680 results about "Dc control" patented technology

A calibrated DC compensation system for a wireless communication device configured in a zero intermediate frequency (ZIF) architecture. The device includes a ZIF transceiver and a baseband processor, which further includes a calibrator that periodically performs a calibration procedure. The baseband processor includes gain control logic, DC control logic, a gain converter and the calibrator. The gain converter converts gain between the gain control logic and the DC control logic. The calibrator programs the gain converter with values determined during the calibration procedure. The gain converter may be a lookup table that stores gain conversion values based on measured gain of a baseband gain amplifier of the ZIF transceiver. The gain control logic may further include a gain adjust limiter that limits change of a gain adjust signal during operation based on a maximum limit or on one or more gain change limits. A second lookup table stores a plurality of DC adjust values, which are added during operation to further reduce DC offset. The calibration procedure includes sampling an output signal for each gain step of the baseband amplifier at two predetermined range values and corresponding DC offsets using successive approximation. The data is used to calculate gain, DC offset and DC differential values, which are used to determine the conversion values programmed into the lookup tables or the gain adjust limiter.

The invention discloses an intelligent charging system and charging method of a power car lithium battery pack. The system comprises a power-supply filter module, a PFC power factor correction module and a DC-DC module. The system is characterized in that the system also comprises a DC-DC driving module and a SCM control unit, wherein the SCM control unit is used to output two-channel PWM waveform, and the two-channel PWM waveform is amplified by the DC-DC driving module to control the on/off of an MOS tube in the DC-DC module, thus the DC-DC module is controlled to output voltage and current and the optimal charging curve is tracked. By using the intelligent charging method of the invention, the lithium battery pack with a certain capacity and voltage range can be automatically charged, and the automatic charging maintenance can be performed. The method uses the SCM to output PWM wave and control the DC-DC circuit, thus controlling the charging voltage and current without using the DC-DC control circuit and DA switching circuit, reducing the cost of charger and increasing the control precision.

A transistor biasing circuit is shown that utilizes a negative feedback loop control circuit to set the gate bias voltage in the output transistors of a power amplifier. This control circuit has a current sensor in series with the drain of the transistor, the current sensor output in turn feeding a dc signal into a dc amplifier, and the output of the dc amplifier driving a gate bias integrator which forms a dc control loop for maintaining the bias point. The output transistor is protected from excessive temperature and/or excessive power dissipation.

A contactless card including an antenna coil, a resonant capacitor coupled between both end terminals of the antenna, a plurality of capacitors coupled in parallel with the terminals of the antenna correspondingly through switches, a shunt transistor coupled between the terminals of the antenna, forming a bypassing current path, a rectifier coupled between the terminals of the antenna, generating a DC voltage, and a control circuit sensing the DC voltage and controlling a gate voltage of the shunt transistor and on/off conditions of the switches in accordance with the sensed DC voltage.

The invention relates to a DC-DC control method of a hybrid power vehicle, which is particularly applicable to the hybrid power vehicle with a motor being coaxially coupled with an engine in parallelism; an ISG motor is provided; according to the status of the ISG motor and under the working modes of the supplementary driving mode, the power generation mode, the renewable braking mode, the idle stopping mode and the traditional working mode, HCU judges that whether opens or closes DC-DC; when DC-DC is on, the electric current flows from a high-voltage network to a low-voltage network and at the same time the output voltage of DC-DC is adjusted; when DC-DC is off, the electric current stops flowing from the high-voltage network to the low-voltage network, and the power of the low-voltage network is supplied by a low-voltage battery. The invention improves the utilization efficiency of the electric power, resolves the problems of the traditional controlling method, and can facilitate more reasonable energy flow of the entire vehicle.

An apparatus for electronically controlling a quadrupole in a mass spectrometer, comprises radio frequency (RF) drive circuitry and direct current (DC) drive circuitry coupled to a quadrupole, an RF control loop associated with the RF drive circuitry, a DC control loop associated with the DC drive circuitry, and control loop circuitry associated with the DC control loop, the control loop circuitry configured to alter a response of the DC control loop during a settling time period of a step response such that ion transmission through the quadrupole is greater during the settling time than if the response of the DC control loop during the settling time is unaltered.

A power amplifier with stacked, serially connected, field effect transistors is described. DC control voltage inputs are fed to the gates of each transistor. Capacitors are coupled to the transistors. The inputs and the capacitors are controlled to minimize generation of non-linearities of each field effect transistor and/or to maximize cancellation of distortions between the field effect transistors of the power amplifier in order to improve linearity of the power amplifier output.

A code sequence is encoded using a code conversion table in which the parity of the code sequence varies until the code states become equal to each other. The code word assignment used in this code conversion table is such that the decoded code word constraint length is 3 blocks and q₀≠q₁ for an arbitrary information sequence is satisfied even if a DC control bit is inserted at any of the first and second bits of an information word. Code states s₀ and s₁ when information sequences d₀ and d₁ resulted from insertion of provisional DC control bits 1 and 0 inserted at the top of an information sequence “1, 1, 0, 0, 0, 1, 0” are encoded starting with a state 3 according to a predetermined code conversion table are equal to each other, namely, s₀=s₁=6, in a third block, and two's complement q₀ of a sum of code sequences c₀ up to a time when the code states are equal to each other is “0” while two's complement q₁ of a sum of code sequences c₁ up to that time is “1”. That is, the condition that q₀≠q₁ is met. The code sequence can be applied to a recorder/player or encoder.

The invention discloses a DC breaker topology structure and a DC control method and belongs to the field of power and electronic technologies. The DC breaker has a "T" type two-way symmetrical structure and comprises a first current path, a second current path and a third current path. A leading-out terminal a of the first current path is connected with an end of a DC power transmission and distribution system equivalent inductor L9. A middle leading-out terminal b of the first current path is connected with one parallel ends of the second current path and the third current path. A leading-out terminal c of the first current path is connected with a DC power transmission and distribution line. The other parallel ends of the second current path and the third current path are connected with the ground. The invention can effectively solve the problem of DC arc extinguishing, is flexible in structure and strong in expansibility, meets the requirements of current switching on, current switching off, voltage endurance, loss, energy absorption and the like under different voltage and current levels of the DC power transmission and distribution grid, and significantly reduces the equipment cost.

A novel semiconductor variable capacitor is presented. The semiconductor structure is simple and is based on a semiconductor variable MOS capacitor structure suitable for integrated circuits, which has at least three terminals, one of which is used to modulate the equivalent capacitor area of the MOS structure by increasing or decreasing its DC voltage with respect to another terminal of the device, in order to change the capacitance over a wide ranges of values. Furthermore, the present invention decouples the AC signal and the DC control voltage avoiding distortion and increasing the performance of the device, such as its control characteristic. The present invention is simple and only slightly dependent on the variations due to the fabrication process. It exhibits a high value of capacitance density and, if opportunely implemented, shows a linear dependence of the capacitance value with respect to the voltage of its control terminal.

The invention discloses a hybrid direct-current transmission system. A first group of thyristor converter units and a second group of thyristor converter units are connected with the same sending end alternating-current power grid through a converter respectively, or connected with different sending end alternating-current power grids. An inversion converter station is composed of at least one group of voltage source converters, direct-current lines at the positive and negative ends of each voltage source converter are respectively equipped with a first switching element and a fourth switching element, and the direct-current lines at the positive and negative ends are wired in parallel and in a cross manner to the opposite-end direct-current lines through the first switching element and the fourth switching element respectively. Converter stations at the two ends are connected by two direct-current lines. The invention further discloses a hybrid direct-current transmission system control method and a hybrid direct-current transmission system power reversal control method. The hybrid direct-current transmission system of the invention has the advantages of low cost of traditional direct current, flexible control on flexible direct current, and the like.

The invention discloses a control method for an electric automobile participating in grid frequency modulation based on V2G technology. A charge/discharge circuit is a two-stage converter circuit, which comprises a PWM rectification circuit and a matched LC filter and a Buck-Boost conversion circuit, wherein the two circuits are connected through a DC bus capacitor; the PWM rectification circuit rectifies a network voltage into a 700V DC voltage, AC-side harmonic waves are filtered through the LC filter, and the PWM rectification circuit is connected with a power grid through a network-side inductor; and the Buck-Boost conversion circuit converts the 700V DC voltage into a 60V DC voltage, and is connected with an electric automobile directly. The method adopts an AC/DC control module and a DC/DC control module, and meanwhile, enables a frequency modulation control module to be embedded into the DC/DC control module; and charge and discharge power reference values of a power battery are given through the frequency modulation control module, and a current transformer makes a response to realize primary and secondary frequency modulation of the power grid.

A transimpedance amplifier having open-loop DC control is provided. The open-loop feedback control may provide a DC bias that is configurable based on the characteristics of an input device, such as, a photodiode or a magnetoresistor. The open-loop feedback control may provide quick recovery from voltage level variations and may provide stability for the amplifier.

The invention relates to a direct-current controlling and protecting method for the ice-melting of an ultra high voltage direct current transmission line. For an once connection mode for the ice-melting of two parallel current converters, the control strategies and methods that two current converters at the rectification side are used for setting the electric current, and one of two current converters at the inversion side is used for setting the electric current, and the other one thereof is used for setting the voltage are adopted so as to ensure that an ultra high voltage direct current system can continuously and stably operates in an ice-melting operating mode. The currentration of each current converter at the rectification side is one half of the input ice-melting current instruction value and is one half of the currentration tracing line current measured value of the current converter used for setting the electric current at the inversion side, thereby the even distribution of the direct current between two current converters at the inversion side can be ensured, and the current converter used for setting the voltage at the inversion side is used for controlling the direct-current voltage of the parallel current converters.

The voltage-controlled oscillator (VCO) in a frequency synthesizer using a phase-locked loop (PLL) is calibrated digitally during power up. The VCO has a coarse frequency control and a fine frequency control. The coarse control is a digital phase-locked loop to quantize the broad frequency range into limited number of frequency steps with a clock frequency divided from the VCO frequency, and to hold the phase-locked dc control voltage for the fine control. By limiting the number of frequency steps and clocking at a divided frequency of the VCO, the coarse control is speeded up. The fine control is [connected to the charge pump output as in] a regular PLL. By searching for the optimal control setting, the center frequency of the VCO is trimmed close to the wanted frequency for the PLL to lock. This allows small VCO gain without losing the tolerance of process and temperature variations. As a result, the PLL phase noise performance is improved.

The invention discloses a multi-infeed extra-high voltage power grid transverter wattless configuration method based on a short-circuit ratio. The extra-high voltage power grid transverter wattless configuration method comprises steps of 1) determining an object grid structure to be analyzed and related parameters, 2) arranging operation modes of an electric power system, 3) selecting a specific operation mode to calculate system load flows under different DC control modes, 4) calculating a multi-infeed short circuit ratio according to a load flow calculation result, 5) calculating a multi-infeed DC node voltage comprehensive improvement index, 6) determining a candidate node of the multi-infeed extra-high voltage DC power grid transverter wattless configuration n according to the multi-infeed DC node comprehensive improvement index, and 7) programming a single objective function optimization program according to an objective function to determine a wattless compensation capacity. The extra-high voltage power grid transverter wattless configuration method guarantees to reduce the operation cost of the power grid, guarantee the power grid to safely, reliably, economically, and efficiently operate, has significance and provides technical basis to planning design and operation control of the mmulti-infeed high voltage DC power grid.

A novel semiconductor variable capacitor is presented. The semiconductor structure is simple and is based on a semiconductor variable MOS capacitor structure suitable for integrated circuits, which has at least three terminals, one of which is used to modulate the equivalent capacitor area of the MOS structure by increasing or decreasing its DC voltage with respect to another terminal of the device, in order to change the capacitance over a wide ranges of values. Furthermore, the present invention decouples the AC signal and the DC control voltage minimizing the distortion and increasing the performance of the device, such as its control characteristic. The present invention is simple and only slightly dependent on the variations due to the fabrication process. It exhibits a high value of capacitance density and, if opportunely implemented, shows a quasi linear dependence of the capacitance value with respect to the voltage of its control terminal.

The invention relates to a self-adaptive digital DC/DC control method which has fast dynamic response and a converter. The self-adaptive control method related by the invention is implemented in a secondary side controller. In the control method, error detected is positive (negative) when sag (uprush) happens to an output voltage, and a first PID with good steady-state characteristics is switched to a second PID with good dynamic characteristics when the absolute value of the error exceeds a preset threshold value, the output voltage begins to enter a steady state when the error turns to be negative (positive), and the second PID is switched to the first PID when alternative changes between positive and negative errors are continuously detected, for which a steady state is deemed to be realized. The circuit structure of the DC/DC converter comprises a main power topology, an isolating transformer, a primary side controller, the secondary side controller, a driving circuit, a voltage and current detecting channel, a feedback and sampling channel, a primary side assisting source, a secondary side assisting source, a parameter memorizer and a communication interface. The control method of the invention has reasonable design and the converter is simple and practical.

The invention is a high-voltage breaker synthetic tester for power system, combining operating program controller, high-power continuously adjustable DC power supply and minimum acting voltage tester of breaker together, and composed of master control board, high-power continuously adjustable DC power supply module, output control module, display and small keyboard, where the master control board is a MCU system composed of CPU and relative devices, responsible for control of the whole system work, the output control module has 4 I/O ports outputting control instruments to control switch-on and switch-off of the breaker switching-on and-off loop; the master control board controls 0-5V DC control voltage by a D/A converter in order to control output of 0-250V adjustable DC power supply, the output end of adjustable DC power supply is connected to the breaker switching-on and-off loop to act as a power supply of the loop; the master control board monitors the variation of the output DC voltage and the DC current in the output loop by an A/D converter.

The invention provides a bidirectional DC-DC control method for a hybrid power ship. According to the method, charge and discharge states of a marine lithium battery and charge and discharge current can be controlled by a bidirectional DC-DC converter, and energy distribution of the hybrid power ship can be more reasonable. The control method includes four mods and one state and includes automatic control, manual control and state transition. A control strategy includes that: when the operating modes are switched, a controller transmits a power request command to the bidirectional DC-DC converter so that the bidirectional DC-DC converter adjusts the output power in real time; when a hybrid power system operates, the output voltage of the bidirectional DC-DC converter is limited by direct-current bus voltage. The bidirectional DC-DC converter is provided with an RS485 interface and an analog and switching output interface, and the bidirectional DC-DC converter switches the operating modes under control of a PLC (programmable logic controller).

A wireless DC control device including a radio frequency transmitter, receiver, and switching circuit controls the current and polarity of the current that is used to power DC motors used in mobile living quarters. The control device has particular application for controlling the extension and retraction of slide-out rooms in a mobile living quarters.

The invention provides a method for tripping during re-unlocking frequency overlimit after temporary locking of a flexible DC control system. When an AC system of a connected variable network side is in a short-term failure, a valve control system judges bridge arm overcurrent, temporary locking of the valve control system is triggered and a pole control system is informed to lock, after bridge arm current gradually declines, the temporary locking state disappears and the pole control system is re-unlocked after a certain time delay. When the connected variable network side is in a serious failure, the valve control system and the pole control system can repeatedly be subjected to temporary locking and unlocking processes, and the pole control system achieves a locking tripping function when the unlocking frequency exceeds the limit. According to the method, the crossing success rate of the flexible DC control system in an AC failure is improved and primary equipment of a flexible DC converter valve is also protected.