High-Frequency Issues Using Rotating Voltage Injections Intended For Position Self-Sensing

Abstract

Abstract-The rotor position is required in many control schemes in electrical drives. Replacing position sensors by machine self-sensing estimators increases reliability and reduces cost. Solutions based on tracking magnetic anisotropies through the monitoring of the incremental inductance variations are efficient at low-speed and standstill operations. This inductance can be estimated by measuring the response to the injection of high-frequency signals. In general however, the selection of the optimal frequency is not addressed thoroughly. In this paper, we propose discrete-time operations based on a rotating voltage injection at frequencies up to one third of the sampling frequency used by the digital controller. The impact on the rotation-drive, the computational requirement, the robustness and the effect of the resistance on the position estimation are analyzed regarding the signal frequency.Index Terms-AC motor drives, Sensorless control, Highfrequency signal-injection, Permanent-magnet (PM) machine NOMENCLATURE αβ axes of the stationary frame; qd axes of the synchronous frame; xy axes of the anisotropy frame; ϕ x angle of the anisotropy frame with respect to αβ; x denotes a space vector, that can be the current i, the voltage v, the flux ψ or the back-emf e PM ; a denotes an anisotropic parameter, that can be the resistance r or the incremental self-inductance l t ; a + , a -positive and negative parameters, corresponding to a; x(t) continuous-time value; ν s , T s sampling frequency and sampling period: ν s = 1/T s ; x(t [k] ) samples of the value at sampling instants t [k] ; x [k] mean of x(t) between two sampling instants;

Adaline Neural Networks-based sensorless control of five-phase PMSM drives

“…At high speed, both of them work correctly except there is a high windup of the speed at the beginning with the classical PLL for position tracking due to initial state of the PLL at zero speed. It means that at low and very low speeds, a sensorless control based on a classical PLL needs some additional information, usually high frequency signals [6], to operate correctly. Contrary, the speed response obtained with Adaline approach is better at low speed thanks to the capacity of learning shown in Fig.…”

“…That is why the second approach has been studied specially for this operating point. Indeed, a high-frequency injection (sinusoidal or pulse signals) is superimposed to the fundamental frequency signal for rotor position detection thanks to the exploitation of PMSM feature of magnetic saliency [6], [7].…”

Axial Position Estimation of Conical Shaped Motors for Aerospace Traction Applications

“…Over the last decade, sensor-less techniques for electric machine control have become a common and robust [22], way to achieve high levels of reliability, especially where costs need to be reduced and the space allocated to the drive represents a compelling factor [23]. The main sensor-less methods can be categorized as fundamental wave based (i.e.…”

A rotor initial position estimation method for sensorless control of SPMSM

“…Most researches track the saliency of PMSM to estimate the rotor position. To interior permanent magnet synchronous machines (IPMSM), as d-axis inductance is different from q-axis inductance, they belong to salient pole machines, high frequency (HF) signal injection is wildly used in the rotor position estimation [1][2][3][4][5][6]. A sequence of voltage pulses are applied to the stator phases and the measured peak current gives information about the initial rotor position [1].…”

“…Indeed, the application of voltage pulse gives a high torque ripple. A rotating sinusoidal voltage is applied to the stator windings and the initial rotor position is extracted by the second harmonic of the negative-sequence carrier current [2][3][4][5]. However, to surface mounted permanent magnet synchronous machines (SPMSM), as d-axis inductance equals to q-axis inductance, it is difficult to estimate the rotor position by tracking the saliency.…”