News of network of global electric machinery: ? character
Move below drive of sine wave power source when electromotor when, pass electric machinery axis hand in change voltage of linkage generation axis. These linkage are by rotor and stator chamfer, detached core piece the directional attribute of the join part between, magnetic material and power supply source are lopsided wait for an element to cause magnetic flux lopsided and of generation [1> . To 90 time, when the PWM inverter that is power parts of an apparatus with IGBT regards electric machinery drive as power source, problem of electric current of electric machinery axis is more serious, and when its produce mechanism and drive of sine wave power source, differ completely. Document [1> points out, have frequency of tall carrier wave (for example 10kHz above) the attaint when the bearing that IGBT inverter brings about electromotor compares the inverter drive of small carrier frequency is faster. Relatively detailed ground analysed Busse the relation between the generation of bearing electric current and bearing current density and bearing attaint [2> , the model of circuit of bearing electric current that built PWM drive to fall, but this model fails to reflect the concern between a bearing electric current and inverter switch frequency. The generation mechanism that is voltage of axis of the electric machinery when discussing drive of voltage of pulse of high frequency PWM and axial electric current, the article is building the base of axial voltage and model of circuit of axial electric current, analytic axis electric current produces unripe condition and form, end has the characteristic change that outputs voltage in the light of inverter and electric machinery to wait for a circumstance without overvoltage, the axial voltage that falls through emulating an analysis to get different case and bearing electric current are undee.
Controlling aspect of bearing electric current, document [the method that 1> gives out changes PWM voltage into sine wave voltage with sine wave filter, make electric machinery job is below condition of sine wave power supply, but this method place strings together inductance big, systematic trends is answered slow, at the same time on inductance pressure fall to increase with power comsumption. The article strings together small inductance in inverter output end and complementary absorb a network with RC, can restrain the axial electric current that appears below PWM inverter drive effectively.
2 in all modular voltage and axial voltage
Think commonly, the main reason that effect of magnetic circuit disequilibrium, sheet pole and capacitance electric current are voltage of axis of the generation in electric machinery [3> . In the common electric machinery of power supply of electrified wire netting, people values the influence with lopsided magnetic circuit quite commonly. But voltage of the axis in the electric machinery in inverter power supply is main by voltage lopsided, namely the 0 foreword heft of power source voltage arises. As a result of circuit, yuan of parts of an apparatus, join and loop impedance lopsided, power source voltage produces zero shift inevitably, this voltage will produce 0 foreword electricity in the system, bearing is electric machinery the one part of 0 foreword loop.
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