54results about How to "Reduce output frequency" patented technology

The present invention relates to a calibrated phase-locked loop (PLL), which has a calibration mode for measuring a tuning gain of a variable frequency oscillator (VFO) and a PLL mode for normal operation. Calibration information based on the tuning gain is used during the PLL mode to regulate a PLL loop gain. During the calibration mode, the calibrated PLL operates as a frequency-locked loop (FLL) for low frequency lock times, and during the PLL mode the calibrated PLL operates as a PLL for high frequency accuracy and low noise. By regulating the PLL loop gain, the desired noise spectrum and dynamic behavior of the PLL may be maintained in spite of variations in the operating characteristics or in the characteristics of the PLL components.

Provided are a method for compensating instantaneous power failure in medium voltage inverter and a medium voltage inverter system by using the same, the method for compensating instantaneous power failure in medium voltage inverter including a plurality of power cells supplying a phase voltage to a motor by being connected to the motor in series, the method including decreasing an output frequency of the plurality of power cells by as much as a predetermined value at a relevant point where an input voltage of the plurality of power cells is less than a reference value, decreasing the output frequency at a predetermined deceleration gradient, and maintaining the output frequency during restoration of input voltage as long as a predetermined time, in a case the input voltage is restored.

The invention discloses a vehicle-mounted composite power supply system of an electric vehicle and a control method. Through a voltage and current acquisition circuit, a voltage value and a current value of a motor inverter end, and voltage values of a battery set and a supercapacitor are obtained, and the processed to obtain required power, battery set SOC and supercapacitor SOC, which are used as decision-making input variables of a fuzzy logic control module. According to actual operation working conditions of the electric vehicle, a proper logic threshold value control strategy is formulated and by use of fuzzy control, fuzzification is performed on fixed rule parameters in a logic threshold, so rules are further refined, control thinking is further precise and results are further optimized. Compared with real-time power, the peak value of actual average power and the switching frequency are greatly reduced. By combining the power hysteresis control, the switching frequency of working modes of the system and the output frequency of the battery set are further improved, energy loss, caused by mode switching, of a vehicle-mounted double-energy system is reduced, service lifetime of the battery set is prolonged and efficiency and stability of the system are improved.

Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

The invention belongs to the field of radar microwave transceiving, and especially relates to a transceiver system implementation method for implementing digital phase shift and calibration with a DDS(Direct Digital Synthesizer) as a local oscillator. The DDS generates four paths of outputs to each path of T / R channel used as a third local oscillator; a waveform generation plug-in of a radar frequency source extension generates an intermediate frequency waveform and then the intermediate frequency waveform is provided to eight four-channel T / R components through an eight-way power divider; afirst local oscillator and a second local oscillator generated by the radar frequency source extension are sent to eight four-channel T / R components through the eight-way power divider; a single DDS processing module can carry out phase shift on four transmitting channels at the same time; and when a radar works in a transmission calibration mode, a calibration plug-in receives and processes signals sent by a calibration network and converts the signals into optical fiber signals to be output. The transceiver system implementation method for implementing the digital phase shift and calibrationwith the DDS as the local oscillator provided by the invention fully utilizes the advantages that DDS phase shift is simple and feasible, large in number of bits, high in precision, lower in price, small in size, multiple in channels and the like, and overcomes the problems that a traditional digital phase shifter is high in price, limited in the number of bits, low in integration level, large inweight and each channel needs a phase shifter.

The invention discloses a device and a method for controlling the precision of automatic preparation of an emulsion. The device comprises a variable frequency motor driving oil pump, and the oil outlet of the oil pump and the liquid outlet end of a water supply pipeline are respectively connected with two liquid inlets of a mixer; the liquid outlet of the mixer is connected with an emulsion tank;an oil supply pipeline is sequentially serially connected with an oil way solenoid valve and an emulsion flow meter; the water supply pipeline is sequentially serially connected with a water adding solenoid valve and a water adding flow meter; the emulsion tank is provided with a liquid level detector; a controller is respectively connected with the emulsion flow meter, the oil way solenoid valve,the water adding flow meter, the liquid level detector and the water adding solenoid valve; and a variable frequency motor is connected with the controller through a PID adjusting module. The methodcomprises the following steps: setting of basic parameters; collection of real-time data; starting of the preparation of the emulsion; quick tracking of preset values; and stopping of the preparationof the emulsion. The device and the method have the advantages of accurateness in metering of a mass ratio of water to the emulsion, improvement of the preparation precision of the emulsion, and realization of real-time control the concentration of the added emulsion.

The invention discloses a starting device of a brushless doubly-fed machine, and relates to the technical field of brushless doubly-fed machines. The direct-current output of a frequency converter is disconnected, and then switch tubes VT1, VT3, VT5 of an upper bridge arm and switch tubes VT2, VT4, VT6 of a lower bridge arm of a three-phase full bridge inversion circuit VI are disconnected at the same time, so that a brake resistor R0 is connected to a control winding PC, resources of the frequency converter can be sufficiently utilized, namely a starting resistor does not need to be used, the control winding PC can be in short connection by controlling full-controlled switch tube devices of the inversion circuit through software, the volume of the equipment can be reduced, and the cost is reduced.

The invention discloses a control method of a frequency converter and a control device. The control method of the frequency converter comprises the following steps of when an output frequency of the frequency converter is higher than a preset minimum frequency, beginning to detect an output current of the frequency converter; if the output current of the frequency converter is detected to be greater than a preset current, beginning to carry out timekeeping; when timing time is greater than preset overcurrent delay time, reducing the output frequency of the frequency converter. The invention also provides a corresponding control device of the frequency converter. When the output current of the frequency converter is too large, the output frequency of the frequency converter is reduced to a reference frequency. A slip frequency of the frequency converter and a motor is reduced so as to decrease the output current of the frequency converter. A circuit fault phenomenon caused by an overcurrent is prevented. Therefore, shutdown times of the device because of the overcurrent can be reduced and problems of resource and time wastes caused by repeated shutdown are solved.

A digital polar modulator (DPM) for transforming a baseband signal into a modulated digital modulator output signal comprises an input unit and two low-pass delta-sigma modulators, a first one being connected downstream from the first input part and configured to provide at its output a first pulse train in dependence on an amplitude- modulating baseband signal component, and a second one being connected downstream from the second input part and configured to provide at its output a multilevel quantized signal in dependence on a phase modulating baseband signal component; a multiphase generator, which is configured to provide a set of square-wave carrier signals having a common carrier frequency and exhibiting discrete phase shifts with respect to each other; a multiplexer, which is configured to provide a multiplexer output signal that is formed by switching, in dependence on a signal received at a select input as a function of time, between selected ones of the carrier signals; and a combiner unit.

Provided are a phase locked loop (PLL) apparatus and an operating method of the PLL apparatus including a PLL unit to provide a fixed frequency signal, a converter to convert, using the fixed frequency signal, a frequency of a first signal oscillated by a first voltage-controlled oscillator (VCO) based on a first control voltage, a first frequency divider to divide the converted frequency of the first signal, and a first phase comparator to compare the divided frequency of the first signal to an input first reference frequency and detect a first phase difference, wherein the first VCO may adjust the first control voltage based on the detected first phase difference to equalize the divided frequency of the first signal to the first reference frequency.

Disclosed is a method for controlling overcurrent jump stop of a high-temperature fan in a cement rotary kiln production line pipeline. The method includes detecting two-phase current of a high-temperature motor through a current sensor, and decomposing detected current through coordinate conversion to acquire momentary active and momentary reactive current; utilizing a PI adjuster to control the momentary reactive current to prevent a frequency changer from overcurrent protection due to load changing; when amplitude of output current of the high-temperature motor is higher than a set value, controlling the frequency changer to quickly lower frequency, and when current returns to normal, increasing the frequency to given frequency. The method has the advantages of simple principle, convenience in control, good reliability, high controlling accuracy and the like.

The invention provides a starting structure and a starting method for a brushless double-feed motor, and relates to the technical field of brushless double-feed motors. The starting structure comprises a converter, wherein output of the converter is connected with a control winding P<c> of the brushless double-feed motor; and a power winding P of the brushless double-feed motor is connected to a fundamental frequency power supply through a third switch KM3. According to the starting structure, by a PWM (pulse width modulation) converter, a short circuit device for shorting the power winding P is connected with the power winding and is matched with software control, so that the converter provided by the invention reduces a starting current without a brake circuit or a frequency-sensitive rheostat (or an adjustable resistor), and shorts the control winding P<c> without a starting resistor; only one short circuit device needs to add in hardware structure; low-current and low-cost soft starting of the brushless double-feed motor can be achieved by matching the starting method; the starting structure of the brushless double-feed motor is simple in structure; and the equipment volume can be reduced.

An improved light to frequency converter optical sensor and method using electronic bias. Adjustable gain also may be provided. A summing circuit sums electrical current from a photo detector and electrical current from a bias current circuit and provides the summed current to an integrator. A threshold detector comparator circuit has an input coupled to the output of the integrator and an output providing a series of pulses. The series of pulses has a frequency based on the light received by the photo detector and the electrical current from the bias current circuit.

An improved digital phase detector is provided for detecting and compensating for a cycle slip between a reference signal and a frequency source signal, the reference and frequency source signals each comprising pulses, each pulse defined by a leading edge and a trailing edge. The digital phase detector includes a detector circuit for detecting a cycle slip where two successive leading edges of one of the reference and frequency source signals are received before a leading edge of the other signal is received. An output circuit is operatively coupled to the detector circuit for developing a correction signal responsive to said detecting.

The invention provides a motor deceleration control method by an inverter. Multiple sub processes with the same processing flow are adopted to adjust the deceleration time repeatedly, and as for two adjacent sub processes, the deceleration time of a next sub process is adjusted according to the processing result of a former sub process. Each sub process comprises steps: the current operating parameters of the motor, the corresponding parameters of a DC bus of the inverter and the limiting values of the corresponding parameters of the DC bus are acquired; according to the difference between thecurrent operating parameters of the motor or the corresponding parameters of the DC bus and the limiting values of the corresponding parameters of the DC bus, PID control operation is carried out toobtain an adjustment amount; the deceleration time of the current sub process is calculated; and according to the deceleration time, the output frequency of the inverter in the current sub process iscalculated, and motor deceleration is controlled according to the output frequency. Thus, quick motor deceleration can be achieved while no brake resistor needs to be mounted.

The invention discloses a digital dimming control method using a PID algorithm. The method comprises a first step of initializing a program, and setting an initial setting value (power constant value) and an upper limit and a lower limit of a target value, wherein the upper limit and the lower limit are respectively X and Y; a second step of receiving an external constant power sampling value Next_Point, and calculating a current difference ek_0 between a setting value MB and the sampling value, that is, ek_0=MB-Next_Point; a third step of calculating a target value increment so as to obtain an amount of increase or decrease Udk of a target value, adjusting the target value according to the PID algorithm so as to obtain a target value Uk after PID adjustment; a fourth step of exchanging the setting value and a sampling difference; and a fifth step of comparing the target value with a set threshold, and finally returning the target value undergone PID adjustment to a master program to change an output frequency. The method has the beneficial effects that output frequency adjustment is changed and the power is stabilized by using a PID algorithm formula; if a feedback voltage is high, the output frequency is increased, if the feedback voltage is low, the output frequency is decreased; and the power is output steadily through sampling and high-speed cycling of PID calculation.

The invention discloses an inductive plumb coordinator, which is characterized by comprising an inductor fixed on a plumb body. The inductor has a hollowly cylindrical insular carrier and a magnetic material fixed with the same; the magnetic material is uniformly distributed around the central line of the hollowly cylindrical insular carrier; the inductor is sleeved outside the plumb body; the two sides in X direction and the two sides in Y direction of the inductor are provided with a pair of coils respectively; the coils on the two sides in X direction of the inductor are connected with a signal converter in X direction, while the coils on two sides of Y direction are connected to a signal converter in Y direction. The inductive plumb coordinator of the invention has the advantages of ingenious design, high measuring precision and relatively strong resistance to environmental interference; the inductive plumb coordinator is suitable for various severe environments and particularly is capable of reliably monitoring the dam displacement for a long time in humid, water-dropping and dusty environments and the like. The inductive plumb coordinator is expected to be popular and have a good market prospect after being launched.

The invention provides a multi-point vibrating blood activating device. The device comprises a total controller, vibrating elements and a connecting carrier, wherein each to-be-fixed vibrating elementis arranged on a corresponding part of the human body through the connecting carrier; any one vibrating element is internally provided with a compound component which forms a single vibration wave into a compound vibration wave, the transmitting directions of the vibration waves generated by all vibrating elements make the flow direction of qi and blood in the whole body of the human body consistent with the traditional running direction of qi and blood of the large circle of vital energy; and the total controller is in wireless communication with each vibrating element. The invention furtherprovides a multi-point vibrating blood activating method. The qi and blood circulation is promoted after vibrating massage, and then manual rubbing dredges muscles and bones auxiliarily. The multi-point vibrating blood activating device solves the problem of expedite qi and blood circulation fundamentally, so that the human body is in a good healthy state.

The invention relates to a high-precision temperature control method, a storage medium and a control device. The high-precision temperature control method comprises the steps that 1, a preset temperature T0 in a temperature adjusting space is determined, a return difference is set to be delta T, the upper limit of the temperature is set to be Tmax, the lower limit of the temperature is set to be Tmin, the real-time output frequency in the latest time period is calculated so that an output frequency average value F1 is obtained, and a compressor continuously operates under the output frequencyaverage value F1, 2, the real-time average temperature is compared with the temperature upper limit Tmax, if the real-time average temperature is larger than the temperature upper limit Tmax, the output frequency of the compressor is increased according to a set level so as to increase the refrigerating capacity, and if the real-time average temperature is smaller than the temperature lower limitTmin, the output frequency of the compressor is reduced according to the set level so as to reduce the refrigerating capacity. On the basis of continuous cooling and level adjustment modes, overall continuous cooling and cooling adjustment of the refrigeration space can be achieved, and the uniformity of the temperature in the refrigeration space is guaranteed.

A radio communication system for transmitting a radio signal with a transmission format in which a channel response calculation preamble signal serving as a reference upon reception is inserted is disclosed. The output frequency of channel response calculation preamble signals is varied in accordance with a temporal change in radio propagation environment. A channel response variation measurement unit measures a variation of the radio propagation environment. A channel response calculation preamble signal output frequency setting unit sets the output frequency of preamble signals in accordance with the temporal change in radio propagation environment. The preamble signals are inserted in the transmission format to be transmitted at that frequency.

The invention discloses a completely distributed collaborative optimization method for a multi-source energy storage type micro-grid. The method comprises the steps of 1) obtaining data, including related parameters of micro-grid equipment, and collecting new energy and load data; 2) in combination with the acquired data, establishing a game mapping model of micro-grid individuals, namely players; and 3) on the basis of micro-grid individual modeling, establishing an interactive game model among micro-grid individuals by adopting a potential game method to realize local and overall economic optimization of the micro-grid. According to the method, a completely distributed multi-subject decision optimization mode is adopted, and the conditional value-at-risk model and the generalized energy storage model are combined, so that local decision and management of micro-grid individuals are realized, income fluctuation caused by wind and light output uncertainty is effectively avoided, the consumption level of new energy is improved, and meanwhile, the individual benefits of the micro-grid can be ensured and the overall benefits of the micro-grid can be maximized by adopting a potential game mode.

The invention belongs to the technical field of cranes, and discloses a crane operation mechanism rail gnawing prevention device, a crane operation mechanism rail gnawing prevention deviation rectification control system, and a crane operation mechanism rail gnawing prevention deviation rectification control method. A plurality of first displacement sensors and a plurality of second displacement sensors are connected with a computer, the deflection angle of a crane frame relative to a rail is measured out by the displacement sensors, and then the deflection angle is converted into control voltage via proportional conversion through the computer; the control voltage is correspondingly added on first frequency converters and second frequency converters by a differential-action mode or a single-action mode, the first frequency converters and the second frequency converters are correspondingly connected with first control motors and second control motors, and the first control motors and the second control motors correspondingly adjust the stroke speed of a first driving wheel and the stroke speed of a second driving wheel. Rail gnawing between the inner side of a wheel flange of a wheel of an operation mechanism and the steel rail is effectively avoided, the stability of the crane in the operation process is enhanced, the operation side friction resistance of the crane is reduced,and friction noises between the wheel and the rail are reduced. Simultaneously, great potential safety hazards brought by the rail gnawing are eliminated, and safe operation of crane equipment and people safety are effectively ensured.

A signal generator includes a main ring oscillator and a first ring oscillator. The main ring oscillator is supplied by a power voltage, and is configured to generate an output oscillation signal. The main ring oscillator is coupled through a power mesh to the power voltage. The first ring oscillator is supplied by the power voltage. The first ring oscillator is similar or identical to the main ring oscillator. The first ring oscillator is coupled through the power mesh to the power voltage. The first ring oscillator is used to calibrate a frequency of the output oscillation signal.

A harmonic rejection mixer for carrying out a frequency translation of a mixer input signal having a mixer input frequency, the mixer including an up-conversion mixer for generating an intermediate signal by multiplying the mixer input signal with a first local oscillation signal having a first local oscillation frequency, and a down-conversion mixer for generating a mixer output signal by multiplying the intermediate signal with a second local oscillation signal having a second local oscillation frequency. The first local oscillation frequency and the second local oscillation frequency are greater than the mixer input frequency. The first local oscillation signal is an l-time oversampled sine wave and the second local oscillation signal is an m-time oversampled sine wave.

The invention discloses a liquid bottle liquid quantity detection system applicable to a chemiluminescence immunoanalyzer and an application method of the liquid bottle liquid quantity detection system. Liquid quantity detection in a container can be conducted based on a capacitance detection principle, a probe coated with a ceramic material is assembled in a substrate bottle as an electrode, a metal plate is installed at the bottom of the bottle as the other electrode, the electrodes are connected to a voltage-controlled oscillator as oscillator capacitance input, the output end of the voltage-controlled oscillator is connected with a schmitt trigger to shape the waveform of a capacitance change signal, the shaped waveform is taken as a timer external clock source, and by calculating a timer value per unit time, a pulse frequency per unit time is calculated; the pulse frequencies in the liquid and liquid-free states are calculated, and then the reasonable frequency can be selected asa judgment threshold; and later, when the frequency exceeds the threshold, no liquid in the container is determined, the corresponding alarming prompting and other processes are executed, the condition of inadequate monitoring of the liquid quantity state of substrate liquid is avoided, and the accuracy of test results is ensured.

The invention discloses a novel millimeter wave sub-sampling DDS frequency mixing fractional frequency division phase-locked loop structure. The structure comprises a buffer, a first sub-sampling phase discriminator PD1, a second sub-sampling phase discriminator PD2, a DDS, a DAC, a multiplier, a voltage and current conversion circuit, a low-pass filter, a first inverter chain F1, a second inverter chain F2, a frequency divider and a voltage-controlled oscillator. Frequency mixing is carried out after sampling output, the required DDS output frequency is greatly reduced, and good linearity andlow power consumption can be achieved while the power consumption is reduced. The structure has the characteristics that the high-resolution characteristic of the DDS output signal frequency is not influenced by a phase-locked loop, the phase-locked loop enables a frequency synthesizer to jump in a wide frequency range in a minimum frequency stepping manner, and the DDS provides the capability ofjumping in a narrow frequency range in a very small frequency stepping manner. Therefore, the broadband frequency conversion speed depends on the loop locking time of the phase-locked loop, and the narrowband frequency conversion speed after loop locking depends on the frequency conversion time of the DDS.