Trying to grasp the idea behind your circuit first I see an op-amp inverting integrator (R4, C1 and U1)... then a current-inversion NIC (INIC) injecting a current through the capacitor that is proportional to the voltage across it.

Really, the INIC is floating and it should be supplied by separate voltage sources VB1, VB2. The two equal resistors R2, R3 and the op-amp U2 form a non-inverting amplifier with a gain of two... but I think these 200 ohm resistances (400 ohm voltage divider in the negative feedback) are too low.

Trying to grasp the idea behind your circuit first I see an op-amp non-inverting integrator (R4, C1 and U1)... then a current-inversion NIC (INIC) injecting a current through the capacitor that is proportional to the voltage across it.

Really, the INIC is floating and it should be supplied by separate voltage sources VB1, VB2. The two equal resistors R2, R3 and the op-amp U2 form a non-inverting amplifier with a gain of two... but I think these 200 ohm resistances (400 ohm voltage divider in the negative feedback) are too low.