Abstract
Gas-turbine and gas-piston generator sets (GS) are widely used at distributed generation (DG) facilities. International GS manufacturers configure relay protections (RP) in a way that narrows the acceptable range (AR) and causes properly functioning RPs to effect unnecessary disconnections. It has been shown that the worst disturbances are observed when a microgrid that carries a DG facility is islanded, and power imbalance occurs; when motors start in groups; when the GS’s shed 95% of their output; and when a 3-phase short-circuit occurs in an islanded grid segment. Energy storage units (ESU) are the most recent and highly successful solution to many problems of power engineering. The authors hereof have developed a method that controls active and reactive power of an ESU independently to avoid unnecessary GS disconnections that would otherwise be caused by a short-term deviation in frequency; this will help reliably deliver electricity to the users of an islanded microgrid. Simulation results show that the use of ESUs helps to effectively extend the acceptable range for generator sets. There are recommendations on drawing technical requirements to ES. An important advantage of the proposed ESU power control method is that it does not need to adjust ES-received control actions (CA) online for frequency deviation.
Highlights
International practices have shown that distributed generation (DG) develops worldwide mainly in the form of constructing renewable energy (RE) facilities
Foreign manufacturers configure relay protections (RP) in a way that causes unnecessary generator sets (GS) disconnections at DG facilities when frequencies deviate shortly due to transients; this disrupts electricity delivery to critical users, which entails heavy damage
To prevent unnecessary GS disconnections, this paper proposes the method that independently controls active (∆PESU) and reactive (∆QESU) power output/consumption at a combined Energy storage units (ESU), which comprises a supercapacitor and a li-ion battery
Summary
International practices have shown that distributed generation (DG) develops worldwide mainly in the form of constructing renewable energy (RE) facilities. In Russia, DG facilities are mostly constructed by the owners of industrial facilities and use non-renewable energy (hydrocarbons) As a rule, such facilities are based on gas-turbine units (GTU), gas-piston units (GPU), and diesel-fired generator sets (GS), all of which are imported. Cases have been reported where GS’s were disconnected due to disturbances in an external distribution grid that the microgrid was synchronized with; or within the microgrid, where RPs were functioned correctly as configured This approach to RP configuration on the part of international manufacturers narrows the GS acceptable range (AR), which in case of industrial processes may lead to an accident or an emergency [7,8,9]. The paper shows calculated transients for islanded operation of a DG facility-carrying microgrid; these calculations prove the proposed method to be effective and efficient, as it helps to minimize user damage even in case of a severe disturbance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
