Praca dwumaszynowego napędu z silnikami BLDC w elektromechanicznych stanach przejściowych

The paper describes design and operation of processor-based control system of two-machine driver with BLDC motor. This type of drive may be applied for example to mobile wheel robots, powered wheelchairs etc. Such drives require fast, four-quadrant and reversible controller, which allows for operation in All four quadrants of current-voltage co-ordinate system, making it possible to change over from driving mode to braking mode and to reverse rotational direction smoothly. The operation is directed by processor-based motor speed control system, consisting of standard controller block, measurement block and transistor converter. Transistor converter used here is built on the basis of three-phase inverter bridge structure with a single pair of complementary transistors. This type of structure makes possible simple transition from driving to kraking operation, without any additional switching manoeuvres. Currents and rotational emfs of motors are measured in the speed blocks; those quantities are represented by alternating waveforms. The principal measurement problem is to determine proper sign (negative or positive) of quantities indispensable to correct operation of control algorithms. This is important in drives where rotational direction changes as well as modes of operations (from driving to braking and vice versa for both rotational directions). The paper is supplemented by measured examples of currents and speeds occurring during operation of the drive. It is demonstrated that operations is smooth, without overshootings and jerks.