Papers by Keyword: Variable Speed Drive

Abstract: This paper presents a study of efficiency improvement in the oil pipeline system. Instead of using only control valve, the original system of two oil pumps which have rating of 1,850 kW each is redesigned by using variable speed drive (VSD) technology together with the control valve. This proposed installation method of VSD will be performed to adjust and open the control valve fully at 100%. Furthermore, the frequency control method of the VSD also depends on types of oil. In the efficiency analysis of the oil pipeline system, four types of oil that is JET A1, Disel, B91, and B95 having different density coefficient will be used respectively. The new and the original data acquisition of relationships between transported oil quantity of each type per period and consumed power are compared. From the sequent results, it can be confirmed that this proposed method used to the practical analysis in accordance with Affinity Law can be applied to not only improve the efficiency and also save cost of the power consumption up to 42.96%.

Abstract: An air conditioning (AC) system design requires two main aspects that should be taken into consideration, there are reducing energy consumption and ensuring thermal comfort. This paper present variable speed drive on compressor motor is being tested to reduce the energy consumption. Conventional AC system to use on/off controller where the compressor motor turns itself on and runs at maximum speed then turns back off to achieve the temperature setting. This controller consumes more energy, however, by using a variable speed drive, the compressor motor will constantly run at various speeds while achieving the temperature setting. A system that developed software to implement the controller algorithms was installed in a thermal environmental room with data acquisition to monitor the room temperature, energy consumption, energy saving and coefficient of performance. Measurements were taken during the one hour experimental period at a time interval of three minutes for temperature set-points of 22, 23 and 24°C with internal heat loads of 500, 700 and 1000 W. The proposed technique can save energy and thermal comfort in comparison with conventional on/off control. The experiment results indicate that the application of variable speed drive on compressor motor is better than conventional on/off.

Abstract: Advanced high-voltage (≥10 kV) silicon carbide (SiC) devices described in this paper have the potential to significantly impact the system size, weight, high-temperature reliability, and cost of modern variable-speed medium-voltage (MV) systems such as variable speed (VSD) drives for electric motors, integration of renewable energy including energy storage, micro-grids, traction control, and compact pulsed power systems. In this paper, we review the current status of the development of 10 kV-20 kV class power devices in SiC, including MOSFETs, JBS diodes, IGBTs, GTO thyristors, and PiN diodes at Cree. Advantages and weakness of each device are discussed and compared. A strategy for high-voltage SiC power device development is proposed.

Abstract: According to characteristics of permanent magnet synchronous servo motor driven constant pump hydraulic system, and relevant parameters of the motor, the pump and the oil, an indirect measurement system for flow based on soft-sensing model is established. The measurement of the output flow of constant pump is realized easily by measuring the speed of the motor. And the accuracy of measurement of the model has been improved with the oil viscosity-temperature behavior, viscosity-pressure characteristic and the conditions fuzzy compensation coefficient. Experimental results show that the soft-sensing model is of enough accuracy and has an excellent response.

Abstract: The paper proposes an algorithm for control of processes based on variable-speed drives with low acceleration and deceleration rate of the motor, which determines the dynamics of the whole control system. The results of investigation of the controller based on the proposed algorithm are presented and discussed. The controller provides good transient performance of the control system response in case when the drives with different motor acceleration and deceleration rates are used.

Abstract: This paper presents investigation results of the influence of the supply voltage amplitude variation law on the efficiency of AC induction motor in variable-speed drive based on the frequency converter. It is demonstrated that the commonly employed linear and square voltage amplitude variation laws do not provide the highest efficiency of the AC induction motor. The corrected AC voltage amplitude variation dependences for different motor load torque, at which high efficiency of the motor supplied by the frequency converter is maintained, are proposed and discussed. Reported experimental study was performed on a special test bench.