Vektorově orientované řízení synchronního stroje s permanentními magnety. Eliminace snímačů fázový ch proudů s využitím modelu stroje a s kompenzací nelinearit střídače

Field-oriented control of permanent magnet synchronous machine. Elimination of phase current sensors with using of machine model and with compensation of non-linearities of the inverter

book

Czech

During last fifteen years AC electric drives appear in man’s everyday life. On the other hand before these drives were privilege of special automation fields and military applications. The expansion was caused by availability of advanced AC drives. To realize quality drive is necessary high dynamics power semiconductors devices, high performance control circuits and reliable dynamic electric machine. Modern power IGBT and MOSFET transistors meet requirements for semiconductor devices. These parts record certain level of integration. Anti-parallel diode is implemented in package of transistor as a standard. Also more than one transistor is made in one package to create complete branch of inverter or complete bridge of threephase inverter. Furthermore these devices are equipped with drivers and protective circuits in package to control directly by logic signals. For control of inverters are used modern DSP with good performance and equipped with peripherial devices to manage complete service of drive. Important parts of drives are feedback sensors. There are used sensors of electrical quantities (voltage, current) and motion sensors (speed and position). For various reasons exist tendencies to eliminate several of these sensors and was developed some methods. The best known for elimination of current sensors is using shunt resistor in DC link circuit. To eliminate position sensor are used methods based on Kalman filters and specially for PMSM is developed method known as “sliding mode position observer”. These thesis are oriented to eliminate phase current sensors in field-oriented control of permanent magnet synchronous motor. Proposed method uses model based on voltage equations of PMSM to compute stator current in rotating reference frame d-q. Thorough principle of method doesn’t include all differences from ideal motor and ideal inverter. In thesis are developed methods to compensate non-idalities of inverter, especially DC link voltage ripple compensation, impact of dead times and impact of voltage drops on output voltage of inverter and their compensations. Also is described estimation of real resistance of stator winding changing it’s value with temperature based on thermal model of electric machine. The method allows simplifying a hardware structure of inverter. It is possible to remove current sensors from output terminals. This method requires position sensor to ensure field orientation during control and DC link voltage sensor to compensate its ripples. Using these method was realized an inverter for backup power source for aeroplane with fuel turbine. Controlling of the inverter was made by 16 – bit microprocessor Intel 87C196KR. There were developed algorithms for PWM, model for computing of stator current, current and speed regulators. Simulations and realization confirm principle of the method. The accuracy of stator current control depends on model settings accuracy and on quality of compensation of inverter and machine non-idealities. Benefits of results are developing of new method of PMSM control without current sensors and making of analysis of open-loop system non-idealities and developing of their compensation.

Sensorless Control, PMSM, Field-oriented Control

KLÍMA, B.

20. 11. 2002

B. Klíma - diseratční práce

UVEE, FEKT, VUT v Brně

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