Current control method of IPMSM in constant power region for HEV

2021

Energies

Self Cite

This paper proposes a compensation method for interpolation error of the maximum power control of a PMSM control system that generates current commands through a look-up table. A torque control system using a look-up table created through experiments has superior characteristics, such as control stability and torque accuracy, compared to a system that executes torque control via a linear controller based on modeling. However, it is impossible to generate information on all the currents for the output torque in the table. Therefore, because the data stored in the look-up table have a discrete characteristic, they are linearly interpolated to generate a current command for the torque command. However, the PMSM current trajectory is generally elliptical, which causes an error owing to linear interpolation, reducing the maximum output power. In particular, when the table data are insufficient, such as in the high-speed operation range, the reduced maximum output cannot be ignored. This paper proposes a compensation method for the interpolation error using two feedforward compensators and a PI controller, which was verified through experiments.

Section: Experiments Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Compensation of Interpolation Error for Look-Up Table-Based PMSM Control Method in Maximum Power Control

Kim¹,

2021

Energies

Self Cite

“…where P n is pole-pair and ∆T * e_int is increased torque output from compensated current. The compensation value of the q-axis current can be obtained by substituting the d-axis current value from Equation (8) into Equation (4).…”

Section: Two-dimensional Interpolation Error In Look-up Table Based Pmentioning

confidence: 99%

“…Therefore, it is impossible to store the appropriate current data for the entire driving region. To solve this problem, two-dimensional interpolation has been used to properly interpolate input data that have not been previously stored in the memory [7][8][9]. Two-dimensional interpolation produces the linear outputs of two continuous input parameters that are not defined at the specific torque and flux points of the look-up table address from the discreet look-up table data.…”

Section: Introductionmentioning

confidence: 99%

Feedforward Interpolation Error Compensation Method for Field Weakening Operation Region of PMSM Drive

2019

Electronics

This study proposes a field weakening control method with interpolation error compensation of the look-up table based permanent-magnet synchronous machine (PMSM) method. The look-up table (LUT) based control method has robust control characteristics compared to other control methods that use linear controllers for current reference generation. However, it is impossible to store all current references under all circumstances for torque commands. General LUT based control methods use two input parameters. In order to mitigate the effect of discretely stored data, two-dimensional interpolation is used to linearly interpolate values between discontinuous data. However, because the current trajectories of PMSMs are generally ellipsoidal, an error occurs between the linearly interpolated and controllable current references. This study proposes a method to compensate for this interpolation error using a feedforward controller for rapid compensation. The improvement using the proposed method is verified by experiment and simulation.

“…This LUT is established experimentally under extreme conditions in order to consider the inductance saturation or resistance variation, and thus the target drive has a steady torque generation against variations in the guaranteed operation range [1]. A general LUT-based PMSM drive uses a two-dimensional look-up Table (2D-LUT), speed-torque [2][3][4], or flux-torque [1,[5][6][7][8] for reference. Figure 1 shows these control methods.…”

Section: Introductionmentioning

confidence: 99%

Low Cost Simple Look-Up Table-Based PMSM Drive Considering DC-Link Voltage Variation

Kim

2020

Energies

Self Cite

This paper proposes a permanent magnet synchronous machine (PMSM) table-based torque control method considering a variable DC-link voltage that can be used in a low cost DSP. The current reference generation based on two-dimensional look-up table (2D-LUT) is widely used for PMSM drives used in industrial applications because of its torque control performance and operation stability. In general, a 2D-LUT is established based on the flux and torque to overcome the variation in DC-link voltage. However, this method requires a flux estimator for estimating the instantaneous flux, which is defined as a division of the operating speed used to obtain the flux data. Therefore, to obtain the operating flux, a variable division calculation or complex controller is used, which can be difficult to process through a low cost digital signal processor. In this paper, a novel look-up table-based control method that uses the newly established speed-torque 2D-LUT is proposed. This 2D-LUT inherently implements data on the d-/q-axis currents throughout the operating regions, not only the speed and torque, but also the DC-link voltage variation. The proposed method was verified through an experiment on the torque control a variation in the DC-link voltage.