Inverters for brushless DC motors can be divided into two basic topologies: voltage source inverters and current source inverters. Controllers can be further classified according to the solid-state switches used and based on different control strategies. The most common and widely used VSI topology is the three-phase, six-state and six-switch drive. Generally, simpler controllers only need commutation control and current control functions.

　　At present, under the premise of taking into account the performance, reducing the cost as much as possible has become another hot issue in BLDCM research. In order to reduce the cost of the driver, two methods can be used, namely, changing the circuit topology and changing the control strategy. In the cost of electronic drives, solid-state power switches, inductors, and large electrolytic capacitors are the main components. Therefore, in terms of circuit topology, try to use fewer power switches, sensors, and related circuits to minimize the cost of the inverter.

　　This article is taken from ------"Permanent Magnet Brushless DC Motor Technology"