3618 results about "AC power" patented technology

The invention provides a network following type and network constructing type energy storage combined planning method and device, and belongs to the field of power system planning. The method comprises the following steps: in a to-be-planned grid following type energy storage and grid construction type energy storage power system, carrying out joint modeling on a grid following type converter, a grid construction type converter and a fed alternating current power grid, so as to obtain a closed loop transfer function of the power system; based on the closed-loop transfer function, constructing a small-interference stability security domain oriented to energy storage joint planning; and converting the small-interference stability security domain into a small-interference stability security constraint, and further establishing a multi-type energy storage joint planning model to obtain a joint planning scheme of following network type energy storage and constructing network type energy storage. According to the method, the influence of the operation condition of the converter on small interference stability can be considered, power system optimization targets such as new energy consumption and the like are considered, and combined optimization configuration of network following type and network construction type energy storage is realized.

The invention provides a tumor electric field treatment system, an electrode slice temperature detection method and an electrode slice anomaly detection method, the system comprises an alternating current signal generator, an electrode slice and a controller, the electrode slice comprises a plurality of electrode units and a plurality of temperature detection units, the plurality of temperature detection units are divided into a plurality of row groups and a plurality of column groups, and the plurality of electrode units are connected with the controller. The grounding ends of the temperature detection units in each row group are jointly connected to the same grounding wire, and the signal ends of the temperature detection units in each column group are connected to the same dual-purpose signal wire after being in short circuit with the corresponding electrode units; when the dual-purpose signal line is connected to the temperature sampling point, the grounding wires are sequentially conducted, so that temperature detection signals detected by the temperature detection units are sampled based on the temperature sampling point; when the dual-purpose signal line is connected to the alternating power line, alternating electric signals are transmitted to the electrode units. Therefore, the temperature of the electrode plate can be detected by using fewer conductive traces, and whether the electrode plate is abnormal or not can be judged through temperature detection.

An energy storage system comprises a set of swappable battery modules positioned in battery slots with a battery module being controlled by a control switch. The control switches are linkable to form a charging control chain and / or a discharging control chain respectively to control sequential charging / discharging, parallel charging / discharging, and segmented charging / discharging among the set of battery modules in the energy storage system. Methods to detect defective battery module in a battery slot are also presented. The energy storage system can be configured in an AC power distribution environment, a DC power distribution environment, or in an EV. The energy storage system is scalable, automatically reconfigurable and accepts AC power and regenerated DC power.

The invention relates to the technical field of unit power failure detection, in particular to an AC power supply input power failure detection method and system. The AC power supply input power failure detection method comprises the following steps: comparing a characteristic voltage value with a preset threshold value; triggering a sampling frequency adjustment mechanism according to the preliminary detection signal, increasing the sampling rate according to the voltage fluctuation frequency by adopting an adaptive algorithm, and obtaining high-precision sampling data through real-time calculation; for the optimized power consumption control scheme, acquiring current system state data, coordinating quick response capability and low power consumption optimization through a state machine algorithm, and outputting a multi-stage interaction strategy signal; adjusting a dynamic threshold value of capacitance voltage division design according to the multi-stage interaction strategy signal, and predicting voltage fluctuation by adopting a Kalman filtering algorithm to obtain smoothed detection sensitivity data; and analyzing the misjudgment rate reduction degree through a threshold fine tuning algorithm in combination with the abnormal fluctuation characteristics and the partial pressure state, and outputting a final power failure detection result.

The invention discloses an output voltage detection method and system based on an aviation power supply, and relates to the technical field of aviation power supply voltage detection. A differential voltage sensor is connected to the output end of an aviation power supply, a high-frequency suppression capacitor is connected in parallel, the sampling rate of 20-50 times of the working frequency is set according to the type of the power supply, and the signals are collected and converted into analog voltage signals; the analog signal is subjected to two-stage filtering, is amplified to 0-5V through an instrument amplifier, and is converted into a digital voltage sequence through a 16-bit ADC (Analog to Digital Converter); calculating AC power supply effective value, peak value and other parameters, DC power supply average value, ripple coefficient and other parameters; comparing the characteristic parameters with a preset threshold value, determining that the characteristic parameters exceed the threshold value and recording related information; and a detection result is transmitted to a monitoring terminal through an RS485, data is locally stored, and a switching value is output to an alarm device when the data is abnormal. The method adapts to aviation power supply load fluctuation and environment temperature change, detection precision is high, data transmission and storage are safe, abnormity is accurately identified and early warning is carried out in advance, and aviation power supply operation and maintenance reliability and efficiency are improved.

The invention provides a power system economic dispatching method considering dynamic capacity increase of a line and a related device. The method comprises the following steps: establishing a target function taking the minimum unit operation cost of a power system as a target; determining constraint conditions of the target function according to the parameters of the power system, wherein the constraint conditions comprise unit constraint, network variable constraint, linearized alternating current power flow constraint and linearized line thermal stability constraint; the economic dispatching model of the power system is solved, an economic dispatching scheme of the power system is obtained, and the economic dispatching model of the power system comprises a target function and constraint conditions. According to the method, the temperature change of the line is tracked by using the linearized line thermal stability constraint, so that the transmission capacity of the line can be improved on the basis of meeting the thermal stability constraint, an economic dispatching strategy is optimized, and the economic dispatching efficiency is improved by linearizing the alternating current power flow constraint and the line thermal stability constraint. The power system economic dispatching model is constructed into a mixed integer linear programming model, so that the solving speed and efficiency of the model can be improved.

A multiple input converter for outputting power from AC power or a battery to positive and negative direct current (DC) buses is provided. The multiple input converter includes at least one bridge arm unit and a bidirectional DC-DC conversion unit. The bridge arm unit corresponds to one phase of the alternating current (AC) power and includes an upper and lower bridge arms that can independently form a two-level converter. In a battery mode, the upper and lower bridge arms discharge power from the rechargeable battery to the positive and negative DC buses, and the bidirectional DC-DC conversion unit discharges power from the rechargeable battery to the positive and negative DC buses or balances voltages of the positive and negative DC buses. In a mains mode, the bridge arm units are connected to the AC power. The bidirectional DC-DC conversion unit determine whether to charge or discharge according to load conditions.

A wireless power transfer (WPT) device includes a polyphase coil network comprising a plurality of phases for transfer of high-frequency AC power, each one of the plurality of phases comprising a phase coil, wherein the polyphase coil network is configured to operate in a polyphase configuration to enable transfer of polyphase high-frequency AC power with a mating WPT device operating in a polyphase mode; and operate in a single phase interoperability configuration to enable transfer of single phase high-frequency AC power with a mating WPT device operating in a single phase mode.

The invention relates to an AC-DC integrated grounding fault positioning method and system, and the method comprises the steps: collecting the potential change data of a DC power supply system and the frequency characteristic data of an AC power supply system, and determining the electrical signal characteristics of stray current corrosion; decomposing the electric signal by using wavelet transform, and extracting direct-current and alternating-current components; determining a fault type according to the component amplitude; analyzing the potential gradient and the stray current flow direction in combination with a line topological structure, and determining the position of a fault point; measuring resistance to determine a grounding loop, and analyzing the correlation between corrosion distribution and electrical parameter characteristics; evaluating the influence of corrosion on the grounding path in combination with the material resistivity; according to the method, faults can be accurately recognized, fault points can be accurately positioned, the corrosion degree and the influence of the corrosion degree on the system can be evaluated, and effective support is provided for safe operation and maintenance of a subway power supply system.

The invention relates to the field of power grid simulation, and particularly discloses a control method of an alternating-current power grid broadband oscillation simulation device based on a component physical model, which realizes broadband domain oscillation simulation of an alternating-current power grid based on the component physical model and a notch filter. Specifically, according to the control method of the alternating-current power grid broadband oscillation simulation device based on the element physical model, an adjustable element physical model type and a corresponding impedance parameter serve as input conditions, and a dynamic voltage compensation component excited by power grid impedance is calculated in combination with an adjustable notch filter; and a power grid simulation reference signal is constructed in real time through superposition of an original input reference voltage value and a dynamic voltage compensation component excited by power grid impedance, so that oscillation simulation in a wide frequency domain of the alternating-current power grid is realized.

The invention discloses a fault processing method for an offshore wind power direct current parallel sending-out system through a DRU-MMC. The fault processing method comprises the steps that direct current energy consumption devices are arranged at direct current outlets of respective land MMC converter stations of a DRU-HVDC system and an MMC-HVDC system; when the alternating current power grid at the receiving end has an alternating current fault, the direct current energy consumption device is controlled to adopt a direct current voltage suppression strategy; when the DRU-HVDC system and the MMC-HVDC system respectively have direct current faults, different locking and circuit breaker disconnection time sequence control strategies are adopted, and in the direct current fault ride-through period, a direct current suppression strategy and a direct current voltage suppression strategy are controlled to be adopted by a direct current energy consumption device of the DRU-HVDC system. Therefore, the fault ride-through capability of the DRU-MMC direct current parallel sending-out system of the offshore wind power can be effectively improved, and stable operation of the system is ensured.

The invention relates to the technical field of power systems, and discloses a new energy grid-connected system broadband oscillation risk assessment method, system, device and medium, and the method comprises the steps: constructing an impedance external characteristic model of a new energy station, and constructing impedance external characteristic models of an AC power grid of different broadband oscillation risk assessment frequency bands; therefore, different broadband oscillation risk assessment frequency bands are flexibly processed, and the impedance external characteristic model of the new energy station and the impedance external characteristic model of the AC power grid are used to determine the impedance external characteristic curve of the new energy station and the impedance external characteristic curve of the AC power grid. And performing broadband oscillation risk assessment on the new energy grid-connected system by using a comparison result of the impedance external characteristic curve of the new energy station and the impedance external characteristic curve of the alternating current power grid, and fully considering the influence of a topological structure and an operation condition on the broadband oscillation risk. And the broadband oscillation risk assessment accuracy and adaptability of the new energy grid-connected system are improved.

The invention discloses a novel photovoltaic optimizer based on PLC communication, which comprises a hardware module, a control module, a communication module and a service module, and is characterized in that the hardware module is used for constructing a system material basis and realizing electric energy calling, signal coupling and equipment protection, and the control module is used for realizing intelligent power regulation and communication control; the power generation efficiency is improved and the communication stability is guaranteed through a multi-modal algorithm, and the communication module is used for constructing a power line carrier communication system. A special PLC framework for a direct-current low-voltage environment is adopted, a communication frequency band and an impedance matching scheme can be designed according to photovoltaic direct-current side characteristics, technical field differentiation is formed from alternating-current power grid PLC patents, through dual-mode MPPT dynamic switching, the limitation of a single algorithm in a dynamic environment can be broken through through combination of local gradient prediction and a distributed collaborative algorithm, and the real-time performance of a photovoltaic power grid is improved. In cooperation with a passive impedance compensation technology, adaptive adjustment can be performed through the magnetic ring filter and the capacitor array, an additional power supply module is not needed, and the hardware complexity is reduced.

An emergency LED lighting system maintains power to an LED lighting source based on measured voltages and currents provided to the LED lighting source; rolls back or decreases power provided to an LED lighting source over time in order to increase the amount of time the battery can power the LED lighting source; executes a soft start procedure, such that the power provided to the LED lighting source is gradually ramped up during activation of the LED lighting sources; identifies a type of battery coupled to the emergency LED lighting system; cycles the emergency LED lighting system between charging mode and standby mode to reduce power consumption over a window of time; detects AC power or an absence of AC power; and / or uses a status LED to communicate information about the emergency LED lighting system with a remote device.

The invention, which relates to the technical field of direct-current power transmission, discloses a co-offshore medium-high-frequency alternating-current offshore wind power full-direct-current collection system comprising: an offshore wind turbine module, which is used for obtaining offshore medium-voltage direct-current electric energy; the multi-port direct-current voltage transformation module is used for converting the offshore medium-voltage direct-current electric energy into offshore high-voltage direct-current electric energy; the direct-current submarine cable module is used for gathering the offshore high-voltage direct-current electric energy, acquiring the gathered offshore high-voltage direct-current electric energy and transmitting the gathered offshore high-voltage direct-current electric energy to the shore converter station module; the shore converter station module is used for acquiring shore high-voltage alternating-current electric energy according to the collected offshore high-voltage direct-current electric energy; the onshore alternating current module is used for receiving the onshore high-voltage alternating current electric energy and achieving full-direct-current collection of offshore wind power. By improving the medium voltage-high voltage direct current transformer topological structure and the control method, efficient and economical electric energy transmission is realized, the construction economy and the engineering application value of an open-sea wind power collection system are improved, and the average price and low price requirements of marketization development are met.

The motor control device that controls driving of a motor connected to a power converter performing power conversion from DC power to AC power, the motor driven using the AC power, includes a carrier wave generation unit that generates a carrier wave, a carrier wave frequency adjustment unit that adjusts the frequency of the carrier wave, and a gate signal generation unit that generates a gate signal for controlling operation of the power converter by performing pulse width modulation of a voltage command corresponding to a torque command using the carrier wave, and the carrier wave frequency adjustment unit adjusts the frequency of the carrier wave in accordance with the torque command and the rotation speed of the motor so that a phase of pulsating torque due to command current generated by the pulse width modulation using the carrier wave overlaps a phase of pulsating torque due to interlinkage magnetic flux of the motor within a predetermined phase difference.

The invention provides a current source type hybrid direct-current power transmission system based on an injection type power grid commutation converter, and relates to the field of high-voltage direct-current power transmission, and the system comprises a rectification station which at least comprises a thyristor-based power grid commutation converter and is used for converting alternating current into direct current; the inverter station at least comprises an injection type power grid commutation converter and is used for converting the direct current output by the rectifier station into alternating current; and the control module is used for controlling the operation of the rectifier station and the inverter station based on the trigger time sequence constraint, and has the advantages of completely inhibiting the commutation failure and reducing the loss.

A power converter (100) for converting multi-phase AC grid input power (GIV, GIC) to DC output power. For allowing efficient, cost-effective, easy installable, and reliable power supply to a DC power consumer with high power requirements, it includes at least one phase block (106A, 106B), each having at least two separate converter single-phase string arrangements (1), each of them including an individual active rectifier portion (10), including a H-bridge with semiconductor switches (12), for rectifying single-phase AC input power (SInV, SInC) to intermediate DC power and an individual DC / DC converter (20). The latter includes an inverter portion (30), having a H-bridge with semiconductor switches (32), for inverting the intermediate DC power to first intermediate AC power (PAC1) with an elevated frequency (f1), a transformer (40, 240) for transforming the first intermediate AC power (PAC1) to second intermediate AC power (PAC2, PAC2A, PAC2B), and a passive diode rectifier (50, 150, 250), including a diode bridge (51), for rectifying the second intermediate AC power (PAC2, PAC2A, PAC2B). The disclosure further discloses a hydrogen production facility (200) with an electrolyzer stack (20) and such a power converter (100).

The invention discloses a deep and far sea wind power direct current delivery system based on a flexible thyristor converter and a control method. The deep and far sea wind power direct current delivery system based on the flexible thyristor converter comprises a plurality of offshore wind power direct current delivery systems, a direct current large bus, an onshore converter station and an onshore alternating current power grid. The offshore wind power direct current sending-out system is composed of a wind power plant, a collection network, an offshore converter station and a direct current submarine cable which are connected in sequence. The land converter station is composed of an alternating current line, a land converter and a direct current line which are connected in sequence. The invention discloses a deep and far sea wind power direct current delivery system topological structure and a control method, which can realize concentrated collection and high-capacity delivery of receiving ends of a plurality of long-distance offshore wind fields, deeply utilize complementarity of power fluctuations of the plurality of offshore wind fields, improve construction economy of a deep and far sea wind power grid-connected delivery system and annual utilization hours of a direct current delivery channel, and reduce the construction cost of the deep and far sea wind power grid-connected delivery system. And the flexibility and expansibility of the grid-connected system are effectively enhanced.

The invention discloses a three-phase uninterruptible power supply device and a control method thereof. The control method comprises the following steps: acquiring an input current of a three-phase alternating current power supply and a load voltage and a load current of an output end of an inverter circuit; carrying out harmonic separation on the collected input current, and determining a total harmonic distortion rate; when the total harmonic distortion rate is greater than a preset total harmonic distortion rate threshold value, generating a harmonic compensation signal; calculating load variation and voltage deviation based on load voltage and load current, dynamically adjusting proportional gain and integral time in real time, and generating a fundamental voltage control signal; superposing the fundamental wave voltage control signal and the harmonic compensation signal to generate a preliminary modulation wave; dynamically adjusting the dead zone time of the PWM wave, and combining the dead zone time with the preliminary modulation wave to generate the PWM wave; according to the control method, the three-phase alternating current is converted into the alternating current meeting the load requirement through the PWM waves, the response capacity to voltage sag, voltage fluctuation and harmonic disturbance is improved, and the output electric energy quality is improved.

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.

An onboard charging system for an electric vehicle includes a charging port configured to receive a single-phase AC power, a power outlet configured to provide the single-phase AC power to one or more external devices, a single-phase inverter connected to the power outlet and configured to provide power splitting functionality, a DC battery selectively coupled to the charging port, a bidirectional inverter configured to convert AC power to DC power and to convert DC power to AC power, the bidirectional inverter is selectively coupled to the battery, an electric motor coupled to the bidirectional inverter and selectively coupled to the charging port, a DC-AC converter selectively coupled to the electric motor and selectively coupled to the power outlet, and a DC-DC converter coupled to the DC-AC converter and selectively coupled to the battery.

The invention provides a totem pole PFC circuit control method and a power conversion device. The totem-pole PFC circuit comprises a first inductor, a first bridge arm and a second bridge arm, the first bridge arm and the second bridge arm are connected in parallel between the positive electrode and the negative electrode of the DC interface of the totem-pole PFC circuit, the first end of the first inductor is connected to the midpoint of the first bridge arm, and the second end of the first inductor and the midpoint of the second bridge arm are used for being connected with an AC power supply. The method comprises the following steps: controlling switch tubes of a first bridge arm and a second bridge arm to be closed within a first duration starting from a first moment before each zero-crossing moment of an alternating current power supply, and controlling a main switch tube of the first bridge arm to work within a second duration starting from a second moment after the zero-crossing moment, the follow current switch tubes of the second bridge arm and the first bridge arm are controlled to be closed; wherein the last moment of the first duration is the second moment. According to the control method provided by the invention, the leakage current of the power conversion device comprising the totem-pole PFC circuit can be effectively reduced.

A single-stage AC-to-DC resonant converter is used to convert a three-phase AC power source into a DC power source. The single-stage AC-to-DC resonant converter includes a primary-side circuit, a resonant circuit, and a secondary-side circuit. The primary-side circuit includes three primary-side switch circuits, and each primary-side switch circuit is coupled to one phase of the three-phase AC power source. The resonant circuit includes three transformers, and primary-side windings of the transformers are respectively coupled to the primary-side switch circuits, and secondary-side windings of the transformers are coupled to the secondary-side circuit.

The invention relates to the technical field of power system optimization dispatching, in particular to a frequency constraint unit commitment optimization method, device and equipment based on linear alternating current power flow and a medium. According to the method, second-order cone convex relaxation processing is conducted on a non-convex alternating current power flow equation, and a unit commitment model is constructed; frequency safety constraints are introduced into the unit commitment model, the frequency safety constraints comprise frequency safety margin constraints and system equivalent inertia constraints, and a frequency constraint unit commitment model is formed; a two-stage progressive optimization strategy is adopted for solving the frequency constraint unit combination model, in the first stage, the unit start-stop state and an initial power generation plan are determined through the unit combination model, in the second stage, the multi-period alternating current optimal power flow model is solved in the fixed start-stop state to correct the result, and a final power generation plan is obtained; according to the method, the solving efficiency and the frequency safety are both considered, and the safety and economy of power grid operation are remarkably improved.

The invention discloses a moving-coil direct-drive gravity energy storage device and a control method thereof, and belongs to the technical field of gravity energy storage. The moving-coil direct-drive gravity energy storage device comprises a direct-drive conveying system, an energy storage unit and an upper computer; the direct-drive conveying system comprises an alternating-current power grid, an energy storage converter, a direct-drive motor unit and a plurality of primary rotor carriers, one end of the energy storage converter is electrically connected with the alternating-current power grid, and the other end of the energy storage converter is electrically connected with the direct-drive motor unit through a direct-current bus. According to the device, electric energy and potential energy are efficiently and bidirectionally converted through the direct-drive conveying system and the energy storage unit, simultaneous movement of the multiple rotors is achieved, and the space efficiency ratio of gravity energy storage is increased; and compared with a traditional energy storage mode, redundant movement intermediate mechanisms are removed, unnecessary parts and connection are reduced, the installation space is effectively saved, the maintenance difficulty and cost are reduced, and the energy storage device can be applied to wider field conditions.

The invention discloses a DC-output offshore wind and light new energy collection system and a control method thereof, which are applied to the technical field of power grids, and the system comprises a DC bus, a DC-DC converter, a DC line, an inverter, an offshore converter station, an AC power grid, a plurality of DC transmission units and a plurality of new energy power generation units. The output end of each new energy power generation unit is connected in series with each direct current transmission unit; the direct current transmission units transmit electric energy to the direct current-direct current converter through the direct current bus, and the direct current bus is connected with the direct current transmission units in parallel; the output end of the DC-DC converter transmits electric energy to the receiving end of the inverter through the DC line; the inverter transmits electric energy to the alternating current power grid through the offshore converter station. According to the system and the method provided by the embodiment of the invention, the power of the power grid can be controlled, and the stability of the system is ensured.

A power supply switching system includes a switch controlling apparatus, at least two switch apparatuses, alternating current (AC) powers, and a power shelf. The power shelf includes at least two AC inputting ends. Each of the at least two switch apparatuses is electrically connected between one of the AC inputting ends and the AC powers. A number of the AC powers is less than a number of the at least two AC inputting ends. The switch controlling apparatus is electrically connected with each of the at least two switch apparatuses, and controls the at least two switch apparatuses to turn on or turn off. The power supply switching system saves a number of the AC powers while executing an ATS test, thus an efficiency of the power shelf is improved. A switch apparatus is also provided.

A series-type hybrid circuit breaker to provide protection against short circuit faults in DC or AC power circuits. A series-type hybrid circuit breaker (SHCB) forces a fault current into a high-frequency AC current with zero crossings and allows a mechanical circuit breaker to disconnect the faulty branch. The SHCB injects a transient counter voltage pulse via a pulse transformer into the main power loop upon detection of an overcurrent condition and forces the fault current to change its original direction and cross zero to a negative peak value. A generation power electronic circuit on the primary side of the transformer controls the discharge of a capacitor to generate the counter voltage pulse during the first phase of each switching cycle of the fault interruption process. The power electronic circuit then changes the polarity of the injected secondary voltage and forces the fault current to change direction and cross zero again.

An electric power conversion apparatus includes an inverter configured to convert input DC power into AC power, and a control device configured to control the inverter, wherein the control device is configured to prioritize limiting one of an active current and a reactive current output from the inverter over the other of the active current and the reactive current, so that an apparent current output from the inverter becomes less than or equal to a limit value.