Tsuyoshi Hanamoto

Wide-Speed-Range Sensorless Vector Control of Synchronous Reluctance Motors Based on Extended Programmable Cascaded Low-Pass Filters

This paper proposes a new sensorless vector control of a synchronous reluctance motor for a wide range of speeds. The estimation of speed and rotor angle is based on extended programmable cascaded low-pass filters (LPFs), which effectively reduce the effects of direct-current (dc) offsets at low speeds. The effect of the number of LPF stages on output dc offset, estimation accuracy, and dynamic performance are determined, and their equations are developed. The determination of the number of LPF stages is based on these developed equations. Because the estimate of the rotor angle near-zero speed is possible, the motor start-up procedure can be done without complexity. The experimental results show that the estimated and the actual rotor angles are in agreement at very low and high speeds. Thus, sensorless vector control can be achieved over a wide range of speeds. In addition, motor start-up in a standstill condition is possible, and the transient response at low and high speeds is acceptable.

Estimation of a Multimass System Using the LWTLS and a Coefficient Diagram for Vibration-Controller Design

Vibration caused by mechanical resonance and time delay caused by signal detection and transmission degrade the control performance of a servo controller for a multimass mechanical system. A precise numerical model that represents resonance characteristics and time delay is necessary to design a desired control system. This paper presents an identification method using the iterative process of the linearized and weighted total least-squares method. The proposed method derives a transfer function without any prior knowledge of resonance characteristics and time delay. The order of the transfer function is determined with a coefficient diagram that shows coefficients of the denominator of the transfer function. Identification results with an experimental setup are shown to demonstrate the performance of the proposed method. A velocity servo controller with vibration-suppression control is designed with the transfer function, and control performance is verified with the experimental setup to validate the transfer function.

An Estimation Method of Rotational Direction and Speed for Free-Running AC Machines Without Speed and Voltage Sensor

This paper presents an estimation method of rotational direction and speed for free running AC machines driven by an inverter without speed and voltage sensor. The method has four estimation modes, and the method utilized only the measured phase current of machines. The amplitude of current during the estimation is suppressed to lower levels such as the exciting current, which is smaller than the rated value. Good performance of this method is confirmed by the experiment.

Sensorless speed control of synchronous reluctance motor using a novel flux estimator based on Recursive Fourier Transformation

This paper proposes a sensorless control of SynRM (synchronous reluctance motor). It can calculate the motor flux from an armature voltage and a current directly. The proposed estimator is able to eliminate both the dc offset and harmonic component of the armature current which cause the estimation error. State observer based Fourier Transformation called RFT (Recursive Fourier Transformation) is effective to estimate the fundamental component of the flux. Also a block pulse approximation is used to convert a continuous time state equation to a difference equation to reduce the calculation time. The validity of the proposed method is shown in the experimental results.

A novel MPPT control method of thermoelectric power generation using state space averaging method

This paper proposes a novel Maximum Power Point ] Tracking (MPPT) control method of thermoelectric power generation. This paper reveals the characteristics and the internal resistance of thermoelectric power module (TM). Analyzing the thermoelectric power generation system with boost chopper by state space averaging method, the output voltage and current of TM are estimated by with only single current sensor. The proposed method can seek without calculating the output power of TM in this proposed method. The basic principle of the proposed MPPT control method is discussed, and then confirmed by digital computer simulation using PSIM. Simulation results demonstrate that the output voltage can track the maximum power point voltage by the proposed MPPT control method. The generated power of the TM is about 0.13W when the j temperature difference is 40 °C. This is well accorded with the, V-P characteristics of the thermoelectric power module.

Digital hardware circuit using FPGA for speed control system of permanent magnet synchronous motor

This paper proposes a novel digital hardware control motor drive system using a FPGA (Field Programmable Gate Array) device. We implement not only a current minor loop but also a speed control loop in the hardware device. We achieve 5 mus period for speed control system of AC motor drive including dq transformation, decoupling control and dead-time compensator, and as a result current ripple and the motor torque ripple is decreased using the dead-time compensator. Experimental results show the validity of the proposed system.

Design of vibration suppression controller for high order resonance system by Mutation-Type Grouping PSO

In this paper, a new design method of vibration suppression controller for multi-mass (especially, 6-mass) resonance systems is proposed. The proposed method is possible to suppress the mechanical vibrations of all modes. The controller consists of a modified-PI-PD controller for speed loop and a PI controller for current minor loop. The seven controller gains are determined by Coefficient Diagram Method (CDM). And then, we propose Mutation-Type Grouping Particle Swarm Optimization (PSO) to design a Coefficient Diagram of the CDM. Comparing with the conventional design algorithm, the proposed technique is able to shorten the time of the controller design to a large extent and to obtain accurate results. Finally, we confirmed the effectiveness of the proposal method by the computer simulations.

FRIT based optimized PI tuning for DC link voltage control of grid connected solar PV system

The grid connected photovoltaic (PV) system have been modeled and simulated using control algorithm with dedicated PI control for dc link voltage regulation. Generally, the PI controller used for the system is tuned using trial and error method but this method is having manual limitation for the tuning of controller so as to obtain the desired response like as regulating dc link voltage to reference value. Fictitious reference iterative tuning (FRIT) method using particle swarm optimization (PSO) helps to generate optimized gains for PI controller which can results in the improved response in terms of response time and overshoot. In this paper, PSO-FRIT based optimized tuning of controller is proposed for the application in LCL filter interfaced grid connected PV system. The current controlled dc-ac power converter has been used for grid connected PV system. Active power reference current for pulse width modulated (PWM) converter is been generated using power balance theory (PBT). The idea of the FRIT based optimized tuning of PI controller is implemented by using the input data and output data from the system obtained using the trial and error method based controller gains. The power quality of the system configuration have been maintained as according to the IEEE-519 standards.

Application of fictitious reference iterative tuning to vibration suppression controller for 2-inertia resonance system

In this paper, we propose an off-line tuning method of the vibration suppression controller gains for 2-inertia system using Fictitious Reference Iterative Tuning (FRIT). FRIT is one of data-driven design methods using only one-shot experimental input-output data without model parameters of the controlled object. We use the modified-IPD speed controller which consists of the 2-degree of freedom PID control, considering response speed, and in addition, we use the first lag element in order to increase degree of freedom of the control design. Then, we consider the current loop for the high speed torque control. In this paper, a PI controller is used for the current control. Here, in this paper, we use the particle swarm optimization as the optimization searching method, and the performance index is the IAE. So, we confirmed the effectiveness of the proposed method which used only one-shot experiment result by experimental setup.

Novel Modulation Method for Multidirectional Matrix Converter

This study presents a new modulation method for multidirectional matrix converter (MDMC), based on the direct duty ratio pulse width modulation (DDPWM). In this study, a new structure of MDMC has been proposed to control the power flow direction through the stand-alone battery based system and hybrid vehicle. The modulation method acts based on the average voltage over one switching period concept. Therefore, in order to determine the duty ratio for each switch, the instantaneous input voltages are captured and compared with triangular waveform continuously. By selecting the proper switching pattern and changing the slope of the carriers, the sinusoidal input current can be synthesized with high power factor and desired output voltage. The proposed system increases the discharging time of the battery by injecting the power to the system from the generator and battery at the same time. Thus, it makes the battery life longer and saves more energy. This paper also derived necessary equation for proposed modulation method as well as detail of analysis and modulation algorithm. The theoretical and modulation concepts presented have been verified in MATLAB simulation.