3393 results about "Secondary side" patented technology

A system includes: an AC-DC converter; and a DC-DC converter, the DC-DC converter including: a first high voltage buck-boost converter having a secondary side connectable to a first high voltage battery; a second high voltage buck-boost converter having a secondary side connectable to a second high voltage battery; a first low voltage buck-boost converter having a secondary side connectable to a first low voltage battery; a second low voltage buck-boost converter having a secondary side connectable to a second low voltage battery; and one or more transformers having a primary side connected to the AC-DC converter and a secondary side connected to each of a primary side of the first high voltage buck-boost converter, a primary side of the second high voltage buck-boost converter, a primary side of the first low voltage buck-boost converter, and a primary side of the second low voltage buck-boost converter.

The invention provides a mutual inductor fault diagnosis method based on multi-sensor data fusion and transfer learning, and the method comprises the following steps: S1, installing a plurality of high-precision sensors on the secondary side of a voltage transformer to be subjected to fault diagnosis based on the voltage transformer to be subjected to fault diagnosis; s2, on the basis of the step S1, performing data acquisition and processing on data acquired by various high-precision sensors through a DHDAS dynamic signal acquisition instrument; and S3, based on the step S2, carrying out fault diagnosis on the voltage transformer through a PC (Personal Computer) carrying acquisition analysis software on the DHDAS dynamic signal acquisition instrument. According to the method, multi-mode signals such as voltage, current and temperature are synchronously collected, time-frequency domain features are extracted through continuous wavelet transform, the dynamic characteristics of interlayer short circuit faults can be more comprehensively represented, meanwhile, by combining transfer learning and a deep neural network, the intelligent diagnosis model can remarkably improve the classification performance under the condition that sample data is small, and the classification efficiency is improved. And the limitation of a single-mode signal diagnosis method is effectively overcome.

A multi-phase LLC resonant converter circuit (10) includes: first to third LLC resonant converters each including a series circuit (S1 to S3) of a first switch and a second switch that are connected in parallel to a DC power supply, a high-frequency transformer (T1 to T3) including a primary-side winding and a secondary-side winding, a resonant circuit including a resonant reactor (Lr1 to Lr3) connected between a connection point of the first switch and the second switch and one end of the primary-side winding, a resonant capacitor (Cr1 to Cr3) in which one end is connected to the other end of the primary-side winding, and a divided resonant capacitor (Cn1 to Cn3) in which one end is connected to a connection point of the primary-side winding and the resonant capacitor; a first neutral line (N1) that connects the other end of the resonant capacitor; a neutral line reactor (Ln) connected between the first neutral line and a power supply line of the DC power supply; and a second neutral line (N2) that connects the other end of the divided resonant capacitor.

An automotive power system includes an AC / DC power converter, a transformer, a switching bridge connected between the AC / DC power converter and transformer, and a switch bank connected with a secondary side of the transformer. The switch bank connects the secondary side between an electric machine and another switching bridge such that the electric machine, first switching bridge, transformer, and second switching bridge form an isolated DC / DC power converter. The system further includes one or more switches configured to directly connect the traction battery between the AC / DC power converter and second switching bridge.

The invention discloses a zero-sequence pilot-frequency excitation method for a double-circuit line in an incomplete power failure environment, which comprises the following steps of: applying zero-sequence pilot-frequency signal excitation on a power failure line by using a pilot-frequency power supply as an excitation signal source of a zero-sequence network of the double-circuit line, different-frequency induced current and voltage are measured at secondary sides of a current transformer and a voltage transformer at two sides of the operation line, and different-frequency zero-sequence voltage and different-frequency zero-sequence current in the double-circuit line zero-sequence network are obtained; simultaneously solving a zero-sequence network equation, and calculating mutual impedance between double circuits; performing frequency conversion to obtain the power frequency mutual impedance of the line; and finally, carrying out simulation verification by constructing a non-full-stop double-circuit line zero-sequence mutual inductance impedance measurement system. According to the method, the multi-path coupling caused by the existing power frequency interference method and the accuracy problem caused by the signal measurement error of the zero sequence increment method are solved, the test calculation can be accurately completed under the complex interference working condition, and the safety risk caused by the single-phase reclosing operation is avoided.

The invention provides a circulation power optimization method and system for a three-phase dual-active bridge, and relates to the field of power electronics, the method comprises the following steps: determining an optimal backflow modulation strategy set corresponding to a hybrid modulation group, the hybrid modulation group comprising triangular wave modulation, trapezoidal modulation, synchronous modulation and extended phase shift modulation, the optimal backflow modulation strategy set corresponding to the hybrid modulation group comprises modulation modes and degree-of-freedom relationships corresponding to different transmission power per unit value ranges in different voltage conversion ratio ranges; determining a degree of freedom and power relationship set corresponding to the hybrid modulation group, wherein the relationship set comprises a relationship between the degree of freedom and power of different transmission power per unit values corresponding to each mode; the phase shift angle, the primary side duty ratio and the secondary side duty ratio are determined by combining the real-time voltage conversion ratio and the real-time virtual power per unit value, operation of the three-phase dual-active bridge is controlled, and the method has the advantages of reducing complexity and improving portability and efficiency.

The invention discloses an anti-direct-current component nanocrystalline current transformer and a using method thereof. The anti-direct-current component nanocrystalline current transformer comprises a current transformer body, and a magnetic core hole penetrating front and back is formed in the middle of the front side of the current transformer body. The device is provided with a secondary side open circuit detection and protection mechanism, so that imbalance of a magnetic field in the mutual inductor caused by disconnection of a secondary loop is effectively prevented, iron core magnetic flux saturation and potential high electromotive force generation are avoided, the safety of the mutual inductor and peripheral equipment is protected, the risk of power system faults such as fire disasters or short circuits is reduced, and meanwhile, the safety of the mutual inductor is improved. A live wire centering fixing mechanism is arranged, so that the stable centering position of a wire in a magnetic core hole of the mutual inductor is ensured, magnetic field distribution is optimized, the magnetic leakage phenomenon is reduced, the accuracy and stability of current measurement are remarkably improved, meanwhile, measurement fluctuation caused by wire shaking is reduced, and the measurement precision is improved. And more accurate data support is provided for harmonic analysis, fault detection and electric energy quality monitoring of a power system.

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.

The invention relates to a medium-voltage expansion ice melting device and an ice melting expansion system. The medium-voltage expansion ice melting device comprises an ice melting transformer and a reactive compensation unit, the primary side of the ice-melting transformer is electrically connected with the power supply end of the medium-voltage power supply, and the secondary side of the ice-melting transformer and the input end of the reactive compensation unit are electrically connected with the ice-melting output end; wherein the ice melting transformer is a double-winding ice melting transformer of which the primary side is subjected to on-load voltage regulation and the secondary side is subjected to no-load gear regulation, and the medium-voltage power supply comprises a medium-voltage emergency power supply vehicle or a power grid; the deicing transformer is used for adjusting the alternating current of the medium-voltage power supply into the adjustable alternating current of the line section to be deiced, and the reactive compensation unit is used for regulating and controlling the reactive compensation current and the reactive compensation power. According to the technical scheme of the invention, the medium-voltage emergency generator car can be fully utilized to quickly expand the ice melting function of the medium-voltage emergency generator car, and meanwhile, the ice melting technical equipment of power grid power supply can be considered, and the economy of distribution network ice melting is improved.

The present disclosure provides a signal delay setting circuit, an isolation integrated circuit and a power conversion circuitry. The isolation integrated circuit includes a primary side circuit, an isolation circuit and a secondary side circuit. The primary side circuit generates a primary side signal according to a first input signal and a second input signal. The isolation circuit converts the primary side signal into a secondary side signal. The secondary side circuit receives the secondary side signal through the isolation circuit, to generate an output signal. The signal delay setting circuit is coupled to the secondary side circuit, calculates a delay time according to a voltage difference between an alternative terminal and a secondary side ground terminal of the isolation integrated circuit, and delays the secondary side signal according to the delay time, to control the duty ratio of the output signal.

The invention relates to the technical field of equipment control, in particular to a self-adaptive switching method and system of a current transformer. The method comprises the following steps: collecting primary side parameters and secondary side parameters of a current transformer to obtain primary side collection parameters of the current transformer and secondary side collection parameters of the current transformer; performing current transformer state segmentation initialization according to the current transformer primary side acquisition parameters and the current transformer secondary side acquisition parameters so as to generate a current transformer operation state classification result; switching result judgment is conducted on the current transformers according to the current transformer operation state classification result, and when the current transformer operation state classification result is a current transformer critical state section, parallel buffering is conducted on the current transformers, and critical current transformer switching data are generated. According to the invention, through accurate state classification, a dynamic switching mechanism, time sequence optimization and visual display, the switching sensitivity and stability of the current transformer are improved.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The invention discloses a fault diagnosis method and system for a metering error of a voltage transformer, and relates to the technical field of power equipment fault diagnosis, and the method comprises the steps: obtaining the historical electric quantity data of a secondary side under the normal operation of the voltage transformer, and carrying out the noise reduction and normalization preprocessing; establishing an initial principal component analysis model according to the preprocessed historical electric quantity data, and calculating to obtain a statistic control threshold value; updating a mean vector and a covariance matrix of the model by adopting a dynamic strategy based on real-time acquired new electric quantity data of the secondary side of the voltage transformer; and calculating a new statistic according to the updated mean vector and the covariance matrix, comparing the new statistic with a statistic control threshold value, and if the new statistic is greater than the statistic control threshold value, determining a metering error fault. According to the invention, the model parameters can be updated according to the real-time change data output by the voltage transformer, the adaptability to different metering error ranges of the voltage transformer is improved, and the detection precision is improved.

The present application provides a converter and a chopper transistor blocking control method therefor. According to the chopper transistor blocking control method, when switching transistors in a converter need to be blocked, switching transistors in a primary side circuit connected to a transformer of the converter are blocked, and switching transistors in a secondary side circuit are blocked when the current on a branch where a secondary side winding in the transformer is located is zero, or batch blocking of the switching transistors in the secondary side circuit is completed after the current on the branch where the secondary side winding is located recirculates to zero, thereby avoiding overvoltage damage to the switching transistors caused by the current on the branch where the secondary side winding is located recirculating by means of the junction capacitance of the switching transistors in the secondary side circuit.

The invention discloses a CLLLC converter light load efficiency improvement and load expansion circuit based on variable resonant cavity regulation and control and a control method thereof. The circuit comprises a primary side full bridge, a variable resonant cavity, a secondary side rectifier and an output loop, the digital control unit detects the load in real time, and drives and switches the parallel or series capacitor branch to adjust the equivalent resonant capacitor; and the auxiliary buffer branch is used for soft start and sudden change buffer. According to the control method, capacitance is reduced during light load, efficiency is improved, capacitance is increased during heavy load, gain linearity is kept, the load range is widened, and smooth starting is achieved. The device is compact in structure and easy to control, the light load efficiency can be remarkably improved, the load application range is expanded, and the device has high reliability and good industrialization prospects.

The disclosure provides a method for improving the efficiency of a micro-inverter, and a dual-active-bridge-type micro-inverter. The method including: performing power modulation mode switching of a dual-active-bridge-type micro-inverter, such that the power is bi-directionally transmitted from a direct-current side to an alternating-current side and from the alternating-current side to the direct-current side, thereby reducing an effective value of a secondary side current of a transformer; and according to the modulation mode switching characteristic of the dual-active-bridge-type micro-inverter within a power frequency period, performing hybrid optimization on the turn ratio of a primary side to a secondary side and a transformer leakage inductance of a high-frequency transformer of the dual-active-bridge-type micro-inverter.

The invention belongs to the technical field of mutual inductor verification, and particularly relates to a data processing method for testing a current mutual inductor, so as to solve the technical problem that an existing verification method cannot truly reflect the comprehensive error of the mutual inductor, and the method comprises the following steps: S1, obtaining the current waveform data of a tested current mutual inductor; s2, deducting the exponential decay aperiodic component from the original current waveform data to obtain corrected current waveform data; s3, reconstructing to obtain de-noised current waveform data; s4, acquiring fundamental waves of the primary side current and the secondary side current and setting amplitude and phase angles of subharmonics; s5, calculating an initial ratio error and an initial angle error of the current transformer; s6, generating a ratio error compensation vector and an angular difference compensation vector; and S7, respectively carrying out vector summation on the initial ratio error and the initial angle error with the ratio error compensation vector and the angle error compensation vector to obtain the final ratio error and the final angle error of the current transformer. And the test accuracy and reliability of the ratio difference and the angle difference of the current transformer are improved.

The invention discloses a general transient DC bias suppression method for a dual-active-bridge converter under bidirectional power flow. The method comprises the following steps: when the dual-active-bridge DC converter operates stably, asynchronous carriers are generated; a certain modulation and control strategy is adopted, closed-loop operation is carried out in each switching period, and a primary side inner shift phase ratio D1, a secondary side inner shift phase ratio D2 and an outer shift phase ratio Df are generated; different working modes are selected according to the positive and negative relation of the external shift comparison between the current switching period and the previous switching period, and an asynchronously updated modulation wave is generated; and according to the selected working mode, determining a lead and lag relationship of the modulation wave, comparing the modulation wave with the carrier wave, and generating a driving signal of a power switch of the dual-active bridge converter. According to the method, the problem that an existing transient direct current bias suppression method is only suitable for a specific power flow direction or a specific modulation strategy can be solved, transient direct current bias suppression under power bidirectional flow is achieved, and safe operation of the dual active bridge converter is guaranteed.

A multi-phase resonant power converter includes: a power stage on a primary side of the multi-phase resonant power converter, the power stage including bridge converter legs each configured to receive an AC input voltage and implement a separate phase of the power converter; a transformer device having a primary side winding for each bridge converter leg and a secondary side winding for each primary side winding; a power circuit electrically connected to the secondary side windings on a secondary side of the multi-phase resonant power converter; a primary-side controller configured to operate the bridge converter legs at a switching frequency; and a separate resonant tank electrically connected to a midpoint of each bridge converter leg. Each resonant tank includes a resonant capacitor in series with the primary side winding for that bridge converter leg. A resonant frequency of each resonant tank is tuned to within + / −50% of the switching frequency.

A power converter includes a transformer, a resonant circuit, a first switch and a second switch, a resonant adjustment circuit, and a controller. The transformer includes a primary-side winding and a secondary-side winding coupled to the primary-side winding. The resonant circuit is coupled to the primary-side winding, and the resonant circuit includes a resonant capacitor and a resonant inductor provided by at least the primary-side winding. The first switch and the second switch are commonly connected to a node, and the node is coupled to the resonant circuit. The resonant adjustment circuit is coupled to the resonant circuit. The controller is used to control an enabled time of the resonant adjustment circuit according to an output voltage of the power converter so as to maintain the efficiency of transmitting the energy from the primary-side winding to the secondary-side winding under a full output voltage range.

The invention provides a fault-tolerant control method and a fault-tolerant control system for a dual-active bridge series resonant converter (DBSRC), and aims to solve the problems that the voltage and current stress is increased, the system reliability is reduced and the like caused by an open-circuit fault of a primary side switch tube or a secondary side switch tube. Through the dynamic reconstruction modulation strategy and the same bridge arm driving follow current suppression method, under the condition that redundant hardware is not needed, the voltage and current stress in the fault state is effectively reduced, and stable operation of the system is maintained. The method specifically comprises the following steps: when a primary side open-circuit fault occurs, optimizing a control parameter by adopting extended phase shift modulation (EPS), and compensating for loss of a power transmission path; and when the secondary side has an open-circuit fault, the driving signal of the other switching tube of the same bridge arm is cut off, and the direct-current bias of the resonance current is eliminated. According to the method, the fault-tolerant capability of the DBSRC is remarkably improved, the hardware cost and the maintenance complexity are reduced, and the method is suitable for a high-frequency isolation direct-current conversion system.

The invention discloses an open-circuit fault diagnosis method for a switching tube of a dual-active bridge converter. The open-circuit fault diagnosis method comprises the following specific steps: modeling the dual-active bridge converter; analyzing voltage and inductance waveform characteristics of the dual-active bridge converter in a fault state of each switching tube on the primary side and the secondary side; comparing and analyzing fault features of each switching tube, and selecting a difference value between an inductive current average value and a bridge arm midpoint voltage average value in a fault state and a normal state as a fault feature; and designing a fault diagnosis algorithm according to the selected fault features. Compared with a traditional fault diagnosis method, only the voltage of one bridge arm of the primary side and the voltage of one bridge arm of the secondary side are selected as fault features, fewer sensors are needed, and real-time online fault diagnosis is more accurate and rapid.

An isolated bi-directional DC conversion circuit and a method for controlling the same are provided. The DC conversion circuit includes a transformer with a first energy storage element and a primary-side rectification bridge coupled to the primary side of the transformer and a second energy storage element and a secondary-side rectification bridge coupled to the secondary side of the transformer. The primary-side rectification bridge consists of multiple first power switching devices. The secondary-side rectification bridge consists of multiple second power switching devices. Each of the multiple first and the second power switching devices have a body diode in inverse parallel connection therewith. The DC conversion circuit further includes multiple first sampling resistors provided on each bridge arm of the secondary-side rectification bridge and a controller configured to perform switch control on the multiple second power switching devices based on a sampled voltage of the multiple first sampling resistors.

The invention discloses an online monitoring method for abnormal operation of a voltage transformer, and the method comprises the steps: firstly collecting the secondary side voltage data of a CVT in real time, forming a time sequence, building a bilateral sliding window with a to-be-measured point as a center, and sliding along a time axis to cover a complete sequence; then, K-Means clustering initialization is executed on each sliding window, the clustering number K is set to be equal to 2, two initial centroids are randomly selected, and the distance between each piece of voltage data and the two centroids is calculated; thirdly, dividing the voltage value in the window into the closest centroid category, and recalculating a new centroid until the position of the centroid is stable or reaches the maximum number of iterations; and finally, calculating a current window clustering centroid distance in real time, comparing the current window clustering centroid distance with a dynamic threshold value obtained by historical data training, and judging whether the CVT has an internal fault or not. The method utilizes the existing voltage data, does not need an additional measuring instrument, can adapt to different operation conditions, avoids the over-alarm problem of a traditional fixed threshold value method, and improves the accuracy and robustness of fault diagnosis.

A system includes: an alternating current (AC) to direct current (DC) converter (AC-DC converter) including a bulk capacitor, the AC-DC converter connectable to a line voltage; a DC to DC converter (DC-DC converter) connected to the AC-DC converter, the DC-DC converter including: one or more transformers having a secondary side connectable to a battery, and a bridge rectifier connected to the secondary side of the one or more transformers, the bridge rectifier including a bridge rectifier switch; and one or more controllers configured to control an operation of the bridge rectifier switch to control a voltage of the bulk capacitor.

The invention belongs to the technical field of pole-mounted circuit breakers in power systems, and particularly relates to a pole-mounted circuit breaker integrating electricity taking and traveling wave distance measurement. The high-voltage fuse is connected with an integrated capacitor or a high-voltage sampling capacitor, and the high-voltage sampling capacitor is arranged on a wire inlet side and a wire outlet side; the integrated capacitor is arranged on the wire inlet side in the A-phase solid-sealed polar pole and the B-phase solid-sealed polar pole, and is arranged on the wire outlet side in the C-phase solid-sealed polar pole; the integrated capacitor is connected with the secondary circuit module in the box body, the capacitors C2 and C3 are connected with the transformer T2 in series, the power frequency electricity taking transformer T1 is connected to the C2 and C3 in parallel, and the secondary side of the T1 is connected with the electricity taking circuit; the protection circuit is connected to the C3 in parallel; and the traveling wave acquisition circuit is connected with the secondary side output winding of the T2. According to the invention, self-power-taking power supply for the power distribution terminal and acquisition of voltage and current traveling wave signals for fault point positioning judgment are realized, the operation efficiency and reliability of the power distribution network are improved, and powerful guarantee is provided for construction of the intelligent power distribution network.

A system comprises: a high voltage (HV) direct current (DC) to DC converter (HVDC) including: one or more transformers; a bridge driver connected to a primary side of the one or more transformers; and one or more bridge rectifiers connected to a secondary side of the one or more transformers, the one or more bridge rectifiers including one or more bridge rectifier switches; a low voltage (LV) DC to DC converter (LVDC) connected to the HVDC; and a boost converter including: an inductor connected to the one or more bridge rectifier switches; and one or more boost configuration switches operable, in combination with the one or more bridge rectifier switches, to configure the boost converter into each of a bypass configuration and a boost configuration, to regulate a voltage at the LVDC.

The invention relates to an energy consumption control method and device for a data center cooling system, equipment, a storage medium and a program product, and the method comprises the steps: obtaining the current operation state data of the data center cooling system, taking the minimization of the total energy consumption of the data center cooling system as a target, and predicting the energy consumption of the data center cooling system according to the operation state data and a target prediction model; a first flow parameter of a primary side water pump and a second flow parameter of a secondary side water pump in the data center cooling system are adjusted to obtain a first target flow of the primary side water pump and a second target flow of the secondary side water pump, and finally the current flow of the primary side water pump is adjusted to the first target flow. And the current flow of the secondary side water pump is adjusted to the second target flow. According to the method, the flow parameters of the primary-side water pump and the secondary-side water pump are adjusted in real time based on the target prediction model, so that the primary-side water pump and the secondary-side water pump operate in the optimal state and can flexibly cope with different operation environment changes, and then the accuracy of energy consumption control is improved.

A pulse generating system includes a primary capacitor positioned along a primary side of a pulse generating circuit, and configured to store electrical energy, and a primary switch positioned along the primary side. The pulse generating system also includes a pulse transformer configured to step up voltage from the primary side to a secondary side of the pulse generating circuit; an output capacitor; and a secondary switch positioned in the secondary side, wherein the output capacitor is electrically coupled to the pulse transformer through the secondary switch.

A direct-current conversion circuit, which is used for providing direct-current conversion between a first direct-current voltage and a second direct-current voltage is described. The direct-current conversion circuit comprises: a transformer, which comprises a primary-side winding and a secondary-side winding, wherein the primary-side winding comprises a center tap, and a first primary-side winding and a second primary-side winding, which are respectively connected to the center tap; a primary-side circuit, wherein a first side of the primary-side circuit is connected to the primary-side winding, a second side of the primary-side circuit comprises a first end, a second end, and a third end, and a first direct-current voltage is provided between the first end and the second end of the primary-side circuit; and a secondary-side circuit, wherein a first side of the secondary-side circuit is connected to the secondary side winding.