In this article, problems of effectiveness increasing in complex power supply are considered. Disadvantages of centralized power engineering and advantages of power engineering capabilities organization in immediate consumer proximity are presented. Consumer needs satisfaction in electricity, heat supply and cold supply are offered to be realized by conversion of district and quarter boiler houses to trigeneration stations, which are based on gas turbine plants units. In this research, solutions of problem related to lack of fuel gas pressure for gas turbine engine power, which is included in gas turbine plant of trigeneration stations, are suggested. As a result, after considering possible variants of fuel gas pressure increasing, it was decided that there is a perspective of using fuel gas intracyclic compression attachment. Its operating principle involves organization of main steam extraction in heat cycle for booster compressor drive, which compresses fuel gas before its transfer to combustor of gas turbine plant. Results of gas compressor and drive steam turbine design are presented. These parts are included in fuel gas intracyclic compression attachment in specific unit of gas turbine plant. Also, general recommendations about new compressor and turbine stages design for any other units of gas turbine plant are pointed. Further, in the article, two variants of thermal circuit, based on gas turbine plant, are suggested. The first one is a circuit with hot water boiler, where exhaust gas recuperation after turbine is carried out for producing steam, related to fuel gas intracyclic compression attachment demands, and heat system water heating for consumer heat supply system. The second variant involves development of typical gas turbine plant unit in power station with exhaust boiler. There fuel gas intracyclic compression attachment is activated by steam work after exhaust boiler. Then, variants of diagram are compared between each other. Also advantages and disadvantages each of them are considered.