How to create equipment for digital substations. Digital substations in Russia: the process has begun Operation of transformer substations with digital control
New technologies for the production of modern control systems have moved from the stage of scientific research and experimentation to the stage of practical use. Modern communication standards for information exchange have been developed and are being implemented. Digital protection and automation devices are widely used. There has been a significant development of hardware and software control systems. The emergence of new international standards and the development of modern information technologies open up the possibility of innovative approaches to solving the problems of automation and control of power facilities, making it possible to create a new type of substation - a digital substation (DSS). Distinctive characteristics of the DPS are: the presence of intelligent microprocessor devices built into the primary equipment, the use of local area networks for communications, a digital method for accessing information, its transmission and processing, automation of the substation and its management processes. In the future, the digital substation will be a key component of the smart grid (Smart Grid).
The term "Digital substation" is still interpreted differently by different specialists in the field of automation and control systems. In order to understand what technologies and standards apply to a digital substation, let's trace the history of the development of APCS and RPA systems. The introduction of automation systems began with the advent of telemechanics systems. Remote control devices made it possible to collect analog and discrete signals using USO modules and measuring transducers. On the basis of telemechanics systems, the first process control systems for electrical substations and power plants were developed. APCS made it possible not only to collect information, but also to process it, as well as present information in a user-friendly interface. With the advent of the first microprocessor relay protections, information from these devices also began to be integrated into automated process control systems. Gradually, the number of devices with digital interfaces increased (emergency automation, monitoring systems for power equipment, systems for monitoring the DC shield and auxiliary needs, etc.). All this information from lower-level devices was integrated into the process control system via digital interfaces. Despite the widespread use of digital technologies for building automation systems, such substations are not fully digital, since all initial information, including the status of auxiliary contacts, voltages and currents, is transmitted in the form of analog signals from the switchgear to the operational control point, where digitized separately by each lower level device. For example, the same voltage is supplied in parallel to all lower-level devices, which convert it to digital form and transfer it to the process control system. In traditional substations, different subsystems use different communication standards (protocols) and information models. For the functions of protection, measurement, accounting, quality control, individual systems of measurements and information interaction are performed, which significantly increases both the complexity of implementing an automation system at a substation and its cost.
The transition to qualitatively new automation and control systems is possible using the standards and technologies of the digital substation, which include:
1. IEC 61850 standard:
device data model;
unified description of the substation;
vertical (MMS) and horizontal (GOOSE) exchange protocols;
protocols for the transmission of instantaneous values of currents and voltages (SV);
2. digital (optical and electronic) current and voltage transformers;
3. analog multiplexers (Merging Units);
4. remote USO modules (Micro RTU);
5. intelligent electronic devices (IED).
The main feature and difference of the IEC 61850 standard from other standards is that it regulates not only the issues of information transfer between individual devices, but also the issues of formalizing the description of circuits - substation, protection, automation and measurements, device configuration. The standard provides for the possibility of using new digital measuring devices instead of traditional analog meters (current and voltage transformers). Information technologies make it possible to switch to automated design of digital substations controlled by digital integrated systems. All information communications at such substations are carried out digitally, forming a single process bus. This opens up the possibility of a fast direct exchange of information between devices, which ultimately makes it possible to reduce the number of copper cable connections and the number of devices, as well as their more compact arrangement.
STRUCTURE OF A DIGITAL SUBSTATION
Let us consider in more detail the structure of a digital substation, made in accordance with the IEC 61850 standard (Fig.). The automation system of a power facility built using the Digital Substation technology is divided into three levels:
field level (process level);
connection level;
station level.
The field level consists of:
primary sensors for collecting discrete information and transmitting control commands to switching devices (micro RTU);
primary sensors for collecting analog information (digital current and voltage transformers).
The connection level consists of intelligent electronic devices:
control and monitoring devices (connection controllers, multifunctional measuring devices, ASKUE meters, monitoring systems for transformer equipment, etc.);
relay protection terminals and local emergency automatics.
The station level consists of:
top-level servers (database server, SCADA server, remote control server, process information collection and transmission server, etc., data concentrator);
Substation personnel workstation.
From the main features of the system construction, first of all, it is necessary to single out a new “field” level, which includes innovative devices for primary information collection: remote USO, digital instrument transformers, built-in microprocessor diagnostic systems for power equipment, etc.
Digital instrument transformers transmit instantaneous voltages and currents according to the IEC 61850-9-2 protocol to bay level devices. There are two types of digital instrument transformers: optical and electronic. Optical instrument transformers are the most preferred when creating control and automation systems for a digital substation, as they use an innovative measurement principle that excludes the influence of electromagnetic interference. Electronic instrument transformers are based on traditional transformers and use specialized analog-to-digital converters.
Data from digital instrument transformers, both optical and electronic, is converted into broadcast Ethernet packets using multiplexers (Merging Units) provided by the IEC 61850-9 standard. The packets generated by the multiplexers are transmitted via the Ethernet network (process bus) to the connection level devices (controllers for APCS, RPA, PA, etc.) The sampling rate of the transmitted data is not worse than 80 points per period for RPA and PA devices and 256 points per period for APCS , AIIS KUE, etc.
Data on the position of the switching devices and other discrete information (the position of the control mode keys, the state of the heating circuits of the drives, etc.) are collected using remote USO modules installed in close proximity to the switching devices. Remote USO modules have relay outputs for controlling switching devices and are synchronized with an accuracy of at least 1 ms. Data transmission from remote USO modules is carried out via fiber-optic communication, which is part of the process bus according to the IEC 61850-8-1 (GOOSE) protocol. The transfer of control commands to switching devices is also carried out through remote USO modules using the IEC 61850-8-1 (GOOSE) protocol.
Power equipment is equipped with a set of digital sensors. There are specialized systems for monitoring transformer and gas-insulated equipment that have a digital interface for integration into process control systems without the use of discrete inputs and 4-20 mA sensors. Modern GIS are equipped with built-in digital current and voltage transformers, and control cabinets in GIS allow you to install remote USO to collect discrete signals. Installation of digital sensors in switchgear is carried out at the factory, which simplifies the design process, as well as installation and commissioning work at the facility.
Another difference is the integration of the middle (data concentrators) and upper (server and workstation) levels into one station level. This is due to the unity of data transfer protocols (IEC 61850-8-1 standard), in which the middle layer, which previously performed the work of converting information from various formats into a single format for an integrated process control system, is gradually losing its purpose. The connection level includes intelligent electronic devices that receive information from field level devices, perform logical processing of information, transmit control actions through field level devices to primary equipment, and also transmit information to the station level. These devices include connection controllers, MPRZA terminals and other multifunctional microprocessor devices.
The next difference in structure is its flexibility. Devices for a digital substation can be made according to a modular principle and allow you to combine the functions of many devices. The flexibility of building digital substations allows us to offer various solutions, taking into account the characteristics of the power facility. In the case of upgrading an existing substation without replacing power equipment, remote USO cabinets can be installed to collect and digitize primary information. At the same time, remote USOs, in addition to discrete I/O boards, will contain direct analog input boards (1/5 A), which allow collecting, digitizing and outputting data from traditional current and voltage transformers in the IEC 61850-9-2 protocol. In the future, full or partial replacement of primary equipment, including the replacement of electromagnetic transformers with optical ones, will not lead to a change in the levels of connection and substation. In the case of using GIS, it is possible to combine the functions of remote USO, Merging Unit and connection controller. Such a device is installed in the switchgear control cabinet and makes it possible to digitize all initial information (analogue or discrete), as well as perform the functions of a connection controller and backup local control functions.
With the advent of the IEC 61850 standard, a number of manufacturers have released digital substation products. At present, quite a lot of projects related to the use of the IEC 61850 standard have already been completed all over the world, showing the advantages of this technology. Unfortunately, even now, when analyzing modern solutions for a digital substation, one can notice a rather loose interpretation of the requirements of the standard, which may lead in the future to inconsistencies and problems in the integration of already modern solutions in the field of automation.
Today, Russia is actively working on the development of the Digital Substation technology. A number of pilot projects have been launched, leading Russian firms have started developing domestic products and solutions for the digital substation. In our opinion, when creating new technologies focused on a digital substation, it is necessary to strictly follow the IEC 61850 standard, not only in terms of data transfer protocols, but also in the ideology of building a system. Compliance with the requirements of the standard will make it easier to upgrade and maintain facilities based on new technologies in the future.
In 2011, leading Russian companies (NPP EKRA LLC, EnergopromAvtomatization LLC, Profotek CJSC and NIIPT OJSC) signed a general agreement on the organization of strategic cooperation in order to combine scientific, technical, engineering and commercial efforts to create a digital substations in the Russian Federation.
In accordance with IEC 61850, the developed system consists of three levels. The process bus is represented by optical transformers (ZAO Profotek) and a remote USO (microRTU) NPT Expert (LLC EnergopromAvtomatization). Connection level - microprocessor protection of NPP EKRA LLC and connection controller NPT BAY-9-2 of EnergopromAvtomatization LLC. Both devices accept analogue information according to IEC 61850-9-2 and discrete information according to IEC 61850-8-1(GOOSE). The station level is based on SCADA NPT Expert with IEC 61850-8-1(MMS) support.
As part of the joint project, a computer-aided design system for the DSS - SCADA Studio was also developed, the Ethernet network structure was worked out for various construction options, a digital substation layout was assembled and joint tests were carried out, including on a test bench at OAO NIIPT.
The operating prototype of the digital substation was presented at the Electric Networks of Russia-2011 exhibition. Implementation of a pilot project and full-scale production of digital substation equipment is scheduled for 2012. The Russian equipment for the Digital Substation has passed full-scale testing, and its compatibility according to the IEC 61850 standard with the equipment of various foreign (Omicron, SEL, GE, Siemens, etc.) and domestic (LLC Prosoft-Systems, NPP Dinamika and others) companies.
The development of our own Russian solution for a digital substation will allow not only to develop domestic production and science, but also to improve the energy security of our country. The conducted studies of technical and economic indicators allow us to conclude that the cost of a new solution in the transition to serial production will not exceed the cost of traditional solutions for building automation systems and will provide a number of technical advantages, such as:
a significant reduction in cable connections;
improving the accuracy of measurements;
ease of design, operation and maintenance;
unified data exchange platform (IEC 61850);
high noise immunity;
high fire and explosion safety and environmental friendliness;
reduction in the number of I/O modules for APCS and RPA devices, which reduces the cost of devices.
A number of other issues require additional checks and solutions. This applies to the reliability of digital systems, to issues of configuring devices at the level of substation and power interconnection, to the creation of publicly available design tools targeted at different manufacturers of microprocessor and main equipment. To ensure the required level of reliability in the framework of pilot projects, the following tasks should be solved.
1. Determination of the optimal structure of the digital substation as a whole and its individual systems.
2. Harmonization of international standards and development of domestic regulatory documentation.
3. Metrological certification of automation systems, including AISKUE systems, with the support of IEC 61850-9-2.
4. Accumulation of statistics on the reliability of digital substation equipment.
5. Accumulation of implementation and operation experience, personnel training, creation of competence centers.
At present, the mass introduction of digital substation class solutions based on IEC 61850 series standards has begun in the world, Smart Grid control technologies are being implemented, applications of automated process control systems are being put into operation. The use of the "Digital Substation" technology should allow in the future to significantly reduce the cost of designing, commissioning, operation and maintenance of energy facilities.
Alexey Danilin, Director for Automated Control Systems of SO UES OJSC, Tatyana Gorelik, Head of the APCS Department, Ph.D., Oleg Kiriyenko, Engineer, NIIPT OJSC Nikolai Doni, Head of Advanced Development Department, EKRA Research and Production Enterprise
Today there is a lot of talk about the Digital Substation technology. Once this topic was developed in Russia under the auspices of FGC UES for large substations for ultra-high voltage classes (220 kV and above), but now it can also be found at more modest facilities. Moreover, the most advanced, in terms of the use of digital technologies, are several experimental 110 kV substations, such as the Olimpiyskaya substation in Tyumenenergo. This is partly due to an attempt to reduce the cost of experimental sites, partly an attempt to reduce the damage from the possible incorrect operation of new equipment in a real power system.
At the same time, it is not always clear which substation can be considered fully digital? The very introduction of digital technologies in the energy sector began more than 20 years ago with the advent of the first microprocessor-based relay protection units, which were able to be integrated into automated control systems via digital communication channels.
But today a digital substation is usually understood as a somewhat different object.
With the release this year of the amended FSK 35-750 kV Substation Process Design Standards (dated August 25, 2017), this issue can be dealt with in more detail. I think the article will be useful not only for those interested in communication technologies, but also for simple relayers, many of whom will have to deal with similar objects in the future.
Let's start with the definitions of NTP FSK 2017 (hereinafter, excerpts from the document with explanations)
As we can see, according to the position of FGC, only those substations are digital, where equipment that supports IEC-61850 standards is used.
It should be noted that the IEC-61850 standards were originally developed for operation inside a single substation, therefore, information is sent to the control room using other protocols (usually IEC-60870-5-104), which apparently does not contradict the term “digital substation”
The most important definition in my opinion, because it contains the requirement to use optical CTs and electronic VTs, as the most advanced technologies from the IEC-61850 (SV) set. It turns out that if a substation does not contain these elements, then it cannot be considered digital. Thus, there is not a single digital substation in Russia yet, because relay protection that works only for a signal is connected to all existing OTTs and ETNs (for example, the RusHydro digital test site at the Nizhny Novgorod hydroelectric power station).
Thus, the Digital Substation is the technology of the future.
Same way. All devices must support IEC-61850-8-1 (MMS, GOOSE) communications. MMS technology is intended for exchange with upper-level devices (up to the ACS server of a specific substation), and GOOSE technology is for horizontal exchange between relay protection and automation terminals and bay controllers. Thus, discrete inputs and relays of microprocessor devices should remain in the past. Good news for those who are tired of stretching the terminals
But this is very interesting news for designers - now it is necessary not only to build, but also design digital substations in accordance with IEC-61850 standards.
In essence, this means that you should design not on paper or in AutoCAD, with subsequent transfer to paper, but immediately in digital form. Those. at the output, the designer should receive a ready task for setting up the relay protection and automation equipment in digital form (a file in the SCL description language format). This will significantly reduce the setup time, but may increase the design time. To ensure that the time for project development does not increase, it is necessary to create standard projects for each substation connection. This is what FGC UES is currently doing as part of the development of the IEC-61850 national profile.
One more point - now, in order to ensure the operability of the relay protection and automation system, it is necessary to calculate the parameters of the local area network (LAN). Those. RPA will get rid of discrete circuits, but will depend on the communication network of the substation.
All functions of the relay protection and automation system at the substation will be strictly standardized and implemented on a set of logical nodes (logical node). Read the paragraph above again - I think the demand for programmers and IT specialists will soon begin to grow in the energy sector) How are you doing with the English language and abstract thinking?
Now it will be necessary to closely monitor the information security of the substation. Standardization has a downside because viruses and other malware are written for the most popular operating systems.
“Outdated” data transfer protocols can be used, but only with a serious justification.
What conclusions can be drawn from this document?
Perhaps, this time I will not draw any conclusions because I am not an expert in these technologies.
What do you think? Will the Digital Substation go “to the masses”?
DIGITAL
SUBSTATION
DIGITAL
SUBSTATION
INTERACTIVE CONTROL OF SUBSTATION SERVICE SYSTEMS THROUGH THE TOUCH PANEL OF THE INDUSTRIAL CONTROLLER
MICROPROCESSOR TERMINALS FOR PROTECTION AND AUTOMATION, ELECTRICITY METERS SUPPORTING IEC 61850 PROTOCOLS
CONVENTIONAL CURRENT TRANSFORMERS AND VOLTAGE TRANSFORMERS TOGETHER WITH BUS INTERFACE
MEASUREMENTS, CONTROL AND SIGNALING ARE IMPLEMENTED IN A SCADA SYSTEM CONTROLLED VIA INDUSTRIAL COMPUTER WITH HMI TOUCH PANEL
What is a digital substation?
This is a substation equipped with a complex of digital devices that ensure the functioning of relay protection and automation systems, electricity metering, automatic process control systems, and emergency event registration according to the IEC 61850 protocol.
The implementation of IEC 61850 makes it possible to connect all the technological equipment of the substation with a single information network, through which not only data from the measuring devices to the RPA terminals, but also control signals are transmitted.
An exclusive solution has become available
The IEC 61850 standard is very well known in substations with supply voltage class 110kV and above, we offer a solution to apply this standard in 35kV, 10kV and 6kV classes.
Why is a digital substation necessary?
Reduce design time by 25%
Typification of circuit and functional solutions. Reducing the number of functional circuits, terminal rows in the relay compartments of cells.
Reducing the volume of installation and adjustment work by 50%
A high prefabrication solution is used. The plant performs the installation of switchgear equipment for the main and auxiliary circuits. Intercabinet communications of operating current systems are laid, automated process control systems, ASKUE are mounted. Parameterization, configuration and testing of RPA systems is carried out.
Reduce maintenance costs by 15%
The transition from scheduled maintenance on time to maintenance based on the condition of the equipment due to On-line diagnostics of the condition of the equipment. This reduces the number of trips of workers for routine maintenance.
100% operational switching is performed remotely with video monitoring of operations
Simple integration of all systems into a single digital space allows you to manage the substation safely and efficiently, as well as integrate other levels of process control systems into the system.
How it works?
DIGITAL SUBSTATION IEC 61850
The customer is supplied with 100% factory-ready digital packaged transformer substations, including all major substation systems: APCS, ASKUE and SN.
KRU "Classic" have a modern architecture and in terms of their design and operational parameters meet all modern requirements to the highest degree. Thanks to a wide grid of main circuit diagrams, a high degree of flexibility is achieved in the design and application of switchgear.
All 10 kV switchgear cells installed in the substation are equipped with an electric drive of the grounding switch and a withdrawable cassette element with a switch.
The SKP module is a special electrical container with insulation, equipped with lighting, heating and ventilation systems and electrical equipment built into it.
These modules have a high factory readiness with short installation and commissioning time, which, along with high corrosion resistance and the ability to operate in harsh climatic conditions, makes them indispensable in the construction of complete transformer substations.
■ The modular building does not require maintenance during its entire service life.
■ manufacturer gives a guarantee for anti-corrosion protection and painting for the entire service life.
■ The modular building has a heat loss capacity of no more than 4 kW in normal operation (outside temperature-40°C, inside temperature +18°C) and 3 kW in energy saving mode (outside temperature -40°C, inside temperature +5°C).
SKP modules are made of metal with an aluminum-zinc coating (Al-55%-Zn-45%), which provides guaranteed protection against corrosion for the entire service life of the modules.
How it works?
How it works?
DIGITAL SUBSTATION IEC 61850
Switchgear cabinets are equipped with microprocessor terminals for protection and automation, as well as analog-to-digital converters. The conversion of analog signals into digital ones does not go beyond one switchgear cabinet.
For the operation of the protections UROV, ZMN, AVR, LZSH, arc protection, DZT, OBR, an inter-terminal connection is required. Using the IEC 61850 protocol, all signals between terminals are transmitted over one optical cable or one Ethernet cable. Thus, the exchange between cabinets is carried out only on a digital channel, which eliminates the need for traditional circuits connecting cabinets.
The use of optical cable or Ethernet cable instead of conventional signal cables reduces the duration and cost of substation downtime during the reconstruction of secondary equipment and creates an opportunity for easy and quick reconfiguration of the protection and automation system.
Most of the discrete signals transmitted between relay protection and automation devices directly affect the rate of elimination of the emergency mode, so the signal is transmitted using the IEC 61850-8.2 puncture. (GOOSE), which is characterized by high performance.
Transmission time of one GOOSE data packet
messages does not exceed 0.001 seconds.
Was Became
The transmission of measurements and discrete signals from RPA devices to the APCS system is carried out using the MMS protocol (using buffered and unbuffered report services). During the operation of telesignaling and telemetry systems, a large amount of data is transmitted. To reduce the load on the information network, the MMS protocol is used, which is characterized by the compactness of the transmitted information.
How it works?
The IEC 61850 communication protocol enables real-time self-diagnosis of the equipment and all systems installed in the substation. In case of detection of deviations from the normal mode of operation, the system automatically activates the backup circuit, and the corresponding message is issued to the operating personnel.
The system analyzes the received data and generates recommendations for equipment maintenance, which allows you to change the principle of work from regular scheduled preventive maintenance to work upon the occurrence of malfunctions. This principle of operation makes it possible to reduce the cost of personnel for the maintenance of equipment.
Thanks to the IEC 61850 protocol with a standardized interface, when designing a substation, it is possible to use equipment from any manufacturer that supports this protocol. The DSP has the ability to be easily integrated into the upper-level process control system.
How it works?
DIGITAL SUBSTATION IEC 61850
In the digital substation ETZ Vector, full remote control of all switching devices of connections is implemented: a circuit breaker, withdrawable element, grounding switch. Thus, the complete control of the substation is carried out remotely, which significantly increases the safety of personnel.
Collection of information from the entire substation and real-time control of switching devices is carried out using the Scada-system, which is included in the basic package of all ETZ Vector digital substations.
It is planned to have an automated workplace for operational personnel at the substation and/or at the control room. The Scada system allows you to visualize the signals and events occurring in the substation and provides detailed information about the alarm or event in a graphical display.
Additionally, one of the functions of the Scada-system is the broadcast of video images from cameras installed in the compartments of cells, which allows you to monitor the status of switching devices.
Scada - the system is easily integrated with any top-level software systems, so it will not be difficult to include the substation in a single digital space of the energy district.
