299 results about "Copper loss" patented technology

The invention belongs to the technical field of power system control, and discloses an intelligent adjusting system and method for a transformer. The method comprises the following steps: inputting transformer operation data and weather data collected in real time into a pre-trained load prediction model to obtain predicted load data; inputting the acquired physical parameters and operation data and preset calibration parameters into a pre-constructed digital twinborn model to obtain a cooling capacity index; calculating the total heat source power of the copper loss and the iron loss according to the predicted load data and the electrical parameters of the transformer collected in real time, and dynamically quantifying the balance state of the total heat source power and the cooling capacity index through a matching degree evaluation function in combination with the cooling capacity index to obtain a matching degree evaluation index; and the problem of dynamic unbalance between the heat dissipation capability of the transformer and the load demand in an extreme environment is systematically solved.

The invention relates to the technical field of electromagnetic coils, in particular to a laminated special-shaped plane spiral coil winding. The laminated special-shaped planar spiral coil winding is composed of at least two coil layers, and each coil layer is composed of a single special-shaped planar spiral coil. The inner ring part of the special-shaped plane spiral coil is a concentric plane spiral coil, and the outer ring part of the special-shaped plane spiral coil is a tooth-shaped spiral coil extending along the outer periphery of the concentric plane spiral coil; all phases of the coil winding are different in layer, the electrified magnetic field center of each coil layer deviates from the geometric center, and the projection of the magnetic field center of each phase in the plane of the coil winding is in central symmetry distribution. The invention innovatively provides a laminated special-shaped planar spiral coil winding, and provides a squirrel-cage equivalent rotor on the basis of the laminated special-shaped planar spiral coil winding, so as to provide competitive choices for reducing copper loss and improving heat dissipation, magnetic conductivity, structural strength and economic cost of an axial flux motor winding.

The utility model relates to a water-cooling outer rotor flat wire winding motor, belongs to the technical field of motors, and solves the problems of low slot fullness rate and high stray inductance caused by using round wire parallel winding fractional slot concentrated windings in the prior art. The motor comprises a stator assembly, a rotor assembly, a bearing and a water cooling system, and the stator assembly is located on the radial inner side of the rotor assembly; a bearing cover and an outer ring of the bearing are fixedly connected with the stator assembly, and an inner ring of the bearing is fixedly connected with the rotor assembly; the stator assembly comprises a stator base, an iron core assembly and a stator sealing piece, the iron core assembly is fixedly arranged on the stator base, the iron core assembly is of a partitioned structure and comprises a plurality of tooth parts, yoke parts and windings, and the windings are flat wire windings; the water cooling system is disposed adjacent to the stator assembly. According to the utility model, the block type stator and the flat wire winding are used for the external rotor motor, the slot space factor of the motor is improved, the copper loss of the motor is reduced, and the three-phase consistency of the inductance of the motor is improved.

The invention discloses a slotless permanent magnet motor based on a Halbach array, and belongs to the technical field of motor design and manufacturing. A rotor of the slotless permanent magnet motor is coaxially arranged in a stator, the stator comprises a stator iron core and a stator winding, the rotor comprises a permanent magnet and a rotor iron core, the permanent magnet is fixed on the outer wall of the rotor iron core and adopts a two-section Halbach array, the permanent magnet is composed of an auxiliary magnetic pole and a main magnetic pole, and an air gap is arranged between the stator iron core and the rotor. The stator winding is suspended in the air gap; during parallel magnetization, the magnetization directions of the permanent magnets of the Halbach array are along the tangential direction of the rotor, the magnetic pole directions are the same, and the main magnetic poles and the auxiliary magnetic poles both adopt a parallel magnetization mode; during radial magnetizing, the magnetizing direction of the permanent magnets of the Halbach array is in the radius direction of the rotor, the polarities of the adjacent permanent magnets are alternately arranged, the main magnetic poles adopt a radial magnetizing mode, and the auxiliary magnetic poles adopt a tangential magnetizing mode. According to the slotless permanent magnet motor, through directional magnetic field superposition of segmented magnetic poles, reverse magnetic leakage is reduced, air gap flux density is improved, and copper loss and iron loss are reduced.

The invention relates to the technical field of electrical mechanical parameter measurement, in particular to a slip ratio measurement method of a three-phase asynchronous motor. The method comprises the following steps: carrying out temperature gradient analysis and copper loss temperature rise ratio calculation on the three-phase asynchronous motor to obtain a thermal feature vector; carrying out air gap area capacitance measurement on the motor stator to obtain a fusion capacitance signal; performing rotor period feature extraction on the fused capacitance signal to obtain a rotor slot frequency feature spectrum; performing thermal field-capacitance field characteristic correlation on the thermal characteristic vector and the rotor slot frequency characteristic spectrum to obtain a characteristic correlation matrix; performing double-field reliability weight dynamic allocation under different working conditions according to the feature correlation matrix to obtain a fusion credibility index; and calculating an initial slip rate estimated value based on the thermal feature vector and the rotor slot frequency feature spectrum to obtain a dual-source slip rate value. According to the invention, the precision and accuracy of slip ratio measurement in a variable-temperature environment are significantly improved through an electrical mechanical parameter measurement technology.

The invention discloses a stator assembly, a compressor and refrigeration equipment, and relates to the technical field of motors. The stator assembly comprises a stator core formed by stacking a plurality of amorphous alloy sheets, the stator core comprises a yoke part, a tooth part and a shoe part, and the stator core is formed by stacking a plurality of amorphous alloy sheets, so that the iron loss of the stator assembly can be reduced. For a motor, the area of a stator slot is expected to be as large as possible to increase the winding wire diameter so as to reduce copper loss, and the smaller the minimum width of a tooth part is, the better is, but the smaller the width of the tooth part is, the more likely to cause magnetic field saturation. In order to reasonably design the minimum tooth width of the tooth part so as to reduce the problem of magnetic voltage drop increase caused by magnetic field saturation, the minimum tooth width Wt of the tooth part is set in a range of 2piD / 9Q to 2piD / 3Q, so that the area of the stator slot can be effectively increased, the problem of magnetic voltage drop increase caused by magnetic field saturation can be improved, the magnitude of current can be reduced, and the service life of the stator slot can be prolonged. The working efficiency of the motor is improved.

The invention provides a biphase composite magnetic material magnetically controlled reactor electromagnetic transient simulation method, device and equipment and a medium, and relates to the technical field of power equipment magnetic material testing and electromagnetic transient simulation. According to the invention, the test winding is arranged on the excitation winding of the magnetically controlled reactor, and multi-dimensional means of obtaining total iron loss through an open circuit test, obtaining magnetic hysteresis loss through a frequency reduction test, obtaining copper loss and leakage reactance through a short circuit test and the like are combined, so that separation of magnetic hysteresis loss, eddy current loss and additional loss can be realized; a high-fidelity hysteresis loop and a magnetic conductivity change rule are obtained, and the nonlinear characteristic and hysteresis response of the magnetic core can be accurately captured, so that the predictive capability of equipment performance and the sensing capability of an operation state are improved.

The invention relates to the technical field of electromechanical hydraulic systems, and particularly discloses a low-temperature cold start control method based on high-frequency injection, which comprises the following steps: analyzing a motor state, and carrying out observation and feed-forward compensation on disturbance caused by the motor state to a load torque and a viscosity coefficient through a sliding mode observer algorithm; according to the motor state, obtaining a state equation, constructing an extended sliding mode observer equation, deriving to obtain an observer error equation, and observing the load torque; analyzing the obtained load torque, wherein the motor load torque reflects the oil viscosity; high-frequency current injection, injection frequency control, skin effect enhancement and current amplitude control are carried out in a low-temperature state according to an oil viscosity result, copper loss and a high-frequency magnetic field eddy current effect are used for assisting heat generation, and according to a final oil viscosity result, when electromagnetic heat generation viscosity is reduced and a load is reduced, an injection voltage amplitude is gradually reduced. And after a normal starting condition is reached, switching to normal id = 0 control.

The invention discloses an intelligent monitoring method and device for operation energy efficiency of a transformer. The method comprises the following steps: acquiring multi-dimensional time sequence data such as iron loss and copper loss of the transformer; generating a cross-domain influence factor or a cross-domain influence matrix for quantifying the cross-domain correlation strength of the iron loss and the copper loss by calculating a cross-correlation function between related time sequences of the iron loss and the copper loss; and the correlated quantitative features are fused with the standardized loss trajectory and the working condition parameters, and a machine learning prediction model is constructed, so that a hidden fault mode of'iron loss-copper loss cross-domain correlated degradation 'in which the copper loss is driven to abnormally increase by iron loss deterioration is identified and early warned. According to the method, the defect of isolated analysis of loss in the traditional technology is overcome, early warning and traceability of a specific composite fault can be realized, and the safety and reliability of operation of the transformer are remarkably improved. The invention further provides a device for executing the method.

The invention discloses a winding laminated structure design method and device for optimizing high-frequency copper loss of a planar transformer. The method comprises the steps that 1, parameters of a to-be-optimized planar transformer winding are determined; 2, a lamination combination is arranged for the windings, the number of copper layers corresponding to the windings and the number of turns of the windings in the copper layers are determined, and the copper layers have no sequential relation; 3, the current amplitude and phase of each copper layer in the lamination combination are calculated, the currents of the copper layers are sequentially connected in a vector mode on a complex plane according to an optimal path, a local optimal lamination structure is obtained, and the optimal path judgment basis is that after the current vectors of the copper layers are connected end to end, the sum of squares of the distances from the end points of all the vectors to the original point is minimum; 4, calculating the copper loss of the local optimal laminated structure based on a preset high-frequency copper loss analysis model; step 5, setting different lamination combinations for the windings, and repeating the step 3 and the step 4 until all possible combinations are traversed; and step 6, comparing the local optimal laminated structure copper loss corresponding to all combinations, and selecting the copper loss with the minimum copper loss as the global optimum. According to the method, high-frequency skin and proximity loss can be effectively inhibited, and high-frequency copper loss is reduced.

To improve power efficiency of a synchronous motor in a wide speed range from a low speed to a high speed.SOLUTION: In a pole-number switching method, the current value of AC current supplied to an armature is reduced at low speed by increasing the number of poles and increasing the torque multiplier of the electric motor, thereby reducing copper loss, and loss at high-speed rotation (mainly iron loss) is reduced at high speed by decreasing the number of poles and lowering the voltage and frequency of the AC current supplied to the armature. Furthermore, a further power-efficiency improvement effect is provided by connecting the circuit such that, during driving of the electric motor, inverter power-supply current of an armature winding becomes a power supply for a field winding, and such that, during regenerative braking, current generated from the armature winding is regenerated to a battery efficiently.SELECTED DRAWING: Figure 2

The invention discloses a multi-switch tube open-circuit fault-tolerant method and system for a dual three-phase permanent magnet motor system, and the method comprises the steps: calculating a current compensation value of a healthy phase through employing a Lagrange multiplier method according to the open-circuit fault conditions of different switch tubes on the premise that the magnetomotive force of a motor before and after a fault is not changed, and employing the minimum copper loss as a constraint condition; adding a corresponding phase current compensation value to each healthy phase so as to obtain a corresponding fault-tolerant reference current; coordinates of the sampled phase current and the fault-tolerant reference current under the fault condition are converted to a rotating coordinate system, and the reference voltage of each plane is solved through PI closed-loop control; and pulse waveforms generated by each plane reference voltage under a natural coordinate system act on the switch tube by using a carrier pulse width modulation strategy, so that fault-tolerant control of the open-circuit fault of the switch tube of the dual three-phase permanent magnet motor driving system is realized. According to the invention, fault-tolerant control under various switch tube open-circuit fault conditions is realized, and the reliability of the motor driving system under fault operation is improved.

The invention discloses a performance analysis method for a topological structure of a multi-topology axial flux permanent magnet motor based on electromagnetic-thermal coupling, and the method comprises the steps: firstly building three-dimensional electromagnetic finite element models of four typical axial flux permanent magnet motors, and calculating electromagnetic loss including iron core loss, copper loss and permanent magnet eddy current loss; importing the loss data into a three-dimensional fluid-thermal coupling model, and simulating the temperature rise of the motor under a natural cooling condition; the performance of the motor is subjected to double constraints of winding insulation and irreversible demagnetization temperature of a permanent magnet, so that the maximum current density of safe steady-state operation of the motor is determined and identified by adopting an iterative electromagnetic-thermal coupling analysis method, and the maximum torque density of each topological structure is evaluated under thermal constraints. The electromagnetic performance and the thermal constraint can be coupled, so that the optimal performance achieved by different axial magnetic flux permanent magnet motor topological structures can be compared, and the problem of inaccurate performance evaluation caused by neglect of the thermal constraint in the existing motor design is solved.

The invention relates to the field of motor control, and discloses a synchronous reluctance motor magnetic circuit saturation compensation and current constraint control method, which comprises the following steps of: estimating a total stator flux linkage on line by adopting a self-adaptive gain generalized flux linkage disturbance observer so as to compensate a magnetic saturation effect; meanwhile, through a constraint gradient projection current optimizer, based on a unified torque tracking and copper loss minimization cost function, an optimal instruction meeting current constraint is generated in real time; the gradient norm and the constraint activation state are extracted from the interior of the optimizer to serve as system working condition characteristics, a cooperative adjustment mechanism is established accordingly, and the gain bandwidth of the observer is dynamically adjusted, so that the observer is quick in response in the dynamic state, high in precision in the steady state and high in noise immunity; therefore, it is ensured that the motor can achieve high-precision torque control and efficient energy conversion in a wide working condition range.

The invention discloses a smooth transition method and system for sensorless field directional control, and relates to the technical field of permanent magnet synchronous motor sensorless control. According to the method, an error between an I-f starting virtual synchronous reference coordinate system and a sensorless observer estimation coordinate system is eliminated through a dual-core mechanism of a robust transition strategy and a position error compensation strategy, and then rotor position deviation caused by non-ideal factors is corrected through an exclusive compensation module; the system constructs a multi-stage switching control framework based on the method, and seamless transition from I-f open-loop starting to sensorless FOC closed-loop control is achieved. Complex parameter adjustment is not needed, transition is fast and stable, torque magnetic flux control precision can be optimized, copper loss is reduced, system efficiency and robustness are improved, and the method is suitable for industrial driving scenes such as air conditioner compressors.

The utility model belongs to the technical field of electronic components, and discloses a combined type single-phase large-current flat wire vertically-wound differential-mode and common-mode integrated inductor which comprises a mounting base, a common-mode magnetic core, a differential-mode magnetic core, a winding coil and an insulating partition plate, the common-mode magnetic core is arranged on the upper portion of the mounting base, and the differential-mode magnetic core is arranged on the lower portion of the mounting base. The differential-mode magnetic cores are arranged at the two ends of the upper top face of the common-mode magnetic core, the winding coils are wound around the differential-mode magnetic cores and the common-mode magnetic core at the two ends and share the winding coils, pins at the two ends of the winding coils at the two ends are inserted into the mounting base, and pins at the two ends of the common-mode magnetic core are inserted into the mounting base. And an insulating partition plate for isolating the winding coils at the two ends is arranged in the center of the mounting base. According to the utility model, the common mode magnetic core and the differential mode magnetic core use the common coil, so that the purposes of reducing copper loss and reducing the size of the inductor are achieved, and the inductor has the advantages of differential mode performance, common mode performance, weight reduction and low copper loss.

The invention discloses a transformer magnetic powder core, a transformer device and a preparation method of the transformer magnetic powder core. The coating covers the surface of the magnetic powder core base body; the coating comprises a resin matrix and magnetic powder dispersed in the resin matrix, and the volume ratio of the magnetic powder in the coating is 3%-50%. The magnetic powder is added into the surface coating, so that the overall inductance value of the magnetic core is effectively improved, the increase of cost and copper loss caused by a method for increasing the inductance value by increasing the number of winding turns is avoided, and meanwhile, the coating also maintains good insulation and voltage-resistant performance and adhesion performance. Compared with a traditional scheme, the transformer magnetic powder core which is smaller in size, higher in inductance value and conversion efficiency and better in bias performance can be prepared.

The invention discloses a multi-loss measurement device and method based on an equivalent real motor rotor magnetic field, and relates to the technical field of motor measurement. The invention aims to solve the problem that the specific value of each loss cannot be accurately obtained when the motor performance is analyzed and the design is optimized in the prior art. The method comprises the following steps: preparing a rectangular stator iron core with the same polar distance or pitch as a tested motor, and arranging excitation iron cores at groove openings of grooves at two ends; applying current to the stator winding, acquiring terminal voltage and calculating resistance of the stator winding; applying current to the magnet exciting coil to form a leakage magnetic field, collecting the magnetic field intensity of each strand of the stator winding, constructing an associated equation of the current magnetic field, and further calculating strand current, circulation and total circulation loss in sequence. And calculating the basic copper loss by taking the average effective value of strand current in the stator winding. And calculating the total power loss through a pre-established model. And calculating stator iron loss according to an empirical formula. And obtaining the eddy current loss based on the stator iron loss, the total circulation loss, the basic copper loss and the total power loss.

The invention relates to the technical field of magnetic devices, and discloses a coupling inductor adjusting method, a coupling inductor and electronic equipment, the coupling inductor comprises magnetic cores, the two magnetic cores are oppositely arranged, and each magnetic core comprises a main magnet and winding middle columns arranged on the main magnet at intervals; the winding areas are arranged between the two magnetic cores at intervals, the winding middle columns and air gap pieces used for forming middle air gaps are arranged in the winding areas, and the air gap pieces are arranged between the winding middle columns of the two magnetic cores and connected with the winding middle columns respectively; at least one special-shaped winding coil is configured in the winding area, and is wound on the winding middle column; the leakage magnets are connected to the top end of the main magnet, and a top air gap is formed between the leakage magnets of the two magnetic cores. The copper loss of the coupling inductor is reduced, and the comprehensive performance of the coupling inductor is improved.

The invention discloses a torque ripple suppression method for a permanent magnet synchronous motor under a limited voltage, and belongs to the technical field of power generation, power transformation or power distribution. The method comprises the following steps: acquiring torque data changing along with a rotor position under different excitation currents, and establishing a torque three-dimensional look-up table model of the torque about a shaft current and the rotor position; respectively establishing optimization targets for a low-rotating-speed working condition and a high-rotating-speed working condition, and establishing a stator current two-dimensional table look-up model under the low-rotating-speed working condition and a stator current three-dimensional table look-up model under the high-rotating-speed working condition in combination with the torque three-dimensional table look-up model; an optimized stator current algorithm model is established according to the stator current look-up table model, the stator current two-dimensional look-up table model or the stator current three-dimensional look-up table model is switched according to the criterion of direct current voltage out-of-limit, and the query value of the optimized stator current is used as a stator current reference value for vector control of the permanent magnet synchronous motor. While low-speed copper loss reduction and high-speed speed regulation range expansion are taken into consideration, overall torque harmonic suppression under a voltage limited working condition is realized.

The present invention relates to the field of power technology, and particularly to a transformer fault inspection system and method based on multi-sensors. The system includes: a first acquisition module, a temporary determination module, a second acquisition module, an overheat determination module, a fault determination module, an adjustment module, and an early warning module. By collecting and comprehensively analyzing multi-dimensional data such as the flow rate of transformer cooling oil, acetylene content, winding temperature, DC resistance, and copper loss value in real time, the present invention can quickly locate faults, dynamically adjust detection parameters, and issue early warnings in a timely manner, improving the accuracy and efficiency of fault detection, reducing operation and maintenance costs and safety risks, enhancing the adaptability and stability of the system in complex environments, providing a strong guarantee for the reliable operation of power equipment, and overcoming the problems of inaccurate fault diagnosis and response delay caused by high-altitude extreme environments in the prior art through multi-parameter monitoring, dynamically adjusting thresholds, and optimizing inspection paths.

The invention provides an intelligent network connection reactive power energy management system, which belongs to the technical field of power system energy conservation and comprises an original low-voltage power supply system in a power grid, and I-type reactive power difference compensation equipment, II-type reactive power difference compensation equipment and III-type reactive power difference compensation equipment which are connected with the original low-voltage power supply system, the difference compensation results of the three reactive difference compensation devices are transmitted to the intelligent network connection technology platform through the remote transmission terminal; the I-type reactive compensation equipment is used for low-load compensation in a system transformer and reactive compensation of excitation and copper loss of the transformer; the II-type reactive compensation equipment is used for high-load reactive compensation in the system transformer; and the III-type reactive power difference compensation equipment is connected with the single electric equipment of which the load reactive power is greater than a specific value, and is used for reactive power in-situ difference compensation of the single electric equipment. Layered precise energy compensation is realized from the transformer to the terminal equipment, extensibility of macroscopic compensation is avoided, and compensation precision is greatly improved. Compared with the traditional problem that missing compensation is not easy to perceive, equipment abnormity and a compensation gap can be found in time, a fault point can be rapidly positioned, the pain point that maintenance is difficult to carry out in time is solved, and compensation continuity and stability are guaranteed.

The invention provides a variable reluctance motor temperature distribution prediction method and prediction system. The method comprises the following steps: dividing and modeling network nodes based on the structure and network precision requirements of a variable reluctance motor; calculating conduction thermal resistance and thermal capacity according to geometric parameters and material parameters of the motor; calculating air gap convection thermal resistance according to the motor working condition and the air gap viscosity coefficient; considering the relative position relationship between the armature winding and the excitation winding and establishing a complete variable reluctance motor thermal network model; calculating iron loss and copper loss by using an empirical formula based on state variables of actual operation of the motor, and taking the iron loss and the copper loss as input sources of the variable reluctance motor thermal network model; and iteratively solving the thermal network model of the variable reluctance motor by using a thermal transient equation to obtain predicted temperature distribution of the variable reluctance motor. The invention provides a complete modeling and prediction method suitable for temperature distribution of the variable reluctance motor, the calculation efficiency and precision are both considered, and powerful support is provided for multi-physics field joint optimization.

Disclosed are systems and methods for motor control using optimal efficiency reference generation. An electronic controller can determine current values of a motor in a rotating reference frame. Each current value can be associated with a dimension of a set of dimensions of the rotating reference frame. The electronic controller can further determine flux linkage values for each dimension of the set of dimensions of the rotating reference frame based on the current values using an optimization cost function that accounts for motor speed, copper loss, and core loss. The electronic controller can further determine target flux linkage values for each dimension of the set of dimensions of the rotating reference frame. The electronic controller can then control a power switch network coupled between a power source and the motor based on the flux linkage values and the target flux linkage values.

The application provides a motor winding, comprising: a multi-phase winding, each phase winding comprising a plurality of branches, each branch comprising: a forward coil group comprising a plurality of U-shaped coils, the span of the U-shaped coils of the forward coil group being y, y-2 or y+1, y representing a pole pitch of the motor; a reverse coil group comprising a plurality of U-shaped coils, the span of the U-shaped coils of the reverse coil group being y, y-1 or y+2; and a same-layer jumper with a span of y-2 or y+1, the same-layer jumper connecting the forward coil group and the reverse coil group; wherein the U-shaped coils of the forward coil group are connected in a circumferential direction for one turn and then connected in a radial direction to the next turn; the reverse coil group has the same winding mode as the forward coil group and has an opposite winding direction. The application improves the slot fill rate of the stator winding stator slot, reduces the resistance of the stator winding, reduces the copper loss of the motor, and improves the efficiency of the motor.

The present application relates to the technical field of transformer evaluation, and particularly relates to a light-weight medium-high frequency transformer conversion efficiency evaluation method and system, which comprises the following steps: obtaining structure winding parameters, light-weight parameters and operation condition parameters of a transformer to be evaluated, and constructing an evaluation data set; constructing an efficiency evaluation model, which at least comprises an iron loss sub-model and a copper loss sub-model, and setting model parameters of the iron loss sub-model and the copper loss sub-model as to-be-identified parameters; obtaining test data corresponding to the transformer to be evaluated, and performing parameter calibration on the to-be-identified parameters; inputting the evaluation data set into the calibrated efficiency evaluation model, outputting loss decomposition results and efficiency results of each working condition point, and obtaining conversion efficiency evaluation results. Through the present application, the problem that the efficiency evaluation of a light-weight medium-high frequency transformer in the prior art relies on experience or single-point testing and is difficult to model and calibrate in multiple working conditions, thereby leading to large deviation, is effectively solved, and accurate evaluation of multiple working condition loss decomposition and conversion efficiency is realized.

The utility model relates to the technical field of gear motors, and discloses a gear motor protection device which comprises a gear motor body, a connecting shaft is installed at the front end of the gear motor body, a sliding groove is formed in the surface of the connecting shaft, and a fixing plate is fixedly connected into the sliding groove. One end of the fixing plate is fixedly connected with a limiting rod, the tail end of the limiting rod is fixedly connected with the interior of the sliding groove, the surface of the limiting rod is slidably connected with a sliding block, the interior of the sliding groove is rotatably connected with an arc-shaped plate, and the top end of the sliding block is rotatably connected with a connecting plate. According to the gear motor protection device, automatic heat dissipation can be carried out when the gear motor main body runs, so that the gear motor main body can be kept at a moderate temperature when running, the aging of an insulating material, the copper loss of a winding and the damage of parts such as a bearing are reduced, and the effective protection of the gear motor main body is realized.

The utility model discloses a kind of power inductors, by the cooperation base assembly of a group of magnetic ring splicing into annular cylinder with prefabricated flat coil, wherein flat coil is annular winding with turn gap zero under prefabricated state, flat coil is reversed and folded to show fin ring under assembly state, two free ends of flat coil are extended in parallel in two states, magnetic ring is inserted in fin ring and is bonded to receive port, under the state that flat coil wraps closed loop magnetic ring, two free ends are penetrated and fixed to base. The inductor effectively solves the production problem of using flat wire to wind circular power inductor by optimizing the variable shape of flat coil prefabrication and assembly and splitting and splicing magnetic ring for embedded assembly, effectively improves the current-carrying capacity of inductor device, improves its DC-DC Converter Buck circuit conversion efficiency under the condition of reducing copper loss and iron loss.

The present invention relates to a distribution transformer, comprising a silicon steel core, a low-voltage coil, and a high-voltage coil. The low-voltage coil is wound around the core column of the core, and the high-voltage coil is wound around the outside of the low-voltage coil. The low-voltage coil is wound in a left-hand direction, and the high-voltage coil is wound in a right-hand direction. The tapping section of the high-voltage coil is located on the main airway side. The low-voltage coil is wound using copper foil, the width of the copper foil being greater than the reactance height of the high-voltage coil, and a nylon spacer is provided between the coil and the clamp. The present invention can effectively reduce the radial and axial electromotive forces borne by the coil, reduce the copper consumption of the coil, reduce copper loss, reduce transformer temperature rise, save energy, effectively ensure the fluidity of the transformer oil, improve the heat dissipation effect of the coil, improve the transformer's ability to withstand short circuits, and save wood.

The present invention discloses a highly efficient control method for a multiphase permanent magnet synchronous motor. Based on the extreme value search principle, a model of the electromagnetic torque and current vector angle of the multiphase permanent magnet synchronous motor is established. A virtual high-frequency signal is superimposed on the current vector angle, and an extreme value search process is designed. By detecting whether the partial differential of the electromagnetic torque term with respect to the current vector angle term is zero, the optimal current vector angle is searched. This method enables the multiphase permanent magnet synchronous motor to generate maximum electromagnetic torque under a certain current amplitude, thereby reducing motor copper loss. The highly efficient control method for a multiphase permanent magnet synchronous motor disclosed by the present invention has the advantages of a simple control structure, easy implementation, and low dependence on motor parameters.