Brushless PM VSDs, using either brushless PM or brushless DC motors, achieve the highest overall power efficiency over wide speed and torque ranges. (Higher motor power efficiencies lead to better energy savings.) The brushless PM motor will develop the highest power per-unit-volume, or power density, of the three motor technologies represented in this article.
Two brushless PM VSDs, the 120-watt BX5120 and the 90-watt AXU590A, also from Oriental Motor, illustrate this point. The higher performance closedloop BX5120 uses an optical encoder to provide the necessary velocity feedback and a three-piece inverter as the power electronics drive. This higher cost VSD creates the highest precision speed regulation signals (0.05%) as a function of load or voltage or temperature variations over a wide speed range of 100 to1.
The lower cost AXU590A uses a hall device as the closed-loop feedback to achieve a smaller speed range, but has better speed regulation (as a function of load, voltage, and temperature variations) than the brush DC VSD. This unit also has the smallest volume and the highest power density of all the devices discussed in this article, and is often used in smaller-sized, more portable machines. Both three-phase inverter driven brushless PM VSDs possess superior life cycle performance and much lower EMI signatures than the DC VSD.
Two brushless PM VSDs, the 120-watt BX5120 and the 90-watt AXU590A, also from Oriental Motor, illustrate this point. The higher performance closedloop BX5120 uses an optical encoder to provide the necessary velocity feedback and a three-piece inverter as the power electronics drive. This higher cost VSD creates the highest precision speed regulation signals (0.05%) as a function of load or voltage or temperature variations over a wide speed range of 100 to1.
The lower cost AXU590A uses a hall device as the closed-loop feedback to achieve a smaller speed range, but has better speed regulation (as a function of load, voltage, and temperature variations) than the brush DC VSD. This unit also has the smallest volume and the highest power density of all the devices discussed in this article, and is often used in smaller-sized, more portable machines. Both three-phase inverter driven brushless PM VSDs possess superior life cycle performance and much lower EMI signatures than the DC VSD.
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