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I am working on a single phase PLL (phase locked loop) and I would like to make a phase shift by using orthogonal signal generator non frequency dependent. I have found many method like transport delay, inverse park transformation, Hilbert transformation, or Second Order Generalized Integrator (SOGi) but none of them fit my model. i have to shift alpha which has the same amplitude and phase to the grid voltage to 90 degree by using non-frequency dependent method. I am working in a PLECS program

enter image description here

I have tried to draw the circuit which is answerd, first after the loop filter I have got a phase shift with 180 then when I connect to flip flop I got zero output. please can you tell me where is my mistake. I have found another answer which is connection between two op-amp first shift by 180 then by 90 degrees but the problem when I apply very high frequencies i don't get a 90 degrees phase shift. please find attach the pictures of two models enter image description here

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Use a master oscillator running at four times the grid frequency, and divide it down to 4 quadrature signals. Lock one of them in phase to your reference. Another will then be at exactly 90 degrees to it.

schematic

simulate this circuit – Schematic created using CircuitLab

A lot of this can be integrated into a 4046 IC, the phase detector and clk oscillator and parts of the loop filter. All you need to add is the /4 shown as the two D registers. An HC74 would be the ideal component for this.

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  • \$\begingroup\$ Thank you for your reply, I haven't used a master oscillator before, you meant should I insert an amplyfier with resistor and capacitor in parallel and resistor in series, then i have to divide the signal by 4 and get a phase shift 90 degrees. for me it is not clear. \$\endgroup\$ – Fadi Feb 6 '16 at 13:54
  • \$\begingroup\$ dear thank for your answer, I have tried to draw the circuit you suggest me, first after the loop filter I have got a phase shift with 180 then when I connect to flip flop I got zero output. please can you tell me where is my mistake. I have found another answer which is connection between two op-amp first shift by 180 then by 90 degrees but the problem when I apply very high frequencies i don't get a 90 degrees phase shift. please find attach the pictures of two models [![enter image description here][2]][2] \$\endgroup\$ – Fadi Feb 12 '16 at 14:22
  • \$\begingroup\$ @Fadi It would help if you drew the circuit the same as mine, then you might get the same behaviour. \$\endgroup\$ – Neil_UK Feb 12 '16 at 17:55
  • \$\begingroup\$ 'Similar' is not close enough. It needs to be identical. Next question? \$\endgroup\$ – Neil_UK Feb 12 '16 at 21:07
  • \$\begingroup\$ i have copy your circuit, what is the wrong i have done in the first picture, hope u don't be nervous from the same topic but i dont know if the phase detector is presented like i have done plus loop filter thank you \$\endgroup\$ – Fadi Feb 14 '16 at 22:31

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