# Development of a New Modelling Concept for Power Flow Calculations across Voltage Levels

^{*}

## Abstract

**:**

## 1. Introduction

#### 1.1. Literature Review and Novelty

#### 1.2. Structure and Objective

## 2. Strategic Network Planning

_{n}may only have a maximum deviation of ∆V

_{max}/V

_{n}= ±10%. In addition, the standards [20,21] for transformers and the standard [22] for power lines regulate the maximum loading under which environmental conditions apply to these equipment. The analyses of the voltage values or voltage value deviations are always carried out with the value V/V

_{n}. V is the measured voltage value at the node and V

_{n}is the nominal voltage of the network level (MV level: V

_{n}= 10 kV; LV level: V

_{n}= 0.4 kV). The analyses of the line loadings or loading deviations are always carried out with the value I/I

_{th}. I represents the measured loading and I

_{th}the maximum permissible thermal limit. The analyses of the transformer loadings or loading deviations are always carried out with the value S/S

_{r}. S represents the measured load and S

_{r}the installed power rating.

#### 2.1. Basic Operational Planning Steps

#### 2.2. Previous Modelling Concept

- HV/MV transformers;
- MV lines;
- MV/LV transformers;
- LV lines.

- -
- Network feed-in on the high voltage side of the HV/MV transformer;
- -
- HV/MV transformer;
- -
- MV lines per MV feeder;
- -
- MV/LV transformers;
- -
- LV equivalent loads per LV network on the low voltage sides of the MV/LV transformers (without modelling of the LV lines) taking into account the SF from the HV/MV transformer perspective.

- -
- Network feed-in at the MV busbar without modelling the HV/MV transformer;
- -
- MV lines per MV feeder;
- -
- MV/LV transformers;
- -
- LV equivalent loads per LV network on the low voltage sides of the MV/LV transformers (without modelling of the LV lines) taking into account the SF from the MV line perspective.

- -
- Network feed-in on the high voltage side of the MV/LV transformer;
- -
- MV/LV transformer;
- -
- LV lines per LV feeder;
- -
- LV loads per house connection, taking into account the SF from the MV/LV transformer perspective to the house connection node.

- -
- Network feed-in at the LV busbar without modelling the MV/LV transformer;
- -
- LV lines per LV feeder;
- -
- LV loads per house connection, taking into account the SF from the LV line perspective to the house connection node.

#### 2.3. Need for a New Modelling Concept

- -
- Preparation of only one network data set;
- -
- File reduction by eliminating the spread of information across multiple data sets;
- -
- Calculation results are consolidated and no longer need to be compiled and analyzed separately;
- -
- Cross-voltage level considerations are simplified with regard to result interpretations and presentations;
- -
- Network data modelling is simplified and reduced, e.g., by restricting import information from new loads to one file where many separate files were previously necessary;
- -
- Effects due to technologies used in, e.g., the MV level (voltage regulation at the HV/MV substation) are immediately evident in all underlying LV networks or upside down (load management in the LV level with repercussions on the MV level);
- -
- Voltage band distribution at MV and LV levels is no longer necessary, as both levels are modelled, and therefore only the specification according to DIN EN 50160 [19] has to be observed;
- -
- Avoidance of network feed-ins to map the higher network level, and thus more accurate modelling of the overlying and underlying networks is possible

## 3. New Modelling Concept

#### 3.1. Structure of the Data Sets

- -
- Network feed-in on the high voltage side of the HV/MV transformers;
- -
- HV/MV transformers;
- -
- MV lines;
- -
- MV/LV transformers;
- -
- MV loads taking into account the SF from the MV/LV transformer perspective on the low voltage sides of the MV/LV transformers;
- -
- LV lines;
- -
- LV loads taking into account the SF from the LV line perspective at the house connection nodes.

#### 3.2. Concept

- CF type 1 is used for the power compensation between the LV line planning perspective and the MV/LV transformer planning perspective to avoid over-dimensioning of the respective MV/LV transformers. The power values in the respective LV feeder remain unaffected by this. The modelling of the CF type is carried out at the low voltage side of each MV/LV transformer.
- CF type 2 is used for the power compensation between the MV/LV transformer planning perspective and the MV line planning perspective. It is modelled on each high voltage side of the MV/LV transformers. Without this CF, the sum of power per MV feeder is too large, since only the number of loads and DER per MV/LV transformer are taken into account in the SF calculation and not the sum of all loads and DER per MV feeder.
- CF type 3 is used for the power compensation between the MV line planning perspective and the HV/MV transformer planning perspective to avoid over-dimensioning of the respective HV/MV transformers. The modelling of the CF type is carried out at the low voltage side of each HV/MV transformer.

#### 3.3. Modelling Example

## 4. Application and Results

^{®}SINCAL (Sincal 19.0 version).

#### 4.1. Data Set

#### 4.2. Modelling of the Previous Concept (Concept 1)

#### 4.2.1. Concept 1a

HV/MV transformers: | V/V_{n} = 102% |

MV lines: | V/V_{n} = 101% |

MV/LV transfomers: | V/V_{n} = 96% |

LV lines: | V/V_{n} = 95% |

#### 4.2.2. Concept 1b

HV/MV transformers: | V/V_{n} = 102% |

MV lines: | Respective voltage values of the low voltage sides of the HV/MV transformers from the planning perspective of the HV/MV transformers |

MV/LV transfomers: | Respective voltage values of the high voltage sides of the MV/LV transformers from the planning perspective of the MV lines |

LV lines: | Respective voltage values of the low voltage sides of the MV/LV transformers from the planning perspective of the MV/LV transformers |

#### 4.3. Modelling of the New Concept (Concept 2)

_{n}= 102% on the high voltage side of the HV/MV transformers are modelled to represent the overlying HV network level.

#### 4.4. Overview of the Concepts for the Analyses

#### 4.5. Analysis and Comparison of Concept 2 with Concept 1a

#### 4.5.1. Voltage Band

- HV/MV Transformers

_{n}= 1% from Figure 6, the assigned voltage band is not fully needed. T1 has a voltage drop of ∆V/V

_{n}= 0.82%, and thus ∆V/V

_{n}= 0.18% of the voltage band remains as a reserve in concept 2. Similarly, a voltage drop of ∆V/V

_{n}= 0.57% takes place over T2; therefore, ∆V/V

_{n}= 0.43% of the voltage band is still available as a reserve in concept 2.

- MV Nodes

_{n}= 0.25% and the median is ∆V/V

_{n}= 0.34% (Figure 21 left). In addition, more than 80% of the deviations are higher than zero (Figure 21 right). This means that the voltage values in concept 2 are higher than in concept 1a. This is due to the fact that the assumed and fixed voltage drop ∆V/V

_{n}= 1% of the HV/MV transformers from concept 1a is not fully required in concept 2. In concept 2, T1 ∆V/V

_{n}= 0.18% and T2 ∆V/V

_{n}= 0.43% of the voltage drop of ∆V/V

_{n}= 1% defined in concept 1a remain unused. Assuming that this is the only factor influencing the voltage value deviations of the MV nodes, the voltage value deviations (depending on which HV/MV transformer the feeder is connected to) should be ∆V/V

_{n}= 0.18% or ∆V/V

_{n}= 0.43%, respectively. However, this does not correspond to the voltage value deviations shown. These range from ∆V/V

_{n}= −0.35% to ∆V/V

_{n}= 0.43% (Figure 21). Therefore, there must be other factors influencing the deviation of the voltage values.

_{n}= 101% (voltage value of the network feed-in in concept 1a) and approx. V/V

_{n}= 99.5% and the deviations drop from ∆V/V

_{n}= 0.43% (unused voltage drop over T2) to ∆V/V

_{n}= 0.24%. The decreasing positive voltage value deviations can be explained by the fact that the MV node voltage values in concept 2 fall more sharply due to the higher network losses already mentioned (lack of LV line modelling and MV/LV transformer loading). Thus, the deviation along the feeder becomes smaller. In the lower data range of the diagram on the right (abscissa: voltage values from concept 1a) the voltage values are between V/V

_{n}= 101% (voltage value of the network feed-in in concept 1a) and approx. V/V

_{n}= 99% and the deviations change from ∆V/V

_{n}= 0.18% (unused voltage drop over T1) to ∆V/V

_{n}= −0.35%. As in the upper data range, the change in the deviations along the voltage values can be explained by the stronger voltage drop in concept 2 along the feeder due to higher network losses. A negative deviation means that concept 2 has lower voltage values than concept 1a. Thus, the stronger voltage drops in concept 2 affected the deviations up to negative values.

- MV/LV Transformers

_{n}= −0.01% and the median is ∆V/V

_{n}= −0.02% (both left diagram). Concept 2 achieves a lower voltage drop (negative deviation) at the MV/LV transformers for 75% of MV/LV transformers. In about 67% of MV/LV transformers, there is a deviation between ∆V/V

_{n}= −0.1% and ∆V/V

_{n}= 0.0%. In the diagram on the right (Figure 23), it can also be seen that there are differences in voltage drop when the MV/LV transformers are differentiated in customer transformers (CTs) and distribution transformers (DTs). In the case of CT, there are only lower voltage drops in concept 2 (negative deviations). The deviations of the voltage drops at the DT show that a large part of it is negative. However, there are also some MV/LV transformers with positive deviations of the voltage drop, and thus higher voltage drops in concept 2.

_{n}= 4% and ∆V/V

_{n}= 6%. These higher voltage values result in lower loadings, and thus lower voltage drops at the MV/LV transformers in concept 2.

- LV Nodes

_{n}= 4.1% and a median of ∆V/V

_{n}= 4.5%. They are significantly higher in concept 2 than in concept 1a. This is caused by the voltage band distribution that is not fully needed in the higher network levels.

_{n}= 4.1%, the LV line sections are less loaded and this results in a lower voltage drop along the LV lines. Consequently, the further away the LV nodes are from the MV/LV transformers, the higher the voltage value deviations between concept 2 and concept 1a.

#### 4.5.2. Equipment Loading

- HV/MV Transformers

_{r}= 5.7% and of T2 with ∆S/S

_{r}= 4.7% is higher than in concept 1a. This is due to the power flows at the HV/MV transformers (Figure 28 right). These are higher in concept 2 because higher network losses of the underlying network levels are taken into account. Again, this is because the LV lines are modelled in concept 2 in difference to concept 1a. As a result, LV line losses occur in concept 2, which are not included in concept 1a. In addition, in concept 2, the loadings of the MV lines and the MV/LV transformers are modelled from their respective planning perspective. This leads to higher loadings and thus to higher network losses in concept 2 than in concept 1a.

- MV Lines

_{th}= 2.17% and the median is ∆I/I

_{th}= 1.05%. Almost all MV line loadings are higher in concept 2 than in concept 1a. The exception is a single line, consisting of eight line sections, which only supplies a single large MV load. Due to the higher voltage values (see Figure 21), the line loadings of these sections are lower (∆I/I

_{th}= −0.051%).

- MV/LV Transformers

_{r}= 2.37% and the median is ∆S/S

_{r}= 1.08%. Around two-thirds of all loading values have a positive deviation. This means that the loading is higher in concept 2. Again, this is primarily due to the additional LV line losses in concept 2 because the LV lines are loaded from their respective planning perspective. The MV/LV transformers therefore have to supply the LV line losses from the LV line perspective. This is countered by the higher voltage values (Figure 25) on the high voltage side of the MV/LV transformers in concept 2. As a result, the MV/LV transformer loadings are potentially lower. These two effects work in opposite directions and result in most deviations being small. The right-hand diagram in Figure 32 shows that the deviations of CT are only negative. Thus, the voltage drops are smaller in concept 2. This is due to the higher voltage values at the MV/LV transformer nodes on the high voltage side, as there are no LV line losses at CT. In the case of DT, most of the loadings on the MV/LV transformers are higher due to the additional LV line losses.

- LV Lines

_{th}= −1.73% and the median is ∆I/I

_{th}= −0.88%. The line loadings of all LV line sections are lower in concept 2 than in the LV line perspective of concept 1a (negative deviation). This is due to the deviation of the voltage values (see Figure 26). Due to the higher average voltage values of ∆V/V

_{n}= 4.1%, the line loadings in concept 2 are lower at the same electric current. The LV line sections with a deviation of ∆I/I

_{th}= 0% are unloaded and represent lines at the end of a feeder without loads.

#### 4.5.3. Network Losses

#### 4.5.4. Interim Conclusion

#### 4.6. Analysis and Comparison of Concept 2 with Concept 1b

#### 4.6.1. Voltage Band

_{n}= 102%) at the network feed-ins at the HV/MV transformer nodes on the overvoltage side. In the modelling of concept 1a and concept 1b, there are no differences due to the same voltage value of the network feed-in.

_{n}= −0.1% and the median is ∆V/V

_{n}= −0.06% between concept 2 and concept 1b. All deviations are zero or negative, which means that there is a higher voltage drop in concept 2 than in concept 1b. This is due to the higher network losses of the underlying network levels, which are loaded by their respective planning perspectives. It can be seen that in concept 1b the voltage values are higher than in concept 1a. This is due to the fact that the difference between concept 2 and concept 1a is caused only by the partially used voltage band of the HV/MV transformers. This unused voltage band leads to lower voltage values in concept 1a compared to concept 1b.

_{n}at the MV/LV transformers. There are no or very small deviations of ∆V/V

_{n}= ±0.001% of the voltage drop at the CT. For the DT, the average deviation is ∆V/V

_{n}= 0.09% and the median is ∆V/V

_{n}= 0.03%. It also shows that all deviations in the DT are higher than or equal to zero. Thus, the voltage drops in concept 2 are higher at the MV/LV transformers than in concept 1b. If the deviations of the voltage drop between concept 1a and concept 1b are compared, they are smaller in concept 1b (negative deviation). This can be explained by the higher voltage values at the MV/LV transformers and LV nodes in concept 1b. These lead to lower equipment loadings and, as a result, to lower network losses. Thus, the voltage drops in concept 1b are lower than in concept 1a due to the higher voltage values and lower network losses.

_{n}of the LV nodes. It can be seen that there are no significant differences between the voltage values of the two concepts. The right-hand diagram in Figure 40 shows the voltage value deviations at the LV nodes between concept 1a and concept 1b. It can be seen here that the voltage values are higher in concept 1b, as there is no fixed voltage band distribution as in concept 1a.

#### 4.6.2. Equipment Loading

_{th}between concept 2 and concept 1b and Figure 41 on the right the deviations of the line loadings ∆I/I

_{th}between concept 1b and concept 1a. The average deviation between concept 2 and concept 1b is ∆I/I

_{th}= 2.23% and the median is ∆I/I

_{th}= 1.08%. There are only minor differences between concept 1b and concept 1a. As a result, the deviations between concept 2 and concept 1b are relatively similar to the divergences between concept 2 and concept 1a. The higher loadings in concept 2 are caused by the lack of modelling of the LV lines in concept 1b and the loading of the underlying networks from the considered planning perspective in concept 1b.

_{r}= 3.8% and the median is ∆S/S

_{r}= 1.6%. The CT analysis shows that there are no deviations between concept 2 and concept 1b. The deviations in the loadings of the MV/LV transformers are caused by the different LV line losses in the two concepts. When comparing concept 1b and concept 1a, it can be seen that the loadings in concept 1b are lower. This is due to the higher voltage values in concept 1b.

_{th}= −0.0003%. The right-hand diagram in Figure 43 shows the deviations of the loadings between concept 1a and concept 1b. These are caused by the different voltage values at the LV nodes in concept 1a and concept 1b.

#### 4.6.3. Network Losses

#### 4.6.4. Interim Conclusion

_{th}= 370%) are present in some cases. Due to these high overloads of the equipment, very high network losses occur at the overloaded equipment. These increasingly lead to significant differences in the power flow results of the concepts. Therefore, in a final step in Section 4.7, the network is replanned and the comparison is then carried out again.

#### 4.7. Analysis of the Overplanned Networks

_{max}/V

_{n}= ±10% of DIN EN 50160 [19] at all nodes during permissible operation and the equipment is not loaded above I/I

_{th}= 100%. This results in the new LF results shown below.

_{r}= 5.7% to ∆S/S

_{r}= 2.6% and of T2 from ∆S/S

_{r}= 4.7% to ∆S/S

_{r}= 2.9%. The deviations of the voltage drops and loadings in the MV network level have been reduced by nearly 50%. The overplanning of the MV/LV transformers reduced the deviation of the voltage drops by an average factor of 3. The largest deviations have been reduced by a factor of up to 6 (largest deviation reduced from ∆V/V

_{n}= 0.49% to ∆V/V

_{n}= 0.075%). The average deviation of the loading of the MV/LV transformers is reduced by a factor of 2.5 and the largest deviations are reduced by a factor of up to 4. As in the unplanned network, the deviations in the LV network level are almost non-existent. The maximum deviation of the line loading has been reduced from ∆I/I

_{th}= −0.052% in the unplanned network to ∆I/I

_{th}= −0.001% in the planned network. The maximum deviation of the voltage values has been reduced from ∆V/V

_{n}= 0.004% to ∆V/V

_{n}= 0.001%.

## 5. Discussion

#### 5.1. Method Reflection

#### 5.2. Influence of the General Conditions

#### 5.3. Fuzziness of Network Modelling

## 6. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

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**Figure 7.**(

**Left**): Voltage values of the HV/MV transformer nodes, (

**right**): Loadings of the HV/MV transformers; both concept 1a.

**Figure 8.**

**(Left**): Voltage values of the MV nodes, (

**right**): Loadings of the MV line sections; both concept 1a.

**Figure 9.**

**(Left**): Voltage values of the MV/LV transformer nodes, (

**right**): Loadings of the MV/LV transformers; both concept 1a.

**Figure 10.**(

**Left**): Voltage values of the LV nodes, (

**right**): Loadings of the LV line sections; both concept 1a.

**Figure 11.**(

**Left**): Voltage values of the HV/MV transformer nodes, (

**right**): Loadings of the HV/MV transformers; both concept 1b.

**Figure 12.**(

**Left**): Voltage values of the MV nodes, (

**right**): Loadings of the MV line sections; both concept 1b.

**Figure 13.**(

**Left**): Voltage values of the MV/LV transformer nodes, (

**right**): Loadings of the MV/LV transformers; both concept 1b.

**Figure 14.**(

**Left**): Voltage values of the LV nodes, (

**right**): Loadings of the LV line sections; both concept 1b.

**Figure 15.**(

**Left**): Voltage values of the HV/MV transformer nodes, (

**right**): Loadings of the HV/MV transformers; both concept 2.

**Figure 16.**(

**Left**): Voltage values of the MV nodes, (

**right**): Loadings of the MV line sections; both concept 2.

**Figure 17.**(

**Left**): Voltage values of the MV/LV transformer nodes, (

**right**): Loadings of the MV/LV transformers; both concept 2.

**Figure 18.**(

**Left**): Voltage values of the LV nodes, (

**right**): Loadings of the LV line sections; both concept 2.

**Figure 21.**Voltage value deviations of the MV nodes between concept 2 and concept 1a (Inverted square brackets exclude the number from the specified range).

**Figure 22.**Voltage value deviations of the MV nodes between concept 2 and concept 1a as functions of the node voltage values.

**Figure 23.**Voltage drop deviations of the MV/LV transformers between concept 2 and concept 1a. (Inverted square brackets exclude the number from the specified range).

**Figure 24.**Voltage drop deviations of the MV/LV transformers between concept 2 and concept 1a as a function of the loading deviations of the MV/LV transformers.

**Figure 25.**(

**Left**): Distribution of the voltage value deviations on the high voltage sides of the MV/LV transformers between concept 2 and concept 1a, (

**right**): Distribution of the voltage value deviations on the low voltage sides of the MV/LV transformers between concept 2 and concept 1a (Inverted square brackets exclude the number from the specified range).

**Figure 26.**Voltage value deviations of the LV nodes between concept 2 and concept 1a (Inverted square brackets exclude the number from the specified range).

**Figure 27.**Voltage value deviations of the LV nodes between concept 2 and concept 1a as functions of the node voltage values.

**Figure 28.**(

**Left**): Loadings of the HV/MV transformers in concept 2 and concept 1a, (

**right**): Power flows of the HV/MV transformers in concept 2 and concept 1a.

**Figure 29.**Loading deviations of the MV line sections between concept 2 and concept 1a (Inverted square brackets exclude the number from the specified range).

**Figure 30.**Loading deviations of the MV line sections between concept 2 and concept 1a as a function of the line loadings.

**Figure 31.**Percentage deviations of the load of the LV networks from the MV line planning perspective (load incl. LV line losses and MV/LV transformer losses from MV line planning perspective) between concept 2 and concept 1a.

**Figure 32.**Loading deviations of the MV/LV transformers between concept 2 and concept 1a. (Inverted square brackets exclude the number from the specified range).

**Figure 33.**Loading deviations of the MV/LV transformers between concept 2 and concept 1a (only distribution transformers) as a function of the deviations of the network losses (apparent power in kVA).

**Figure 34.**Loading deviations of the LV line sections between concept 2 and concept 1a (Inverted square brackets exclude the number from the specified range).

**Figure 35.**(

**Left**): Percentage loading deviations of the absolute loadings of the LV line sections between concept 2 and concept 1a as a function of the voltage value deviations of the starting nodes of the LV lines between concept 2 and concept 1a, (

**right**): Loading deviations of the LV line sections between concept 2 and concept 1a as a function of the LV line loadings.

**Figure 37.**(

**Left**): Deviation of the equipment losses of the equipment in the respective network level between concept 2 and concept 1a, (

**right**): Deviation of the network losses of equipment in the different planning perspectives of concept 1a between concept 2 and concept 1a.

**Figure 38.**(

**Left**): Voltage value deviations of the MV nodes between concept 2 and concept 1b, (

**right**): Voltage value deviations of the MV nodes between concept 1b and concept 1a.

**Figure 39.**(

**Left**): Voltage drop deviations of the MV/LV transformers between concept 2 and concept 1b, (

**right**): Voltage drop deviations of the MV/LV transformers between concept 1a and concept 1b.

**Figure 40.**(

**Left**): Voltage value deviations of the LV nodes between concept 2 and concept 1b (further decimal places were not output in the network calculation software), (

**right**): Voltage value deviations of the LV nodes between concept 1a and concept 1b.

**Figure 41.**(

**Left**): Loading deviations of the MV line sections between concept 2 and concept 1b, (

**right**): Loading deviations of the MV line sections between concept 1a and concept 1b.

**Figure 42.**(

**Left**): Loading deviations of the MV/LV transformers between concept 2 and concept 1b, (

**right**): Loading deviations of the MV/LV transformers between concept 1a and concept 1b.

**Figure 43.**(

**Left**): Loading deviations of the LV line sections between concept 2 and concept 1b, (

**right**): Loading deviations of the LV line sections between concept 1a and concept 1b.

**Table 1.**Resulting power values for the example network in Figure 5 (bold formatting represents the respective power value for each planning perspective).

Viewing Area | Number of Loads | P in kW from Planning Perspective LV Lines | P in kW from Planning Perspective MV/LV Transformers | P in kW from Planning Perspective MV Lines | P in kW from Planning Perspective HV/MV Transformer |
---|---|---|---|---|---|

1 load | 1 | 22.71 | 20.15 | 19.14 | 19.14 |

1 LV feeder | 2 | 45.42 | 40.30 | 38.28 | 38.28 |

1 MV/LV transformer | 4 | 90.84 | 80.60 | 76.56 | 76.56 |

1 MV feeder | 8 | 181.68 | 161.20 | 153.12 | 153.12 |

1 HV/MV transformer | 8 | 181.68 | 161.20 | 153.12 | 153.12 |

Parameter | Value | Unit |
---|---|---|

Power rating of the HV/MV transformers | 31.5 | MVA |

MV line length | 56.4 | km |

MV feeders | 14 | pieces |

Distribution stations | 53 | pieces |

Customer stations | 26 | pieces |

LV line length | 135 | km |

House connections | 3286 | pieces |

Metering points | 13,893 | pieces |

Private charging points | 5303 | pieces |

Public charging points | 501 | pieces |

Electric heat pumps | 1014 | pieces |

**Table 3.**Summary of key findings from the comparison of the evaluations of concept 2 and concept 1a.

Equipment | Parameter | Concept 2 | |
---|---|---|---|

Effect | Justification | ||

HV/MV transformers | Voltage values | Lower | Higher voltage drop |

Voltage drop | Higher | Higher network losses | |

Loading | Higher | Higher network losses | |

Network losses | Higher | Loading of the equipment from their respective planning perspective, additional modelling of LV lines | |

MV nodes/ MV lines | Voltage values | Higher | Voltage band of the HV/MV transformer network level not fully utilized |

Lower | Higher network losses | ||

Loading | Higher | Higher network losses | |

Network losses | Higher | Loading of the equipment from their respective planning perspective, additional modelling of LV lines | |

MV/LV transformers (DT) | Voltage values | Higher | Voltage band of the overlying network levels is not fully utilized |

Voltage drop | Higher Lower | Higher network losses Higher voltage values | |

Loading | Higher Lower | Higher network losses Higher voltage values | |

Network losses | Higher | LV line loading from their respective planning perspective | |

MV/LV transformers (CT) | Voltage values | Higher | Voltage band of the overlying network levels is not fully utilized |

Voltage drop | Lower | Higher voltage values | |

Loading | Lower | Higher voltage values | |

Network losses | Lower | Higher voltage values | |

LV nodes/ LV lines | Voltage values | Higher | Voltage band of the overlying network levels is not fully utilized |

Loading | Lower | Higher voltage values | |

Network losses | Lower | Higher voltage values |

Equipment | Parameter | Concept 2 | |
---|---|---|---|

Effect | Justification | ||

HV/MV transformers | Voltage values | Lower | Higher voltage drop |

Voltage drop | Higher | Higher network losses | |

Loading | Higher | Higher network losses | |

Network losses | Higher | Loading of the equipment from their respective planning perspective, additional modelling of LV lines | |

MV nodes/ MV lines | Voltage values | Lower | Higher network losses |

Loading | Higher | Higher network losses | |

Network losses | Higher | ||

MV/LV transformers (DT) | Voltage values | Lower | Higher voltage drops |

Voltage drop | Higher | Higher network losses | |

Loading | Higher | Higher network losses | |

Network losses | Higher | LV line loading from their respective planning perspective | |

MV/LV transformers (CT) | Voltage values | Equal | Equal network losses |

Voltage drop | Equal | Equal network losses | |

Loading | Equal | Equal network losses | |

Network losses | Equal | No network losses through underlying network levels | |

LV nodes/ LV lines | Voltage values | Equal | Equal network losses |

Loading | Equal | Equal network losses | |

Network losses | Equal |

Equipment | Parameter | Concept 2 | |
---|---|---|---|

Effect | Justification | ||

HV/MV transformers | Voltage values | Lower | Higher voltage drop |

Voltage drop | Higher | Higher network losses | |

Loading | Higher | Higher network losses | |

Network losses | Higher | ||

MV nodes/ MV lines | Voltage values | Lower | Higher network losses |

Loading | Higher | Higher network losses | |

Network losses | Higher | ||

MV/LV transformers (DT) | Voltage values | Lower | Higher voltage drop |

Voltage drop | Higher | Higher network losses | |

Loading | Higher | Higher network losses | |

Network losses | Higher | LV line loading from their respective planning perspective | |

MV/LV transformers (CT) | Voltage values | Equal | Equal network losses |

Voltage drop | Equal | Equal network losses | |

Loading | Equal | Equal network losses | |

Network losses | Equal | No network losses through underlying network levels | |

LV nodes/ LV lines | Voltage values | Equal | Equal network losses |

Loading | Equal | Equal network losses | |

Network losses | Equal |

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## Share and Cite

**MDPI and ACS Style**

Riedlinger, T.; Wintzek, P.; Zdrallek, M.
Development of a New Modelling Concept for Power Flow Calculations across Voltage Levels. *Electricity* **2024**, *5*, 174-210.
https://doi.org/10.3390/electricity5020010

**AMA Style**

Riedlinger T, Wintzek P, Zdrallek M.
Development of a New Modelling Concept for Power Flow Calculations across Voltage Levels. *Electricity*. 2024; 5(2):174-210.
https://doi.org/10.3390/electricity5020010

**Chicago/Turabian Style**

Riedlinger, Tobias, Patrick Wintzek, and Markus Zdrallek.
2024. "Development of a New Modelling Concept for Power Flow Calculations across Voltage Levels" *Electricity* 5, no. 2: 174-210.
https://doi.org/10.3390/electricity5020010