a) Write the general d-q matrix of three phase system and also simplify the matrix at the given angles 0=0,0=90, Vac=500V. (02 Marks) b) Calculate the space vectors for phase voltage using the above d-q matrix for the following vectors and also calculate the reference voltage and angle and find the modulation index? (04 Marks) [la] [2/3 1) = -1/3 (-1/3] -1/31 = 2/3 -1/3] 2)