422results about How to "Improve voltage stability" patented technology

Chemical modification of a glass and fused silica nanopore surfaces results in surface properties that are ideal for localized bilayer formation over a nanopore and subsequent ion channel recording. With no surface modification, one may form a bilayer supported on the glass capillary extending across the nanopore orifice. Changing the surface properties from that of bare glass to a moderately hydrophobic surface produces a lipid monolayer above the glass and spontaneously yields a bilayer across the nanopore orifice, effectively corralling a single protein ion channel in the lipid bilayer region spanning nanopore orifice. The bilayer structure over the modified nanopore is such that current can only flow through the protein ion channel. The protein ion channel is able to diffuse in the bilayer above the pore opening, but cannot leave this area to enter the lipid monolayer. The bilayer formed across the nanopore orifice exhibits high electrical breakdown voltage, is stable to mechanical vibrations, and is long lived. Resistance through the protein channel can be measured electrically and is exploited for stochastic single-molecule detection. Protein ion channels can be inserted and removed from the bilayer by adjusting transmembrane pressure, and adapter molecules can be electrostatically trapped in the ion channel by applying high transmembrane voltages.

The present invention discloses an LDO (Low DropOut) linear voltage regulator, which is based on an NMC (Nested Miller Compensation) architecture and can be capacitor-free, wherein an active resistor is added to the feedback path of the Miller compensation capacitor to increase the controllability of the damping factor, solve the problem of extensively using the output capacitor with a parasitic resistance, and solve the problem that a compromise must be made between the damping factor control and the system loop gain. Further, the present invention utilizes a capacitor-sharing technique to reduce the Miller capacitance required by the entire system and accelerate the stabilization of output voltage without influencing stability.

The invention discloses a method for statically analyzing voltage stabilization of a VSC-HVDC (Voltage-Sourced Converter-High Voltage Director Current) containing AC and DC system. Aiming at the problem of voltage stability, through determining a tide equation and a converter equation of the VSC-HVDC AC and DC system and considering the change of a load and a generator output, a tide equation containing parameters is formed and a static model of the VSC-HVDC AC and DC hybrid system is established; and the static model is analyzed by adopting a continuous tide method based on a uniform iteration method, and the influence of a VSC-HVDC element on the voltage stability of the system is researched. The invention lays a foundation for further researching the voltage stability characteristic ofthe VSC-HVDC AC and DC hybrid system.

A liquid crystal alignment solution is provided. The liquid crystal alignment solution includes at least one polymer selected from the group consisting of a polyamide acid-polyamide acid polymer represented by formula (A), a polyimide-polyamide acid polymer represented by formula (B) and a polyimide-polyimide polymer represented by formula (C),in which T1 and T2 are each independently a tetravalent organic group; m<n; p<q; r<s; and at least one of D1 and D2 is selected from the group consisting of formulae (1) to (15).

The invention discloses a method and system for multi-target reactive power optimization of electric power systems. The method comprises the following steps of: establishing a multi-target reactive power optimization model; generating positions of N initial bird nests by utilizing Kent chaotic mapping, taking the positions of the N bird nests as initial populations, calculating a fitness value of each bird nest, establishing an external file set according to a Pareto dominance relation, updating the positions of the bird nests according to self-adaptive weights, updating the external file set according to the dominance relation and calculating a congestion distance to control the capacity of the file set; carrying out a differential evolution operation on each bird nest and updating the external file set; and when an iteration termination condition is satisfied, outputting an optimum Pareto optimal solution set. According to the method and system, a plurality of target functions are considered, so that the disadvantages that the traditional method is used for converting a plurality of targets into a single target and is difficult to determine the weight coefficients are optimally overcome; an improved cuckoo search algorithm is high in convergence rate, high in precision and good in individual diversity; and the obtained optimal solution set has favorable diversity and uniform distributivity, and can be well adapted to solving the multi-target reactive power optimization problems of the electric power systems.

The invention provides a method of optimal control of wind power plant reactive voltage. On the premise of guaranteeing the safe running of a wind power plant by effectively utilizing multiple reactive devices and voltage regulating measures in the wind power plant, quick response is carried out on the voltage instructions of the wind power plant given by a scheduling mechanism. The optimal control model of the reactive voltage of the wind power plant is built with the maximum reactive margin of the reactive devices in the wind power plant and the highest stable level of machine end voltage of a wind turbine generator as a comprehensive aim and with voltage constraints of the combined network point of the wind power plant, the balance constraints of the active power and reactive power of a node and the constraints of the top limitation and the bottom limitation of a variable and the like as constraint conditions, solution is carried out by using an optimization algorithm, the obtained optimal control instructions of the reactive power of the wind power plant are given to various reactive devices in the wind power plant to execute. The method of the optimal control of the wind power plant reactive voltage harmonizes various reactive device with adjustable high speed and low speed in the wind power plant, the reactive power of the combined network point meets scheduling instructions, meanwhile the reactive margin in the wind power plant is enabled to be maximum, the voltage stable level in the wind power plant is enabled to be highest, and transmission losses are reduced.

The present invention discloses an LDO (Low DropOut) linear voltage regulator, which is based on an NMC (Nested Miller Compensation) architecture and can be capacitor-free, wherein an active resistor is added to the feedback path of the Miller compensation capacitor to increase the controllability of the damping factor, solve the problem of extensively using the output capacitor with a parasitic resistance, and solve the problem that a compromise must be made between the damping factor control and the system loop gain. Further, the present invention utilizes a capacitor-sharing technique to reduce the Miller capacitance required by the entire system and accelerate the stabilization of output voltage without influencing stability.

A lithium metal battery including: a lithium negative electrode including lithium metal; a positive electrode; and an electrolyte interposed between the lithium negative electrode and the positive electrode, wherein the electrolyte contains non-fluorine substituted ether, which is capable of solvating lithium ions, a fluorine substituted ether represented by the following Formula 1, and a lithium salt, wherein an amount of the fluorine substituted ether represented by Formula 1 is greater than an amount of the non-fluorine substituted ether,R—{O(CH2)a}b—CH2—O—CnF2nH  Formula 1wherein R is —CmF2mH or —CmF2m+1, n is an integer of 2 or greater, m is an integer of 1 or greater, a is an integer of 1 or 2, and b is 0 or 1.

An electrode for an energy storage device, including a substrate of at least one metal that forms a native oxide layer; and a treated layer formed on the substrate from the native oxide layer, the treated layer having a resistance that is less than the resistance of a native oxide layer. In some embodiments, the treated layer possesses at least one of the following properties: includes one or more dopants, is thinner than the native oxide layer, has a carbon coating that is applied to the treated layer which improved adhesion characteristics, and others. Further, there is an energy storage device having two or more of such electrodes, wherein the device has a low initial ESR and / or a low ESR at various intervals. Moreover, disclosed is a low resistance metal including a substrate of at least one metal that forms a native oxide layer; and a treated layer formed on the substrate from the native oxide layer, the treated layer having a resistance that is less than the resistance of a native oxide layer. Additionally, methods relating to the above devices are also disclosed.

The invention relates to an automatic low-frequency low-voltage load-reduction centralized optimization control system for power systems in the technical field of industrial control. The control system comprises a data acquisition module, an off-line computation module and an on-line control module, wherein the data acquisition module acquires EMS data through a data server, and acquires the operation information of a system through data acquisition devices arranged on a PMU, a UFLS device and an important element, as well as the operation condition of every element; the off-line computation module computes voltage stability boundary of nodes, as well as load frequency response functions; and the on-line control module computes load shedding amount, determines the order of UFLS movements, transmits control instructions to the UFLS device, and determines a next control instruction according to the information fed back by the UFLS. The control system is based on the parameters of the real-time changes of the power systems, and determines the movement order and load shedding amount of the UFLS device of a whole network, thereby speeding up the frequency recovery of the systems and improving the operation stability of the systems.

The invention discloses a depth control method for an energy storage power station participating in primary frequency modulation of a power grid, which is characterized in that a grid-connected inverter of the energy storage power station is equivalent to a synchronous voltage source with excitation control and speed regulation control, the energy storage power station adopts a control strategy ofa synchronous machine third-order model, and the frequency modulation depth of the battery energy storage power station participating in the primary frequency modulation of the power grid by settinga difference adjustment coefficient sigma<battery>% of the energy storage power station according to a flexibility index and a static frequency characteristic of the battery energy storage power station. The invention further discloses a contribution calculation method for the energy storage power station participating in primary frequency modulation of the power grid. The frequency modulation depth of the energy storage power station participating in system primary frequency modulation is controlled, so that the rated power, the rated capacity and the climbing rate of the energy storage powerstation are reasonably configured to stabilize the steady-state frequency of the system after primary frequency modulation in a reasonable range, the frequency stability and the voltage stability ofthe energy storage power station for supporting grid connection of the new energy system are improved, a contribution factor lambda is defined, and the importance of the energy storage power station in the power grid system to frequency modulation is analyzed.

The present invention provides compositions, formulations and methods providing for the effective dissolution of inorganic fluorides in solvents via incorporation of a dissociating agent component. Dissociating agents of the present invention participate in chemical reactions in solution, such as complex formation, acid-base reactions, and adduct formation reactions, that result in enhancement in the dissolution of inorganic fluorides in a range of solvent environments. Dissociating agents comprising Lewis acids, Lewis bases, anion receptors, cation receptors or combinations thereof are provided that significantly increase the extent of dissolution of a range of inorganic fluorides, particularly inorganic fluorides, such as LiF, that are highly insoluble in many solvents in the absence of the dissociating agents of the present invention.

The invention discloses a high permeability new energy power grid connection system and stability control method which belongs to the field of a new energy power system. When new energy has high permeability (50% to 100%), a power grid connection system is composed of a prime mover, a motor and a synchronous generator, or is composed of a motor and a synchronous generator. Rotors of the units are coaxially connected. New energy power is transmitted and converted to power the motor. According to the invention, the method is different from a traditional new energy direct grid connection method; a high permeability new energy power system has enough inertia; the frequency stability of the system is improved; the synchronous generator is retained to effectively damp system oscillation; through voltage and reactive power control, the power angle and the voltage stability of the system are improved; the peaking capacity of traditional thermal power and hydropower units and the like is retained; and through coordinated control of the motor, the synchronous generator and the prime mover, the dynamic regulation characteristic of the system is improved.

The present invention discloses deuterated semiconducting organic compounds. The deuterated semiconducting organic compounds comprise at least one partially or fully deuterated non-conjugated portion linked to the conjugated portion. The mentioned deuterated semiconducting organic compounds can be used in optoelectronic devices, such as light-emitting devices and photodiodes, with enhanced performance and lifetime. The deuterated semiconducting organic compounds of this application can be employed as emissive layer, charge-transporting layer, or energy transfer material in organic light-emitting devices.

The invention discloses a method for achieving power grid light storage system capacity configuration and optimization distribution. The method for achieving the power grid light storage system capacity configuration and the optimization distribution includes the following steps: (1) a photovoltaic electricity generation grid-connected system model is established; (2) the model is conducted with load flow calculation, and whether power grid operation meets constraint conditions is judged; if the power grid operation meets the constraint conditions, a next step is conducted; and if the power grid operation does not meet the constraint conditions, the step (1) is returned to, and a power grid parameter is modified; (3) initial emulating calculation is conducted to obtain an index value before energy storage system access; (4) N access points of an energy storage system are conducted with emulating calculation, so that an index value after the access is obtained; (5) an index of each access point is conducted with normalization processing, so that an objective subfunction is generated; (6) N objective functions with variable balance coefficients are obtained through the generated objective subfunction; (7) an assessment result is obtained through objective function computational analysis; and (8) the assessment result is conducted with optimal value choices. According to the method for achieving the power grid light storage system capacity configuration and the optimization distribution, a power grid is provided with fast active and reactive power support. The power grid voltage stability level is improved, and the network loss is lowered. Besides, the accuracy and the generality are improved.

The present invention discloses a method of optimizing the static safe and stable operation limit of an electric power system. The method comprises the steps of using a BPA electric power system calculating and analyzing software to analyze an original data report containing the network structure and operation data of an evaluated electric power system; then carrying out the BPA power flow calculation on the data in the original data report; if the BPA power flow calculation is not convergent, correcting a control variable or a constrained condition until the BPA load flow calculation is convergent; then carrying out the N-1 power flow calculation; if the N-1 power flow calculation is not convergent, carrying out the N-1 optimal power flow calculation until the N-1 optimal power flow calculation is convergent, and outputting an N-1 power flow calculation report; and then using the data in the N-1 power flow calculation report to substitute for the data in the original data report, so that the situation that the evaluated electric power system is located in a power grid operation manner of the static safe and stable operation limit is guaranteed.

The invention relates to a dynamic reactive compensation mounting point optimization method for a multi-direct-current centralized infeed receiving end power grid. According to the method, a simulated computation of a dynamic voltage change process is demonstrated in a graphical way. The method comprises the following steps: excavating a voltage stability weak region in a multi-infeed direct-current receiving end area; performing voltage response computation under point-by-point reactive change on alternating-current and direct-current nodes in the weak region by adopting a transient stability computation procedure for a power system; establishing a direct-current weight coefficient model by taking direct-current impedance and direct-current rated volume as parameter factors according to direct-current mutual influences, combining with a corresponding voltage computation result, computing the reactive node investment effect indexes of the weak region, and sequencing according to the indexes; and mounting a dynamic reactive compensation device on the node at a first order, sequencing once again, and repeatedly circulating till the required quantity of sequencing mounting points is satisfied. A final result is the node sequence of dynamic reactive compensation mounting, appropriate cost of the power grid is ensured, and the voltage stability of the multi-direct-current centralized infeed receiving end power grid is improved.

A method predicts a voltage collapse in a micro-grid connected to a power distribution network by measuring states at a point of common coupling of the micro-grid, and a connected bus of the power distribution network connected to the micro-grid through a connection link. Then, it is determined whether a reactive power generation limit of the micro-grid is reached based on the states, and if no, repeating the measuring, and otherwise determining parameters of the connection link using the measurements. A static voltage stability margin index is determined, and a voltage stability margin index is predicted using the static voltage stability margin index and a forecast of future load variations in the micro-grid. Then, it is determined whether the voltage stability margin index is smaller than a threshold, and if no, repeating the measuring, determining and predicting steps, and otherwise if yes, signaling a control action indicating the voltage collapse.

The invention relates to a system control method for a dynamic reactive power compensation device and belongs to the technical field of grid safety and stable control of a power system. The method includes: according to voltage and current of the dynamic reactive power compensation device accessed to the power transmission grid, switching states of parallel compensation equipment in a substation and manual setup of operators, quickly calculating reactive power requirement values of each functional mode of the dynamic reactive power compensation device, and determining which output of the functional modes can be selected by the dynamic reactive power compensation device to serve as reactive power reference instruction values. The method has the advantages of distinct control structure, simplicity in implementation and the like and overcomes the defect of single control function of a traditional control method. In addition, the control method can be applied to stable control of the power system, and voltage stability and dynamic stability of the power transmission grid can be improved.

A capacitor structure may be incorporated into an interposer or substrate associated with an IC chip to stabilize the input / output signals, such as power and ground, between the IC chip and a printed circuit board. In accordance with one embodiment, the capacitor structure may include a plurality of individual capacitors connected together to form a monolithic capacitor blade having a length, width, and height, wherein each of the length and height of the blade spans multiple of the individual capacitors. The blade includes multiple electrical conductive paths extending the height of the capacitor blade. According to another embodiment, the capacitor structure includes multiple interleaved power and ground layers separated by insulating layers. The power layers connect to power leads and the ground layers connect to ground leads.

The invention provides a lithium ion battery, a positive active material thereof and a preparation method of the positive active material. The positive active material of the lithium ion battery comprises a first positive active material and a second positive active material, wherein the general formula of the first positive active material is Li1+aNixMnyMzO2, M is at least one of Co, Al, Mg, Zr, Ti, Ca, V and Sr, a is smaller than or equal to 0.1 and larger than or equal to 0, and a+x+y+z is equal to 1, x is smaller than 0.8 and larger than 0, y is smaller than 0.6 and larger than 0, and z is smaller than 0.6 and larger than 0; and the second positive active material is wrapped on the surface of the first positive active material and has an NASICON structure, the universal formula of the second positive active material is LibV2-uM'u(PO4)3, b is smaller than or equal to 3 and larger than 2, u is smaller than or equal to 0.3 and larger than or equal to 0.1, and M' is at least one of Fe, Mn, Ni, Ti, Al and Mg. According to the invention, the positive active material of the lithium ion battery can improve the safety performance, the high voltage stability and the cycling performance of lithium transition metal oxide, and the specific capacity and the energy density of the whole positive active material can not be reduced; and in addition, through controlling the voltage, the overcharge of the lithium transition metal oxide can be prevented, and the structure collapse of the overcharged lithium transition metal oxide is effectively restrained, so that the safety performance is improved.

The invention relates to a direct current heavy current thawing device with the function of a static type dynamic reactive power compensation, which belongs to the corollary equipment technical field of a high-low voltage power supply and distribution system; the invention is characterized in that a three-phase alternating current wave filter is connected to a generatrix in parallel; an intermediate point of a three-phase high voltage heavy current controlled silicon valve is connected with the generatrix through a three-phase alternating current reactor; the negative electrodes of the controlled silicon valve are selectively connected with the generatrix through the three-phase alternating current reactor; the positive electrode and the negative electrode of the same phase and the same electrodes of the different phases of the three-phase high voltage heavy current controlled silicon valve are respectively in selective connection; a trigger signal emitted by a controller triggers the conduction of the three-phase high voltage heavy current controlled silicon valve through optical fibers. The direct current heavy current thawing device combines direct current heavy current thawing technology and static type dynamic reactive power compensation technology, realizes corresponding functions according to different requirements on the spot for electricity consumption, can obviously reduce the corollary equipment cost of the power supply and distribution system, effectively improves the utilization rate of the equipment, can be used as a direct current heavy current thawing device with controllable current when line freezes and can be also used as a static type dynamic reactive power distribution device.

The invention discloses a method of forming a distributed energy storage system by a small hydropower cluster. The method comprises steps: a total net load value PLj(t) of all small hydropower stations at a tth time in an energy storage cycle T is acquired; according to an optimization objective, the total net load value PLj(t) and planned load pi(t) of an ith small hydropower station, the actual load pfci(t) of the ith small hydropower station is acquired; and according to the actual load pfci(t) of the ith small hydropower station, optimal efficiency control is carried out on a water pumping and water storing device of the ith small hydropower station, and the ith small hydropower station is made to operate under the optimal efficiency according to the actual load pfci(t), wherein the water pumping and water storing device is a hydraulic turbine, a water pump or a reversible hydraulic turbine. Through carrying out improvement on the small hydropower stations and using an energy management unit to manage the small hydropower stations in a unified mode, the multiple small hydropower stations can form a large energy storage system capable of power generation and energy storage, the problems of the operation efficiency and the utilization of the small hydropower stations can be solved, and the regulation capability of the power grid is improved.

The invention provides a power-frequency online anti-icing de-icing method for an electrified railway contact network. The method comprises the steps as follows: A, the head end and the tail end of any power-supply arm of an electrified railway traction substation are respectively connected with a head-end dynamic reactive compensation device and a tail-end dynamic reactive compensation device; and a temperature sensor is arranged on a contact network and connected with a controller of the head-end dynamic reactive compensation device and the tail-end dynamic reactive compensation device; and B, the temperature sensor monitors the temperature of the contact network, and when the detected temperature is lower than 0 DEG C, the controller controls the head-end and the tail-end dynamic reactive compensation devices to enter into an anti-icing de-icing working state and specific current is generated on a contact net for anti-icing and de-icing. The method is used to carry out automatic online anti-icing and de-icing under the condition that the railway is in a continuous running state and the power supply is not influenced, so that the contact network is not frozen in freezing rain, ice and snow and extreme weathers, thereby ensuring the safety of train operation.

The invention provides a power distribution network multi-objective probabilistic reactive power optimization method. The method includes the following steps that: a stochastic model is constructed according to the predetermined stochastic factors of a power distribution network; probabilistic power flow is calculated, so that the probabilistic density function of node voltage can be obtained; the voltage entropy of the power distribution network is calculated according to the probabilistic density function of the node voltage; and a multi-objective probabilistic reactive power optimization model is constructed and solved. With the power distribution network multi-objective probabilistic reactive power optimization method provided by the technical schemes provided by the invention adopted, the probabilistic distribution of the node voltage is more centralized compared with probabilistic distribution obtained by using a single-objective reactive power optimization method, and the voltage percent of pass of a system can be improved.

A transistor and method of manufacture thereof. A semiconductor workpiece is doped before depositing a gate dielectric material. Using a separate anneal process or during subsequent anneal processes used to manufacture the transistor, dopant species from the doped region of the workpiece are outdiffused into the gate dielectric, creating a doped gate dielectric. The dopant species fill vacancies in the atomic structure of the gate dielectric, resulting in a transistor having increased speed, reduced power consumption, and improved voltage stability.