arus searah
DESCRIPTION
arus searahTRANSCRIPT
-
Lecture 8 - EE743Direct Current (DC)Machines - Part IIProfessor: Ali Keyhani
-
DC Machines Shunt-connected DC Machine
-
DC Machines The dynamic equations (assuming rfext=0) are:Where Lff = field self-inductance Lla= armature leakage inductance Laf = mutual inductance between the field and rotating armature coils ea = induced voltage in the armature coils (also called counter or back emf )
-
DC Machines
-
DC Machines - Shunt DC Machine Time-domain block diagram The machine equations are solved for:
-
DC Machines - Shunt DC Machine Time domain block diagramG1G3G2LafXXiaififia+
-+
-VaVfVf
-
DC Machines - Shunt DC Machine State-space equationsLetRe-writing the dynamic equations,;
-
DC Machines - Permanent Magnet The field flux in the Permanent Magnet machines is produced by a permanent magnet located on the stator. Therefore,
Lsfif is a constant determined by the strength of the magnet, the reluctance of the iron, and the number of turns of the armature winding.
-
DC Machines - Permanent Magnet Dynamic equations of a Permanent Magnet Machine
-
DC Machines - Permanent Magnet Dynamic equations,
-
DC Machines - Permanent Magnet Time domain block diagram The equations are solved by,
-
DC Machines - Permanent Magnet Time domain block diagram+ - +
-Va G1 G2KvKviaeaKvrrTLTe
-
DC Machines - Permanent Magnet State-space equationsre-writing the equations as function of states,
-
DC Machines - Permanent Magnet In a matrix form,
-
DC Machines - Permanent Magnet Transfer Function,
Let
-
DC Machines - Permanent Magnet The, we will have
Re-arranging the equation,
-
DC Machines - Permanent Magnet In a matrix representation,
-
DC Machines - Permanent Magnet Solving for ia
-
DC Machines - Permanent Magnet Let m be,
The equation is then reduced to,
-
DC Machines - Permanent Magnet
-
DC Machines - Permanent Magnet
-
DC Machines - Permanent Magnet The characteristic equation (or force-free equation) of the system is as shown below,
-
DC Machines - Permanent Magnet If < 1 , the roots are a conjugate complex pair, and the natural response consists of an exponentially decaying sinusoids.If > 1, the roots are real and the natural response consists of two exponential terms with negative real exponents.