16 Journal of International Conference on Electrical Machines and Systems vol. 1, no. 4, pp. 16~22 , 2012 16 Novel Claw-Pole Eddy-Current Load for Testing DC Counter- Rotating Motor – Part II: Design and Modeling ` Khalil Kanzi *, Sam Roozbehani *, Abolfazl Dehafarin*and Majid Kanzi* Abstract – Eddy current brakes are electromechanical devices used as variable mechanical loads for testing electrical machines. Accurate modeling of eddy current loss is an important t factor for optimum design of eddy brake systems. In this second part, we propose novel formulations of eddy current loss in novel claw-pole eddy brake system. The proposed model for eddy current loss in novel claw-pole eddy brake system depends on the size of the claw poles. Also, in this paper, the flux density is measured by using the magnetic circuit of the novel claw pole. The model results are compared with experimental results and they are found to be in good agreement. Keywords: Claw-Pole Eddy Current Brake, Counter-Rotating Motor, Load Testing, Eddy Current Loss 1. Introduction An eddy current brake is a new assistant brake system of large scale vehicles, e.g. modern high-speed trains, and plays an important role in the braking force induced within. We can expect economization, safety and a decrease in driver fatigue by using this type of brake [1]. If the coils shown in Fig.1 are excited by a direct current and the disk is a solid iron body, eddy currents are induced in the iron by the relative motion between the disk and the magnetic field generated by the iron core. Interaction of the magnetic field and the induced eddy currents produces a retarding torque which is a function of the DC excitation current, rotor speed, and magnetic and electric properties of solid iron. Such a device can therefore be used as a load for testing the electric motor. The retarding torque of an eddy current brake is calculated as a function of the angular velocity of the disk and the DC current of the magnetizing coil [2]. In order to optimize the design of the brake system, it is necessary to estimate the braking force, the distribution of magnetic flux and eddy current loss. Many researchers have investigated much on the development of accurate measurement methods and analytical or numerical models for the eddy current force or eddy current loss. In [3]-[5], braking and attracting forces are calculated for different train speeds and excitation currents by using FEM. Finally, numerical results are compared with measurements. In [6], a new model is implemented in MATLAB to evaluate eddy current brakes. The model generates the characteristic curves of the brake being calculated from its configuration, dimensions and materials used. Also, in [7], a FEM method based approach is used to determine an eddy current brake model's parameters, i.e. equivalent resistance and reactance. The present paper, together with a companion paper (Part I) [8], deals with the construction, design and modeling of the novel claw pole of the eddy current load constructed for testing counter-rotating motors. As shown in Fig.2, the construction of the testing system is includes the counter-rotating motor (CRM) [9], eddy current loads and current sources. Motor   DC V Disk Shaft Flux Coil Iron Core Motor Torque Retarding Torque Fig.1. Schematic configuration of eddy current brake * Iranian Academic Center For Education, Culture and Research ACECR K.N Toosi University of Technology Branch( Khkanzi@jdnasir.ac,ir, a_dehafarin@jdnasir.ac.ir) Received 03 July 2012 ; Accepted 05 October 2012