Excitation-varied synchronous motor MTPA (Maximum Torque Per Ampere) control method based on fitting of binary quadratic function

Abstract

The invention relates to an excitation-varied synchronous motor MTPA control method based on fitting of a binary quadratic function, and provides a method for carrying out rectangular axis current function fitting by the binary quadratic function aiming at a rectangular axis current calculating module in a control structure graph (3), and the method comprises the following steps of: respectively fitting the rectangular axis current functions into the binary quadratic functions about Te and psi f, and finally finishing controlling of maximum torque per ampere of the excitation-varied synchronous motor. The excitation-varied synchronous motor MTPA control method based on fitting of the binary quadratic function has the following beneficial effects: (1), the problem that the rectangular axis current function is difficultly acquired in the MTPA controlling of the excitation-varied synchronous motor is solved by carrying out rectangular axis current function fitting through a fitting method of the binary quadratic function; and (2), the method of the binary quadratic function in the method adopted by the invention is simple and effective, and compared with the other two-dimensional look-up table methods, the method has the superiorities of good fitting degree and small occupied memory.

Description

technical field [0001] The invention relates to a method for controlling the maximum torque-to-current ratio of a variable excitation synchronous motor, which is a method for controlling the maximum torque-to-current ratio (MTPA) of a synchronous motor with a changing excitation current using a multi-line (binary quadratic) fitting method The method belongs to the technical field of AC motor transmission. Background technique [0002] Starting / generating integration is an important development direction of future aviation AC power system. At present, most aircraft AC power systems in my country use three-stage brushless synchronous motors (see figure 1 ) as a generator, this type of generator does not have the function of starting an aeroengine, and the engine is started by an independent starter. Such an engine-power supply system includes two sets of motors, which makes the volume and weight large, and the system is complex and the reliability is reduced. If on the basi...

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Problems solved by technology

However, the motor is mainly designed to meet the power generation function, and there are the following problems in the motoring state: 1) In the static and low-speed state, the output voltage of the exciter is low, and the excitation current of the main generator is small, which seriously affects the load of the main generator Starting ability; 2) As the motor speed increases, the output voltage of the exciter gradually increases, and the excitation current of the main generator also gradually increases, that is, the excitation current of the main generator is always changing during the motor starting process

[0010] For formula (3), the function f 1 and f 2 The exact analytical form of is more difficult to determine and cannot be fitted by simple quadratic or cubic polynomials

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