Abstract: The present invention relates to a differential protection method for bridge circuit in current converter control system, including the steps of: 1). obtaining sample values of the three-phase current for the current converter control system at AC side thereof, and calculating the absolute value of each sampling value respectively; 2). calculating a value of current at the AC side of the current converter control system; and 3). determining whether to perform a relay protection for the current converter control system according to the value current at the AC side of the current converter control system. The method of the present invention provided, is fast, convenient, and with a small amount of calculation. The current converter control system determines whether to perform a relay protection in a short time. Also it reduces the possibility that the equipment burned because of cannot break the circuit in time.

Abstract: The present invention has disclosed a wind power bundling control method after wind power and thermal power are connected to a power grid in the field of electric power system security technology, including regulating wind power output and thermal power output forward or backward; calculating the transient stability margin of the grid, load level index of element and voltage out-of-limit index of busbar after regulating wind power output and thermal power output respectively; calculating wind power/thermal power paying value according to the transient stability margin of the grid, load level index of element and voltage out-of-limit index of busbar after regulating wind power output and thermal power output; if wind power/thermal power paying value is larger than set threshold value, regulating wind power output and thermal power output backward/forward; if wind power/thermal power paying value is smaller than set threshold value, regulating wind power output and thermal power output forward/backward.

Abstract: An integrated high and low voltage ride through test system, comprising a primary system and a secondary system; the secondary system controls the primary system to realize information interaction, and is connected to a power grid and a wind generation set via an inlet wire switch cabinet and an outlet wire switch cabinet of the primary system; the integrated high and low voltage ride through test system actually simulates voltage drop and rise characteristics in a power grid failure, ensures that when generating a low voltage and a high voltage, the change of a voltage phase angle and power quality are consistent with actual power grid failure characteristics, and enables coherent low voltage and high voltage ride through capacity testing on the wind generation set in a primary test process.

Abstract: The present invention relates to a real time dynamic physics simulation device of flexible DC transmission system. The device includes simulated converter transformer, simulated AC field, simulated DC field, simulated converter reactor, simulated converter, and measurement and control cabinet chassis; the simulated AC field includes the vacuum switch I, the contactor I, resistors and the vacuum switch II connected orderly; the simulated DC field includes successively connected the vacuum switch contactor III and II; the simulated AC field is connected with said measurement and control cabinet chassis; Said converter transformer is set between said resistors and said vacuum switch II; Said simulated converter reactors and said simulated converter connected are set between the vacuum switch II and the vacuum switch III.

Abstract: The present invention discloses an extremum seeking-based control method for maximum output tracking of a wind turbine generator, mainly comprising three steps of first closed-loop feedback, second closed-loop feedback, and third closed-loop feedback. The method for resisting mechanical fatigue of a double-fed variable speed constant frequency wind turbine generator by controlling mechanical torque while capturing maximum wind energy provided in the present invention is applied to a double-fed variable speed constant frequency wind turbine system by improving the control based on sliding mode extremum seeking with the following effects that, with regard to the maximum wind energy tracking effect, the rotating speed can be quickly adjusted to keep the tip speed ratio ? as its optimum value after the wind speed changes, so that the wind energy utilization coefficient is restored to the maximum value.

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 is used to determine the power command value of each energy storage substation of the battery energy storage power plant, and send it to all the local monitoring and controlling modules; the local monitoring and controlling modules is used to calculate the power command value of each energy storage unit of the energy storage substations controlled by it, and sending it to each energy storage unit, and upload to the central monitoring and controlling module to store. Between the central monitoring and controlling module and the local monitoring and controlling modules, the data transmission and communication are carried out through communication networks; the communication networks adopt real time and non real time communication parallel network structure.

Abstract: The invention relates to an automatic checking method for clock synchronization, comprising the following steps: (1) regularly acquiring clock signals sent by a Beidou signal source, a GPS signal source and an SNTP signal source; (2) performing subtraction to the clock signals of the Beidou signal source and the GPS signal source and evaluating the absolute value of the difference; at the same time, performing subtraction to the clock signals of the Beidou signal source and the SNTP signal source and then evaluating the absolute value of the difference and finally judging the results of the two differences; and (3) constantly repeating steps (1) and (2). The operations in the present invention can efficiently avoid the problems in the existing technology, guarantee the consistency and accuracy of system time, and guarantee the stable and safe operation of the system and the normal operation of other power grid businesses.

Abstract: An electric vehicle for routing inspection of power transmission lines, includes a body; a running mechanism mounted to the body, comprising a front wheel and a rear wheel connected by a cross beam and rolling on the cable; an obstacle sensor and a cam rotatably mounted to the cross beam, the cam rotating to roll onto the cable after an obstacle is detected on the cable such that the front wheel is raised to a position above the cable, and the cam continuing rolling on the cable after the front wheel passes the obstacle such that the front portion of the cross beam falls back downwards and the front wheel then falls back onto the cable, a hanging seat rotatably hanging to the body and a control device at least partially disposed in the hanging seat and comprising a braking device.

Abstract: The present invention provides an intelligent power utilization communication product detecting system suitable for an intelligent power grid. The system includes: a simulation master station, including a master station computer and master station software and configured to perform communication data interaction with a detected acquisition terminal and determine the communication performance of the intelligent power utilization communication system according to the communication data interaction result; a remote wireless communication test and channel simulation subsystem, configured to test detected products; a local communication test and channel simulation subsystem, configured to perform channel environment simulation on a local communication channel between the detected products and complete communication performance test on the detected products; and a purification power supply subsystem, configured to provide electric energy and matched impedance and isolate external interference noise.

Abstract: A detection system of distributed generation islanding based on power frequency carrier, the detection system comprising: a power frequency carrier signal generating device; a power frequency carrier signal detection device; a signal coupling transformer; a substation bus; a distribution power generator (DG); and a safety isolation breaker, wherein the power frequency carrier signal generating device comprises a voltage and current monitor circuit, the power frequency carrier signal generating device is connected with the signal coupling transformer through four three phase four line power cables, and the signal coupling transformer is connected with substation bus through 3 power cables.

Abstract: The present invention provides an intelligent calibration system for backup-power automatic switching devices, including a power supply module, a control module for logic controls, a voltage output module and a current output module for outputting simulated voltage and current, a signal feedback module for sampling outputted voltage and current signals, a simulated circuit-breaker group, an auxiliary relay, a USB interface for communication, a keyboard for information input, a display module for information interaction and real-time panel presentation, an interface module to facilitate plug-in wires, an indicator light for indicating operation status and a computer for controlling the testing globally. The present invention facilitates easy and fast wiring, and conveniently displays operation interface and related information. The operation is intuitive and simple, overall test efficiency is improved.

Abstract: A closed circulating water cooling apparatus and method. The cooling apparatus comprises: an internal cooling apparatus, a plate heat exchanger, an ice thermal-storage auxiliary cooling apparatus. The internal cooling apparatus comprises an air cooler. The ice thermal-storage auxiliary cooling apparatus comprises an ice thermal-storage apparatus.

Abstract: A dispersed state monitoring device for distributed generation includes a power module, an input conditioning module, a data processing module and a network communication module which are connected one after another in this order. The power is input, via a civil plug and a 220V power socket, to the power module and the input conditioning module in the device at the same time. The power module ensures normal operation of the device through conditioning of a voltage. The input conditioning module is configured to condition input voltage signals, extract voltage transient-state and steady-state signals to be analyzed, and inputting the signals to the data processing module. The data processing module is configured to analyze the voltage transient-state and steady-state signals, judge the operating state of the distributed power source, and output a judging result to the network communication module. The result is output from the network communication module via a standard RJ45 Ethernet interface.

Abstract: The present invention provides a portable single-phase air bypass switch for live power distribution network, including a housing member, a positioning member, a conductive circuit member, a clutch member, a switch-closing member and a switch-opening member. The positioning member includes a positioning nut, positioning frames, and a positioning column. The conductive circuit member includes a conductive end cover, an upper conductive rod, a pressing sleeve, a coupling nut, a conductive sleeve pipe, a stationary contact, a movable contact, and a lower conductive rod. The switch-closing member includes a switch-closing energy-storage rod, a switch-closing energy-storage ring, a switch-closing spring, a switch-closing positioning pin, a switch-closing release ring, and an inner sleeve pipe.

Abstract: A low-frequency band suppression enhanced anti-reversal power system stabilizer is presented by the invention. Currently the widely used PSS2B power system stabilizer needs lead elements above Order 2 to meet the phase compensation requirement of DC blocking signal of active power, thus quickly increasing high-frequency band gain, restricting allowable total setting gain of PSS, limiting low-band gain and reducing low-frequency band suppression ability of power system stabilizer. The invention will add generator speed signal ? (which is treated by DC blocking element and corrected by parallel proportional differential PD) and active power signal Pe (which is treated by DC blocking element and gained by gain factor Ks3) to get equivalent synthetic mechanical power of power system stabilizer.

Abstract: Connection methods for UHVDC transmission at rectification side and at inversion side, UHV converter stations at rectification side and at inversion side, and an UHVDC transmission system are disclosed. The present invention employs a manner of multiple drop points to solve the problem of poor security stability of electric grid caused by feeding a large amount of power via one point.

Abstract: A method for controlling structure-borne noise based on a combined-type vibration isolation device includes the following steps: S1: determining a combined-type vibration isolation device as required according to parameters of a mechanical device to be isolated, and installing the combined-type vibration isolation device on a horizontal bearing surface; S2: vertically placing the mechanical device to be isolated on the combined-type vibration isolation device; S3: adjusting a mass of an intermediate balance weight block of the combined-type vibration isolation device; and S4: adjusting an inherent frequency of the combined-type vibration isolation device to be lower than a structural vibration sound transmission frequency generated in the operation of the mechanical device to be isolated.

Abstract: The present invention provides a method and an apparatus for determining separation efficiency of a cyclone separator. The method comprises: collecting solid particles separated by a cyclone separator; performing a particle size analysis for the collected solid particles; calculating feature parameters of the collected solid particles according to a result of the particle size analysis, wherein the feature parameters are values representing particle size and particle size uniformity of the solid particles; and determining a separation efficiency corresponding to the feature parameters of the collected solid particles as a separation efficiency of the cyclone separator, according to a predetermined correspondence between feature parameter and separation efficiency. The present invention avoids the difficulty in directly measuring the material concentrations at the inlet and the outlet of the cyclone separator and has a small interference with the apparatus.

Abstract: The present invention discloses a system and a method for controlling PCS voltage and frequency, wherein the system comprises a reference voltage converter, a phase-locked loop, a grid-side voltage converter, a voltage transformer, a first proportional integral controller, a second proportional integral controller, a coordinate converter and a SVPWM generator; a reference voltage converter is connected to an output terminal of a the phase-locked loop, and the output terminal of the phase-locked loop is further connected to a grid-side voltage converter; the grid-side voltage converter is connected to a high-voltage side of an isolating transformer of the electric grid via the voltage transformer; two output terminals of the grid-side voltage converter are respectively connected to the coordinate converter via two proportional integral controllers; an output terminal of the coordinate converter is connected to the SVPWM generator; an output terminal of the SVPWM generator is connected to a power switch of the

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.