Direct current control-a new current regulation principle

Abstract

In this paper, two novel methods for current regulation are proposed. Both methods follow the synchronized on-off principle. In the classical approach, transistors are switched depending on the sign of the current error, which in turn is sampled at equal time intervals. In the first method, the current vector at the end of the interval is predicted for two possible cases when either the active voltage vector pointing toward current error or the zero voltage vector is applied. The one producing the smaller current error at the end of the sampling interval is chosen, thus obtaining drastic reduction of the switching frequency. In the second method, the best fitting active voltage vector succeeds the zero vector during the same time interval. A simple algorithm is used to calculate the duty cycle thus gaining the smallest possible current error. The method is compared with the CRPWM. Both methods were simulated and tested on a laboratory model with passive load. In the last part of the paper, the behavior of the second method is tested for erroneously estimated load parameters. The two methods show very small degradation of performance even when a rather high parameter error is introduced.

Current Dynamically Predicting Control of PMSM Targeting the Current Vectors

“…The performance requirement of stator current control is higher for this control strategy, since the current vector is the key to the driving or reposition torque. Currently, the studies above used the method of DCC short for Direct Current Control in [18], which controls the current from the PMSM model in α-β frame, but omitting the effects of speed and the dynamic responses from current vector view. The comparison simulation of the proposed method and the DCC will be done as follow, which will use the method of "constant frequency control" that the switching frequency of current vector is a constant written as f const .…”

Permanent Magnet Synchronous Machine Hybrid Torque Control

“…There are a few papers reporting control schemes applying two converter configurations by computing occurrence [18]- [21]. For example, [22] and [23] present different control schemes with the particularity of using two switching states during a fixed period. Reference [22] presents a scheme for the current control of a passive load: the application times of the two switching states are computed to minimize the norm of the current error vector.…”

“…For example, [22] and [23] present different control schemes with the particularity of using two switching states during a fixed period. Reference [22] presents a scheme for the current control of a passive load: the application times of the two switching states are computed to minimize the norm of the current error vector. This vector cannot be exactly zero.…”

Comparative study of two Predictive Current Controls for a Permanent Magnet Synchronous Machine drive

“…The first one, introduced in [1][2][3][4][5], consists in predicting the future value of the load currents for all the voltage vectors the inverter can generate. Then the inverter configuration which minimizes a cost function is selected.…”