Direct adaptive current control a universal current control scheme for electrical machines

Abstract

This paper presents a direct, adaptive and parameter-free current control scheme that is independent of the motor type and doesn't need any machine parameters. A given setpoint can be reached accurately within one switching cycle.

Measurement of Two-Level Inverter Induced Current Slopes at High Switching Frequencies for Control and Identification Algorithms of Electrical Machines

“…Indirect current slope identification means, that the current slopes are calculated in the signal-processing hardware after the analog digital conversion. This is done by evaluating the measured absolute current values for example with least-squares estimators [2], linear regression or current deviation principles [1]. The absolute current measurement values can be determined with different physical principles.…”

“…Assuming a homogenous field of the conductor, the flux inside the planar Rogowski coil can be determined with equation (2).…”

“…Precise and fast identification of the inverter induced current slopes is mandatory for many sensorless or selfsensing control schemes [1], adaptive control algorithms [2], online parameter identification [3], rotor-temperature identification [4] or inner fault detection [5] of electrical machines. Higher switching frequencies of actual silicon-carbide semiconductors are desired to reduce weight and space and increase power density compared to the regular IGBT inverters.…”

Resource optimal FPGA implementation of a Least-Squares-Estimator for fast and robust online measurement of current slope and absolute value

“…In modern control methods for power electronics and electrical machines, the knowledge of the current slope (or derivative) of each switching state of the used inverter is a very important measurement value. It can be used for online machine parameter identification [1], modern adaptive control schemes [2,3], condition monitoring and encoderless control [4,5] to name just a few examples. The shape of those PWM-excited current curves in these applications can mostly be assumed to be made up of straight line segments and each switching state of the inverter produces its own current slope (see figure 1).…”

Easy current slope detection for low cost implementation of the direct adaptive current control for DC-DC-converters

“…In [3], [4] the Direct Adaptive Current Control (DACC) scheme has first been presented for the control of a DC/DCconverter and for single phase applications such as the armature current of a DC machine [5]. Later it was adapted for the current control of magnetic isotropic 3-phase synchronous machines (with L d = L q ) [6], magnetic anisotropic synchronous machines (L d = L q ) [7] and even for 3-phase induction motors [8]. It shows excellent control quality and high dynamics.…”