62 results about "Transient mode" patented technology

The invention relates to a micro-grid experiment system which comprises a wind power generation unit, a photovoltaic grid-connected power generation unit, an energy storage unit, a third-class load, a load control device, a dummy load, a PV (photovoltaic) simulator, a frequency converter, an AC (Alternate Current) grid-connected cabinet, a micro-grid switching-in cabinet, a central controller, interconnection switches, a cable and a bus. By the state of each interconnection switch, different operation modes and configuration modes of a plurality of micro-grids can be realized. The operation modes comprise a single micro-grid grid-connected mode, a multiple micro-grid grid-connected mode, a single micro-grid islanding mode, a multiple micro-grid islanding mode and a transient mode. The system effectively utilizes renewable energy sources. The influence of power supply on the environment is reduced. A gel battery and a super capacitor are used as energy storage elements, so that not only is the micro-grid experiment system economic, but also the pollution to the environment is reduced and the micro-grid experiment system has relatively long service life and high charging speed. The system can be used for developing research on various micro sources such as wind, light, storage and the like, a combined system of the micro sources, various micro-grid operation modes and micro-grid and distribution network interactive influence and has excellent expansibility on both hardware and software.

A latch-up-free ESD protection circuit using SCR is disclosed, in which an SCR is connected between the input pad and the negative power supply; a turn-on switch and a turn-off switch are connected between the positive power supply V_DD (or the input pad) and the SCR; and a transistor gating circuit is connected to the turn-on switch and the turn-off switch to direct the operation of the SCR. When overvoltage stress develops over the input pad in the fast-transient mode, the turn-on switch enables the NPN transistor to switch on the SCR to form a discharging path for electrostatic discharge; and when overvoltage stress is released, the turn-off switch enables the PNP transistor to switch off the SCR, thus making it immune to any latch-up after the overvoltage stress is released, and having the advantages of fast triggering, low trigger voltage, no latch-up, and full ESD protection in the active and passive modes.

In a power-generator control apparatus, a control circuit intermittently controls the supply of a field current from a battery to a field winding of a power generator in normal mode so as to adjust power induced in an output winding of the power generator. The control circuit interrupts the supply of the field current from the battery to the field winding in transient mode when a transient voltage occurs. An energy absorbing circuit absorbs magnetic energy stored in the field winding independently of magnetic-energy consumption by a resistance of the field winding itself.

A transient voltage protection circuit that protects a load from transient voltages is disclosed. The circuit includes a series combination of a thyristor surge protection device (TSPD), a resistor and a transorb coupled for coupling in parallel with the load, and a fuse coupled between an AC input and the series combination. The TSPD and the transorb are configured to enter a transient mode upon application of a transient voltage to the circuit to shunt current from the load and provide an AC output voltage to the load less than the transient voltage without opening the fuse.

The invention discloses a one-side welding with back formation welding method for a large double-layer cylinder of a nuclear power station. Gas metal arc welding is used, proper bevel angles and welding process parameters are adopted, a backing weld is subjected to semi-automatic welding, filling and capping welds are subjected to automatic welding, and efficient one-side welding with back formation is realized. According to the welding method, argon-rich mixed gas is used as protective gas, backing welding adopts small current parameters, the transient mode of controlling molten drops includes short-circuit transition and spray transition, a welding gun swings and temporarily stays at a truncated edge in backing welding, and through welding is ensured. The molten drop transient mode of the filling and capping welds includes pulsed spray transition, welding efficiency can be effectively improved, welding heat input is reduced, and welding deformation is decreased. The welding method is suitable for field welding, and stable welding quality can be ensured when local assembling alignment tolerance or clearance of a weldment is large and cannot be adjusted.

According to the invention, noise of an internal combustion engine is reduced by dynamically correcting the moment of injection when the engine is in the transient mode.

The invention discloses a control method and system for a pulse MIG (Metal-Inert Gas) welding electric arc. The method and the system disclosed by the invention has the advantages that the pilot-arc width or the pulse frequency of the pulse MIG electric arc is commonly controlled in a loop-opened feed-forward control mode of a welding-wire feeding speed signal and a loop-closed negative-feedback control mode of an electric arc length signal so as to maintain dynamic balance of the feeding speed and the fusion speed of welding wires and maintain constant electric arc length of the system and a constant jet transient mode of molten drops when welding current adjustment (by adjusting the wire-feeding speed), wire-feeding speed disturbance or arc length disturbance occurs. In addition, the invention also discloses a new process which adopts the method and the system and is used for controlling the fusion depth and the forming of welding seams by adopting a pulsating feeding mode for welding.

A method and control system to accomplish knock control on a multi-cylinder spark-ignition internal combustion engine equipped variable cam phasing system, comprising monitoring cam position, crankshaft position, and, engine knock signal, determining cam position relative to crankshaft position, and implementing either a global cylinder knock control strategy or an individual cylinder knock control strategy, based upon whether the determined cam position relative to crankshaft position is near a default position, the determined cam position indicates the variable cam phasing system is operating in a transient mode, or, the determined cam position relative to crankshaft position is substantially different from the default position.

A variable capacity compressor that is operable in a normal mode and either an upward or downward rapid transient mode includes a compressor that compresses a fluid and a motor that drives the compressor. A controller powers the motor from a main power source when operating in the normal mode and powers the motor from a supplemental power source when operating in the upward rapid transient mode.

A ballast resonant inverter with a self-oscillating driver IC powers and dims a gas discharge lamp. A feedback circuit automatically adjusts IC oscillator frequency for safe and stable inverter operation above the resonant frequency following changes in the resonant load. The feedback signal is derived from resonant inverter output voltage, by attenuating, programmed phase shifting and injecting the resulting signal in a timing circuit of the IC. The feedback circuit includes an active inverter circuit or passive RC phase boosting networks coupled in series. Phase control of the feedback signal by variable RC networks is used in transient modes of ballast-lamp operations.

The invention provides a marine electric power system modularization simulation method. A marine electric power system modularization simulation platform comprises a human-computer interface module, a power network path intelligentization analysis module, a marine electric power system analysis module, an information storage module and a transient state simulation curve output module. Firstly, the human-computer interface module is used for building a marine electric power system. The power network path intelligentization analysis module is used for obtaining numerical symbols of devices in a whole power network from the human-computer interface module from the information storage module. The marine electric power system analysis module is used for obtaining path connecting relations between generating lines of the power network path intelligentization analysis module from the information storage module, and obtaining generating line node data information of the human-computer interface module from the information storage module. The transient state simulation curve output module is used for obtaining data calculated in a transient mode of the marine electric power system analysis module from the information storage module to finish the drawing of a curve. A marine electric power system simulation platform which is easy to operate and high-efficient in simulation is provided.

The invention discloses a steering control method for a hinged steering distributed electrically-driven loader, and the method comprises a steady state mode and a transient state mode; the steady state mode comprises the steps: calculating steady state target wheel speeds of four wheels according to the current vehicle speed and a vehicle frame rotation angle, and calculating to obtain output torques of all driving wheels through closed-loop control of the steady state target wheel speeds and feedback wheel speeds; the transient mode comprises the steps: calculating the expected steering angular velocity increment of a front frame and a rear frame according to the change rate of the opening degree of a steering handle, and obtaining the output torque of each driving wheel through closed-loop control over the transient target wheel speed and the feedback wheel speed. The invention further relates to a hinged steering distributed electric drive loader steering control system. The hinged steering distributed electric drive loader steering control system comprises an electric drive wheel set, a hydraulic hinged steering system, a front frame, a steering angle sensor, a hinged pin shaft, a rear frame, a speed pedal, a steering handle and a whole vehicle controller. The problems that in the steering process in the prior art, maneuverability and stability are poor, steering energy consumption is high, and tire abrasion is serious are solved.

The described sensor allows determination of the concentration of a gas in a two-component mixture at variable pressure by measuring the diffusivity and the thermal conductivity. The sensor is provided to alternately heat the membrane of a thermally conductive cell and allow it to cool such that the temperature T_M of the membrane passes from a first stable value to a second stable value and vice versa via a transient mode. The cell produces a signal representative of the temperature T_M of the membrane and the sensor extracts from the signal a first and a second parameter that respectively relate to said first stable value and said transient mode of the signal. A value of the concentration of said gas and of the pressure of said two-mixture is calculated from these two parameters.

The invention aims at providing a transient EGR control method based on a neural network. The cyclic oil supplying amount is calculated according to the current work condition of a diesel engine, then a cyclic oil supplying amount signal is transmitted to a target oxygen content calculating unit which works out a target oxygen content value A under the work condition, and A is transmitted to a PI controller unit; and the BP neural network predicts a predicted oxygen content in a scavenge air collection pipe of the diesel engine, the oxygen content value is fed back to the PI controller unit, the target oxygen content value A is compared with the fed-back predicted oxygen content in the scavenge air collection pipe to make a difference, an EGR valve opening degree signal is acquired through the PI controller unit and is transmitted to an executing mechanism of an EGR valve and the BP neutral network, and finally, the EGR valve opening degree is made stable. By means of the transient EGR control method based on the neural network, a series of problems caused when traditional PI feedback is controlled at a transient mode switching and under a TierIII mode, an oxygen content sensor seriously lags behind at the time of transient load increasing and decreasing can be well solved.

The invention relates to an inverter IGBT tiny fault feature extraction method based on multi-modal data. The method comprises the following steps: 1), building an equivalent second-order system of a transient mode of a two-level traction inverter, and carrying out the parameter identification of an expression of the equivalent second-order system; 2) carrying out modal division on the output voltage data of the inverter through an Elman neural network; 3) extracting corresponding tiny fault characteristic parameters in each transient mode, wherein the tiny fault characteristic parameters comprise a voltage overshoot sigma, peak time tp and a voltage slope absolute value delta; 4) extracting a voltage steady-state value Vstab in each steady-state mode; and 5) carrying out fault detection according to the extracted characteristic parameters of the IGBT tiny fault. Compared with the prior art, the method has the advantages of easy realization, cost saving, noise interference reduction, modal classification accuracy improvement, accurate extraction, fault detection and the like.

The invention relates to method for operating a large diesel engine, a purpose and a large diesel engine. The large diesel engine can be operated under at least one fuel gas; under the fuel gas state, the gas is used as a fuel to be guided into an air cylinder (21) and is guided away through an exhaust valve(24), wherein during operation under the fuel mode (10), an acute change state (13) of a load is detected, the large diesel engine is operated under a transient mode; the transient mode comprises steps of determining a close angle for closing the exhaust valve under the fuel gas state, determining a correction value (14) for the closed angle, determining a transient closed angle (14) through correlation between the closed angle and the correction value; and the exhaust valve (15) is closed at the transient closed angle.