Rotating speed tracking method based on permanent magnet synchronous motor open loop vector

Abstract

The invention discloses a rotating speed tracking method based on a permanent magnet synchronous motor open loop vector. The method comprises the following steps of 1, using a mixing model flux linkage observer to estimate a current motor rotor flux linkage angle, then carrying out differential and estimating a current motor rotating speed; 2, carrying out coordinate conversion on a stator currentvector and acquiring an excitation current id and a torque current iq; 3, taking the id and zero as input, carrying out operation by an excitation current regulator and acquiring an excitation voltage ud; taking the iq and the zero as the input, through a torque current regulator, acquiring a torque voltage uq; 4, carrying out vector synthesis on the ud and the uq, carrying out space vector modulation wave calculation, and comparing with a triangular wave to generate a driving control signal so as to drive a permanent magnet synchronous motor; and 5, repeating the steps1, 2, 3 and 4 till thattwo current vectors are stabilized near the zero and maintain for a short time period, considering the rotating speed estimated at this moment to be a current motor rotation speed, taking the currentrotation speed as a start rotation speed and smoothly switching to synchronization motor speed control.

Description

technical field [0001] The invention belongs to the technical field of speed regulation of permanent magnet synchronous motors, in particular to a speed tracking method based on open-loop vectors of permanent magnet synchronous motors. Background technique [0002] In high-performance permanent magnet co-motor vector control systems, closed-loop speed control is usually used. The speed is generally obtained by the encoder and estimated according to the mathematical model. However, because the encoder affects the simplicity and reliability of the permanent magnet synchronous motor speed control system in terms of installation, maintenance, and cost, people have proposed an open-loop vector speed closed-loop Control plan. The core problem is the estimation of rotor speed information. There are many algorithms for estimating the speed of permanent magnet synchronous motors. For example, direct calculation, observer, self-adaptation, artificial intelligence and other means are...

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Problems solved by technology

Although the physical concept of this idea is clear and clear, it is difficult to implement. The scheme has the following problems: 1. There is no DC bus current detection in the general inverter device, and the DC bus current is the smallest and the DC bus capacitance changes within a short period of time. Difficult to judge; 2. If there is a large gap between the current searched stator magnetic field frequency and the actual motor speed, especially when the stator magnetic field frequency is in the opposite direction to the motor's actual speed, the search time of the speed search device will be longer

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