State Grid Corporation of China, State Grid Smart Grid Research Institute and China Electric Power Research Institute | Date: 2014-10-29
A method for optimizing voltage self-adaption control based on IGBT series loss. The method comprises the following steps: (1) detecting a voltage at an IGBT end; (2) adjusting a main switching stage time; and (3) adjusting a preliminary switching stage time. By means of the method, when the IGBTs are connected in series, the voltage balance degree is improved, the switching loss is reduced, and the switching voltage stress is controllable.
Hamamatsu Photonics K K, Nanjing Guanglu Electronics Co. and China Electric Power Research Institute | Date: 2015-10-07
A single-core optical transceiver 1 is an optical transceiver for transmitting or receiving an optical signal through a single optical fiber 2. The single-core optical transceiver 1 has a light emitting device 13 for transmitting the optical signal and a light receiving device 12 for receiving the optical signal. The light emitting device 13 is an LED configured including a sapphire substrate 13b arranged on a light receiving surface 12a of the light receiving device 12 so as to be coaxial with the light receiving surface 12a, and a nitride semiconductor layer 13a laid on the sapphire substrate 13b. Even with the light emitting device 13 being arranged on the light receiving surface 12a of the light receiving device 12, the optical signal from the optical fiber 2 can be received on the entire area of the light receiving surface 12a, so as to adequately improve the light sensitivity.
Agency: Cordis | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2012-ITN | Award Amount: 3.93M | Year: 2013
A DC grid based on multi-terminal voltage-source converter is a newly emerging technology, which is particularly suitable for the connection of offshore wind farms. Multi-terminal DC grids will be the key technology for the European offshore SuperGrid. In this proposal, DC power flow, DC relaying protection, steady state operation, dynamic stability, fault-ride through capability, and impacts of DC grids on the operation of AC grids and power market will be studied. Systematic comparison of DC grid topologies and stability control strategies will be carried out. DC grids for offshore wind power transmission and onshore AC grid interconnection will be investigated. Operation and control will be evaluated using various simulation platforms and experimental test rigs. The achievements from the project will greatly contribute to integrating offshore wind power into the onshore AC grids in European countries and for the European Super Grid. The MEDOW consortium involves 11 partners (5 universities and 6 industrial organisations). Each institution in the consortium contributes various expertise on the manufacturing, design, operation, and control of multi-terminal DC grids. Three visiting scientists of outstanding international stature will be appointed to further strengthen the training capacity and quality of MEDOW. This project will recruit 12 early-stage researchers (ESRs) and 5 experienced researchers (ERs). These researchers will receive interdisciplinary and intersectoral trainings in different countries to improve career opportunities. Research results will be disseminated through publications, intellectual properties, and direct application in the industries. MEDOW offers a development path to researchers across Europe in the area of DC grids, in addition to fostering greater ties between industry and academia in this key development area.
State Grid Corporation of China, China Electric Power Research Institute, STATE GRID HEBEI Electrical POWER COMPANY, Henan Electric Power Company and Jiangsu Electric Power Company | Date: 2015-03-12
The present invention discloses a method for lightning stroke identification and location on optical fiber composite overhead ground wire. In the method, according to the property that the lightning stroke will cause a sudden temperature rise at the lightning stroke position on the optical fiber composite overhead ground wire, optical fiber resources in the optical fiber composite overhead ground wire and the high-sensitivity detection and high-precision event locating capability of a distributed optical fiber temperature sensor can be fully utilized. The distributed optical fiber temperature sensor is connected to a spare optical fiber in the optical fiber composite overhead ground wire, and the corresponding relation between the geographical position of the optical fiber composite overhead ground wire and the distributed temperature curve is established, and then the temperature data at the same position in the temperature curve at different moments are respectively compared to extract a sudden temperature change area. In addition, the temperature change of several positions adjacent to the sudden temperature change area in the temperature curve are compared to exclude interference factors in temperature measurement, so as to determine that the sudden temperature change is caused by instant heating from an external factor, namely the lightning stroke, and finally, the lightning stroke is identified and located in combination with the change of counting data of a lightning arrester.
Jiangsu Electric Power Company, State Grid Corporation of China, Hohai University, Nanjing Hehai Technology Ltd Company and China Electric Power Research Institute | Date: 2014-06-10
The present invention discloses a smart power distribution system and a method to progressively dispatch the power using the same. The method is characterized in that it is based on data collection and data analysis to develop a dispatch scheme. The method steps are all automatic and self-adaptive. The method can be executed in an unattended manner to automatically correlate real time data vs. historical data, planning data vs. operation data. Based on a long cycle periodical variation and short-term random variations in load, and taking into account the temporary load power supply and maintenance needs, a multi-stage progressive multiple time scales optimal dispatching method is developed, including the distributed power, micro-grids, energy storage devices, electric vehicles charge-discharge facility and other elements of the Intelligent power distribution systems, to achieve coordinated operation of the network, power, load resources to ensure a continuous safe and reliable smart power distribution system operated at high quality and efficiency.
China Electric Power Research Institute and State Grid Corporation of China | Date: 2015-04-22
The present invention relates to a low voltage ride through detecting device of grid-connected photovoltaic inverter, it comprises a current limiting reactor, short circuit reactors and a combination earth switch; Said current limiting reactor, said intermediate reactor-breaker unit, short circuit reactors and the combination earth switch are connected one by one in series; Said current limiting reactor is connected to 10/35kV grid; Said intermediate reactor-breaker unit and the combination earth switch are connected to the neutral point of high voltage side of reducing transformer respectively. The reducing transformer is inserted to grid-connected photovoltaic inverter. Under the circumstance that short circuit capacity remains unchanged, the device can satisfy the requirement of implementation of voltage sag with multiple amplitudes using a fewer reactors by changing the ratio of current limiting reactor and short circuit reactance via different switch modes of several circuit breakers, which make it qualified to detect the capability of Low voltage ride through of grid-connected photovoltaic inverter.
State Grid Corporation of China, China Electric Power Research Institute, Cepri Zhangbei Wind Power Research and Test Co. | Date: 2016-01-06
This invention relates to the new energy access and control field, in particular, relates to a kind of test system for mobile wind turbines power gird adaptability, which includes the grid turbulence generator and the integrated measurement-control device connected by the optical fiber, the grid turbulence generator connects between the medium voltage power gird and the wind turbines step-up transformer high voltage side; The integration of grid turbulence generator and integrated measurement-control device is installed in the container; The container includes the cooling system inside, said cooling system includes water cooling device and air cooling device. This invention can generate online real simulation normal power grid voltage deviation, frequency variation, three-phase voltage unbalance, voltage flicker and common grid disturbances in wind turbines step-up transformer high voltage side, collects and analyzes the real running data of the wind turbines, and processes tests and evaluations for the wind turbines power gird adaptability. The mobile structure facilities the transportation and installation between different wind farms, solved the field test and inspection problem of the wind turbines power gird adaptability under the condition of complex topography and transportation.
State Grid Corporation of China and China Electric Power Research Institute | Date: 2016-07-20
A GIS electronic instrument transformer test system based on opening-closing small capacity current of an isolating switch, in the GIS electronic instrument transformer test system that includes a high voltage test transformer connected to a BSG casing, a capacitive voltage divider, a load capacitor connected to the other BSG casing, an isolating switch between the two casings, a calibration primary transient test system and an to-be-tested electronic instrument transformer, wherein one end of a secondary converter is connected with the to-be-tested electronic instrument transformer, the other end of the secondary converter is connected with a merging unit, and the other end of the merging unit is connected with a fault recorder. When the isolating switch is opened and closed, a voltage value and a current valve of a high voltage bus are tested to compare with the output of the to-be-tested electronic instrument transformer. By means of the test system, electromagnetic environments of 110KV, 220KV and 500KV voltage levels in power transmission and outage processes can be simulated to load processes of opening-closing empty conducting wires and small capacity current of the isolating switch onsite, in order to generate similar onsite transient strong interference to check the electromagnetic protection performance of the electronic instrument transformer under the condition.
State Grid Corporation of China, Jiangsu Electric Power Company, State Grid Suzhou Power Supply Company, China Electric Power Research Institute and Nari Technology Co. | Date: 2014-12-16
The present invention discloses a system and a method for main distribution network graph/model/data integration based on remote access and information interaction. The system integrates graph information, model information, and real-time data of a main power transmission and transformation system into an application system by using processing methods such as remote access, SVG graphic file import, CIM model file import, an event service mechanism, and a message mechanism, to minimize mutual information dependence when the application system imports the model information, the graph information, and the real-time data in the main network power transmission and transformation system.
Li X.,China Electric Power Research Institute
IET Renewable Power Generation | Year: 2012
The energy storage system (ESS) is the current, widely popular means of smoothing intermittent wind power (WP) generation to regulate output power uncertainty in a wind power generation system (WPGS). This study presents a novel Kalman filter (KF) application method for smoothing the power-output fluctuation of a WPGS based on a battery energy storage system (BESS). A fuzzy logic control method was added to a first-order KF with feedback control of the battery state of charge (SOC). On this basis, the smoothing power output of the hybrid wind/battery power system could be adaptively regulated based on the SOC, and consequently, the battery SOC could be effectively managed according to the charge- and WP-output levels. The effectiveness of the proposed control strategy based on the fuzzy adaptive KF was verified using MATLAB/SIMULINK software and simulation tests. © 2012 The Institution of Engineering and Technology.