Speed Coordination of Multiple PMSM Drives by a Distributed Nonsmooth Bipartite Consensus Protocol

ABSTRACT

Aiming at the coordinated speed regulation in multiple permanent magnet synchronous motors (multi‐PMSMs) under signed directed communication relationships, this paper presents a speed coordination strategy using a distributed nonsmooth bipartite consensus protocol (DNBCP). The mathematical modeling of multi‐PMSMs is first established. Next, the multi‐PMSM drive system is described within a multi‐agent system (MAS) framework comprising one virtual leader PMSM (VL‐PMSM) and several follower PMSMs. Then, an integral sliding‐mode speed regulator incorporating an improved logarithmic reaching law with variable power is developed for the VL‐PMSM. This improves the speed‐tracking response and provides a stable reference trajectory for the follower PMSMs. A DNBCP with a nonsmooth function is developed for the speed loops of follower PMSMs, and the ‐axis reference current is generated accordingly. Finally, a simulation platform consisting of four surface‐mounted PMSMs is set up. The control scheme is examined further under step load disturbances and sinusoidal load disturbances with parameter perturbations. The results show that the positive and negative follower subgroups track the reference speed and its sign‐reversed value, respectively. Compared to other methods, the proposed approach minimizes transient overshoot and speed deviation induced by disturbances. It also maintains bounded coordination errors under compound uncertainty.