Abstract:
PROBLEM TO BE SOLVED: To provide a transmission leak signal canceling apparatus for an RFID system in which a function for reading an RFID tag and an adjustment function of a leak signal canceling section for canceling a transmission leak signal are implemented independently of each other.SOLUTION: A transmission leak signal canceling apparatus for an RFID system includes a reader control section for sending a transmitting signal to an RFID tag, receiving a receiving signal transmitted from the RFID tag and reading tag information. The transmission leak signal canceling apparatus further includes: a leak signal canceling section which performs adjustment work for receiving a part of the transmitting signal and the receiving signal, generating a cancellation signal depending on an adjustment value for canceling the part of the transmitting signal and the transmission leak signal, and canceling the transmission leak signal contained in the receiving signal; and a controller section for continuously determining whether an RF environment in which the RFID tag is mounted is changed based on a strength of the receiving signal, and controlling operation of the leak signal canceling section in accordance with the change of the RF environment.
Abstract:
PROBLEM TO BE SOLVED: To prevent a hunting phenomenon in which a current swings greatly in an motor drive system.SOLUTION: The present invention is an output current distortion compensation device of an inverter including an inverter control section which generates a PWM signal for controlling a PWM voltage generating section. The inverter control section includes a first dead time compensation voltage generation section which generates a compensation voltage in accordance with an output current polarity of each phase of the inverter; and a second dead time compensation voltage generation section which generates a compensation voltage in accordance with an output current waveform of each phase of said inverter. A first dead time compensation voltage output from said first dead time compensation voltage generation section and a second dead time compensation voltage output from said second dead time compensation voltage generation section are added, and thereby, the final dead time compensation voltage is generated.
Abstract:
PROBLEM TO BE SOLVED: To provide a hybrid fault current limiter achieving a reduced manufacturing cost.SOLUTION: The hybrid fault current limiter includes: a switching unit opening a driving contact arranged on a track and transmitting a trip signal if a fault current is flowed at an electric power system; a semiconductor switching unit connected in series with the switching unit and configured to be turned off to limit the inflow of the fault current when the trip signal is received; and a breaking unit connected in parallel to the switching unit and the semiconductor switching unit and configured to cutoff the fault current detoured from the switching unit and the semiconductor switching unit. The hybrid fault current limiter can detect failure more rapidly to limit a fault current by applying an algorithm sensing the occurrence of the fault current and an algorithm limiting the fault current simultaneously.
Abstract:
PROBLEM TO BE SOLVED: To provide a mode switching device of a PID control unit for, when switching an operation mode of the PID control unit to a manual mode and an automatic mode, stably switching the mode by removing any impact generated due to the switching of the mode.SOLUTION: The mode switching device of a PID control unit comprises: a PID arithmetic part for performing the PID arithmetic operation of an automatic mode and a manual mode according to a manual mode switching signal and an automatic mode switching signal, and for generating a driving signal; a manual mode buffering part for, when the manual mode switching signal is generated, processing the driving signal generated by the PID arithmetic part, and for outputting the driving signal to a load driving machine; and a speed difference integration signal calculation part for, when an automatic mode switching signal is generated, analyzing the driving signal generated by the PID arithmetic part, and for outputting the driving signal to the PID arithmetic part.
Abstract:
PROBLEM TO BE SOLVED: To provide an RMS detector for directly computing a signal detected through an analog circuit to measure its RMS value, and a circuit breaker using the same.SOLUTION: An RMS detector according to the present invention includes: a plurality of voltage/current sensing units 100 configured to detect a voltage or current shaped analog signal for an arbitrary load; a plurality of square circuit units 200 configured to compute square functions, respectively, based on a voltage output from the plurality of voltage/current sensing units 100; a summing circuit unit 300 configured to sum a plurality of output voltages output from the plurality of square circuit units 200, respectively; and a root circuit unit 400 configured to compute an RMS value based on a voltage output from the summing circuit unit 300.
Abstract:
PROBLEM TO BE SOLVED: To provide a DC link capacitor assembly that is easy in coupling, efficient in space application, and superior in temperature characteristics.SOLUTION: A DC link capacitor assembly according to the present invention includes a DC link capacitor disposed in a housing. The housing includes a top surface, a bottom surface disposed spaced downward from the top surface, at least one side surface connecting the top surface to the bottom surface, an opening defined at a front side between the top surface and the bottom surface, and an external capacitor accommodation part disposed outside the side surface.
Abstract:
PROBLEM TO BE SOLVED: To provide a power control apparatus of a hybrid power system, which is capable of improving power quality and can respond to a sudden change in load demand power.SOLUTION: A power control apparatus 200 of the hybrid power system includes a power measurement part 210 for measuring output power of the power system and a control part 220 for controlling operation of a first power generation part 115 and a second power generation part 117 in the power system on the basis of a previously set control mode and measured output power. When an output of the second power generation part 117 is controlled so as to be switched from ON to OFF, the control part 220 controls an output voltage of the first power generation part 115 to a first offset voltage corresponding to the output of the second power generation part 117 during a first time period.