Thursday, July 18, 2019

VDE-Studie "Lösungsansatz für Zellulares Energiesystem"

In dem neuen Papier „Zellulares Energiesystem“ zeigt jetzt der Technologieverband VDE eine effiziente und konsensfähige Lösung für eine erfolgreiche Umsetzung der Energiewende: Die VDE-Experten empfehlen den Strom direkt dort zu verbrauchen, wo er erzeugt wird, nämlich auf lokaler und regionaler Versorgungsebene. Bei diesem „zellularen Ansatz“ erfolgt die Umsetzung der dezentralen Energieversorgung auf Basis zellularer Strukturen.

Hier zum kostenlosen Download der Studie clicken.

Die Studie verdient vollen Respekt! Der holistische Ansatz verbindet viele der bisher versprengten, wenig aufeinander abgestimmten Lösungen zu einem ganz Neuen (dem zellularen Ansatz). Herzlichen Glückwunsch!

Der zellulare Ansatz wirkt teilweise futuristisch ... man darf natürlich auch mal träumen! Konkrete Leitlinien für einen Teil der Bürger unserer Gesellschaft sind allerdings rar und insbesondere der Aspekt der „überlebensdienlichen“ Notwendigkeiten scheinen etwas unterbelichtet zu sein. So heißt es auf Seite 26 : „Der Inselnetzbetrieb im zellularen Energiesystem soll nur im Notfall eine Option sein. Im Normalfall sind der Verbundbetrieb und die Solidarität die Regel.“

Es müssen unbedingt „überlebensdienliche“ Lösungen in Form von kleinen (vorübergehend) autarken, kostengünstigen Systemen (beispielsweise PV-System mit ein paar kWp, einem Batteriewechselrichter und ein paar Batterien) implementiert werden, um im wirklich großen oder kleinen Notfall Überlebenschancen für viele – besonders für Schwache – zu bieten.

Hintergrund für diese Position:

Meine Frau benötigt 24/7 ununterbrochene nicht-invasive Beatmung durch zwei Geräte mit jeweils 4-h-Akku Notfallversorgung. Ein Gerät für den Tag und eines für die Nacht. Ein 10-stündiger Stromausfall würde wahrscheinlich ... unvorstellbar.

Beatmungsgeräte für invasive beziehungsweise nicht-invasive Beatmung sind zig-tausendfach im Einsatz! Manche gehen von mehreren 100.000 aus!

Auf der anderen Seite haben wir eine netzgekoppelte PV-Anlage mit knapp 10 kWp ... soweit so gut. Die nützt uns im Notfall nicht, weil sie nur mit dem öffentlichen Netz zusammen funktioniert.

Bei einem Netzsaufall würden unsere PV-Module nutzlos auf dem Dach liegen und sich „sonnen“ ohne einen Sonnenbrand zu bekommen ... sie würden allerdings weiter Schutz für nistende Tauben bieten.

Momentan überlegen wir, wie wir die Module im Notfall manuell auf einen Batterie-Wechselrichter umschalten könnten. Das würde helfen, einen Teil der für Notfälle benötigte Energie vom Dach zu ernsten ... der Salat und die Tomaten im Garten würden ohnehin auch ohne Strom wachsen. Wasser können wir per Handpumpe aus dem Rheingraben pumpen.

Wir alle sollten mal überlegen, wie wir diese oder eine ähnliche Notfalllösung unter die Leute bringen könnten ... das wäre zwar nicht netzdienlich – aber auf jeden Fall auch gemeinschaftsdienlich! Geladene Batterien und mobile Inverter könnten auch an die Nachbarn oder ... ausgeliehen werden.

In unserem Fall haben wir zwei Notstromaggregate, Benzinvorräte und ein paar Bleiakkus mit zugehörigen Invertern. Für den Notfall würde ich gerne einfach einen Teil der Module manuell auf einen Batteriewechselrichter (vielleicht 2 kWp) umschalten. Wenn das Netz wieder verfügbar ist, dann kann man wieder zurückschalten.

Noch eine kleine Nebenbemerkung zum Thema IEC 61850 auf Seite 38:

„Für die Kommunikation und das Datenmanagement im Prozessnetz haben sich in den letzten Jahren
u.a. die IKT-Standards IEC 60870 (Datenmodelle für Energiemanagement) und IEC 61850 (Kommunikation) etabliert.“

Hier wurden offensichtlich die beiden Normen verwechselt! IEC 61850 bietet Datenmodelle ... u.v.a. mehr und IEC 60870 bietet nur Kommunikation.

Beim Thema „Kommunikationsstandard“ haben wir mittlerweile mit den vielen neuen Ansätzen bei IEC 61850 eine hinreichende Basis, um die meisten notwendigen Informationsaustauschmechanismen ((Funktions)Modelle, Dienste und Protokolle) implementieren zu können. DER-Modelle (61850-7-420) werden zurzeit beispielsweise am KIT bei der Realisierung mehrerer Forschungsprojekte verwendet ... das sind erfolgsversprechende Ansätze!

Ich würde mich freuen, wenn der Aspekt „überlebensdienlich“ im hier beschriebenen Usecase in Zukunft in einfache technische und sinnvolle Lösungen einen zielführenden Niederschlag finden würde!

Dieser Vorschlag, den ich einigen Experten aus dem VDE-Umfeld vorgestellt habe, hat bereits nach zwei Tagen viele positive Rückmeldungen bewirkt!

Wednesday, July 17, 2019

How to ring the front door bell in case of power outage?

Today I had a phone call with a friend discussing what happens when we suffer a blackout. I was sitting in my home office in the basement when the door bell was ringing. I asked my friend: What would happen, when we would have a power outage here at home?

He sent me a nice picture that I used as an instruction to install a very useful (new) SuperCat bell push at our front door:




If you push the left button ... Auuuuutsch ... we would hear you crying ... haha.

Nice blackout-resisting door bell. I have removed it later ;-)

Thursday, July 11, 2019

Holistic Engineering and IEC Standards


One of the most crucial challenges in Electric Power Systems in the future is the fact that multiple aspects like planning, design, configuration, data acquisition, operation, protection, error detection, maintenance, ... security, ... at several layers (process, asset management, ...) are so co-joined with each other and interdependent.

Is this new? No! Some 400 years (!) ago, Rene Descartes was recommending to apply a holistic approach for all sciences ... he did not know the huge interconnected Power systems in Europe, China, USA, ... here is what he has written [extended by myself]:



I highly recommend to educate young people in a way that they get a holistic understanding of the many aspects of the electric power system ... focusing on one or two aspects may cause at the end of the day many problems. The main aspect still is to understand the physics of such a huge system. Any programmer of software impacting the safety of the power delivery system should be educated in physics and especially electrical systems. So, understanding MMS, IEC 61850 or OPC UA is good - BUT engineers should understand the process (electrical system) they are manipulating with some lines of code. Engineers should also be trained thoroughly in the many aspects.

Unfortunately there is quite often little budget for comprehensive training in several aspects. Ask your management for more training - better:more hands-on training!!

Friday, July 5, 2019

IEC 61850-8-2 Versus IEC 61850-8-1

Many people have complained that IEC 61850 is far too complex ... especially because of the mapping defined in IEC 61850-8-1 as the SCSM (Specific Communication Service Mapping) using ISO 9506 MMS as the carrier to exchange IEC 61850 client/server messages. MMS (Manufacturing Message Specification) offers generic objects (NamedVariables, NamedVariableLists, ...) and services (Read, Write, InformationReport, ...). The application of MMS for IEC 61850 requires to define very tricky mappings ...

Click HERE for downloading the FDIS of ISO 9506-1.
Click HERE for downloading the FDIS of ISO 9506-2.

As the convenor of ISO TC 184/SC WG2 (responsible for MMS for many years) I have supported MMS allover ... and I still do it. It is a solution that works well for years ... especially in the domain of substation automation. Other application domains, e.g., DER devices connected directly to a control center (without the need of horizontal communication with up to hundreds of devices), could make use of a lighter message service and mapping concept. The idea of using webservices was discussed many years ago. The IEC TC 57 set up a team to look into it.

The following document written in 2012 discusses the:

IEC 61850-8-2 Web Services Justification

Excerpt:
"IEC 61850/MMS is an open scalable suite of protocols that can support real-time operation. However, these protocols are not well understood by typical IT professionals that work in these stakeholder environments, even though the rich information models of IEC 61850 meets the semantic needs of the distributed applications. ...
Therefore it makes economic sense to map the rich abstract IEC 61850 information models to the more ubiquitously deployed and understood communication and security profiles.   This requirement can be satisfied by mapping IEC 61850 to web services, which are the most commonly implemented technologies.
IEC 61850/Web Services is not a replacement for MMS used in the substation.  Rather, IEC 61850/Web Services would be targeted to customer environments where information is used to interact with customer-owned equipment, including Distributed Energy Resources (DER) systems and facility energy management systems. In these situations, information flows between utility systems, customer systems, and third party systems, straddling utility and customer ownership, sometimes within a single application deployment.
The stakeholders deploying DER systems understand that IEC 61850 over web services provide least cost protocols to interact with their DER devices because:
Web Services provide greater compatibility with widely deployed IT infrastructures, tools and skills, including cyber security.
..."

Finally the work ended in the following standard:

Communication networks and systems for power utility automation – Part 8-2: Specific communication service mapping (SCSM) – Mapping to Extensible Messaging Presence Protocol (XMPP)

The published document 8-2 uses principles of IEC 61850-8-1 as well as MMS services and protocols! Really? Yes. The main difference regarding message exchange is in the encoding of the MMS messages: 8-1 uses ASN.1 BER and 8-2 uses XML messages (with the structure of MMS services defined as XML Schema). Strange? Yes!

You can find the XML schema for the MMS messages using XML encoding here:

Code component of the IEC 61850-8-2, reflecting the XML namespace described in this document. It includes as well the virtual API with IEC 62351-4.

https://www.iec.ch/public/tc57/IEC_61850-8-2.2018_ed1.0.XSD.2018A1.full.zip

Summary on the protocol issues: IEC 61850-8-2 does NOT provide a direct mapping of IEC 61850-7-2 ACSI models and services to webservices!

I am involved in defining a third mapping (of a subset of services) ... to use JSON schema (and objects) for the models and the messages ... in order to offer really light weight messaging carrying a subset the original semantic of IEC 61850 models!!

We have successfully implemented client and server using http Get and Set services that carry JSON objects representing IEC 61850 Objects.

Example of DataSet and Report (showing the basic idea of mapping to JSON):



The decision to propose the JSON mapping officially to IEC TC 57 is expected later in 2019.

By the way, our granddaughter (20, Student in EE and IT) has implemented this example in Python running on Windows and on two Raspberry Pi3 (one playing the role of server and the other one as client).

We expect that this mapping will push the application of IEC 61850 models and services in domains that need simple solutions that can be programmed by many engineers and programmers.

The JSON mapping could easily be used as an interface from an original IEC 61850 Server (e.g., a bay controller or protection device) to underlying systems:



Sample JSON response from our Fronius PV Inverter with some values:

Request:
http://192..../solar_api/v1/GetInverterRealtimeData.cgi?Scope=Device&DeviceId=1&DataCollection=CommonInverterData

Response (JavaScript):



Stay tuned to learn more ...

Tuesday, July 2, 2019

1 MWh Electric Energy May Cost 37.856 Euro - You Don't believe it?

Belief me, this is true: You could have sold 1 MWh electric power to the German Grid for 37.856 Euro the other day (used for primary frequency control) - if you would have had the opportunity to sell it on the spot market ...

We have our roof PV system some 10 kWp since Sept 2016. The energy produced since then is 25 MWh ... this would sum up to 25 x 37.856 Euro = 946.400 Euro !! WOW !! Unfortunately I did not have the opportunity to influence the German electricity market and to make such a sale ...

See some news in German regarding the situation.

Something went wrong on the 6., 12. and 25. June 2019.

The belief in the Market to fix everything ... may end up in a big blackout.

Add-On (2019-07-03):

Today I found more details on the reasons why we were so close to big trouble:

"Due to a faulty data package, the European electricity
exchange EPEX in Paris decoupled the European
electricity market on June 7, 2019. This caused a great
deal of excitement on the markets. Johannes Päffgen,
Head of Energy Trading at Next Kraftwerke, explains the
causes and consequences in an interview.
Christian Sperling: Johannes - What happened? Why
was there so much trouble at EPEX on the Friday before
the Whitsun holidays?
Johannes Päffgen: Well - in the end it's a computer error... but we should go into that later. At about 11:40 this Friday we noticed that something was wrong at EPEX. We couldn't place any more bids for the day-ahead electricity auction on Saturday. ..."

Clicke HERE for the full report.

I guess it was a human error ... somebody didn't take into account that corrupted data packages will be sent and received ... how could a faulty package have such a dangerous result?!?!

Unbelievable.

Stay tuned for more information once available.

Monday, July 1, 2019

IEC TC 57 Just Published Amendment 1 of FDIS of IEC 61850-9-2

The following FDIS has been published last week:
57/2112/FDIS

Amendment 1 – Communication networks and systems for power utility automation – Part 9-2: Specific communication service mapping (SCSM) – Sampled values over ISO/IEC 8802-3

The ballot closes: 2019-08-09

Compared to the second edition, this first revision of the second edition:

a) updates the normative references
b) adds a synchronization clause (Clause 9); adds references to IEC 61588:2009 and
IEC/IEEE 61850-9-3 for SV synchronization;
c) modifies physical layer specification in T-Profile;
d) modifies MSVCB components (Table 9 and Table 10);
e) deprecates usage of USVCB;
f) modifies encoding for the transmission of the sampled value buffer (Table 14);
g) adds Table 20;
h) adds Table 21;
i) adds Annex C related to possible backward compatibility issues between revisions of this
standard;
j) provides clarifications and corrections to the second edition of IEC 61850-9-2, based on the
tissues = { 1349, 1272, 1055, 944, 863 }.