Implementation of Resonant Controllers and Filters in Fixed-Point Arithmetic

Resonant controllers and filters are useful in voltage-source-converter control systems. Although the trend is toward implementation in floating-point arithmetic, fixed-point arithmetic is still of interest, but requires much greater care in the algorithm design. This paper covers some important issues, namely, choice of structure, design formulas, scaling, sensitivity, quantization-noise amplification, and suppression of overflow limit cycles. The results presented should be particularly helpful as design guidelines to practical engineers in a situation where one often resorts to trial and error.