Specifications1. Customised
2. good quality
3. 20 years manufacturing experience
4. Altitude: ≤1000m
Assume that during the T T 1 0 ~ G5, G6 conduction, dangling a photograph, as shown in figure 1 (a), is a phase back emf ea = U an (a) phase voltage phase, a phase voltage U ag = U + U ng = an ea + U ng. At t0 time, ea = 0, b and c two phase current, on the other hand, and that the impedance is equal, and by the small diesel generator back emf waveform is known: the eb + ec = 0, so U ng = 1/2 U d, so U ag = ea + U ng = 1/2 U d. As long as it can detect or U an U d (U ag - 1/2) of the zero point, can be indirectly detect the zero moment of ea. Because the testing point ahead of the next converter 30 °, can be after 1/12 inverter cycle delay, shut off the G5, trigger conduction G1, which can ensure the maximum average electromagnetic torque motor can continuously produce. Repeat the above process, detection of ea in turn another zero and eb, ec all zero, and also delay, in turn trigger conduction of generator set spare parts a, b, c three-phase bridge arm up and down, to ensure the correctness of the permanent magnet brushless dc motor reversing sequence.
Y2 series electric motor wholesale
Specifications
1. effiency: IE2 and IE1
2. 20 years manufacturing experience
3. 12 months guarantee
4. low noise and vibtration
5. AC Voltage: 220V/380V, 380V/660V,400V/690V,220V/400V
According to different detection objects, and the detection method can respectively called phase voltage method (test U an), the terminal voltage method (U ag). Among them, the terminal voltage method, the application of more. In terminal voltage method, in order to realize the phase voltage of zero crossing detection, first U ag, U can be the bg, U CG input low pass filtering devices, respectively, in order to eliminate the can seriously interfere with the back emf waveform, that there is no clear chopper signals passing zero [4]. And then use www.facebook.com/dongfeng.motor a voltage comparator, respectively each phase voltage compared to zero level, according to the comparison results of coding signal encoding, to get the rotor position signal. At present, the selection of zero level as shown in figure 2 [2], mostly by V, V b, V c three-phase symmetric star connection level V 0 instead of the center of the resistance of the circuit. Abroad recently put forward a new method: the three opposite electric potential (replace) with phase voltage first by square wave into a balanced three-phase sine wave, again through the star connection, get the central level, instead of a zero level. This method can get accurate "0" (zero after balanced three-phase sine wave synthesis), can reduce the position detection error.
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