Abstract: Disclosed is a street lamp control system, which cuts off power sources only around an abnormal street lamp where an electric leakage or dangerous situation occurs and allows the rest street lamps to be kept being turned on. The street lamp control system is positioned in a region divided by a plurality of areas where a predetermined number of street lamps are installed. A distribution panel is installed in each center of the areas, and includes two power source control switching circuits for controlling right and left power sources of the corresponding areas. The power source control switching circuit of the corresponding distribution panel turns off the right and left street lamps including the corresponding street lamp when an abnormal state is sensed on a specific street lamp of a specific area, and a power is supplied to the right and left street lamps to be turned on excluding the abnormal street lamp.

Abstract: Disclosed is a controller of a grid coupled type doubly-fed induction generator having a multi-level converter topology, which can control the doubly-fed induction generator having a high voltage specification and can perform a fault ride-through function, an anti-islanding function and a grid voltage synchronization function required for a dispersed power generation facility. The controller makes a H-bridge multi-level converter generate a three-phase voltage waveform resulted from the structure that single-phase converters each being composed of a 2-leg IGBT are stacked in a serial manner, and controls a rotor current so as to make the rotor coil of the doubly-fed induction generator in charge of a slip power only. The boost converter is composed of a 3-leg IGBT and a boost inductor generating a direct current voltage of its source required for the H-bridge multi-level converter.

Abstract: Disclosed is an X-ray tube system with a disassembled carbon nanotube substrate for generating micro focusing level electron beams. A housing provides a vacuum space. An anode forms an electric field by a voltage applied from the outside and accelerates the electrons emitted from the cathode to reach the anode itself. A carbon nanotube substrate used as a cathode corresponding to the anode. A cathode plate supports and fixes the carbon nanotube substrate and applies a voltage to the carbon nanotube substrate. A sample probe is installed assemblably/disassemblably in the housing. A grid electrode is installed in front of the carbon nanotube substrate and extracting electrons from the carbon nanotube substrate in an easy manner. An electron focusing lens focuses the electrons passed through the grid electrode to form a micro level focus in the anode. A feed through applies a voltage to the cathode, the grid electrode and the electron focusing lens.