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TMS320F28388D: Question on parameters used for resolver i/f in Digital Power SDK project / TIDM-02009

Part Number: TMS320F28388D
Other Parts Discussed in Thread: TIDM-02009

I am looking at TIDM-02009 from the Digital Power SDK for reference code for working with a resolver.  Is there documentation or otherwise some guidance on what these parameters are and if and how some of the resolver parameters can be adjusted for a given application?

Thanks!

From trinv_settings.h:

#define RESOLVER_BIAS   2.40f           // Bias between Resolver zero and Id

#define RESOLVER_OMEGA (200.0f * 2.0f * PI)
#define RESOLVER_ZETA 0.7f
#define RESOLVER_PHASE_COMP_GAIN - 4.6585E-5f

#define RESOLVER_LPF_SPD_BW 100.0

from trinv.c:

resolver_init(&resolver1);
resolver1.resolver_theta = &resolver_theta;
resolver1.resolver_omega = &resolver_omega;
resolver1.sample_time = 1.0f / (RESOLVER_EXC_FREQUENCY * 1000.0f);
resolver1.pll_gain_in = RESOLVER_OMEGA * RESOLVER_OMEGA;
resolver1.pll_gain_ff = 2.0f * RESOLVER_ZETA / RESOLVER_OMEGA;
resolver1.bias = RESOLVER_BIAS;
resolver1.phase_comp_gain = RESOLVER_PHASE_COMP_GAIN;
FILTER_FO_init(&resolver1.lpf_spd, RESOLVER_LPF_SPD_BW,
(RESOLVER_EXC_FREQUENCY * 1000.0f));

  • Hi Mark,

    The RESOLVER_OMEGA and RESOLVER_ZETA are the bandwidth and damping ratio of the resolver position tracking PLL loop. RESOLVER_BIAS is the angle difference between your electric zero position and the resolver zero position. RESOLVER_PHASE_COMP_GAIN is the gain used to compensate for time difference between your resolver position output and your FOC feedback sampling. RESOLVER_LPF_SPD_BW is the bandwidth of the LPF for speed output.

    Please let me know if you have further questions. Thanks.

    Han

  • Thank you, Han.

    Do you have any detail on how the values were chosen for these parameters in TIDM-02009?

  • Mark,

    The parameters are chosen primarily from targeted electric speed of the motor and electrical characteristics of the signal chain on your control board.

    Han