1279 results about "Secondary side" patented technology

The invention discloses a low-harmonic high-voltage speed regulation system based on a multi-pulse phase-shifting transformer, and particularly relates to the field of power electronic technology and motor speed regulation, which is characterized in that the primary side of the multi-pulse phase-shifting transformer is in star connection, and N groups of windings on the secondary side are in extended delta connection, so that phase difference is realized; the multi-path low-voltage alternating current is converted into multi-path low-voltage alternating current and low-order harmonics are High voltage is output through cascade H-bridge topology series connection, and reliable conversion is guaranteed through rectification filtering inversion and device redundancy design; the motor control module collects signals through multiple sensors, and PWM drive signals are generated through a vector control algorithm and coordinate transformation. The harmonic detection and compensation module detects harmonic waves based on an FFT algorithm, and injects a reverse compensation component through a modulation strategy to offset the harmonic waves; and the auxiliary protection module integrally realizes low-harmonic and high-precision high-voltage motor speed regulation through multi-dimensional monitoring and hardware protection.

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 discloses a multi-machine common-bus generator system stator grounding fault active arc extinction method based on online calculation of ground capacitance parameters, and the method comprises the following steps: S1, connecting a controllable current source in parallel with a secondary side of a generator neutral point grounding transformer, and injecting current into a neutral point; extracting a voltage component with the same frequency as the injection current, and calculating a ground capacitance parameter of the generator system on line through the voltage component and the injection current value; s2, measuring the three-phase phase voltage of the generator and the phase value of the zero-sequence current at the generator end of the generator, and solving the fundamental wave potential of a fault point based on the measured value; deriving a compensation current needing to be injected at the generator end side of the fault phase generator, and injecting the compensation current at the generator end; and S3, after compensating current is injected into the generator ends to realize arc extinguishing of fault points, measuring the generator end zero-sequence current phase of each generator again, and performing fault selective positioning, thereby determining a fault unit in the multi-generator common-mother system. According to the method, effective arc extinction can be realized, and the fault unit can be reliably judged.

The invention discloses a half-bridge ZVS Buck-Boost converter and a control method thereof, and belongs to the technical field of power converters, the half-bridge ZVS Buck-Boost converter comprises a primary side conversion module, a voltage transformation module and a secondary side conversion module, and the primary side conversion module, the voltage transformation module and the secondary side conversion module are connected in sequence; the primary side conversion module comprises a first bridge arm, a second bridge arm, a first inductor and a bidirectional switch, the first bridge arm and the second bridge arm are connected in parallel, a bridge arm midpoint of the first bridge arm is connected with a first end of the first inductor, a second end of the first inductor is connected with a first end of the voltage transformation module, and a second end of the voltage transformation module is connected with a second end of the voltage transformation module. The second end of the voltage transformation module is connected with the bridge arm midpoint of the second bridge arm, the bridge arm midpoint of the first bridge arm is connected with the first end of the bidirectional switch, and the second end of the bidirectional switch is connected with the bridge arm midpoint of the second bridge arm. According to the invention, zero-voltage switching-on of the half-bridge circuit switching tube in a full-input, full-output and full-load range under a constant switching frequency can be realized.

The invention provides a liquid cooling system cooling capacity distribution unit control method, device and unit and a liquid cooling system. The method comprises the steps that current hydraulic parameters of cooling liquid in a secondary side liquid supply and return pipeline are obtained; if the current hydraulic parameter is smaller than a preset hydraulic threshold value and the absolute difference value between the current hydraulic parameter and the preset hydraulic threshold value is larger than a first preset difference value, the frequency of a circulating pump and / or the opening degree of a bypass valve are / is adjusted according to the current hydraulic parameter and the preset hydraulic threshold value so as to increase the flow of cooling liquid in a secondary side liquid supply and return pipeline; and if the current hydraulic parameter is larger than a preset hydraulic threshold value and the absolute difference value is larger than a first preset difference value, the frequency of a circulating pump and / or the opening degree of a bypass valve are / is adjusted according to the current hydraulic parameter and the preset hydraulic threshold value so as to reduce the flow of the cooling liquid in the secondary side liquid supply and return pipeline. Heat dissipation control can be carried out timely and accurately, the heat dissipation performance of the liquid cooling system is improved, the heat dissipation requirement of the server is met, and normal operation of the server is guaranteed.

The utility model provides a transformer module which comprises a primary side assembly, a secondary side assembly and a magnetic element. The primary side assembly is provided with a first cover body, a first column body and a first coil. The first column body is connected to the first cover body. The first coil is wound on the first cylinder. The secondary side assembly is provided with a second cover body, a second column body and a second coil. The second column body is connected to the second cover body. The second coil is wound on the second cylinder. The magnetic element is arranged between the primary side assembly and the secondary side assembly. The first column body is fixedly connected to the second column body, and the size of the first column body is larger than that of the second column body.

The invention relates to the technical field of power system monitoring, discloses an anti-harmonic PT current monitoring system and method, and aims to solve the problem of secondary side current signal distortion of a voltage transformer caused by power grid harmonic pollution in the prior art. The method comprises the steps of electrifying and initializing a system, starting a high-speed analog-to-digital converter to acquire a voltage signal, executing fast Fourier transform to identify dominant harmonic waves, calculating and configuring a capacitance value of a tunable LC trap unit to suppress specific harmonic waves, and finally outputting a high-fidelity analog voltage signal in direct proportion to fundamental current. The system comprises a current-voltage conversion module, a tunable LC notch filter array, a high-speed analog-to-digital converter, a digital signal processing unit and a microcontroller. According to the technical scheme, dynamic self-adaptive suppression and precise selective harmonic wave blocking of power grid harmonic waves can be realized, low delay and high fidelity characteristics are guaranteed, and the engineering practicability and reliability of the system are improved.

The invention discloses a PT ferromagnetic resonance adaptive collaborative suppression method and system, and the method comprises the steps: sampling a voltage signal, a current signal and a PT secondary side voltage signal monitored by a high-voltage end sensing unit in real time, and calculating a primary side voltage change rate and harmonic content; comparing the calculated primary side voltage change rate and harmonic content with corresponding preset thresholds, controlling to input a neutral point reconstruction unit, and destroying resonance conditions by changing neutral point grounding impedance; after the neutral point reconstruction unit works, the input energy feedback unit is controlled and used for absorbing resonance energy; and when it is detected that the resonance threat is eliminated, the neutral point reconstruction unit and the energy feedback unit are controlled to be turned off in sequence, and active cooling of the high-voltage end sensing unit is started by using residual energy in the energy feedback unit. According to the method, by monitoring the voltage change rate and the harmonic content in real time, a neutral point is rapidly triggered to reconstruct and damage resonance, energy is absorbed and fed back through an energy feedback unit, and finally system safety recovery is achieved.

The invention discloses a current transformer based on decoupling compensation and an adjusting method thereof, and relates to the technical field of current measurement. The method comprises the following steps: establishing an error coupling matrix by data acquired by a current transformer; a decoupling compensation hardware module is designed, and decoupling compensation is carried out on the exciting current, the secondary load and the transient component; establishing a working condition parameter set, and constructing a training sample library by taking the working condition parameters as input and the compensation coefficients as output based on a BP neural network; through a clock synchronization module, it is ensured that output signals of the three compensation units and current signals of the secondary side of the mutual inductor are the same in frequency and phase; different working conditions are simulated through the standard current source, and the adjusted precision is recorded. According to the invention, through multi-dimensional error decoupling and combination of the BP neural network and the PID, hardware shunting and algorithm optimization are utilized to realize separated compensation of three errors, the method is adaptive to complex working conditions, and the adjustment precision of the compensation circuit is improved.

A three-phase wireless electric energy transmission device disclosed by the present invention comprises a three-phase inverter, a three-phase switch capacitor, a coil magnetic field coupling structure and a rectifier, the coil magnetic field coupling structure comprises a primary coil and a secondary coil which are arranged in mirror symmetry, the primary coil is provided with two layers, each layer comprises a three-phase coil, each phase coil occupies a 120-degree angle range of the circumference, and the rectifier is connected with the primary coil and the secondary coil. The two layers of coils form a staggered angle, each phase of switched capacitor of the three-phase switched capacitor comprises a first capacitor branch and a second capacitor branch which are arranged in parallel, the first capacitor branch is provided with a first capacitor, and the second capacitor branch comprises a second capacitor and a switch module which are arranged in series; the switch module adjusts the equivalent capacitance value of the second capacitor branch through the duty ratio and adjusts the transmission power of the three-phase wireless power transmission device. The invention further discloses a load power adjusting method of the three-phase wireless power transmission device, the transmission efficiency can be kept unchanged within the adjusting range, and soft switching can be achieved within the adjusting range.

The application discloses a single-stage three-phase high-frequency isolation type conversion circuit and a closed-loop control method. The single-stage three-phase high-frequency isolation type conversion circuit generates a modulation ratio and a vector angle on the basis of synchronous control of a fundamental wave and a harmonic wave of a three-phase current based on three-phase voltage of a three-phase three-wire power grid and the three-phase current of the three-phase three-wire power grid, generates a primary side driving signal and a secondary side driving signal according to the modulation ratio and the vector angle, the primary side driving signal is used for driving a three-phase matrix converter, and the secondary side driving signal is used for driving a full-bridge inverter. The fundamental wave and the low-frequency harmonic wave of the power grid current can be synchronously controlled, low-order harmonics can be eliminated, the sinusoidal degree of the grid-connected current can be improved, and thus the quality of the power grid current and total harmonic distortion can be improved.

The invention relates to the technical field of electric energy metering error compensation, in particular to an electric energy metering error compensation method, device and system, and the method comprises the steps: collecting a single-phase electric energy signal of a secondary side of a power grid transformer, and uniformly dividing the single-phase electric energy signal into each section of metering signal sequence; calculating high-frequency unsteady-state energy to quantify distortion by extracting first-order and second-order quasi-steady-state components of a metering signal sequence; meanwhile, impact pulses in the dynamic components are recognized, impact characteristics are analyzed through clustering, and the nonlinear impact disturbance degree is comprehensively calculated; the fundamental wave separation strength of each section of metering signal sequence is calculated, the initial step length factor of the LMS filtering algorithm is dynamically adjusted, effective separation of fundamental waves and distortion signals is achieved, and therefore electric energy metering error compensation is completed. The method aims at solving the problem that the metering precision of a traditional fixed step length factor is reduced under the power grid nonlinear load high permeability working condition, and the accuracy and reliability of electric energy metering are ensured.

The invention relates to the technical field of electric variable data compensation, in particular to a metering error dynamic compensation method and system of an intelligent measuring switch. The method comprises the following steps: calculating to obtain phase delay compensation time of each sampling point based on original instantaneous current of each sampling point, equivalent excitation inductance of a current transformer, internal resistance of a secondary side winding, resistance value of a sampling resistor and a magnetic circuit saturation critical current value; performing high-order correction on the original instantaneous current to obtain a real current value of the sampling point; based on the original instantaneous voltage, the real current value and the phase delay compensation time of the sampling point in the metering period, the active power of the metering period is calculated so as to realize metering error dynamic compensation, and the accuracy of active power calculation of the intelligent measurement switch in the dynamic load switching process can be effectively improved.

The invention discloses a capacitor voltage transformer on-line verification and state early warning method and system, and the method comprises the steps: synchronously collecting the secondary side time sequence data of a target CVT and other CVTs of the same bus with the target CVT through a power monitoring system; based on secondary side time sequence data of a plurality of CVTs on the same bus, screening out a CVT equipment group with consistent state through group consistency analysis, and generating a virtual standard reference value for error calculation; calculating a relative deviation between the secondary voltage measurement value of the target CVT and the virtual standard reference value as a first evaluation result; performing feature extraction on the secondary side time sequence data to obtain a feature vector representing the operation state of the target CVT, inputting the feature vector into a pre-trained intelligent evaluation model to obtain an error prediction value or a health state score of the target CVT, and taking the error prediction value or the health state score as a second evaluation result; and fusing the first evaluation result and the second evaluation result to obtain a comprehensive evaluation conclusion of the running state of the target CVT, and if the state level exceeds a normal range, generating early warning information.

The invention discloses a control system and method for industrial circulating water heat exchange equipment, and the method comprises the following steps: collecting the data of a regulating valve and a sensor in real time; comprise the opening value of a regulating valve located on the primary side, the first temperature of a primary side water return pipe, the second temperature of a primary side water supply pipe, the first pressure value and the second pressure value before and after the regulating valve of the primary side water return pipe, the third temperature of the secondary side water supply pipe and the fourth temperature of the secondary side water return pipe; the instantaneous flow of the primary side is calculated according to the collected data of the regulating valve and the sensor; and based on the instantaneous flow of the primary side, collecting data of the regulating valve and the sensor, and calculating to obtain a real-time dirt coefficient under the current working condition. The method has the beneficial effects that the dirt coefficient is calculated online in real time and serves as a core basis for control decision making, and the system can intelligently switch control targets under different health states of the heat exchanger.

The invention provides a current transformer saturation detection method and system, and relates to the technical field of state detection and fault diagnosis of current transformers, and the method comprises the steps: synchronously collecting the secondary side current, bus voltage, cable insulation and partial discharge data of a current transformer, and carrying out the normalization according to classes, and then completing the time sequence alignment; secondly, a fixed sliding window is set, current distortion rate, voltage over-limit frequency, insulation parameter mean value and partial discharge pulse quantity characteristics are extracted, and whether current transformer saturation, insulation abnormity and partial discharge abnormity events exist in the window or not is judged according to the current distortion rate, the voltage over-limit frequency, the insulation parameter mean value and the partial discharge pulse quantity characteristics; counting the saturation probability under each node state based on a Bayesian causal network, calculating and normalizing the causal contribution degree of the insulation abnormity and the partial discharge abnormity to the saturation event, and determining a dominant influence factor; and finally, a health index is calculated in combination with the normalized contribution degree and the abnormal state, the running health condition of the current transformer is evaluated through trend analysis in combination with a dominant factor, saturation inducements are positioned, and misjudgment is avoided.

A system includes: an alternating current (AC) to direct current (DC) converter (AC-DC converter), the AC-DC converter connectable to a line voltage; and a DC to DC converter (DC-DC converter) connected to the AC-DC converter, the DC-DC converter including: a high voltage buck-boost converter having a secondary side connectable to a high voltage battery; a low voltage buck-boost converter having a secondary side connectable to a low voltage battery; and one or more transformers having a primary side connected to the AC-DC converter, a secondary side connected to a primary side of the high voltage buck-boost converter, and a tertiary side connected to a primary side of the low voltage buck-boost converter.

A battery pack charger having housing including a battery pack interface for removably receiving a battery pack and a power input. The battery pack charger including a hybrid flyback converter having a primary side including a DC-DC half-bridge and a secondary side including a synchronous rectifier. The hybrid flyback converter is electrically connected between the power input and the battery pack interface and is configured to provide charging power from the power input to the battery pack interface.

The invention discloses a medium-voltage voltage regulating circuit, system and method, and belongs to the technical field of medium-voltage power distribution. The medium-voltage voltage regulating circuit comprises a tapped voltage regulating transformer Tr1, a voltage compensation unit, a current compensation unit and a direct-current supporting unit, the self-coupling winding of the Tr1 and the series transformer of the voltage compensation unit are connected in series to a medium-voltage main circuit, the parallel winding of the current compensation unit and the self-coupling winding of the Tr1 share a magnetic core and take the self-coupling winding of the Tr1 as a primary side and a secondary side, and the direct current sides of the power module of the voltage compensation unit and the power module of the current compensation unit are both connected to the direct current supporting unit. Wide-range voltage coarse adjustment is achieved through the Tr1, stepless voltage fine adjustment is achieved through the voltage compensation unit, meanwhile, the topological structure is simplified through the common magnetic core coupling design of the self-coupling winding and the parallel winding of the Tr1, the equipment size, the magnetic loss and the manufacturing cost are reduced, and the stability and reliability of a medium-voltage power distribution system are remarkably improved.

A resonant converter includes an input circuit, a first switch circuit, a resonant circuit, a voltage regulation circuit, a second switch circuit, and an output circuit. The first switch circuit is coupled to the input circuit and includes first switch units. The resonant circuit includes resonant tanks, each resonant tank includes a resonant capacitor and a resonant inductor which are coupled in series, and the resonant inductors are coupled to the output nodes of the first switch units by wye connection. The resonant capacitors are coupled to the primary side of the voltage regulation circuit by the wye connection. The second switch circuit includes second switch units and is coupled to the second switch circuit, and the input nodes of the second switch units are coupled to the secondary side of the voltage regulation circuit by delta connection. By the aforementioned arrangement, ZVS or ZCS is implemented.

A power supply includes a converter circuit, a switching circuit and a control circuit. The converter circuit includes a transformer, a primary side switch and a secondary side switch. The switching circuit includes first and second capacitors, first and second sets of switches. In a first phase, the primary side switch is in the conduction state, causing a magnetizing inductor of the transformer to store energy. In a second phase, the primary side switch is in the off state, causing the magnetizing inductor to release the energy. In a first mode of the second phase, a first amount of the energy is transferred through the first set of switches to the first capacitor. In a second mode of the second phase, a second amount of energy is transferred to the second capacitor through the second set of switches.

The present disclosure relates to a kind of direct current transformer, direct current transformer includes: transformer circuit, inverter circuit, rectifier circuit and resonance circuit;The direct current side of inverter circuit is connected with direct current input port, the alternating current side of inverter circuit is connected with the primary side of transformer circuit;The alternating current side of rectifier circuit is connected with the secondary side of transformer circuit, the direct current side of rectifier circuit is connected with direct current output port;Resonance circuit includes multiple resonance modules, the alternating current side of inverter circuit is connected with the alternating current side of rectifier circuit through multiple resonance modules and transformer circuit;Resonance module includes first capacitor, resonance module is used to control the input or cut-out of first capacitor.The present disclosure can simulate the voltage outputted when direct current transformer adopts different capacitance resonant capacitor, so as to ensure that direct current transformer does not need to set resonant capacitor, can satisfy the realization condition of resonant soft switching in different working condition scene, and then make the switching device in inverter circuit and rectifier circuit can realize soft switching.

This application belongs to the field of nuclear power plant engineering, specifically relating to a device for secondary side maintenance of a horizontal steam generator used in a nuclear power plant. The device includes: an air supply duct, an air supply fan, an exhaust duct, and an exhaust fan. One end of the air supply duct enters the steam generator through a manhole and extends to the bottom of the heat transfer tubes of the steam generator; the other end of the air supply duct is connected and fixed to the outlet of the air supply fan. One end of the exhaust duct is placed on an underwater steam distribution plate inside the steam generator, and the other end passes through the manhole and is connected and fixed to the inlet of the exhaust fan. No special placement platform is required; any location on site can be used as a placement location. Internal maintenance can be achieved simply by opening one manhole, improving maintenance efficiency.

A switching power supply and an electronic device includes a transformer, which includes a frame and a multi-layer winding structure arranged on the frame, different winding units are distributed at intervals along a target direction; at least one winding unit includes a first winding of the primary side of the transformer; at least one winding unit includes a second winding of the secondary side of the transformer; at least one winding unit includes a shielding winding; at least one group of shielding windings and the first winding are wound in parallel in the same layer, and / or: at least one group of shielding windings are distributed between the first winding and the second winding; the shielding winding is located on the primary side of the transformer; at least one end of the shielding winding is connected to an oscillation reduction unit for eliminating or weakening oscillation.

The invention discloses an output voltage compensation method, device and assembly of a dual-active bridge converter. The method comprises the steps of obtaining a first voltage and a first current of a grid-side power supply and a second voltage and a capacitance value of an integration module; according to the zero crossing point moment of the first voltage, an insertion beat compensation starting point of the output voltage of the energy storage output module is determined; the insertion beat compensation starting point is a target moment after the zero crossing point moment; according to the first voltage and the first current of the network side power supply, the second voltage and the capacitance value of the integration module and the switching period of the switching module of the secondary side bridge arm circuit, the voltage compensation amount of an insertion beat compensation end point is determined; according to the voltage compensation amount of the integration module at the end point of the beat insertion compensation, determining beat insertion time; and controlling the conduction state of the secondary side bridge arm circuit at the insertion time at the insertion compensation starting point so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero crossing point moment of the first voltage. According to the technical scheme provided by the embodiment of the invention, the oscillation of the output voltage is improved.

The application discloses a kind of magnetic coupling isolation type IGBT driving systems, comprising: primary low-voltage side module, for connecting external microcontroller;Secondary side high-voltage side module, for connecting functional semiconductor device, secondary side high-voltage side module is connected with primary low-voltage side module by isolation band module communication, the secondary side high-voltage side module includes adjustable power supply unit, anti-interference unit, adaptive drive unit and collaborative protection unit, the adjustable power supply unit includes the power input end of anti-interference unit, adaptive drive unit, collaborative protection unit is connected respectively, the independent reverse fault feedback channel of " collaborative protection unit to isolation band module again to primary low-voltage side module " is constructed in the application, for the differentiated transmission and identification of different types of fault signals Special hardware foundation is provided, the limitation that only single high-low level fault signal can be transmitted in prior art is completely broken, so that primary microcontroller can obtain enough information to distinguish specific fault type.

A secondary side controller for an AC-DC converter, the secondary side controller having a single synchronous rectifier sense (SR_SNS) terminal coupled to a synchronous rectifier (SR) of the AC-DC converter, and a voltage divider circuit coupled to the single SR_SNS terminal, the voltage divider circuit configured to provide a signal to a sense circuit. The voltage divider includes an active diode, an internal resistive element, and a switch, wherein the active diode is configured to control the switch to enable or disable the internal resistive element based on a comparison of a voltage at the single SR_SNS terminal to a reference voltage.

A voltage control module of the power supply circuit is used for transmitting an induced voltage to a constant voltage output module when the induced voltage is less than a preset stabilized voltage, and is switched on and stops outputting the induced voltage when the induced voltage is greater than the preset stabilized voltage. The constant voltage output module discharges to output a preset constant voltage; the induced voltage is obtained according to the induced current of the secondary side of the current transformer; the current sampling module is used for sampling induced current to obtain an amplified voltage signal; the control module is used for obtaining the actual current of the primary side of the current transformer according to the amplified voltage signal, and generating a control signal when the actual current is greater than a preset current threshold value; the switch protection module is used for responding to the control signal and switching between connection and disconnection so as to share energy of the voltage control module during connection. The power supply circuit is high in stability, energy is shared through conduction of the switch protection module in heavy load, and safety and reliability of the circuit are improved.

A power conversion circuit, includes the following elements. A transformer, includes a primary side winding, a first secondary side winding and a second secondary side winding. A first switching circuit, connected to the primary side winding. A second switching circuit, connected to the first secondary side winding. A third switching circuit, connected to the second secondary side winding. A first output capacitor, connected to the second switching circuit and the first secondary side winding, and has a first voltage value. The second output capacitor, connected to the third switching circuit and the second secondary side winding, and has a second voltage value. A control circuit, controls the first switching circuit, the second switching circuit and the third switching circuit to be turned-on or turned-off according to the first voltage value and the second voltage value, so as to charge the first output capacitor or the second output capacitor.

The invention discloses a bidirectional DC-AC converter control method considering a soft switching condition and current optimization. According to the invention, the switching loss of the converter is reduced by optimizing the phase shift angle and the switching condition of the converter, and the energy transmission efficiency is optimized by minimizing the effective value of the current, so that the performance of the whole sodium battery energy storage system is improved. Specifically, based on the relation between the excitation inductance Lm and the current effective value Iprms, the phase shift angle of the converter is accurately controlled, the current transmission efficiency is optimized, and it is ensured that the zero-voltage switching condition of a primary side bridge arm and a secondary side bridge arm can be achieved in the working process, so that the loss of the converter is remarkably reduced, and the energy conversion efficiency is improved.