invention introduces discriminant grounding resistance auxiliary methods, giving full consideration to the system over-voltage neutral point of the various situations so that the types of fault detection more accurate.

The invention relates to a novel power conversion unit allowing a laminated coating row and a composite busbar to be used in a hybrid mode. The problems that for a traditional cable connection mode, external output appearance is messy, capacity expansion is not easy, and layout and connection cannot be achieved when current becomes larger are solved. The novel power conversion unit comprises an air-cooled radiator, a frame, the composite busbar, a mounting plate, three IGBTs, eight support capacitors, three absorption capacitors, three drive circuit boards and two discharge resistors. On the basis of the air-cooled radiator, the multi-busbar laminated modular design is adopted. As the modular design is adopted, space is saved, maintenance and replacement are facilitated, and the maintenance cost is lowered; by the adoption of the multi-type composite busbar combination use technology, the reliability of a main circuit is improved, and the difficulty that a cable detours in a narrow space is completely avoided; besides, since the structure is compact, expansion of higher power is facilitated, and operation loss and the maintenance cost caused by faults can be reduced.