Permanent-magnet DC brushless variable speed constant-pressure wind power generator and its voltage stabilization method

Abstract

The invention relates to a permanent magnetism dc brushless varying speed pressure-sustaining wind-driven generator and its anti-hunt means. The generator is derived by the varying speed wind-orbicular and sends the pressure-sustaining dc power which has been outputted to the power net after frequency-transferring; when the motor achieves the mix working rotate speed, the armature winding leak per-unit quantity against X* equals the rate of the difference of the motor mix rotate speed and the min rotate speed and the min working rotate speed with the range 0.1-1.7.

Description

Technical field: [0001] The invention relates to a generator, in particular to a permanent magnet DC brushless variable speed constant pressure wind power generator driven by a variable speed wind wheel and a voltage stabilizing method thereof. Background technique: [0002] The grid-connected wind turbine converts the mechanical energy captured by the wind wheel into electrical energy and transmits it to the constant voltage and constant frequency grid. When high-power power electronics technology is not mature enough, it is very difficult to change the frequency and voltage of wind power generated by generators. In order to directly transmit wind power to the grid, only AC asynchronous generators or AC synchronous generators with the same frequency as the grid are selected. The asynchronous generator can only run within the speed difference range of 1% to 4% above the synchronous speed, and the synchronous generator can only run at the synchronous speed. In order to make...

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Problems solved by technology

The advantage of these two motors is that they can be directly connected to the grid without inverter, but there are many shortcomings: 1. The power-speed characteristics of the motor are relatively hard, and it is difficult to match the output characteristic curve of the wind wheel well, and it is also difficult to improve the capture rate. Wind energy efficiency to absorb wind energy to the maximum; 2. It is easy to cause impact on the unit and the grid when connected to the grid; 3. Due to the instability of wind speed, it is easy to impact on the gearbox and damage the gearbox, resulting in high maintenance costs; 4. Generators are often in the state of shutdown, low-speed power generation, and high-speed power generation. The control is complex and prone to failure; Not large and can only be driven by constant speed rotors which are less efficient at capturing wind energy on average

The doubly-fed asynchronous generator represented by VCS technology can convert the wind energy captured by the variable-speed wind rotor into electric energy as much as possible, increase the power generation, maintain low-noise operation, and reduce the load on the gearbox. Slip ring, complex structure, it is difficult to save direct drive operation without gearbox

The disadvantages of this method are: 1. Due to the need to add sampling control circuits, voltage regulating actuators, executive motors and other equipment, the control system and mechanical structure are relatively complicated, which greatly increases the production cost; 2. Due to its complex regulation It is difficult to apply on large-scale generators (such as MW-level wind turbines) (because if large-scale generators use this method to regulate voltage, the pressure-regulating actuator will be very large, the structure is extremely heavy, and it is difficult to realize)

Therefore, the voltage stabilizing methods disclosed in these patents all have the above-mentioned many deficiencies.

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