15 results about "Three phase system" patented technology

The invention discloses an electric energy quality disturbance positioning identification method based on phase perception and multi-mode fusion, and relates to the technical field of electric power system monitoring and fault diagnosis. The electric energy quality disturbance positioning identification method based on phase perception and multi-modal fusion comprises the following steps: acquiring an original voltage signal of a three-phase electric power system; extracting a sample embedding vector of each phase based on the original voltage signal, comparing the sample embedding vector with a normal sample vector, and determining a disturbance phase with power quality disturbance in combination with an adaptive threshold value; performing time sequence feature vector extraction and bispectrum image feature extraction on the disturbance phase, and performing alignment and collaborative fusion to obtain fusion features; the electric energy quality disturbance type is identified based on fusion features, phase-level positioning of the three-phase PQD is achieved, through an innovative phase perception embedding and prototype comparison mechanism, accurate and rapid positioning of abnormal phases in a three-phase system is achieved for the first time under the condition of not depending on disturbance phase labels, and the core pain point of a traditional method is solved.

The invention relates to the technical field of three-phase systems, and provides a three-phase voltage state estimation method and system based on virtual coordinates, and the method comprises the steps: calculating the voltage peak value of each phase for three-phase voltages, and determining that a phase is open if the peak voltage of a certain phase is lower than a threshold value in the three peak voltages; for three-phase voltage, virtual beta-axis voltage is generated through an all-pass filter, actual beta-axis voltage is obtained through Clark transformation, the product of the virtual beta-axis voltage and the actual beta-axis voltage serves as an evaluation function, and a positive sequence and a negative sequence are distinguished according to the positive and negative of the evaluation function. The system state can be accurately and effectively judged under the conditions of three-phase imbalance and voltage distortion, the anti-noise capability and the anti-harmonic interference capability are high, and safe and stable operation of equipment under the abnormal condition is ensured.

The present disclosure relates to a grid-connected inverter and a control method and device thereof, and a phase-coherent power supply system. The grid-connected inverter comprises a power supply circuit and an inductive auxiliary voltage dividing circuit, wherein the power supply circuit and the inductive auxiliary voltage dividing circuit are connected; the grid-connected inverter is configured to boost the output voltage of an alternating current power supply; the power supply circuit comprises at least one single-phase power supply circuit, wherein each single-phase power supply circuit is connected with the inductive auxiliary voltage dividing circuit. The present disclosure provides a common-ground inverter with reduced switch quantity, the inverter of the present disclosure has a boosting characteristic, and can be extended to a three-phase system while maintaining the common-ground characteristic of the inverter.

A three-phase UPS system (1) comprises a rectifier (100) and a battery (200). The rectifier (100) has an input side (101) being connectable to an AC power system (2) to provide first input power and to the battery (200) to provide second input power to the rectifier (100). The rectifier (100) has an output side (102) to provide a DC output power in response to a power share of the first input power and the second input power. The rectifier (100) is configured to be controlled such that the power share is adjustable.

The application belongs to the technical field of electric power, and relates to a constant-voltage three-phase capacitor wireless power transmission circuit and a parameter design method. The three-phase capacitor wireless power transmission circuit comprises a high-frequency three-phase inverter, three LCL input resonance compensation networks, three compensation inductance and capacitor plates, three CLC output resonance compensation networks and a three-phase uncontrolled rectifier. In the parameter design method, firstly, actual requirements and circuit structure parameters are determined; secondly, compensation network constraints and gains are determined; and finally, considering parameter robustness and operation efficiency, the parameters are designed. Compared with a traditional single-phase CPT structure, the three-phase CPT structure has higher power transmission capacity, and the parameter design method effectively improves the robustness of the three-phase CPT system to parameter deviation, ensures constant voltage output in the entire load power range, and controls the output voltage deviation within ±5%.

The invention discloses a phase sequence identification method, device and equipment for a group three-phase system and a medium, and belongs to the technical field of energy storage, and the method comprises the steps: pulling up an IOBus when the phase locking of a power grid succeeds; when the host carries out successful phase locking on the power grid, the IOBus is pulled up, and when the host judges that the IOBus outputs a high level, a low-level pulse signal is sent to the IOBus when the zero crossing point of the power grid is detected; judging the time when the IOBus outputs the low-level pulse signal as the time when the host crosses the zero point, and judging the time when the power grid crosses the zero point as the time when the target slave crosses the zero point by taking the time when the host crosses the zero point as a reference; and determining phase sequences corresponding to the host and the two slaves according to the time of the target slave and the host at the zero crossing point. By means of the method, the problems that in an existing three-phase system, the phase sequence recognition result of each single-phase inverter is not high in precision, and the phase sequence recognition result is prone to interference can be solved.

The invention discloses a neutral point potential balance and common-mode voltage suppression method and device of a three-level dual three-phase system, and belongs to the technical field of motor control. The method comprises the following steps: acquiring a target modulation wave, sorting reference voltages according to the magnitude, and dividing the reference voltages into six sectors; zero-sequence voltage is calculated according to the sorted reference voltage; according to the zero-sequence voltage, duty ratios of a high level, a zero level and a low level in a carrier period are calculated; obtaining a zero level duty ratio adjustment amount d0 through a PI controller, and subtracting the zero level duty ratio adjustment amount d0 from the zero level duty ratio of the non-clamping phase to obtain a PWM sequence of each phase; performing phase shifting on the PWM sequence of each phase according to a preset phase shifting strategy to obtain a target modulation wave; and comparing the target modulation wave with the carrier wave to generate a target PWM signal, and controlling the three-level inverter. The unbalance of the neutral point potential at the inverter side is suppressed, and the influence of the common-mode voltage is suppressed.

The application provides a driving circuit for a three-phase system power switch device, the three-phase system comprises a power switch group corresponding to each phase, the power switch group comprises an upper bridge arm power switch and a lower bridge arm power switch, the driving circuit corresponds to the upper bridge arm power switch, the driving circuit comprises a capacitor voltage division circuit, a voltage stabilizing circuit and a push-pull driving circuit, the capacitor voltage division circuit is connected with two phases except the corresponding phase, the output end of the capacitor voltage division circuit is connected with the corresponding voltage stabilizing circuit, the push-pull driving circuit and the upper bridge arm power switch of the corresponding phase in sequence, direct power is taken from the three-phase power supply, and a stable direct current voltage is generated to reliably drive the power switch device. The application realizes efficient and reliable driving of the power switch device, and overcomes the limitations of the traditional driving circuit which depends on a heavy isolation transformer or a complex switch power supply.

The invention provides a driving circuit for a three-phase system power switch device, the three-phase system comprises power switch groups in one-to-one correspondence with each phase, each power switch group comprises an upper bridge arm power switch and a lower bridge arm power switch, the driving circuit corresponds to the upper bridge arm power switch, and the lower bridge arm power switch corresponds to the lower bridge arm power switch. The drive circuit comprises a capacitance voltage division circuit, a voltage stabilizing circuit and a push-pull drive circuit, the capacitance voltage division circuit is connected with two phases except the corresponding phase, and the output end of the capacitance voltage division circuit is connected with the upper bridge arm power switch of the corresponding phase through the corresponding voltage stabilizing circuit and the push-pull drive circuit in sequence. Power is directly taken from a three-phase power supply, and stable direct-current voltage is generated to reliably drive a power switch device. According to the invention, efficient and reliable driving of a power switching device is realized, and the limitation of dependence on a heavy isolation transformer or a complex switching power supply in a traditional driving circuit is overcome.

The application discloses a zero sequence injection modulation method of a modular multilevel matrix converter and relates to the technical field of power electronic control. The modular multilevel matrix converter is connected with two AC systems with different frequencies; the method comprises the following steps: obtaining modulation wave components of three-phase systems on input and output sides respectively through capacitor voltage outer loop control and input current inner loop control of a sub-converter and overall output current control; for each bridge arm, corresponding modulation waves are calculated based on the two modulation wave components; a zero sequence modulation voltage is calculated based on the modulation wave components of the three-phase system on the input side; the zero sequence modulation voltage is injected into each modulation wave to obtain a zero sequence modulation wave; all the zero sequence modulation waves are modulated by using a carrier wave to generate trigger pulses which are distributed to switch devices of corresponding bridge arms. The method can expand the linear modulation range and operation range of the modular multilevel matrix converter and improve the utilization rate of capacitor voltages of sub-modules by injecting zero sequence components into modulation waves.

The application relates to the technical field of power switches, and discloses a three-phase synchronous drop type fuse device and method, which comprises a top shell, the lower surface of the top shell is fixedly connected with a resistance assembly, the bottom end of the resistance assembly is fixedly connected with a base, the lower side of the resistance assembly is fixedly connected with a supporting shell, the outer side of the supporting shell is fixedly connected with an insulating support, the inner side of the supporting shell is rotationally connected with a fuse tube, the outer side of the fuse tube is slidably connected with a sliding sleeve, the lower surface of the top shell is fixedly connected with an adjusting assembly, the lower side of the adjusting assembly is rotationally connected with a sliding rod, the top end of the resistance assembly is externally provided with a fixing assembly, and the rotationally connected position of the fuse tube and the supporting shell is provided with a protection assembly. Through the cooperation of the sliding sleeve, the sliding rod and the adjusting assembly, when the fuse tube drops due to abnormal current, the action of the single fuse tube can be synchronously transmitted to the other two phases of the three-phase system, so that the reliability and stability of circuit protection are improved.

The present invention relates to a heating panel which allows the state of each heating element to be easily monitored in order to quickly recognize faults and take actions by replacing the panel inside the heating module. The heating panel is reliable in height and easy to maintain. The heating panel (P) comprises at least one heating element (T) formed by resistors (R1, R2, R3) of a triple interconnected in a star pattern wherein each free end of each resistor (R1, R2, R3) of said triple receives electrical energy from a different phase of the three-phase system and is connected to the first bus (3) by at least one controlled switch (SCR, 4). A first control switch (2A) is interposed between the controlled switch (SCR, 4) and the first bus bar (3). Furthermore, the first bus (3) is connected to the at least one transformer (1) via at least one second control switch (2B). The star center (CS) of the triad (R1, R2, R3) is in turn connected to a second busbar (8). Furthermore, a current measurement device (6) is provided between or along the star center (CS) of the triad (R1, R2, R3) and the second busbar (8) in order to detect the intensity of a possible current passing through the star center (CS) of the triad, and wherein a control unit (PLC) is provided which is adapted to receive measurement data from the current measurement device (6), in this way, the state of the heating panel (P) is monitored.

The invention relates to a method for operating a drive unit (1000) comprising an electric machine (1) and a power converter arrangement (100) for supplying the electric machine with electrical power. The power converter arrangement comprises a first DC voltage terminal (101) and a second DC voltage terminal (102) and at least two half-bridges (110, 120, 130). In each half-bridge, a first and a second semiconductor switch (111, 121, 131, 112, 122, 132) are arranged between the first or second DC voltage terminal (101) and a center terminal (113, 123, 133) of the half-bridge (110, 120, 130). Furthermore, at least two half-bridges comprise a current sensor (114, 124) configured to measure the current flowing through the center terminal.In this method, a symmetrical three-phase system is produced, and the current intensity profile of the flowing current is recorded by each current sensor for a first time interval. Subsequently, a correction factor for the current intensity is determined for at least one of the at least two half-bridges as a function of a characteristic parameter of the recorded current intensity profiles, and the drive unit is operated using the determined correction factor. The invention further relates to a drive unit.

The invention relates to the technical field of unit converters, in particular to a full-power converter system for a variable-speed pumped storage unit and a control method. The M3C circuit topological structure adopts a modular matrix type converter framework and comprises a plurality of sub-converter units; the operation control strategy module is integrated with a double-closed-loop decoupling control framework, comprises an outer-loop control unit and an inner-loop control unit, and coordinates regulation and control of current, voltage and power. Three sub-converters in star connection are adopted to form a nine-bridge-arm matrix structure, each bridge arm is formed by cascading H-bridge sub-modules and connecting the H-bridge sub-modules with inductors in series, and flexible interconnection of a primary-side three-phase system and a secondary-side three-phase system is achieved; a double-closed-loop decoupling framework is integrated in control, and power, direct-current capacitor voltage and alternating-current voltage amplitude are accurately regulated and controlled through combination of outer-loop fuzzy PI online setting and inner-loop model predictive control.

The invention discloses an electric shock identification method, system, equipment and medium for a 110kV and above neutral point direct grounding system, and belongs to the technical field of power system fault identification, and the method comprises the steps: collecting a current signal in a three-phase system, and carrying out the transformation processing to construct a three-dimensional time-frequency amplitude spectrogram, so as to extract frequency band features; inputting the preprocessed spectrogram into a ResNet101 branch and an LSTM branch, extracting spatial texture and time sequence evolution characteristics, and fusing the spatial texture and time sequence evolution characteristics into a high-dimensional vector; and further generating high-dimensional discrimination features based on the vector, and realizing state recognition and fault classification through a classification decision process. According to the method, the structural difference of a single-phase system and a three-phase system is adapted, the configuration of a signal acquisition channel is optimized, the current characteristics are mainly extracted, and the time domain flux behavior of a 0.5-2k omega human body impedance interval is accurately modeled, so that the effective unification of the identification precision, the real-time performance and the engineering deployability is realized.