Background. Servo electric drives are used in various motion control systems. One of the types of electric machines used in servo electric drives is brushless alternating current motor. For its vector control it is necessary to implement coordinate transformations depending on the angular position of its rotor. In this case, in the orthogonal system of axes rotating together with the rotor, the target value of the magnitude of the electromagnetic torque is set and in the stationary three-phase system of axes, the power converter is controlled. To perform coordinate transformations, a high intensity of signal sampling and timely execution of calculations in relation to the angular rotor position are required. It limits the rotation speed that can be achieved by the electric drive, including when processing dynamic motion processes. Thus, there is a question of increasing computing resources by distributing control tasks between two microprocessor devices in the electric drive connected via a high-speed interface.
Materials and methods. During the development of a servo electric drive with vector control of a brushless alternating current motor, the authors have used the methods of algorithmization of control processes, methods of the automation control theory, as well as methods of development and debugging software. When developing the software for the electric drive, the technology of model-based programming has been used.
Results. The article provides a detailed description of the development of a servo electric drive with vector control of a brushless alternating current motor, in which the control tasks are distributed between the servo controller and the servo driver to increase the available computing resources. It is proposed to use a servo controller to perform tasks related to control the angle of rotation, forming the target value of electromagnetic torque in the rotating axis system and calculating the target values of phase currents in the stationary axis system. Phase current generation during power converter control is performed using a servo driver in stationary system of axis. To achieve this, the phase current target values in the stationary axis system are transmitted from the servo controller to the servo driver in the form of analog signals. It is shown that the coordination of the calculations is achieved due to the speed of this analog interface and the implementation of the servo driver in the stationary axis system.
Conclusions. The applied technical solutions make it possible to allocate the computing resource of the servo driver to increase the intensity of input and processing of signals used in vector control of a brushless alternating current motor. The proposed distribution of control tasks between two devices connected as parts of an electric drive by a high-speed interface, considering the signals and data used by them, contributes to improvement of characteristics of electric drive, but requires their coordinated implementation. The servo driver is designed as a full-fledged device that can be used as a part of a motion control system in a quantity depending on the number of its axes. The developed servo controller software can serve as a prototype for a multi-coordinate motion control system.