173 results about "Delta-v" patented technology

A decoupled switched current temperature circuit with compounded DELTA Vbe includes an amplifier having an inverting input with corresponding non-inverting output and a non-inverting input with a corresponding inverting output; a PN junction connected to the non-inverting input through a first input capacitor and a voltage reference circuit is connected to the inverting input through a second input capacitor; a current supply includes a low current source and a high current source; a switching device applies the high current source to the PN junction and applies the low current source to the PN junction for providing the DELTA Vbe of the PN junction to the first capacitor; a first feedback capacitor is interconnected between the inverting output and the non-inverting input and a second feedback capacitor is interconnected between the non-inverting output and inverting input of the amplifier to define the gain on each of the inputs to produce a differential voltage across the outputs representative of the temperature of the PN junction; first and second reset switching devices discharge the first and second feedback capacitors, respectively, and a multi-phase switched device alternately interchanges the connection of the first and second input capacitors with the amplifier inputs for compounding the single DELTA Vbe .

The invention discloses a lithium secondary battery consistency screening method, belonging to the field of secondary batteries, characterized in that: a unit battery grades the capacity, platform, and internal resistance when conducting capacity grading and detection, and then the unit battery is charged by multi-step constant current and constant voltage, wherein a constant current of 0.3-5C5 is used for charging to a voltage V0, when the charging current is 0.1-0.3 C5, the charge is stopped and the battery is shelved; after the battery is shelved for 5-30 min, the charging is continued with a constant current of 0.1-0.3 C5 to the voltage V0, when the charging current is 0.05-0.1 C5, the charge is stopped and the battery is shelved; after the battery is shelved for 5-30 min, the charging is continued with a constant current of 0.05-0.1 C5 to the voltage V0, when the charging current is 0.03-0.05 C5, the charge is stopped and the battery is shelved; after the battery is shelved for 5-30 min, the charging is continued with a constant current of 0.03-0.05 C5 to the voltage V0, when the charging current is 0.01-0.03 C5, the charge is stopped; after the charging is complete, the unit battery is shelved at a normal temperature, the shelving time is no less than 24h, when the shelving ends, measurement is carried out on the open-circuit voltage Vt of the unit battery, if the open-circuit voltage Vt is no less than the result of V0 minus delta V0 and minus n*delta V, the unit battery is qualified. According to the invention, the qualified unit battery screened by the invention has low self-consuming hazards, the combined battery pack has good self-discharge consistency, high reliability, and rapidness, simpleness and easy operation in practical application, and has a good market application prospect.

The invention discloses a method for controlling the in-orbit autonomous shutdown of a spacecraft propulsion system, which comprises a pressure-speed shutdown control mode: in the process of performing orbit control, measuring the storage tank pressure P by a pressure sensor; determining the thrusting force coefficient k through an in-orbit calibration on the ground; calculating the speed increment delta-v generated in each software cycle delta-T for the propulsion system when a satellite receives an orbit control command sent from the ground, wherein delta-v=(F.delta-T)/m=(k.P.delta-T)/m; and accumulating the delta-v, and comparing the same with the 'speed increment' v in the ground orbit control command, wherein if the accumulated result of the delta-v is more than or equal to the 'speed increment' v in the ground orbit control command, the propulsion system is controlled to perform shutdown. The method uses two shutdown control modes of temperature-time and pressure-speed to solve the key problem of accurately performing starting up and shutdown by a novel self-pressurization liquefied gas propulsion system.

The invention discloses a fault detection method of a three-phase power supply. The fault detection method of the three-phase power supply includes the following steps: first, rectifying and filtering the three-phase power supply to direct current (DC) bus voltage; second, detecting the direct current (DC) bus voltage, working out ripple voltage delta V; then, judging whether the three-phase power supply is damaged according to the ripple voltage delta V. According to the detection method of the three-phase power supply, abnormal conditions of phase failure, phase voltage unbalance and momentary power failure of the three-phase power supply can be detected accurately, and high power loads which apply the three-phase power supply to supply electricity can be protected rapidly by the fault detection method of the three-phase power supply. If the fault detection method of the three-phase power supply is applied to power-supply protection design of frequency-converted loads, the frequency-converted loads and rectifying circuits and inverter circuits of drive circuit of loads can be protected effectively, probabilities of problems that damage in the frequency-converted loads, the rectifying circuits and the inverter circuits and the like caused by abnormity of power grids can be decreased, circuit design can be simplified and hardware cost can be reduced and reliability of products is enhanced at the same time.

The invention relates to a method for effectively screening self-discharging batteries. The method comprises the following steps: (1) determining low-voltage-state voltage knee points of batteries by using a trickle charge method; (2) carrying out charging and discharging on the batteries, allowing the voltage of the batteries to be finally located at the low-voltage-state voltage knee points, and after the voltage of the batteries tends to be stable, measuring and recording the voltage OCV1 of each battery; (3) storing the batteries at a set temperature for a period of time and measuring and recording the voltage OCV2 of each battery; and (4) calculating the voltage drop value delta V of each battery, wherein delta V satisfies the equation that delta V = OCV1 - OCV2, and if the voltage drop value delta V of a battery exceeds a set value, the battery is a self-discharging battery need to be screened out. The method provided by the invention is more scientific, accords with principles, can more accurately screen out self-discharging lithium ion batteries and reduces irreversible capacity loss of batteries in the phase of screening of self-discharge; thus, excellent electrochemical performance and safety performance of batteries in subsequent usage are guaranteed.

The invention relates to an interplanetary transfer orbit design method, in particular to a transfer orbit design method from a periodical orbit which is near dynamic balance points of a three-body system to a small celestial body and belongs to the technical field of aerospace. Firstly, based on the periodical orbit which is near the dynamic balance points of the three-body system where a detector is located, an initial state of the detector x0=[ r0, v0] is assumed. Secondly, a speed increment delta v is exerted along a tangential direction so that the detector sets off from the periodical orbit near the dynamic balance points. Based on a multiple-body model, relations between the detector and a distance df of the detector and the target small celestial body, a flying period tf and the tangential direction speed increment delta v are built up when the detector flies across the target small celestial body is built. Through an optimizing algorithm, an initial value of the transfer orbit is obtained when the fight distance df is minimum. Finally, a secondary-level differential correction method is used based on the initial value to obtain orbit parameters which can meet two point boundary values. The interplanetary transfer orbit design method can achieve rapid design of flight from the periodical orbit which is near the dynamic balance points of the three-body system to the small celestial body, calculation amount is small and efficiency is high.

The invention provides a method and device for tracking a maximum power point of a solar battery, wherein the method comprises the following steps: (a) detecting the current output voltage V1 and the current output current I1 of the solar battery, calculating the current output power P1, setting the voltage change step length Delta V and the preset voltage change step length Epsilon 1 of which the value is less than the voltage change step length Delta V; (b) respectively changing the output voltage into (V1-Delta V) and (V1+Delta V), respectively detecting the current Ia and Ic and calculating the output power Pa and Pc; and (c) comparing Pa, P1 and Pc and respectively executing different treatments according to the relationships among the Pa, P1 and Pc. In the method for tracking the maximum power point of the solar battery provided by the invention, a large step length at the primary period of searching is used, and the step length is reduced continuously to perform the searching by means of a three-point comparing method so as to accelerate the searching speed and avoid vibration and error judgment.

The invention provides a cruise control method and device of an electric vehicle. The cruise control method comprises the following steps of receiving a constant speed cruise request in accordance with the electric vehicle, wherein the request carries a cruise set vehicle speed v <stp>; calculating a difference value delta v between the cruise set vehicle speed v <stp> and a current vehicle speed v according to the formula delta v=v-v <stp>; calculating an average amending acceleration a <m> required by the vehicle in a preset amending cycle delta t according to the formula a <m> = delta v / delta t; and according to the average amending acceleration a <m>, calculating cruise requiring torque, and using the cruise requiring torque to drive the vehicle to travel. According to the cruise control method disclosed by the invention, in the cruise control process, the stability and the comfortableness of the electric vehicle are improved, and the constant speed cruise developing and calibrating working capacity is reduced, so that the constant speed cruise control of the electric vehicle is rapid in response and high in robustness.

Provided are thick, high tensile-strength hot-rolled steel sheets that have high strengths of TS: 521 MPa or higher and excellent low temperature toughness. Specifically, steel raw material is heated, and after hot-rolling that comprises roughing-down and finish rolling, cooling of 10 DEG C/s by mean cooling rate at the center of the sheet thickness is performed to below a specified end cooling temperature that is dependent on the amounts of alloy elements and the cooling rate. Then the steel is taken up at below a specified take-up temperature that is dependent on the amounts of alloy elements. It thereby becomes a thick hot-rolled steel sheet of excellent structural uniformity in the thickness direction that has a structure wherein the difference delta D in mean crystal particle diameters of the main ferrite phases between a position that is 1 mm in the thickness direction from the surface of the steel sheet and at the center of the steel sheet thickness is less than 2 [mu]m, and the difference delta V in proportion (volume%) of secondary phase structures is less than 2%. Thereby, low temperature toughness, particularly DWTT characteristics and CTOD characteristics, that are toughness tests over the entire thickness, are markedly improved.

The invention relates to a control method for switching power supply, whose specific practices are as following: a voltage checking electric circuit (VCC) examines the output voltage V<0> of a converter then delivered to an error amplifier (VA), the error amplifier (VA) carries on the comparison with an output reference voltage V and the output voltage V<0> to get an error voltage value delta V at the start time of each switching period; an error interval judgment (VC) compares the error voltage value delta V with error interval delta n, n=1,2,... N (N=2-5) of the output voltage, control pulse selection signals are outputted to cause a multistage pulse generator (MPG) to generate multistage control pulse with different dutyfactors according to the comparison result, so that the switch tube (TD)of the converter is carried on multistage control. When using the control method, the output voltage ripple of the converter is small, the dynamic response is good, anti-interference capability is strong, and the method is suitable for converters of various topologies.

The invention relates to a method for the multi-pulse sequence control of a switch power supply working in a pseudo continuous mode, which comprises the following steps that: a voltage detection circuit (VCC) detects the output voltage V0 of a convertor and transmits the output voltage to an error amplifier (VA); at the beginning time of each switch cycle, the error amplifier (VA) compares an output reference voltage Vref with the output voltage V0 to generate an error voltage value delta V; and an error burst judger (VC) compares the error voltage value delta V with a preset error burst value deltan ( n is an integer from 1 to N) of N(N is more than or equal to 1) output voltages, and outputs a control pulse selection signal according to the result of the comparison to make a multi-pulse generator (MPG) generate control pulses Pn1 and Pn2 with different duty cycles to control the switching tubes S1 and S2 of the a converter TD respectively, wherein the n is an integer from 1 to N+1. The method can realize the multi-pulse sequence control of the switch power supply working in a pseudo continuous mode. The converter adopting the control method has current critical condition limitation-free output power, small output voltage ripples, excellent dynamic response and high disturbance resistance, and is applicable to convertors of various topological structures.

The invention discloses a storage battery self discharge rapid detection method which comprises the following steps: a, placing a battery unit in a battery pack needing to be detected in a constant-temperature box, then applying an alternating current magnetic field to the battery unit in the constant-temperature box by utilizing a magnetic field generation device, and measuring an initial open-circuit voltage of the battery unit by using a voltage measurement device; b, measuring the open-circuit voltage of the battery unit by the voltage measurement device every discharge interval time until the open-circuit voltage is equal to a cut-off voltage, and thus obtaining a self discharge curve of the battery unit; and c, when delta V as a difference between open-circuit voltages corresponding to arbitrary same time points on the self discharge curve of the battery unit and a standard self discharge curve of a storage battery is larger than a rated voltage difference, judging the battery unit is unqualified. The storage battery self discharge rapid detection method can remarkably accelerate a progress of storage battery self discharge detection, and thus improving the detection efficiency and being beneficial to improving the detection accuracy.

The invention relates to a color difference evaluation and calculation method of different-color-difference-grade color samples. The method comprises the steps that a BFD data group is selected; a scatter point distribution diagram of a vision color difference value delta V and a CIELAB color difference calculation value of sample pairs is drawn; linear fitting and Stevens' power exponent equation S=aIb fitting are respectively conducted on the scatter point distribution diagram; power exponent equation optimization is conducted on different color difference formulas through selection of power exponent equations; another fifteen color difference data groups are selected, color difference values of the different color difference grade data groups and a STRESS value of the color difference value and vision color difference are calculated through optimized color difference formulas; the performance of the color difference formulas before and after being optimized is evaluated through an F inspection method; a and b values of different color difference formulas are acquired after the situation that the sixteen color difference data groups are affected with an optimized result is synthetically considered; a calculation method which is suitable for different color difference formulas and is used for evaluating color sample color differences with different color difference grades is established.

The present invention discloses a nonlinear PI voltage control method of a static reactive compensator, which includes the following steps: detecting and sampling the compensation current Isvc output by the static reactive compensator and calculating the compensation voltage VsL, sampling meansquare value Vrms of the power network voltage; calculating the difference value delta V between the voltage set value Vref and the compensation voltage VsL and system voltage Vrms; getting the control guide signal Bmsc and Btcr of mechanical threw cut capacitor and thyristor control reactor after the difference value delta V passes through an optimal nonlinear PI controller; getting logical pwl signal and angle control signal from the control guide signal Bmsc and Btcr; and sending the logical pwl signal and angle control signal to a trigger circuit and controlling the input amount of the reactor and the capacitor by the static reactive compensator. The present invention controls the static reactive compensator voltage by nonlinear PI. The responsive speed of the nonlinear PI distinctly outperforms the responsive speed of the prior PI, thereby solving the problem of overshoot of controlled variable and realizing fast and non-overshoot traction of voltage set value of SVC system with good active and static performance.

The invention relates to a lithium ion battery group matching method, which includes: S1. subjecting a plurality of lithium ion batteries to electric discharge to cut-off voltage, and then performing standing; S2. conducting constant current charging on the plurality of lithium ion batteries to cut-off voltage, recording the charging capacity C1, the charging mean voltage V1 and the first voltage change value delta E1 before and after charging, and then conducting laying; S3. Performing constant-current discharge on the plurality of lithium ion batteries to cut-off voltage, measuring the discharge capacity C2, the discharge mean voltage V2 and the second voltage change value delta E2 before and after discharge, and then conducting laying; S4. conducting charging on the plurality of lithium ion batteries, then performing laying, and measuring the voltage drop delta V and internal resistance R; and S5. according to C1, V1, delta E1, C2, V2, delta E2, delta V and R, carrying out group matching based on grading standards. Through the lithium ion battery group matching method provided by the invention, group matching can better coincide with the actual state, and the use performance of a battery module can be better, thereby realizing safe and efficient use of the battery module.

The invention discloses charging control method and system of a lithium ion battery pack, wherein the method comprises the following steps of: charging the lithium ion battery pack through a constant-current value after starting charging, monitoring the voltage of each monomer battery in real time in the whole charging process, and carrying out equalizing charging on a battery with the voltage lower than a mean value by taking the energy from the battery with the voltage higher than the mean value; when the highest voltage of the monomer battery reaches an upper limit value, converting a charging mode, and carrying out constant-voltage charging on the battery pack through the current voltage value of the battery pack; and when the highest voltage of the monomer battery is lower than the resetting value of the preset upper limit value, gradually increasing the charging voltage through preset voltage step length delta V until the voltage of the lithium ion battery pack reaches a preset constant-voltage value, and when the charging current of the lithium ion battery pack is decreased to a preset charging current end value, ending the charging. The system comprises a battery management system, charging equipment and an equalizing unit. Through the invention, the actual charging capacity of the lithium ion battery pack can reach the designed capacity under the condition of ensuring no overcharging.

To provide a plate thickness control system for a continuous rolling mill which improves accuracy on plate thickness control by formulating and regulating the influence which the correction amount of screw down position gives to the tensile force between rolling mills, and by making it easy to set up an output threshold value. This system comprises a measurement means to measure a plate speed variation Delta Vout at the exit of a rolling mill 12, a measurement means to measure a plate speed variation Delta Vin at the entrance of a rolling mill 13, a measurement means to measure a correction amount of screw down position Delta V Sn at the rolling mill 12 and the correction amount or screw down position Delta V Sn+1 at the rolling mill 13, a measured quantity calculation means 17 to calculate a measured quantity Pout ,n <(-)> , Pin ,n+1 <(+)> which affects accuracy on the plate width of the workpiece based on the plate speed variation Delta Vout , Delta Vin and the correction amount of screw down position Delta V Sn , Delta V Sn+1 , and a control output adjustment means 18 to adjust a plate control output during rolling the workpiece, using a measured quantity.

The invention discloses an ACC longitudinal kinematical modeling method based on a relative motion relation. When ACC longitudinal kinematical modeling is carried out, self vehicle state parameters and front vehicle state parameters are comprehensively considered, the state quantity xf(k) is set to be [delta d(k), delta v(k), af(k)]T, a system disturbance quantity ap (k) and an expected vehicle distance ddes are introduced, and by means of a fixed time interval strategy, a variable time interval strategy or a quadratic regression model fitting driver following behaviors, the relative motion relation between a self vehicle and a front vehicle and influences of environment parameters are brought into the ACC longitudinal kinematical modeling process. The accuracy of model calculation is improved, prediction errors are reduced, and then the prediction precision and the anti-interference capacity of a following vehicle prediction model are improved.

The present invention provides a measurement device with a function of measuring capacitance, which comprises a capacitance measurement end (207), a charging module (216), a discharging module (217), an A/D (analog/digital) conversion module (209), a double-limit comparator (210), a control processing module (215), a first voltage division circuit (205) and a second voltage division circuit (206). The charging timer of the control processing module (215) has two charging ending conditions: the maximum charging time and the first threshold voltage VH. When the charging ending conditions are satisfied, the charging timer stops timing, and the A/D conversion module (209) is controlled to measure the voltage. By adopting the method, the charging time delta t and the voltage delta V in the formula C = Ic delta t/ delta V can be obtained, and the capacitance of a capacitor (208) to be measured can be calculated. The measurement device solves the problem of the prior art that the existing measurement device can not automatically adapt to measurement of small capacitance and large capacitance.

The invention provides a hole position correcting method of an automatic hole forming system. The method comprises the following steps: a three-dimensional model of a workpiece to be punched is built;theoretical positions of a reference hole and a hole to be formed are marked; an actual position of the reference hole is machined and measured; a hole position deviation of the reference hole is calculated; based on a Kriging model, response functions delta u (x), delta v (x) and delta w (x) of the hole position deviation and mean square error functions su2 (x), sv2 (x) and sw2 (x) are obtained;three components of the hole position deviation of the hole to be formed are calculated according to the theoretical position of the hole to be formed and the three response functions; correspondingmean square errors are calculated according to the theoretical position of the hole to be formed and the three mean square error functions; and an actual position of the hole to be formed is obtained.The mean square errors of the hole position deviation of any one hole to be formed calculated through the method are determined by the hole position deviation of reference holes at two ends and the hole position deviation of multiple adjacent holes, so that the calculating precision of the hole position deviation of the hole to be formed is improved.

The invention discloses an auxiliary electricity and liquid composite braking control method applied for a hybrid vehicle to go downhill. The method comprises the following strategies: a brake torque is preferentially distributed to an electric motor, then an engine, and finally a hydraulic brake system; the value of the torque of the engine is a constant when the speed is stable; the value of the hydraulic brake torque is that T,hyd=max((Thyd_min),(T,sum-T,PM1)), and the value of brake torque of the electric motor is that T,PM1=min(((TPM_max*f(delta V,)),(T,sum-Thyd_min)), wherein T,sum is a total brake torque distributed to the electric motor and hydraulic pressure, Thyd_min is the minimum response torque that the hydraulic brake system can start, TPM_max is the maximum brake torque that the electric motor can bear, f(delta V,) is a function inversely proportional to d delta V/dt and is calibrated and obtained by the system; and when T,sum is smaller than TPM_max with a certain proportion specified by the system, the auxiliary braking of hydraulic pressure can stop. In order to achieve safe, economical and comfortable driving when going downhill, a parallel connection type electricity and liquid auxiliary braking control method is provided, and a coordinated braking method of the electric motor and the hydraulic pressure is particularly provided, so that the defect that the hydraulic brake system starts in a time delay manner is remedied, and the brake energy feedback of the electric motor after the hydraulic system starts can be maximized.

The invention relates to a method for detecting and controlling free loops by thin-strip continuous casting, which comprises the following steps that: infrared loop detectors are arranged at front and rear end points of the loops; angles alpha 1 and alpha 2 corresponding to the loop height at a central point of the width of a casting strip are measured by the loop detectors simultaneously to calculate a real value h of the loop height of the casting strip; after the loops are formed and reach a set target h0, the speed of pinch rollers is consistent with that of a cooling roller, a value of the loop quantity is constant basically, and the speed of the pinch rollers is changed correspondingly according to the change of the loop quantity in the process of forming the loops so as to form closed loop control; and the loop height h is changed by the change speed v of the pinch rollers, and the speed change rate delta v is determined according to the actual loop height and real-time speed of strip steel. In the method, an included angle between the forward direction of the strip steel at an outlet (a nip point) of the cooling roller and a vertical casting center line is kept within an ideal range in which cracks cannot be generated on the strip steel when the loops are changed due to the change of a thin-strip continuous casting process so as to prevent the quality defect of the casting strip due to the change of the loops and maintain casting continuity.