2809 results about "Duty cycling" patented technology

The invention discloses a charging chip real-time power scheduling control method, and relates to the technical field of new energy automobile charging pile power scheduling, and the method comprises the following steps: S1, obtaining the operation parameters of charging equipment in real time, including the voltage fluctuation value of an input power grid, the output current of a charging interface, and the temperature of a charging chip; according to the method, the power grid voltage fluctuation, battery SOC / temperature and chip working condition multi-source data are collected in real time, a multi-target optimization model of dynamic weight distribution is combined, the service life loss of the battery is minimized, the charging efficiency and the power grid load are balanced at the same time, the user charging mode and the battery state difference are taken into consideration by adopting a priority scheduling strategy, and the charging efficiency is improved. Millisecond-level power fine control is achieved through cooperative adjustment of the PWM duty ratio and the switching frequency, personalized charging requirements are met, the overall energy efficiency is improved, a dual safety defense line is constructed through a graded load reduction protection mechanism and a fuzzy control algorithm, and a power distribution scheme is intelligently reconstructed when a power grid is abnormal or a battery is overheated.

The invention provides a dynamic reconfigurable battery energy storage system balance control method and device based on PWM duty ratio modulation. Belongs to the battery system control field. Voltage information of all single batteries in the energy storage system is collected in real time, total loop current, system operation modes and temperature distribution are monitored synchronously, a controller dynamically calculates charge state values of all the single batteries based on the information, a target object to be balanced is recognized, and meanwhile a global battery consistency evaluation index is established. The method dynamically adjusts the maximum allowable equalization current and generates an equalization topology. The modulation frequency, the duty ratio spectrum amplitude and the phase distribution are adjusted through PWM, and the maximum duty ratio is limited. All the operation instruction sets take effect synchronously at the starting moment of the next equalization period. Besides, the efficiency and working condition mapping table in the historical learning library is synchronously updated to form a closed-loop self-evolution optimization mechanism, so that the balance efficiency optimization of the system in a dynamic scene is realized, and the voltage overshoot is ensured to be within a set threshold value.

The invention discloses a charging and discharging control method and device for an elevator energy storage system, a medium and a product, and relates to the field of data processing. The method comprises the steps that real-time operation data such as the position and the load capacity of an elevator car are obtained, and the instantaneous power generation power and the power change rate of a traction machine are determined accordingly; determining a power change predicted value in a future preset time period based on the parameters, and obtaining the total amount of power generation energy required to be stored by the energy storage system through zero setting of a positive value, integral operation and efficiency compensation; according to the power change rate, the state of the energy storage unit and the power grid electricity price time period, the charging and discharging priorities fed back by the super capacitor, the lithium battery and the power grid are determined; controlling the bidirectional DC / DC circuit to switch charging and discharging modes according to the priority, and adjusting the PWM duty ratio of the brake resistor; and based on the charging and discharging mode and the duty ratio, charging and discharging control over the elevator energy storage system is achieved. According to the method, the problem of inaccurate real-time matching of the dynamic load and the energy fluctuation of the current elevator energy storage system can be relieved.

The invention provides a frying and baking equipment heat preservation automatic control method and system, and relates to the technical field of food processing equipment control, and the method comprises the steps: collecting temperature signals of different positions through a plurality of groups of thermocouples and infrared thermal imaging sensors which are arranged in a frying and baking area, constructing a dynamic three-dimensional temperature field model, and obtaining a dynamic three-dimensional temperature field model; calculating a temperature standard deviation and a maximum temperature gradient in real time according to the dynamic three-dimensional temperature field model; and when the temperature standard deviation is larger than or equal to a preset threshold value, according to the heat distribution difference of the three-dimensional temperature field model, a multi-region differential compensation strategy is generated, the power distribution proportion of each heating unit is dynamically adjusted, and the duty ratio parameter of pulse width modulation is optimized in real time. Through multi-sensor accurate monitoring, dynamic regulation and control and intelligent stop judgment, uniform and stable temperature control, energy conservation and consumption reduction are achieved, the service life of equipment is prolonged, meanwhile, the use safety of a user is guaranteed, and the cooking experience is improved.

The invention discloses a photovoltaic hydrogen production power supply topological structure based on MPPT and a control method, and relates to the technical field of renewable energy electrolysis hydrogen production, and the photovoltaic hydrogen production power supply topological structure mainly comprises a photovoltaic power module, a direct current bus, a water electrolysis hydrogen production unit, an energy storage unit and a control unit. The photovoltaic power modules are connected in parallel to the direct current bus through the independent DC / DC converter, and are matched with the automatic identification and scheduling functions of the control unit, the system operation strategy is automatically adjusted when the modules are newly added or faults exit, and plug-and-play, fault isolation and power reconstruction of the photovoltaic power modules can be supported; the duty ratio change step length of the DC / DC converter is limited when the current rapidly fluctuates due to the change of the photovoltaic output power, the current change rate of the electrolytic cell stack is effectively controlled, the service life protection of the electrolytic cell can be considered, the high modular access capability is achieved, multi-source collaborative scheduling is supported, and bus voltage stabilization and system current sharing optimization can be achieved.

The invention relates to a temperature control method, device and equipment for a new energy automobile air conditioner and a medium, and the method comprises the steps that the environment temperature in an automobile and heater surface temperature data are collected in real time through multiple sensors, a preliminary adjusting instruction is generated in combination with the temperature preset by a user, and a power distribution strategy is dynamically optimized based on battery residual current; a duty ratio adjusting technology is adopted to carry out power control on a heater power supply circuit, overload risk grading response is realized through a grading safety threshold detection mechanism, a closed-loop feedback mechanism is further introduced, and control parameters are dynamically optimized according to real-time temperature feedback and a battery health state. And the problems of large temperature deviation of multiple regions and unbalanced battery energy consumption are solved. Through temperature-current-battery multi-dimensional fusion control, hierarchical dynamic protection and an energy consumption equalization algorithm, the driving comfort is guaranteed, meanwhile, the overload risk of the system is effectively reduced, the service life of the battery is prolonged, and the method is suitable for the intelligent safety temperature control scene of the new energy automobile air conditioner.

The invention provides an intelligent POB module integration platform and a control method thereof, and the method comprises the steps: detecting the state data of each pixel point of an LED display screen through an optical sensing array, obtaining a damaged pixel point in the LED display screen, recording the damaged pixel point to a storage unit, and maintaining a dead pixel position table in the storage unit; compensating the brightness of the bad pixel points through the neighborhood pixel points; the display content of the LED display screen is predicted through AI during compensation, and the refresh rate of the LED display screen is dynamically driven according to the predicted display content; according to the physical pixel density, the LED display screen is divided into grid partitions, the grid partitions are sorted according to priorities, the real-time power consumption of each partition is calculated after the LED display screen is refreshed, and if the real-time power consumption is larger than a preset threshold value, the current and the duty ratio of the low-priority area are reduced. Through the control method, a compensation scheme can be started in time after a dead pixel occurs, the maintenance and replacement cost is reduced, and the operation and maintenance efficiency is improved.

The invention provides an energy-saving thermal-insulation self-adaptive dynamic control method and system for frying and baking equipment, and relates to the technical field of data processing, and the method comprises the steps: 1, collecting the surface temperature distribution, thickness gradient and environment temperature and humidity data of food materials in real time, extracting three-dimensional thermal diffusion morphological features, and generating an initial morphological feature vector; and step 2, based on a real-time deviation value of a set target temperature and an actually measured food material core temperature, a pseudo partial derivative estimation value is calculated in combination with the morphological feature vector, and periodic intermittent power parameters including a duty ratio and a period are generated according to the pseudo partial derivative estimation value. Through multi-source data acquisition and analysis, parameter dynamic calculation and optimization and knowledge base intelligent matching, accurate temperature control, high efficiency and energy saving are realized, and the service life of equipment is prolonged while the food material cooking quality is improved.

An electronic controller is configured to adjust the duty cycle, between a respective pairs of semiconductor switches of the primary converter of a direct-current-to-direct-current converter based on reducing or minimizing one or more of the first estimated line-to-line DC offset voltage, the second estimated line-to-line DC offset voltage, and the third estimated line-to-line DC offset voltage. Further, the electronic controller is configured determines duty cycle adjustments based on oversampling (e.g., enhanced data processing with interpolation) of smoothed or integrated representation of the first estimated line-to-line DC offset voltage, the second estimated line-to-line DC offset voltage, and the third estimated line-to-line DC offset voltage.

The invention relates to the technical field of electric scooters, in particular to a vehicle battery energy-saving control system of a high-strength impact-resistant scooter, which comprises an impact-resistant battery bin, a battery energy-saving control system and a battery energy-saving control system, wherein the impact-resistant battery bin comprises a multi-layer composite shell, a vibration sensor and a filling layer; the energy-saving control module comprises an intelligent detection unit, a central controller and a power optimizer; the power optimizer is used for adjusting the PWM duty ratio of the motor driving circuit according to the power mapping table; the energy recovery module is used for receiving brake force, a slope angle, a motor rotating speed and a vehicle mass estimation value, calculating an optimal recovery current through a Kalman filter, and injecting the recovery current into a battery pack by adopting a bidirectional Buck-Boost circuit; and the safety cooperative controller executes a hierarchical protection strategy, and a data bus is connected with each module to realize data interaction. Therefore, the problems that in the prior art, an electric scooter is insufficient in battery endurance, low in energy recovery efficiency, weak in impact resistance, poor in collaboration and the like are solved.

The invention discloses a battery pack equalization control method and system based on multidimensional state mapping, and the method comprises the steps: obtaining terminal voltage data, working current data and surface temperature data of each single battery in a target battery pack; calculating an ohm internal resistance value and a polarization impedance value of each single battery; calculating an impedance growth rate; according to the impedance growth rate and the surface temperature data, a health state value is determined, and an aging weighting coefficient is determined; determining a polarization safety coefficient of each single battery based on the polarization impedance value; calculating a state-of-charge value of each single battery in the target battery pack, and determining a balance demand deviation degree; determining a basic equalization duty ratio of each single battery according to the equalization demand deviation degree; correcting the basic balance duty ratio to generate a target pulse width modulation duty ratio; and according to the target pulse width modulation duty ratio, controlling equalization circuits connected to the two ends of each single battery to be switched on. The battery pack equalization control efficiency is improved.

The invention relates to the technical field of lithium battery charging under photovoltaic panel power supply, in particular to a Buck-Boost lithium battery intelligent charging method based on ML-MPPT and dynamic reference voltage regulation, and the method comprises the steps: dividing a charging stage into a trickle charging stage, a constant-current charging stage and a constant-voltage charging stage according to the voltage of a lithium battery; the method comprises the following steps: acquiring environment temperature, solar illuminance and maximum power point voltage data in a constant current stage, preprocessing the data, training a maximum power point voltage prediction machine learning model, distilling the model to obtain a compression model, and deploying the compression model on a microcontroller; real-time environment data is input into the model to predict and obtain the maximum power point voltage as the reference voltage, the output voltage of the photovoltaic panel is sampled, and the input voltage of the Buck-Boost circuit is controlled by using the innovative PWM control system, that is, the duty ratio of PWM pulses is controlled through the microcontroller, the input impedance of the Buck-Boost circuit is adjusted, and the output voltage of the Buck-Boost circuit is adjusted. The output voltage of the photovoltaic panel, namely the input voltage of the switching power supply, is adjusted to the maximum power point voltage according to environmental conditions; and dynamically switching the lithium battery in different charging stages according to the battery state and the input power. The method integrates machine learning into prediction of the maximum power point voltage, and is suitable for an intelligent charging scene of the lithium battery under photovoltaic power supply.

An improved BA-P&O hybrid algorithm based MPPT power supply control method for a satellite, comprising: a solar cell array regulates bus voltage by means of a DC-DC unit to supply power to a load; a storage battery is connected to a bus by means of a diode to supply power to the load; a bat algorithm iteration stage and a perturbation observation stage are used for tracking the maximum power of the solar cell array when the solar cell array and the storage battery supply power together; a bus voltage regulation stage is used for maintaining the bus voltage stable when the solar cell array supplies power independently, and determining the update direction of the current duty ratio on the basis of the current bus voltage sampling value; and the three stages jump to each other on the basis of set conditions. The present invention is used for MPPT power supply control.

The invention discloses a fork type mobile robot power distribution unit dynamic distribution control method and system, and relates to the technical field of intelligent robots, and the method comprises the steps: arranging sensors at a robot PDU input end and each output channel, collecting an operation data set in real time, and carrying out the preprocessing to form a dynamic feature data set; the main control microcontroller carries out power response analysis and evaluates a channel response state based on the dynamic characteristic data set, generates a preliminary power distribution instruction, calculates a target current MI during preliminary power distribution, carries out thermal stress analysis, and constructs a thermal stress identification index Htt to carry out thermal accumulation risk evaluation; when a heat accumulation risk exists, calculating a channel target current MII when the secondary power supply is distributed, and adjusting the duty ratio of an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) switch to carry out heat suppression regulation and control; and after the distribution is completed, calculating an energy utilization rate Nsys and executing energy efficiency state evaluation. According to the method, adaptive distribution and safe operation management of the multi-channel power supply of the robot are realized.

The invention discloses a server heat dissipation regulation and control method, device and equipment and a medium, relates to the technical field of computers, is applied to a management controller, and comprises the steps that whether the power panel fan rotating speed of each in-place power panel of a server conforms to a preset fan duty ratio or not is judged; if yes, performing heat dissipation area division on the server based on a power panel fan and a mainboard fan to obtain a plurality of server heat dissipation areas; collecting part temperatures of corresponding server parts in the plurality of server heat dissipation areas, and calculating target fan rotating speeds of a power panel fan and a mainboard fan based on the part temperatures, so as to perform heat dissipation regulation and control on the server heat dissipation areas according to the target fan rotating speeds; and if the abnormal fan which does not accord with the abnormal fan exists, increasing the fan rotating speed of the target mainboard fan of the abnormal heat dissipation area corresponding to the abnormal fan so as to perform heat dissipation regulation and control on the abnormal heat dissipation area. Therefore, cooperative regulation and control of the mainboard fan and the power panel fan can be realized through the management controller, so that the heat dissipation effect of the server is improved.

The invention relates to the technical field of electronics, and discloses a boost circuit control method and device, computer equipment and a storage medium, and the method comprises the steps: detecting a state change event in a boost circuit; calculating a voltage difference value between the front-end voltage value and the rear-end voltage value in the booster circuit, and determining a corresponding target control strategy based on the state change event and the voltage difference value, the target control strategy at least comprises a step of determining a corresponding target voltage value and a feed-forward current value based on vehicle driving parameters and working condition parameters of a load motor so as to execute voltage regulation, or a step of determining a corresponding feed-forward duty ratio based on a rear end voltage value of a booster circuit so as to execute voltage regulation; and executing corresponding control operation on the booster circuit according to the target control strategy. The problems that in the prior art, due to the fact that a control strategy of a booster circuit is fixed, and a state change event and voltage difference value dynamic adjustment are not combined, voltage adjustment response lags behind, and stability is insufficient are solved.

A DC / DC converter includes a converter stage to receive an input voltage and to provide an output voltage from the input voltage in accordance with a modulated drive signal. The converter stage further provides a feedback voltage representing the output voltage. A controller circuit includes an error amplifier to receive the feedback voltage and a reference voltage and to provide an error signal based on the feedback voltage and the reference voltage. A PWM modulator receives a clock signal and the error signal and generates a modulated signal based on the clock signal and the error signal, and a logic circuit receives the modulated signal and generates the drive signal for the converter stage based on the modulated signal so that the drive signal has the same duty cycle as the modulated signal, when the duty cycle of the modulated signal is not smaller than a minimum duty cycle value.

The invention relates to a circuit arrangement (1) for multi-zone heating operation, comprising: a plurality of heating wires (2, 2 '), which can be supplied in parallel by a heating voltage, for heating a touch surface (19) comprising a plurality of zones (20, 20'); wherein a respective heating wire (2, 2 ') is associated with a zone (20, 20'); at least one first switching element (3a, 3a ') for each heating wire (2, 2'), which is coupled between the heating wire (2, 2 ') and one of the two different heating potentials (VH +, VH-) of the heating voltage in such a way that, in a heating mode, a heating current is applied to the respective heating wire (2, 2') in the conducting state of the first switching element (3a, 3a '), and interrupting the heating current in the OFF state of the first switching element (3a, 3a '); a control circuit (12, 6a, 6a ', 6b, 6b') configured to generate, for each heating wire (2, 2 '), individual pulse width modulated first control signals (ST1, ST1') to switch the first switching elements (3a, 3a ') between an on state and an off state, respectively, the individual pulse width modulated first control signals being applied to first control terminals (Ga, G'a) of the first switching elements (3a, 3a'), respectively; wherein the control circuits (12, 6a, 6a ', 6b, 6b') are further designed to apply a respective associated heating current to a plurality of heating wires (2, 2 ') in a common heating stage in parallel, in an overlapping manner and / or in an alternating manner, and wherein at least two of the first control signals (ST1, ST1') differ in terms of their duty cycles.

The invention discloses a system for improving multi-series parallel power generation of photovoltaic cells, and relates to the technical field of photovoltaic power supply, the system comprises photovoltaic panels, photovoltaic optimizers, a photovoltaic gateway and an inverter, the power output of a photovoltaic array is optimized through a multi-stage cooperative control strategy, each photovoltaic panel is connected with an independent photovoltaic optimizer, and the photovoltaic panels are connected with the photovoltaic gateways. A working point is dynamically adjusted by adopting an MPPT algorithm, real-time data interaction with a photovoltaic gateway is carried out in a wireless or wired communication mode, the photovoltaic gateway automatically detects open-circuit voltage differences of parallel strings, dynamically adjusts the MPPT voltage range of each string and ensures the overlapping proportion of output voltages, the photovoltaic gateway monitors the duty ratio change of the strings, and when shielding is detected, the photovoltaic gateway is switched on and switched off. The MPPT parameters of the affected string are automatically adjusted, and the generating capacity of the system is improved.

The invention relates to an aero-engine main fuel pump regulator parameter swing global closed-loop control method. The problem that at present, parameter swing faults can only be detected through engine test run is solved. According to statistical analysis of test data of an aero-engine, the rotating speed n2, P2 air pressure, S1 duty ratio and S8 duty ratio parameters of a main fuel pump regulator are controlled through a PID controller on a main fuel pump regulator performance tester under the conditions of simulating different accelerator handle angles and different temperature instruction pressures, so that actual values of follow-up piston displacement, alpha1 and alpha2 parameters are close to expected values, and the actual values of the follow-up piston displacement, alpha1 and alpha2 parameters are close to expected values. And global closed-loop control of the rotating speed and the guide vane angle is realized. The global closed-loop controller comprises an analog sampling module, an analog voltage control module, a signal control module, an upper computer module, a server module, a power supply module, an MCU module and a sensor module. According to the invention, the detection of the aero-engine parameter swing fault on the main fuel pump regulator performance tester is realized, and the occurrence of the parameter swing fault is effectively suppressed.

The invention relates to the technical field of automatic control, in particular to a comprehensive automatic control method with a redundant fault-tolerant function, which comprises the following steps of: acquiring vibration data by a three-axis sensor, extracting characteristic parameters by combining with angular displacement pulse, evaluating modal quality by K-means clustering, triggering an abnormal identifier when a deformation gradient exceeds a threshold value, and performing fault tolerance. When harmonic distortion exceeds 15%, redundant channels are switched, a characteristic is fused to calculate a power factor, a phase switching loop is carried out, a PWM duty ratio is adjusted in three intervals, regression correction is carried out to generate a braking curve, verification execution is carried out, and corrugated roller machine redundant channel switching and parameter heavy loading are executed. According to the method, characteristic parameter clustering division mode evaluation quality, deformation correlation abnormity identification, harmonic monitoring dynamic switching path stable data flow, power factor calculation through a distortion rate and phase switching loop are constructed through combination of three-axis vibration and angular displacement, the PWM duty ratio is adjusted according to the power factor to improve the precision, and a vibration-mode-redundancy closed-loop system is constructed. And state identification and energy efficiency improvement are realized.

The invention relates to the technical field of air door motor control, and discloses an air door motor control method and system based on current detection, and the method comprises the steps: carrying out the single-phase current signal collection of an air door motor system, and obtaining a current change signal in the opening and closing process of an air door; carrying out FFT (Fast Fourier Transform) and wavelet decomposition processing on the current change signal to obtain a current characteristic spectrum component and a time domain characteristic; processing the current characteristic frequency spectrum component and the time domain characteristic to obtain an air door load current characteristic; iterative learning control is executed, and air door rotating speed control parameters are generated; the PWM duty ratio is calculated, and air door motor driving pulses are generated; according to the air door motor control method, a complete air door motor control protection mechanism is established, abnormal conditions such as stalling can be detected and coped with in time, the safety of an air door motor system is improved, and the service life of the air door motor system is prolonged.

The invention relates to an accelerator motor control method and system, and the method comprises the steps: obtaining a target rotating speed, obtaining a stay wire position according to a pre-stored rotating speed-stay wire position mapping table, and controlling the output of an accelerator motor based on the stay wire position; wherein the rotating speed-stay wire position mapping table is determined through pre-calibration, and the method comprises the following steps that an accelerator motor is controlled to loosen a stay wire to reduce the rotating speed of an engine to an initial value; controlling the accelerator motor to tighten the stay wire, enabling the rotating speed of the engine to gradually approach the set target rotating speed, and adjusting the PWM step duty ratio of the accelerator motor by comparing the error between the actual rotating speed of the engine and the target rotating speed; the error is within a set range and lasts for set time, the current engine speed and the PWM step duty ratio of the accelerator motor are stored, a set of calibrated mapping relation between the rotating speed and the stay wire position is obtained, and the rotating speed-stay wire position mapping table is updated; and repeatedly executing the step until the PWM step size duty ratio of the accelerator motor corresponding to all the target rotating speeds is obtained.

The invention discloses a three-level flexible excitation dynamic regulation and control method and system for a large-scale hydroelectric generating set, and relates to the technical field of flexible excitation control of the large-scale hydroelectric generating set, and the method comprises the steps: setting a DC bus voltage, and initializing a mapping relation between a capacitor voltage and an excitation output level; collecting operation parameters of a machine end, constructing a disturbance identification model and outputting a disturbance level; the excitation voltage output gear is set according to the disturbance level, the capacitor voltage difference is controlled, and dynamic voltage sharing is achieved by modulating the midpoint duty ratio. According to the method, through setting a bus target voltage and constructing excitation voltage output mapping, in combination with a disturbance level identification mechanism and a dynamic voltage-sharing strategy, closed-loop linkage of disturbance perception-voltage regulation-voltage difference control is realized. According to the method, the identification precision of the system on light disturbance and strong disturbance is effectively improved, the voltage stability and capacitance symmetry of the excitation system are enhanced, the overshoot risk is reduced, and the control robustness and safety of the system under extreme working conditions are improved.

The invention relates to a motor control technology, and discloses a current sampling method of a DC brush motor, electromechanical equipment and a storage medium, and the method comprises the steps: configuring a plurality of sampling points in a single carrier period of a PWM signal; controlling the started DC brush motor to operate based on the configured PWM signal; carrying out multi-point sampling of carrier period synchronization on the motor current based on an ADC (Analog to Digital Converter) sensor; automatically storing the sampled data into a buffer area based on DMA (Direct Memory Access); when it is detected that the buffer area is full, sampling interruption is triggered, and current data of the buffer area are read for filtering processing; the filtered current data are input into a current loop PID controller, and the duty ratio of a PWM signal is adjusted; and based on the adjusted PWM signal, returning to execute the step of controlling the started DC brush motor to operate based on the configured PWM signal. The invention further discloses a control device. The invention aims to improve the current sampling precision of the DC brush motor, and further improve the control response speed and stability of the system.

A multi-phase voltage regulator circuit applied in a multi-phase power converter is provided. The multi-phase voltage regulator circuit comprises multiple comparison circuits. The comparison circuits are coupled to a power output stage circuit and configured to generate multiple control signals The power output stage circuit generates multiple output currents according to the control signals. Each of the comparison circuits comprises a comparator and a correction conversion circuit. The comparator is configured to receive a compensation signal and a reference signal, and receive a correction signal through a first correction terminal and to adjust a duty cycle of a corresponding one of the control signals according to the correction signal. The correction conversion circuit is configured to generate a correction signal according to an error current. The error current represents a difference between a current threshold value and a corresponding output current for the corresponding phase.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and / or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

The invention discloses a thermal equipment water temperature control method based on a relaxation iteration PID algorithm, and aims to solve the problems that overshoot is easy to occur when a set value suddenly changes, and integral saturation and noise sensitivity are easy to cause by integral item accumulated errors in traditional PID control. The method comprises the following steps: calculating a current error e (t) = Tset (t)-Tmeas (t); a relaxation factor is introduced to dynamically adjust PID output increment, and the relaxation factor is adjusted according to a set value change rate in a grading manner; the accumulative control quantity is limited within the duty ratio range of 0-100%; and when the error absolute value is greater than 2 DEG C, freezing an integral term to avoid overshoot. According to the method, overshoot is effectively suppressed by setting a relaxation factor, differential terms are improved to reduce noise interference, and integral terms are managed in a partitioned manner to improve stability. Compared with a traditional PID control method, the method has the advantages that overshoot can be effectively restrained, the adjusting time is shortened, and the method is suitable for an industrial control system.

The invention provides an accurate temperature control method for micro LED chip welding. The method comprises the steps that the duty ratio of PWM is preset, and the laser switching time of a laser is modulated; and in each PID control period, according to the difference value between the real-time temperature of the light spot processing area and the target temperature range, the power of a laser emitting the light spot is adjusted through PID control, so that the real-time temperature of the light spot processing area is adjusted to be within the target temperature range. According to the invention, the PWM is used for periodically adjusting the laser switching time of the laser and is combined with the temperature control of the PID, so that the temperature control performance of the PID can be improved, the board burning is avoided, and the PID temperature control curve is smoother; and the chips with large and small sizes are compatible, and the laser does not need to be replaced or customized.

The present invention discloses an AC voltage regulating device and a control method, comprising input terminals (Ui1, Ui2) connected to a power grid, an input capacitor (3), an upper bridge arm (1), a lower bridge arm (2), an absorption module (4), and a discharge module (14). By adjusting the PWM duty cycle of the switch devices in the upper bridge arm (1) and the lower bridge arm (2), the total output voltage of Uo1 and Uo2 can be controlled to achieve a preset voltage value. The AC voltage regulating device and the control method of the present invention can realize direct voltage stabilization of AC power supply, significantly reduce the circuit complexity and device cost compared with the existing technology, and can effectively stabilize the power supply voltage of the power grid. The device has the advantages of fast response speed, low cost, simple control method, high reliability, convenient maintenance, and high efficiency.