High frequency injection-based stator flux linkage and torque estimation for DB-DTFC implementation on IPMSMs considering cross-saturation effects

Abstract

Deadbeat-direct torque and flux control (DB-DTFC) has demonstrated several technical advantages over classical hysteresis DTC and PI regulator based direct torque control (DTC) methods. These include fast torque control, low ripple, easily integrated dynamic loss minimization control, and one control law that uses the inherent Volt-sec. source properties of power electronics to enable operation over all operating conditions including voltage limits. DB-DTFC uses the fundamental machine model to form the inverse solution for Volt-sec selection at each switching period. Therefore, DB-DTFC is a model-based discrete time controller that relies on accurate machine parameter estimation to provide accurate dynamic torque control. In this paper, a new method for high frequency injection-based real-time self-and mutual inductance estimation is proposed and evaluated in both simulations and experiments. In this new method, the estimated inductances including cross-coupling inductance due to cross-saturation are then used to estimate the stator resistance and permanent magnet flux linkage. The stator flux linkage observer using the identified machine parameters, yields improved stator flux linkage estimates that enable precise torque calculation. Experimental evaluation of the HFI-based flux estimates on torque estimation and control accuracy is performed at an IPMSM drive test bench with torque transducer mounted.

Adaptive controller with an improved high‐frequency injection technique for sensorless synchronous reluctance drive systems

“…Moreover, a phase‐locked loop was employed to estimate the rotor position angle, which was based a saliency model. Lorenz and co‐workers [24–27] proposed a high‐frequency signal injection method for a zero to low‐speed operating range. However, this method also considered that the d ‐axis inductance and the q ‐axis inductance were independent and neglected the d – q coupling inductance.…”

Improved position offset based parameter determination of permanent magnet synchronous machines under different load conditions

“…Electrical parameters of permanent magnet synchronous machines (PMSMs) are usually needed in industrial drives such as maximum torque per ampere (MTPA) control, flux weakening (FW) control [1–3], sensorless control [4–10], condition monitoring [9, 11] and derivation of constants of proportional–integral (PI) regulators [12, 13]. Therefore, in reality, it is of significant importance that the determination of the real parameter model of PMSM should be conducted prior to the design of control systems.…”

Predictive current control and online parameter identification of interior permanent magnet synchronous machines

“…The permanent magnet flux linkage and stator resistance is identified by a RLS algorithm, the current depending flux linkages by a Gopinath observer structure. Due to the necessary Fourier transformation of the sinusoidal test signal, the differential inductances can identified only after a full cycle of the test signal for which 500 Hz were used [12]. Self commissioning methods avoid these problems by applying the test signals at standstill or startup of the control.…”