, evaluation of frequency control application for distributed generation in turkey

Hasan AbuMeteir201441148

2015

, Evaluation of frequency control application for distributed

generation in Turkey,

01/05/2023 2, Evaluation of frequency control application for distributed generation in Turkey,

Introduction Distributed Generation Frequency Control Operational CharacteristicConclusion and suggestions

Outline


Ancillary services are the specialty services and functions provided by the electric grid that facilitate and support the continuous flow of electricity so that supply will continually meet demand. The term ancillary services is used to refer to a variety of operations beyond generation and transmission that are required to maintain grid stability and security.

These services generally include, frequency control, spinning reserves and operating reserves. Traditionally ancillary services have been provided by generators, however, the integration of intermittent generation and the development of smart grid technologies have prompted a shift in the equipment that can be used to provide ancillary services.

Abstract


In this paper, frequency control ability in natural gas fired private power plants connected to medium voltage level is studied.

Data taken from a real power plant operation is used for this study. With the growth of such distributed generation units (DGU) on distribution grid and with the deregulation of the electricity sector, the frequency control may become an applicable scenario for DGU.

Abstract


This paper focus on frequency control of gas engine type power plant because the major portion of renewable units in Turkey are connected directly to the high voltage transmission grid, not the distribution grid.

Introduction


Distributed generation


Distributed energy, also district or decentralized energy is generated or stored by a variety of small, grid-connected devices referred to as distributed energy resources(DER) or distributed energy resource systems.

Distributed energy resource (DER) systems are small-scale power generation or storage technologies (typically in the range of 1 kW to 10,000 kW) used to provide an alternative to or an enhancement of the traditional electric power system.

DER systems typically are characterized by high initial capital costs per kilowatt. DER systems also serve as storage device and are often called Distributed energy storage systems (DESS).



DER systems may include the following devices / technologies:

Combined heat power (CHP), Hybrid power systems (solar hybrid and wind

hybrid systems)Micro combined heat and power (MicroCHP)MicroturbinesPhotovoltaic systems (typically rooftop solar PV)Reciprocating enginesSmall wind power systemsStirling engines



Frequency control refers to the need to ensure that the grid frequency stays within a specific range of the nominal frequency. Mismatch between electricity demand causes variations in frequency and control services are required to bring the frequency back to its nominal value and ensure it does not vary out of range.

Frequency control


The first step is to describe the power system dynamic by the following power balance eq. :

Frequency control


Frequency control


Primary Frequency Control is mainly (P-Controller).The objective of primary frequency control is to

maintain the balance between generation and consumption within the high-voltage European interconnected system. A deviation of this balance will lead to a deviation in the frequency which will automatically trigger the contracted primary reserves to be activated.

Primary Frequency Control


The main function of secondary control system is to correct the deviation dfs and to restore the frequency to the schedule value.

The SFCS limit the drop at an acceptable level.

In the fig. 2 we can see the difference between line 1 which has no FC , while line 2 has a FC .

Secondary Frequency Control


Tertiary frequency control


Tertiary control reserves (UCTE).


Operational Characteristic


Maximum Ramp Rate


Balancing and frequency control occur over a continuum of time using different resources, represented in this figure


Frequency control of MW connected gas turbines and internal combustion engines


Cont


cont


Figure 4 and 5


Realized primary control performance Test


Cont


This paper discusses frequency control ability of generating units focusing on gas engine units. An assessment of frequency control methods have been given in terms of the loading variation and the corresponding power balance equations.

The frequency control of the power system is performed by primary, secondary and tertiary control systems operating in sequence. This is realized in real power plants by changing the output of medium sized power plants automatically or manually at high voltage.

Conclusion and suggestions


The results of primary frequency reserve and sensitivity tests implemented on a real power plant having gas engine units have been evaluated whether or not they satisfy the grid requirements.

Since gas engines can change their output dynamically, they do respond to grid frequency deviation not only at the primary but also at the secondary level if remotely controlled.

As well known, distributed generation units having gas engines have been increasing continuously at medium voltage grid.

These kind of small sized power plants’ engines can easily be utilized in controlling frequency individually or in a group for a secure and reliable operation of distribution grid.

Conclusion and suggestions

, evaluation of frequency control application for distributed generation in turkey

Engineering