State Grid Corporation of China is the largest state-owned electric utilities company in the world. It transmits and distributes power in China. The power distributor is headquartered in Xicheng District, Beijing and manages distribution from subsidiaries in Northern China, Northeastern China, Eastern China, Middle China and Northwestern China.After the electricity "Plant-Grid Separation" reform in early 2002, the assets of State Electric Power Corporation were divided into the five "power generation groups" that retained the power plants and five regional subsidiaries belonging to the State Grid Corporation of China in Beijing. The company is the seventh largest in the world according to the 2011 Fortune Global 500 ranking. Wikipedia.
Xj Group Corporation, XJ Electrical CO., Xuchang XJ Software Technelogy Co and State Grid Corporation of China | Date: 2016-09-09
Sampling implementation method and device based on conventional sampling GOOSE trip mode. CPU of master NPI plug-in, after receiving a second pulse, transmits sampling pulse generation time and a transmission enable bit to FPGA of the master NPI plug-in at a fixed interval; after detecting the transmission enable bit, the FPGA of the master NPI plug-in judges whether time of its internal timer is greater than/equal to the sampling pulse generation time, if yes, generates a sampling pulse to FPGA of collection plug-in; after receiving sampling pulse, the collection plug-in carries out A/D sampling, and transmits sampled data to the master NPI plug-in; when detecting that all A/D samplings are completed, the master NPI plug-in transmits data packets to protection CPU plug-in. The device includes an MMI plug-in, a protection CPU plug-in, a master NPI plug-in and a collection plug-in. Protection maloperation is thereby reduced.
State Grid Corporation of China, Huainan Power Supply Company of State Grid Anhui Electrical Power Corporation and NARI Group | Date: 2015-08-24
The invention discloses a fault point locating method of hybrid lines based on analysis of comprehensive characteristics of single-end electric quantity and transient travelling waves, which mainly includes steps: phase-model transformation; looking up initial time of failure; extracting timing window data after the initial time; searching a reflected wave from the fault point and a reflected wave from a demarcation point in the timing window; and judging properties of the reflected waves. After failure of a hybrid line with cable and overhead line, by identifying and comparing comprehensive characteristics of the reflected wave from the fault point, primary and secondary reflected waves from the demarcation point in the single-end transient voltage and current travelling waves, it is rapidly judged whether the fault point is located in the overhead line segment or the cable segment, which is used to assist in switching decision for line reclosing.
Xj Group Corporation, XJ Electrical CO., State Grid Corporation of China and Xuchang XJ Software Technology Co. | Date: 2016-09-22
A distributed test method applicable to a system-level test of intelligent high voltage equipment. The method includes: firstly, carrying out unified modeling on test equipment behaviors according to test requirements, and generating a general test case for ensuring accuracy and coordination of test behaviors and test time sequences under various work conditions; then, extracting, according to a feature element of role defining, sequence states of same roles from the general test case, and recombining the sequence states according to an execution sequence so as to form test sub-cases of the roles; finally, executing, by each piece of test equipment, corresponding test sub-cases to achieve cooperative linkage by means of information interaction, so as to accomplish entire process simulation of the test conditions.
State Grid Corporation of China, Shandong Electric Power Research Institute and Shandong Luneng Intelligence Technology Co. | Date: 2017-01-11
The present invention discloses a centralized monitoring system for transmission line inspection of unmanned aerial vehicles, including a centralized monitoring subsystem, mobile substations and unmanned aerial vehicle flight platforms. The centralized monitoring subsystem is connected with the mobile substations in a one-to-many mode, the mobile substations are connected with the unmanned aerial vehicle flight platforms in a one-to-one mode, in a manner of combining remote centralized monitoring with local monitoring, centralized monitoring is carried out on the flight states, pod states, transmission lines, inspection results and other information of more than one accessed unmanned aerial vehicle for line inspection, personnel, equipment and inspection lines involved in an unmanned aerial vehicle inspection task are planned and managed, and centralized management and defect diagnosis are carried out on the inspection results, so as to reinforce the informatization and automation degrees of the unmanned aerial vehicle inspection process and inspection result processing, improve the unmanned aerial vehicle inspection efficiency, and provide technical supports for achieving safe and reliable operation of unmanned aerial vehicle line inspection.
State Grid Corporation of China, State Grid Smart Grid Research Institute and North China Grid Company | Date: 2017-02-15
A passive high-voltage direct-current circuit breaker and an implementation method therefor. The high-voltage direct-current circuit breaker is connected in a direct-current system in series, and comprises an energy absorption branch, a main branch and a current transfer branch which are connected in parallel, wherein the current transfer branch comprises first current transfer branches (T1, T2) and second current transfer branches(T3, T4); the energy absorption branch is composed of a nonlinear resistor (MOV); and the main branch comprises at least two groups of high-speed mechanical switches (Kl, K2) and at least two groups of full controlled device modules which are connected in series. Since the circuit has a simple topology structure, is simple and convenient to control, and is flexible to apply, the energy required by injecting a current into a capacitor can be obtained from a system without configuring an auxiliary power source, thereby improving the reliability of an apparatus. The used power electronic devices are mainly half controlled thyristors, so that the series connection technology is mature, the capability for current segmentation is strong, the level of withstand voltage is high, the expansion capability is strong, and the costs of devices are low.
State Grid Corporation of China, State Grid Smart Grid Research Institute and China Epri Electrical Power Engineering Co. | Date: 2017-04-19
A modular multi-level flexible direct-current topology circuit suitable for fault ride-through, comprising a module cascading circuit, a voltage conversion circuit and a compensation circuit, wherein after being connected to the voltage conversion circuit in parallel, the module cascading circuit is connected to the compensation circuit in series. The direct-current topology circuit can achieve alternating-current and direct-current fault ride-through simply and effectively, thereby being suitable for application in the field of high-voltage high-capacity direct-current overhead lines.
State Grid Corporation of China, State Grid Smart Grid Research Institute and China Epri Electrical Power Engineering Co. | Date: 2016-09-28
A commutation apparatus based on a controllable commutation inductor (3), and an implementation method therefor. The commutation apparatus uses a three-phase half-bridge structure. The three-phase half-bridge structure consists of serially connected commutation units. Each of the commutation units comprises a converter transformer and a converter inverter (2). A commutation inductor is serially connected between the valve side of the converter transformer and the converter inverter. A controllable inductor in the commutation inductor is used together with a control protection system in a converter station. When the converter station normally operates, a switch is turned off, and the controllable inductor is comprised in the commutation inductor; when the control protection system in the converter station detects a commutation failure, the switch is turned on, so that a leakage inductance value of the commutation inductor is lowered, the commutation angle is reduced, and the turn-off angle is increased. The commutation apparatus improves a commutation feature of a converter valve on an inverter side when a commutation failure occurs, and the commutation apparatus has the advantages of requiring less elements, is easy to implement, and requiring low cost.
State Grid Corporation of China and Laiwu Power Supply Company Of State Grid Shandong | Date: 2016-07-27
The invention discloses a power restoration method for a power distribution network with multi-faults. The method overcomes the shortcomings that a traditional fault restoration method for the power distribution network can not solve multi-faults. The method comprises the steps of performing multi-fault judgment on multiple faults not completely processed, to form a plurality of multi-faults and a plurality of single-faults; then performing independent fault restoration area division on the multi-faults, and performing power restoration on independent fault restoration areas one by one; and after the multi-faults are processed, performing power restoration on each single-fault. According to the invention, the power restoration efficiency is greatly improved, thus contributing to the real-time performance of power restoration; the factor of load balance is considered when common power restoration lines are decoupled, so that the load rates of the power restoration lines participating in power restoration are more approximate after fault restoration, and therefore the power supply reliability of the power distribution network is improved.
Xj Group Corporation, Xuchang Xj Software Technologies Ltd, XJ Electrical CO., Xi'an Jiaotong University and State Grid Corporation of China | Date: 2016-03-21
The invention relates to rapid online diagnosis method of high-power rectifier open-circuit fault, including: 1) collecting actual output direct current value i_(d)(t_(0)) and three phase input electric current instantaneous values i_(a)(t_(0)), i_(b)(t_(0)) and i_(c)(t_(0)) of rectifier at t_(0 )moment, and calculating theoretical output direct current value i_(d) of the rectifier according to i_(a)(t_(0)), i_(b)(t_(0)) and i_(c)(t_(0)); 2) comparing i_(d) (t_(0)) and i_(d)(t_(0)), when i_(d) (t_(0)) is not more than k1i_(d)(t_(0)), comparing absolute value of maximal three phase input electric current instantaneous value and pre-set threshold value A_(1), if the maximal three phase input electric current instantaneous value is not less than A_(1), the rectifier appears open-circuit fault. The inventive method is simple, with no complicated step for performing fault diagnosis, of course, the short fault diagnosis period and tripping protection occupation time is short, but it also can protect the rectifier effectively and prevent equipment damage from longtime working under fault condition.
Zhejiang Electrical Power Test, Research Institute, State Grid Corporation of China and NR Electrical Co. | Date: 2016-04-13
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 P_(e )(which is treated by DC blocking element and gained by gain factor K_(s3)) to get equivalent synthetic mechanical power of power system stabilizer. The actual active power signal gained by gain factor K_(S1 )can meet the requirement of phase compensation through Order 1 lead and lag elements, thus increasing allowable total setting gain of PSS and improving the ability of low-frequency band oscillation suppression.