Allocation of the distribution generator (DG) in distribution system faces many challenges. The selection of the best location and capacity of the DG must be carefully selected as this affects the performance and stability of the system. This paper proposes the application of particle swarm optimization technique to find the optimum allocation of DG in the distribution network for active and reactive power compensation to reducing power losses and enhancement the voltage profile. The main objective of the paper is to determine an appropriate location and size for different types of DG and investigate the impact of battery energy storage system (BESS) in the distribution systems. Proposed technique is tested standard IEEE 33-bus is simulated in MATLAB to indicate the effectiveness of the PSO algorithm in solving the optimization problems of placement and sizing of multi-type DGs. and the obtained results are compared without distributed generation. The simulation results ensure the ability of the proposed algorithm for achieving the goals.