1. Terminology, abbreviations and definitions
1.1 Abbreviations
This section contains the abbreviations used in the document.
1.1.1 df/dt
df/dt denotes the frequency change as a function of time. See section 6.2 for a more detailed description.
1.1.2 f<
f< denotes the operational setting for underfrequency in the relay protection.
See section 6.2 for a more detailed description.
1.1.3 f>
f> denotes the operational setting for overfrequency in the relay protection. See section 6.2 for a more detailed description.
1.1.4 fR
fR denotes the frequency at which a plant is to begin downward regulation with the agreed droop. See section 5.2.1 for a more detailed description.
1.1.5 In
The rated current In is the maximum continuous current that a plant or an elec-tricity-generating unit is designed to deliver. See section 1.2.35 for a more de-tailed description.
1.1.6 IQ
The reactive current delivered or absorbed by a plant is referred to as IQ. 1.1.7 PM
PM indicates the active power which can be generated under the given circum-stances.
1.1.8 Pn
Pn denotes the rated power of a plant. See section 1.2.36 for a more detailed description.
1.1.9 PCC
Point of Common Coupling (PCC). See section 1.2.22 for a more detailed de-scription.
1.1.10 PCI
Point of Connection in Installation (PCI) is the point in the installation where the plant is connected and where consumption is connected. See section 1.2.25 for a more detailed description.
1.1.11 PCOM
Point of Communication (PCOM). See section 1.2.23 for a more detailed de-scription.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.1.12 PF
Power Factor (PF). See section 1.2.28 for a more detailed description.
1.1.13 PGC
Point of Generator Connection (PGC) is the point defined by the supplier of an electricity-generating unit as the unit's terminals. See section 1.2.26 for a more detailed description.
1.1.14 POC
Point of Connection (POC). See section 1.2.24 for a more detailed description.
1.1.15 Uc
UC denotes the normal operating voltage. See section 1.2.14 for a more detailed description.
1.1.16 Umax
Umax denotes the maximum value of the nominal voltage Un that a plant may be exposed to.
1.1.17 Umin
Umin denotes the minimum value of the nominal voltage Un that a plant may be exposed to.
1.1.18 Un
Un denotes the nominal voltage. The voltage is measured phase to phase. See section 1.2.13 for a more detailed description.
1.1.19 UPGC
UPGC denotes the voltage measured on the electricity-generating unit's termi-nals. See section 1.2.26 for a more detailed description.
1.1.20 UPOC
UPOC denotes the normal operating voltage in the POC. See section 1.2.24 for a more detailed description.
1.1.21 Ux
Ux where x indicates the relay configuration for undervoltage steps 1 (<) or 2 (<<) as well as overvoltage steps 1 (>), 2 (>>) or 3 (>>>). See section 6.2 for a more detailed description.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.2 Definitions
This section contains the definitions used in the document. Several definitions are based on IEC 60050-415:1999, but have been modified for the purpose.
1.2.1 Absolute power constraint
Adjustment of active power to a maximum level is indicated by a set point. The +/- tolerance of the set point adjustment is referred to as the absolute power constraint. See section 5.2.2.1 for a more detailed description.
1.2.2 Balance-responsible party for production
A balance-responsible party for production is financially accountable to the transmission system operator.
The balance-responsible party for production holds the balance responsibility for a given plant vis-à-vis the transmission system operator.
1.2.3 Droop
Droop is the angle of a curve which a control function must follow.
1.2.4 Electricity-generating unit
An electricity-generating unit is a unit which generates electricity, and which is directly or indirectly connected to the public electricity supply grid.
1.2.5 Electricity supply undertaking
The electricity supply undertaking is the enterprise to whose grid a plant is con-nected electrically. Responsibilities in the public electricity supply grid are dis-tributed onto several grid companies and one transmission enterprise.
The grid company is the company licensed to operate the public electricity sup-ply grid up to 100 kV.
The transmission enterprise is the enterprise licensed to operate the public elec-tricity supply grid above 100 kV.
1.2.6 Emergency power unit
An emergency power unit is a unit connected to an installation for the purpose of supplying electricity in situations where the public electricity supply grid is unable to supply electricity.
1.2.7 Flicker
Flicker is a visual perception of light flickering caused by voltage fluctuations.
Flicker occurs if the luminance or the spectral distribution of light fluctuates with time. At a certain intensity, flicker becomes an irritant to the eye.
1.2.8 Frequency response
Frequency response is the automatic downward regulation of active power as a function of grid frequencies above a certain frequency fR with a view to stabilis-ing the grid frequency. See section 5.2.1 for a more detailed description.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.2.9 Generator convention
The sign for active/reactive power indicates the power flow seen from the gen-erator. The consumption/import of active/reactive power is indicated by a nega-tive sign, while the generation/export of acnega-tive/reacnega-tive power is indicated by a positive sign.
The sign of the Power Factor set point is used to determine whether control should take place in the first or the fourth quadrant. For Power Factor set points, two pieces of information are thus combined into a single signal: A set point value and the choice of control quadrant.
Figure 1 Definition of sign for active power, reactive power, Power Factor set points and reference for Power Factor angle.
1.2.10 Grid company
A licensed company which operates the distribution grid. The grid company is the enterprise to whose grid a plant has been connected electrically.
1.2.11 Harmonic distortions
Harmonic distortions are defined as electrical disturbances caused by overhar-monic currents and voltages. Haroverhar-monic distortions are also referred to as over-tones, overharmonic over-tones, overharmonic distortion or simply harmonics.
1.2.12 Limiting component
The limiting component is the component in a plant which defines/limits the rated power of the plant.
For example, a plant owner can install solar panels larger than the active power limit for a specific plant category if the inverter is limited to and sealed at a
Technical regulation 3.2.1 Terminology, abbreviations and definitions
maximum active power output corresponding to the category in which the plant is to be placed. In this case, the inverter is the limiting component. For wind turbines or other generator types, the limiting component could be power elec-tronics, a subsystem or the control unit which controls the active power output from the plant.
1.2.13 Nominal voltage (Un)
The voltage at the POC which defines a grid and to which operational character-istics are referred. The voltage is measured phase to phase. Nominal voltage is denoted by Un.
The internationally standardised voltage levels are shown in Table 1.
1.2.14 Normal operating voltage (Uc)
Normal operating voltage indicates the voltage range within which a plant must be able to continuously generate the specified rated power, see sections 3.1 and 3.2. Normal operating voltage is determined by the electricity supply un-dertaking and is used to determine the normal production range.
1.2.15 Normal production
Normal production indicates the voltage/frequency range within which a plant must be able to continuously generate the specified rated power, see sections 3.1 and 3.2.
1.2.16 Plant
A plant consists of one or more electricity-generating units, which are defined in more detail in section 1.2.4. The plant is connected to the public electricity sup-ply grid through one Point of Connection.
1.2.17 Plant categories
Plant categories in relation to the total rated power in the Point of Connection:
A1. Plants up to and including 11 kW
A2. Plants above 11 kW up to and including 50 kW B. Plants above 50 kW up to and including 1.5 MW C. Plants above 1.5 MW up to and including 25 MW D. Plants above 25 MW or connected to over 100 kV.
1.2.18 Plant component
A plant component is a component or subsystem which is part of an overall plant.
1.2.19 Plant infrastructure
The plant infrastructure is the electrical infrastructure between the Point of Generator Connection (PGC) of the individual electricity-generating units in a plant and up to the Point of Connection (POC).
1.2.20 Plant operator
The plant operator is the enterprise responsible for the operation of a plant, either through ownership or contractual obligations.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.2.21 Plant owner
The plant owner is the legal owner of a plant. In certain situations, the term company is used instead of plant owner. The plant owner is entitled to hand over the operational responsibility to a plant operator.
1.2.22 Point of Common Coupling (PCC)
The Point of Common Coupling (PCC) is the point in the public electricity supply grid, where consumers are or can be connected.
The Point of Common Coupling and the Point of Connection may coincide elec-trically. The Point of Common Coupling (PCC) is always located farthest into the public electricity supply grid, i.e. farthest away from the plant, see Figure 2 and Figure 3.
The electricity supply undertaking determines the Point of Common Coupling.
1.2.23 Point of Communication (PCOM)
The Point of Communication (PCOM) is the point in a plant, where the data communication properties specified in section 7 must be made available and verified.
1.2.24 Point of Connection (POC)
The Point of Connection (POC) is the point in the public electricity supply grid, where the plant is or can be connected, see Figure 2 and Figure 3.
All requirements specified in this regulation apply to the Point of Connection. By agreement with the electricity supply undertaking, reactive compensation at no load can be placed elsewhere in the public electricity supply grid. The electricity supply undertaking determines the Point of Connection.
Figure 2 shows a typical installation connection of one or more plants indicating the typical locations of the Point of Generator Connection (PGC), Point of Con-nection (POC), Point of ConCon-nection in Installation (PCI) and the Point of Com-mon Coupling (PCC). In the example shown, the Point of ComCom-mon Coupling (PCC) and the Point of Connection (POC) coincide.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
Demand
Wind turbine PCC / POC
PGC: Point of Generator Connection
= terminals of the generator POC: Point Of Connection
= grid connection point
PGC
PGC
PV module 1
PGC PV module 2
PGC
PV module 3 PCC: Point of Common Coupling
= point of delivery
PCOM: Point of COMmunication
= communication interface point
PCI
PCOM
SCADA / Gateway
PCI: Point of Connection in Installation
= installation connection point Voltage level < 1 kV
Figure 2 Example of installation connection of a plant.
Figure 3 shows a typical grid connection of several plants indicating where the Point of Generator Connection (PGC), Point of Connection (POC), Point of Com-mon Coupling (PCC) and the voltage reference point can be located. The voltage reference point is either in the Point of Connection (POC), the Point of Common Coupling (PCC) or a point in between.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
Figure 3 Example of grid connection of a plant.
1.2.25 Point of Connection in Installation (PCI)
The Point of Connection in Installation (PCI) is the point in the installation where electricity-generating units in the installation are connected or can be connected, see Figure 2 for the typical location.
1.2.26 Point of Generator Connection (PGC)
The Point of Generator Connection is the point in the plant infrastructure, where the terminals/generator terminals for the electricity-generating unit are located.
The Point of Generator Connection for a plant is the point defined by the manu-facturer as the electricity-generating unit's terminals.
1.2.27 Positive list
A so-called positive list has been prepared to facilitate the technical approval process for grid connection of category A1 and A2 plants. The list contains plant components deemed to comply with the specific property and functionality re-quirements under the relevant technical regulations.
The positive list is available at the Danish Energy Association's website:
www.danskenergi.dk/positivlister.
1.2.28 Power Factor (PF)
The Power Factor, cosine φ, for AC voltage systems indicates the ratio of the active power P to the apparent power S, where P = S*cosine φ. Likewise, the reactive power Q = S*sinus φ. The angle between current and voltage is denot-ed by φ.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.2.29 Power Factor control
Power Factor control is the control of the reactive power proportionately to the active power generated. See section 5.3.2 for a more detailed description.
1.2.30 Power infrastructure
The power infrastructure is the part of the public electricity supply grid that connects the POC and PCC.
1.2.31 Public electricity supply grid
Transmission and distribution grids, the purpose of which is to transmit elec-tricity for an indefinite group of elecelec-tricity suppliers and consumers on terms laid down by public authorities.
The distribution grid is defined as the public electricity supply grid with a max-imum nominal voltage of 100 kV.
The transmission grid is defined as the public electricity supply grid with a nom-inal voltage above 100 kV.
1.2.32 Q control
Q control is the control of the reactive power independent of the active power generated.
1.2.33 Ramp rate constraint
Ramp rate constraint is a function controlling the interval of active power with a set point-defined maximum increase/reduction (ramp rate) of the active power.
See section 5.2.2.2 for a more detailed description.
1.2.34 Rapid voltage changes
Rapid voltage change is defined as a brief isolated voltage change (RMS). Rapid voltage changes are expressed as a percentage of normal operating voltage.
1.2.35 Rated current (In)
Rated current In is defined as the maximum continuous current that a plant is designed to provide under normal operating conditions. Rated current is denot-ed by In.
1.2.36 Rated power of a plant (Pn)
The rated power of a plant is the highest level of active power that the plant is designed to continuously provide and which appears from the type approval.
The rated power is denoted by Pn. 1.2.37 Transmission enterprise
Enterprise licensed to operate the transmission grid. The transmission enter-prise is the enterenter-prise in whose grid the distribution grid, or the plant, is electri-cally connected.
1.2.38 Transmission system operator
Enterprise entrusted with the overall responsibility for maintaining security of supply and ensuring effective utilisation of the public electricity supply grid.
Technical regulation 3.2.1 Terminology, abbreviations and definitions
1.2.39 Voltage fluctuation
Voltage fluctuation is a series of rapid voltage changes or a periodic variation of the root-mean-square (RMS) value of the voltage.
Technical regulation 3.2.1 Objective, scope of application and regulatory provisions