33results about How to "Accurate and reliable sampling" patented technology

An ultrasonic diagnostic apparatus includes an image creating unit (15) configured to create an image (26a) of an affected area (26) and an image (22a) of a puncture needle (22) inserted into a subject (P) by means of an ultrasonic scanning operation, and a monitor (4) configured to display the image (26a) of the affected area (26) and the image (22a) of the puncture needle (22) created by the image creating unit (15), wherein the image creating unit (15) displays a tissue expected to be extracted from the affected area (26) as an image on the monitor (4) before the puncture needle (22) is inserted into the affected area (26).

The invention provides an intelligent moulded case circuit breaker in allusion to the defect of the current moulded case circuit breaker. The intelligent moulded case circuit breaker is mainly composed of a controller module, a collecting module, a power module and a tripping module. The technical solution used for solving the technical problems comprises the steps: sensing a three-phase power supply circuit through a current transformer by the power module, and connecting a control circuit to control a capacitor to periodically charge / discharge after obtaining the induced current, and obtaining the output voltage; controlling the sampling frequency of the collecting module for the grid signal through the control circuit by the controller module; according to the collected grid data, outputting the logic level signal by the controller module, and controlling the action of the tripping module; and supplying the power to the tripping module and the controller module by the power module. The subsection sampling technology used by the intelligent moulded case circuit breaker is capable of accurately measuring the large signal and small signal at the same time, and improving the sampling precision. The current sampling loop uses the full-wave rectification, and the current generated by the transformer can supply the power to the communication module.

The invention discloses a generator power transmitting system and method. The system comprises a power transmitting device, a generator terminal protection-level current transformer TA, a generator terminal measuring-level current transformer and a generator terminal voltage transformer TV. The power transmitting device collects generator terminal three-phase voltages, generator terminal protection-level TA three-phase currents and generator terminal measuring-level TA three-phase currents through the voltage transformer and the current transformer. The fundamental wave effective values of positive sequence voltages, the positive sequence currents of the generator terminal protection-level TA, the positive sequence currents of the generator terminal measuring-level TA and the three-phase currents of the protection-level TA are calculated. When the fundamental wave effective value of the three-phase currents of the protection-level TA is larger than a switching threshold value Iset, power calculation currents are extracted from the protection-level TA, otherwise the power calculation currents are extracted from the measuring-level TA, and a power value is calculated through the positive sequence voltages and the power calculation positive sequence currents. According to the generator power transmitting system and method, generator power abnormal large fluctuation caused by incorrect action of a generator power automatic adjusting system during the system failure can be avoided.

The invention relates to an islanding detection circuit and detection control method for a microgrid power generation system. The detection circuit comprises a sampling circuit for sampling from a main power grid; the sampling circuit enables the sampling signal to pass through an isolating circuit, a filter circuit, a waveform conversion circuit and a photocoupling isolating circuit and then inputs the sampling signal to a DSP processor; after the sampling signal is processed by the DSP processor, a PWM signal is sent out from a PWM driver to drive an IGBT inverter; and the microgrid power generation equipment passes through the IGBT inverter, the filter circuit and a circuit breaker and then is connected to the main power grid. The invention relates to the islanding detection circuit and detection control method for the microgrid power generation system, and the islanding state can be detected in time and can be controlled.

The invention provides a frequency converter three-resistance current sampling method based on current prediction. In each PWM (Pulse-Width Modulation) period, current closed loop PID (Proportion Integration Differentiation) control and SVGEN modulation are performed, and PWM comparison values T<1>, T<2> and T<3> of three phases A, B and C are obtained; the sizes of the T<1>, the T<2> and the T<3> and the shortest time T<min> required by complete sampling are compared in real time; and different current obtaining modes are used according to different size relationships. The method provided by the invention solves the problem that the three-phase current cannot be accurately sampled due to zero-voltage vector duration insufficiency at a high modulation ratio of the conventional three-resistance sampling technology of a three-phase frequency converter. The wide region current closed loop control under the three-resistance sampling can be realized; the modulation ratio is improved; the motor load capability is improved; the cost is low; and the sampling is simple and reliable.

The invention discloses a fault protection device for monitoring the working condition of an ignition device of an engine, and aims at providing the fault protection device capable of effectively eliminating the interference of working circuits of the ignition device. The technical scheme of the fault protection device is as follows: in a data processing comparison control circuit, a sampling module is in series connection with a signal processing module and a data processing control module in proper sequence; the data processing control module is electrically connected to a display module and is electrically connected to a primary power supply end of the ignition device by a fault protection module; the sampling module performs signal sampling from a sampling interface of the ignition device; the signal processing module is used for carrying out compensation filtering on sampled signals and for feeding read current peak values into the data processing control module; and the data processing control module is used for carrying out data comparison, analysis and judgment on sampling frequency and / or the current peak values, for giving out a fault warning signal instruction to the display module, and meanwhile for controlling the fault protection module to disconnect a primary power supply of the ignition device, so that the device enters a fault locking state, and a starting switch loses efficacy.