68results about How to "Avoid overvoltage" patented technology

The invention discloses a lithium battery protection circuit and a protection method thereof. The protection circuit is arranged in the lithium battery pack and is connected with the two poles of the cell of each battery forming the lithium battery pack, and comprises a front end acquire unit, an MCU master unit and a charging and control unit. The protection method comprises that the front end acquiring unit acquires parameters of the voltage of the cells of the batteries in real time and transmits the parameters to the MCU; according to the given charging current and the read data, the MCU calculates and outputs a control signal of PWM to control a charger for charging; the MCU reduces the charging current for charging or stops the charge in due time so as to necessarily protect the batteries. The protection circuit and the protection method adopt a feedback mode of simple link cell voltage, thereby effectively avoiding the defects of charging management when only the voltage of two poles Pack+ and Pack- of the lithium battery is taken as the reference; and when the voltage of the cell of a certain link reaches the amplitude limiting value, the MCN regulates the command to reduce the charging current and prevents the voltage of the battery from overrunning, thereby ensuring the safety of the lithium battery and improving the charging efficiency at the same time.

The invention discloses an AC-DC (alternating current-direct current) drive output filter capacitor quick active leakage circuit which comprises an output filter capacitor-side voltage detection circuit, a switch SW drive circuit, a switch SW and a low resistance load resistance RL, the switch SW drive circuit force the switch SW to be switched off when AC-DC convertor output filter capacitor-side voltage sensed by the output filter capacitor-side voltage detection circuit is larger than leakage voltage, and weak current flows through low resistance load RL; the switch SW drive circuit is in state overturn to force the switch SW to be switched when the AC-DC convertor output filter capacitor-side voltage sensed by the output filter capacitor-side voltage detection circuit is smaller than the set leakage voltage, and an output filter capacitor is enabled to discharge rapidly by the aid of the low resistance load RL. The AC-DC drive output filter capacitor quick active leakage circuit is quick in discharge, delayed start-up circuits are reset rapidly after power outage, discharge current is controlled to the greatest extent, and over-current damage to the switch SW is avoided; power consumption is lowered, and under the normal state, the discharge current can be integrally controlled under 100mW in power consumption.

The invention provides a battery charge method which comprises the following steps of: confirming the largest charge current of a battery, and sensitive voltage of the battery; performing constant-current charge on the battery by using the largest charge current of the battery, when the voltage of the battery reaches the sensitive voltage of the battery, stopping constant-current charge to the battery, and leaving the battery to stand; performing pulse charge on the battery by using first charge current and first discharge current, wherein the first charge current is smaller than the largest charge current; the first discharge current is smaller than the first charge current. By adopting the battery charge method provided by the invention, the phenomenon of partial over-voltage of a cell material of the battery in the battery charge process is avoided, the risk of material failure is reduced, the circulation service life of the battery is remarkably prolonged, and the security property of the battery is improved.

The invention relates to a high-capacity and high-compaction artificial graphite negative electrode material, a preparation method thereof and a lithium ion battery. The preparation method comprises the steps of selecting at least two of pitch coke, petroleum coke and needle coke as graphite raw materials, and uniformly mixing with a coating agent to obtain a mixed material; and performing graphitization on the mixed material at 3,000-3,300 DEG C under a protection atmosphere to obtain the high-capacity and high-compaction artificial graphite negative electrode material. According to the preparation method of the high-capacity and high-compaction artificial graphite negative electrode material, the problem that the material is easy to press excessively due to inappropriate selection of theraw material cokes is solved by selection and matching of raw material cokes with different hardness, and the prepared graphite negative electrode material has appropriate hardness and rebound rate.A pole plate prepared from the artificial graphite negative electrode material is high in compaction density, an electrolyte is rapidly immersed, and the electrochemical performance of the lithium ionbattery is prolonged.

The invention provides a power optimal distribution control method of energy storage of an all-vanadium redox flow battery used in a high-capacity wind power plant. The power optimal distribution control method of the energy storage of the all-vanadium redox flow battery used in the high-capacity wind power plant adopts an all-vanadium redox flow battery (VRB) energy storage systems port with cascade connection between a direct current (DC) / alternating current (AC) convertor and a bi-direction DC / DC convertor. Difference of values of state of charge (SOC) of VRBs in a process of restraining power fluctuation of the wind power plant, wherein the VRBs are connected in parallel in a multi-level mode is considered. A power distribution module with a first choice of a charging state of each level VRB being an optimal charge-discharge battery set and an optimizing power distribution unit of corresponding maximum charge-discharge power a limiting value of charge-discharge voltage being the constraint condition is designed, wherein the power distribution module is capable of achieving a multi-level VRB system. According to the power optimal distribution control method, a conventional distribution principle of average power is abandoned, power fluctuation of the wind power plant is restrained well, number of circulate charge-discharge times of each VRB set in a high-capacity energy storage system is effectively reduced at the same time, and the batteries are enabled to operate in a safe and stable operation area.

The invention discloses a real-time asphalt road compactness monitoring method which comprises the steps of (1) establishing a linear relation between compactness and detection density of a non-nuclear density gauge; (2) establishing a linear relation between a compaction value and the compactness; (3) according to the lower compactness limit requirement of a construction site and according to the linear relation between the compaction value and the compactness, established in the step (2), determining the lower limit of the compaction value; (4) monitoring the compactness in construction in real time, enabling an vibratory roller operator to control a vibratory roller through observing the compacted or uncompacted information displayed on an industrial control computer, continuously rolling when in uncompaction, and stopping rolling when in compaction. The real-time asphalt road compactness monitoring method is novel and reasonable in design, convenient to realize, capable of improving the compaction quality and efficiency of an asphalt road and avoiding damage to the road, relatively high in compactness detection accuracy, low in realization cost, strong in practicability, and high in popularization and application values.

The invention relates to a DC power grid line fault protection method. The method comprises steps: travelling wave signals at each measurement point are monitored in real time, if a protected set threshold is reached, a corresponding DC circuit breaker is tripped, all circuit breakers are finally tripped to realize separation of three DC subsystems, and the control mode of each subsystem converter station is switched. According to the travelling waves acquired at the measurement point, whether the fault is subsystem internal fault or subsystem external fault is judged by each subsystem through a fault positioning logic. If the subsystem external fault is judged according to the fault positioning logic, the line of the fault is determined according to the fault positioning logic, or otherwise, the subsystem internal fault is judged. According to an instruction of a dispatching system, the control mode of each converter station and a power control instruction are changed. The technical scheme of the invention can effectively shorten time needed for fault positioning, and power transfer brought by large-range DC power grid locking and influences on the stability of an AC and DC system can be reduced as much as possible. The phenomenon that the disclosed method is not applicable along with complexity of the DC power grid structure does not happen.

The invention discloses a method, a device and a system for estimating the peak power of a battery pack. The method comprises the following steps of obtaining a discharge power limit value and a charging power limit value of the battery pack according to the charged state of the batteries in the battery pack and the temperature of the battery pack; acquiring the minimum voltage value and the maximum voltage value of the batteries in the battery pack, and determining the discharge peak power limit coefficient and the charging peak power limit coefficient based on the preset voltage limit condition, the minimum voltage value and the maximum voltage value; and calculating the discharge peak power of the battery pack and the charging peak power of the battery pack based on the discharge power limit value, the charging power limit value, the discharge peak power limit coefficient and the charging peak power limit coefficient. According to the method of estimating the peak power of the battery pack provided by the embodiment of the present invention, it is possible to adjust the peak power of the batteries in the battery pack by the battery voltage so as to avoid the risk of undervoltage or overvoltage during discharge or charging of the peak power.

The invention discloses a driving circuit for a neutral point clamped (NPC) three-level topology and application. The driving circuit comprises a wave sealing time sequence protection circuit and a logic interlocking circuit which are sequentially connected, wherein the wave sealing time sequence protection circuit comprises a logic AND gate, the situation that a PWM pulse sequence of a second tube is a low level and a PWM pulse sequence of a first tube is also a low level by the logic AND gate, and/or a PWM pulse sequence of a third tube is a low level and a PWM pulse sequence of a fourth tube is also a low level, the logic interlocking circuit comprises a driving photocouple, an input signal of the driving photocouple is a PWM pulse sequence output from the wave sealing time sequence protection circuit, and complementary conduction of the first tube and the third tube and/or complementary conduction of the second tube and the fourth tube is achieved by the driving photocouple. By thedriving circuit, all pulse sequences of the control chip are low levels during power-on period, a complementary tube confirms to a reliable logic complementary relation, the cutoff time sequence requirement during wave sealing is met, and the switch tube is prevented from bearing overvoltage during overcurrent cutoff.

The invention discloses a novel full-automatic punching device with a pipe visual inspection function. The novel full-automatic punching device comprises a machine body, a feeding funnel, an upper rack, a lower rack and a discharging funnel. The feeding funnel, the upper rack, the lower rack and the discharging funnel are all arranged on the machine body. A feeding station, a punching station, a turnover station and a discharging station are arranged on the lower rack. Shaking plates, a pipe adjusting assembly and a jacking assembly are arranged on the feeding funnel, and the shaking plates are arranged at the bottom of the feeding funnel at intervals. A pipe visual inspection assembly is arranged at the feeding station. A punching mold further comprises a pipe pushing in-mold assembly, apipe waste clearing assembly and an oil supply lubricating device. The novel full-automatic punching device is suitable for carrying out punching on pipes of different types; automatic feeding and discharging are achieved; the machining efficiency is high; the problem of pipe collision is effectively solved; surface scratching and damage are avoided; the machining quality is high; demounting is convenient; problems happening to equipment in the production process can be found in time; maintenance is carried out rapidly; and the maintenance cost is reduced.

The invention discloses a high-purity copper rotating target welding end head semi-automatic straightening method. According to the high-purity copper rotating target welding end head semi-automatic straightening method, after a copper alloy tail cover is fixed to a rotating clamping device, the rotating clamping device is started to make a high-purity copper rotating target rotate, the straightness of a copper alloy end head is measured through a straightening measuring device, so that inner and outer straightening points and the straightening value are confirmed, the copper alloy end head isheated utilizing a heating device and is heated to a specified temperature, a semi-automatic straightening device is placed at the outer straightening point and abuts and jacks the outer straightening point, the straightening measuring device is placed at the inner straightening point, the semi-automatic straightening device is operated manually until the pointer moving value inside the straightening measuring device reaches the straightening value, heating of the heating device is stopped, the high-purity copper rotating target is cooled to the room temperature, and inspecting is performed on straightening of the high-purity copper rotating target until the straightening value is less than or equal to 0.3 mm. By means of the high-purity copper rotating target welding end head semi-automatic straightening method, a high-purity target material pipe does not deform, the straightening effect is good without rebounding, the straightening precision is high, and the finished product rate ishigh.

The invention relates to a metallization power capacitor rapid aging testing device which comprises a voltage transformation module, a measurement metering protection module, a constant temperature box and a control module. The voltage transformation module is used for improving power supply voltage to a voltage value needed by voltage testing. The measurement metering protection module is used for achieving testing time metering, input voltage measurement, total current measurement, electric reactor current measurement, capacitor current measurement and capacitor voltage measurement, and used for carrying out delay protection and short-circuit instantaneous protection on overvoltage and an overcurrent. The constant temperature box is used for providing a constant temperature environment in a testing process, and a metallization power capacitor to be tested is arranged in the constant temperature box. The control module is used for controlling stating and stopping of the whole testing device and operation of the constant temperature box. The metallization power capacitor rapid aging testing device effectively resolves the problems that in the prior art, a capacitor aging testing device is complex in structure, poor in safety, long in testing cycle, and high in cost and energy consumption.

The invention discloses a centralized-local comprehensive voltage control method and device suitable for a power distribution network with high-proportion photovoltaic access. The method comprises thefollowing steps: in a centralized control phase, acquiring photovoltaic and load prediction data of a power distribution network at a first sampling interval, and optimally calculating and updating the inverter droop slopes of each photovoltaic access node by using a pre-constructed centralized control model and taking the minimum loss of the power distribution network as an optimization target and considering a network power flow constraint, an inverter droop curve slope constraint and an inverter reactive output constraint; and in a local control stage, acquiring the real-time measurement voltages of each photovoltaic access node at a second sampling interval in the first sampling interval, and determining a voltage-reactive droop curve according to the current droop slopes of the inverters of each photovoltaic access node so as to perform local control on the corresponding node. According to the invention, optimization of reactive power control is realized by combining centralizedcontrol and local control modes, so that photovoltaic prediction errors and power fluctuation can be quickly responded, and effective coordination among equipment can be realized.

The invention relates to a power distribution network overvoltage suppression method and system based on an active power limit value algorithm. The method comprises the steps as follows: when the voltage value of a key busbar of a photovoltaic system of a power distribution network exceeds a power distribution network overvoltage alarm value, active power limit values of the key busbar and commonbusbars are determined according to the overvoltage alarm moment of the power distribution network as well as active output values and voltage values of the key busbar and the common busbars of the photovoltaic power generation system of the power distribution network at the current moment, the power extraction capacity of each busbar in the photovoltaic power generation system is determined according to the active power limit value of the key busbar and the active power limit values of common busbars, and suppression of overvoltage of the power distribution network is realized according to the power extraction capacity of each busbar. According to the technical scheme, active output of the photovoltaic system is limited and regulated, the occurrence rate that the voltage is out of limit is effectively suppressed, the problem of high costs of the prior art is solved, and overvoltage suppression of the power distribution network is realized precisely on the premise of simple configuration.

The invention relates to the technical field of edge computing, particularly provides a voltage fault monitoring method of a transformer area and an intelligent Internet-of-things agent device, and aims to solve a technical problem that the voltage of a line at the side of a power distribution transformer area is out of limit. The method comprises the following steps of acquiring detection data of each monitoring terminal in a transformer area through a local data acquisition interface; on the basis of the detection data of each monitoring terminal in the transformer area and the downloaded transformer area photovoltaic energy storage voltage out-of-limit control application program, whether a voltage out-of-limit fault occurs in photovoltaic energy storage in the transformer area being diagnosed; and if yes, stabilizing the photovoltaic energy storage voltage of the transformer area by using the downloaded transformer area photovoltaic energy storage voltage out-of-limit control application program, otherwise, continuously carrying out voltage out-of-limit fault diagnosis on the photovoltaic energy storage in the transformer area. According to the method, through distributed photovoltaic and energy storage optimization control adjustment, voltage out-of-limit of the line at the power distribution area side is prevented, and requirements of the power quality of the power grid in the area and the power generation income of the user are met while the photovoltaic power generation power of the user is not reduced.

The invention discloses a self-adaptive droop control method and system for a converter station after large disturbance, and belongs to the technical field of power systems and automation thereof. Themethod comprises the following steps: acquiring system parameters of a converter station of a multi-terminal flexible DC power transmission system, and determining conditions for adaptive droop control after large disturbance of the converter station according to the system parameters; when the converter station meets the condition of adaptive droop control after large disturbance, acquiring an adaptive droop control coefficient according to system parameters, and performing droop control on the converter station according to the adaptive droop control coefficient. According to the method, the droop coefficient can be adaptively adjusted, the problem of voltage out-of-limit under large disturbance of a traditional droop method is avoided, and meanwhile, reasonable power distribution can be realized.

The invention discloses a semi-automatic straightening method for a high-purity aluminum rotating target welding end. The method includes the steps that after an aluminum alloy tail cover is fixed toa rotary clamping device, the rotary clamping device is started to rotate a high-purity aluminum rotating target, the straightness of an aluminum alloy end is measured through a straightening measurement device, and therefore the inner and outer straightening points and straightening values are determined; a heating device is used for heating the aluminum alloy end, the aluminum alloy end is heated to a specified temperature, a semi-automatic straightening device is placed at an outer straightening point and further abuts against the outer straightening point, the straightening measurement device is placed at an inner straightening point, and the semi-automatic straightening device is manually operated until the moving value of a pointer inside the straightening measurement device reachesa straightening value; and heating by the heating device is stopped, the high-purity aluminum rotating target is cooled to an indoor temperature, and straightening of the high-purity aluminum rotatingtarget is inspected until the straightening value is smaller than or equal to 0.3mm. By adoption of the straightening method, a high-purity target material tube is not deformed, the straightening effect is good and does not rebound, and the straightening precision and rate of finished products are high.

The invention discloses a cabinet type air-conditioner with a self-protection function. The cabinet type air-conditioner comprises a housing, an inner-circulation heat exchange system, an outer-circulation heat exchange system, a self-monitoring device and a control system; the inner-circulation heat exchange system is arranged inside the housing, while the outer-circulation heat exchange system is arranged outside the housing; the self-monitoring device and the control system both are arranged below the housing; a dryness detection module and a temperature detection module are arranged in the self-monitoring device. According to the cabinet type air-conditioner with the self-protection function, the self-monitoring device is arranged inside the air-conditioner to detect and monitor the environment in the air-conditioner in real time so that the humidity and the temperature inside the air-conditioner can be kept in the optimal states, and therefore, electricity conduction between internal electric wires due to high damp or electrostatic sparks due to dryness in the air-conditioner can be effectively prevented and the running safety of the whole device can be improved; furthermore, an excellent protection effect on the air-conditioner is achieved.

A first wire (WP1, WN1, WC1) is provided between a first converter unit (U1) and a DC bus line (PL4, NL4, CL4). A second wire (WP2, WN2, WC2) is provided between a second converter unit (U2) and a DC bus line (PL4, NL4, CL4). A third wire (WP3, WN3, WC3) is provided between a third converter unit (U3) and a DC bus line (PL4, NL4, CL4). A first fuse (FP1, FN1, FC1) is inserted in each of the first wire (WP1, WN1, WC1). A second fuse (FP2, FN2, FC2) is inserted in each of the second wire (WP2, WN2, WC2). A third fuse (FP3, FN3, FC3) is inserted in each of the third wire (WP3, WN3, WC3).

The invention discloses an active distribution network voltage coordination control system and method based on sensitivity analysis. The system comprises: a voltage overrun target screening module forselecting a node with the largest voltage overrun in the active distribution network system; ; a FCE active power regulation selection module for selecting the best active power device according to the voltage sensitivity matrix; a reactive power equipment selection module for seleting the optimal reactive power equipment according to the voltage sensitivity matrix; an FCE active power regulatingmodule for completing the distribution of the active power target value; a reactive power regulating module for completing reactive power target value transmission; a synergistic interactive controlis used for carrying out active PID regulation and reactive PID regulation on an intelligent manager according to an active target value and a reactive target value, respectively, and completing fastcomputation of FCE control; an intelligent management controller is used for setting the active power target value of the active power equipment and the reactive power equipment respectively. The invention achieves the requirements of multi-objective coordination and optimization control of an active distribution network.

The invention provides an electromagnetic disturbance test system, which is used for carrying out electromagnetic interference test on a tested device. The system comprises a coupling and decoupling network and a power supply device, wherein the coupling and decoupling network comprises a coupling circuit and a decoupling circuit, the coupling circuit is connected between the tested device and thedecoupling circuit to input an interference signal, and the power supply device is connected with the coupling circuit in parallel to provide a test voltage to the tested device. According to the electromagnetic disturbance test system provided by the invention, the power supply voltage and the coupling unit are connected to the tested device in parallel in the electromagnetic compatibility testof the power device, the overvoltage phenomenon caused by resonance is avoided, the smooth electromagnetic compatibility test is ensured, and the user experience is improved.

The invention discloses a method for detecting transverse compactness and uniformity of a roadbed. The method comprises the steps that before a roadbed to be compacted is compacted, whether a first linear regression equation K = aF<SE> + b and a second linear regression equation s = cI<n> + d can be obtained or not is judged, wherein in the formulas, K is the transverse compactness, F<SE> is the resultant force of the counter force of a compacted layer, s is a transverse compactness uniformity parameter, and I<n> is a transverse uniformity index; if yes, the first linear regression equation and the second linear regression equation are obtained; acceleration information of a road roller is acquired in the process of compacting the roadbed to be compacted; the resultant force of the counter force of the compacted layer and the transverse uniformity index of the compacted layer are calculated according to a calculation rule and the acceleration information; and the transverse compactness of the roadbed to be compacted is determined according to the resultant force of the counter force of the compacted layer and the first linear regression equation, and the transverse compactness uniformity parameter of the roadbed to be compacted is determined according to the transverse uniformity index of the compacted layer and the second linear regression equation. According to the method, the transverse compactness and uniformity of the roadbed can be detected in real time.