Offgrid solar controller connection in rectifier system and battery

i am working in mobile company… we have mobile tower where equipment run both A/C and DC system through rectifier.

Now I have connected a solar controller in my rectifier bus-bar system. and set voltage higher like 57V DC and my rectifier output is 54V DC.

But I notice that during grid availability, my solar controller does not give any output but when main grid off its start giving output. means my load is not taking power from solar system when main grid is available.

If you know any solution, plz let me know.