142results about How to "Current smoothing" patented technology

A power converter for converting energy from a green power unit as e.g. a solar cell into energy fed into the commercial grid is described. The object is to provide a versatile modularized power converter with eased access to control of the power switches. Another object is to improve the electrical efficiency. This is achieved by using an independent controller on a DC/DC module and an independent controller on a DC/AC module, whereby the the two independent controllers communicate with each other and the outside world by means of a communication bus. Further, the DC/DC module of the power converter comprises a transformer which transfers energy from the DC/DC module to the DC/AC module. This design enables independent control of the modules and eases controllability of the power switches in order to suppress retroaction from pulsations generated on the mains when supplying energy to a single phase grid. Hereby the electrical efficiency of the power converter is increased. Also, an active snubber circuit is described which further increase the efficiency.

A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited in advance of zero-crossings of back emf in the winding by an advance angle, and the winding is freewheeled over a freewheel angle. The method then includes varying the advance angle and the freewheel angle in response to changes in the speed of the electric machine. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited in advance of zero-crossings of back emf in the winding by an advance angle, and the winding is freewheeled over a freewheel angle. The method then includes varying the advance angle and the freewheel angle in response to changes in the voltage used to excite the winding. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

A method of controlling a permanent-magnet motor that includes sequentially exciting and freewheeling a winding of the motor. The method includes varying the angle over which the winding is freewheeled in response to changes in speed of the motor. Additionally, a control system for a permanent-magnet motor, and a product incorporating the control system and motor.

An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine under load at speeds in excess of 60 krpm. Additionally, a product that includes the electric system.

A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited by an excitation voltage and is freewheeled over a freewheel angle. The method then includes varying the freewheel angle in response to changes in the excitation voltage. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine. The control system sequentially excites and freewheels a winding of the electric machine so as maintain substantially constant power over an operating speed range spanning at least 10 krpm and/or an excitation voltage range extending between a minimum voltage and a maximum voltage, the minimum voltage being less than 80% of the maximum voltage. Additionally, a product comprising the electric system.

In order to form a metal thin film, a silicide film, or the like between an upper-layer unit cell and a lower-layer unit cell in stacked-layer photoelectric conversion devices, a step of forming the thin film is additionally needed. Therefore, a problem such as decline in productivity of the photoelectric conversion devices occurs. A first unit cell including a single crystal semiconductor layer with a thickness of 10 μm or less as a photoelectric conversion layer and a second unit cell including a non-single-crystal semiconductor layer as a photoelectric conversion layer, which is provided over the first unit cell, are at least included, and conductive clusters are dispersed between the unit cells. The conductive clusters are located between the lower-layer unit cell and the upper-layer unit cell to form an ohmic contact; thus, current flows between the both unit cells.

Input/output devices with robustness of ESD protection are provided. An input/output device comprises an input/output pad, a first NMOS transistor, a second NMOS transistor and an ESD detector. The first NMOS transistor comprises a first drain, a first source and a first gate, wherein the first source and the first gate are coupled to a first ground power rail, and the first drain to the input/output pad. The second NMOS transistor comprises a second drain, a second source and a second gate, wherein the second source is coupled to the first ground power rail, the second drain to the input/output pad, and the second gate to a first pre-driver. When an ESD event is detected, the ESD detector makes the first pre-driver couple the second gate to the first ground power rail, thereby the first and second transistors evenly discharge ESD current.

Circuits and methods for current limited DC-to-DC converters having multiple power sources have been disclosed. One of multiple power sources is activated by a multiplexer. A current sensing unit, deployed close to the multiplexer, detects if an input current to the DC-to-DC converter has reached a current limit. In case the current limit is reached a signal is sent to the DC-to-DC converter to reduce the current drawn the DC-to-DC converter.

A converter controller controls a switching converter. A current detection circuit generates a current detection signal V_CS that corresponds to a coil current I_L of the switching converter. An error amplifier amplifies the difference between the current detection signal V_CS and an analog signal V_ADIM that indicates a current to be supplied to a semiconductor light source, so as to generate an error signal V_ERR. A hysteresis comparator compares the current detection signal V_CS with an upper threshold signal V_THH and a lower threshold signal V_THL determined according to the error signal V_ERR, and generates a control pulse S_CNT that corresponds to a comparison result. A driver drives a switching transistor according to the control pulse S_CNT.

The invention discloses an overflow and anti-blocking dam structure for water conservancy projects. The overflow and anti-blocking dam structure comprises a dam crest, a dam middle body and a dam baseand is characterized in that a gate pier is arranged on the dam crest, a gate is arranged in the gate pier, a bridge for mounting gate opening and closing equipment is arranged on the gate pier, a control chamber is arranged on the bridge, a first overflow channel and a second overflow channel are arranged in the dam middle body from top to bottom, a third overflow channel and a sand discharge channel are arranged in the dam base from top to bottom, a bottom pier is arranged on the right of the dam base, a lower ogee section is arranged between the bottom pier and the dam crest, a generator set room is arranged on the bottom pier, a hydroelectric generator rotor is arranged on the generator set room, and a spiral conveying belt for conveying sand is arranged on the left in the sand discharge channel. The overflow and anti-blocking dam structure with the sand discharge device and the power generation device is high in sand discharge and flood discharge capacity, large in water storageheight and convenient to maintain.

The present invention discloses an improved inductance-voltage clamping full-bridge soft-switch circuit, comprising a full-bridge converter, a transformer, an output rectifying unit, an inductor, a clamping resistor, a capacitor, a first clamping diode and a second clamping diode. The inductor includes a first winding used as an auxiliary inductor and a second winding used for clamping. The present invention greatly reduces the transient current stress on the clamping resistor by connecting a capacitor in parallel with the clamping resistor connected in series, thereby effectively enhancing the reliability of the clamping resistor and improving the reliability of the overall circuit.

The invention relates to an experimental tank system of a riparian zone, belonging to the field of physical model experiments in hydraulic engineering. The experimental tank system comprises a tank control platform, an experimental composite-type tank, dual-cycle water supply systems, a dual-level flow control system and a switching system. According to the invention, a cyclic surface water supply system and a cyclic underground water supply system which are independent can be used for effectively controlling surface water of rivers to circulate at a higher speed and underground water to circulate at a low speed, and thus river and river bank water flow environments which further accord with natural conditions are provided for a riparian zone experiment; the dual-level flow control system can be used for adjusting and controlling level and flow boundary conditions of the surface water of the rivers and the underground water of the river bank simultaneously, so that the problems that level and flow conditions of the rivers can be independently adjusted only in the traditional river dynamics experiment and level and flow conditions of the underground water can be independently adjusted only in the traditional underground water experiment; and the electronic intelligent switching system can be used for intelligently adjusting and controlling switch-on and switch-off as well as openness of relative power supply switches, valves, tail gates and the like of the experimental tank system. The experimental tank system disclosed by the invention has high automation degree and is provided with an experiment control platform which is simple and easy to operate, so that a user can finish related operations of the experimental tank system of the riparian zone in the same control interface; and the experimental tank system has a fault prompt function and is convenient for emergent measure taking and equipment overhauling.

The invention relates to a mine trackless transport locomotive used for underground subsidiary transport, which comprises a pre driver chamber and a post driver chamber, a driving device, a battery, a load-bearing wheelbarrow, a hoist apparatus, a hydraulic system, an electrical control system, etc. A traction motor in the driving device and a hydraulic pump motor of the hydraulic system both adopt three-phase AC motors, which are provided with AC by the battery through a transducer. The electrical control system comprises of a programmable controller, the transducer, a speed and direction sensor, a pressure sensor, a photoelectric conversion isolation plate, a dashboard, a display board, an intrinsic safety power source, an explosion septal and intrinsic safe electric control box, etc. The traction motor of the trackless motor and the hydraulic pump motor adopt alternating current motors which have the advantages of light weight, small size, low price, convenient maintenance and wide application. The direct current in the battery is transferred into three-phase alternating current by the transducer to reduce attack of starting current on the motors and the battery, prolong the service life of the motors and improve power factor. When the transport locomotive is running declivous, the kinetic energy can be transferred into electric power to charge the battery, so as to realize power regenerative braking.

An improved battery cell having electrodes with active surface areas communicating along an entire edge with conductors thereby minimizing resistance and allowing for communication of electrical current to and from the battery at a high rate with an even discharge from the electrodes. Electrical current is produced by a plurality of electrodes formed of active material adhered to a conductive substrate. The plurality of electrodes is then stacked or wound to a desired configuration with a porous separator separating each adjacent electrode from the other. Communication along the entire edge of the formed electrodes on the conductive substrate with a conductive edge portion of the substrate, provide for maximum current flow in and out of the battery as well as well as reducing thermal concerns in high current applications. Elongated electrical conductors best made from copper are attached to the positive and negative edge portions communicating with substantially the entire active portions of the electrodes to provide a means of electrical current flow to and from the battery.

An inductive power receiver 3 including at least two switches S₁, S₂ connected across a resonant circuit 802, the resonant circuit including an inductance and a capacitance, wherein a first switch S₁ of the at least two switches is configured to switch into a first state based on a first event dependent on a receiver variable; and the first switch is configured to switch to a second state based on a second event independent of a receiver variable.

The present invention discloses a cyclone separation dust cup, which includes a cup body and a cyclone tube, the cyclone tube being provided with an air inlet, an ash ejection outlet, and an air exhaust outlet; and the ash ejection outlet communicates with a dust storage cavity in the cup body, the air exhaust outlet with an air outlet positioned on the cup body through an air exhaust pipe, and the dust storage cavity with the air exhaust pipe. The present invention, with the dust storage cavity communicating with the air exhaust pipe, enables part of the air current entering the cyclone tube to enter the dust storage cavity in the cup body, thus producing suction in the ash ejection outlet of the cyclone tube that can inhale the dust into the dust storage cavity. This makes the impurities with lighter weight (e.g. hair and downy floc), which cannot fall into the dust storage cavity under gravity, be inhaled into the dust storage cavity successfully, thus greatly improving the separating and filtering effect of this cyclone separation dust cup.