摘要:
Disclosed is a lyocell multi-filament for a tire cord and a method of producing the same. The method includes i) dissolving mixed powder of cellulose and polyvinyl alcohol in a mixed solvent of N-methyl morpholine N-oxide and water to prepare a dope, ii) extruding the dope using a spinning nozzle including orifices through air gaps into a conical upper coagulation bath to solidify the dope to produce a multi-filament, iii) feeding the multi-filament through a lower coagulation bath to a washing bath, and washing the multi-filament, and iv) drying and oiling the washed multi-filament and winding the resulting multi-filament. At this time, the orifices each have a diameter (D) of 100 to 300 µm, a length (L) of 200 to 2400 µm, and a ratio of the length to the diameter (L/D) of 2 to 8, and are spaced apart from each other at intervals of 2.0 to 5.0 mm. The method provides a lyocell multi-filament having excellent physical properties useful as a tire cord, thereby producing a tire for an automobile having improved driving stability, dimensional stability, and uniformity using the tire cord.
摘要:
The present invention relates to a power management system (PMS) for multiple energy storage systems (ESS) that is for integrated management of the system having multiple ESS for controlling a frequency and having a hierarchical control structure. The PMS for ESS comprises: a plurality of ESS; a local management system (LMS) for managing one or more ESS of the plurality of ESS for each local unit; an ESS Controller (ESSC) for general management of the LMS, judging a state of the LMS and determining an output value of one or more ESS in the LMS, and transmitting the determined output value to the respective ESS; and a PMS for general management of the entire system comprising the plurality of ESS, the LMS and the ESSC, judging the state of the entire system and participating in a power grid frequency control market through a grid operator contract, controlling the output of the LMS, and adjusting a control parameter for output control.
摘要:
Disclosed is a high voltage DC circuit breaker that interrupts a fault current flowing through a high voltage DC transmission line with a vacuum circuit breaker and a gas circuit breaker connected in series. The circuit breaker includes: a vacuum circuit breaker installed on a DC transmission line and operating to interrupt a current in the DC transmission line when a fault occurs on either side of the DC transmission line; a gas circuit breaker connected in series with the vacuum interrupter; an LC circuit connected in parallel with the vacuum circuit breaker (110) and including a capacitor and a reactor connected in series to induce LC resonance; a first bidirectional switching device connected in series with the LC circuit and switching a current flowing in any of two opposite directions; and a second bidirectional switching device connected in parallel with the LC circuit and switching a current flow to induce LC resonance in two opposite directions.
摘要:
The present invention relates to a polyketone resin composition and a method for manufacturing the same. The polyketone resin composition is prepared by mixing a polyketone terpolymer consisting of repeating units, represented by the following general formulas (1) and (2), with ABS, a glass fiber, a sulfonamide-based plasticizer and a mineral filler, and is applicable to various industrial fields requiring oil resistance, calcium chloride resistance, impact resistance, etc.
摘要:
The present invention relates to a polyester tire cord with excellent dimensional stability which utilizes a yarn manufactured by adjusting spinning and drawing conditions, and a method for manufacturing the same.
摘要:
The present invention relates to a module extraction apparatus of a high voltage direct current system. In the present invention, a fixed base (30) is secured to a structure (82), and a sub-module (10) is mounted on a movable base (60) that slides on the fixed base (30), thereby enabling the sub-module (10) to be extracted from the structure (82). The sub-module (10) may be separated into a power unit (12) and a capacitor unit (24) which may be separately extracted from the structure (82). A connection support (84) is connected to the fixed base (30) and installed to protrude toward the outside of the structure (82), and the tip end of the connection support (84) extending toward the outside of the structure (82) is supported by a wire (86). As described above, the present invention has an advantage of more easily extracting the module, which is a heavy object, from the structure (82) to carry out the maintenance thereof.
摘要:
The present invention relates to a direct current (DC) circuit breaker using a magnetic field, for generating a magnetic flux in a direction vertical to the direction of an arc current generated in a main switch so as to increase resistance to the arc current and for continuously supplying a circulating current from a DC line so as to further increase the magnetic flux and thus continuously increase the resistance to the arc current, thereby extinguishing an arc. The DC circuit breaker using a magnetic field according to the present invention comprises: a main switch installed in a DC line; a coil wound so as to generate a magnetic flux in a direction vertical to the direction of an arc current generated when the main switch is opened; a semiconductor switch for switching current application to the coil; a capacitor connected in series to the semiconductor switch; and a first diode for conducting the electric current of the line, supplied from one side of the main switch, to the capacitor, wherein the semiconductor switch is turned on, in case a fault occurs, so that the electric current is applied to the coil by the voltage charged in the capacitor.
摘要:
The present invention relates to a ballistic cloth using a unidirectional aramid sheet and a polyethylene film and a method for manufacturing the same and, more particularly, is characterized in that aramid multifilament layers, which have monofilaments stacked and arranged in one direction, are arranged perpendicularly, a polyethylene film, which plays both the role of a binder and the role of protecting the sheet surface, is arranged between the aramid multifilament layers to manufacture a ply, and the ply is inserted into a mold and undergoes a pressing process and a cooling process, thereby manufacturing a ballistic cloth. A ballistic cloth manufactured by the method according to the present invention is advantageous in that use of a polyethylene film having a low softening point between unidirectional aramid sheets improves adhesiveness between the sheets and also improves the slip factor when the same ply is stacked, thereby exhibiting excellent ballistics performance. In addition, since the binder is solely made of a film, odor-free, environment-friendly manufacturing processes can be employed, no freezing is needed during storage; improved flexibility of the sheet facilitates delivery and distribution of impacts of bullets when the ballistic cloth is worn, thereby improving the ballistics performance and making the ballistic cloth further lightweight; and the polyethylene film, which is the protective layer of the unidirectional aramid sheets, has an adhesive strength of at least 2kgf, thereby improving the ballistics performance.
摘要:
The present invention relates to a converter for electric power having multiple sub-modules connected in series, the sub-modules having an energy storage unit and multiple power semiconductor circuits connected in parallel to the energy storage unit, and which causes an electric current to bypass a sub-module in case the breakdown of the sub-module occurs. To this end, the converter for electric power according to the present invention has multiple sub-modules connected to each other in series, the sub-modules having an energy storage unit and at least one power semiconductor circuit that is connected in parallel to the energy storage unit and comprises multiple power semiconductor switches and freewheeling diodes, wherein each of the sub-modules comprises a bypass switching unit, which is connected in parallel to any one of said at least one power semiconductor circuit, and bypasses an electric current via the bypass switching unit.