Q:What is the control speed for ac servo motors?

Common way of servo drive speed have analog voltage control, namely by adjusting the servo drives the difference voltage at the input analog voltage control control servo motor running at different speed; Another is command control, which gives the servo the required speed through a given command. There is also a pulse signal control, which controls the speed of the servo motor through a pulse signal generator or another set of servo.

Q:How does the current transformer in ac motor work?

The differential protection of ac motor is in the three-phase power supply (cabinet) of the motor, which is equipped with three current transformer: A1, B1, C1. At the end of the three-phase winding of the motor, there are three current transformers: A2, B2 and C2, before being linked to "neutral". The six current transformers are the same, and the secondary winding receives the differential protection relay. When the motor is working, A1, A2 is equal to zero, the difference is zero, and the differential protection relay has no output. (B1, B2, C1, C2) The proposal: still seek a book to see, as the electrical design personnel, should have more in-depth understanding, the Internet is difficult to get.

Q:Comparison between ac motor and dc motor

Such high-pressure transport means that smaller wires can be used to save costs. search And because of that, the exchange of these frequencies, 50HZ 60HZ, is less expensive. So it suits our national conditions better However, ultra-high voltage, long-distance transmission, for example, these provinces, are dc transmission, dc transmission can be more efficient use of effective area of the wire, the main is pure in impedance and affect the efficiency of ac. But dc power normally just at a distance, such as China, so in general can be more cost savings, but need to build on both ends of the rectifier and inverter equipment will ac to dc and dc to ac grid. So if it's a distance transmission, the cost is too high. Only for long-distance transmission.

Q:What are the main parts of alternators?

?ends of the generator is aluminum alloy die casting, after the end cover with brush holder. Silicon diode rectifier is used will have a three-phase alternating current generator, rectifier dc. It is composed of six diode, respectively, pressure plate and the rear end cover in aluminum alloy component, a three-phase bridge rectifier circuit. x0d generator of the cathode by iron, perfectly on the back end cover three diode cathode tube, its shell is positive, three diode shell together become a generator of the cathode, the center for pipe cathode lead; In a component on a board of three diode as the anode tube, its shell is negative, the three diode shell meet together for the anode, the center lead to the anode of the pipe.

Q:What does the motor center of the three-phase ac motor mean

Center height refers to the height of the motor shaft to the base Angle of the seat. The length of the machine is used in the international letter of the letters: the "S" - the short stand, the M - the engine seat, the L - the long machine seat, is usually determined according to the length of the stator iron core. The "H" of 80 is 80mm

Q:Three-phase ac asynchronous motor load start and start up with airload start current who small, why?

Load start current is large, and load start consists of idle start current and load current.

Q:Which is good for dc motor and ac motor?

The family seems to be alternating current, so it should be alternating current. Direct current also seldom listens

Q:How does the three-phase ac motor identify the phase

The star delta launch is a time relay for three ac contacts String resistance and reactance start are now rare, and resistance is usually not in the distribution box The circuit of the auto-reducing voltage is a little bit closer to the star delta, but it is applied to the motor that is more than 90KW, and the auto-transformer is in or near the cabinet

Q:Three phase ac synchronous motor is different from three-phase ac asynchronous motor

Asynchronous motor stator into alternating current (ac), is to produce a rotating magnetic field, and the rotor magnetic fields generated by induction, so that the two magnetic field effect, make the rotor turns with the stator's rotating magnetic field. The rotor is slower than the stator rotating magnetic field, a slip, sync so called asynchronous machine. The rotor of synchronous motor is made by adding direct current to the same magnetic field, so that the rotor will follow the stator rotating field to synchronize with the other.

Q:Why does ac power connect capacitor

The purpose of ac motor capacitance is to transfer the single phase alternating current to a phase difference of 90 degrees. The two phase alternating current (ac) into two groups and four groups, each motor coil winding, is formed in the motor rotating magnetic field, rotating magnetic field to produce induced current in the motor rotor, rotating magnetic field and the magnetic field produced by induced current in the opposite direction, by rotating magnetic field into a state push-pull rotation.