SMA Inverter and Cyber Security Issues

Recently a study on cyber security threads regarding PV inverters was published, in which SMA was mentioned. The topic has also since been seized upon by other media outlets. Unfortunately, the claim has caused serious concern for SMA customers. SMA does not agree with this article, as some of the statements are not correct or greatly exaggerated.

Click HERE for the complete response by SMA.
HIER geht es zur deutschen Seite.

I hope that all vendors of network connected devices are as serious as SMA when it comes to security.

Is IEC/TR 61850-90-7 part of Edition 1, 2, or 3?

The document IEC/TR 61850-90-7:2013-02

Communication networks and systems for power utility automation
Part 90-7: Object models for power converters in distributed energy resources (DER) systems

has been published the other day.

Is this document part of IEC 61850 Edition 1, 2 or 3? NEITHER NOR!

It has its own history which starts with IEC/TR 61850-90-7 - Edition 1 - 2013-02 as you can see on the document:

When we talk about editions – be very careful and precise.

Implementing a model (Logical Node, data object, …) from IEC/TR 61850-90-7 - Edition 1 may require IEC 61850-7-3 Edition 2 or not … it depends on the model itself.

Details of Inverter-based DER Devices Modelled in IEC 61850-90-7

Functions and Information Exchanges for Inverter-based DER Devices are modeled in IEC 61850-90-7. What does this document provide? A lot of useful models for real functions needed (today and in the near future) in power distribution systems with massive renewable power fed into the grid. The main models can be found in a document published the other day (see link below).

You can find many functions described and modeled in IEC 61850-90-7, e.g., frequency-watt mode:

This frequency-watt mode addresses the issue that high frequency often is a sign of too much power in the grid, and vice versa. These extreme deviations from nominal frequency can cause grid instability, particularly if they cause significant amounts of generating equipment to trip off-line.
One method for countering this over-power problem is to reduce power in response to rising frequency (and vice versa if storage is available). Adding hysteresis provides additional flexibility for determining the active power as frequency returns toward nominal.

The IEC 61850-90-7 has been written to meet crucial needs in the power delivery system. This document has to be seen in conjunction with other standards as depicted in the UML diagram below:

 

The electrical measurements like voltage, current and frequency are defined in IEC 61850-7-4 Ed2.

Note that the conversion of almost all models into UML (Enterprise Architect) will be completed soon. The huge model will be used to maintain the models in future. This is a crucial step toward tool based standardization.

Download the models based on IEC 61850-90-7 [pdf, 1.1 MB]

IEC 61850 in Italy - SMA offers IEC 61850 Piggy-Back for PV Inverters

As you may have heard, IEC 61850 is a crucial standard for PV inverters in Italy. All requirements of the Italian CEI 0-21 standard (use of IEC 61850 is recommended – expected to be mandatory soon) will be required for new plants as of July 01, 2012.

Even for plants up to 6 kW it is required to provide an interface to the network operator!

SMA has reacted on the requirements for Italian customers … including a “… Piggy-back that will be able to receive the IEC-61850 commands to implement remote shutdown and narrow the frequency limits of the inverter.”

Read the SMA Customer information on these requirements including IEC 61850 in English / German.

Use-Cases for Distributed Photovoltaic and Storage Systems

EPRI (Electric Power Research Institute, Palo Alto, USA) has been active in the research and development of the electrical power delivery systems. Just remember the projects UCA 1.0 (Utility Communication Architecture) and UCA 2.0. Both projects have contributed to the IEC TC 57 (Power System Management) and influenced several crucial standard series like the CIM, IEC 60870-6 TASE.2 and IEC 61850.

The work on the “Utility Communication Architecture” is going on in various IEC TC 57 projects and EPRI is still contributing to this process (especially to the definition of IEC 6185-90-7 - Object models for photovoltaic, storage, and other DER inverters). A very interesting EPRI report looks into the “Uses for Distributed Photovoltaic and Storage Systems”. The report lists and discusses briefly the following use-cases:

• Energy Generation
• Local Energy Storage to Compensate for Photovoltaic Intermittency
• Use of Energy Storage for Arbitrage Benefit
• Use of Local Energy Storage to Maximize Photovoltaic Generation Value
• Energy Storage for Customer or Community Backup Power
• Energy Storage to Reduce or Limit Peak Loading on the Utility System
• Energy Storage for Load Following
• Energy Storage to Reduce Customer Peak Demand
• Energy Storage for Local Power Quality Control
• System Stabilization – Transient Watt Modulation with Line Frequency
• System Stabilization - Transient Watt Modulation with Line Voltage
• Var Production for Voltage Regulation
• Var Production for Voltage Stabilization
• Var Production for Power Factor Management
• Var Compensation for Intermittent Generation
• Connect/Disconnect from Grid – Non Islanding
• Connect/Disconnect from Grid – Islanding
• On/Off Control of PV and/or Storage Inverter
• Adjusting Maximum Generation Level
• Metering Energy from Photovoltaic or Storage Device
• State Monitoring
• Event Reporting by Exception
• Event Logging

Click HERE for the 44 page report on use cases.
Click HERE for an overview about IEC 61850-90-7.

In an up-to-date publication of the German VDI nachrichten it is reported about storage possibilities on 2011-10-28 that:

• The capacity of all German pumped-storage hydropower plants would provide power for 1 hour.
• The capacity of 42 million German cars would last for 24 hours.
• The capacity of the German oil and gas storages would last at least for 2 months.
• The storage of “Wind or PV Power” (Converting Electricity to Natural Gas) is also an option.

Click HERE for an R&D report on Converting Electricity to Natural Gas.

Whatever the energy Mix will be – there is a crucial need for information and communication systems supporting the future power delivery system!

The good news is that there is no need to develop standards for information and communication systems from scratch! There are sufficient standards available, implemented and tested so that the power industry can straight use them: IEC 60870-6 TASE.2, CIM, IEC 61850, IEC 61400-25, …

PV Power to (de)stabilize the European Power Delivery System?

One swallow does not make a summer – But 100.000 do. One PV system on a roof in the nineties did not make a smart grid based on renewable resources. But due to the growth of renewable resources like PV the power delivery system changes a lot. Usually today the PV inverters do automatically frequency disconnection.

ENTSO-E the “European Network of Transmission System Operators for Electricity” noted in a letter to Commissioner Oettinger of the European Commission that too many “swallows” are flying somehow “uncontrolled” – flying alone … not being aware what’s going on around them … not seeing the system (!):

“This letter is to brief you on a security of supply issue arising from the automatic frequency disconnection settings of installed photovoltaic (PV) panels in some European countries and to request your support in encouraging the national Regulatory authorities in impacted countries to facilitate the timely implementation of remedial actions.

Due to the interconnected nature of the transmission system until such remedial actions are implemented the synchronous Central European power system is at increased risk to significant frequency deviations of a magnitude that would generate a widespread loss of supply.

In several European countries, connection standards applicable to photovoltaic panels and other distributed generation have been or are still specifying that the panels automatically disconnect from the grid whenever the system frequency reaches 0.2 or 0.3 Hz deviations from the required normal value of 50.0 Hz.

Current information from our Member TSOs, including for example Germany and Italy, indicate that the significant growth in photovoltaics in recent years has resulted in a PV installed capacity (with such settings) approaching 25 000 MW. At these levels there is clearly a risk of an instantaneous generation loss far in excess of the 3000MW generation loss „ride-through‟ design limit for the Continental European system. …”

Click HERE for the letter from ENTSO-E [English, pdf]

Ok, what to do now? Act! There are many actions needed to get CONTROL over the system in the future system based on many distributed resources! One aspect is to change limits … but more important is the control of the power resources.

A group of IEC TC 57 WG 17 is working on a very crucial part of IEC 61850: Draft IEC 61850-90-7 TR – “Communication networks and systems for power utility automation – Part 90-7: IEC 61850 object models for photovoltaic, storage, and other DER inverters” (57/1155/DC).

Major PV inverter manufacturers and other experts have drafted the above document.

Crucial aspects covered by 90-7 (in addition to IEC 61850-7-420 – DER) are:

7. DER management functions for inverters.

7.1 Immediate control functions for inverters
7.1.1 Function INV1: connect / disconnect from grid
7.1.2 Function INV2: adjust maximum generation level up/down
7.1.3 Function INV3: adjust power factor.
7.1.4 Function INV4: request real power (charge or discharge storage)
7.1.5 Function INV5: pricing signal for charge/discharge action

7.2 Modes for volt-VAr management
7.2.1 Var management modes using volt/VAr arrays
7.2.2 Volt-VAr mode VV11: normal energy conservation mode
7.2.3 Volt-VAr mode VV12: maximum VAr support mode
7.2.4 Volt-VAr mode VV13: static inverter mode
7.2.5 Volt-VAr mode VV14: passive mode.

7.3 Modes for frequency-related behaviours
7.3.1 Frequency management modes
7.3.2 Frequency-watt mode FW21: high frequency reduces active power.
7.3.3 Frequency-watt mode FW22: constraining generating/charging by frequency (see diagram below)

7.4 Dynamic grid support during abnormally high or low voltage levels
7.4.1 Dynamic grid support mode TV31: dynamic grid support during abnormally high or low voltage levels
7.4.2 Example of dynamic grid support capabilities.

7.5 Functions for “must disconnect” and “must stay connected” zones
7.5.1 “Must disconnect” MD curve
7.5.2 “Must stay connected” MSC curve

7.6 Modes for watt-triggered behaviours
7.6.1 Watt-power factor mode WP41: feeding power controls power factor

7.7 Modes for voltage-watt management.
7.7.1 Voltage-watt mode VW51: voltage-watt management: generating by voltage
7.7.2 Voltage-watt mode VW52: voltage-watt management: charging by voltage

7.8 Modes for behaviours triggered by non-power parameters
7.8.1 Temperature mode TMP
7.8.2 Pricing signal mode PS

7.9 Setting and reporting functions
7.9.1 Establishing settings DS91: modify inverter-based DER settings
7.9.2 Event logging DS92: log alarms and events, retrieve logs
7.9.3 Reporting status DS93: selecting status points, establishing reporting mechanisms
7.9.4 Time synchronization DS94: time synchronization requirements

Example (without further explanations):

7.3.3 Frequency-watt mode FW22: constraining generating/charging by frequency:

It is expected that this part IEC 61850-90-7 is one of the crucial parts of IEC 61850 for the stability of the future power delivery systems all over.

It’s “PV summer time” – there are millions of PV inverter installed (most of them are not controlled … just “flying” around.

Please contact your national IEC TC 57 committee to get a copy of the document.

Click HERE for an interesting ENTSO-E Draft “Requirements for Grid Connection Applicable to all Generators” dated 22 March 2011

The Power Systems are quite comprehensive … and complex!

Progress in Smart Grid Deployment – Too slow?

Many people all over expect that the Electric Power Delivery system will be changed to become smarter over night. A system that has been build over a period of 20, 50, …. 100+ years cannot be changed in short time! The change is likely to occur in steps over several decades – may be for ever.

Peter Fox Penner (US consultant) has summarized what is going on in the process of change. He concludes: “… Taken together, the trends discussed here show that the smart grid is expanding and developing, even if the most successful entities and programs are surprising. More importantly, these trends illustrate the evolutionary nature of smart grid development. Arguments that the smart grid is moving too slowly underestimate the scale and complexity of rebuilding our entire grid. Utilities are tasked with deploying a complex series of infrastructure investments that must work in harmony with their current (already smart) systems, use innovative pricing that customers support, and produce a net benefit. Under these conditions, slow and steady wins the race. We can expect smart grid development to occur in stages over decades, ultimately transforming the power industry into a very different business.”

Click HERE for his report in the IEEE Smart Grid Newsletter.

When we talk about the pace of change in the information technology in industrial automation we should not get nervous when we see the slow progress! How long did it take to get Gigabit/s Ethernet for substation environments developed … and accepted!? New approaches in Automation take often decades before they are accepted and used.

Click HERE for a brief discussion on Ethernet and Tokenbus … written decades ago.

The future for standards is quite bright. When a utility decides to deploy information technology for the next 10 or 20 years it will likely chose a stable standard – so that there is no need to change the solution every 4 or 5 years … when manufacturers have developed a new solution.

MMS (Manufacturing Message Specification, ISO 9506, used in IEC 61850-8-1 to define the message encoding) has been developed in the late eighties (80s !) – some 25 years ago. Web services are understood by some people as an option for messaging – more up-to-date. I have seen a Report message of a simple state change message using IEC 61400-25-2 Web Services the other day. The length of the XML coded Report message was some 850 octets !! A Report message encoded with MMS/ASN.1 BER (as per IEC 61850-8-1) is really shorter: by a factor of about 10 !!

Don’t hurry. Take your time. Rome hasn’t be built over night!

I usually sate in my seminars that the deployment of IEC 61850 happens too fast – users often do not have any clue what they got installed. They got it because it was cheaper than xyz. All in a sudden they have several substations with hundreds of IEDs communicating with IEC 61850 – and many (may be almost all) utility engineers have to struggle with this new way to do protection and automation. Many of them have started to get training in IEC 61850 … and you?

Don’t start slow and slow down fast ;-)

Just start – there is something to learn!