A Super-Twisting Sliding-Mode Stator Flux Observer for Sensorless Direct Torque and Flux Control of IPMSM

Abstract

The scheme based on direct torque and flux control (DTFC) as well as active flux is a good choice for the interior permanent magnet synchronous motor (IPMSM) sensorless control. The precision of the stator flux observation is essential for this scheme. However, the performance of traditional observers like pure integrator and the low-pass filter (LPF) is severely deteriorated by disturbances, especially dc offset. Recently, a sliding-mode stator flux observer (SMFO) was proposed to reduce the dc offset in the estimated stator flux. However, it cannot eliminate the dc offset totally and will cause the chattering problem. To solve these problems, a novel super-twisting sliding-mode stator flux observer (STSMFO) is proposed in this paper. Compared with SMFO, STSMFO can reduce the chattering and fully eliminate the dc offset without any amplitude and phase compensation. Then, the precision of the stator flux and rotor position can be greatly improved over a wide speed region. The detailed mathematical analysis has been given for comparing it with another three traditional observers. The numerical simulations and experimental testing with an IPMSM drive platform have been implemented to verify the capability of the proposed sensorless scheme.

Sensorless PMSM Drive Implementation by Introduction of Maximum Efficiency Characteristics in Reference Current Generation

“…The active flux based sensorless control method is applied. The active flux Ψ AF is defined as a hypothetical flux, which multiplied by the instantaneous q-axis current i q produces the measured instantaneous electro-magnetic torque t e [32][33][34][35]. Consequently, the effects which are neglected in the PMSM model are thus considered by employment of Ψ AF .…”

“…Moreover, in this work the ME characteristics are implemented in sensorless control for the first time and presented in Section 4. There the rotor speed and position are determined by nonlinear phase-locked loop (PLL) observer [9,31], whose inputs are calculated by the modified active flux method [32][33][34][35]. It is shown that the drive efficiency can be improved when ME characteristics are used to generate the d-and q-axis current references, which is true for the sensorless control as well as for the control realization with position sensor.…”

Sensorless flux adaption DTFC of an IPMSM based on an active flux‐based MTPA and an adaptive second‐order sliding mode observer

“…As shown in (18), due to the saliency L d ≠ L q of IPMSMs, its reluctance torque can be utilised to maximise the electrical torque with the same stator current. In addition, simple i d = 0 control will reduce the efficiency of IPMSMs.…”

“…Boldea et al [17] describe the concept of active flux and the active flux is always utilised to realise the sensorless control of IPMSM. In [18,19], the active flux is observed by an SMO, and then the rotor position information can be obtained easily. In [20], a high-frequency injection method which makes up for the low signal noise ratio of active flux at low speed is combined with the active flux to realise sensorless control in full speed domain.…”

Switching Sequence Model Predictive Direct Torque Control of IPMSMs for EVs in Switch Open-Circuit Fault-Tolerant Mode

“…The drive system of interior permanent magnet synchronous motors (IPMSMs) [1,2] based on two-level voltage source inverters (2L-VSIs) [3,4] has become one of the mainstream speed control schemes for electric vehicles (EVs) due to advantages, such as high efficiency, excellent speed regulation performance, and high power density. In order to improve the security of EVs, the functional safety of the drive system has gradually become one of the research hotspots.…”