Brushless DC motor speed control has these requirements

The production process of brushless DC motors has certain requirements for speed control performance. To sum up, the speed control requirements for the speed control system have the following three aspects: 1. Speed control, within a certain range of high and low speeds, divided into The speed is adjusted by gears (steps) or smoothly (stepless); 2. Stable speed, stable operation at the required speed with a certain accuracy, and no excessive speed fluctuations under various interferences to ensure the product Quality; 3. Equipment with acceleration/deceleration, frequent starting, and braking requires acceleration and deceleration as fast as possible to improve productivity, and machinery that is not suitable for severe speed changes requires starting and braking as smooth as possible.

In addition, for the first two requirements, two speed control indicators are defined as "speed control range" and "static difference rate". The mechanical requirement is that the brushless DC motor provides an AC speed range of the ratio of high speed to low speed. The motor has high and low speed at rated load. For machinery with very light load, it can achieve high and low speed at load. Static difference rate: When the system is running at a certain speed, the ratio of the corresponding speed when the brushless DC motor load increases from the ideal no-load to the rated value and the ideal no-load speed is called the static difference rate. The static difference rate is used to measure the speed stability of the speed control system when the load changes. It is related to the hardness of the mechanical characteristics. The harder the characteristic, the smaller the static difference rate, and the higher the stability of the speed.