• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.55-58
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• 2003

IPMSM (Interior Permanent Magnet Synchronous Motor) is widely used in many applications such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives. In order to maximize the efficiency in such applications, this paper is proposed the optimal control method of the armature current. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM The proposed control algorithm is applied to IPMSM drive system, the operating characteristics controlled by efficiency optimization control are examined in detail by simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.1 no.1
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• pp.27-37
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• 1996

This paper proposes the control algorithm for maximum efficiency drive of PWM inverter - induction motor system with high dynamic performance. If the induction motor is driven under light load with rated magnetizing current, the Iron loss is excessively large compared with the codder loss which results in doer motor efficiency. Maximum efficiency drive of an induction motor can be achieved by controlling the magnetizing current to satisfy the optimal ratio that leads the total motor loss to be a minimum value at a given speed. The proposed control algorithm essentially uses vector control technique and adopts voltage decoupling control strategy to prevent the degradation of dynamic performance due to reduced magnetizing current. To verify the proposed method, digital simulations and experiments are carried out for a squirrel-cage induction motor with the rating of 2.2[kW].

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.431-434
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• 2002

This paper presents an implementation of direct torque control(DTC) of Reluctance Synchronous Motor(RSM) with an efficiency optimization using the 32bit DSP TMS320C31. The influence of iron loss can not neglected as high speed and precision torque control of RSM, so the optimal current ration between torque current and exiting current analytically derived to drive RSM at maximum efficiency For RSM, torque dynamics can be maintained even with controlling the flux level because the generated torque is direct]y proportional to the stator current. The experimental results for an RSM are presented to validate the applicability of the proposed method. The developed control system is shown high efficiency features with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

• ETRI Journal
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• v.36 no.2
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• pp.280-285
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• 2014

In this paper, the optimal power control problem in a cooperative relay network is investigated and a new power control scheme is proposed based on a non-cooperative differential game. Optimal power allocated to each node for a relay is formulated using the Nash equilibrium in this paper, considering both the throughput and energy efficiency together. It is proved that the non-cooperative differential game algorithm is applicable and the optimal power level can be achieved.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1143-1145
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• 2002

IPMSM (Interior Permanent Magnet Synchronous Motor) is widely used in many applications such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives. In order to maximize the efficiency in such applications, this paper is proposed the optimal control method of the armature current. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM. The proposed control algorithm is applied to IPMSM drive system, the operating characteristics controlled by efficiency optimization control are examined in detail by simulation.

• Journal of Power Electronics
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• v.12 no.2
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• pp.305-316
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• 2012

The paper presents an accurate loss model based controller of an induction motor to calculate the optimal air gap flux. The model includes copper losses, iron losses, harmonic losses, friction and windage losses, and stray losses. These losses are represented as a function of the air gap flux. By using the calculated optimal air gap flux compared with rated flux for speed sensorless indirect vector controlled induction motor, an improvement in motor efficiency is achieved. The motor speed performance is improved using a fuzzy logic speed controller instead of a PI controller. The fuzzy logic speed controller was simulated using the fuzzy control interface block of MATLAB/SIMULINK program. The control algorithm is experimentally tested within a PC under RTAI-Linux. The simulation and experimental results show the improvement in motor efficiency and speed performance.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.776_777
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• 2009

Optimal efficiency control of synchronous reluctance motor(SynRM) is very important in the sense of energy saving and conservation of natural environment because the efficiency of the SynRM is generally lower than that of other types of AC motors. This paper is proposed a novel efficiency optimization control of SynRM considering iron loss using neural network(NN). The optimal current ratio between torque current and exciting current is analytically derived to drive SynRM at maximum efficiency. This paper is proposed an efficiency optimization control for the SynRM which minimizes the copper and iron losses. The design of the speed controller based on adaptive learning mechanism fuzzy-neural networks(ALM-FNN) controller that is implemented using fuzzy control and neural networks. The objective of the efficiency optimization control is to seek a combination of d and q-axis current components, which provides minimum losses at a certain operating point in steady state. The control performance of the proposed controller is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm.

• Journal of the Korean Mathematical Society
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• v.49 no.1
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• pp.99-112
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• 2012

This paper attempts to present a numerical method for solving optimal control problems. The method is based upon constructing the n-th degree Jacobi polynomials to approximate the control vector and use differentiation matrix to approximate derivative term in the state system. The system dynamics are then converted into system of algebraic equations and hence the optimal control problem is reduced to constrained optimization problem. Numerical examples illustrate the robustness, accuracy and efficiency of the proposed method.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1984-1986
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• 1998

This paper presents an optimal efficiency control for the inverter fed induction machine system using neural network. The motor speed and the load torque vary the efficiency characteristics of an induction motor. The optimal slip frequency has nonlinearity varied by the load torque as well as the motor speed. The induction motor is driven using the inverter system and the indirect vector control method which input is slip frequency. The neural network for estimating the optimal slip frequency has two input layer(the motor speed and the load torque) and one output layer(the optimal slip frequency that minimize the input power). Learning algorithm of the neural network is the back-propagation. Using the equivalent circuit including the nonlinearity of the induction motor, the loss reduction is analyzed quantitatively. Experimental results are shown noticeable power savings by proposed scheme in high speed and light load conditions.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.428-433
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• 2001

This paper presents the control algorithm for maximum efficiency drives of an induction motor system with the high dynamic performance. This system uses a simple model of the induction motor that includes equations of iron losses. The model, which only requires the parameters of induction motor, is referred to a field-oriented frame. The minimum point of the input power can be obtained at the steady state condition. The reference torque and flux currents for the vector control of induction motors are calculated by the optimal efficiency control algorithm. The drive system with the proposed efficiency optimization controller has been implemented by a 32 bit floating point TMS320C32 DSP chip. The results show the effectiveness of the control strategy proposed for the induction motor drive.