# Implementation Schemes for Electric Bus Fleets at Depots with Optimized Energy Procurements in Virtual Power Plant Operations

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## Abstract

**:**

## 1. Introduction

## 2. Framework Conditions and Operational Planning

#### 2.1. Modeling Timetable-Based Driving Schedules

#### 2.2. Energy Equivalence and Bus Type-Specific Models

#### 2.3. Charging Concepts and Strategies

## 3. Operation Procedures and Depot Characteristics

#### 3.1. Analysis of Operation Processes and Schedules

#### 3.2. Charging Infrastructure and Process

## 4. Optimized Energy Procurements in VPP Operations

#### 4.1. Implementation Model and Mathematical Formulation

#### 4.2. Computational Study and Dispatch Results

## 5. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Abbreviations

AB | articular bus |

chp | combined heat and power plant |

DD | double decker bus |

dBus | diesel bus |

eBus | electric bus |

em | energy market |

EV | electric vehicle |

EVS/A | electric vehicle supplier/aggregator |

ind | industrial load units |

SB | standard bus |

pv | photovoltaic power plant |

VPP | virtual power plant |

wind | wind power plant |

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**Figure 1.**Framework conditions for the integration of electric bus fleets in the operation scheme of the EVS/A and VPP operator.

**Figure 3.**Approximated energy demands of electric buses (eBus) summarized for defined operating scenarios.

**Figure 4.**Energy demand of an (

**a**) arbitrary electric bus fleet separated by energy demand occurring at (

**b**) first base charging at the depot and (

**c**) second-base charging at termini.

**Figure 5.**Operation processes coordinated by the EVS/A and highlighted charging possibilities at the depot.

**Figure 8.**Charging load at the depot obtained by applying non-controlled and partly-controlled charging.

**Figure 9.**Day-ahead (da) and intraday (id) charging schedules and normalized energy capacity of the spatial and temporal available electric vehicle fleet.

**Figure 10.**Response to positive and negative reserve power requests and performed redispatch measures.

**Figure 11.**Available (

**a**,

**c**) positive and (

**b**,

**d**) negative reserve capacity of the electric bus fleet including the response to (

**a**,

**b**) positive and (

**c**,

**d**) negative reserve power requests.

**Table 1.**Set of unit models ${H}_{\mathrm{mstor}}$ of electric buses (eBus) specified by the energy capacity, weekly mileage, and specific energy demand.

Unit Model | Energy Capacity (kWh) | Weekly Mileage of Driving (km) | Specific Energy Demand (kWh/km) | Daily Energy Demand (kWh) |
---|---|---|---|---|

SB | 175 | 1045/1147/1469 | 1.30/1.80/2.30 | 245–345 |

AB | 225 | 1135/1231/1566 | 1.80/2.50/3.10 | 368–508 |

DD | 250 | 1118/1231/1500 | 1.90/2.60/3.30 | 385–517 |

Fleet Composition | ${\mathit{E}}_{\mathbf{d}}^{\mathbf{fleet},1\mathbf{st}}$ | ${\mathit{E}}_{\mathbf{r}}^{\mathbf{fleet}}$ | |||
---|---|---|---|---|---|

Total | SB | AB | DD | (MWh) | |

193 | 53 | 103 | 37 | 10.59 | 41.53 |

Installed Capacities of Generation, Load and Storage Units (MW) | |||||

Total | Wind | pv | chp | ev | ind |

25 | 6 | 2.5 | 1 | 14.5 | 1 |

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Raab, A.F.; Lauth, E.; Strunz, K.; Göhlich, D.
Implementation Schemes for Electric Bus Fleets at Depots with Optimized Energy Procurements in Virtual Power Plant Operations. *World Electr. Veh. J.* **2019**, *10*, 5.
https://doi.org/10.3390/wevj10010005

**AMA Style**

Raab AF, Lauth E, Strunz K, Göhlich D.
Implementation Schemes for Electric Bus Fleets at Depots with Optimized Energy Procurements in Virtual Power Plant Operations. *World Electric Vehicle Journal*. 2019; 10(1):5.
https://doi.org/10.3390/wevj10010005

**Chicago/Turabian Style**

Raab, Andreas F., Enrico Lauth, Kai Strunz, and Dietmar Göhlich.
2019. "Implementation Schemes for Electric Bus Fleets at Depots with Optimized Energy Procurements in Virtual Power Plant Operations" *World Electric Vehicle Journal* 10, no. 1: 5.
https://doi.org/10.3390/wevj10010005