FOC控制中采用等幅值Clark变换时瞬时功率计算公式为

直流母线功率为

假设逆变器损耗为0，则两式相等

根据上面功率不变原则，可以计算得到母线电流Idc，可以参考Odrive代码如下

float mod_to_V = (2.0f / 3.0f) * vbus_voltage;
float V_to_mod = 1.0f / mod_to_V;
float mod_d = V_to_mod * Vd;
float mod_q = V_to_mod * Vq;
ictrl.Ibus = mod_d * Id + mod_q * Iq;
其中vbus_voltage为母线电压，Vd Vq分别为电流环输出的Ud和Uq，Id Iq为Park变换后得到的Id Iq,ictrl.Ibus为估算的母线电流
Tips:这是采用等幅值Clark变换的母线电流估算方法，根据实际工程需求可对估算母线电流进行滤波

Odrive该部分源码（foc.cpp）贴在这下面

 // Current error
    float Ierr_d = Id_des - Id;
    float Ierr_q = Iq_des - Iq;

    // TODO look into feed forward terms (esp omega, since PI pole maps to RL tau)
    // Apply PI control
    float Vd = ictrl.v_current_control_integral_d + Ierr_d * ictrl.p_gain;
    float Vq = ictrl.v_current_control_integral_q + Ierr_q * ictrl.p_gain;

    float mod_to_V = (2.0f / 3.0f) * vbus_voltage;
    float V_to_mod = 1.0f / mod_to_V;
    float mod_d = V_to_mod * Vd;
    float mod_q = V_to_mod * Vq;

    // Vector modulation saturation, lock integrator if saturated
    // TODO make maximum modulation configurable
    float mod_scalefactor = 0.80f * sqrt3_by_2 * 1.0f / sqrtf(mod_d * mod_d + mod_q * mod_q);
    if (mod_scalefactor < 1.0f) {
        mod_d *= mod_scalefactor;
        mod_q *= mod_scalefactor;
        // TODO make decayfactor configurable
        ictrl.v_current_control_integral_d *= 0.99f;
        ictrl.v_current_control_integral_q *= 0.99f;
    } else {
        ictrl.v_current_control_integral_d += Ierr_d * (ictrl.i_gain * current_meas_period);
        ictrl.v_current_control_integral_q += Ierr_q * (ictrl.i_gain * current_meas_period);
    }

    // Compute estimated bus current
    ictrl.Ibus = mod_d * Id + mod_q * Iq;