14 results about "Fault current limiter" patented technology

The invention discloses a planning method of a wind power AC / DC power transmission network under short-circuit current constraint in the technical field of electrical information. The method comprises the following steps: constructing a short-circuit current calculation model comprising wind power plant feed-in, an AC power transmission line, a traditional DC power transmission line and a fault current limiter; according to the method, wind power plant feed-in short-circuit currents of different forming mechanisms are calculated through the established short-circuit current calculation model, a unified node short-circuit current function is formed, the short-circuit currents of various forming mechanisms are described in a unified mode, constraint conditions for solving the alternating-current and direct-current power transmission network stochastic programming model are formed, and the method has the advantages of being simple in structure and convenient to operate. And the stochastic programming model of the AC / DC power transmission network is solved by combining preset constraints, an AC / DC power transmission network planning scheme including an AC power transmission line planning scheme, a traditional DC power transmission line planning scheme and a current limiter configuration scheme is obtained, and an optimal balance point of economy and reliability is found in multi-scene analysis.

The application discloses a D-T hybrid multi-port DC fault current limiter topology structure and a control method thereof, and belongs to the technical field of DC power transmission and distribution. The fault current limiter is composed of a current limiting branch, an energy consumption branch and a control branch. The current limiting branch contains multiple current limiting inductors; the energy consumption branch includes two branches in which thyristor valve groups and energy consumption resistors are respectively connected in series, and one of the thyristors is replaced by an IGBT; and the control branch is composed of multiple groups of unidirectional diode valve groups. The control method comprehensively judges by monitoring the line current change in real time and combining the DC circuit breaker tripping signal to distinguish between real faults and system disturbances and control corresponding power electronic devices to act. The application adopts a mixed configuration of diode valve groups and thyristors, and is supplemented by key IGBTs, thereby significantly reducing the number of required fully controlled devices under the premise of guaranteeing the multi-port collaborative current limiting and reliable shutdown capability, and having the advantages of low cost, high reliability, and the like.

The invention discloses a method for estimating the maximum bearing capacity of renewable energy sources of a power grid, and the method comprises the steps: building a power grid operation model based on an AC optimal power flow and constraint conditions, and enabling the constraint conditions to comprise a node power balance constraint, a power transmission line thermal limit constraint, a voltage and phase angle stability constraint, and a power output constraint; carrying out battery energy storage constraint and short-circuit current constraint; constructing a collaborative objective function, wherein the objective function comprises maximization of renewable energy and energy storage system bearing capacity and minimization of construction cost; and solving the model by adopting a mixed artificial rabbit sine and cosine algorithm, and outputting a globally optimal solution. The invention provides a scientific and effective method for collaborative planning of renewable energy and stored energy in a power system and matched optimization of a power transmission line and a fault current limiter, and the characteristics and advantages of the scheme are clarified by implementing the effectiveness of an example verification model.

The application discloses a fault current limiter input method based on a voltage drop criterion and belongs to the technical field of power system fault protection, which comprises the following steps: collecting three-phase voltage instantaneous values of a fault current limiter installation point and calculating zero sequence voltage; synchronously calculating real-time voltage amplitude and voltage change rate; comparing the real-time voltage amplitude and the voltage change rate with preset criteria and combining zero sequence voltage auxiliary criteria to determine a ground fault; quickly opening a switch to input a current limiting reactor when the fault occurs; and closing the switch to exit the current limiting reactor after the fault is eliminated. The application adopts a comprehensive design of double main criteria of voltage amplitude and voltage change rate plus zero sequence voltage auxiliary criteria, can accurately distinguish a ground fault from normal fluctuations of a power grid, avoids misjudgment and missed judgment, has a quick sampling response, realizes quick input of current limiting by cooperating with a quick switch, can be self-adaptively adjusted according to actual power grid parameters and operating conditions, can effectively suppress a fault current peak value, prevents power equipment from being damaged, and practically improves the safe and stable operation level of a power system.

The invention belongs to the field of fault analysis, and discloses an index evaluation method and system for evaluating the fault ride-through capability of a direct-current fault current limiter, and the method comprises the steps: uniformly presetting bipolar short-circuit fault points in a target flexible direct-current power transmission system model, and determining a fault analysis time interval; the fault response processes under the two working conditions that the current limiter is connected and the current limiter is not connected are kept consistent on the time scale, so that a unified analysis basis is provided for comparison and evaluation among different working conditions; according to the method, bipolar short-circuit fault simulation is carried out under the same fault condition, and the state quantity of the system is obtained, so that the influence of the short-circuit fault on the voltage, current and power of the system can be completely described under the two conditions of a current limiter and a non-current limiter, and information loss caused by evaluation only depending on a single electrical quantity is avoided.

This invention relates to the field of power system fault protection technology, and particularly to a hybrid excitation type saturated iron core AC fault current limiter, comprising: a closed-loop 9-limb iron core, which adopts a three-phase three-limb equivalent structure and has a permanent magnet embedded inside; first and second AC coil groups, both wound on the closed-loop 9-limb iron core, with one end of the first AC coil group connected to one end of the AC power supply group and the other end connected to one end of the second AC coil group; first and second DC coil groups, both wound on the closed-loop 9-limb iron core, with one end of the first DC coil group connected to the positive terminal of the DC power supply group and the other end connected to one end of the second DC coil group, and the other end of the second DC coil group connected to the negative terminal of the DC power supply group; and a transient component energy discharge circuit group, one end of which is connected to the other end of the second AC coil group and the other end of which is connected to the other end of the AC power supply group. This effectively reduces the impact of the DC component of the short-circuit current on the normal operation of the fault current limiter.

The invention discloses a collaborative optimization configuration method and system for parameters of a current limiting device of a direct-current power grid, and the method comprises the steps: obtaining an actual topological structure of the direct-current power grid, and building a numerical solving model of the direct-current power grid based on the actual topological structure; determining a lower limit and an upper limit of the value of the current limiting reactor based on the direct current power grid numerical solution model; initializing the value of the current-limiting reactor, and determining the reference value of the current-limiting reactor; calculating direct-current power grid fault current under different fault current limiter values under the current reference value of the current limiting reactor, and obtaining a fault current limiter configuration scheme when the direct-current power grid fault current is smaller than or equal to the maximum breaking current; selecting the configuration scheme with the lowest cost as an alternative scheme; updating the reference value of the current-limiting reactor, and judging whether the updated reference value of the current-limiting reactor is greater than the upper value limit of the current-limiting reactor or not; and if yes, selecting an optimal scheme from the alternative schemes based on the configuration requirement, and performing parameter configuration based on the optimal scheme.

A distributed self-energy-taking cabinet type fault current limiter comprises a mechanism cabinet which is fixedly provided with a single-phase fast mechanical switch, a current limiting reactor and a self-energy-taking CT, the current limiting reactor and the self-energy-taking CT are matched with each other, and a trigger control device is arranged in the mechanism cabinet; wherein the current limiting reactor, the single-phase rapid mechanical switch and the self-energy-taking CT are coaxially nested in sequence from outside to inside; the current limiting reactor is electrically connected with the single-phase rapid mechanical switch in parallel; the output end of the self-energy-taking CT is electrically connected with the power supply input end of the trigger control device, and the self-energy-taking CT takes energy from a circuit when the single-phase rapid mechanical switch is normally closed and supplies power to the trigger control device; the signal output end of the trigger control device is in communication connection with a rapid mechanical switch mechanism of the single-phase rapid mechanical switch, and the on-off of the single-phase rapid mechanical switch is controlled by controlling the rapid mechanical switch mechanism.

The application discloses a kind of multiport adaptive direct current fault current limiter, the multiport adaptive direct current fault current limiter includes multiple magnetic core units and circuit unit, wherein, one end of multiple magnetic core units is connected with corresponding direct current port by corresponding direct current circuit breaker, the other end of multiple magnetic core units is connected to high-voltage direct current bus;Circuit unit includes diode bridge circuit and external freewheeling branch, wherein, the midpoint of each bridge arm of diode bridge circuit is respectively connected with the one end of each magnetic core unit, the common cathode end and common anode end of diode bridge circuit are respectively connected with external freewheeling branch to form energy consumption loop.The application can realize the bidirectional, fast, adaptive limitation for the short-circuit fault current of multiport flexible direct current system.

This invention provides a fault current limiter, a fault current limiter control method, a computer device, and a medium. The fault current limiter includes: a main branch for providing a power flow path when the current value in the DC line is less than or equal to a preset current value; and a first commutation branch, or a second commutation branch, for transferring the current in the DC line from the main branch to a resistor current-limiting branch when the current value in the DC line is greater than the preset current value; both the first and second commutation branches contain commutation capacitors; the voltage polarity of the commutation capacitor when the first commutation branch is activated is opposite to that when the second commutation branch is activated; and a resistor current-limiting branch for providing a power flow path when the current value in the DC line is greater than the preset current value, wherein the impedance in the resistor current-limiting branch is greater than that in the main branch. This invention can handle multiple fault currents and solve the problem of reversed voltage polarity of the commutation capacitor.

This invention discloses a temperature and pressure prediction and graded prevention and control system and method for arcing faults inside ring main units, belonging to the field of high-voltage switchgear safety protection technology. This invention deploys multi-physical quantity sensor modules in the arcing risk compartment to collect pressure, temperature, and arc light signals in real time; utilizes a temperature and pressure dynamic coupling prediction algorithm built into the edge computing unit to quickly predict the peak arcing pressure and assess the hazard level; and activates active suppression devices according to the severity level. Level 1 suppression uses an ultra-fast-acting fault current limiter to limit the fault current within 1ms, while level 2 suppression involves directional injection of CO2 insulating gas into the fault compartment to achieve rapid arc extinguishing. This invention transforms arcing faults from passively withstanding them to actively predicting and graded suppression, achieving arc extinguishing within 5ms, significantly reducing the risk of cabinet rupture, and is compatible with environmentally friendly gas-insulated ring main units such as those using dry air, ensuring safe operation and maintenance and reliable equipment operation.

The application provides a bidirectional controllable fault current limiter and a bidirectional controllable fault current limiter control method. The bidirectional controllable fault current limiter comprises a main flow branch, a commutation branch and a current limiting branch. The main flow branch is used to provide an electric energy flow path when the current value of the current in the DC line is less than or equal to a preset current value. The main flow branch comprises a first bridge arm and a second bridge arm, and the half-controlled devices in the first bridge arm and the second bridge arm are arranged in opposite directions. The commutation branch is used to transfer the current from the main flow branch to the current limiting branch when the current value of the current in the DC line is greater than the preset current value. The current limiting branch is used to provide an electric energy flow path when the current value of the current in the DC line is greater than the preset current value, and the impedance in the current limiting branch is greater than the impedance in the main flow branch. Through the application, the cost of the bidirectional fault current limiter is reduced, and the topology structure is simplified.

This invention discloses a method and system for selecting fault current limiters in multi-infeed DC receiving-end power grids, relating to the field of fault current limiter technology. The method includes the following steps: constructing a network model of the multi-infeed DC receiving-end power grid, the network model including the topology relationship between the AC and DC sides, converter station connection relationships, line parameters, and candidate locations for setting fault current limiters; determining network structure information under various operating conditions based on the network model; and acquiring the power grid's operating data and fault data; and generating a scenario set covering different operating conditions based on the operating data and fault data. This invention improves upon the traditional method of fault current limiter location selection in DC receiving-end power grids, which largely relies on experience-based judgment and suffers from low accuracy and poor deployment efficiency due to a lack of systematic quantitative analysis.

The invention belongs to the field of power distribution, and relates to a DC power distribution network fault current limiter and a current limiting method, and the DC power distribution network fault current limiter comprises a current limiting resistor, a bypass switch and a control system. The current-limiting resistor is connected in parallel with the bypass switch; when the main loop is normal, the control system controls the bypass switch to be in a closed state and is used for bypassing the current-limiting resistor; and when the main loop is over-current, the control system controls the bypass switch to be in an off state, and the current-limiting resistor is connected to the main loop according to a resistance value R calculated by the control system. The simplified design of the primary system of the DC power distribution network fault current limiter not only reduces the manufacturing cost, but also simplifies the installation and maintenance process, improves the reliability and economical efficiency of the equipment, and is beneficial to wide popularization and application of the equipment. The application of closed-loop tracking control of the control system enables the current limiter to quickly respond when a fault occurs, effectively limits the diffusion of fault current, and protects sensitive equipment in a power grid from being damaged.