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This article presents propagation of current sensor error through $dq$ -transform and the propagated error effect on high-frequency injection (HFI)-based self-sensing control. Three-phase ac systems use Clark and Park transform with $a, b, c$ phase inputs for control purpose, i.e., $dq$ -transform. When error exists in $a, b, c$ inputs, e.g., due to quantization, gain, offset, noise, and others, the error propagates to $d$ - and $q$ -axes and $dq$ -transform becomes inaccurate; therefore, the control performance degrades. Statistical models based on variance are developed for 2- and 3-channel based $dq$ -transform. The error variance models are verified using the error probability density function (PDF) with uniformly distributed random inputs. It is shown that the error propagated in $dq$ -axes and self-sensing control performance become rotor position-dependent, following the error variance model with error that exists in current inputs. It is shown that the error variance of 2-channel based $dq$ -transform becomes three times higher on average compared to 3-channel based $dq$ -transform. It is demonstrated that 3-channel based self-sensing control results in lesser position estimation error compared to 2-channel based self-sensing with a tradeoff in an additional sensor in the machine drive system.

A pin-HEMT receiver for multi-Gbit/s heterodyne detection systems is described. The receiver uses discrete, packaged devices and a simple hybrid construction to achieve a band-width of 10 GHz and a noise level not exceeding 13.5 pA/&sqrt;(Hz). A sensitivity of −32.5 dBm is demonstrated at 4 Gbit/s using CP-FSK over 100 km of conventional single mode fibre.