5810 results about "Voltage source" patented technology

An example test station assembly of a cathodic protection monitoring assembly includes a face plate including a plurality of openings. In addition, the test station assembly includes a plurality of test posts to pass through the plurality of openings. Further, the test station assembly includes a plurality of electrically non-conductive identification indicators to connect to the plurality of test posts on the face plate. Each of the plurality of identification indicators including one or more identifying characteristics to identify a corresponding voltage source of a plurality of underground voltage sources associated with an at least partially buried structure, a cathodic protection system for the buried structure, or the cathodic protection monitoring assembly. Still further, the test station assembly includes a plurality of electrical conductors to electrically connect the plurality of test posts to the plurality of underground voltage sources.

The present application relates to a virtual synchronous control method and apparatus for an energy storage system, a device, and a storage medium. The method comprises: controlling an output voltage of a direct-current energy storage valve on the basis of an output electrical signal measurement value of a direct-current side of a voltage source converter and an output voltage reference value of the direct-current energy storage valve; further, controlling an output signal of an alternating-current side of the voltage source converter on the basis of a grid connection point electrical signal measurement value and a grid connection point electrical signal reference value of the voltage source converter. It can thus be seen that the embodiments of the present application implement a virtual synchronous control method independently controlling a voltage source converter and a direct-current energy storage valve in an energy storage system, so that the method can be applied to virtual synchronous control of a high-voltage direct-current direct-mounted energy storage system. In addition, by means of independently controlling the voltage source converter and the direct-current energy storage valve in the energy storage system, the voltage source converter does not need to be configured to take into account both direct-current side control and alternating-current side control, so that the complexity of a control loop of the voltage source converter can be simplified.

The invention belongs to the technical field of distributed energy storage control, and discloses an optimized operation method and system for a multi-network-constructed energy storage system, and the method comprises the steps: carrying out the equivalence of the multi-network-constructed energy storage system, and obtaining an equivalent energy storage system; wherein the equivalent energy storage system comprises an isomorphic network-following converter, an equivalent impedance R and an ideal voltage source which are sequentially connected in series; based on the equivalent energy storage system, obtaining a small signal stability boundary condition by adopting a Routh criterion; and taking the minimum operation cost as an objective function, solving the objective function under operation constraints including small signal stability boundary conditions, and obtaining J and D of each network construction type converter at different moments, so that each network construction type converter operates under the corresponding J and D. The method is suitable for optimized operation configuration of an energy storage system comprising a plurality of network following-constructing converters, and can effectively promote advantage complementation of renewable energy sources and energy storage, thereby improving system stability and operation economy.

The invention discloses an insulation detection method for an electric automobile, belongs to the technical field of high-voltage safety monitoring of the electric automobile, and solves the problem that the insulation detection precision is reduced due to electromagnetic interference, impedance fluctuation and capacitive effect coupling in a dynamic load switching process. According to the scheme, a test sequence of discrete frequency points is applied to a high-voltage system; measuring a response current value through a current sensor and calculating a ground distributed capacitance value; connecting a test voltage source between positive and negative electrodes of the high-voltage system through a coupling circuit; applying a first pulse signal during no-load, dynamically setting the width according to the capacitance value, measuring a first response current value, and calculating an initial insulation resistance value; a second pulse signal with the same parameter is applied in the load state window, a second response current value is measured, and differential filtering is carried out in combination with the initial value to eliminate load noise; and comparing the filtered insulation resistance value with a threshold value, and outputting a fault signal when the insulation resistance value is lower than the threshold value. The method is used for monitoring the insulation state of the high-voltage system in real time and accurately early warning faults.

The invention discloses a reconfiguration-based operation optimization method for a power distribution system containing a reconfigurable soft switch. The method comprises the following steps of: 1, constructing a self-energy-storage type reconfigurable intelligent soft switch topology based on asymmetric voltage source converter capacity and feeder line selection; 2, modeling is carried out on the self-energy-storage recombined intelligent soft switch; and 3, modeling the reconfiguration-based flexible power distribution system containing the reconfigurable soft switch, and obtaining an optimal operation strategy of the power distribution system by solving the optimization operation model. According to the invention, the multi-element controllable equipment of the power distribution system can be reasonably utilized to improve the utilization rate of the traditional multi-terminal intelligent soft switch to the capacity of the voltage source converter, and the maximum transmission power of the traditional multi-terminal intelligent soft switch can be improved, so that the operation loss of the power distribution system can be reduced, and the new energy consumption can be improved.

Described embodiments include a control circuit with a first comparator having a first comparator input receiving a first threshold voltage, and a second comparator input coupled to an output voltage terminal. A second comparator has a third comparator input receiving a second threshold voltage, and a fourth comparator input coupled to a current output terminal. A first logic circuit provides a true signal at its output responsive to a particular number of its inputs receiving a true input. A second logic circuit has inputs coupled to the first comparator output, and to the first logic output. A variable resistance circuit has an output coupled to a mode detection output. An amplifier has inputs coupled to the variable resistance circuit output, and a third reference voltage source. A duty cycle generation circuit provides a respective pulse width modulation (PWM) signal at each of its respective duty cycle outputs.

The invention relates to the technical field of field data acquisition, in particular to an on-line temperature self-compensation calibration method and circuit for a force measurement transmitter. The calibration method comprises the steps that a working strain gauge and a temperature compensation gauge are synchronously excited through a two-way precision constant current source, the working strain gauge and the temperature compensation gauge are consistent in material parameter and are located in the same temperature field, and output current values of the two-way precision constant current source are equal and are controlled by a high-precision reference voltage source and a sampling resistor in a closed-loop mode. According to the invention, differential signals of the working strain gauge and the temperature compensation gauge are decoupled in real time through double-path precise constant-current source excitation and synchronous ADC acquisition technologies, gradient compensation is carried out on the temperature change rate in combination with a dynamic weighting algorithm, a lag error of traditional fixed coefficient compensation in a transient temperature field is effectively eliminated, and the accuracy of temperature compensation is improved. And online self-compensation of the temperature drift of the strain gauge is realized.

The invention discloses a memristor-based signal detection circuit and method, a receiver and equipment, and relates to the field of wireless communication, a voltage source module of the circuit is connected with a voltage input end of a memristor array module, and a current source module is connected with a current input end of the memristor array module; the current output end of the memristor array module is connected with the reverse input end of the operational amplifier module and one end of the feedback resistor module, the other end of the feedback resistor module and the output end of the operational amplifier module are connected with the input end of the multiplier module, and the output end of the multiplier module is connected with one end of the resistor module. The voltage of the voltage source module is set according to the emission vector set; the current of the current source module is set according to the received radio frequency signal, and the conductance value of the memristor is set according to the channel matrix, so that a relatively low bit error rate of signal detection can be realized on the basis of greatly reducing calculation time and power consumption, and meanwhile, the requirement on programmable bit precision of the memristor is also reduced.

A plasma processing system includes a pulsed voltage source configured to generate a pulsed voltage waveform having a first frequency. The plasma processing system includes a radio frequency source configured to generate a radio frequency waveform having a second frequency that is higher than the first frequency. The plasma processing system includes a junction box enclosure electrically coupling the pulsed voltage source to a direct current conductor coupled to a substrate support and further electrically coupling the pulsed voltage source to a radio frequency conductor coupled to a radio frequency baseplate. The junction box enclosure includes a pulsed voltage filter circuit coupled between the radio frequency source and the radio frequency conductor and operable to filter the pulsed voltage waveform. The junction box enclosure further includes a radio frequency filter circuit coupled between the pulsed voltage source and the direct current conductor and operable to filter the radio frequency waveform.

A method and system for evaluating strength of a voltage source converter (VSC)-penetrated power grid based on voltage stiffness are provided. First data corresponding to a to-be-analyzed power grid is acquired in real time, and processed to generate a first admittance matrix corresponding to the to-be-analyzed power grid. The first admittance matrix is processed to generate device impedance data of each VSC and a second admittance matrix corresponding to the to-be-analyzed power grid. Rows and columns where a grid-forming VSC node and a rated alternating-current (AC) bus voltage grid-following VSC node are located are removed from the second admittance matrix to generate a third admittance matrix, which is processed to generate second data and third data corresponding to the VSC node. Strength evaluation data corresponding to the to-be-analyzed power grid is generated based on the third data in combination with the second data.

The invention discloses a power coupling-considered capacity ratio estimation method for a network-constructing / network-following multi-machine hybrid system, and the method comprises the steps: building a GFL-GFM hybrid system model, combining VSG power coupling small signal modeling and a dynamic relative gain matrix (DRGA), and quantifying the coupling strength of active / reactive power to output voltage; the frequency domain impedance characteristic of the GFM converter is simplified, and an ideal voltage source series equivalent reactance equivalent model is constructed; deriving an analytical relationship between a generalized short-circuit ratio (gSCR) and a capacity ratio based on the model, and generating a ratio formula in combination with engineering boundary sub-scenes to form a ratio range suitable for multiple scenes; for coupling time-varying characteristics, a closed-loop mechanism of'mixed mode-coupling sensing-correction calculation-execution feedback 'is constructed, and the ratio is dynamically adjusted. According to the method, coupling quantization and multi-machine coordination control are deeply fused, the problem that the external characteristic model precision and the multi-working-condition adaptability are difficult to consider under complex environment coupling is effectively solved, and the engineering applicability of the hybrid fan system is enhanced.

The invention provides a high-frequency circulating current calculation method for a motor simulator cascade coupling parallel structure, and the method comprises the following steps: building an equivalent decoupling circuit model of each branch in the cascade coupling parallel structure based on the voltage relation of each branch in the motor simulator cascade coupling parallel structure, wherein the equivalent decoupling circuit of each branch comprises an equivalent voltage source and an equivalent leakage inductor which are connected in series, and the equivalent leakage inductor is determined based on self-inductance and mutual inductance of a choking coil of each branch; a plurality of duty ratio intervals are divided between 0 and 1, and the number of the duty ratio intervals is equal to the number of the branches in the cascade coupling parallel structure; and using the equivalent decoupling circuit model to calculate the high-frequency circulation of each corresponding branch when the duty ratio of the modulation signal of the motor simulator is in each duty ratio interval. According to the method provided by the invention, the high-frequency circulating current of the cascade coupling parallel structure of the motor simulator can be accurately calculated, and effective support is provided for targeted design of a high-frequency circulating current suppression scheme.

The invention provides a method for setting virtual internal potential control parameters of a network-building type converter, and relates to the technical field of network-building type converters, and the method comprises the steps: S1, determining the virtual internal potential control parameters of the network-building type converter; s2, using an equivalent circuit method to generate a network-forming converter equivalent circuit; constructing an equivalent voltage source model of the network-forming converter through the virtual internal potential control parameters and the equivalent circuit; s3, calculating a constraint condition II of control parameters of the model in different operation states according to a constraint condition I of grid-connected operation of the converter; s4, performing parameter scanning on the value range of the control parameters based on a constraint condition II, and generating a solution space meeting the constraint condition II; and S5, according to the functional characteristics of the converter, obtaining the optimal parameter combination of the virtual internal potential control parameters in the solution space. The method further optimizes the virtual internal potential control algorithm, improves the adaptability and safety of the virtual internal potential control algorithm under various power grid fault conditions, and improves the stability and reliability of a new energy grid-connected system.

A resonant converter switching between different operational state modes is provided. The resonant converter includes a first transistor, a second transistor, a control circuit, a resonant circuit, a transformer and an output stage circuit. A first terminal of the first transistor and a second terminal of the second transistor are connected to positive and negative terminals of an input voltage source, respectively. A first terminal of the second transistor is connected to a second terminal of the first transistor. The resonant circuit is connected to the second terminal of the first transistor and the transformer. The transformer is connected to a load through the output stage circuit. The control circuit modulates frequencies or duty cycles of conduction time control signals that are outputted to the first and second transistors to different values for switching the resonant converter between the operational state modes.

The embodiment of the invention discloses a band-gap reference circuit, a reference voltage source and a reference voltage generation method, and the circuit comprises a current module, a differential input module, a limiting module, a feedback module and a voltage division module, the differential input module responds to a first voltage signal and a second voltage signal of the voltage division module to generate a first conduction current and a second conduction current respectively, and then outputs a first output current and a second output current respectively; and the limiting module responds to the first output current and the second output current, and outputs a driving signal to control the feedback module to adjust the first voltage signal and the second voltage signal, so that the first output current is equal to the second output current, and the differential input module outputs the reference voltage with the zero temperature coefficient. The limiting module comprises a matching resistor or a low-transconductance switch tube so as to reduce the offset voltage. The matching resistor or the low-transconductance switch tube is arranged in the limiting module, so that the offset voltage of the limiting module is reduced, and the accuracy of the reference voltage is improved.

The invention relates to an arrangement for supplying electrical energy to a direct liquid cooling (DLC) system, wherein the arrangement comprises at least one IT rack (1) with a plurality of vertically arranged (z) slots (2) for plug-in devices (2.1) of a direct liquid cooling (DLC) system and / or an IT infrastructure, characterized in that the IT rack (1) has a DC power supply (3) for plug-in devices (2.1) received in the slots (2), with a rectifier (PSU) and a busbar (5) which runs along a rear side (R) of the IT rack (1) in the vertical direction (z) of the IT rack (1) and is supplied with a DC voltage by the rectifier (PSU), wherein at least one plug-in device (2.1) of a direct liquid cooling (DLC) system is received in one of the slots (2) and is electrically contacted with the busbar (5).

The invention discloses a source network load storage coordination control system and method for high-capacity multi-network energy storage combined transportation. The system comprises a master station layer which is responsible for receiving a superior scheduling instruction, issuing an emergency control instruction, and performing economic optimization scheduling and rapid coordination control on photovoltaic and energy storage resources; the substation layer is responsible for accessing photovoltaic, load and energy storage resource information and decomposing and issuing superior instructions to realize a local frequency voltage control function; and the terminal layer is used for receiving a generator tripping command or a power regulation command issued by the emergency state monitoring device. The system can effectively improve the network-related performance of a new energy station, enhance the stability and reliability of a power grid, improve the absorption capability of new energy, and optimize the economical efficiency of the system. Through combined operation of the network construction type energy storage equipment and the new energy, effective support for the power grid is realized, the problem of coordination control of parallel operation of multiple voltage sources is solved, oscillation and circulation are avoided, and the overall performance and the power supply guarantee capability of the system are improved.

The invention provides a transient current capability improvement control system and method of a wind and light power generation system. The system comprises a self-synchronizing voltage source control module, a junction temperature prediction module, a transient current improvement control module, a current instruction calculation module and a transient current precise control module. According to the invention, online observation of the junction temperature of the wind-solar converter power device can be realized, the maximum short-circuit current which can be output can be accurately predicted, the DC bus voltage, the switching frequency and the modulation strategy are adjusted when the power grid has a fault, the junction temperature of the power device is reduced, and the transient current endurance capability of the power device is improved. And the transient current is accurately controlled to limit the utilization of the transient capability of the power device.

A device for extracting CO2 from air comprises at least one extraction reactor (12) through which CO2-containing air (L) flows in an adsorption operation, having an adsorption surface; a heating arrangement (40) for heating the at least one extraction reactor (12) at least in the region of its adsorption surface to a temperature above an extraction gas desorption temperature in a heating / desorption operation; and at least one extraction gas storage (48) for storing CO2 desorbed from the at least one extraction reactor (12) in the heating / desorption operation. The extraction reactor (12) comprises at least one substrate with a plurality of flowable cells or flow channels of a porous structure, wherein the adsorption surface is formed on the substrate, and wherein the at least one substrate is electrically conductive and can be heated by applying an electrical voltage.wherein the heating arrangement (40) comprises the at least one substrate and a voltage source (42) for applying an electrical voltage to the at least one substrate.

A power converter system includes a DC voltage source, a control system, a multilevel inverter and a balancing circuit connected to the DC voltage source, and at least two DC link series connected capacitors connected between a positive and a negative voltage supply line (V+, V−) of the DC voltage source and having a mid-point therebetween. The balancing circuit comprises a plurality of switches that are connected in series between said positive and a negative voltage supply line (V+, V−), the plurality of switches arranged in a first pair of switches and a second pair of switches. A flying capacitor is connected between a mid point of the first pair of switches and a mid point of the second pair of switches, and an inductor is connected between said DC link capacitor mid point and a mid point between the first pair of switches and second pair of switches.

In certain aspects, a voltage regulator includes a pass transistor coupled between an input of the voltage regulator and an output of the voltage regulator, and an amplifier having a first input coupled to a reference voltage, a second input coupled to the output of the voltage regulator via a feedback path, and an output. The voltage regulator also includes a voltage booster coupled between the output of the amplifier and a gate of the pass transistor. In certain aspects, the voltage booster includes a first capacitor and a second capacitor for double charge pumping. In certain aspects, a control circuit of the voltage booster is coupled to a voltage source that is independent of an output voltage of the amplifier.

The invention discloses an SOC prediction method and system for a lithium ion battery of an electric forklift. The method comprises the steps that real-time data in the discharging process of the lithium ion battery are acquired; analyzing a real-time data change rule, and constructing a characteristic parameter model; a second-order RC equivalent circuit model is constructed, the model comprises a voltage source, an ohmic resistor and a second-order RC network, and the second-order RC network is used for describing the polarization effect of the charging and discharging stage; obtaining parameter identification results of the dynamic driving working conditions at different temperatures based on an ant colony algorithm; memory historical feature extraction of the time series data is realized based on a TCN model, including expansion convolution, causal convolution and residual connection; and selecting an average absolute percentage error and a mean square error as evaluation indexes. According to the method, parameter identification results of dynamic driving working conditions at different temperatures are obtained through the ant colony algorithm, the parameter identification results are input into the TCN model through corresponding transformation, and finally SOC estimation with high precision and robustness is achieved in LiFePO4.

The invention discloses a bidirectional self-adaptive inertia control method and device for an interconnected converter, and the method comprises a voltage source converter structure, a bidirectional inertia control method and self-adaptive inertia coefficient set.The bidirectional self-adaptive inertia control method and device are suitable for an AC-DC hybrid micro-grid so as to balance AC micro-grid frequency and DC micro-grid voltage dynamic response. Virtual synchronous motor control is adopted as a control outer ring to realize power adjustment and emergency control mode switching, an additional virtual capacitor control ring is designed to suppress the influence of high-frequency interference on a differential element, and the method can enable an IC to adjust a working mode to operate in a rectification or inversion state under a self-adaptive operation condition, so that the reliability of the IC is improved. The strategy enables the interconnection converter to smoothly adapt to three operation modes of grid connection, island power adjustment and island emergency control, thereby balancing the dynamic response characteristics of the two modes after disturbance, and achieving the improvement of the overall performance of the AC / DC micro-grid.

The invention relates to a pre-charge device (3041, Shu, 110, 120, 130, 140, µC) for a load, for example a capacitor (Ca), from a DC voltage source (102) comprising a first safety transistor (3041) capable of connecting the load (Ca) to said DC voltage source (102), and a control circuit (Shu, 110, 120, 130, 140, µC) in linear mode of the first safety transistor (3041), characterized in that said control circuit (Shu, 110, 120, 130, 140, µC) regulates the product of the pre-charge current (Ipr) and the voltage difference between the voltage measured across said DC voltage source (102) and the voltage measured across said load (Ca) with respect to a power setpoint (CP). during the linear control of the first safety transistor (3041) during the pre-charging of said load (Ca) by said DC voltage source (102),said power setpoint (CP) increasing during a first time interval from a first predefined value, for example zero, to reach a constant or approximately constant value and remain there for a second time interval following the first time interval. Figure for the abbreviation: Fig. 4,

The invention discloses a voltage source type energy storage and new energy collaborative active grid-connected operation method and system, and belongs to the technical field of grid connection. The method comprises the steps that new energy grid-connected node parameters are acquired, and a voltage source type energy storage power station / new energy hybrid power system Thevenin equivalent circuit is constructed; according to a Thevenin equivalent circuit of the voltage source type energy storage power station / new energy hybrid power system, static stability limits of output power of different new energy power stations are calculated; based on the static stability limit, constructing a relationship between virtual impedance and reactive output of the energy storage system when new energy output approaches the static limit; based on the relation between virtual impedance and reactive power output of an energy storage system, for a new energy power station with low static operation margin, virtual impedance parameters and reactive power output values of a matched voltage source type energy storage power station are changed, so that the stability limit of new energy grid-connected operation is improved. The method not only can improve the stability and adaptability of the system, but also can optimize the economical efficiency of the system and promote the wide application of new energy.

The present disclosure provides a control method and control apparatus for a voltage source-type wind turbine. The control method comprises: performing a proportional-integral-derivative operation on a deviation between a DC bus voltage measurement value and DC bus voltage reference value of a wind turbine to obtain an active power deviation; determining a virtual angular frequency deviation on the basis of the active power deviation; determining a virtual internal potential phase on the basis of the virtual angular frequency deviation; obtaining a d-axis virtual impedance output and an q-axis virtual impedance output by means of inputting a grid-connected current in a dq coordinate system to a virtual impedance module; on the basis of the virtual angular frequency deviation, a reactive power setting value and reactive power measurement value of the wind turbine, a rated voltage amplitude of a grid, the d-axis virtual impedance output and the q-axis virtual impedance output, determining a d-axis component and q-axis component of a modulation voltage; and controlling an injection voltage of a grid-connected point of the wind turbine according to the virtual internal potential phase and the d-axis component and q-axis component of the modulation voltage.

The low-power fast wake-up band-gap reference voltage circuit operates in three phases: dormant, wake-up, and steady-state phases. The circuit enters wake-up subsequent to receipt of an enable signal which causes a one-shot timer to generate a slew enable signal pulse having a predetermined period. To a band-gap voltage reference circuitry comprising an operational amplifier, there is connected, at the wake-up phase, a boost circuitry, operative under the control of the slew enable signal that connects one or more of the one or more boost circuits to a band-gap voltage reference. Thereby, during the brief wake-up phase, more current is consumed to accelerate the response of the circuit. Upon completion of the wake-up phase the boost circuitry is disconnected under the control of the slew enable signal and for as long as the enable signal is active, the circuit is operative in a low-power mode.

The invention provides a fault ride-through control method for a network construction type converter, and belongs to the technical field of energy storage converters and the like. The method comprises the following steps: firstly, measuring PCC voltage and power grid side current, calculating amplitudes of the PCC voltage and the power grid side current, and then judging whether the PCC voltage drops below a set threshold value or not; if not, keeping the active power reference and the voltage amplitude reference unchanged; and if so, performing active power reference modification: judging whether a current limiting strategy is triggered, if not, locking the PCC voltage reference as a measured value, and if so, gradually decreasing the PCC voltage reference by an increment value based on the measured value. According to the invention, accurate evaluation of the existence of the stable equilibrium point is realized; meanwhile, an improved fault ride-through control method is provided, active power reference and voltage amplitude reference are dynamically modified, so that the grid-forming converter is transited to a new stable balance point during a fault period, and current limiting, transient synchronization stability improvement, PCC voltage source characteristic maintenance and maximum fault current output can be taken into account.

The invention provides a current limiting method and device based on active compensation, electronic equipment and a converter, and relates to the technical field of network construction. The current limiting method based on active compensation comprises the following steps: acquiring a current actual current value and a maximum allowable current value of a grid-connected converter; determining a current difference value between the maximum allowable current value and the current actual current value; determining the compensation amount of the angular frequency according to the current difference value; the compensation amount of the angular frequency is in negative correlation with the current difference value; compensating an angular frequency reference value of the grid-connected converter according to the compensation amount of the angular frequency to obtain a compensated angular frequency reference value; and performing network construction type control on the grid-connected converter according to the compensated angular frequency reference value. The purpose of current limiting can be achieved, the current limiting response speed is high through current limiting, the grid-connected converter still keeps the characteristics of a voltage source, the maximum power capacity output of the converter can be maintained, the maximum power grid supporting capacity of the converter is guaranteed, and the stability of a power grid is improved.

A disclosed switching apparatus, such as a circuit breaker, includes a transistor switch circuit connected between a power input terminal and a load terminal, and, connected to the power input terminal and bypassing the transistor switch circuit, a switchable bypass leg that is optically switched by a series-connected photoconductive semiconductor switch (PCSS). The transistor switch circuit includes at least one cascade of three or more series-connected transistors, and at least one resistor network configured to divide a voltage from a voltage source across a cascade of series-connected transistors. Operating the switch apparatus includes detecting whether a sensed electric current is in a fault condition, opening the transistor switch circuit upon detecting a fault condition, and then closing the PCSS so that the electric current is diverted onto a switchable bypass path. The opening of the transistor switch circuit comprises turning OFF a normally-ON transistor switch circuit.