111 results about "Mixed potential" patented technology

The invention belongs to the field of gas sensors, and particularly relates to a NASICON-based mixed-potential type H2S sensor with a novel composite metallic oxide sensitive electrode. The NASICON-based mixed-potential type H2S sensor can be used for detecting poisoned gas in the atmospheric environment and consists of a nickel-cadmium alloy heater, an Al3O3 ceramic tube used as an insulating layer, an NASICON ion conductive layer, an Au reference electrode and the sensitive electrode consisting of Au and metallic oxide electrodes. Cobalt chromate doped with manganese is used as the sensitive electrode for the first time, the catalytic activity of the cobalt chromate in electrochemical reaction is increased owning to the manganese, the efficiency of electrode reaction at a three-phase boundary is improved, electron transfer rate is effectively increased, electrochemical reaction rate is greatly increased, and the purpose of increasing sensitivity is achieved. The sensitivity of the sensor using CoCr1.2Mn0.8O4 as the sensitive electrode is far higher than that of a sensor using CoCr2O4 without manganese as a sensitive electrode.

The invention belongs to the technical field of gas sensors, and particularly relates to a YSZ base mixed-potential type NO2 sensor based on a hierarchical In2O3 sensing electrode and a preparation method of the YSZ base mixed-potential type NO2 sensor. The sensor can be mainly applied to the detection of automobile exhaust, and sequentially comprises an Al2O3 ceramic plate with a Pt heating electrode, a YSZ baseplate, a reference electrode and a sensing electrode, wherein the reference electrode is strip Pt; the sensing electrode is strip In2O3; the reference electrode and the sensing electrode are discrete with each other and symmetrically arranged at the two ends of the upper surface of the YSZ baseplate; the lower surface of the YSZ baseplate is bonded with the Al2O3 ceramic plate with a Pt heating electrode. According to the invention, the YSZ baseplate is used as an ion conducting layer, In2O3 with high electrochemicalcatalytic activity is used as the sensing electrode, and the micro appearance of the sensing electrode material is changed through different calcination temperatures (800 DEG C to 1200 DEG C), so that the purpose of improving the sensitive property is achieved.

The invention discloses a mixed-potential type NO2 sensor with a laser-machined YSZ (yttria-stabilized zirconia) substrate serving as a conductive layer and a preparation method for the mixed-potential type NO2 sensor and belongs to the technical field of gas sensors. The mixed-potential type NO2 sensor consists of an Al2O3 ceramic plate with a Pt heating electrode, the YSZ substrate with a mesh-strip structure, a reference electrode and a sensitive electrode, wherein strip-type Pt is adopted as the reference electrode; strip-type NiCr2O4 is adopted as the sensitive electrode; the two electrodes are symmetrically arranged at two ends of the upper surface of the YSZ substrate; the lower surface of the YSZ substrate is adhered to the Al2O3 ceramic plate; a strip distance of the mesh-strip structure is 130-240 microns; the mesh-strip structure is 10-25 microns deep; each strip is 50-80 microns wide; electrode leads are prepared on the reference electrode and the sensitive electrode. The sensor is mainly used for detecting automobile exhaust. Due to the mesh-strip structure on the surface of the YSZ substrate, contact between the gas to be detected and an electrolyte is enlarged, reaction active sites are increased, and the aim of improving the sensitivity of the sensor is fulfilled.

The invention discloses an improved Gaussian mixed potential probability hypothesis density filtering method. The method comprises the following steps: 1) forming a target state set and a target strength function; 2) initializing probability hypothesis density and potential distribution of an initial target; 3) carrying out predication on the probability hypothesis density and potential distribution of the target state set at the time of k+1 to obtain probability hypothesis density and potential distribution at the time of k+1; 4) updating the probability hypothesis density and potential distribution of the target state set at the time of k+1 to obtain probability hypothesis density and potential distribution at the time of k+1, carrying out unbiased conversion on a true covariance matrix and true deviation, and setting an ellipsoid threshold value to simplify a measurement set and reduce observation number of a current observation set; 5) carrying out trimming and combining on Gaussian items of the target strength function, and extracting target state estimation and carrying out performance evaluation; and 6) repeating the steps 3)-5), and tracking the target until the target disappears. The method facilitates direct application of radar data information, and reduces calculation amount of a filter.

The invention discloses a YSZ-based mixed-potential type NH3 sensor with Ni3V2O8 serving as a sensitive electrode and a preparation method of the YSZ-based mixed-potential type NH3 sensor with the Ni3V2O8 serving as the sensitive electrode, and belongs to the technical field of gas sensors. The sensor is mainly used for detecting ammonia in automobile tail gas. The sensor consists of an Al2O3 ceramic plate with a Pt heating electrode, a YSZ substrate, a reference electrode and the sensitive electrode, wherein the reference electrode is made from strip-type Pt; the sensitive electrode is made from strip-type Ni3V2O8; the two electrodes are independent and are symmetrically prepared at two ends of the upper surface of the YSZ substrate; the lower surface of the YSZ substrate is adhered to the Al2O3 ceramic plate. YSZ serves as an ion conductive layer; the Ni3V2O8 with the high electrochemical catalysis activity is used as the sensitive electrode; the microstructure of a sensitive electrode material is changed under different calcining temperatures (800 DEG C, 1,000 DEG C and 1,200 DEG C), and the aim of high sensitivity is achieved.

The invention relates to a method for potential controlled selection separation of copper refinery ash. The copper refinery ash is screened and then subjected to oxidizing leaching in a sulfuric acid system. An oxidizing agent is added to control the metal ion mixed potential of slurry, copper, arsenic, zinc and other metal are dissolved into a solution, and lead, bismuth and other metal precipitate and enter leaching residues. The metal ion mixed potential and the pH value of a leachate are simultaneously controlled, so that copper sulfide concentrate is produced through precipitation. The metal ion mixed potential and the pH value of copper-removed liquid are simultaneously controlled, so that arsenic sulfide products are produced through precipitation. The metal ion mixed potential and the pH value of arsenic-removed liquid are simultaneously controlled, so that zinc sulfide concentrate is produced through precipitation. Zinc-removed liquid is subjected to wastewater treatment and then discharged after reaching the standard. According to the method, the potential controlled oxidizing leaching and potential controlled sulfide precipitation ways are simultaneously adopted for recovering valuable metal step by step, the selection separation effect, which cannot be achieved by independently using the ways, of the valuable metal in the copper refinery ash is achieved, and the leaching rates of copper, arsenic and zinc are larger than 98.0%.

The invention discloses a copper soot smelting and separation combined treatment method. Copper soot is leached in water solution after ball milling to a requested particle size; sodium sulfide is added to control the metal ion mixed potential of whole pulp at a requested numerical value; meanwhile, sulfuric acid is added to adjust the pH value of the pulp to keep at a requested numerical value; after the solution potential is stabilized, and the stirring is continued by a period of time, the filtration is performed; the leaching liquid controls the metal ion mixed potential and the pH value; arsenic sulfide and zinc sulfide precipitates are respectively prepared to send to waste water for treatment; and leaching slag directly performs flotation to prepare copper concentrate and flotation tailing after alkaline ball milling conversion. The method recovers valuable metal step by step by using a control potential vulcanization leaching and beneficiation combined method; the processes are tightly associated; and single process cannot achieve the desired effect of selection and separation of the valuable metal in copper soot. The leaching rates of arsenic and zinc both reach above 95.0%; and the direct recovery rate of copper reaches above 98.0%.

The invention belongs to the technical field of a gas sensor, and particularly relates to a Co3V2O8 sensing electrode and three-dimensional three-phase boundary-based high-performance YSZ electrode mixed potential NO2 sensor and a preparation method thereof. The sensor is mainly used for detection of automobile tail gas. The sensor sequentially comprises an Al2O3 ceramic plate with a Pt heating electrode, an YSZ substrate, a reference electrode and a sensing electrode; the reference electrode is a strip-shaped Pt, the sensing electrode is a mixture of strip-shaped Co3V2O8 and YSZ, the two electrodes are separately and symmetrically prepared on two ends of the upper surface of the YSZ substrate, and the lower surface of the YSZ substrate and the Al2O3 ceramic plate with the Pt heating electrode are adhered together. The area of the three-phase boundary of a sensing electrode material is changed by changing the addition amount of the YSZ through taking the YSZ substrate as an ion conductive layer and the Co3V2O8 plus YSZ with high electrochemical catalytic activity as the sensing electrode, and the purpose of improving the sensing characteristic can be achieved.

In at least one embodiment, a method is described for measuring concentrations of gas moieties in a gas mixture. A mixed-potential gas sensor is exposed to a gas mixture in order to obtain a first and a second mixed-potential gas sensor output responses. The first output response and a second output response are deconvoluted to measure a first analyte gas concentration and a second analyte gas concentration. Some of the output responses may be used as inputs to a control system.

In at least one embodiment, a method is described for measuring concentrations of gas moieties in a gas mixture. A mixed-potential gas sensor is exposed to a gas mixture in order to obtain a first and a second mixed-potential gas sensor output responses. The first output response and a second output response are deconvoluted to measure a first analyte gas concentration and a second analyte gas concentration. Some of the output responses may be used as inputs to a control system.

The invention discloses an all-solid mixed-potential NOx sensor prepared on the basis of spark plasma sintering technology. The NOx sensor consists of an electrolyte layer, a sensing electrode layer, a reference electrode and a working electrode, wherein the multilayer composite consisting of the electrolyte layer and the sensing electrode layer is directly sintered by the spark plasma sintering technology; and the reference electrode layer and the working electrode layer, which have screen pores, are directly printed in the centers of the upper and lower surfaces of the composite by screen printing. As the NOx sensor is manufactured by the spark plasma sintering technology, the sensing electrode layer and the electrolyte layer of the sensor are well combined without problems of flying up, cracking and the like and have the characteristics of good repeatability, stable performance, simple manufacturing process, short manufacturing period, small volume, quick response and the like. The NOx sensor of the invention can detect NOx concentration ranging from 1 to 75 percent and give a response within 2 minutes and is suitable for the detection of the NOx concentration in a wide range.

The invention discloses an indirect methanol fuel cell device based on heteropoly compound energy storage, belonging to the field of new energy resources. In order to solve the problems of overhigh cost of an electrode catalyst of a direct methanol fuel cell, catalyst damage caused by intermediate products, mixed potential generated by methanol permeating in a cathode, reduced performance of the cell, environment pollution, and the like, the invention provides a fuel cell system in which a heteropoly compound stores methanol energy and discharge cycle is carried out on the fuel cell, an intermediate reactor is arranged in a direct methanol fuel cell system, the heteropoly compound is used for oxidizing the methanol under the action of a catalyst in the intermediate reactor, the methanol energy is stored in a reduction-state heteropoly compound in forms of protons and electrons, then the reduction-stage heteropoly compound is separated and then is conveyed to an anode of the fuel cell to be oxidized for recycling, and the recycled heteropoly compound is sent to the intermediate reactor to react with the methanol so as to be recycled. The invention is suitable for power generation of a stationary electric power plant, or other portable and distributed power supply systems.

The invention relates to an YSZ based mixed-potential type acetone sensor taking NiNb206 as a sensitive electrode and a preparation method. The YSZ based mixed-potential type acetone sensor taking NiNb206 as the sensitive electrode is mainly used for detecting atmospheric environment and diabetes mellitus. The sensor comprises a Al2O3 ceramic plate with a Pt heating electrode, a YSZ base plate, a Pt reference electrode and a NiNb206 sensitive electrode in turn, wherein the reference electrode and the sensitive electrode are independent from each other and are symmetrically prepared at the two ends of the upper surface of the YSZ base plate, and the lower surface of the YSZ base plate is adhered to the Al2O3 ceramic plate with the Pt heating electrode. According to the YSZ based mixed-potential type acetone sensor taking NiNb206 as the sensitive electrode, the YSZ is served as an ionic conductive layer, the NiNb206 with high electrochemical catalytic activity is served as the sensitive electrode, and the change in microstructure of the sensitive electrode layer is realized through different calcining temperature (at 800-1200 DEG C), so that the purpose of increasing the sensitivity is achieved.

A sensor for determining a concentration of gas components in gas mixtures having a first measuring electrode (mixed potential electrode) which has little or no catalytic effect on the establishment of an equilibrium in the gas mixture and a second measuring electrode (equilibrium electrode) which catalyzes the establishment of an equilibrium in the gas mixture as well as a solid electrolyte that is conductive for oxygen ions arranged between the two measuring electrodes, with the two measuring electrodes being exposed to the gas mixture. At least the first measuring electrode (16) is a cermet electrode, where at least one metal oxide component of the cermet electrode is capable of reversible incorporation of oxygen.

The invention discloses a YSZ (yttria-stabilized zirconia)-based mixed potential type hydrogen sulfide (H2S) sensor with La2NiO4 used as a sensitive electrode and a method for preparing the YSZ-basedmixed potential type hydrogen sulfide sensor, and belongs to the technical field of gas sensors. The YSZ-based mixed potential type hydrogen sulfide sensor is mainly used for detecting toxic gas H2S in industrial production and daily life. The YSZ-based mixed potential type hydrogen sulfide sensor sequentially comprises an Al2O3 ceramic plate with Pt heating electrodes, a YSZ-based plate, a Pt reference electrode and the La2NiO4 sensitive electrode. The reference electrode and the sensitive electrode are independently and symmetrically prepared at two ends of the upper surface of the YSZ-basedplate, and the lower surface of the YSZ-based plate is adhered with the Al2O3 ceramic plate with the Pt heating electrodes. The YSZ-based mixed potential type hydrogen sulfide sensor and the method have the advantages that the La2NiO4 with high electrochemical catalytic activity is used as the sensitive electrode, the quantities of citric acid and the like which are added in material synthesis procedures are changed, accordingly, the electrochemical catalytic activity of sensitive electrode materials can be enhanced, and effects of improving the sensitivity characteristics of the YSZ-based mixed potential type hydrogen sulfide sensor can be realized; a short temperature pulse is applied in sensor recovery procedure, accordingly, the recovery time of the YSZ-based mixed potential type hydrogen sulfide sensor can be shortened, and the purpose of enhancing the response and recovery characteristics of the YSZ-based mixed potential type hydrogen sulfide sensor can be achieved.

A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

In a gas sensor determining a NOx concentration in a measurement gas based on a pump current flowing between a NOx measurement electrode and an outer pump electrode, the outer pump electrode has catalytic activity inactivated for HC and CO, so that a sensor element further includes a HC sensor part having a mixed potential cell constituted by the outer pump electrode, a reference electrode, and a solid electrolyte between these electrodes, and a HC mode for determining a HC concentration in the measurement gas based on a potential difference between the outer pump electrode and the reference electrode when the sensor element is heated to a temperature which is 400° C. or higher and 650° C. or lower and a NOx mode for determining a NOx concentration in the measurement gas based on the pump current can selectively be performed based on the temperature of the sensor element.

A mixed potential sensor device and methods for measuring total ammonia (NH3) concentration in a gas is provided. The gas is first partitioned into two streams directed into two sensing chambers. Each gas stream is conditioned by a specific catalyst system. In one chamber, in some instances at a temperature of at least about 600° C., the gas is treated such that almost all of the ammonia is converted to NOx, and a steady state equilibrium concentration of NO to NO2 is established. In the second chamber, the gas is treated with a catalyst at a lower temperature, preferably less than 450° C. such that most of the ammonia is converted to nitrogen (N2) and steam (H2O). Each gas is passed over a sensing electrode in a mixed potential sensor system that is sensitive to NOx. The difference in the readings of the two gas sensors can provide a measurement of total NH3 concentration in the exhaust gas. The catalyst system also functions to oxidize any unburned hydrocarbons such as CH4, CO, etc., in the gas, and to remove partial contaminants such as SO2.

The invention discloses a method for vulcanizing and separating valuable metal in a solution through controlled potential. The method comprises the steps that 1, alkali and sulfate are simultaneously added into the copper-cobalt-manganese solution to remove calcium in the solution; 2, sodium sulphide is added into the calcium removed solution to enable the mixed potential of metal ions in the solution to be controlled to be a required value, and meanwhile hydrochloric acid is added to adjust the pH value of the solution; 3, after the solution potential is stabilized and continuously stirred, filtering and copper removing are conducted; 4, after coppering removing is completed, the sodium sulphide is added to enable the mixed potential of the metal ions in the solution to be controlled to be the required value, and the hydrochloric acid is added to adjust the pH value; 5, after the solution potential is stabilized and continuously stirred, filtering is conducted; and 6, the pH value of the cobalt removed solution is neutralized through the alkali to reach a required value, the solution is filtered after being stirred, deposited manganese slag is obtained, and selective step-by-step separation of the valuable metal in the solution is achieved. According to the method for vulcanizing and separating the valuable metal in the solution through the controlled potential, selective separation of the valuable metal in the solution is achieved by controlling the mixed potential of the metal ions in the solution and the pH value at the same time; selective separation of the valuable metal in the solution is achieved, and the deposition rate of copper, the deposition rate of cobalt and the deposition rate of manganese are all 99.0% or above.

The invention relates to a large signal stability analysis method for an AC microgrid system considering the dynamic performance of an energy storage system and constant power load. The circuit topology of the AC microgrid is shown in Figure 1. When the energy storage system is in a charging mode, the stability criterion in the charging mode of the storage system can be obtained as follows: C / L1>Pb / V2<2>R1; and when the energy storage system works in a discharging mode, the stability criterion of the energy storage in the charging mode can be obtained as follows: C2 / L1>P2 / V3<2>R1. The AC microgrid is converted into a DC system under a dq rotating coordinate system. The large signal stability criterion is proposed by using a mixed potential function theory. The stability criterion is derived based on the AC microgrid mixed potential function model converted into the DC system. The criterion takes the dynamic performance of the constant power load and the energy storage system into consideration at the same time, gives quantitative constraints on the design of system parameters, ensures the stability of the system under the large disturbance condition and verifies the effectiveness by simulation.

The invention discloses a method and system for rounting a potential energy field supporting real-time transmission in a wireless sensor network. The method comprises the following steps: S1. caching data packets sent due to the requests of an application program; S2. analyzing header identifications of the data packets; if the data packets are real-time data packets, transmitting the data packets by using a deep potential energy field, otherwise, transmitting the data packets to a link layer for processing through a mixed potential energy field. By utilizing the method and the system, the minimized end-to-end transmission delay can be provided for real-time traffic of the wireless sensor network, and the jamming which may occur in the network can be alleviated simultaneously, thus the throughput capacity of the network is improved.

The invention belongs to a routing method capable of realizing the balanced energy consumption by virtue of a mixed potential energy field in the technical field of wireless sensor networks. The routing method comprises the steps of initializing a network, sending a sink node depth value, updating and sending a first skip node depth value, updating a routing list, determining current parameter information of each node in a second skip, determining and updating residual energy of each node, determining and updating an energy density value of each node, processing data packets generated and received by the nodes, determining candidate nodes a next skip, determining a mixed potential energy field value of each candidate node in the next skip, and determining a first-choice node in the next skip and a next skip node. According to the method, the candidate nodes of the next skip nodes are screened out firstly, and then the first-choice node and the skip jump node are screened out from the candidate nodes. The routing method has the characteristics that the network load is uniform, the energy consumption of each node is balanced, a untimely blind zone of the network is avoided, the service life of energy sources is prolonged, the network operation reliability is improved effectively, benefits are increased effectively, the network operation cost is reduced, and the like.

Provided is a method of suitably judging necessity of a recovering process carried out on a mixed-potential gas sensor based on an extent of reversible deterioration occurring in a sensing electrode. The method includes the steps of: (a) performing impedance measurement between a sensing electrode exposed to a measurement gas and a reference electrode exposed to a reference atmosphere, which are provided in the gas sensor; and (b) judging necessity of a recovering process based on electrode reaction resistance or a diagnosis parameter correlating with the electrode reaction resistance wherein the electrode reaction resistance and the diagnosis parameter are obtained based on a result of the impedance measurement. The two steps are intermittently or periodically repeated during use of the gas sensor, and it is judged that a recovering process is necessary when the judge parameter satisfies a predetermined threshold condition in the step (b).

Disclosed is a bipolar membrane type direct borohydride fuel cell. The bipolar membrane type direct borohydride fuel cell comprises at least one cell unit; each cell unit consists of two layers of solid-state electrolyte membranes with ion selectivity transmission property; the solid-state electrolyte membranes are divided into two parts by the bipolar membrane; and the bipolar membrane adopts a three-layer structure which includes a cation exchange membrane layer, an anion exchange membrane layer and an intermediate interface layer positioned between the two exchange membrane layers. By adoption of the bipolar membrane type direct borohydride fuel cell, the negative electrode and the positive electrode can adopt non-uniform electrolytes, and a mixed potential caused by permeation of an intermediate product generated by the positive electrode fuel or the positive electrode to the negative electrode can be prevented; and meanwhile, permeation of a negative electrode product to the positive electrode also can be prevented, polarization loss of the electrode is lowered, the mixed potential is eliminated, and the fuel utilization rate and the output power are improved.

A mixed potential electrochemical sensor for the detection of gases has a ceria-based electrolyte with a surface for exposing to the gases to be detected, and with a reference wire electrode and a sensing wire electrode extending through the surface and fixed within the electrolyte as the electrolyte is compressed and sintered. The electrochemical sensor is formed by placing a wire reference electrode and a wire sensing electrode in a die, where each electrode has a first compressed planar section and a second section depending from the first section with the second section of each electrode extending axially within the die. The die is filled with an oxide-electrolyte powder and the powder is pressed within the die with the wire electrodes. The wire-electrodes and the pressed oxide-electrolyte powder are sintered to form a ceramic electrolyte base with a reference wire electrode and a sensing wire electrode depending therefrom.

A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

The invention provides a method for selectively precipitating and separating cobalt in a potential-control manner. Copper-cobalt-manganese slag is used for neutralizing a copper-cobalt-manganese solution to a required pH value; then, sodium sulphide is added under the condition of simultaneously controlling the solution potential and the pH value to perform vulcanization copper removal; after the copper removal, sodium ethylxanthate is added under the condition of simultaneously controlling the solution potential and the pH value to perform precipitation cobalt removal; after the cobalt removal, sodium sulphide is added into the solution under the condition of simultaneously controlling the solution potential and the pH value to perform vulcanization zinc removal; after the zinc removal, sodium carbonate is added in the solution for neutralizing and producing manganese carbonate. The method practically realizes the stepped precipitation and separation of the copper, the cobalt and the zinc in the solution through simultaneously controlling the metal ion mixed potential and the pH value in the solution; particularly, the cobalt content in the cobalt precipitate products reaches more than 20.0 percent; the processes are closely associated; the single process cannot reach the expected effect of the stepped separation of valuable metal.

The invention belongs to the technical field of gas sensors and in particular relates to a mixed potential NO2 gas sensor which is produced by taking a PS microsphere as a template, immersing with a solution containing zirconium and yttrium ions and sintering to prepare a nano bowl-shaped array structure on the surface of a YSZ base plate, and taking the YSZ base plate as a base plate. The sensor provided by the invention is mainly used for detecting automobile exhaust. The mixed potential NO2 gas sensor is composed of an Al2O3 ceramic plate with a Pt heating electrode, the YSZ base plate, a Pt reference electrode and a sensitive electrode in sequence; the upper surface of the YSZ base plate is the nano bowl-shaped array structure composed of yttrium-stabilized zirconia. According to the mixed potential NO2 gas sensor provided by the invention, the YSZ base plate with the nano bowl-shaped array structure constructed is prepared by a PS microsphere template method and is used as electrolyte; the contact of gas to be detected and the electrolyte is improved by the nano bowl-shaped array structure on the surface so that reaction active sites are increased and the aim of improving the sensitivity of the sensor is realized; furthermore, the nano bowl-shaped array structure has hydrophobic characteristics, so that the moisture resistance of the sensor is greatly improved. The mixed potential NO2 gas sensor is shown as a figure 1.

The invention relates to a power electronic power system transient stability analysis method based on a direct method. The method comprises the following steps: 1, determining a system model, 2, constructing a Lyapunov energy function: firstly, establishing a mixed potential function P (i, v) according to a reasonably simplified and determined system model, and secondly, constructing a Lyapunov type energy function of the system in combination with a stability discrimination theorem in a mixed potential function theory, and solving a differential value of the Lyapunov type energy function, andfinally, judging the transient stability of the system through the characteristics of the energy function and the differential value thereof, and 3, estimating the critical energy of the system.

The invention discloses a DC micro-grid steady-state performance analysis method based on an energy storage system. The method comprises the following steps: respectively establishing a mixed-potential function model under a charging mode and a mixed-potential function model under a discharging model in a DC micro-grid system based on the characteristics of the DC micro-grid system in isolated island operation; respectively performing steady-state performance analysis based on the constructed mixed-potential function model and the stability theorem to obtain the stability conditions of the energy system under the charging mode and the discharging mode; regulating the parameter setting of the energy storage system according to the obtained stability conditions, and the controlling the stable operation of the DC micro-grid system. The DC micro-grid steady-state performance analysis method based on the energy storage system not only can conveniently and practically realize the elimination of the negative impedance characteristic of the constant power load, but also cannot cause the extra cost; and the realization is easy.