Smart Region – Smart Grid Project in Vrchlabí – automated Distribution Network
Smart Region in Vrchlabí is a project carried out by a consortium led by ČEZ Distribuce (a main DSO in the Czech Republic), it tests and assesses the advantages of use of smart grid technologies in distribution network and their utilisation for grid control, monitoring and handling of failures. The project was started in 2010, its closure and evaluation was set for 2015. Vrchlabí, a small town in the north east of the Czech Republic, was selected as a locality suitable for project implementation.
The project solution covers three use cases that contribute to the overall efficiency and reliability of power supplies in case of failures on any level of the electricity network. First two use cases deal with automated failure management on MV and LV level. Third tested area is automated island operation in defined part of Smart Region that, in case of failure on superior network, allows an independent operation. Moreover, the project tests the power quality monitoring and assessing the influence of charging of electric vehicles (EV) on the power quality.
In Vrchlabí there are also placed smart meters (for more please visit ČEZ) and one building has installed so called multi-utility measurement.
What is Smart Grid? A vision of the Smart Grid concept presents reliable, automated and efficient management of distribution network.
New smart grid technologies and functionalities lead to increased reliability and quality of power supplies to the customers and that isone of the top priorities of ČEZ Distribuce. The main reason for implementation of Smart Region project in Vrchlabí is to test and evaluate the benefits of smart grid technologies in distribution network, assess the new protection, communication and control concepts, get prepared for new trends in energy including the changes of customers behaviours (customer → prosumer – name for consumers who both consume and produce electricity) and also to lower the grid losses.
How does it work? Within the Smart Region project, CEZ Group implements up-to-date technologies in the distribution network, uses IT technologies to support network control, integrates local combined heat and power (CHP) generation units and tests electromobility.
Why here? Vrchlabí was chosen because of its size is well suited for the purpose of the demonstration project, there are renewable sources that may be integrated within the solution and it has a potential for building several CHP units. Moreover, Vrchlabí being situated near the Krkonoše Mountains National Park is an ideal location with regards to project’s environmental benefits. Last but not the least the project can be implemented thanks to the support and goodwill of the municipality.
Project is implemented in Vrchlabí town, ten thousand of inhabitants (out of 13 thousands) directly profit from the project, indirectly the entire town and the adjacent region as the project contributes to more reliable power supplies to the key infrastructure in town Vrchlabí (it covers schools, medical infrastructure, cultural and sports facilities and public services institutions).
Island Operation
Island operation implementation means within Smart Region that a part of distribution network can be operated autonomously.
The power supply during the island operation is secured by 1.6 MW combined heat and power (CHP) unit. Apart from the CHP unit and changes in distribution network and implementation of appropriate ICT infrastructure, itis essential to implement island operation automatics. This automatics enables the launch of the island operation, balancing of the electricity supply and demand and also the termination of island operation. In order to run the island operation the distribution network (MV/LV substations) was fitted with new components such as protection, control and monitoring unit (IEDs), remote terminal units (RTUs), synchronisation unit (to sync the voltage, phase and frequency before reconnection of the island operation area into the standard connection within distribution grid), remotely controlled LV feeder circuit breakers. So called critical communication (100-200 ms power components control, reaction on failure, communication among power components) is done vie fibre optic cables according to IEC 60850 protocol. Other types of communication are done either by IEC 60870-5-104 or by MODBUS.
Island operation evaluates the potential of minimisation of impacts of failures on superior/surrounding networks.
See the island operation diagram.
Outside of the combined heat and power plant
Other way to say combined heat and power (CHP) generation is cogeneration.
The CHP unit consists of a power generator which is usuallydriven by a gas combustion engine, seldom by gas or steam turbine.Unlike the traditional power plants, where the heat produced during power generation is notused, the heat from cogeneration unit is used within the local heating system, thus the CHP saves the fuel as well as the environment.
Cogeneration is a modern ecological facility which reaches almost 90% efficiency of the primary fuel usage.
There are two CHP units in the boiler room at Žižkova Street in Vrchlabí; one of them generates the heat and power for two thousands of residents at the district called Liščí Kopec also during the island operation.
See a movie about the importance and the principle of a cogeneration functioning (Maximal usage of energy)
More about cogeneration within CEZ Group.
Transformer
The output from the cogeneration unit is transmitted via the transformer to the distribution network. The output of the transformer is 2 MVA and it transforms voltage from 0.4 kV to 35 kV.
LV/MV substation
Both cogeneration units are connected to the same substation through which they are connected to the distribution system.
Hot-water pipeline
Heat energy is distributed via hot-water pipeline. The aboveground part of the hot-water pipeline is usedfor placement of MV cableswhich are laid in protective tubes.
Cogeneration unit - first floor
Control room
The control room provides control and monitoring of the cogeneration facility technology. The operator monitors both cogeneration units, their parameters and other technological equipment.
Hot-water storage tanks
Storage tanks serve as reservoirs for hot water. Each cogeneration unit uses one tank with capacity 150 m3.
Cogeneration unit – technologies and equipment
In the cogeneration facility for heat and power generationare installed two gas boilers 3,5 MWt and 2,8 MWt and two cogeneration units of the same capacity 1 560 kWe of electrical output and 1 791 kWt of thermal output. Part of each cogeneration unit is a flue gas heat exchanger used to transmit heat to water and hence increase the overall efficiency of the CHP unit. Two hot-water storage tanks each of 150 m3 capacity are also part of the facility. The operating cycle of a cogeneration unit includes cooling. The heat from cooling is distributed to customers, excess heat is taken to the hot-water storage tanks and it is used later. The temperature of water in the tanks is 90°C. Hot-water storage tanks are used to balance the disproportions between the heat generation and consumption.
The cogeneration facility provides heat for residents, connected industrial sites and the city administrative buildings. The electrical energy output is sufficient to supply majority of Vrchlabí.
Additional load – electric water boiler
To maintain the balance of the power consumption and generation during the island operation, there are 6 electric boilers installed, each with capacity 36 kW. This additional load is used to stabilize the CHP operation. Additional load of 108 kW, out of the 216 kW,isbeing connected during the island operation. This allows the elimination of abrupt changes of power consumption within a range of ± 108 kW, while preventing interruptions of power supply for customers.
Island operation automatics
Island operation automatics–is equipment that ensures balance of the whole island operation, i.e. a situation when a part of Vrchlabí is disconnected from the distribution network. The automatics ensures not only balanced operation if the island area but also a transition to and from the island operation.
The transition to island operation can be done without interruption of electricity supply. In case of island operation, the installed CHP unit supplies the customers with electricity as usual. The customers can be supplied by electricity also in case of blackout.
Cogeneration unit - motor-generator
The heart of a cogeneration unit is a set of 16-cylinder motor with a generator. A turbo engine drives the generator with an electric output of 1 560 kWe. The driving fuel is natural gas with a consumption of approx. 380 m3 / h. Capacity is 71 dm3. Technological coolers are installed to re-cool the combustion mixture.
Technology room
Technology room consists of circulation pumps for hot-water distribution, a 4 MWt heat exchanger and a hot-water treatment plant.
Back-up power source
A back-up 16 kWe diesel generator is installed in order to secure the start-up of a cogeneration unit in case of failure on surrounding distribution network during the hours when the CHP is not in the operation (black start). The start of a diesel generator is launched by the cogeneration unit control system.
Standardized gas regulation station
It regulates natural gas which enters at 300 kPa medium pressure and is reduced to 42 kPa. One line of the regulation station is operational; the other is backup. The stations have their own invoicing measurement of gas consumption.
Technology coolers and emergency coolers
Technology coolers
Each CHP unit has its own technology cooler for cooling the fuel.
Emergency coolers
Emergency coolers are prepared for use in case of island operation in situations when there is a need for power supply even at the time when there is no demand for heat.
Smokestack
The smokestack originally 80 m and now 40 m high is lined with stainless steel liners; it is usedfor smoke flue from the CHP and boilers.
Automation of MV network
Automation on MV level means automatic failure management i.e. automated failure localisation and its subsequent isolation by the automation equipment remotely controlled by the SCADA system.ČEZ Distribuce expects the highest impact of this Smart Region use case in terms of strengthening the reliability of power supplies. Within the Smart Region project following tasks were carried out: the standard network reconstruction (new cables and reconstruction of MV/LV substations), network topology change, new/smart technologies placement and set up of new ICT infrastructure. ČEZ Distribuce tests the operation of MV network in parallel, moreover the network can be divided (by so called disconnection points) into several parts. The aim is to minimize the impact of failure on MV cables by automated sequence of steps carried out by power equipment and controlled by SCADA system. The first step is to isolate the failure in disconnection section and the second step is to isolate it by disconnection of cable from the two MV/LV substations closest to the failure.
In order to manage the MV failures automatically, it was necessary not only to make the above mentioned topology change, but also to equip the network with remote controlled components (IEDs, switches, load break switches) and fault current indicators, new communication and control units (RTUs, switch routers), adjustments of SCADA system and the setup of a new communication infrastructure (fibre optic and WiMAX).
MV/LV substation on Liščí Kopec
Substations in Vrchlabí are remotely controlled, and 6 of them are "disconnection" type. Disconnection substationsare used for fast isolation of part of the distribution network affected by failure. Communication within the disconnection substations is secured via fibre optic cables; the other substations are remotely controlled via Wi-MAX. All of them are used for automation of MV network and two of them for automation on LV network. Substations are fully reconstructed and equipped with new technology which is remotely controlled from the control centre.
Communication and control section
Here the control and communication technology is installed.
ICT equipment in an AXV cabinet provides communication services within DTS with a connection to the corporate data network (switch, optic switchboard). DSO equipment (RTU ABB, router, switch) provides the communication of MV elements.
Equipment supplied by the Ormazabal Current and MEgA companies is installed for the measurement of power quality. Measured values are transmitted to data repositories for further use.
In case of power failure it is possible to operate the equipment for approximately two hours due to the back-up source in the ATQ cabinet.
MV, LV technologies part
On the left are LV switchboards equipped with remote controlled circuit breakers instead of the standardly used fuse switches. The connection and setting of circuit breaker values is displayed on a LCD display.
On the right are metal-enclosed compact MV switchboards, with a SF6 gas insulation system. Switches in the switchboard are remote controlled and fitted with an ABB control and protection system.
Transformer part
A space for placement of a distribution transformer with capacity 400 kVA, 35 / 0.4 kV.
Here you can see the functional flow diagram and visualisation of MV automation
Automation of LV network
The aim of automation on LV level is to design and test the automated failure management (localisation and isolation of failure) and thus securing reliable power supply to the customers. In order to do so, there are several changes needed – esp. in the network topology, equipment of the LV street cabinets and MV/LV substations, extension of SCADA system and ICT. A network between two MV/LV substations was selected, the network topology changed from radial to parallel (interconnected between the substations). Six LV street cabinets are equipped with remotely controlled switching and protecting components (circuit breakers and load break switches) and by units for their control and communication – RTUs. RTUs communicate via WiMAX. SCADA system was extended and tackles the monitoring as well as control of the LV network. The network operator has the supervisory role.
The automation of LV network minimises the impact of failures on LV level and thus makes the power supplies more reliable.
LV street cabinets
The upper part of the LV street cabinet is equipped bycommunication and control equipment (RTU, Wi-MAX antenna) and their back-up power supply. Lower part includescircuit breakers, load break switches, fuses and a display showing the values set oncircuit breakers and load break switches.
Here you can see the functional flow diagram and visualisation of LV automation
E-mobility
Within the E/MOBILITA project, charging stationsfor normal charging and one station for fast charging are installed in Vrchlabí. The main task within the implementation is (from DSO’s perspective) to assess the impact of charging on the power quality in the distribution network.
Each station for normal charging is equipped with two separate sockets. One of them is equipped with standard Mennekes with charging parameters 32 A/400 V, the other with a standard "home" socket with parameters 16 A / 230 V.
The station for normal charging at T. G. Masaryk Square was put into operation in September 2012 and Vrchlabí thus became the sixth city in the Czech Republic, where the E/MOBILITA ČEZ extended the network of charging stations.
The second identical station is installed in the underground garages under the T. G. Masaryk Square.
Fast charging station
The station at the Benzina petrol station is designed for fast charging.
ČEZ Distribuce evaluates the influence of EV charging process on the power quality in distribution grid. In order to measure this influence, power quality monitoring device MEg30 was installed in LV street cabinet from which the fast EV charging station is supplied. The maximum output of this fast EV charging station is 50 kW.
The fast charging station is equipped with DC connectors operating on CHAdeMO and CCS charging standards which allow for a charging process with output up to 50 kW. Also AC charging is available with a standard Mennekes connector (socket) which allows for a charging process with output up to 22 kW. With this AC charging standard, the process of charging takes 1-3 hours. The DC charging with 50 kW capacity is much faster and enables charging 80% of the accumulator capacity in 20 to 30 minutes. Input voltage is 400 V AC, 50 Hz. Output voltage 400 V AC (Mennekes) / to 500 V DC (CHAdeMO and CCS), output current 0-125 A DC depending on the type of a charged vehicle and the phase of charging (i.e. current state of battery recharging – the recharging current decreases with the increasing battery charge).
Multi-utility measurement in building
CEZ Group tests in one residential building so called multi-utility measurement. Multi-utility measurement enables to the customers to see the structure and the consumption of their household. The measurement involves all types of consumption: electricity, gas, hot and cold water. The multi-utility measurement enables two way communication between the customer and suppliers, monitoring and optimization of consumptions. For the suppliers this measurement has and advantage of remote reading of customers consumption and hence reduction of costs.
The benefits of intelligent networks for customers:
- Modernization of the distribution network consistent with the new requirements of customers as well as power generators.
- Two-way communication between the distribution network and customers.
- Monitoring of the actual power consumption using smart meters.
- Testing of unique, i.e. multi-utility measurement of household consumptions.
- Optimization of consumption management using smart meters.
- Smartmeters provide customers with running values of energy consumption. In combination with the planned wider range of energy tariffs this will mean that customers will be able to better plan their individual consumption.
There is a consumption monitoring system, for residents and building managers of the building where multiutility measurement is implemented, it contains a simple overview of consumption of hot and cold water, gas and electricity. They can set filters on high and low consumptions per month, which easily identifies any error, such as malfunctioning meter or broken appliances.
Download a booklet on the consumption monitoring system.
Consumption monitoring system.
Switching station
Switching station operates on 35 kV and is used to distribute the electric power. The station is connected via 35 kV line with HV/MV substation Vrchlabí. The area of Smart Region is supplied by four MV cable feeders.
For electricity supply the 8 field switchgearis used. Two of the fields are used for isolation of part of the network in case of island operation. First serves for connection of the MV power cable feeding the island operation area and the second for transformer of self-consumption and combi choke.Combi choke device consists of choke and transformer fitted in one container. This device is used for improving grounding parameters during island operation.
In order to reconnect the island operation area back to the distribution network without the interruption of power supply, the switching station is equipped with synchronisation unit.
Communication between terminals of the switchgears and control system, the communication protocol IEC 61850 is used. Communication is implemented via fibre optic cables.
Show room
Show room of Smart Region enables to the visitors to join the virtual touraround the project implementation sites as well as the simulation of the SCADA (illustration of real statuses of LV and MV networks).
Part of the show room is devoted to present the exhibition of used LV and MV equipment.
Power quality measurement
In order to monitor the power quality parameters, there are two types of meters installed: standard equipment for distribution network consists of MEgA monitors; part of the network tests the meters Ormazabal Current.
Power quality measurement - MEgA devices
MEgA measurement devices are placed in all MV/LV substations and in part of the LV network. Communication of those devices is done via fibre optic cables or WiMAX.
Measured data are available instantaneously after measurement and are used (besides the evaluation of the power quality) for monitoring of transformers load, depicting of the histograms of voltage and current etc.
Power quality measurement - Ormazabal Current devices
The power quality monitors from company Ormazabal Current send the measured datavia fibre optic cables. Other type of data transfer isalso tested in this case – PRIME communication between LV street cabinets and MV/LV substations via LV power cables.
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