The PowerPath project aims to maximise off-grid energy output for rural communities through the delivery of a microgrid interconnecting module featuring remote monitoring and metering for grid stabilisation, along with an innovative solar panel coating that will allow 20-25% increased performance.
The first innovation pillar is the Smart Direct Current (DC)-DC power converter.
Given the typical distance between nanogrids deployed in a representative rural village (25 to 75 metres) and their operation voltage (12 Volts Direct Current (Vdc)/24 Vdc), clustering them within a village-wide balancing grid requires a voltage upgrade to 72 Vdc. This requires DC-DC power converters able to smartly manage energy sharing between the different nanogrids. Such converters, known as “nanogrid interconnection modules” are the first technology developed to make the second step of the lateral electrification model possible.
These interconnection modules are to be installed at each nanogrid and will be composed of:
- A DC-DC bidirectional buck-boost converter dealing with the power exchange
- A command card driving the converter and managing the data recording, the user interface, and the communication with operators for data collection or other interventions
The main features of the suggested energy management system include:
- Secure power balance of the Grid
- Optimised energy flows between interconnected nanogrids
- Monitoring of energy flows
- Optimised Photovoltaic power generation and battery charging
The interconnection module will link a nanogrid to 72 VDC bus of the village-wide DC balancing microgrid and control energy sharing, based on a decentralised and communication-free algorithm. This type of control algorithm avoids a single point of failure and is affordably deployable even in areas where telecommunication signals are inexistent or unreliable. Thus, an interconnection module assesses the local availability of energy through the State-of-Charge of each nanogrid and the global level of energy through the local measurement of the DC bus voltage. A high or a low DC bus voltage means the microgrid is respectively globally charged or discharged. This control algorithm ensures relevant power flows on the DC microgrid while guaranteeing overall stability and maintaining the DC bus voltage within a predefined range of ±10%.
This critical piece of hardware appears on the below graph of a microgrid composed of interconnected nanogrids.
