Smart Grid in practise - implementation of the billaterall supply system in Gdynia trolleybus network
1) The purpose of the research.
Nowadays the issue of electric energy saving in public transport is becoming a key area of interest which is connected both with a growth in environmental awareness of the society and an increase in the prices of fuel and electricity. It can be achieved by improving the usage of regenerative breaking. In 2016 the PKT (Trolleybus Transport Company) in Gdynia began practical implementation of Smart Grid solutions within its trolleybus network. These activities constitute an element of the project 'Eliptic'', realised by PKT within the scientific research fund 'Eliptic 2020'. The first stage of implementing intelligent network solutions was completed in 2016, and further activities are planned for the next few years. The paper present the result of implementation of this technology
2) The principal results and accomplishments and their significance.
In June 2016 PKT Gdynia began practical implementation of Smart Grid technology within the exploited trolleybus system. The first stage of the task realisation was to introduce bilateral supply of the trolleybus network in two places:
A) between substations Sopot I and Sopot II
B) between substations dworzec and Grabówek
The introduction of bilateral supply resulted in the increase of recuperation effectiveness and in the reduction of energy transmission losses.The drops and fluctuations of voltage in the contact line were also significantly reduced. The obtained results confirm, to a considerable extent, the theoretical calculations and justify further realisation of the programme consisting in Smart Grid technology implementation in the trolleybus network supply system.
3) The major conclusions.
To increase the use of energy recovery, at first it is necessary to consider the possibility of reconfiguring the supply system, which will facilitate the flow of braking energy. In many situations, very good results can be achieved at a low cost. Small substation power supply areas galvanically isolated from the rest of the network should be avoided. Supply areas of such substations should be interconnected to create the largest area of recuperation energy flow.
Therefore, it is recommended to introduce bilateral supply of the overhead line to allow for an increase in the utilization rate of recuperation and reduction of transmission losses. Bilateral power supply may be used both in central and decentralized power supply systems.