531 results about "Copper loss" patented technology

In a multi-phase power converter, efficiency is increased and ripple reduced while maintaining transient response and dynamic performance improved by electrically coupling secondary windings of transformers or provided for inductors of respective phases such that current to a load is induced in each phase by current in another phase. Magnetic coupling can also be provided between phases using a multi-aperture core of a configuration which minimizes primary winding length and copper losses. Efficiency at light load is enhanced by controlling current in the series connection of secondary windings in either binary or analog fashion.

A transformer is provided with a coil portion containing primary windings and a secondary winding. Cores sandwich the coil portion. Each of these windings includes a toroidal-shaped portion that is formed by winding flat type wires in a toroidal shape and by overlapping these flat type wires. Edge portions of this flat type wire are derived from the toroidal-shaped portion respectively. A plurality of windings and the cores are arranged along an overlapping direction of the flat type wires. employed, By this structure, a copper loss caused by the skin effect can be reduced and the electromagnetic coupling conditions between the windings can be improved.

A compact, rugged, variable reluctance, variable speed, electric motor capable of producing high torque at high electrical energy conversion efficiencies is provided. The present invention provides for a multi-stage motor design having a number of discreet rotor and stator elements on a common shaft. This configuration provides for the simplest of magnetic structures and produces a powerful magnetic flux modelling design technique that is used to further optimize the motor design and subsequent control logic. Thermal mapping of the magnetic mass provides for advanced cooling techniques that are used to ensure long in-service life in the most extreme of industrial applications. The electric motor inherently provides low vibration thereby greatly reducing noise; low turn to turn voltage potentials thereby eliminating costly phase to phase shorting potential; efficient motor operation through the reduction in switching and copper losses in both the machine and its control system.

Provided is an annular reactor core formed of a U-shaped core and core legs. Core joints including end portions and two protrusions form the U-shaped core. Between the protrusions of these core joints, a plurality of (two) core legs 6 formed of core blocks are arranged so as to have gaps and the protrusions. The ratio A/B, which is a ratio of the length A of the protrusions of the core joint to the average length B of the core blocks constituting the core legs in a magnetic path direction, is optimized so as to be not less than 0.3 but not more than 8.0, whereby an increase in copper loss due to leak magnetic fluxes of the gap portions is suppressed.

A stator winding structure of a motor or a generator includes plural separate different-shaped rod conductors combined to form a collective winding structure to take the place of a conventional winding structure which has a coil wire wound continuously. The different-shaped rod conductors can be designed in shape to match with the sizes of the coil slots to increase a slot occupied rate of the conductors and to prevent the conductors from bent during the coil winding process. The stator winding structure is especially applicable to a motor or a generator with large power and difficult in multi-electrode winding, facilitating winding and enhancing a slot occupied rate of the conductors and also reducing copper loss during output of large current.

The invention discloses a transformer-free inverter, which comprises an input capacitor, six power switching tubes, six anti-parallel diodes and two filter inductors. The switching motion is performed by using the cooperation of the six power switching tubes and the anti-parallel diodes thereof, and then when the output voltage of the inverter has zero level, the output alternating current side and the input direct current side of the inverter are in a decoupling state so as to ensure that the common mode voltage of the inverter is kept constant when the output voltage of the inverter realizes three-voltage modulation and further fully eliminate the common mode current; the switching voltage on the power switching tubes is changed to be half of the direct current input voltage, so the switching loss of the power switching tubes is reduced; and the output current ripple wave of the inverter is further reduced through frequency doubling pulse width modulation, the output electrical energy quality of the inverter is improved, and the volumes of the filter inductors are reduced so as to reduce the copper loss and magnetic loss generated on the filter inductors.

The invention discloses a permanent magnet synchronous motor temperature rise heat dissipation analysis method based on the multi-field coupling technology. The method comprises the first step of carrying out the analysis of electromagnetic loss by the establishment of an electromagnetic field model of an electric machine to obtain the copper loss on a coil, the iron loss of an iron core and the eddy-current loss of permanent magnet materials, the second step of establishing a fluid solid strong coupling conjugate heat conduction model of the structural temperature field analysis and the fluid heat dissipation analysis of the electric machine, the third step of establishing a bothway weak coupling model of the electromagnetic loss and the fluid solid strong coupling conjugate heat conduction analysis, and the fourth step of achieving the convergence of a single physical model and the convergence of the load transferring between the electromagnetic field model and the fluid solid strong coupling conjugate heat conduction model by the adaptation of a repetitive cycle iterative method, wherein if the condition of the convergence meets the condition set by a user, the coupling is balanced, and the computing process is finished. The permanent magnet synchronous motor temperature rise heat dissipation analysis method integrates the advantages of the strong coupling and the weak coupling, the temperature rise and the heat dissipation process when the electric machine works are precisely simulated in a unified software platform, the stability of the convergence in the process of computing is enhanced, and computing precision and computing efficiency are improved.

The invention provides a bearingless switched reluctance motor and a control method thereof. The difference between a rotor pole arc angle and a stator pole arc angle of the motor is 15 degrees, current of torque windings and suspension windings are controlled to generate suspension force, the current of the torque windings is controlled so as to generate torque, and current of the torque winding of each phase and turn-on and turn-off angle of the torque winding are regulated to achieve a speed closed loop; radial displacement of a rotor is detection, and radial force needed for rotor suspension is outputted via PID (proportion integration differentiation) regulators, so that closed-loop control of radial displacement of the rotor is achieved. The suspension windings are only excited and conducted in a maximum-inductance flat-top area and do not generate torque, so that the torque and the suspension force can be decoupled in control, and current magnitude of the torque windings and the suspension windings is optimized to make copper loss of the windings to be minimum; in addition, counter potential of the suspension windings and the torque windings is zero in the maximum-inductance flat-top area, and high-speed suspended running of the bearingless switched reluctance motor is benefitted so as to give full play to high-speed adaptability of the switched reluctance motor.

The invention relates to a dynamic loss reduction method for a distribution network and a synthesized loss reduction system of a distribution network. A principle that an electric field and a magnetic field are mutually symbiotic and affected is applied for dynamically realizing electromagnetic balance; the treatment of'peak load shifting'is carried out on the current difference value between three-phase unbalanced currents caused by the dynamic unbalance of the power used by a three-phase load at the secondary side of a distribution transformer so as to lead the current difference value to approach balance, reduce a zero sequence current and the unbalance degree of the three phases, and restrain a harmonic, thereby realizing the self loss (loss on transmission) of the distribution transformer and the line loss (the copper loss of the line) at the first side and the secondary side of the distribution transformer; the synthesized loss reduction system of the distribution network realizes the synthesized loss reduction management of the distribution network, the loss on transmission of the distribution transformer as well as the automatic measuring and accounting on the data of the copper loss of the line at the first side and the secondary side thereof; the system also realizes the remote automatic collection on the power data of the distribution transformer in the same time as well as the accounting of the line loss of a distribution line, calculates and accounts the line loss of the distribution network, calculates and analyzes the loss reduction as well as analyzes the benefits of energy saving and emission reduction.

The invention discloses a method for the online detection and total loss determination of the neutral current of a distribution transformer. Four precise split core type current transformers are used for respectively detecting the three-phase current and the neutral current, each harmonic component is obtained by using fast Fourier transform, a fundamental current is calculated, and then the iron loss, the copper loss, the neutral line loss and the earth current loss of the transformer are calculated according to each current, thus obtaining the total loss of the transformer. The method can effectively monitor and acquire the electric signal of the transformer, a DSP high speed central processor performs digital filtering on the electric signal, the anti-interference capability is improved, and the neutral current of the transformer and loss caused thereby are measured on line, realtimely, rapidly and accurately, providing necessary basis for the safe and stable operation of the transformer.

A control device for a permanent magnet synchronous motor includes: an inverter 9 for converting inputted DC voltage into AC voltage of variable-voltage and variable-frequency, and driving a motor 14 with the AC voltage; a speed controller 22 for generating, in accordance with a speed instruction signal, a q-axis current component orthogonal to the magnetic field of the motor 14; a loss calculating means 50 for calculating a loss by summing a copper loss and an iron loss in the motor 14; a d-axis current generating means 52 for generating, in accordance with the value that is the motor's rated loss decreased by the loss, a d-axis current instruction signal to flow into the motor 14; and a resistor-on-judgment unit 58 for judging, from the DC voltage, whether or not the motor 14 operates in its recovery state and activating the d-axis current generator 52 while in the recovery state.

The invention provides a four-phase doubly salient motor, which belongs to doubly salient motors. The four-phase doubly salient motor consists of a stator and a rotor which are arranged around the same rotating shaft; 8n salient teeth are uniformly distributed on the stator; exciting windings are embedded or permanent magnet steel is arranged in slots at every four salient teeth on the stator; centralized armature windings are sleeved on the salient teeth of each stator respectively; the armature windings on the salient teeth at the same position in a magnetic field are connected in series with one another to form a one-phase winding; and 6n rotor poles are uniformly distributed on the rotor, wherein n is a positive integer and more than or equal to 1. A motor unit has an 8/6 structure. The polar distance of the stator is triple the arc length of a stator pole; and the rotor pole is as wide as the stator pole. When the rotor poles are widened until the polar arc coefficient is 1/3, the output power is maximum when the motor is used as a generator. Compared with a three-phase 6n/4n polar doubly salient motor, the four-phase doubly salient motor has higher power density, lower winding copper loss, wider speed regulation range and smaller torque pulse.

Disclosed is a vehicle rotating motor, comprising a stator which can not only inhibit the increasing of resistance and copper loss, but also inhibit the temperature of the peripheral coil end from excessively rising. Each phase winding is divided into a first a-phase winding (231), a first f-phase winding (281), a second a-phase winding (232) and a second f-phase winding (282). The first a-phase winding (231) and the first f-phase winding (281) extend in an axial direction in a groove (21c) and extend in a circumferential direction and enters the groove (21c) separating six slots, thereby a conductor wire (30) is winded at the inner periphery of each groove (21c) of the same groove group. The second a-phase winding (232) and the second f-phase winding (282) extend in an axial direction ina groove (21c) and extend in a circumferential direction and enters the groove (21c) separating six slots, thereby a conductor wire (30) is winded at the outer periphery of each groove (21c) of the same groove group. In addition, the axial length of the first a-phase winding (231) and the first f-phase winding (281) is shorter than that of the second a-phase winding (232) and the second f-phase winding (282).

The invention discloses a permanent-magnet bias outer rotor radial AC hybrid magnetic bearing. A stator core is arranged in the middle of the rotor core; the stator core is provided with 6 identical stator core magnetic poles, which are uniformly distributed in the circumferential direction and extend outwards in the radial direction; the three stator core magnetic poles, which are mutually isolated, are respectively provided with an slot; identical cuboid permanent magnets, which are used for providing static bias flux, are respectively embedded in the slots; the S pole of each permanent magnet faces the stator core, and the N pole faces the rotor core; the other 3 stator core magnetic poles, which are mutually isolated, are respectively wound by identical control coils; the top end of each stator core magnetic pole is provided with a groove; identical position sensors are arranged in the grooves; and control fluxes are formed among the stator core, radial air gap and rotor core. The invention reduces the magnetic resistance of the control magnetic circuit, lowers the coil copper loss and power amplification loss, has the advantages of small size and light weight and enhances the working efficiency of the magnetic bearing.

In a slotless permanent magnet rotary electric machinery, comprising a substantially cylindrical rotor (53) incorporated with a permanent magnet (52), a stator iron core (54) surrounding the rotor; and a coil (55) provided between the rotor (53) and stator core (54) in a spaced relationship with respect to the rotor (53), the coil (55) comprises a plurality of turns which are shifted from one turn to another along the circumferential direction in a mutually overlapping manner; and the coil turns are formed by a conductor (60, 60a, 60b) having an elongated cross section, a long axis of the cross section extending in a radial direction. This provides rotary electric machinery which can significantly reduce loss in a high speed range without substantially increasing copper loss.

The invention discloses a five-phase magnetic flow switching motor fault-tolerant control method based on a minimum copper loss principle. According to specific circumstances of no-load counter potential of a motor, a current control mode consistent with the wave shape of the counter potential is adopted in the process of normal operation. When a system has a default-phase fault, electromagnetic torque is kept unchanged, a non-fault-phase fault-tolerant current formula under the condition of the minimum copper loss is worked out, the worked-out harmonic current is used for carrying out one-phase and two-phase fault-tolerant control on the motor, average output torque before an open-circuit fault of the motor and average output torque after the open-circuit fault of the motor are kept equal, the output torque in the fault and the output torque in the normal operation state are equivalent, and torque ripples and copper loss of windings are reduced. Compared with a traditional fault-tolerant control method, the five-phase magnetic flow switching motor fault-tolerant control method based on the minimum copper loss principle lowers the copper loss by 4.3% in the process of one-phase open-circuit fault tolerance, and lowers the copper loss by 12.9% in the process of fault tolerance of two adjacent phases.

The invention discloses a single-phase three-level inverter, which comprises an input capacitor, six power switches, two freewheel diodes and a single-phase output filter. The inverter performs switch motion by utilizing the six power switches and the two freewheel diodes cooperatively, so that when the output voltage of the inverter is a zero level, an output alternating current (AC) side and aninput direct current (DC) side of the inverter are positioned in a decoupling state; therefore, the output voltage of the inverter realizes three levels, the common-mode voltage of the inverter is a constant, and common-mode current is completely eliminated. The problem of imbalanced capacitor voltage caused by parasitic capacitance of a power switching device is solved in the circuit; therefore,a working mechanism without leakage current cannot be damaged, and the control means is simple; moreover, the circuit and a dead-zone working mechanism are reliable, and the working stability of the circuit is high. Due to the adoption of a unipolar pulse width modulation mode, the output current ripple of the inverter is low, copper loss and magnetic loss on a filtering inductor are low, and thequality of the output electric energy is high.

A high performance rotating electrical machine which aims at downsizing, and challenges inevitable technical problems such as deterioration of efficiency η caused by copper loss and temperature rise inside the rotating electrical machine due to heat generation induced by eddy current generated in magnetic body.

The invention discloses a default phase fault-tolerant control method of a nine-phase flux-switching permanent magnetic motor. The default phase fault-tolerant control method includes that redundancy characteristics and harmonic current of a nine-phase system are utilized to compensate a fault-tolerant control strategy; when a motor winding or a driving system is in a default-phase failure caused by one-phase circuit breaking or circuit shorting, by online calculating third, fifth and seventh harmonic current momentary values under copper loss minimum boundary conditions in real time and performing closed-loop decoupling control on the harmonic current, the motor can be smoothly transited from a nine-phase normal state to an eight-phase fault state and maintain both output rotating speed and rotating torque to be unchanged, undisturbed running of the driving system is realized, and requirements, of high-reliability application fields like track traffic and electromobiles, on system continuous running capability are met; during designing of the nine-phase flux-switching permanent motor, electromagnetic torque pulsation rate is lowered while high torque density of the special motor is retained.

A two-phase switched reluctance machine is provided using discontinuous core structures as the stator for low-cost, high-performance drives. This discontinuous stator core structure contains short flux paths and maximum overlap between the rotor poles and stator poles in the stator discontinuous core structures, regardless of the rotor position. Example configurations of such core structure include E-core, L-core and I-core configurations. Using less steel and magnet wire than in conventional SRM designs results in cost savings of stator material and winding material. Efficiency of this novel SRM is improved because of shorter flux paths resulting in reduction of core losses and decreased phase resistance resulting in reduction of copper losses. Two-phase simultaneous excitation of the novel SRM can reduce torque ripple during commutation as compared with existing two-phase SRMs.

The invention relates to an inductor and a manufacturing method thereof. The inductor comprises a closed magnetic loop magnetic core and a coil, wherein the closed magnetic loop magnetic core consists of non-E-type magnetic core bodies and takes the shape of a Chinese character 'ri'. The manufacturing method of the inductor comprises the following steps of firstly arranging an insulating layer on a magnetic core column which needs winding of the magnetic core at the central column, with the thickness less than 0.5 mm, and then according to the required number of circles, sequentially winding by using single-stranded enameled wires or multi-stranded intertwisted enameled wires; after winding the enameled wires, butt jointing the magnetic core at the central column and the magnetic core at the side column into the closed magnetic loop magnetic core body taking the shape of the Chinese character 'ri'; and tightly binding up the outer side of the magnetic core body by using insulating tapes, so as to lead the magnetic core at the central column and the magnetic core at the side column to be butt jointed tightly and firmly. The invention has the beneficial effects that: compared with the traditional inductor with the coil, the single-stranded enameled wire length of the winding coil is reduced, the number of windings is greatly reduced, and the copper material is saved by over 10 percent; simultaneously, the diffusion magnetic flux can be minimized so as to decrease the copper resistance and copper loss of the inductor, and the temperature rise of the inductor is decreased accordingly, thus saving both materials and electrical energy, and prolonging the service life of the product simultaneously.