A speed regulating synchronous motor unit

Abstract

The invention discloses a speed-regulation synchronous motor assembling unit which comprises a synchronous motor and a controller, wherein the synchronous motor comprises a rotor and a stator; a stator coil is connected to an external power grid for outputting or receiving the electric energy; a rotor coil is connected to the controller after being led out in a conventional manner; the input of the controller is connected with the power grid. The speed-regulation synchronous motor assembling unit is characterized in that the rotor comprises two excitation coils; two rotor coils are arranged at the distance of electrical angle alpha in space; two alternating current exciting voltages are output by the controller to be respectively connected with the two rotor coils so as to form two alternating current exciting currents; the phase difference of the two alternating current exciting currents is (pi-alpha), and the angular frequencies are shown by the following formula: omega f=omega s- omega m (omega s represents power grid angular frequency, and omega m represents the electric angle speed of the rotor; a rotating magnetic field is formed by the two alternating current exciting currents; and the rotating speed of the rotating magnetic field, relative to the rotating speed of the stator, is synchronous speed omega s. The speed-regulation synchronous motor assembling unit provided by the invention has wide speed regulation range, and can be used as a wind power generator, thereby broadening the wind adapting range, abolishing a speed raising gear case and improving the wind energy utilization rate.

Description

technical field [0001] The invention relates to speed-regulating motor technology, especially synchronous motor and its speed-regulating technology. Background technique [0002] Wind energy is renewable, clean and environmentally friendly, and has huge reserves. Wind power generation is one of the main development directions of new energy. In order to adapt to the instability of wind speed, traditional wind turbines use asynchronous motors, and the head is also equipped with a speed-up gearbox to increase the speed of the low-speed rotating blades to the speed of the asynchronous motor. The asynchronous generator needs to absorb reactive power from the grid, which will increase the grid loss and may cause grid stability problems; the speed-up gearbox is high in cost and low in efficiency, which increases the weight of the machine head and limits the height of the tower; and is suitable for wind The range is narrow, the wind speed for power generation is 5-25m / s, and the wi...

AI Technical Summary

Problems solved by technology

The asynchronous generator needs to absorb reactive power from the grid, which will increase the grid loss and may cause grid stability problems; the speed-up gearbox is high in cost and low in efficiency, which increases the weight of the machine head and limits the height of the tower; and is suitable for wind The range is narrow, the wind speed of power generation is 5-25m / s, and the wind speed of the grid is 3-30m / s

[0003] The AC-DC-AC frequency conversion speed regulation on the stator side of the traditional synchronous motor has high cost and large loss

[0004] Asynchronous motors are divided into frequency conversion speed regulation and double-fed speed regulation. Frequency conversion speed regulation is the same as stator-side speed regulation of synchronous motors. It has high cost and large loss, and is not suitable for large-scale motor applications; double-fed speed regulation motors work in asynchronous state and are affected by asynchronous Torque M-slip s characteristic constraints, limited speed range, still can not get rid of the speed-up gearbox of the wind turbine

[0005] Chinese patent application ZL200810054781.7 (invention name: a single-fed synchronous wind power generating set), discloses a speed regulation scheme of a wind power generating set. Three-phase, the rotor winding is also three-phase, the stator winding is p-pole, the rotor winding is also p-pole, the structure is complicated, it is not suitable for manufacturing; there are more rotor windings, so the inverter output circuit is also more

In the scheme of this patent application, the double-fed speed controller is used for the excitation control of the speed-regulated synchronous machine, but the double-fed controller can only make ω f ≈ω s -ω m , there is no guarantee that ω f = ω s -ω m , so the scheme of this patent application is difficult to implement in practice

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