Microgrid at KBFSC
Radio Studio played a major role in the design, installation and commissioning of a microgrid at KBFSC. KBFSC (Kuala Belalong Field Studies Centre) is a biological research center of the University of Brunei, Darussalam and is nested in a valley between two hills in Brunei forests. KBFSC helps scientists from all over the world study local flora and fauna in an actual setting.
KBFSC is out of reach of normal civilisation. Access is only for research scientists. UBD assists scientists to reach there on chartered boats.
KBFSC is powered using Diesel Generators. The center provides excellent infrastructure for conducting field surveys and studies. Accomodation and dining facilities for visiting scientists are comparable to the best in the world.
Radio Studio’s innovations that were used:
- jPlugs were used to do appliance level measurement of ACs and other heavy loads like driers that exceeded 2kW for brief periods of time. As of writing, there is no comparable appliance level monitor that could be installed so easily in such a setting.
- Motion Sensing LED lights for pathway
- DC driven lights with bi-directional motion triggering and pre-settable idle illumination.
- Diesel consumption meter with Wi-Fi transport
- These meters delivered diesel consumed with network synchronised time-stamp enabling computation of instantaneous efficiencies of generator. These could also be used to study latencies in power conversion.
- DC jPlugs
- For bi-directional battery monitoring with remote ON/OFF control.
Motivation for Microgrid
Since KBFSC is part of a sensitive eco-system, the impact to the environment is required to be as minimal as possible. Diesel generators are therefore run only when absolutely needed. Demand for power is needed for basic lighting and fans (to combat humidity, which is above 90 on average) and also to run basic research equipment like charging laptops, cameras, driers and refrigerators. On an average, the generators are turned on for 8-9 hours per day. This decreases productivity since researchers would like more time available to them during their visit.
A microgrid was proposed to help the eco-system and increase productivity. The objective of the microgrid was to ensure that power was available for 24 hours without increasing the average running hours of the diesel generator.
System Level Architecture
A microgrid was envisaged to provide automated management at
- Source Management – Adding renewables to augment power generation, determining time of use of generators
- Storage Management – Introduction of storage
- Load Management – By load grouping into primary and secondary loads, by distributing storage, by separating distribution (there was one distribution network exclusively for networking and computing), by use of more efficient products like LED lamps, direct DC powering, etc….
- Demand Management – This was done using a scheduler. The interface to the scheduler was a touch-screen which accepted inputs from the user with regard to when a particular service was required to be run. For instance, if a person wants to run a washing machine, the person enters the time and date and the scheduler would try to meet his/her demand without sacrificing efficiency goals.
All the management functionality was implemented by IBM Research. Radio Studio provided all the hardware and did the system integration, installation and commissioning with Universiti Brunei Darussalam. Radio Studio was involved in the hardware architecture and hardware solution design. The solution delivered involved use of readily available off-the-shelf equipment with Radio Studio’s custom hardware wherever such hardware was not readily available.
Stages of development
- Estimate Consumption of Energy
- Load Grouping
- Introduction of Storage
- Introduction of Renewables
- Management Infrastructure
Estimate Consumption of Energy
For a small-size center, KBFSC has a great number of varied appliances that ran on electricity. Some of them were ACs in the lab to combat humidity. Specimens collected by scientists need to be preserved either by drying or by immersion in a suitable solution. Humidity dealt a death blow to drying efforts and ACs were used to facilitate drying than for human comfort. Each AC consumed 1.5kW on an average.
Drier Cabinets – These were powered by electricity and were used to ensure the integrity of dried specimens. Exposure to humidity runs the risk of fungus attack on precious lab specimens. There are few units and each consumed upto 2kW.
- Instant Water Heaters – For hot bath – 2kW peak
- Driers – For drying after washing. Peak consumption of 2kW.
- Other small scale, but numerous lights and fans.
jPlugs were used to measure consumption. jPlug provided very fine temporal and spatial consumption for each appliance and studies were made as to effective hours of operation over months to determine average energy needs. A Wi-Fi network was installed to enable jPlugs to push data to a local server.
Lighting loads were measured on a block level using 3-phase conzerv meters. an RS485 backbone collected the data from these meters and pushed them to the local server.
Radio Studio designed a meter to measure the amount of diesel consumed. This was done by introducing a reed-switch based rotary flow-meter into the diesel distribution system. Flows were integrated to measure the amount of fuel. This was necessary since the diesel generator was old and did not deliver fuel readings. Further integrating the diesel generator’s control system to IBM’s data collection system was difficult.
With this system in place, IBM Research were able to determine the total electrical energy consumed and the total fuel that was needed.
On each block, the primary loads and secondary loads were separated. Primary loads were concerned with basic infrastructure needed, like lights, fans and sockets and secondary loads were the ones that needed to be scheduled and included washing machines, driers, heaters, etc…
The Center also had a long pathway and this was proposed to be done with motion sensing DC powered LED lights. The only difference from conventional motion sensing lamps were that they need to produce minimal illumination when there was no motion. The reason was obvious – when there is no light, the place is pitch dark and little illumination was needed. Radio Studio’s motion sensing lights delivered optimal light at optimum efficiency. The design of the system involved alternating connection of lights and sensors such that each light was triggered by two sensors and each sensor in turn triggered two lights.
The need for storage was obvious, and the need was for an architecture which will enable distributed storage with scheduling capability. Controls for charging were put in place using DC jPlugs developed by Radio Studio. The architecture consisted on about 25kWH of battery storage using 2V OPzV batteries from Hoppecke and Conext XW inverters. The battery charging could be controlled using a 200A DC relay. Radio Studio developed special drivers for energising these relays with minimal energy footprint.
Conext XW inverters were chosen on their higher charging current capability, PV integration and high surge current delivery. COMBOX from Schneider was used to log the data from the inverters for analytics by IBM Research.
Diesel generator load could now be optimised by switching ON/OFF charging capability.
Since the center was situated in a tropical rainforest with tall trees and dense vegetation, there was no scope for wind or large-scale PV. The only possibility was to use roof-top mouted PV, The location was important since the center was situated in a valley and direct sunlight was not available in most places. A 1kW roof-top mounted solar was commissioned with an MPPT Charge controller. This was connected to the Conext XW unit which diverted the energy according to the demand.