477 results about "Current constant" patented technology

The invention discloses a battery managing system (BMS) testing platform comprising a testing platform main control computer, a high-precision cell voltage simulator, a high-precision large-current constant-current source, a high-precision thermotank, a battery managing system to be tested, a whole vehicle controller simulator and the like which are connected by CAN buses. The battery managing system is connected with a cell box air cooling device, a vehicle relay assembly and the like. The battery managing system testing platform can truly simulate the output state of a battery, comprising single cell voltage, total voltage, charging and discharging current, temperature and the like of the battery, can complete various communication and command functions, protection functions, battery heavy current applying process between the battery managing system and the whole vehicle, and the test and the verification on the functions of overhead protection and the like of the battery. The invention can carry out testing evaluation on the data collection precision of the battery managing system, the evaluation precision of the charge state of the battery and the like.

A gas turbine generating apparatus according to the present invention comprises a gas turbine capable of a high-speed operation, a permanent-magnet-type generator driven at a high speed by the gas turbine, an inverter device (5) for converting alternating-current power generated by the generator into commercial alternating-current power, and a system-interconnection device (9) for interconnecting output of the inverter device to a commercial AC power supply system (10). The system-interconnection device controls the inverter device based on voltage of the commercial AC power supply system as a criterion such that output current of the inverter device is in phase with the voltage or out of phase with the voltage by a constant phase difference. A control device (18) is provided for operating the permanent-magnet-type generator (4) as a motor at a time of starting the gas turbine, and supplying alternating-current power from a direct-current power supply through the inverter device or another inverter device in addition to the inverter device to the generator for increasing a rotational speed smoothly from zero. The control device detects output current of the inverter device and controls the inverter device to keep the output current constant.

A light-source control device includes a light source including a first light emitter for emitting light and a second light emitter for emitting light due to the light emitted by the first light emitter; a constant current unit configured to maintain a current constant that is input via the light source from a power supply; a switching unit configured to switch the current to be input to the constant current unit at a designated duty ratio and cycle; and a control unit configured to control the current applied to the light source so that a rise transition time and a fall transition time of the current applied to the light source are nearly equal to each other.

A driving integrated circuit (IC) is provided. The driving IC includes a reference voltage setup circuit configured to output a reference voltage based on a test voltage and a load current control unit comparing a load voltage output from a load resistor with the reference voltage in response to a load current and maintaining the load current constant based on a result of the comparison.

The invention relates to the technical field of lithium ion batteries, and discloses a detection method for lithium-ion-battery lithium separating. The detection method for lithium-ion-battery lithiumseparating includes the following steps that S1, a to-be-detected lithium ion battery is preformed to be laid aside and sealed; S2, the preformed lithium ion battery is initially charged with the following steps of once laying, large-current constant current charging, second laying and small-current constant-current constant-voltage charging; S3, voltage data in the initial charging process is collected in real time, and if in the small-current constant-current constant-voltage charging process, the voltage continuously drops in some stage, it is judged that the lithium separating phenomenonof the to-be-detected lithium ion battery exists; S4, a judgment mechanism is set for voltage changes in the small-current charging process in the step 2 to step 4 and serves as the detection screening condition. Compared with the prior art, the detection method for lithium-ion-battery lithium separating is simple and convenient and high in reliability and can be suitable for production batch detection screening.

The invention provides a sudden capacity failure fault identifying and predetermining method for a lithium iron phosphate power battery. The charging capacity Q and terminal voltage V of the battery in a current-constant charging process are recorded in a preset sampling period to obtain a Q-V curve of the charging process; value differential is carried out on the Q-V curve of the charging processto obtain a dQ / dV-SOC curve; characteristics of the dQ / dV-SOC curve are compared with those of a standard dQ / dV-SOC curve of the battery, and change of characteristic peaks near SOC=50% and SOC=80% in the dQ / dV-SOC curve is analyzed; and LLI information is obtained. The method can be used to reflect internal state of the condition in a lossless way, whether there is a sudden capacity failure fault in the battery and reasons for the fault can be determined visually, 400 times of circulation can be predetermined and identified before sudden capacity failure, and a lithium ion power storage battery of a new energy vehicle is avoided from the risk of sudden capacity failure during operation and utilization after decommissioning.

A semiconductor integrated circuit device includes: a switching current observer for observing a switching current; a leakage current observer for observing a leakage current; a comparator which compares the switching current and the leakage current with each other; a threshold voltage controller for controlling a substrate bias voltage in order to make a ratio of the switching current and the leakage current constant; a delay observer for observing a delay amount; and a power supply voltage controller for controlling a power supply voltage in order to keep the delay amount in a predetermined range. In the semiconductor integrated circuit device, a process which enables the minimization of an operation power is carried out by controlling the threshold voltage to make the ratio of the switching current and the leakage current constant at a given clock frequency and controlling the power supply voltage to guarantee the operating speed.

A constant current and light regulating control circuit of light emitting diodes array for lighting is characterized in that the light emitting diodes array for lighting is formed by at least two lighting sub-circuits in parallel connection, each lighting sub-circuit is formed by at least two light emitting diodes in series connection. The constant current and light regulating control circuit includes a power supply circuit, a control voltage generation circuit, and a constant current light regulating circuit array. The constant current light regulating circuit array includes control sub-circuits at the same number as lighting sub-circuits in the light emitting diodes array for lighting, each control sub-circuit is formed by a triode and a current feedback resistor in series connection, collector of triode in each control sub-circuit is connected with cathode of the last diode in the correspondent lighting sub-circuit in the light emitting diodes array for lighting, and triode base electrodes in the control sub-circuits are connected in parallel to form a control point for the light emitting diodes array for lighting. Output terminal of the control voltage generation circuit is connected with control input terminal of the constant current light regulating circuits array to provide stable control voltage for the constant current light regulating circuits array.

The invention discloses a variable constant-current constant-voltage charging method which comprises the following steps: when the voltage of a battery is relatively low, trickle charging is carried out according to information fed back after sampling; when the voltage of the battery rises to a large-current charging set threshold, a large-current constant-current charging mode is adopted, wherein the charging current in the process only can fall gradually, but cannot vary reversely; then, the battery is in a constant-voltage charging stage. The variable constant-current constant-voltage charging method is provided based on analysis of the advantages and the disadvantages of common charging strategies and the charging and discharging characteristics of a lithium titanate battery, integrates the advantages of a constant-current constant-voltage charging method, a pulse charging method, a variable-current intermittent charging method and other charging strategies, and overcomes the defects of the common charging strategies.

A hybrid system modifies a control algorithm such that the super-capacitor can not only supply pulsed power, but it now can also absorb pulsed power from the load while keeping the battery current constant such that the incoming pulsed power does not stress the battery. The absorbed energy is accumulated in the capacitor and then the control algorithm operates the DC / DC converter to recharge the battery with the energy from the capacitor at a rate that optimized battery performance. If the load supplies energy to the hybrid system such that the current into the battery is within its optimal operating range, then the load is permitted to directly charge the battery. This hybrid system keeps the battery current operating in its most efficient range during both discharging and charging (the discharging and charging currents may be different values) by using the super-capacitor to supply or absorb pulsed in energy that would otherwise stress the rechargeable battery and result in reduced battery cycle life and / or reduced effective capacity over time.

The invention discloses an electric vehicle mounted power generation system. A dual-salient pole brushless direct-current power generator is adopted in the electric vehicle mounted power generation system, thus system structure is simplified and system cost is reduced. In the invention, a controller working power supply and an inside excitation source in the dual-salient pole brushless direct-current power generator is used as a power supply of a power generator controller, thus power supply safety of the generator controller is improved. The invention also discloses a control method of the electric vehicle mounted power generation system. By adopting an output current constant-current regulation and voltage-limit combined coordination control policy, power matching and system protection of a power generation system, a power storage battery and a drive system can be realized, system energy consumption is optimized and service life of the power storage battery pack is prolonged.

The invention discloses a main base station of submarine observation network based on a constant-current power supply. The main base station is connected in series in a backbone network submarine cable. The main base station is connected with a shore base station and an adjacent main base station through a submarine cable terminal box. The main base station comprises an underwater power supply anda communication control module. The underwater power supply is used for converting a constant-current power supply provided by a shore base station into a power supply of the main base station and aplurality of backup power supplies, outputting a direct-current constant-voltage power supply to the communication control module, and controlling the main base station to be networked and offline. The communication control module is used for monitoring the internal state of the main base station in a master control backup manner and sending the state information and data uploaded by the externalequipment to the shore base station. The communication control module is also used for receiving an instruction of the shore base station to perform fault isolation when the internal state has a fault. The main base station of submarine observation network based on the constant-current power supply has the advantages of high power and high reliability. The problems that a constant-voltage power supply type main base station is poor in submarine cable fault resistance and poor in robustness are solved.

The invention relates to a battery charging method and a battery charging device. The method includes S1) a step of subjecting a battery to constant-current charging with a maximum constant-current current to allow the voltage of the battery to reach a first preset voltage; S2) a step of charging the battery by a current control manner to allow the voltage of the battery to reach a second preset voltage, with the charging current being controlled to be gradually decreased along with increase of the voltage of the battery; and S3) a step of charging the battery through pulse circulation to allow the voltage of the battery to reach the nominal voltage. The charging current is decreased according to the voltage of the battery after large-current constant-current charging, thus ensuring the charging efficiency of the battery, and avoiding use of too much charging current on water decomposition at the same time. Polarization is reduced through the pulse circulation. Requirements on the maximum power of charging control are low. Hardware design is more economical.

A gas turbine generating apparatus according to the present invention comprises a gas turbine capable of a high-speed operation, a permanent-magnet-type generator driven at a high speed by the gas turbine, an inverter device (5) for converting alternating-current power generated by the generator into commercial alternating-current power, and a system-interconnection device (9) for interconnecting output of the inverter device to a commercial AC power supply system (10). The system-interconnection device controls the inverter device based on voltage of the commercial AC power supply system as a criterion such that output current of the inverter device is in phase with the voltage or out of phase with the voltage by a constant phase difference. A control device (18) is provided for operating the permanent-magnet-type generator (4) as a motor at a time of starting the gas turbine, and supplying alternating-current power from a direct-current power supply through the inverter device or another inverter device in addition to the inverter device to the generator for increasing a rotational speed smoothly from zero. The control device detects output current of the inverter device and controls the inverter device to keep the output current constant.

The invention provides a battery charging method which comprises the following steps of: setting a charging safety voltage, a charging cutoff current and a charging cutoff voltage according to a battery performance parameter; carrying out constant-voltage charging by using the safety voltage until the current of the battery is reduced to the charging cutoff current; and carrying out current-constant charging by using the charging cutoff current until the battery of the battery is increased to the charging cutoff voltage. On the basis that the charging time is not overlong, the battery charging method provided by the invention hardly influences the service life of the battery during charging, and has the advantages of being safe and reliable and high in charging efficiency, and prolonging the service life of the battery.

The invention discloses a method for detecting life of a battery performing fast charging cycling. The method comprises: a battery performs complete charging under environment temperature of 25+ / -3 DEG; a regular capacity check discharging is performed on the battery which finishes full charging and discharging and then the battery is charged with big current for about 1 hour under constant voltage or then is charged with small current for 1 hour under relatively low constant voltage (or omit the second step); the battery is then in a stationery state for 10-15 minutes and then performs a next charge-discharge cycle; after 49 times of charge-discharge cycles, long time small current constant voltage full charging is performed on the battery; capacity check discharging is then continued in order to detect 2hr capacity of the battery under a normal charging state; 50 times of cycling is defined as a set; when one set of cycling is finished, the next set of cycling tests is performed until the service life of the battery is ended.

The invention discloses an offline data driving based storage battery combined state estimation method. The method is based on offline test data driving, characteristic points extracted from offline data serve as an online identification knowledge base, and the battery SOC and capacity are estimated in a combined way online; and stored voltage change data after charging and discharging is used tocalculate an equivalent OCV value, and SOC of the battery is obtained according to the obtained offline data SOC=s(OCV, T). The SOC of a characteristic point is obtained by carrying out characteristicidentification on the battery voltage data during current-constant charging. The method is low in computational complexity, high in estimation precision, and suitable for state estimation of each battery among a lot of batteries in serial connection.

The invention relates to a formation method of a battery, in particular to an opening formation method of a lithium ion secondary battery using lithium titanate as a cathode, and the method comprises the following steps: at a formation temperature of the lithium ion secondary battery using lithium titanate as the cathode, the charging process comprises large current constant-current charge to a charge cutoff voltage and a constant-voltage charge to a cutoff current, and a solid electrolyte interfacial film is formed on the surface of the cathode material, wherein the large current is 0.2 C to 3C; the charge cutoff voltage is 1.8V to 2.8V, the cutoff current is less than or equal to 0.05C, and the formation temperature of the lithium ion secondary battery is 15 DEG C to 60 DEG C. Aiming at the characters of the lithium ion secondary battery using lithium titanate as the cathode, the large current is adopted to charge in the formation process, thus forcing to form an SEI film on the surface of the lithium titanate cathode, and the generated gas is pumped, thus avoiding the gas bulging problem owning to reaction of the lithium titanate active material and electrolyte caused by over-potential in the using process of the lithium battery and ensuring the capacity and the cyclicity of the battery simultaneously.

An online inspection system for internal resistances of batteries comprises a power supply module, a voltage inspection control module, an internal resistance inspection control module, a constant-current discharge module, an automatic gain control high-precision differential acquisition module, a microprocessor module, an abnormality detection module and a communication module. The power supply module provides a variety of power supplies for a complete machine and provides isolated power supplies for the constant-current discharge module, the high-precision differential acquisition module and the communication module. First, low-current constant-current discharge is carried out on a battery and is stopped after a certain period of time; then, variation of voltage of the battery by taking a specified time interval as a unit time in the whole process and voltage variation in a certain period of time after discharge are recorded; next, the value V of the voltage is calculated through a mathematical model by carrying out trend analysis on variation of the voltage with the time and subdividing the data; and finally, the internal resistance of a monomer battery is calculated by using the Ohm's law according to the V and a discharge current I.

The invention discloses a stepping motor subdivision driving device with current vector constant amplitude control, which comprises an RS232 interface circuit, an optocoupler isolation circuit, an LED indication circuit, a voltage and current protection circuit, a subdivision driving power supply circuit, a main control unit, a power The drive circuit, two-phase stepper motor and current detection and conditioning circuit, the RS232 interface circuit, optocoupler isolation circuit, LED indicator circuit, voltage and current protection circuit, subdivision drive power supply circuit and current detection and conditioning circuit are respectively connected with the main control unit connection; the main control unit, the power drive circuit are connected to the two-phase stepping motor in sequence, and the power drive circuit is connected to the current detection and conditioning circuit in sequence. The current vector constant-amplitude control stepping motor subdivision drive device of the present invention can overcome the defects of poor adjustability, low control precision, low reliability and poor repeatability in the prior art, so as to achieve good adjustability and control The advantages of high precision, high reliability and good repeatability.

Provided is an operating method of a full-bridge sub-module (FBSM)-based modular multilevel converter for HVDC transmission with AC-side voltage boosting. The peak value of the AC-side voltage is increased under a constant DC-link voltage by using FBSM's negative output voltage under steady state, wherein keeping the semiconductor's current rating constant during AC-side voltage boosting is in favor of reducing converter cost by decreasing energy interaction between the upper and lower arms in a leg, and further capacitance value of FBSM's capacitor under a constant capacitor voltage ripple, keeping the RMS value of AC-side current constant during AC-side voltage boosting can effectively improve transmission capacity of the converter while reducing converter cost, and keeping converter transmission capacity constant during AC-side voltage boosting can reduce RMS value of arm currents while reducing converter cost, thereby reducing power loss of FBSMs and improving converter efficiency.

The invention discloses a wet-type DCT clutch temperature control system based on fuzzy control and a control method of the wet-type DCT clutch temperature control system. The system is composed of a sensor detection module, a signal processing module and a master control module. The method comprises the steps that after the temperature of oil thrown out of an oil outlet of a wet-type DCT clutch, the rotating speed of an input shaft of a transmission, the rotating speed of a driven disk of a first clutch, the rotating speed of a driven disk of a second clutch, the pressure of the first clutch and the pressure of the second clutch are collected in real time, whether the temperature of the oil thrown out of the oil outlet of the wet-type DCT clutch is larger than or equal to a threshold is judged; if the temperature of the oil thrown out of the oil outlet of the wet-type DCT clutch is smaller than the threshold, a current constant control mode of a cooling solenoid valve is switched to; if the temperature of the oil thrown out of the oil outlet of the wet-type DCT clutch is larger than or equal to the threshold, calculated clutch temperature deviation delta Tc, clutch temperature deviation change rate d delta Tc / dt and sliding friction power P are used as input variables for fuzzy control, a three-input single-output fuzzy control mode is switched to, and the current of the cooling solenoid valve is obtained. The wet-type DCT clutch temperature control system based on fuzzy control is simple, convenient and fast to use and capable of achieving quick and accurate control over clutch temperature.

The embodiment of the invention discloses a device for charging a battery, comprising a detecting unit and a first judging unit, wherein the first detecting unit is used for detecting the current voltage value of the battery; the first judging unit is used for detecting whether the voltage of the battery in the current charging section is up to the charging limit voltage; if yes, the current value of charging current of the battery is adjusted and the battery is charged by the adjusted constant current; if no, the battery is continuously charged by the current constant electric current. The device ensures that a battery charger charges batteries with different types and improves the compatibility with the battery charger.

The invention discloses an impedance detection method for a charging line, a chip and a terminal. A current-constant electronic load module is connected to the charging line of a normally connected load, the load is controlled to be in a no-charging state, a value of currents that the current-constant electronic load module takes from a charging device via a charging line and a potential difference between the two ends of the current-constant electronic load module are obtained, an equivalent serial impedance value of the charging line is calculated according to the current value and the potential difference, a charging strategy of the load is selected according to the equivalent serial impedance value, and charging is carried out. When the load is in the no-charging state, a power input interface of the load is connected to the current-constant electronic load module, the current-constant electronic load module take currents from the charging device via the charging line, the potential difference between the two ends of the current-constant electronic load module is detected and obtained, the impedance of the charging line can be calculated effectively, the load selects the charging strategy according to the impedance, and the charging efficiency and effect are improved.

The invention relates to a high-precision battery pack charging remaining time estimation method and system. The charging process of the battery pack is subjected to staged processing, the temperaturethreshold value is set, the temperature in the battery charging process is predicted in combination with the battery pack thermal model, the remaining charging time is accurately estimated for different constant-current constant-voltage charging stages, and the prediction accuracy of the charging time of the battery pack is improved.

The invention provides a linear multi-channel LED constant-current drive circuit. The linear multi-channel LED constant-current drive circuit comprises a voltage input module, an LED module, a plurality of power tubes, a multi-channel current detection module, a constant current control module and a channel selector at least. The LED module is connected to the voltage input module; each level of LED strips are connected with one power tube, and constant current is achieved by adjusting the current of each power tube; the multi-channel current detection module is connected with each power tube and used for detecting the current of each level of LED strips; the constant current control module is connected with the multi-channel current detection module and used for adjusting the output of the power tubes to make the current constant; the channel selector is connected with the multi-channel current detection module. The forward-direction driving voltage VF of the LED strips will not be limited by preset design requirements for chips any more, larger application design flexibility can be achieved, waveform deformation caused by switching motion of adjacent switches is avoided, and simple, effective and direct control can be better achieved.

The invention discloses a magnesium alloy microarc oxidation low energy consumption black ceramic coating and a preparation method thereof. The preparation method comprises the following steps of: grinding magnesium alloy by using SiC sand paper, cleaning and drying with hot air, and standing in a drier for later use; and immersing the pre-treated magnesium alloy in electrolyte by using the magnesium alloy as an anode and a stainless steel thin plate as a cathode, and performing a microarc oxidation treatment on the magnesium alloy by adopting an alternating-current constant-current mode, taking out the magnesium alloy and cleaning with deionized water, and drying with hot air to prepare the required microarc oxidation black ceramic coating. Under a condition of lower working voltage (less than or equal to 300V), the black ceramic coating with good corrosion resistance and uniform color can be generated on the surface of magnesium alloy, and is high in efficiency, low in unit energy consumption and small in environmental pollution.