This paper proposes an adaptive modified least mean fourth (MLMF) control scheme with perturb and observe (P&O) technique for a voltage source converter (VSC) connected to solar photovoltaic array (SPV), three single-phase non-linear loads in a three-phase, 4-wire system with DSTATCOM (Distributed Static Compensator) capabilities. The adaptive control scheme based on MLMF shows low mean square error and converges faster. The system is modelled and simulated for power factor correction and zero voltage regulation modes. Due to single stage topology, the system shows high efficacy at high voltages. The neutral load current is well compensated by the VSC's fourth leg current. The harmonics in grid currents are well under the IEEE-519 standard.