660 results about "Power difference" patented technology

In a radio communication system which uses pilot signals during transmission from a user terminal to a base station, the base station creates and stores a rank table on a peak to average power ratio of each pilot pattern, extracts a transmission power of the user terminal or a power difference between a maximum transmission power and the transmission power of the user terminal on the basis of a receive signal from the user terminal, and allocates a pilot pattern of which peak to average power ratio is good to a user terminal of which transmission power is great, or the power difference is small, with reference to the rank table.

Or a pilot pattern in a rank according to the transmission status (e.g. transmission power, distance from the base station) of the user terminal is adaptively allocated to the user terminal.

The present invention relates to a photovoltaic three phase synchronization control method realizing maximum power tracking swiftly and stably, which belongs to the technical field photovoltaic power generating control. The method includes the steps as follows: judging the DeltaP/DeltaV value according to the power difference DeltaP between the current time k and the previous time and the voltage difference DeltaV; working out the Iref(k) when the photovoltaic array produces the maximum power; using the Iref(k) to adjust the uq* under the coordinates in vectorial synchronous rotation with the electric network voltage; acquiring six ways of space vectorial SVPWM impulse series according to the rotation angle degree Theta of the three phase electric network voltage, with the aim to control the inverter in order to ensure that the output current of the photovoltaic inverter has the same phase position as that of the mains voltage while ensuring the photovoltaic array is realizing the maximum power output tracking. The power factor is 1. The present invention also can adjust the Idref(k) according to local load requirements, therefore achieving adjustment to the power factor, with low synchronization current harmonic wave distortion factor.

An RF switch is used in the signal path to an amplifier, for example between a receiving antenna and an amplifier. The switch is used to alternately connect the amplifier between a normal signal source for the amplifier and a fixed load for calibration. The power difference between the two switch states at the output of the amplifier would then yield a calibrated measurement of a signal value, such as rise over thermal (RoT). The amount of time spent in the calibration position is maintained at a minimized level so as to reduce impact on the normal operation of the amplifier. The invention provides an ability to estimate traffic load in a repeater system based on RoT measurements of repeater reverse-link output power by determining a reverse link gain.

The present invention concerns a digital imbalance correction device, comprising input means adapted to receive first input signals I-in, Q-in containing a plurality of channels from an I/Q converter stage at respective input terminals, each input terminal being associated to a respective signal branch, a time-to-frequency-domain-transforming means FFT adapted to perform a transformation of said first input signals from time-domain into frequency-domain, the transformation result being represented as a power spectrum of said respective first input signals, a subtracting means arranged to receive at its inputs second input signals which are represented by the power spectra of said respective transformed first input signals and to output the gain difference as a function of frequency at its output, a cross-correlation means arranged to receive at its inputs third input signals based on said input signals, and to output a cross-correlation of said third input signals, said cross-correlation output being proportional to a phase error between said respective correlation input signals, a gain correction means arranged in one of said respective signal branches and receiving at its input a fourth input signal based said associated first input signal, wherein a gain of said fourth input signal is corrected based on said power difference spectrum such that said gain of said fourth input signal equals the gain of the other one of said first input signals, and a phase correction means arranged in one of said respective signal branches and receiving at its input a fifth input signal based said associated first input signal, wherein a phase of said fifth input signal is corrected based on said cross-correlation output, such that said phase of said fifth input signal is in quadrature relation to the other one of said first input signals. The present invention also concerns a corresponding method.

The invention discloses a mode selection and resource allocation method for device-to-device (D2D) users in a cellular system, which reduces the algorithm complexity of the mode selection and resource allocation for the D2D users, and the obtained mode selection and resource allocation for the D2D users can reduce the transmission power needed by the D2D users. The method comprises two steps of mode and resource demand calculation and analysis and relevant algorithm for the resource demand and supply relation. The mode and resource demand calculation step comprises the following steps of calculating the minimal transmission power needed by each pair of D2D users under a cellular mode, a special channel mode and a multiplying channel mode; calculating the power difference of the D2D users under the three different modes; calculating the mode demand and the resource demand of each pair of D2D users; and counting the sum of the resource demand of the system. The analysis and relevant algorithm step for the resource demand and supply relation comprises the steps of further obtaining a mode selection and resource allocation algorithm under each situation according to the resource demand and supply relation of the system.

Power control methods and apparatus for use in a sectorized cell of an OFDM communications system are described. Each sector of a cell uses the same frequencies and transmission times and is synchronized with the other sectors in the cell in terms of tone frequencies used at any given time and symbol transmission times. Tones are allocated to channels in each cell in the same manner so that each channel in a sector has a corresponding channel in another sector. Power differences between channels in different sectors are maintained to be within a pre-selected power difference. Different channels in a cell are assigned different power levels. Wireless terminals are assigned to channels based on channel feedback information. Wireless terminals with poor channel conditions are allocated to higher power channels than wireless terminals with good channel conditions. Lower power channels often include more tones per symbol time than high power channels.

A method for determining direction of transmission using an antenna array having a number of panels is disclosed. Each panel is configured to receive signals. According to one aspect of the method, each of the panels is directed to receive signals from a transmitting node. For each panel, a first table having data representing received signal power difference between the panel and a first neighboring panel and a second table having data representing received signal power difference between the panel and a second neighboring panel are built. The panel with the maximum received power is identified. For the identified panel, a first gain table and a second gain table corresponding to its first and second neighboring panels are searched to identify a first transmission angle and a second transmission angle, if any. A transmission angle relative to the transmitting node is determined using the first and second transmission angles.

A multifocal ophthalmic lens, including: a far zone for correcting a far vision; and a near zone for correcting a near vision, arranged concentrically in an optical region of the lens, wherein a power distribution is set to vary progressively in radial direction of the far zone and the near zone; power is altered discontinuously to have a stepwise power difference at a boundary between the far zone and the near zone, the value of the power difference at the boundary between the far zone and the near zone is not greater than a maximum value of an intermediate power for correcting an intermediate vision.

The invention discloses an inertial frequency-modulation drive rotating speed protection control system and method for a doubly-fed wind turbine. A wind speed detection module collects the wind speed, the rotating speed of a fan and the pitch angle parameter. According to a rotating speed protection control link, the real-time captured mechanical wind power of the fan is computed according to information collected by the wind speed detection module, and a loss computing module is connected with the rotating speed protection control link, the loss is subtracted from the real-time captured mechanical wind power; and the obtained computing result is compared with electromagnetic power output by a generator, an input and output power difference caused when the doubly-fed wind turbine participates in system frequency modulation is obtained, the input and output power difference is transmitted to a proportional link and an integration link through a trigger switch, the negative feedback power control quantity is output after the proportional link and the integration link act, and the negative feedback control quantity and an inertial frequency-modulation control signal jointly serve as a frequency modulation additional active power given value. By means of the inertial frequency-modulation drive rotating speed protection control system and method, secondary impact on the system frequency when the doubly-fed wind turbine exits from the frequency modulation can be avoided, and the problem that the power loss is large due to that fact that the rotating speed in the constant rotating speed region is overly lowered is solved.

The invention relates to a virtual controller of electromechanical characteristics for a static power converter that includes a PLC (23) (power loop controller), which receives, at the input thereof, the power difference (ΔP) between the input power (P_in) (power delivered to the converter by the primary source) and the power delivered to the grid (P_elec) and is able to modify online the parameters of the virtual inertia coefficient and the damping factor as a function of the desired response and of the grid conditions for different frequency ranges.

The invention provides a segmentation self-adapting hill climbing method and a system thereof applied for tracing maximum power of a photovoltaic cell. The method comprises: finding the zone of the current power by partitioning the output power of the photovoltaic cell and comparing power difference of two adjacent moments with a set value; then, adjusting duty cycle to measure the power of the next moment until the maximum power point is found. The system of the invention comprises a photovoltaic cell, a DC/DC converter and a plumbic acid storage battery which are connected by circuits in sequence, wherein, a circuit between the DC/DC converter and the plumbic acid storage battery is provided with a voltage detecting module and a current detecting module, the output ends of the voltage detecting module and the current detecting module are respectively connected with a microprocessor, and the output end of the microprocessor is connected with the DC/DC converter via an isolation/ driving circuit. The invention quickens the tracing speed of the maximum power point, improves the anti-interference performance of the system, quickens the self-optimizing process of the maximum power point of the system and decreases the oscillation of the system at the maximum power point.

Power control methods and apparatus for use in a sectorized cell of an OFDM communications system are described. Each sector of a cell uses the same frequencies and transmission times and is synchronized with the other sectors in the cell in terms of tone frequencies used at any given time and symbol transmission times. Tones are allocated to channels in each cell in the same manner so that each channel in a sector has a corresponding channel in another sector. Power differences between channels in different sectors are maintained to be within a pre-selected power difference. Different channels in a cell are assigned different power levels. Wireless terminals are assigned to channels based on channel feedback information. Wireless terminals with poor channel conditions are allocated to higher power channels than wireless terminals with good channel conditions. Lower power channels often include more tones per symbol time than high power channels.

An average power value of a peak pair corresponding to a subjective target objective is converted into a radar cross section, to calculate a normalized average power value NP and a standard deviation DP representing a temporal dispersion of a power difference between peak pairs. When the value NP is larger than an automotive vehicle discriminating threshold THnp, the attribute of the subjective target objective is set to “automotive vehicle.” When the value NP is not larger than the threshold THnp and the deviation DP is larger than a human objective discriminating threshold THdp, the attribute of the subjective target objective is set to “non-vehicle objective: human objective.” Furthermore, when the value NP is not larger than the threshold THnp and the deviation DP is not larger than the threshold THdp, the attribute of the subjective target objective is set to “non-vehicle objective: non-human.”

The invention discloses a method for controlling the balance of a direct current side of a cascaded grid-connected inverter based on zero sequence and negative sequence voltage injection. The method is based on the combination of zero sequence voltage and negative sequence voltage injection; and the method comprises the following steps of (1) integrally controlling the direct current voltage by using a control method of positive sequence current decoupling, and correcting the unbalance of the system on the basis of positive sequence decoupling, and decomposing network voltage and the positive and negative sequence of the current by using a second harmonic filtering method; and (2) controlling the phase balance of the direct current side, respectively calculating the zero sequence voltage component and the negative sequence voltage component needing injecting, starting the zero sequence voltage injection method under a normal condition, and using the negative sequence voltage injection method when the power difference of each phase is large according to switching conditions. Furthermore, when the zero sequence voltage injection is used, the condition that the maximum output phase voltage does not exceed the maximum value provided by the inverter needs to be satisfied. Through the method, three phases can be comprehensively combined; the voltage of different phase sequences can be injected under different conditions, the output performance and interphase power adjustment ability of the device are both considered; and for the application of three-phase cascaded grid-connected inverter matched renewable energy sources large-scale synchronization and large-scale energy storage, the method has an important value.

A method and system for a cellular mobile communication system (900) are provided. The location of a mobile communication unit (905) in the cellular wireless communications system (900) can be estimated from: a first estimate of position, based on received signal power difference for signals received by the mobile communication unit (905) from at least two base stations (910); and a second estimate of the position of the mobile communication unit (905), from further information. A likelihood function for each estimate is weighted. The weighted first and second likelihood functions are combined, and one or more locations are selected as the estimated location. Propagation model parameters may be iteratively updated and/or refined, using location estimates obtained for large numbers of calls in the cellular mobile communication system (900).

A charging apparatus with dynamical charging power is configured to charge an electric vehicle. The charging apparatus includes a main power conversion unit, an auxiliary power conversion unit, and a control unit. The main power conversion unit receives an AC power and converts the AC power into a main output power. The auxiliary power conversion unit receives an auxiliary DC power and converts the auxiliary DC power into an auxiliary output power. The control unit controls maximum output power of the main output power to be an upper-limit output power value. When a charging power value of charging the electric vehicle is greater than the upper-limit output power value, the control unit dynamically controls the auxiliary output power according to a power difference value between the charging power value and the upper-limit output power value.

A torque base control unit calculates target torque based on an accelerator position and engine speed. The control unit further executes calculation of target airflow rate, calculation of target intake pressure, and calculation of target boost pressure based on the target torque. Target throttle position is calculated based on the target airflow rate, target intake pressure, target boost pressure, actual boost pressure, and throttle passed intake temperature. An assist control unit calculates target turbine power based on the target airflow rate and the target boost pressure calculated by the torque base control unit and calculates actual turbine power based on exhaust information. Assist power of a motor attached to a turbocharger is calculated based on the power difference between the target turbine power and the actual turbine power.

An upper limit value setting unit of a control device conducts integration on the change in battery power, and determines whether the integrated value is lower than a preset first threshold value (negative value). When determination is made that the integrated value is lower than the first threshold value, and the battery power difference is lower than the second threshold value (negative value), the upper limit value setting unit sets Vup2 that is lower than the general Vup1 as the upper limit value of the inverter input voltage command.

The invention belongs to the technical field of air conditioner control, and provides an air conditioner and a detection control method and device for the abnormal coolant circulation of the air conditioner. The method comprises the steps of in the operation process of the air conditioner, obtaining corresponding rated input power from a preset correlated database according to outdoor environment temperature, indoor environment temperature, operation frequency of a compressor and the opening degree of an expansion valve, judging that the coolant circulation is abnormal when the difference between the current air conditioner input power and the rated input power is larger than a power difference reference value, recording the abnormal times, and restarting the compressor to drive the coolant circulation to restore normal after the compressor is stopped for certain time if the abnormal times do not achieve the preset continuous abnormal times; if the normal times achieve the preset continuous abnormal times, showing that the coolant circulation cannot be restored normal, controlling the air conditioner to be stopped to avoid the damage of the compressor, and sending an abnormal prompt to notify a user, thus solving the problem that the air conditioner compressor is damaged due to the fact that the expansion valve of an air conditioner outdoor unit is blocked by a coolant.

The present invention is summarized as a radio communication method including the steps of calculating a transmission power difference between a transmission power value of a first carrier and a transmission power value of a second carrier; determining whether or not the transmission power difference exceeds a threshold which indicates a maximum transmission power difference allowable between the first carrier and the second carrier; and decreasing a data rate for transmission via one of the first carrier and the second carrier that has the higher transmission power value when the transmission power difference exceeds the maximum transmission power difference.