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付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23903号 / 工博第4990号 / 新制||工||1779(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 雨宮 尚之, 准教授 掛谷 一弘, 講師 美舩 健, 教授 松尾 哲司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This thesis focuses on utilizing the persistent voltage vector injections by finite control set model predictive control (FCSMPC) to enable simultaneous estimations of both position and parameters in order to realize robust sensorless interior permanent magnet synchronous machine (IPMSM) drives valid at the entire operating region including no-load standstill without any additional signal injection and switchover. The system (here, IPMSM) needs to meet certain observability conditions to identify the parameters and position. Moreover, each combination of the parameters and/or position involves different observability requirements which cannot be accomplished at every operating point. In particular, meeting the observability for parameters and position at no-load standstill is more challenging. This is overcome by generating persistent excitation in the system with high-frequency signal injection. The FCSMPC scheme inherently features the persistent excitation with voltage vector injection and hence no additional signal injection is required. Moreover, the persistent excitation always exists for FCSMPC except at the standstill where the control applies the null vectors when the reference currents are zero. However, introducing a small negative d axis current at the standstill would be sufficient to overcome this situation.The parameter estimations are investigated at first in this thesis. The observability is analyzed for the combinations of two, three and four parameters and experimentally validated by online identification based on recursive least square (RLS) based adaptive observer. The worst case operating points concerning observability are identified and experimentally proved that the online identification of all the parameter combinations could be accomplished with persistent excitation by FCMPC. Moreover, the effect of estimation error in one parameter on the other known as parameter coupling is reduced with the proposed decoupling technique. The persistent voltage vector injections by FCSMPC help to meet the observability conditions for estimating the position, especially at low speeds. However, the arbitrary nature of the switching ripples and absence of PWM modulator void the possibility of applying the standard demodulation based techniques for FCSMPC. Consequently, a nonlinear optimization based observer is proposed to estimate both the position and speed, and experimentally validated from standstill to maximum speed. Furthermore, a compensator is also proposed that prevents converging to saddle and symmetrical ( ambiguity) solutions. The robustness analysis of the proposed nonlinear optimization based observer shows that estimating the position without co-estimating the speed is more robust and the main influencing parameters on the accuracy of the position estimation are d and q inductances. Subsequently, the proposed nonlinear optimization based observer is extended to simultaneously estimate the position, d and q inductances. The experimental results show the substantial improvements in response time, and reduction in both steady and transient state position errors. In summary, this thesis presents the significance of persistent voltage vector injections in estimating both parameter and position, and also shows that nonlinear optimization based technique is an ideal candidate for robust sensorless FCSMPC. / Thesis / Doctor of Philosophy (PhD)

Switched Reluctance Machines (SRMs) are receiving significant attention from industries in the last decade. They are extremely inexpensive, reliable and weigh less than other machines of comparable power outputs. Although the design principles of the machine are available as a concatenation of many different sources, the need for a unified, step-by-step design procedure from first principles of electromagnetics is an absolute requirement. This dissertation discusses a procedure that can be applied by engineers with a basic background in electromagnetics. Subsequent to the design of the machine, existing finite element software can do the analysis of the machine. However, this is a laborious process and the need for an analytical method is preferable to verify the design procedure before the final verification by finite elements. The analytical procedure as well as a procedure to calculate iron losses is also developed in this dissertation. A prototype machine has been developed as an example of the design process and an existing prototype is analyzed to verify the analysis procedure. The similarities between the SRM and the Permanent Magnet Brushless DC Machine (PMDBC) beg the consideration of the development of a converter that can be used to drive either machine. One such converter has been developed in this dissertation. The design of the drive for both the machines is seen to be very similar. As a consequence, a universal controller that can be used to operate both machines has been developed and implemented with a DSP. Simulations and experimental correlation for both drives have been presented. / Ph. D.

No / Two new complexes, [Fe3(μ3-O)(inicH)6(H2O)3][Gd(NO3)6]·(NO3)4·nH2O (1) and [Fe3(μ3-O)(inicH)6(H2O)3][Dy(NO3)5 (H2O)]·(NO3)5·n(H2O) (2) with two isolated complex moieties, were generated when isonicotinic acid was treated with iron(III) nitrate and the corresponding lanthanide(III) nitrate in water. The structures were determined by single-crystal X-ray diffraction studies. In these compounds, the anionic lanthanide complexes are encapsulated by trinuclear [Fe3(μ3-O)(inicH)6(H2O)3]7+ cationic cluster units, which is facilitated by hydrogen-bonding interactions. Investigation of the magnetic properties reveals that 2 shows slow relaxation of magnetization at low magnetic field (Hdc = 1.0 kOe), with an energy barrier of 23 K originating from a single [Dy(NO3)5(H2O)]2– anion. / Errata: 2014(25): 4228 (http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ejic.201402684)

No / This article corrects http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ejic.201402114. 2014(19): 3065-3071.

Permanent magnet brushless dc (PMBDC) and synchronous machines (PMSM) drives are favored in variable speed applications for their high efficiency operation. Energy efficiency improvement in such motor drives is of interest in recent times because of rising cost of energy. Accordingly, two current control options for improving efficiency of these drives are taken for study and they are; (i) injecting sinusoidal and non-sinusoidal currents in PMBDC machines and (ii) lowering switching frequency of inverter driving the PMSM but without having significant low ordered sidebands of currents. Both these methods are applicable to existing types of permanent magnet motors and hence do not upset their existing optimized designs. / Ph. D.