Nelinearno upravljanje s unutarnjim modelom za pogon s prekidačkim reluktantnim motorom bez oscilacija momenta

Based on the nonlinear internal-model control (IMC), associated with the suitable commutation strategy, a novel control solution for switched reluctance motor (SRM) is formulated and designed. The commutation strategy uses a definite critical rotor position as commutation point, which reduces the computational burden. The nonlinear IMC-based voltage control scheme for SRM extracts the simplicity of the feedback linearization control and the robustness of IMC structure, which ensures the torque ripple-free and the drive\u27s robustness in spite of the plant-model mismatch disturbances. Some important properties are presented. Simulation results show that the high-performance control for SRM has been achieved.Predloženo je i razrađeno novo rješenje za upravljanje sklopnim reluktantnim motorom (SRM) zasnovano na nelinearnom upravljanju s unutarnjim modelom (IMC) i prikladnoj strategiji komutacije. Strategija komutacije koristi definiranu kritičnu poziciju rotora kao točku komutacije što doprinosi smanjenju računskih zahtjevnosti. Shema za upravljanje naponom SRM-a zasnovana na nelinearnom IMC-u osigurava linearizaciju zatvorenog sustava i robusnost IMC strukture što rezultira ukupnom robusnošću pogona bez oscilacija momenta unatoč nepodudaranju modela smetnji sa stvarnim smetnjama. Opisana su neka važna svojstva ovoga načina upravljanja. Simulacijskim se rezultatima pokazuje visoka kvaliteta upravljanja SRM-a

Modeling and controller design of quasi-Z-Source inverter with battery based photovoltaic power system

A Photovoltaic (PV) power generation system based on quasi-Z-Source inverter (qZSI) with energy storage is presented. A dynamic small-signal model of qZSI with battery is established. Further, the battery power and current double-loop controllers are designed to manage the battery state of charge (SOC). Meanwhile, an improved PQ decoupling control is achieved to smooth the grid-injected power. The obtained simulation and experimental results certify the validity of the proposed control schemes, which provides an efficient method for future energy-storage PV power generation systems

An Effective Control Technique for Medium-Voltage High Power Induction Motor Fed by Cascaded Neutral Point Clamped Inverter

Abstract-An effective control solution for speed sensorless vector control of induction motor fed by a cascaded neutral point clamped (NPC) inverter is proposed, where the novel SPWM pulse rotation control approach provides a simple way to implement vector control for induction motor when the cascaded NPC inverter is employed. The single carrier is used in the novel pulse control, instead of the multi-carriers, which makes the voltage modulation simpler and the hardware burden decrease. It is of great benefits to the cascaded NPC inverter, i.e., the output voltages and powers of all inverter modules, and two series-capacitor dc voltages of each inverter module are perfectly balanced, and a low switch frequency of all inverter modules provides a synthesized high frequency PWM phase voltage. A rotor flux-oriented vector control is combined with back EMF-based MRAS speed estimation, which results in a speed closed-loop control. The voltage sensors together with the filters of changeable parameters ensure the precision of speed estimation for the whole frequency range. The proposed scheme is applied to control an 800kW 4160V induction motor fed by the 1MVA 6000V 17-level cascaded NPC inverter, where the controller mainly consists of one DSP and one CPLD. The experimental results verify the proposed scheme

Germplasm Authentication of Mantis Shrimps (<i>Oratosquilla oratoria</i>) in China Sea by SNP and AS-PCR Method

1471-1473In the study, germplasm authentication of mantis shrimp in China sea was analyzed by SNP and AS-PCR method. Twenty-six stably single nucleotide polymorphisms (SNPs) between Bohai sea and South China sea were revealed, and population-specific primer pairs (BH065/BH326, SC065/SC326) were established based on SNPs. And topological structure analysis separated the mantis shrimps into two distinct lineages with 100% statistical support, which reveals significant divergence has happened in China sea though weak differentiation in morphology. These results showed SNPs and AS-PCR might be the useful tools for germplasm authentication of mantis shrimp

Land-Use Conversion Altered Topsoil Properties and Stoichiometry in a Reclaimed Coastal Agroforestry System

Reclaimed coastal areas were mostly used for agricultural purposes in the past, while land-use conversion was initiated in recent decades in eastern China. Elucidation of the effects of land-use conversion on soil properties and stoichiometry is essential for addressing climate change and ecological conservation. In this study, five land-use types in a reclaimed area were chosen to compare the differences of soil properties and stoichiometry, which comprised paddy, upland, upland-forest, forest, and vegetable garden, with a soil age of about 100 years. The results indicated that these land-use types significantly differed in soil water concentration, pH, bulk density, soil salt concentration, soil organic carbon content, total nitrogen content, and total phosphorus, as well as C:N, C:P, and N:P ratios. Positive correlations were found among soil organic carbon, total nitrogen, and total phosphorus; and among pH, bulk density, and soil salt concentration. Total phosphorus and soil organic carbon contents were the main factors shaping the topsoil among the land-use types. Contents of soil organic carbon, total nitrogen, and total phosphorus in paddy and vegetable garden soils were higher than that in upland and upland-forest soils, while bulk density, pH, and soil salt concentration showed the opposite trends. Forest soil demonstrated intermediate values for most properties. And the highest C:N occurred in the upland and vegetable garden, the highest C:P in paddy and vegetable garden, while the lowest C:N and C:P occurred in upland-forest. The highest and lowest N:P occurred in paddy and upland, respectively. The stoichiometric characteristics presented a narrow range of the ratio, and the C:N:P averaged 48:3:1 similar to the stoichiometry of average Chinese cropland soils. Rotations including legume, the use of organic fertilizers, and appropriate fertilization strategies were suggested for improving cropland management

Land-Use Conversion Altered Topsoil Properties and Stoichiometry in a Reclaimed Coastal Agroforestry System

Reclaimed coastal areas were mostly used for agricultural purposes in the past, while land-use conversion was initiated in recent decades in eastern China. Elucidation of the effects of land-use conversion on soil properties and stoichiometry is essential for addressing climate change and ecological conservation. In this study, five land-use types in a reclaimed area were chosen to compare the differences of soil properties and stoichiometry, which comprised paddy, upland, upland-forest, forest, and vegetable garden, with a soil age of about 100 years. The results indicated that these land-use types significantly differed in soil water concentration, pH, bulk density, soil salt concentration, soil organic carbon content, total nitrogen content, and total phosphorus, as well as C:N, C:P, and N:P ratios. Positive correlations were found among soil organic carbon, total nitrogen, and total phosphorus; and among pH, bulk density, and soil salt concentration. Total phosphorus and soil organic carbon contents were the main factors shaping the topsoil among the land-use types. Contents of soil organic carbon, total nitrogen, and total phosphorus in paddy and vegetable garden soils were higher than that in upland and upland-forest soils, while bulk density, pH, and soil salt concentration showed the opposite trends. Forest soil demonstrated intermediate values for most properties. And the highest C:N occurred in the upland and vegetable garden, the highest C:P in paddy and vegetable garden, while the lowest C:N and C:P occurred in upland-forest. The highest and lowest N:P occurred in paddy and upland, respectively. The stoichiometric characteristics presented a narrow range of the ratio, and the C:N:P averaged 48:3:1 similar to the stoichiometry of average Chinese cropland soils. Rotations including legume, the use of organic fertilizers, and appropriate fertilization strategies were suggested for improving cropland management