A new smart grid system is widely used for energy supply system because it is simple, available, low cost, high efficiency and environmentally friendly. Conventionally, inverter techniques are utilised to convert input DC into output AC with the same frequency and phase. This process suffers the same problem which is a higher harmonic distortion, phase synchronisation, lower quality of waveform and long distance, among others. In this paper, three phase synchronous inverters (PSI) were used to direct synchronous PWM control, LCL filter, three phase RLC load, three phase Yg-Delta transformer, 5 km feeder with 2 MW load. PWM was used to generate the pulse signal for synchronisation. However, LCL filters were used to remove the noise in inverter output and transformer output side of the design. A balanced three phase load (10 kVAR) and also the input DC voltage 500 V were considered in this design. Three phase transformer (100kVA/260V/25kV) was used to increase the inverter output voltage and current with the fundamental frequency (50 Hz). The system conversion efficiency was 99.96% and phase synchronous error for each phase was approximately 4.5 degrees.