Resolver feedback option
25 May 2017
Parker Hannifin has added a resolver feedback option to the AC30P and AC30D units from its highly capable AC30 range of variable speed drives (VSDs).
Updated firmware offers new diagnostic features, on-board communications and support for closed-loop control of PMAC motors when fitted with the new 7004-05-00 resolver feedback option. This enhanced capability makes even the most advanced application accessible to every user.
As well as closed-loop speed control of PMAC or induction motors, the introduction of the innovative resolver feedback option means that the resolver input may also be used as a speed set point, with the drive operating in either closed loop (AC30D only) or open-loop (V/Hz or sensorless) control mode.
Among the other new functionality enhancements in this second phase of the AC30 range development are fully integrated Ethernet IP protocol, parameter data logging to SD card, enhanced 1588 peer-to-peer communications, ‘black box’ trip history recording, a programmable ‘soft’ key on the graphical key pad and PDQ (Parker Drive Quick) tool ‘multi-instance’ capability.
In basic terms, a resolver provides absolute shaft angle feedback to the drive. It is constructed as a rotary transformer with two secondary windings positioned at 90° to each other. A sinusoidal ‘excitation’ voltage is applied to the resolver and two outputs are generated, one scaled by the sine of the shaft angle, the other by the cosine. Parker’s new resolver feedback option measures the relative sizes of the sine and cosine outputs, and converts this into shaft position and shaft speed data.
The resolver feedback option is compatible with AC30P and AC30D drives featuring firmware versions 2.13 and 3.13 (or later). It offers compatibility with a wide range of resolvers from many different manufacturers. A range of resolver connection cables are available for use with NX, MGV, EY, NV and EX motors from Parker.
The AC30 VSD provides users with high levels of control, from simple open-loop pumps and fans, through to closed-loop process line applications. Inherent flexibility and highly modular construction enable a wide range of communications and I/O modules to be easily added as required.