39results about How to "Reduce voltage offset" patented technology

Bandgap reference (BGR) circuits and methods are described herein for providing high accuracy, low power Bandgap operation when using small, low voltage devices in the analog blocks of the BGR circuit. In some cases, chopped input stabilization and dynamic current matching techniques may be combined to compensate for input voltage offsets in the operational amplifier portion and current offsets in the current mirror portion of the Bandgap circuit. When used together, the chopped stabilization and dynamic current matching techniques provide a significant increase in accuracy, especially when using small, low voltage devices in the analog blocks to reduce layout area and support low power supply operation (e.g., power supply values down to about 1.4 volts and below).

The invention discloses a control method for a three-phase PWM rectifier suitable for power grid waveform distortion. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion mainly includes that extracting a current reference signal under input voltage distortion and unbalanced disturbance, and actively injecting negative-sequence current, improved dead-beat inner current loop which is forecast through combining with linear extrapolation, and outer direct voltage loop performed with active disturbance rejection control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion plays roles of inhibiting the harmonic wave of the input current of the PWM rectifier, injecting proper negative-sequence current to eliminate the secondary power pulse of the output direct current voltage of the PWM rectifier, improving the transient response of the output direct current voltage, and compensating the influences of all kinds of delay on the dead-beat control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion is capable of obviously reducing the secondary wave of the output direct current voltage under the disturbance of the input harmonic wave and unbalanced voltage, improving the transient response speed of the PWM rectifier, reducing the transient offset of the direct current voltage, and improving the system control precision.

The invention relates to a voltage peak detection circuit, comprising a differential amplifying unit, a common-source amplifying unit and a source following unit; and the operating method thereof includes signal acquisition, signal comparison, signal amplification, signal source following output, peak voltage following and recording. The invention has the advantages that: (1) peak of high speed voltage signal can be detected; (2) voltage detuning of circuit is reduced; (3) circuit structure is simple, no extra compensation is required, and practicability is strong.

An adjustable bandgap reference voltage comprises means for generating current proportional to absolute temperature comprising first means connected to terminals of a core and designed to equalize voltages across the terminals, means for generating a current inversely proportional to absolute temperature connected to the core, and an output module designed to generate the reference voltage; the first processing means comprise a first amplifier possessing a stage, biased by the current inversely proportional to absolute temperature, arranged according to a folded setup and comprising first PMOS transistors arranged according to a common-gate setup, and a stage whose input is connected to the amplifier output and whose output is connected to the first stage input and to a terminal of the core, the second generating means comprise a follower amplifier setup connected to a terminal of the core and separated from the first amplifier, the output module is connected to the feedback stage.

With regard to the problem of overcharge and over-discharge due to different initial states-of-charge (SOC) of a DC microgrid during the process of system power supplement or absorption of a pluralityof energy storage units and the defect that the load current of an energy storage system cannot be reasonably allocated in real time by a traditional droop control method, a novel storage SOC index function-based droop control method is research and developed. The difference from a traditional method lies in that a droop coefficient can be changed in real time according to the change of the SOC index function, so that the storage battery SOC and the load current reach a balance state, and the effects of equally dividing the load and prolonging the service lifetime of the storage battery are finally achieved.

An integrated circuit system, and a method of manufacture thereof, including: an integrated circuit die; a non-volatile memory cell in the integrated circuit die and having a bit line for reading a data condition state of the non-volatile memory cell; and a voltage clamp in the integrated circuit die, the voltage clamp having a semiconductor switch connected to the bit line for reducing voltage excursions on the bit line.

The invention relates to a voltage frequency cooperative control method of a double-feed asynchronous wind turbine generator in a micro grid. A frequency control module is controlled through a rotor converter, when the frequency is changed in the micro grid, a virtual inertia link in the frequency control module can quickly respond to an f-P droop control link, and the system frequency is stabilized to a new stabilizing point. By adding an accessary DFD logic module in an existing rotor converter for voltage control, the capability for the double-feed synchronous wind turbine generator to provide voltage frequency support in the micro grid is improved. The method can makes a DFIG automatically inhibit micro grid voltage fluctuation brought by power change of the DFIG, when the droop control causes that the micro grid voltage exceeds a limit, reactive power output of the DFIG can be further increased, and voltage deviance of the micro grid is lowered; meanwhile, the voltage frequency control module guarantees power distribution of the DFIG and other distributed power sources in the micro grid, peer-to-peer control of the micro grid can be achieved, and the voltage frequency stability of the micro grid is improved.

The invention relates to a branch voltage stability analysis based selection method for a reactive power compensation point of a microgrid. The method comprises the steps of determining installed capacities of wind power generation and photovoltaic power generation in the microgrid and the magnitude and the property of a load which is connected with a microgrid system; determining a boundary constraint of the microgrid system and all items of data of all branches and all nodes in the microgrid system; calculating and sequencing voltage stability L indexes of all branches according to detailed data of all branches and all nodes; selecting a reactive power receiving end node of a main weak branch of a weak area as the reactive power compensation point; and calculating and comparing network losses and voltage excursions of the microgrid system before and after compensation, and verifying the correctness of the point selection method. According to the method, the reactive power compensation point in the microgrid can be selected accurately on the basis of the branch voltage stability, the influence of change of the microgrid operation mode and the output volatility of a micro source is low, the method is good in applicability and economy and capable of effectively reducing network losses and voltage excursions of the microgrid.

An auto-nulled bandgap reference system employing a substrate bandgap reference circuit with primary and auxiliary amplifiers and a switching circuit which in a first mode develops a voltage to null the offset and noise errors of the auxiliary amplifier and then in the second mode uses the nulled auxiliary amplifier to develop a voltage to null the offset and noise errors of the primary amplifier; and a strobe circuit including an output storage device and a strobe control circuit for periodically powering up a bandgap reference circuit to charge the output storage device and powering down the bandgap reference circuit to conserve power.

The invention discloses an optimal scheduling method based on a multi-energy complementary micro-grid and an active power distribution network. The method comprises the following steps: respectively establishing an optimal scheduling target model of the multi-energy complementary micro-grid and an optimal scheduling target model of the active power distribution network; establishing an optimization scheduling constraint condition; establishing a double-layer optimization model by taking the optimization scheduling target model of the multi-energy complementary micro-grid and the optimization scheduling target model of the active power distribution network as optimization targets and the optimization scheduling constraint conditions as constraint conditions; and solving the double-layer optimization model, and carrying out optimization scheduling operation based on a solving result. According to the method, coordinated optimization of the multi-energy complementary micro-grid and the active power distribution network is realized, various energy requirements in the micro-grid can be met, gradient utilization of different energy sources is realized, the operation state of the active power distribution network can be considered, support is provided for safe operation of the power distribution network, and the energy benefit of a user-side comprehensive energy system can be improved.

A sensor device comprising a substrate, the substrate comprising one or more magnetic sensor elements; a first elastomeric material on top of the one or more magnetic sensor elements; a magnetic layer comprising a soft magnetic metal alloy deposited by electroplating or by sputtering on top of the first elastomeric material; and optionally a second elastomeric material on top of the magnetic layer. The substrate may be a CMOS device with IMC encapsulated between two polyimide layers. The magnetic material may be annealed at 250° C. to 295° C. using a constant or rotating magnetic field having a strength in the range from 100 to 300 mTesla. The soft magnetic alloy is arranged as Integrated Magnetic Concentrator (IMC).

A reactive power flow optimization method based on an AVC system includes the following steps: (1) building a mathematical model with active loss, voltage stability margin and voltage excursion of the system as a target function to fully guarantee the voltage stability margin and reduce voltage excursion while considering the economy; (2) setting constraint conditions including equality constraint and inequality constraints; (3) adopting an NSGA-II algorithm to solve a target function to enable an operation result to be converged on the global optimal solution; (4) making a control strategy according to the optimal solution of the target function. The method has good safety, economy and high adaptability.

A method and device for correcting a voltage-lambda characteristic curve of a two-step lambda oxygen sensor in an exhaust tract relative to a reference-voltage lambda characteristic curve of the oxygen sensor; a deviation in the characteristic curve relative to the reference characteristic curve at lambda=1 being corrected; based on a value pair on the reference-voltage lambda characteristic curve, the composition of the air-fuel mixture supplied to the engine being changed toward lambda=1; the actual value of lambda being inferred from the change in the composition of the air-fuel mixture. The adaptation of the operating parameters of the oxygen sensor is intended to eliminate the cause of a deviation. Efforts are not merely directed to adapting the deviation to the reference characteristic curve by shifting the voltage-lambda characteristic curve. Effects, which may lead to tolerance- or aging-induced falsifications of the voltage-lambda characteristic curve, can be fully compensated.

The disclosure illustrates a display device comprising: pixels arranged in a matrix form; image signal lines providing data signals to the pixels; scan signal lines crossing the image signal lines; a gate driver circuit configured to output a scan signal to the plurality of scan signal lines, and drive the scan signal lines by the scan signal; and a control circuit configured to control the gate driver circuit through a control signal comprising voltage waveform with voltage variation cycles. When a scan cycle of the scan signal is started, a voltage level of the scan signal non-vertically rises from a first voltage level to a second voltage level, and the voltage level of the scan signal is maintained at the second voltage levels, and when the scan cycles is ended, the voltage level of the scan signal non-vertically falls from the second voltage level to the first voltage level.

The invention provides a ground wire short-circuit protection circuit, a ground wire is connected between a sensor and a controller, the protection circuit comprises an execution module and a control module, the execution module is connected in series in the ground wire, and the control module is connected with the ground wire and used for detecting whether the voltage value of the ground wire is abnormal or not. The control module is connected with the control end of the execution module and used for controlling on-off of the execution module, if the voltage value of the ground wire is abnormal, the control module disconnects the execution module to disconnect the ground wire, and if the voltage value of the ground wire is normal, the control module connects the execution module to connect the ground wire. According to the invention, the problem that wrong trigger protection is easy to cause due to large resistance change of the thermistor along with temperature change is solved. The invention further provides an automobile motor controller and an electric automobile.

The invention relates to a starting control method and device of a power transmission system, a flexible inverter station, the power transmission system and a storage medium. The method comprises the steps that after the flexible inverter station is controlled to be unlocked, the output electrical parameter of the flexible inverter station is controlled to be a target parameter smaller than a rated electrical parameter; then, the conventional inverter station is controlled to be unlocked, the conventional inverter station is indicated to send an unlocking signal to the conventional rectifier station after being unlocked, the conventional inverter station normally executes phase commutation operating under the target parameters, and the unlocking signal is used for unlocking the conventional rectifier station; that is to say, the method can control the output electrical parameters of the flexible inverter station after the flexible inverter station is unlocked so as to avoid that the power of the flexible inverter station flows to the conventional inverter station too much after the conventional inverter station is unlocked due to the fact that the output electrical parameters of the flexible inverter station are too large. Therefore, by the adoption of the method, the starting efficiency of the power transmission system can be greatly improved.

The invention discloses low-voltage three-phase-imbalance adjusting equipment and a power supply system thereof. The low-voltage three-phase-imbalance adjusting equipment comprises a central control device and is characterized in that the input end of the central control device is electrically connected with a three-phase electric quantity meter, and the three-phase electric quantity meter is parallelly connected into a power grid; the central control device is connected with a DSP chip, a drive module for driving a three-phase adjusting unit and a communication module, the three-phase adjusting unit comprises a plurality of separated adjusting units parallelly connected into the power grid, each separated adjusting unit comprises a main contactor K, an LC filter and eight switch module four-leg inverters, each main contactor K is electrically connected with the drive module, and the performance of the LC filter in the separated adjusting unit close to a transformer is larger than thatof the LC filters in the rest of the separated adjusting units. The low-voltage three-phase-imbalance adjusting equipment and the power supply system thereof have the advantages that the transformerand the low-level-configuration secondary side power grid can be monitored in real time, voltage excursion brought by three phase imbalance is lowered, reactive current loss is reduced, and power factor is increased.