A Design Method of Discrete Domain Current Regulator

Abstract

The invention discloses a discrete domain current regulator design method, comprising the steps of: according to a discrete domain mathematics model in an AC motor current inner ring, designing a discrete domain regulator G<e>cc(Z) of a synchronous rotating coordinate system current inner ring including an adjustable parameter k; and according to the adjustable parameter k of the discrete domain regulator G<e>cc(Z), employing non-overshoot as an optimization target, performing calculation based on a formula to obtain an optimization value K<z>op, and substituting K<z>op into G<e>cc(Z) to obtain an optimized discrete domain regulator G<e>ccop(Z). The discrete domain current regulator design method eliminates the cross coupling of d axis and q axis control rings, realizes complete independent design which can not be realized by a traditional linear PI regulator, does not need a feedforward decoupling link, and avoids errors caused by discretization after designing a regulator in a continuous domain; meanwhile, the method considers digital control system delay influence, provides an accurate design formula of a controller adjustable parameter k, realizes current ring step response non-overshoot, does not need repeated debugging, and has sound versatility and practicality.

Description

technical field [0001] The invention relates to the field of speed regulation and control of high-performance AC motors, in particular to a design method of a discrete domain current regulator. Background technique [0002] With the improvement of the performance and control accuracy requirements of the speed control system in modern industrial applications, vector control technology is widely used in occasions that require high-performance control of AC motors. The vector control decomposes the stator current into the excitation component and the torque component in the synchronous rotating coordinate system of the rotor field orientation, and then uses the PI regulator to realize the independent adjustment of the two, and finally uses pulse modulation such as space vector pulse width modulation (SVPWM) The algorithm synthesizes the reference voltage to achieve high-performance control of the AC motor. However, when the electrical quantity is transformed into a synchronous...

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Problems solved by technology

However, these methods do not give a specific design method for the adjustable parameter k. In practical applications, it still needs to be adjusted based on experience and trial and error.

At present, there is no better method that can simultaneously satisfy: 1) Eliminate the cross-coupling of the two control loops of the d and q axes; 2) Design the regulator directly in the discrete domain to avoid discretization errors; 3) Consider the influence of the delay of the digital control system ; 4) The design formula of the accurate controller adjustable parameter k is given

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