Abstract: A method for obtaining a relation between a winding state and a leakage reactance parameter of a transformer by using simulation software is provided. The method includes: establishing a simulation transformer based on a size of a physical transformer; setting parameters of the simulation transformer, setting a winding of the simulation transformer in a predetermined winding state; obtaining a predetermined number of values of a leakage reactance parameter of the simulation transformer in the winding state; and performing statistics on all the values to obtain a value range of the leakage reactance parameter in a case that the winding is in the winding state. The value range is used as a value range of a leakage reactance parameter of the physical transformer in a case that a winding of the physical transformer is in the winding state.

Abstract: A system for staring a large-scale power load in a micro grid comprises a PCC grid connection switch, a micro grid alternating-current bus, an active power filter (APF), an energy storage inverter, an energy storage battery, a current-limiting resistor R, contactors K1-K3, a time relay KT, a power supply relay board, a micro grid maser control system, a frequency converter rectifying circuit, a frequency converter filter circuit, and a frequency converter inverter circuit. There are the advantages: an output torque of a power load can be effectively improved by using a variable frequency starting apparatus, and a starting current is also small; the provided method can effectively reduce a harmonic current when a variable frequency starting apparatus starts a power load, the phenomenon that two power sources supply power on a direct-current side of the variable frequency starting apparatus at the same time is avoided, thereby improving the stability and the economy of a micro grid.

Abstract: A maintenance tool for an insulator of a direct current transmission line comprises clamping devices and a tensioning device. The clamping devices are mounted at the two sides of the insulator through clamping, and the tensioning device is connected between the clamping devices. The clamping devices comprise a closed clamp (1), a single serial clamping device (2) and a wire end clamping device (30). The clamping device has advantages such as strong overall strength and bearing capacity, small size, light weight, and reliable working, and can be applied to replacement of various insulators on the direct current transmission line, reliably ensuring safe commissioning and regular maintenance of transmission lines.

Abstract: A power frequency parameter simulation system for a power transmission line and a control method thereof, the system includes a simulation main circuit (1), an interference power supply (2) and a procedure controller (3). In the system, a power frequency parameter of a 10 to 100 kilometers of 500 kV power transmission line is simulated in a lumped parameter manner; and the control method includes the following steps of: a step to detect the automatically zeroing during starting up, a step to control the reduction of the length of a simulation line and a step to control a simulation interference voltage. A long-distance power transmission line is realized to be moved into a room and be tested by means of the power frequency parameter test system, so the various inconveniences of on-site measurement are avoided.

Abstract: A method, apparatus and system for suppressing low frequency oscillation in a power system. The method includes determining a system transfer function of an interconnected power system section in which a variable frequency transformer (VFT) is located; determining a damping controller parameters according to the system transfer function; and suppressing low frequency oscillation of the power system by means of the VFT based on the damping controller parameter. The objects of the method, apparatus and system are definite: optimizing the damping controller parameter can be achieved by simply tracking and analyzing the response of the system to disturbance, without the need to understand the configuration and parameters of the system or solve complicated power system equations, which has a better effect in suppressing low frequency oscillation in the power system and is advantageous for improving the safety and stability level of the power grid.

Abstract: The invention relates to a method and system for smoothing the energy storage wind and photovoltaic power fluctuation based on rate control, including: reading and processing data; determining the signal change rate of the dynamic slope limiter; calculating the smoothing target value of the wind and photovoltaic total power; calculating total power demand of battery energy storage power station; and outputting data. The invention can effectively suppress wind and photovoltaic power fluctuation under the fluctuation rate limited value, can effectively smooth wind and photovoltaic power output. Thus it smoothens wind and photovoltaic power output, reduces the energy storage battery burden, and effectively controls battery energy storage power station system.

Abstract: A single-phase-to-earth fault processing device for a neutral non-effectively grounded distribution network includes a split-phase arc quenching device connected between earth and a three-phase bus of the distribution network, and a controller with an input end connected with a single-phase-to-earth phase selection device of the distribution network. The split-phase arc quenching device includes a multiphase switching device which operates independently for each phase, and a fuse connected in series with the multiphase switching device. The controller is for controlling opening and closing of three single-phase switches, in the multiphase switching device. A single-phase-to-earth fault processing method firstly controls the split-phase arc quenching device to preprocess the fault. If the fault still exists, through a ground resistor a zero-sequence current is generated on a fault line.

Abstract: A method and a system for register clearing in data flow analysis in decompilation are provided. The method includes: reading all function statements in a code file; sequentially judging each of the read function statements, and creating a binary tree and inputting the function statement into the binary tree in a case that the function statement includes a register name; sequentially judging each of the function statements including the register name, and performing an elimination process on the created binary tree to remove the register name from the binary tree in a case that the function statement includes a right child end tag of the binary tree, to generate a simplest binary tree; and generating a function statement in high-level language based on the simplest binary tree. All function statements can be read at a time and multiple reading and writing are avoided in the invention.

Abstract: This invention publishes a fault diagnosis and location system for transformer core looseness, consists of vibration sensors, data collection and computer. It is of power transformer fault intelligent diagnosis technology technical field. Fault diagnosis and location method uses three vibration sensors positioned on the top of transformer tank, to obtain vibration signal, uses signal processing to analyze the signal, and obtains fault characteristics of the transformer core looseness. The characteristics respectively are 50 Hz, 150 Hz and 300 Hz frequency components, in which 300 Hz is main feature. When they reach a certain value at one position, it suggests that transformer core looseness near this position. By the comparison of differences among signals of three positions, fault location can be done. This invention manifests fault characteristics accurately and detects core looseness efficiently.

Abstract: The present invention relates to a monitoring and controlling system and method for megawatt level battery energy storage power plant, which includes a central monitoring and controlling module and local monitoring and controlling modules, between the two modules adopts real time and non real time communication parallel network structure to communicate with each other.

Abstract: A wet limestone flue gas desulfurization slurry stabilizer and a method for using the same are disclosed. The stabilizer consists of lime, sodium formate and an antifoaming agent, the components and mass percentages thereof are as follows: lime, 30% to 70%, sodium formate, 15% to 40%, the antifoaming agent, 15% to 40%. The method for using the desulfurization slurry stabilizer comprises: preparing the slurry stabilizer into a homogeneous liquid having a mass concentration of 10% to 30% with water or desulfurization slurry outside a desulfurization tower, and spraying the homogeneous liquid into the absorption area and the reaction area of the desulfurization tower using a pump and a slurry atomizing and spraying device.

Abstract: A mechanical fault indicator of the automatic reset includes the core, the dial, the lock, the indicating rods, and the shell. The core includes the clip-on core, fixed core, connecting core and movable iron core. The pointer includes the indicating axis of rotation, the pointer connection and the indicating rod. The lock includes the lock axis of rotation, the lock hook and balancing weight. When using the indicator, clip the wire of the transmission line into the two-part clip-on core. When a short circuit fault happens, the indicating rod falls out of the housing, of which the action indicates failure. When the circuit is back to normal, the indicating rod resets automatically. The indicator has the advantages of: low cost, long service life, purely mechanical, no circuit and battery, and the installation is simple and convenient.

Abstract: A combined-type intelligent terminal wiring device and a plug device are provided. The wiring device includes a top wiring terminal board, a bottom wiring terminal board and a combined-type socket. An interior of each terminal of the combined-type socket has a spring-leaf structure, and each spring leaf includes an upper spring leaf and a lower spring leaf which are conductively connected via a contact surface. The top wiring terminal board has one end configured to connect the upper spring leaf, and the bottom wiring terminal board has one end configured to connect the lower spring leaf. The plug device includes a plug and a wiring terminal, the plug is located at a front end of the plug device and is a conductive metallic sheet, and the wiring terminal is located at a rear end of the plug device and has one end connected to the conductive metallic sheet.

Abstract: A power grid development stage division method based on Logistic model. The method uses per capita household power consumption as the primary characteristic value in power grid development according to correlation analysis results and deduces a power grid development stage division theory that power grid development generally goes through a primary stage, a fast-growing stage, a posterior stage and an equilibrated stage on the basis of the Logistic model. s The provided power grid development stage division method offers decision references to planning, construction, operation and maintenance of power grid and is of great significance in timely switching work priorities, sticking to work trend and ensuring sustainable development during power grid development.

Abstract: A grounding grid breakpoint diagnostic method for a transient electromagnetic method, based on a transient electromagnetic detection apparatus. The method comprises: (101) disposing a test line at a position above a grounding grid to be diagnosed on the ground, and determining coordinates of a detection point; (102) obtaining information about coordinates of the detection point, and coinciding the center of the transient electromagnetic detection apparatus with the coordinates of the detection point; (103) performing, by the transient electromagnetic detection apparatus, measurement along the test line point by point, so as to obtain measurement data; (104) processing, by using diagram forming software, the measurement data to form a longitudinal resistivity cross-section diagram of the detection point according to a preset formula; (105) determining whether a breakpoint occurs at the detection point according to the longitudinal resistivity cross-section diagram.

Abstract: The invention relates to Modular multilevel converter valve protection method, the modular multilevel converter valve consists of 6 arms, the arm includes sub modules, 1 arm is controlled by 1 control host, 6 control hosts is controlled by 1 summary control host, the method of the invention includes that the arm realizes locking sub module, bypass sub module, trip requests and system switching request and the summary control host implements summary and control response. The invention improves the reliability of two protection system through the use of dual redundancy protection method, clears the protection division through the layered protection frame of the upper summary control host and multi arm control host. And finally, it improves the whole safety and reliability of the modular multilevel converter valve.

Abstract: The present invention relates to a basic function unit of voltage source converter, which is characterized in that the basic function unit includes a switching device function module, a by-pass function module, a switch protection function module, a secondary control and protection function module, and a energy storage unit. The secondary control and protection function module, the energy storage unit and the by-pass function module are all fixed on the motherboard, there is a slide rail at the bottom of the motherboard, the motherboard can move back and forth on the slide rail. The voltage source converter based on that unit is highly modular, insensitive to switch device parameters, lower output voltage change rate, and smaller dv/dt stress of equipment, smaller noise, without filter, convenient installation and maintenance.

Abstract: An optical fiber core butting apparatus comprises a butting panel (1) with multiple butting devices including butting holes (11), optical fiber core butting connectors and mechanical hands (3); the optical fiber core butting connectors comprise a wire-line connector (21) and a cord-line connector (22); the wire-line connector (21) comprises a first slide bar (211), a first wire-line core connector (212) and a second wire-line core connector (213), and the input terminals and the output terminals of the first and second wire-line core connectors (212, 213) are both connected by connecting fibers; the cord-line connector (22) comprises a second slide bar (221), a first cord-line core connector (222) and a second cord-line core connector (223), and the first and second cord-line connector (222, 223) are connected by a connecting fiber; the mechanical hands (3) are used for holding the core connectors and driving the core connectors to move.

Abstract: A renewable energy-based hybrid bi-directionally interactive DC traction power supply system includes two traction substations. Each substation includes transformers, rectifiers, bidirectional AC-DC converters, a DC bus, a catenary, a steel rail and a section post. A DC bus between two adjacent traction substations is provided with a DC renewable energy system constructed by an electric vehicle charging-discharging system, a distributed generation and more than one low voltage DC microgrid. The DC renewable energy system is connected to the DC bus between two adjacent traction substations through a high voltage DC bus, thus a DC circular microgrid being formed in a power supply section post. The electric vehicle charging-discharging system is formed by more than one bidirectional DC-DC charging-discharging equipments which are intended for in connection with the power batteries of the electric vehicle.

Abstract: A method for quickly carrying out effective automatic interlocking logic detection based on a GOOSE communication mechanism, comprising: introducing an automatic system device model and configuration satisfying the IEC61850 standard, and simulating a GOOSE communication behavior in which an intelligent electronic device acts as a quick packet transmitter and receiver, so as to realize the closed-loop detection function by independent publishing and feedback monitoring GOOSE information.