149 results about "Dc bus voltage" patented technology

The utility model relates to a kind of compressor inverter overcurrent protection circuit and air conditioner, belong to air conditioning technical field, including rectifier unit, sampling resistance, main control chip, overcurrent protection control switch, fault state self-locking maintenance switch, operational amplifier and voltage comparator.Sampling resistance gathers DC bus voltage signal, after amplification by operational amplifier, it is transmitted to the analog-digital conversion pin and voltage comparator of main control chip.Signal is compared with preset threshold by voltage comparator, low level is output when over threshold, makes overcurrent protection control switch open, rectifier unit is disabled;While fault state self-locking maintenance switch is turned on, and fault pin is locked as low level, realizes overcurrent protection and self-locking.The circuit cooperates by hardware and software, quickly responds overcurrent fault and prevents false restart, improves the security and reliability of air conditioning system.

According to one embodiment of this application, a testing method for a braking unit is provided. The braking unit to be tested is connected to the DC bus of a frequency converter, and the frequency converter is connected to a motor. The motor is driven to accelerate to a preset speed. An emergency stop operation is performed on the motor, causing the motor to generate energy feedback to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise. By monitoring the DC bus voltage, when the DC bus voltage rises to a preset threshold, the braking unit is triggered to operate, consuming the feedback energy in the braking resistor of the braking unit. By adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit is controlled, thereby enabling the testing of different braking powers of the braking unit to be tested. This method improves the accuracy and versatility of the test and is more user-friendly. This application also provides a testing system for a braking unit.

This invention discloses a method and device for bus capacitor energy storage active disturbance rejection voltage regulation control of a multiphase permanent magnet generator. The method establishes a bus capacitor energy balance equation based on the square of the DC bus voltage, and then restructures the equation into a linear active disturbance rejection standard form. A second-order linear extended state observer is designed to estimate the square of the DC bus voltage and the total disturbance in real time. A state feedback control law is designed based on the disturbance compensation principle to generate a virtual control quantity and obtain the linear active disturbance rejection current. The load current is low-pass filtered, and the feedforward current is calculated based on the power balance relationship and superimposed on the linear active disturbance rejection current to obtain the q-axis current reference. This reference current is then limited and subjected to anti-integral saturation processing before output. The difference between the reference current and the q-axis current is subjected to closed-loop control, and the resulting q-axis voltage is used as the generator voltage setpoint. All setpoint voltages are converted into the duty cycle of each phase for output. This invention achieves rapid and stable control of the bus voltage, with strong disturbance rejection capability and rapid dynamic response.

This invention provides a miniature general-purpose electrical control device and method, including a power adapter module, a PLC programming control unit, a central coordination controller, and an integrated control module. The invention acquires input power signals, identifies their type and amplitude range, and generates electrical state identifiers. Based on these identifiers, it selects the corresponding rectifier topology, converting the input power into a stable intermediate DC bus voltage, forming a reconfigurable DC energy pool. It acquires multi-channel load state data through miniature sensor nodes, generating a multi-dimensional load feature vector. Using an improved fuzzy PID coordination controller, it integrates load characteristics with a preset channel priority strategy, calculates energy demand weights, and generates a dynamic power allocation matrix. Based on this matrix, it adjusts the operating mode and power flow of the bidirectional DC / DC converter. This invention significantly improves power adaptability and energy utilization in multi-input, multi-output power supply scenarios, effectively addressing complex operating conditions such as grid fluctuations and uneven load distribution.

This application relates to a self-starting control method for a variable-speed pumped-storage unit and the variable-speed pumped-storage unit itself. The self-starting control method, when the stator is not connected to the grid, controls each power branch to pre-charge to establish the DC bus voltage; connects a portion of the power branches to the rotor and another portion to the stator; based on the rotor position relative to the stator, modulates the excitation current of each power branch to drive the rotor to smoothly increase speed; when the rotor reaches a preset speed, the power branches are connected to the rotor. The self-starting control method for a variable-speed pumped-storage unit provided in this application, by omitting the SFC (Self-Fuel Collector) and reusing the advantages of a multi-branch parallel converter topology, achieves SFC-less starting, solving the problems of high cost, low utilization, and complex excitation systems caused by the requirement of a separate SFC for traditional pumped-storage units. This simplifies the system structure, reduces costs, and improves operational reliability.

This invention discloses a transient control method for a wind turbine grid-connected system that utilizes a reverse energy absorption branch, relating to the field of new energy technology. The energy-consuming branch is connected in parallel to the DC bus capacitor. The grid connection point voltage and DC bus voltage of the wind turbine grid-connected system are acquired. When the grid connection point voltage reaches a preset condition, a reference value for the d-axis current of the grid-side converter is calculated based on the grid connection point voltage and the voltage of the DC bus capacitor. Based on the reference value, the active power state of the grid-side converter is switched to an active power absorption state, allowing the DC bus capacitor to store electrical energy and raise the voltage. When the voltage of the DC bus capacitor is greater than the threshold voltage of the transistor, the transistor is controlled to be in the conducting state. Through this technical solution, the direction of energy flow on the DC bus between the turbine-side converter and the grid-side converter can be changed. Furthermore, by consuming excess energy through resistance, wind turbine output oscillations and DC-side overvoltage can be suppressed, and the synchronous stability of the wind turbine grid-connected system can be improved.

This application belongs to the field of power electronics and automatic control technology, and relates to a power supply smooth switching control method for suppressing DC bus voltage surges. It solves the problem of DC bus voltage surges caused by potential changes during primary / standby power supply switching, including: dynamically matching the standby power supply output to the primary power supply voltage and reserving a voltage difference margin through voltage closed-loop feedback; initiating switching when a primary power supply fault is detected or the bus voltage drop rate exceeds a threshold; utilizing controlled current injection into the MOSFET gate to bring it into the Miller plateau region and allowing it to remain in the linear operating region for a preset transition period; controlling the MOSFET drain-source equivalent resistance to continuously decrease according to an S-shaped function to absorb transient energy; and locking the fully conducting state to complete seamless switching when the drain-source voltage difference approaches zero. This method effectively eliminates high-frequency oscillations, achieves microsecond-level potential transitions, significantly improves system reliability and response speed, and is suitable for high-reliability power supply scenarios with stringent "zero-inductive switching" requirements.

Solid-state circuit breakers (SSCBs) have been witnessing an impressive progress with the aid of wide bandgap (WBG) devices such as silicon carbide (SiC) MOSFETs. Along with obtaining high efficiency as the result of low on-state resistance, response times have been gaining remarkable achievements in microseconds range. Not only that, the reported successes in control and gate drivers design and incorporating fault detection / location techniques in SSCBs are promising. A MOV-resistive capacitive switch (MOV-RCS) snubber for solid state circuit breakers addresses the following: 1) the MOV degradation issue in DCCBs is solved, 2) the maximum allowable DC bus voltage on DCCBs is extended. The solid state circuit breaker and an active clamping snubber includes a first circuit including a fault current bypass based solid state breaker for low voltage direct current systems.

This invention discloses a flexible low-frequency-flexible DC hybrid power transmission system and its control method. The hybrid power transmission system of this invention includes a receiving-end converter station, a low-frequency AC renewable energy power station, and a high-frequency DC renewable energy power station. The power conversion unit of the receiving-end converter station adopts a modular design. Each power module is combined in series / parallel to form the power frequency AC, low-frequency AC, and high-voltage DC ports of the converter station. Each port is connected to the power frequency main grid, the low-frequency AC port, and the DC renewable energy power station through transmission lines, respectively. The receiving-end converter station achieves voltage stability of the low-frequency AC port and the high-voltage DC port, sinusoidal current of the power frequency AC port, and DC bus voltage stability of each power module through multi-level control at the system level, bridge arm level, and module level. This invention achieves coordinated operation of flexible low-frequency and flexible DC power transmission modes, is suitable for efficient transmission from renewable energy power stations at different distances, and realizes integrated operation of different types of converter stations.

The present application relates to the field of power system control and power electronic energy storage technology, in particular to a generator set transient power compensation system and method thereof, the method comprising: collecting stator voltage, stator current, rotor angular velocity, power angle and DC bus voltage, and mapping into a generalized state vector; constructing a port-controlled Hamilton system model containing an initial interconnection matrix and an initial damping matrix based on preset physical parameters and obtaining a Hamilton energy function; taking partial derivative of the Hamilton energy function with respect to the generalized state vector, calculating an energy gradient vector, dynamically reconstructing a virtual interconnection matrix and a virtual damping matrix, analyzing control input and converting into a duty cycle command to send to an energy storage converter to perform transient power compensation; the system comprises a data acquisition module, a Hamilton energy controller and an energy storage converter; faster transient recovery, lower mechanical stress and more stable closed-loop response can be achieved.

This invention discloses a control method and related components for an on-board charger, relating to the field of electric vehicles. When the on-board charger operates in V2L mode, the DC bus voltage of the on-board charger is acquired. To prevent the load from failing to start or stop normally due to excessively low DC bus voltage, when the DC bus voltage falls below a preset value, the AC output voltage of the on-board charger is actively reduced to a first AC output target voltage, thereby reducing the power demand of the load and allowing the on-board charger to maintain its output characteristics. After the AC output voltage of the on-board charger decreases and a preset derating time has elapsed, the DC bus voltage of the on-board charger gradually recovers. At this point, the AC output voltage of the on-board charger is then increased to a second AC output target voltage to ensure the normal power demand of the load.

The present application relates to the technical fields of energy-saving control, in particular to a three-rail conveyor energy-saving braking control method and system, comprising the following steps: obtaining resistance and parameter splicing to generate an electromagnetic resistance matrix, calculating a parameter change rate to extract resistance to generate a braking period resistance vector, comparing node incremental trends to collect DC bus voltage to generate a monitoring sequence, differentiating to extract an ascending gradient and optimizing to obtain a high-frequency pulse duty cycle, using the duty cycle to generate a modulation signal to inject into an inverter pin, adjusting the feed current to build an energy recovery closed loop. In the present application, the system kinetic energy dissipated as heat energy during braking is efficiently converted into electrical energy for storage and reuse, the inverter pin driving timing is dynamically self-adapted to control the energy storage capacitor charge release and transfer rate, effectively avoiding the energy one-way dissipation and component severe wear caused by pure mechanical friction braking mode, and realizing precise state monitoring and recovery closed loop control of system energy in the entire braking process.

The application provides a variable driving parameter silicon carbide MOSFET active driving method, circuit and device. The active driving method comprises: in the on process, a power supply is controlled to apply a first weak driving level in a first time period and a first strong driving level in other time periods, the starting time of the first time period is the time when the silicon carbide MOSFET enters the Miller platform, and the ending time is the time when the drain current reaches the current overshoot peak value; in the judgment process, the power supply is controlled to apply a second weak driving level in a third time period and a second strong driving level in other time periods, the starting time of the third time period is the time when the drain-source voltage is equal to the DC bus voltage, and the ending time is the time when the drain-source voltage reaches the voltage overshoot peak value. The method has good versatility and high engineering application value, reduces the additional switching loss caused by weak driving, maintains high switching speed while ensuring the overshoot suppression effect, and thus realizes a better compromise between overshoot, loss and switching time.

This application discloses a method and apparatus for three-phase imbalance and harmonic compensation, relating to the field of power distribution network control technology. It synchronously collects three-phase voltage on the grid side, three-phase current on the load side, and DC bus voltage at multiple consecutive moments from an active power control device. Based on this, a time-series data sequence is constructed and input into a pre-trained gated cyclic unit network to obtain the initial compensation current. The DC bus current compensation component is determined based on the DC bus voltage and its reference value. The loss current component is estimated based on the current switching state function and output current of the active power control device, and the target compensation current is determined accordingly. A current tracking error vector is determined based on the target compensation current and the actual compensation current. A switching drive signal is generated based on the current tracking error vector. Under the control of the switching drive signal, the target compensation current is output, thereby achieving the mitigation of load harmonics, reactive power, and three-phase imbalance components.

The application discloses a kind of monitoring system and method for safety of induced electric high voltage launch, it is related to geophysical exploration instrument technical field, the system includes: data acquisition module, DC relay, control module and monitoring end;Data acquisition module, DC relay and monitoring end are connected with control module;Data acquisition module is used to calculate the ground resistance in the induced electric launch loop of target induced electric transmitter in real time, and the ground resistance of real-time calculation is sent to control module;Control module is used to send the ground resistance received in real time to monitoring end, and when ground resistance is greater than set resistance threshold, the DC bus voltage of target induced electric transmitter is disconnected by controlling DC relay, and open-circuit fault information is sent to monitoring end by wireless communication.The application realizes the real-time safety monitoring of high induced electric transmitter, and improves production safety.

This invention relates to the field of battery control technology and discloses a sodium-ion battery charging and discharging control system and method, including a peripheral access interface, a multi-machine parallel communication module, a sodium-ion battery pack, and an inverter. The invention uses a control module to parse type identification data. When the parsed type identification data indicates that the connected energy storage medium is a sodium-ion battery pack, the control module calls a preset low-voltage discharge model. The control module unlocks the discharge cutoff voltage threshold set by the conventional discharge model and locks the lower limit of the discharge cutoff voltage to the deep over-discharge cutoff threshold. During the discharge state of the sodium-ion battery pack, the data sampling unit collects the terminal voltage data of the sodium-ion battery pack. When the terminal voltage data is within the range of the discharge cutoff voltage threshold and the deep over-discharge cutoff threshold, the control module generates a dynamic duty cycle command. The bidirectional DC-DC converter circuit receives the dynamic duty cycle command and maintains the DC bus voltage data constant.

This application relates to an automatic startup method for an off-grid energy storage system. The method includes: detecting that the DC output voltage of the photovoltaic array reaches a first preset threshold, charging the supercapacitor bank; when the voltage rises to a second preset threshold, connecting the charged supercapacitor bank to power the system's main controller and battery management system, and sending a startup command to the photovoltaic MPPT DC-DC module to charge its DC-side bus capacitor. The DC bus voltage reaches the startup threshold of the energy storage converter (PCS). After the PCS completes its internal self-test and meets the startup conditions, it performs independent inversion to establish a stable AC output voltage. At this time, the main system power supply is established. The automatic switching circuit detects that the main system power supply is valid and seamlessly switches the power supply from the startup power supply to the main system power supply. This process allows the off-grid energy storage system to autonomously recover from power failure using only photovoltaic energy when there is no external power supply or manual operation, improving system reliability, economy, and environmental adaptability.

This invention discloses a control method, apparatus, and device for an ANPC-type three-level inverter, including a three-level inverter circuit. The method includes: firstly, determining whether the inverter is switching from a first mode to a second mode; calculating the collector voltage value based on the DC bus voltage, the bridge arm current of the inverter circuit, a preset stray inductance, and a voltage safety margin; if the collector voltage value is less than or equal to a preset voltage value, and the first mode and the second mode meet a first preset condition, and the junction temperature of the outer transistor is greater than or equal to a first preset temperature, and / or the junction temperature of the clamping transistor connected to the outer transistor is greater than or equal to a second preset temperature, then the inner transistor is turned off and another clamping transistor is turned on; the first preset condition includes the first mode outputting a positive potential, the second mode outputting a zero potential, and the output current being greater than zero, or the first mode outputting a negative potential, the second mode outputting a zero potential, and the output current being less than zero. This method evens out the losses of transistors with higher junction temperatures to the inner transistor, preventing transistor damage.

The application discloses an elevator software electronic simulation test system, the test object includes elevator logic control software and elevator drive software, wherein data exchange is carried out between the elevator logic control software and the elevator drive software, the elevator simulation test device includes an elevator logic simulation subsystem and a motor drive simulation subsystem, wherein the motor drive simulation subsystem includes a PWM sampling module, a frequency converter DC bus voltage estimation module, a motor power estimation module, an elevator load simulation module, a motor simulation module, an encoder simulation module and other output interface modules and the like. The simulation test system collects the data of the PWM output waveform of the elevator drive software, the data of I / O interfaces such as a brake resistor and a fan, simulates the running state of the elevator and the motor in a pure software mode, realizes the simulation of the motor rotating speed, position and current and the like, connects the simulation result into the elevator drive software, and thus realizes the test on the elevator drive software.

The application discloses a point balance and circulating current suppression control method, device, equipment and medium, and relates to the technical field of power electronic control. The application is applied to a first three-level converter and a second three-level converter in parallel. Three-phase currents and a DC bus voltage are collected in real time, dq-axis current closed-loop control is performed, and o-axis current closed-loop control is performed on the second three-level converter. Based on a given voltage in a three-phase stationary coordinate system, midpoint voltage balance control operation is performed, and a compensation control voltage is calculated. The compensation voltage is limited by a difference limiting strategy, is superimposed into the given control voltage, and finally control signals are generated through pulse width modulation. Through the active injection of o-axis control components and the optimized difference limiting midpoint balance algorithm, the application effectively solves the circulating current problem and the midpoint potential imbalance problem in the parallel system, and improves the reliability of the system.

This invention belongs to the field of microgrid inertia simulation technology. It proposes a distributed inertia simulation method and system for hybrid AC / DC microgrids. The system is built around a closed-loop logic of "frequency information without communication transmission - adaptive high-precision sensing - nonlinear inertia accurate output - IPSO optimized multi-topology aggregation - overall system stable control". A reference value is constructed by superimposing an AC disturbance signal onto the rated voltage of the DC bus. The average value of this disturbance signal is zero, so the steady-state DC component of the DC bus voltage is not changed, keeping it stable near the rated value. The DC bus capacitor only serves as a medium for transmitting frequency information and does not participate in energy storage and release. This solves the voltage deviation problem caused by energy release and absorption in traditional capacitor inertia simulation methods, avoids the risk of overvoltage / undervoltage protection actions and system instability caused by this, and ensures the stability of system operation.

The invention discloses an energy consumption device control method and system suitable for symmetric monopole-bipolar direct current, which are applied to the technical field of direct current control, and the method comprises the steps: obtaining the electrical quantity data of a target direct current system; performing abrupt change analysis on the electrical quantity data, and determining a fault event signal based on an obtained analysis result; based on the fault event signal, determining an energy consumption branch input by the target direct current system; a corresponding energy consumption branch is reconstructed, a reconstruction result is executed, and the voltage of the direct-current bus, the current of the sound pole converter and the temperature of the energy consumption resistor are obtained; processing by utilizing a multivariable decoupling control technology to obtain energy consumption power difference data; and based on the energy consumption power difference data, a cooperative control strategy is generated by adjusting an offshore wind plant in the target direct current system. According to the method provided by the invention, the technical problem that the transient stability of the system is influenced due to control target conflict caused by the fact that the independent action of the traditional energy consumption device is not deeply coordinated with other control structures of the direct current system can be solved.

The application discloses a hybrid energy storage system energy management method and system, and relates to the technical field of energy storage system energy management. The method comprises the following steps: collecting output currents of each energy storage converter and estimating physical link impedance values of each converter branch to a DC bus; constructing a physical link decoupling term and superimposing the physical link decoupling term into a droop control model to generate a preliminary voltage reference value; collecting output voltages of each energy storage converter after physical link decoupling, inputting the output voltages into a PI regulator respectively after being subtracted from a set DC bus voltage reference value, calculating a battery-side virtual voltage source compensation term and a super capacitor-side virtual voltage source compensation term, and performing second correction on the preliminary voltage reference value to obtain a final output voltage reference value; and sending the final output voltage reference value into a voltage-current double closed loop controller for modulation to generate a PWM driving signal, so as to control actions of each energy storage converter. The method eliminates high-frequency fluctuation components of the bus voltage under high-frequency and severe fluctuation of the load, and ensures stability of the bus voltage.

This invention discloses a flywheel-battery hybrid energy storage method and system for suppressing grid power oscillations, relating to the field of power system stability control technology. It includes: acquiring the real-time rotor speed of the flywheel energy storage unit; generating a first power command based on the deviation from a preset rated speed; determining whether the real-time rotor speed is within a preset speed range; if it exceeds the limit, generating a second power command to control the battery energy storage unit to charge and discharge at a constant power; if it is within the range, generating a third power command based on the DC bus voltage deviation; and controlling the battery to execute the commands based on priority arbitration logic, with the second power command having higher priority than the third power command. This invention addresses the problems of existing centralized control architectures heavily relying on complex communication, experiencing response delays, and batteries suffering from shallow charging and discharging and rapidly declining lifespan due to frequent tracking of power oscillations.

This disclosure provides a power control method, apparatus, electronic device, and storage medium. The charging circuit includes: acquiring the input voltage of a BOOST circuit within the power system during the current control cycle, and acquiring the change in the DC bus voltage during the current control cycle; the DC bus is connected to the output terminal of the BOOST circuit; determining a target operating state of the BOOST circuit in the next control cycle based on the input voltage and the bus voltage change; and controlling the BOOST circuit to switch to the target operating state in the next control cycle. In this embodiment, the output voltage of the BOOST circuit is adjusted to a dynamic voltage, adjusting the bus voltage according to the bus voltage change and the input voltage, thereby ensuring the system efficiency of the power system.

This application belongs to the field of DC bus voltage control, specifically disclosing a super-spiral sliding mode active disturbance rejection control method based on an RBF neural network, including the following steps: establishing a mathematical model of a bidirectional Buck / Boost circuit; designing an active disturbance rejection controller, which includes a tracking differentiator and an extended state observer; using an RBF neural network to dynamically optimize the gain parameters of the extended state observer in real time; constructing a super-spiral integral sliding mode controller to replace the nonlinear state error feedback loop in the active disturbance rejection controller; calculating a current reference signal based on the output signal of the tracking differentiator and the observation signal of the extended state observer through the super-spiral integral sliding mode controller; generating a drive signal based on the current reference signal to control the bidirectional Buck / Boost circuit to maintain the stability of the DC bus voltage. This application can effectively improve the stability and disturbance rejection capability of the DC microgrid bus voltage.

The application discloses a wind turbine generator unit variable flow system performance degradation identification method and related device, comprising: collecting the temperature of IGBT module in the variable flow system, the DC bus voltage, the output power harmonic distortion rate, and constructing a data set based on the same; performing data processing on the data set to obtain a processed data set; performing nonlinear feature extraction on the data set to obtain a dimension-reduced principal component score vector; constructing a hidden Markov model; and calculating the probability of the wind turbine generator unit variable flow system being in each degradation state based on the hidden Markov model and the dimension-reduced principal component score vector. The method and related device can realize performance degradation identification of the variable flow system, and have lower requirements on data quality.

This invention discloses a method for adjusting the operating mode of a floating multi-energy complementary power generation platform system. The method includes setting the wave energy generation unit to MEC mode; setting the photovoltaic power generation unit to MPPT mode; setting the grid-side inverter unit to current source mode (VOC control mode); setting the energy storage unit converter to power generation fluctuation smoothing mode, and switching the charging and discharging states of the energy storage unit through constant power control; setting the wave energy generation unit to MEC mode or shutdown operation mode; setting the photovoltaic power generation unit to MPPT mode or constant voltage control mode; setting the grid-side inverter unit to VF control mode; and setting the energy storage unit converter to DC bus voltage stabilization control mode. This invention reduces transmission losses while minimizing the power impact on the main grid during the grid-connected operation of the island microgrid based on the power generation platform, thus improving the system's operational reliability.

A method comprises: in an onboard charger of an electric vehicle, providing i) a direct current (DC) to DC stage including a dual-active bridge, and ii) a DC link capacitor having a DC bus voltage; and dynamically regulating the DC bus voltage to improve zero voltage switching (ZVS) in the onboard charger.

This invention relates to the field of composite energy storage control technology, and more particularly to a hierarchical collaborative control method for power-type and energy-type composite energy storage systems. The technical solution includes an upper power distribution control layer and a lower current tracking control layer. The composite energy storage system includes a superconducting energy storage system and an electrochemical energy storage system. The upper power distribution control layer includes the following steps: acquiring the DC bus voltage signal and calculating its deviation signal from the reference value. This invention reduces the online computational burden through event-triggered VMD and frequency domain feature preservation mechanisms, dynamically optimizes filter parameters using frequency domain features to achieve a reasonable division of labor between power-type and energy-type energy storage, and introduces a safety adjustment factor and an asymmetric MPC penalty term to actively suppress the risk of overcharging and over-discharging at the superconducting energy storage boundary. This significantly reduces the number of high-rate charge / discharge switching times for electrochemical energy storage while smoothing power fluctuations, extending its cycle life, and improving the system's robustness to measurement noise and operating condition changes.