1976 results about "Current voltage" patented technology

The invention provides a sensorless motor stator temperature protection method, device and equipment, and relates to the technical field of motor control, and the protection method comprises the steps: obtaining the current voltage, current and rotating speed of a motor when the motor in a motor control system is in a running state, determining a corresponding temperature rise coefficient and a heat balance temperature according to the current voltage, the current current and the current rotating speed; obtaining a current estimated temperature according to the current voltage, the current current and the current rotating speed; determining a current predicted temperature according to the current estimated temperature, the heat balance temperature, the last estimated temperature and the corresponding temperature rise coefficient; and comparing the current predicted temperature with a preset protection threshold value, and performing temperature protection control on the motor according to a comparison result. A temperature sensor does not need to be installed in the motor, so that the installation difficulty and cost are reduced, the reliability and durability of the system are improved, and the risk that the sensor breaks down or is damaged is avoided.

The invention discloses a control method and system for improving SVG (Static Var Generator) disturbance signal generation precision, relates to the technical field of SVG disturbance signal generation, and solves the technical problem that a current disturbance signal generated by an SVG is difficult to meet the dynamic precision requirement required by multi-frequency impedance measurement. According to the technical scheme, disturbance signal attenuation caused by SVG direct-current voltage control is calculated through an observer, after phase compensation, the disturbance signal attenuation and a direct-current voltage given value are superposed to serve as outer loop input of a voltage controller, and the outer loop input is subtracted from direct-current voltage feedback; an outer ring output is obtained through a voltage controller of an outer ring and superposed with an instruction current disturbance signal to serve as an inner ring input of a current controller, and SVG operation is controlled through a current inner ring controller and a PWM modulation instruction. The influence of a direct-current voltage outer loop on actual current disturbance signals is remarkably reduced, and the SVG can still output accurate actual current disturbance signals when instruction current disturbance signals of all frequencies are injected into the SVG.

The invention provides an array substrate and a display device, and the array substrate comprises a substrate; the gate insulating layer is arranged on the substrate; the data line is arranged on the gate insulating layer; the first passivation layer is arranged on the gate insulation layer and covers the data line; the first shielding electrode is arranged on the first passivation layer, and the first shielding electrode is connected with the direct-current voltage signal output end; the second passivation layer is arranged on the first passivation layer and covers the first shielding electrode; the common electrode is arranged on the second passivation layer, and a part of the common electrode is overlapped with the data line and the first shielding electrode; the pixel electrode and the common electrode are arranged on the same layer or stacked, and the pixel electrode is insulated from the common electrode. The first shielding electrode is connected to the direct-current voltage signal, so that the data voltage signal on the data line does not affect the signal on the common electrode, coupling capacitance between the common electrode and the data line is avoided, and poor display of picture flicker is avoided.

The invention discloses an error correction method and device for non-intrusive voltage differential measurement, a medium and a product, and relates to the technical field of voltage measurement, and the method is applied to a scene in which a differential electric field sensor array is arranged in a set range with a measured conductor as the center. Comprising the following steps: constructing an initial correction model based on a sensor distance and a measured conductor voltage; under the actual working condition, the initial correction model is processed through a least square method, and a correction model is obtained; when non-intrusive voltage differential measurement is carried out, the current measured conductor voltage and the sensor distance are obtained, and a correction coefficient is determined by adopting the correction model; and completing error correction of non-intrusive voltage differential measurement based on the correction coefficient. According to the invention, the complexity of an inversion algorithm and the special requirement on the spatial position of the sensor can be reduced.

The invention provides a stable operation control method and system for a self-synchronizing voltage source centralized photovoltaic inverter, and the method comprises the steps: detecting the change rate of the DC voltage of the centralized photovoltaic inverter and the output active power of a photovoltaic panel in real time, and when the ratio of the change rate of the DC voltage to the change rate of the output active power of the photovoltaic panel exceeds a threshold value, starting the control of the stable operation of the photovoltaic inverter. A system working mode is converted from a power control mode to a voltage control mode, and a power given value and a direct-current voltage given value of a control system are adjusted in real time. A synchronous angular frequency is obtained by adding an output value of the deviation of the active power through a proportional controller and a power grid frequency value, and the phase of an output modulation voltage of a grid-connected converter is obtained after integration, so that the grid-connected power of the photovoltaic inverter is adjusted. The working points of the photovoltaic inverter can stably operate on all the working points of the photovoltaic power-voltage characteristic curve, it is ensured that the photovoltaic inverter is located at the maximum power point all the time, and then stable operation control over the self-synchronizing voltage source centralized photovoltaic inverter is achieved.

Disclosed in the present invention are a power grid impedance measurement method and apparatus. The method comprises: generating a characteristic harmonic current instruction on the basis of a harmonic-signal generation algorithm, and inputting the characteristic harmonic current instruction into a direct-current voltage feedback control loop; receiving the characteristic harmonic current instruction to generate a control signal, and performing current tracking control to obtain a harmonic current to be injected; converting an information electronic signal of a main circuit into a driving signal in a device control loop, and selecting a preset harmonic injection mode in real time on the basis of a harmonic injection target frequency; when active harmonic injection is selected, controlling the turning-on and turning-off of a switch tube, and injecting said harmonic current into a power grid; when passive harmonic injection is selected, controlling the turning-on and turning-off of an IGBT, controlling a time and a current flow direction of when a capacitor is connected to the power grid for operation, and injecting said harmonic current into the power grid; and selecting voltage and current signals to perform signal decomposition, processing and analysis, so as to obtain a power grid impedance. By means of the present embodiment, a power grid impedance is effectively measured, the disturbance to a power grid during impedance measurement is reduced, and the measurement precision is improved.

A control method and apparatus for receiving-end alternating-current fault ride-through, and an electronic device and a storage medium, which relate to the technical field of power transmission and distribution, and are used for solving the technical problems of system power imbalance, poor coordination capability, etc., in existing receiving-end alternating-current fault ride-through processes. The method comprises: determining as a faulty receiving-end converter station a receiving-end converter station in which an alternating-current fault occurs, generating an alternating-current voltage fault signal by means of the faulty receiving-end converter station, and also executing power surplus assessment, in order to obtain a surplus power value; then, transmitting the alternating-current voltage fault signal and the surplus power value to an alternating-current energy consumption apparatus; if the faulty receiving-end converter station is a receiving-end constant-voltage station, on the basis of the alternating-current voltage fault signal and the surplus power value, absorbing surplus power of an islanded power grid by means of putting the alternating-current energy consumption apparatus into use; and if the faulty receiving-end converter station is a receiving-end constant-power station, adjusting, on the basis of the surplus power value, a reference power value of the faulty receiving-end converter station by means of the faulty receiving-end converter station, and absorbing the surplus power of the islanded power grid by means of putting the alternating-current energy consumption apparatus into use.

The invention discloses a distribution box operation state monitoring method and system, and relates to the field of distribution boxes, and the system comprises an acquisition module which is used for collecting current and voltage signals of each loop in a distribution box, surface temperature distribution of a box body and opening and closing state signals of a cabinet door, and converting the collected analog signals into a digital signal sequence; the extraction module is used for receiving the digital signal sequence and extracting a signal fluctuation feature, a temperature field distribution feature and a state signal change feature to generate a three-dimensional feature set; the system can obtain loop electrical parameters, box body temperature and cabinet door state in real time, accurately analyze operation characteristics to deduce state trend, quickly position defective loop components and influence range in case of abnormity, scientifically evaluate health level, timely give an early warning, synchronously disconnect power supply of associated equipment in case of severity, effectively reduce fault shutdown, and improve work efficiency. The power utilization safety and the maintenance efficiency are improved, and stable operation of the distribution box is guaranteed.

The invention discloses a voltage out-of-limit control method and system for grid connection of a photovoltaic power generation system containing energy storage, and the method comprises the steps: building a grid connection model according to an equivalent structure diagram of grid connection of the photovoltaic power generation system containing energy storage; according to the grid-connected model, under the conditions that the line impedance is fixed and the load power is random and uncontrollable, the voltage of a grid-connected point is adjusted by controlling active power and reactive power output by an inverter; a dynamic participation factor is introduced, and the charge state of energy storage and the residual capacity of an inverter are taken into reference so as to carry out self-adaptive distribution of power. The method can effectively solve the problems of insufficient adjustment and response lag of a current power distribution network voltage out-of-limit control strategy.

The invention provides an energy coordination control system and scheduling method for multi-energy complementary new energy storage, and belongs to the technical field of new energy storage and energy technology management. The data acquisition and processing module is connected with a current and voltage sensor, a power transmitter, a meteorological station sensor and a battery management system sensor, and is used for acquiring voltage, current, power, state of charge and environmental data of photovoltaic power, wind power, energy storage and load through the sensors; and sliding window filtering and wavelet de-noising processing are carried out through the embedded processor. The method has the beneficial effects that the uncertainty of wind and light output is effectively processed by establishing a layered distributed optimization architecture and adopting a method of combining multi-objective optimization and robust optimization, and the consumption rate of renewable energy sources can be remarkably improved, the net load fluctuation can be reduced and the energy consumption can be reduced on the premise of meeting various system operation constraints. Therefore, dependence on conventional fossil energy is reduced, and the economic operation level and the environmental protection benefit of the whole energy system are improved.

The invention discloses a 10kV distribution transformer on-load voltage regulation control method and system, and relates to the technical field of transformer on-load voltage regulation, and the method comprises the steps: collecting the three-phase voltage and current of a low-voltage side of a distribution transformer and a tap switch gear signal, and loading a preset voltage regulation control mode and an oscillation region parameter; based on the acquired three-phase voltage and current of the low-voltage side of the distribution transformer and the tap switch gear signal, calculating a feeder comprehensive impedance parameter and a load reactive power parameter, and outputting a transformer operation state index; according to the transformer operation state index, the voltage regulation control mode and the oscillation area rule, current voltage out-of-limit and reactive power deviation are judged, and a voltage regulation strategy triggering instruction is generated according to the judgment result; and calculating upper and lower limit values of feed line correction voltage based on the voltage regulation strategy trigger instruction, and controlling the tap switch to execute voltage regulation action. According to the method, a combined calculation scheme of feeder comprehensive impedance and load reactive power is fused, and dynamic optimization of the triggering condition of the voltage regulation strategy is achieved.

The invention discloses a vehicle charging control method and system and driving equipment, and relates to the technical field of vehicle charging. The vehicle charging control method comprises the steps that the current voltage and current of the alternating current side of a vehicle-mounted charger are monitored; in response to the fact that the current voltage is smaller than the first preset voltage, target charging current of the vehicle is determined according to the current voltage, the first preset voltage and the current current. According to the vehicle charging control method, the real-time voltage and current of the alternating current side of the vehicle-mounted charger in the slow charging process of the vehicle are monitored in real time, the charging current of the vehicle is adjusted when the voltage of the alternating current side is lower than the preset voltage, the safe charging current is provided for slow charging of the vehicle, and therefore fire disasters and other safety accidents are prevented in advance.

A direct-current conversion circuit, which is used for providing direct-current conversion between a first direct-current voltage and a second direct-current voltage is described. The direct-current conversion circuit comprises: a transformer, which comprises a primary-side winding and a secondary-side winding, wherein the primary-side winding comprises a center tap, and a first primary-side winding and a second primary-side winding, which are respectively connected to the center tap; a primary-side circuit, wherein a first side of the primary-side circuit is connected to the primary-side winding, a second side of the primary-side circuit comprises a first end, a second end, and a third end, and a first direct-current voltage is provided between the first end and the second end of the primary-side circuit; and a secondary-side circuit, wherein a first side of the secondary-side circuit is connected to the secondary side winding.

The invention relates to the technical field of power system control, in particular to a direct-current capacitor self-synchronizing grid-connected control strategy method, system, equipment and medium, a direct-current capacitor energy dynamic model is established based on an actual energy balance relation, a direct-current voltage signal is acquired in real time, and a synchronous compensation signal is calculated based on the acquired direct-current voltage signal; performing phase compensation and gain adjustment on the synchronous compensation signal through a correction link based on the calculated synchronous compensation signal, adjusting the internal frequency of the inverter based on the synchronous compensation signal after phase compensation and gain adjustment, controlling the DC voltage through the internal frequency of the inverter, and establishing a self-synchronization control model; and based on the self-synchronization control model, establishing an adaptive control algorithm, generating a damping coefficient and a virtual inertia coefficient through the adaptive control algorithm, and dynamically adjusting control parameters according to the damping coefficient and the virtual inertia coefficient.

The invention relates to the technical field of battery modeling and photovoltaic energy storage systems, and discloses a self-adaptive battery modeling method for direct current bus voltage support of an optical storage system. The method comprises the following steps: establishing a basic model comprising a direct-current voltage source, an ohmic internal resistor and an RC polarization network; the voltage drop depth is obtained by monitoring the voltage of the direct-current bus in real time and used for correcting the polarization resistance; and performing differential operation on the voltage to obtain a change rate so as to adjust the polarization capacitance. And dynamically optimizing the battery model by combining correction results of the two, and realizing adaptive updating of model parameters. And applying the optimization model to the optical storage integrated grid-connected system. The adaptability of the battery model to the dynamic working condition is improved.

The invention belongs to the field of new energy, and particularly discloses a direct-current bus voltage control method and system of a flywheel energy storage system. Comprising the following steps: if DC bus voltage is in a normal range, DC voltage forms a q-axis current reference signal after being adjusted by a PI controller, the q-axis current reference signal generates a q-axis voltage instruction signal after being adjusted by a current control loop PI, and a dq-axis voltage instruction value is generated through decoupling; if the current control loop slightly deviates from the normal range, parameters of a PI controller are adjusted, so that an integration link plays a leading role in control output, a virtual impedance link connected to the current control loop in parallel is adjusted, and a dq-axis voltage instruction value is generated; and if the voltage is seriously deviated from the normal range, a grid-side power signal is fed forward to a machine-side direct-current voltage control loop, virtual resistance in a virtual impedance link is adjusted, and a dq-axis voltage instruction value is generated. According to the invention, the control mode is automatically switched according to different conditions of the DC bus voltage by adopting a threshold-grading regulation and control strategy, and the adaptability to large disturbance is improved while the steady-state precision of the system is maintained.

The invention provides a motor controller heating system, a control method thereof and a vehicle, and relates to the technical field of vehicle control, and the method comprises the steps: controlling the conduction states of a first switch module, a second switch module, a third switch module and an inverter, the energy storage element, the inverter, the two-phase winding in the three-phase motor and the power battery are connected in sequence to form a charging and discharging loop of the power battery; obtaining a target current and a target voltage of the power battery, a phase current of a first phase winding in the three-phase motor and a current voltage of the power battery; according to the target current, the target voltage, the current voltage and the phase current, the duty ratio of a control pulse of a first phase bridge arm in an inverter connected with the first phase winding is obtained, the first phase bridge arm is controlled according to the duty ratio so as to adjust the current of a charging and discharging loop, mutual charging and discharging between a power battery and an energy storage element can be achieved, and the charging and discharging efficiency is improved. The heating capacity of the power battery is improved, the capacity loss is reduced, and the current can be accurately controlled.

Provided are a detection method, a control device, a power distribution box, and a storage medium. The detection method applied in a power distribution box includes: obtaining a real-time input alternating-current voltage and a zero-point alternating-current phase of the power distribution box within a utility power cycle; obtaining a simulated input alternating-current voltage of the power distribution box within the utility power cycle based on the zero-point alternating-current phase; determining that the real-time input alternating-current voltage is normal in response to an alternating-current voltage difference between the simulated input alternating-current voltage and the real-time input alternating-current voltage being smaller than or equal to a predetermined threshold, or determining that the real-time input alternating-current voltage is abnormal in response to the alternating-current voltage difference between the simulated input alternating-current voltage and the real-time input alternating-current voltage being greater than the predetermined threshold.

The invention discloses a photovoltaic module early-stage fault early-warning method based on electric-thermal characteristic joint analysis, and belongs to the field of photovoltaic module early-stage fault early-warning, and the method comprises the steps: segmenting an irregular high-temperature or low-temperature region according to a temperature distribution image through employing a data segmentation algorithm, and extracting the boundary contour and area quantification characteristics of the abnormal region; performing joint feature vector construction by using the abnormal region boundary contour and area quantization feature and the current and voltage fluctuation amplitude in the electrical signal time sequence to obtain the comprehensive fault diagnosis vector; according to the preliminary fault classification label, extracting a temperature electrical corresponding association mode of a similar fault case from a historical fault diagnosis database, and obtaining an enhanced fault corresponding relation model; and generating a system risk assessment report by adopting the final fault diagnosis classification result, triggering a corresponding alarm mechanism, and judging the overall risk level of the renewable energy system.

Disclosed in the present invention are a control method and system capable of providing frequency support for a flexible interconnected power distribution network. The method comprises: using a permanent-magnet direct-drive wind turbine connected to a flexible interconnected power distribution network to provide frequency support, measuring a direct-current voltage of a grid-side converter of the wind turbine, calculating a per-unit value and the phase of the direct-current voltage, and calculating the amplitude of a modulation voltage; generating a trigger pulse signal; monitoring the rotation speed of a wind turbine rotor and the rotor position angle of a synchronous generator, and acquiring a per-unit value of optimal power; calculating an active power reference value; on the basis of active power control and current control, outputting a d-axis component and a q-axis component of a modulation voltage of a generator-side converter, and by means of rotating coordinate transformation, generating a three-phase modulation voltage in a stationary coordinate system; and generating a trigger pulse signal by means of a pulse width modulation stage. The present invention enables wind turbines to provide quick response for power distribution networks in a frequency support stage, and prevent rotation speed stalling and suppress secondary frequency drop in a rotation speed recovery stage, thereby improving the support capability of the wind turbines for power grids.

The invention discloses a hydro-generator excitation loss fault diagnosis method and device, and belongs to the technical field of power system relay protection, and the method comprises the following steps: collecting the phase current and line voltage of a hydro-generator terminal; the collected current and voltage data are stored in a register in sequence, and after the register is full, the last data is deleted when a new group of data is stored; calculating an instantaneous power integral according to m groups of current and voltage data in the register and solving a discrete form of the instantaneous power integral; normalizing the obtained instantaneous power integral to obtain an initial field loss fault index; eliminating average fluctuation of the initial field loss fault index to obtain a final field loss fault index; and judging the field loss fault by combining whether the final field loss fault index is smaller than a threshold value or not and a low-voltage criterion, and locking the field loss fault criterion by using a direct-current component criterion and a negative-sequence voltage criterion to avoid an external fault. The method does not depend on the operation state of the generator too much, has high sensitivity, and reduces the maloperation risk.

The invention relates to the field of power systems, in particular to a method and system for solving the problem of low voltage of a transformer area. The method comprises the following steps: S1, monitoring voltage data of a transformer area line in real time, and generating a low-voltage trigger signal when detecting that a current voltage value is lower than a preset voltage threshold value; s2, calculating an initial distribution proportion of active power and reactive power needing to be adjusted of the energy storage system according to the impedance characteristic parameters; s3, generating a dynamic adjustment strategy of the energy storage system; s4, collecting the deviation between the actual output power and the target value in real time through a feedback loop, and adjusting the pulse width modulation parameter of the inverter according to the deviation so as to correct the output; and S5, voltage data of the transformer area line are obtained again, if the voltage value is recovered to the preset threshold range, an adjustment completion signal is generated, and otherwise, the steps S2 to S4 are repeated based on the updated impedance characteristic parameters. The problems that in the prior art, precision is not high, active power and reactive power cooperative control cannot be achieved, and a feedback correction mechanism is lacked are solved.

An inertia cooperative control method of an integrated optical storage alternating current and direct current hybrid micro-grid comprises the steps that firstly, according to static and dynamic power capacities of energy storage units in direct current sub-grids and allowed direct current voltage deviation, sub-grid equivalent virtual resistance and virtual capacitance are calculated; secondly, RC + R type parallel virtual impedance parameters are distributed according to the power proportion of each energy storage unit, and multi-energy-storage cooperative response power disturbance according to the capacity is achieved; then, a phase angle is generated based on the mapping relation between direct-current side voltage and frequency, an alternating-current voltage amplitude instruction is determined in combination with reactive power droop control and feeder impedance voltage drop compensation, and a dq-axis voltage instruction is generated through virtual impedance compensation; normalized three-phase modulation waves are obtained through voltage-current double closed-loop control and dq / abc coordinate transformation, and six paths of PWM signals are generated to drive an interconnection converter after the normalized three-phase modulation waves are compared with triangular carrier waves. The method does not need to depend on external communication, has the capabilities of autonomous inertia support, voltage and frequency coordinated regulation and reasonable multi-source power distribution, and improves the stability and dynamic response performance of the system under island operation.

The invention discloses a novel ion transmission focusing device, and belongs to the technical field of ion transmission. The flow limiting device comprises a flow limiting hole and an octupole rod device, each flow limiting hole is a metal plate with a small hole in the center, the two flow limiting holes form a vacuum differential cavity, and certain direct-current voltage is applied to the flow limiting holes. The octupole rod device comprises two insulating positioning rings and eight conical electrode rods which are arranged at equal intervals to form a cone shape, the eight conical electrode rods are fixed through the insulating positioning rings, and the two ends of the octupole rod are connected with an ion source outlet and a mass selector inlet respectively; every four adjacent electrodes are connected through a copper sheet to form two electrodes, and the two electrodes apply two radio frequency voltages with the same amplitude and opposite phases through a power supply. The ion transmission system can be used for focusing and transmission of cluster beams, and effectively improves the beam density in a low vacuum environment. The whole device is simple in structure, easy to machine and low in cost.

The invention relates to the technical field of electric power, in particular to an alternating-current voltage regulation and conversion system and method, and the method comprises the following steps: decoupling a fundamental wave energy component and a distortion energy component of an input voltage waveform in real time through a time-frequency domain joint analysis model, and generating a fundamental wave energy channel parameter and a distortion energy channel parameter; inputting the fundamental wave energy channel parameter into a self-adaptive impedance matching network for amplification or attenuation, executing directional energy transfer on the distortion energy channel parameter, and reconstructing the distortion energy channel parameter into a compensation energy waveform matched with a load impedance characteristic; and generating a target voltage waveform, outputting the target voltage waveform to a load end, and feeding unused distortion energy back to the input side energy storage unit. According to the method, the output voltage waveform quality and the response speed of system energy closed-loop control are improved, and the method is suitable for scenes with strict requirements on electric energy quality.

The invention discloses a control method and device for improving broadband oscillation stability of a grid-forming type converter, solves the problem that the grid-forming type converter generates intermediate frequency oscillation after a virtual inductor is introduced, and belongs to the technical field of power electronic grid-connected equipment control. The method comprises the steps that virtual synchronous control is adopted by a grid-forming converter, a VSG reference voltage amplitude is obtained according to an active and reactive control loop, and a converter output voltage reference value is obtained by combining an alternating current voltage and current double closed loop of a virtual inductor, a current value of a grid-connected line is sampled, and a dq-axis component of grid-connected current under a rotating coordinate system is obtained; a differential item obtained after the dq-axis component of the grid-connected current in the rotating coordinate system is multiplied by the virtual inductance passes through a first-order low-pass filter, a dynamic virtual inductance item of the dq axis in the rotating coordinate system is obtained, the dynamic virtual inductance item is introduced into an alternating-current voltage loop input end in an alternating-current voltage and current double closed loop, and the broadband oscillation stability of the grid-forming type converter is improved.

The invention relates to a direct current fault ride-through method, a direct current fault ride-through device, direct current fault ride-through equipment and a medium. The method comprises the following steps: switching a control mode of network-forming type energy storage into an alternating-current voltage control mode or a direct-current control strategy, carrying out coordinated control on devices in a multi-terminal direct-current collecting and sending-out system, clearing fault current, and clearing the fault current by utilizing an active step-down control strategy or the direct-current control strategy at the same time. According to the method, measures such as additional direct current circuit breakers are not needed, control is flexible and easy to achieve, the multi-terminal direct current collecting and sending-out system after fault clearing is controlled to be recovered by judging the operation state of the multi-terminal direct current collecting and sending-out system, and safe and stable operation of the multi-terminal direct current collecting and sending-out system is facilitated.

The invention belongs to the technical field of power electronics and semiconductor devices, and provides a transistor on-resistance high-precision comparison method, which comprises the following steps of: generating and outputting a direct-current voltage # imgabs0 # which can quickly adjust a numerical value and has load capacity through a direct-current voltage adjusting module; the grid driving module generates and outputs a pulse signal # imgabs3 # of which the voltage can be quickly adjusted based on the direct-current voltage # imgabs1 # and the pulse voltage # imgabs2 #; applying a pulse signal # imgabs4 # to the transistor to be measured through the power module, and measuring the on-resistance of the transistor to be measured under the gate driving voltage; and switching the gate driving voltage in the microsecond-to-nanosecond magnitude delay, and measuring the on-resistance of the transistor to be measured under the switching gate driving voltage based on the pulse signal # imgabs5 #. According to the method, the on-resistance of the transistor to be tested under different gate driving voltages can be tested in the pulse circuit, the measurement delay is shortened to several nanoseconds from several minutes of a traditional double-pulse circuit, and the performance of the transistor reliability evaluation circuit is effectively improved.

The invention belongs to the technical field of water electrolysis hydrogen production, and discloses a PEM electrolytic bath temperature control method based on feed-forward compensation and a related device, and the method comprises the steps: collecting the input power of an electrolytic bath and the outlet temperature of the electrolytic bath at the current moment; calculating the voltage and current of the electrolytic cell based on the outlet temperature and the input power of the electrolytic cell, and obtaining the heat production power of the electrolytic cell based on the current voltage and current of the electrolytic cell; based on the heat production power of the electrolytic cell and the outlet temperature of the electrolytic cell, constructing a mapping relation between the input power of the electrolytic cell and the outlet temperature of the electrolytic cell and the circulating water flow; and feed-forward compensation of the circulating water flow is carried out based on the mapping relation. According to the method, the mapping relation between the input power and the outlet temperature of the electrolytic cell and the circulating water flow is constructed. The mapping relation considered by multiple factors can more accurately reflect the relation between the heat production of the electrolytic bath and the circulating water flow, so that the accurate control on the circulating water flow is realized, and the temperature control precision is improved.

The invention discloses a self-adaptive multi-power-supply vehicle-mounted refrigerator, and relates to vehicle-mounted refrigerator power supply control, the key points of the technical scheme are that the self-adaptive multi-power-supply vehicle-mounted refrigerator comprises a box body, the box body is provided with a placing cavity for placing a compressor and a control module, and the control module comprises a power supply connecting module used for being connected with a low-voltage storage battery or a power supply to output a power supply voltage signal; and the direct-current voltage reduction module is connected with the battery connection module and used for converting the power supply to output driving voltage for driving the compressor when responding to power supply of the power supply. Stable work of the vehicle-mounted refrigerator can be guaranteed through power supply of the double power sources, the power source and the low-voltage storage battery supply power to the vehicle-mounted refrigerator in a self-adaptive mode, when the temperature rise rate of the vehicle-mounted refrigerator does not reach the standard, supplementation can be conducted through the power source, and therefore the requirement for electricity needed by vehicle running is met, and in the aspect of dynamic energy supplementation, the energy utilization rate of the vehicle is improved. The power supply proportion of the low-voltage storage battery and the power supply is dynamically adjusted by collecting and detecting the conditions of the heating rate and the temperature change delay.