RTLinux based speed control system of SPMSM with an online real time simulator

Abstract

Keywords: digital speed control, online real time simulator, RTLinux, SPMSM In this paper we propose the new method to achieve the experimental system with an online simulator using a RTLinux based PC system. This system consists of mainly two functions. One is the simulation part, where a motor mathematical model based on the three phase stationary coordinate is solved using a fourth order Runge-Kutta method in real time. The motor model includes non-linear operation, such as, trigonometric functions, square waves generated by a PWM inverter, dead time, and limiter circuits, so on. The other is the motor control part where conventional PI controllers and de-coupling controllers are programmed. The system is able to realize the motor control in 200 µs period and achieves the online real time simulator simultaneously.The configuration of the experimental system which includes the online real time simulator is shown in Fig. 1. The outputs of the real time simulator can be used for the control, and these variable is also corrected and modified using the real values. All of these functions are implemented in the computer, so it is easy to select the data. The simulation time is about 23 µs and it takes about 33 µs for the control in the system. From the results, it is enough to achieve the online real time simulation and the control at the same time. Figure 2 shows the experimental results of the control performance when the sampling interval of the pulse encoder is expanded. Here, the measured data is obtained by 20 ms period. While the output speed of the simulation is used in every 200 µs to the control instead of the measured value. Figure 2(a) shows the result when the speed is detected as an average values every 20 ms. The result of the step response is not desirable. On the other hand, Fig. 2(b) shows the result when the speed data of the online real time simulator is used for the control every 200 µs. And the simulation results is revised by the measured value only once in a hundred times. To compare these two results, Fig. 2(b) to be the satisfactory result. Fig. 1. Configuration of the proposed systemWe proposed the online real time simulator using RTLinux based PC system and achieve both the speed control system of SPMSM and the real time simulation simultaneously in 200 µs control period. From the experimental results, it is clear that our model is valid and the system parameters are identified correctly. The proposed method is useful of the analysis and control design of the motor drive system and it has the possibility of more precise control and sensorless control. MemberAhmad Ghaderi * Non-memberTeruo Tsuji * MemberAn online real time simulator for a RTLinux based speed control system of SPMSM (Surface Permanent Magnet Synchronous Motors) is proposed. For realization of the online real time simulator, a motor mathematical model based on the three phase stationary coordinate is solved using a fourth order Runge-Kutta algorithm in real time. The Runge-Kutta algorithm is required since the model includ...

Rotor position estimator using non-linear observer of surface permanent magnet synchronous motor

“…They are maintenance free, have high energy density, and attain high performances needed to employ vector control. In addition, sensorless speed controls in AC motors have been proposed in response to reductions in weight, size, and total cost requirements [1][2][3]. In this paper, a position estimator for surface permanent magnet synchronous motors (SPMSMs) at start-up is proposed.…”