195 results about "Ac circuit" patented technology

The invention discloses an energy storage type SOP black-start method, system and device based on improved VSG network construction control and a medium, and relates to the field of power grid black-start, and the method comprises the steps: an energy storage type converter MMC carries out the active and reactive control based on an improved VSG network construction control strategy; a non-fault side MMC is controlled to firstly close an isolation circuit breaker and slowly charge a direct-current capacitor, and when the voltage reaches a set threshold value, a current-limiting resistor is quitted; the fault side MMC is started by the same step as the non-fault side MMC; after synchronization is completed, AC circuit breakers between the non-fault side MMC and the feeder load and between the fault side MMC and the feeder load are closed respectively; based on the collected power grid power data, MMC output parameters are adjusted to meet the power grid connection condition, the control mode is switched according to the grid connection state, and the black start process is ended. And by arranging the black start resistor for current-limiting charging and sub-module voltage balance control, the phenomena of overcurrent and voltage unbalance in the black start process are avoided.

The invention relates to the technical field of energy storage, and discloses a synchronous test platform for multiple energy storage converters and a control method of the synchronous test platform. The test platform comprises a wire inlet switch, a pre-charging loop, a transformer, an auxiliary power supply switch, an alternating-current circuit breaker, a direct-current circuit breaker and a unit controller, a power grid is connected to the high-voltage side of the transformer through the wire inlet switch and the pre-charging loop in sequence, and one side of the alternating-current circuit breaker is connected with a winding on the low-voltage side of the transformer. The direct current side of the first group of energy storage converters is connected with the direct current side of the second group of energy storage converters through the direct current circuit breaker, and the first group of energy storage converters is connected with the auxiliary power supply. According to the test platform, the pre-charging loop is bypassed after the first group of PCS is pre-charged, then the first group of PCS unlocks the direct current voltage control mode, and the second group of PCS starts in sequence control, so that the synchronous charging and discharging test of 2N PCSs is realized, and the charging and discharging test efficiency of the energy storage converter is greatly improved.

The invention discloses a hybrid multi-level battery energy storage system of a three-port converter. The hybrid multi-level battery energy storage system comprises a direct current port, an alternating current port, a battery port, a choke inductor, a power frequency module, a filtering module, a controller and a plurality of switch modules, the switch modules are divided into two groups, and the two groups of switch modules and a plurality of switch modules in the switch modules form cascade connection and are correspondingly connected with the direct current ports; the choke inductor is arranged between the two groups of switch modules and is correspondingly connected with the filtering module; the power frequency module is connected with the DC port and the filtering module. The power frequency module comprises a commutation circuit formed by two power switch tubes; the controller is electrically connected with the power frequency module and each switch module. When the hybrid energy storage device is connected to photovoltaic and wind power new energy direct current ports, a new energy DC / AC circuit does not need to be additionally arranged, the size of the energy storage device is reduced, and the cost of the hybrid energy storage system is reduced.

The utility model provides an electric energy meter calibrating device comprising a calibrating box body, the calibrating box body comprises a first plate and a second plate which are arranged at intervals along a first direction, and at least one of the first plate and the second plate is provided with at least one first air port; the second air opening is formed in the plate body for connecting the first plate and the second plate; the supporting partition plate is arranged in the verification box body in the first direction, and the space in the verification box body is divided into a first cavity and a second cavity by the supporting partition plate; the plurality of direct-current circuit boards are connected with the supporting partition plate, the direct-current circuit boards are arranged in the first cavity, and at least one direct-current circuit board is provided with a first heating piece; the at least one first fan is arranged on the supporting partition plate, and the first fan and the first heating piece are oppositely arranged; and the plurality of alternating-current circuit boards are connected with the supporting partition plate and are arranged in the second cavity. According to the technical scheme, the direct current circuit board and the alternating current circuit board are arranged in a layered mode, the heat dissipation capacity of the device is remarkably improved, and the temperature of the whole system is kept stable.

The present invention provides a method and system for detecting the switching state of the closing resistor of an AC filter group circuit breaker, which belongs to the technical field of high-voltage AC circuit breakers. The method comprises: loading the closing current recording data of the filter group circuit breaker switching process; performing wavelet decomposition on the closing current recording data of the circuit breaker, obtaining the singular points in the closing current recording data of each layer of the circuit breaker as the starting points of each transient process during the closing resistor switching process of the circuit breaker; performing TLS-ESPRIT decomposition on the recording data of each transient process to obtain the amplitude and attenuation factor of the DC mode, and establishing a corresponding relationship between the amplitude, attenuation factor and the actual resistance value of the closing resistor; fitting two amplitude-resistance curves and two attenuation factor-resistance curves according to the corresponding relationship, as well as the curve function and inverse function of each curve; substituting the amplitude and attenuation factor into the inverse function of the corresponding DC component to calculate the resistance value, and further calculating the number of flashover resistors based on the average resistance value, so as to understand whether a flashover fault occurs.

This invention relates to the field of energy storage technology and discloses a synchronous testing platform for multiple energy storage converters and its control method. The testing platform of this invention includes: an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller. The power grid is connected to the high-voltage side of the transformer sequentially through the incoming line switch and the pre-charge circuit. One side of the AC circuit breaker is connected to the windings on the low-voltage side of the transformer, and the other side is connected to the AC side of the energy storage converter. The DC side of the first group of energy storage converters is connected to the DC side of the second group of energy storage converters through DC circuit breakers. The first group of energy storage converters is connected to the auxiliary power supply. In this invention, after the first group of PCS (Power Storage Converters) is pre-charged, the pre-charge circuit is bypassed. Then, the first group of PCS is unlocked and controlled in DC voltage mode, and the second group of PCS is started sequentially, thereby achieving synchronous charging and discharging testing of 2N PCS, greatly improving the charging and discharging testing efficiency of the energy storage converter.

Disclosed in the present invention is a high-voltage high-frequency SiC Mosfet novel power transformer, comprising a superordinate computer, a controller, an inverter circuit, and a signal detection circuit. The superordinate computer is connected to the controller; the inverter circuit uses a three-phase T-type inverter topology circuit to convert high-voltage power in a three-phase circuit into three-phase controllable AC power; the inverter circuit comprises a primary rectifier circuit, a primary DC-AC circuit, a three-phase winding transformer, a secondary rectifier circuit, and a secondary DC-AC circuit; a plurality of SiC Mosfets are used in the primary rectifier circuit, the primary DC-AC circuit, the secondary rectifier circuit, and the secondary DC-AC circuit; the signal detection circuit obtains detection data; and a DSP is provided in the controller, the DSP is provided with an algorithm module, the algorithm module performs an operation on the basis of the detection data to generate a specific instruction, and the controller adjusts the inverter circuit on the basis of operating parameters or the specific instruction. In the present invention, a plurality of SiC Mosfets are used, and the structure of the inverter circuit is optimized, thereby improving the working efficiency; and a detection and control feedback mechanism is additionally provided, so that effective regulation within the transformer can be realized, thereby improving the performance.

The invention discloses a voltage circuit breaker AC open circuit control method and device, and relates to the technical field of open circuit control, and the method comprises the following steps: obtaining a target waveform sequence of a target AC circuit, and obtaining a fundamental component and a higher harmonic component through frequency domain decomposition, so as to extract current waveform features; constructing a zero-crossing prediction model based on current waveform characteristics, dynamically correcting the prediction model in combination with higher harmonic components and load asymmetry characteristics, and generating a preliminary breaking moment candidate interval; determining a final on-off moment by combining the instantaneous power direction reversal point and an arc maintenance energy threshold value; and triggering the circuit breaker to act at the final breaking moment, and dynamically adjusting the contact separation speed based on the residual arc energy until the arc energy is attenuated to a safety value. According to the method, the zero-crossing prediction model is constructed by extracting the current waveform characteristics, the contact separation strategy is dynamically corrected, and the problems of arc extension and equipment damage of a traditional circuit breaker under the condition of harmonic distortion or sudden disturbance are solved.

A thermal impedance monitoring process for a power module of a power converter for converting a DC current to an AC current, or converting an AC circuit to a DC current, where a semiconductor dissipates asymmetric losses between two half cycles of an AC frequency f of the AC current, said power module comprising at least a semiconductor die, a semiconductor die is attached to a stack of materials of layers for heat dissipation and / or electrical connection thereof, the process comprising: sampling and measuring a signal related to a junction temperature Tj of the semiconductor die at a frequency higher than twice the AC frequency of the AC current, calculating a duration [Delta] t = tTjmax-tTjmin between a moment tTjmax at which the junction temperature of the semiconductor die is at a maximum value and a moment tTjmin at which the junction temperature is at a minimum value in one cycle of the AC current, and storing the duration [Delta] t in a memory, repeating the step of sampling and measuring said signal and the step of calculating said duration at different times tx = t0 to tm during the operating life of the power module to provide a series of durations [Delta] t0 to [Delta] tm, and comparing the values of said durations [Delta] t0 to [Delta] tm for monitoring the evolution of said duration [Delta] t, and determining the evolution of the degradation of the thermal impedance of the power module.

The present invention provides a single-stage high-frequency isolated DC / AC inverter, comprising a primary-side bridge inverter circuit, a high-frequency transformer, a series resonant cavity and a secondary-side AC circuit which are connected in sequence. The inverter is modulated by a control circuit, and an inverter modulation method is set in the control circuit and comprises the steps of: determining an inner phase shift angle between primary-side bridge arms, an outer phase shift angle between each primary-side bridge arm and a secondary-side bridge arm, and switching frequencies of a primary-side switching transistor and a secondary-side switching transistor on the basis of a fundamental harmonic approximation algorithm, so as to modulate control variables of the inverter, wherein the control variables include a power transmission characteristic and a soft switching characteristic; and calculating precise current values at switching instants of the primary-side switching transistor to compensate the control variables on the basis of the precise current values.

The invention relates to the technical field of vehicle charging sockets, in particular to a charging socket signal switching mode. According to the charging socket signal switching mode, a socket shell is included, an inner cavity of the socket shell is divided into a DC cavity and an AC cavity, a DC circuit board and an AC circuit board are connected with SMD thermistors respectively so as to measure the temperature of DC and AC power terminals, the DC circuit board and the AC circuit board are connected with multi-PIN connectors respectively, and multi-PIN contact pins are integrated in the socket shell. The two ends of the multi-PIN pin extend into the DC cavity and the AC cavity respectively and are connected with the multi-PIN connector of the DC circuit board and the multi-PIN connector of the AC circuit board in an inserted mode, so that a DC power terminal temperature signal is transmitted to the AC circuit board through the multi-PIN connector of the DC circuit board, the multi-PIN pin and the multi-PIN connector of the AC circuit board in sequence and led out through the low-voltage connector of the AC circuit board. Through a signal switching mode of integrating the PINs in the socket shell, the split type design of the AC cavity and the DC cavity can be realized, so that the assembling performance and the sealing reliability of the product are improved.

An electric propulsion system for an aircraft, comprising: - an electrical power source (1) including a synchronous generator (11) driven by a heat engine (12), - a first synchronous electric motor (3) connected to an output of the synchronous generator by an alternating current electrical circuit (2), - a rotating propulsion unit (7), characterized in that it comprises: - a direct current electrical circuit (4) comprising, from an input connected to the alternating current electrical circuit: a first alternating / direct current converter (41), a direct current electrical link (42) and a second direct / alternating converter (43), - a second electric motor (5) connected to an output of the direct / alternating converter, - a differential gear train (6) including a first input shaft (61) connected to the first synchronous electric motor,a second input shaft (62) connected to the second electric motor and an output shaft (63) connected to the rotating propulsion unit. Figure for the abbreviation: Figure 1,

The utility model provides an electric power system relay protection tripping matrix rapid detection device comprising a box body, and a control circuit is integrated in the box body; the control circuit comprises a first alternating current air switch, the other end of the first alternating current air switch is connected with one end of a second alternating current air switch, and the other end of the second alternating current air switch is connected with a relay control loop; the relay control loop comprises a knob switch and a static intermediate relay; the knob switch is connected in series with a coil contact in the static intermediate relay; a signal indication loop is connected between the first alternating current air switch and the second alternating current air switch; the signal indication loop comprises a plurality of signal lamps which are connected in series with a normally open contact in the static intermediate relay; two sides of each group of normally open contacts in the static intermediate relay are connected in parallel with a group of plug protection loops. The device can directly judge whether the tripping contact is switched on or not by observing the state of the signal lamp, so that the state of the tripping outlet contact is judged, the test time is greatly saved, and the labor intensity of verification personnel is reduced.

A DC:DC converter includes: a DC:AC converter circuit having DC and AC sides; an AC:DC converter circuit having DC and sides; an AC link connecting the AC side of the DC:AC circuit and the AC side of the AC:DC converter circuit, the AC link including a transformer having a first winding connected to the AC side of the DC:AC converter circuit and a second winding connected to the AC side of the AC:DC converter; a capacitor; and a switch arrangement having a first state and a second state, wherein: in the first state, the capacitor is connected in series between the AC side of the DC:AC converter circuit and the first winding of the transformer; and in the second state, there is a current path between the AC side of the DC:AC converter circuit and the first winding of the transformer that does not include the capacitor.

The utility model provides a dual-power low-voltage power distribution system. The dual-power-supply low-voltage power distribution system comprises a main power supply and a standby power supply, and the standby power supply comprises a controller, a battery, a DC-DC circuit, a DC-AC circuit and a main power supply voltage detection module. The main power supply voltage detection module comprises a main power supply voltage acquisition circuit, a first rectifier bridge, a first subtraction circuit, a first absolute value detection circuit, a first comparator and a second comparator which are connected in sequence, and the main power supply voltage acquisition circuit is used for acquiring main power supply voltage in real time; the first input end of the first subtraction circuit is connected with the output end of the first rectifier bridge, the second end of the first subtraction circuit is connected with the first reference voltage, and the output end of the first subtraction circuit is connected to the input end of the first absolute value detection circuit. The problem of long switching time between the main power supply and the standby power supply in the existing dual-power-supply low-voltage power distribution system can be solved.

This invention discloses an AC circuit breaker control method and device, relating to the field of circuit breaker control technology. The method includes the following steps: acquiring the target waveform sequence of the target AC circuit and obtaining the fundamental and higher harmonic components through frequency domain decomposition to extract current waveform features; constructing a zero-crossing prediction model based on the current waveform features, and dynamically correcting the prediction model by combining the higher harmonic components and load asymmetry characteristics to generate a candidate interval for the initial breaking time; determining the final breaking time by combining the instantaneous power direction reversal point and the arc sustaining energy threshold; triggering the circuit breaker operation at the final breaking time, and dynamically adjusting the contact separation speed based on the residual arc energy until the arc energy decays to a safe value. This invention solves the problems of arc extension and equipment damage in traditional circuit breakers under harmonic distortion or sudden disturbances by extracting current waveform features to construct a zero-crossing prediction model and dynamically correcting the contact separation strategy.

The invention discloses an electric power protection system, a control method and a related product. The power protection system comprises a controller, a switch assembly and a three-phase shunt reactor, the three first ends of the switch assembly are connected with the three-phase alternating current circuits in a one-to-one correspondence mode, the three second ends of the switch assembly are connected with the first ends of the three-phase shunt reactors in a one-to-one correspondence mode, and the second ends of the three-phase shunt reactors are connected together. A controller configured to obtain a three-phase AC voltage and a three-phase AC current; obtaining three-phase interphase impedance according to the three-phase alternating voltage and the three-phase alternating current; according to the three-phase interphase impedance, judging whether the reactor has a turn-to-turn short circuit fault or not; and under the condition that the reactor has a turn-to-turn short circuit fault, the switch assembly is controlled to be switched off. According to the embodiment of the invention, whether the reactor has the turn-to-turn short circuit fault or not is judged through the three-phase interphase impedance, and the switch assembly is controlled to be switched off under the condition that the reactor has the turn-to-turn short circuit fault, so that the safety of a power grid is improved.

The invention relates to the technical field of signal switching, in particular to a signal switching structure, and solves the problems that in the prior art, a signal switching and assembling structure of an AC / DC circuit board is complex in assembling process, and assembling consistency is difficult to guarantee. The AC power terminal and the DC power terminal are installed in the socket shell, the low-voltage connector is used for collecting and leading out temperature signals, a DC cavity and an AC cavity are formed in the socket shell, the side edges of the DC cavity and the side edges of the AC cavity are communicated, and a circuit board assembly is arranged in the socket shell; the circuit board assembly comprises an AC circuit board installed in the AC cavity and a DC circuit board installed in the DC cavity, and the AC circuit board and the DC circuit board are electrically interconnected and mechanically fixed through a plug-in. The integrated circuit board assembly has the advantages that the AC circuit board and the DC circuit board are connected and fixed in advance through the plug-in to form the integrated circuit board assembly, synchronous assembly of the AC circuit board and the DC circuit board is achieved through the integrated structure, the assembly process is simplified, and deviation accumulation caused by step-by-step assembly is avoided.

The invention discloses a power converter, a charging control method, an optical storage and charging system and a storage medium. The power converter comprises a direct current bus arranged on the direct current side of the power converter; the slow start circuit is arranged on the alternating current side of the power converter, and the on-off state of the slow start circuit is used for controlling on-off between the alternating current side and the alternating current circuit; the controller is used for executing the following operations: controlling the slow start circuit to be conducted, so that the direct-current bus receives the electric energy of the alternating-current circuit; boosting the voltage on the DC bus to a target voltage according to the electric energy of the AC circuit; and providing power for the charging module by using the direct-current bus with the boosted voltage, so that the charging module charges the to-be-charged equipment. The power converter can ensure that the optical storage and charging system can work continuously, further ensure that the optical storage and charging system can charge the to-be-charged equipment at any time, and improve the user experience.

The utility model provides an energy storage power station heterogeneous energy storage unit collaborative operation simulation system, which is used for simulating collaborative grid connection of various energy storage units, and comprises a first energy storage unit, a second energy storage unit, a third energy storage unit, a fourth energy storage unit and a fourth energy storage unit, wherein the first energy storage unit is composed of a battery cluster, a first bidirectional DC / AC circuit and a three-phase boosting transformer which are sequentially connected in series; the second energy storage unit is composed of a battery cluster, a second bidirectional DC / AC circuit and a single-phase boosting transformer which are sequentially connected in series; the third energy storage unit is composed of a battery cluster, a bidirectional DC / DC conversion circuit and a first bidirectional DC / AC circuit which are sequentially connected in series; the sampling units are connected with the battery clusters of the energy storage units, and are used for acquiring single cell voltage, inter-cluster current and grid-connected voltage of the energy storage units and transmitting the voltage, the current and the grid-connected voltage to an upper computer; and a user can master the working state of each heterogeneous energy storage unit and the state of the single battery cell in real time.

A circuit breaker device protects an electric multi-phase low-voltage alternating current circuit. The device contains a housing having grid-side phase connections and load-side phase connections for phase conductors of the low-voltage alternating current circuit. Series circuits of the device each contain a mechanical phase contact and an electronic switch. Each series circuit electrically connects a grid-side phase connection to one of the load-side phase connections. The mechanical phase contacts are switched together to an open state to prevent a current flow or to a closed state for a current flow, by use of semiconductor-based switch elements. In each series circuit, the level of the current of the respective phase conductor is ascertained. If a first current threshold or current / time threshold is exceeded in a phase conductor, a prevention of the current flow is initiated, and the electronic switches are switched to a high-ohmic or low-ohmic state by a control input.

The application discloses a kind of based on heat dissipation optimization intelligent self-sensing carbon fiber and metal composite structure design method, comprising: determining the size of carbon fiber and metal composite structure, heat source position and carbon fiber thermal characteristics;Determine the thickness of step, calculate the length of step using Fourier's law;Carbon fiber both ends smears conductive silver glue and heats solidification;After solidification is completed, carbon fiber and metal composite structure are connected into alternating current circuit, record current and calculate resistance;Using variational mode decomposition, alternating current is decomposed;Using energy entropy algorithm and spectral energy algorithm, the calculation is carried out to the decomposition result, according to the resistance value and the change of energy entropy and spectral energy obtained by calculation, realize carbon fiber / metal composite structure self-sensing.The application designs step structure and realizes optimized heat dissipation, which can reduce the thermal deformation and carrying capacity of carbon fiber / metal composite structure, and at the same time, through current acquisition and measurement, analysis, realize the intelligent self-sensing of composite structure.

The invention provides an electromagnetic brake control device which further controls an electromagnetic brake without delay. An electromagnetic brake control device (55), which controls an electromagnetic brake (54) that brakes the rotation of an AC motor (53) when the energization of an electromagnetic brake coil (54a) is cut off, is provided with: a rectifier (81), the DC side of which is connected to the electromagnetic brake coil (54a); a switching unit (84) that controls the power to the electromagnetic brake coil (54a) by switching a rectifier circuit (RL) connecting the rectifier (81) and the electromagnetic brake coil (54a) on and off; a DC converter (82) that is connected to the motor drive AC circuit (51a) and converts AC power to a predetermined DC voltage; an electromagnetic brake release circuit unit (85) that switches the switching unit (84) to an ON state by means of the DC voltage generated by the DC converter (82); and an electromagnetic brake operation command unit (83) that switches the switching unit (84) to the OFF state when the value of the current waveform of the AC motor (53) is between a positive threshold value and a negative threshold value and lasts for a predetermined determination time or longer.

The invention discloses a distributed relay protection secondary alternating current loop abnormity diagnosis method, and relates to the technical field of power system relay protection, edge diagnosis nodes with a self-organizing network function are deployed at key nodes of a secondary alternating current loop of a distributed relay protection system, and a distributed diagnosis network is formed; the edge diagnosis node collects multi-dimensional feature data of the secondary alternating current loop in real time through a multi-mode sensing unit, wherein the multi-dimensional feature data comprises electrical quantity features, waveform distortion features, time sequence features, environment features and the like; according to the method, distributed edge diagnosis nodes are deployed, multi-dimensional feature data of a secondary alternating-current loop are collected, the multi-dimensional feature data are preprocessed by the edge nodes and then uploaded to a block chain network for consensus verification, and abnormal accurate positioning and grading are achieved in combination with an improved deep learning model; the method effectively solves the problems that a traditional centralized diagnosis method is poor in real-time performance, weak in anti-interference capability and low in data credibility.

An integrated power supply device is provided in which AC sides of three or more DC / AC circuits are coupled by a transformer with three or more windings. The integrated power supply device is capable of correctly outputting power in all assumed drive modes (current directions) and reducing loss without adding a discharge device. In the integrated power supply device in which AC sides of three or more DC / AC circuits are coupled by a transformer with three or more windings, the three or more DC / AC circuits include a first DC / AC circuit including a first switching circuit and a capacitor connected in parallel with the first switching circuit, and a second DC / AC circuit including a second switching circuit connected to a power storage unit.When power is supplied from the second DC / AC circuit to a load connected to a DC / AC circuit other than the first DC / AC circuit, and the first switching circuit is unloaded or a connected load is equal to or less than a predetermined power consumption value, the first switching circuit is switched to provide a period for supplying power from the capacitor to the first switching circuit along with the switching of the second switching circuit.

The invention discloses an overvoltage suppression system and method for PVL-HVDC parallel operation power transmission, and belongs to the technical field of power transmission. The system comprises a power transmission end AC circuit, an LCC-HVDC subsystem, a VSC-HVDC subsystem and an NOSS control circuit. The LCC-HVDC subsystem and the VSC-HVDC subsystem are jointly connected with a power transmission end alternating current circuit, the LCC-HVDC subsystem and the VSC-HVDC subsystem are connected through a connecting line, and the NOSS control circuit is connected with a converter control circuit of the VSC-HVDC subsystem. According to the technical scheme, the NOSS control circuit of the VSC-HVDC subsystem is utilized, the sensitivity of the VSC-HVDC side voltage to the reactive power change is calculated through the improved Jacobian matrix, the sensitivity is used as a control coefficient to be integrated into a VSC-HVDC rectifier control loop, the reactive power regulation capability of the VSC-HVDC is optimized, the VSC-HVDC side overvoltage condition is automatically and rapidly responded, and the VSC-HVDC side voltage reactive power regulation method is suitable for the VSC-HVDC rectifier control loop. The problem of AC bus overvoltage caused by surplus reactive power due to commutation failure of the LCC-HVDC side in the PVL-HVDC parallel system is solved.

The present invention improves the performance of a power module. In particular, the generation of discharge is prevented within the power module, and the power module is miniaturized. As a means for this, a plurality of substrates are arranged within the power module so as to overlap when viewed from above. In this case, a low-voltage circuit (3) and a high-voltage circuit are formed on a first substrate (2) while maintaining a distance (L) between each other for preventing creeping discharge, and a low-voltage circuit (5) is formed on a second substrate (4). In addition, the distance between the components constituting the high-voltage AC circuit (8) formed in the high-voltage circuit and the components constituting the low-voltage circuit (5) is at least three times the shortest distance (D) between the components constituting the high-voltage DC circuit (7) formed in the high-voltage circuit and the components constituting the low-voltage circuit (5) at which no space discharge occurs.

The invention discloses an anti-surge ceramic capacitor material and a preparation method thereof, and belongs to the technical field of electronic ceramic materials. The material is prepared by taking high-purity barium titanate (BaTiO3) as a basic raw material and cooperatively doping lanthanide oxide (La2O3) and transition metal carbonate (MnCO3) as a grain boundary regulating agent through a solid phase method. The ceramic capacitor material is prepared from the following components in mol percent: 96 to 98 mol percent of BaTiO3, 1 to 2.5 mol percent of La2O3 and 0.5 to 2 mol percent of MnCO3, and the sum of the mol percent of all the components is 100 percent. According to the invention, La < 3 + > and Mn < 2 + > are synergistically segregated on a grain boundary, so that a compact grain boundary layer is formed, grains are refined, defects are inhibited, and the surge breakdown resistance (greater than or equal to 10 kV / mm) is remarkably improved. The material has a wide application prospect in surge frequency scenes such as an alternating current circuit and a power supply module.

The invention relates to the technical field of electric power, in particular to an outdoor high-voltage alternating-current circuit breaker which comprises a box body, a supporting plate is arranged on the side, away from the box body, of a current transformer, a column rod is rotationally connected to the middle of the upper surface of the supporting plate, three hemispherical wind shields are annularly installed at the upper end of the column rod at equal intervals, and a cam is installed on the column rod; the two sets of pushing plates are slidably installed on the upper surface of the box body, cylinders are installed at the two ends of the connecting plate and sleeved with cylinders, connecting rods are installed at the ends, close to the box body, of the cylinders, and the ends, away from the cylinders, of the connecting rods penetrate through the cylinders and are connected with the pushing plates. The bird nesting prevention device has the following beneficial effects that the nesting action of birds is destroyed, and the birds are prevented from nesting between the pole columns in the aspect of behavior.