Frequency Dependent Behavior of a Dynamo-Type HTS Flux Pump

Modelling the Frequency Dependence of the Open-Circuit Voltage of a High-T c Superconducting Dynamo

“…Above 50 Hz, the "HTS only" model continues to exhibit a linear increase in DC output voltage with increasing frequency, as expected from Faraday's law. However, for the "Full wire" and "Full wire, heat" models, the rate at which the DC output voltage increases reduces with increasing frequency, which becomes more noticeable above around 50 Hz, similar to that observed in experiments [16][17][18][19]. In addition, there is little difference observed with and without heating.…”

“…In this work, we attempt to explain the frequency dependence of HTS dynamos reported in the literature [16][17][18][19], where it is observed that the rate at which the open-circuit DC voltage increases reduces with increasing frequency, in contrast to the expected linear behaviour. The common explanation for this frequency-dependent behaviour is that the heat generated in the HTS wire is the cause [16][17][18][19]. An alternative explanation is offered here: the interaction between and current flow in the different layers of the HTS wire as the frequency of the dynamo increases.…”

Sensitivity analysis and machine learning modelling for the output characteristics of rotary HTS flux pumps

“…Four groups of simulations were arranged to primarily illustrate the relations between the controllable design parameters and the open circuit voltage of the rotary HTS flux pump, where in each group only one of the four aforementioned parameters is altered while the others remain constant. Figure 3(a) shows the frequency response within the input range from 10 to 100 Hz, aligning with the frequency range used in experimental results in [19]. It is worthwhile mentioning that a perfect linear relation was observed in [19] as the frequency increased from zero until a turning point was captured at approximately 100 Hz, which can attribute to the current interactions between different layers of the HTS tape [46][47][48][49] under high frequency.…”

“…Figure 3(a) shows the frequency response within the input range from 10 to 100 Hz, aligning with the frequency range used in experimental results in [19]. It is worthwhile mentioning that a perfect linear relation was observed in [19] as the frequency increased from zero until a turning point was captured at approximately 100 Hz, which can attribute to the current interactions between different layers of the HTS tape [46][47][48][49] under high frequency. The single layer numerical model is not suitable for manifesting the multi-layer current interactions related phenomenon, hence the frequency is limited to 100 Hz to avoid this issue.…”

A half-bridge HTS transformer–rectifier flux pump with two AC field-controlled switches

“…There has been much recent work detailing the physical mechanisms behind HTS flux pumps [6] [7] [8], the theory of operation of HTS flux pumps [9] [10] and results from different HTS flux pumps operating under various conditions [9] [10][11] [12]. There is an identified need in the field of HTS flux pumping for a bridging of the gap between basic physical theory and operational performance.…”