WO2020025586A1

WO2020025586A1 - Method for monitoring compliance with feed-in conditions

Info

Publication number: WO2020025586A1
Application number: PCT/EP2019/070443
Authority: WO
Inventors: Oliver Mews; Leander Rust; Stefan Vetter; Marcus Vorpahl
Original assignee: Senvion Gmbh
Priority date: 2018-07-30
Filing date: 2019-07-30
Publication date: 2020-02-06
Also published as: DE102018005967A1

Abstract

The invention relates to a method for monitoring compliance with feed-in conditions and an arrangement (1) designed for said purpose and a corresponding set of computer program products. The method monitors compliance with feed-in conditions for an electrical grid (1) by one or more energy generation units (4, 5) feeding power into said grid by means of the steps: –detecting the voltage and current strength per phase at the grid feed-in point of an energy generation unit (4, 5) or a group (6) of energy generation units (5) to form time series of measured values; –calculating hash values for time series of measured values; –determining evaluation variables from time series of measured values; –adding the hash values and evaluation variables to a distributed-ledger database; –verifying the compliance of feed-in conditions on the basis of the evaluation variables in the distributed-ledger database by a computer protocol (16) mapping the feed-in conditions.

Description

Compliance monitoring procedures

feeding conditions

The invention relates to a method for monitoring compliance with feed-in conditions and to an arrangement designed for this purpose and a corresponding set of computer program products.

With the advent of the use of regenerative energies, such as wind and sun, the operation of energy networks for the distribution of the electrical energy generated and fed into it has changed. Whereas in the past only a few conventional power plants fed the required energy into an energy network at a few points, whereby the operation of the power plants and the network was often in one hand, nowadays an energy network is used in many places - the original often not for it were envisaged - energy was fed into the energy network from energy generation units that were regularly small in comparison to conventional power plants, although the operators of the energy generation units generally did not also operate the energy network. These energy generation units can be, for example, photovoltaic systems, a single wind energy system or wind energy systems combined to form a wind farm.

The operator of the energy network is responsible for the availability and stability of the energy network. In order to achieve this, he can define conditions that the operators of energy generation units have to meet in order to be able to feed energy into the energy network. These feed-in conditions, which are often referred to as “grid codes”, can determine in what way and / or to what extent the energy generation units must contribute to grid stability, how they must behave in the event of a fault in the grid and / or which external control commands by the operator of the energy supply network in which time must be implemented. Smaller disruptions in the network can generally be quickly compensated for in such a way that the stability of the network is generally preserved and no problems are to be expected, in particular, for the consumers connected to the network. If there is a major disturbance in the network, for example a voltage dip, a voltage increase, a frequency deviation, etc., which cannot be compensated for in the short term, this can lead to problems for consumers, but also for the components of the energy network itself. which can range from a short-term failure to damage or destruction of the consumers or energy network components. In these cases, a detailed research into the causes of the cause of the fault is carried out - also on the basis of any claims for damages, whereby in this context the accusation may arise that an energy generation unit is causing the fault or at least does not conform to the fault regarding the feed-in conditions.

In these cases, an expert is often called in, who tries to clarify compliance with the feed-in conditions at the time of the fault on the basis of data recorded by the energy generation unit and / or the energy supply network.

A disadvantage of this state of the art is the complex, lengthy and generally cost-intensive analysis by an expert. Another disadvantage is that the corresponding expert reports are then only regularly requested and prepared if a massive violation of the feed-in conditions is suspected or if damage has actually occurred. A breach of the feed-in conditions that is not significant in the case of smaller faults, but which can lead to damage in the case of larger faults, often remains undetected.

The object of the present invention is to create a method, an arrangement and a set of computer program products for monitoring the compliance with feed conditions, in which the disadvantages known from the prior art no longer occur or only to a reduced extent. This object is achieved by a method according to the main claim, an arrangement according to claim 9 and a set of computer program product according to claim 10. Advantageous further developments are the subject of the dependent claims.

Accordingly, the invention relates to a method for monitoring compliance with the feed-in conditions of a power grid by one or more energy generation units feeding therein, with the steps:

Detection of the voltage and current per phase at the grid feed-in point of an energy generation unit or a group of energy generation units to form measured value time series;

Calculating hash values for measurement time series; Determination of evaluation variables from measured value time series;

Adding the hash values and evaluation values to a distributed ledger database; and

Checking compliance with the feed-in conditions on the basis of the evaluation variables in the distributed ledger database by means of a computer log depicting the feed-in conditions.

Furthermore, the invention relates to an arrangement comprising at least one energy generation unit which feeds into a power grid at a grid feed-in point, a detection module for detecting the voltage and current strength per phase being provided at the grid feed-in point and the components of the arrangement for carrying out the process according to the invention Procedure is formed.

The invention also relates to a set of computer program products, comprising program parts which, when loaded into a computer or into computers networked with one another, are designed to carry out the method according to the invention. The invention has recognized that through detailed monitoring of the power fed in by a power generation unit or a group comprising a plurality of power generation units at a network feed-in point and a manipulation-safe processing of the measured values based on this, reliable and reliable for the respective operator of power generation units and power grid extremely transparent determination of compliance with the feed-in conditions, a significantly simplified processing in the event of losses or damage due to deviations from the feed-in conditions is possible.

The automation of the monitoring provided according to the invention also makes it possible to determine non-compliance with the feed-in conditions in the case of less critical network faults, in order to be able to remedy any malfunctions of the energy generation unit. The basis for the method according to the invention is the detection of the voltage and current strength per phase at the grid feed-in point of an energy generation unit or a group of energy generation units. In principle, these measured values can be recorded by suitable measuring devices of the energy generating unit itself, which are provided for control purposes. However, since these measured values are the basis for the later determination of compliance with the feed-in conditions and must be regarded as trustworthy by the parties involved, it is - especially if on the part of of the power grid there are no suitable measuring devices for validating the measured values recorded by the energy generation unit - preferably if the voltage and current intensity per phase at the grid feed-in point is recorded by a calibrated and / or lead-sealed detection module. The acquisition module can in particular be made available and operated by a jointly selected third party, so that the operators of the energy generation unit (s) and of the power grid trust the acquired measurement values.

The measured values result from the measured value time series, that is to say a time-dependent sequence of measured values which reflects the course of the measured variable. The measured value time series can have a fixed predetermined length and can be strung together in such a way that they provide a continuous image of one or more measured values when strung together.

Also, in order to keep the calculation and storage effort, which will be explained in more detail below, as low as possible, it is preferred if a measured value time series is only formed when a network fault signal is present, preferably for the duration of the presence of the network fault signal. In other words, an actual measurement time series, which is subsequently processed further, is only created if there is actually a fault in the network and this is indicated by a network fault signal. The network fault signal can be transmitted directly by the operator or the control center of the power grid, or the power generation unit or a detection module for detecting the voltage and current per phase at the grid feed-in point have means for detecting a grid fault based on the measured values and for generating a corresponding grid fault. signal.

In order not only to record the feed-in behavior of the energy generation unit (s) immediately when a network fault signal is present, but also to record a defined period before and / or afterwards, it is further preferred if the measured value time series is supplemented by measured values that precede a predetermined period and / or have been or are detected after a fault signal is present. In particular, since there is a certain delay between the actual occurrence of a network fault and the presence of a network fault signal, supplementing the measurement time series with measured values before the actual presence of the fault signal can ensure that both the moment of the fault occurrence and the feed-in are recorded in the measured value time series before the fault occurs. If the measured value time series is recorded by measured values for a period after the power failure signal has ceased, the return of the energy generation unit (s) to the normal feed-in can also be recorded.

A hash value is calculated for each measurement time series - whether created continuously or only when required. A hash value is the result of a non-injective, preferably cryptographic, scatter value function, with which a fingerprint of the measured value time series that is as clear as possible is created. If necessary and / or desired, the measurement time series can be saved and archived separately from the hash values using a corresponding hash value. Subsequent changes to a stored or archived measurement time series would lead to a different hash value when recalculated, with which manipulations of the measurement time series can be detected.

The hash values for measured value time series can be calculated by the acquisition module that acquires the measured values. However, it is also possible for this module to make the measured values and / or measured value time series available to an external entity, which then calculates the hash values. In particular, it is possible for more than one instance to carry out the hash value calculation, the calculated hash values then being mutually validated. For example. the hash value calculation can be carried out both by a computer of the operator of the energy generation unit (s) and by a computer of the network operator. Evaluation values are also determined from the measured value time series, on the basis of which compliance with the feed-in conditions can be checked. A possible evaluation parameter is, for example, the active power rate - that is, the change in the active power fed in over time - after a network fault that caused a voltage breakdown has been remedied. In addition, compliance with characteristic curves and operating ranges, as specified by the feed-in conditions (for example with regard to the reactive current dynamics and the active power reduction when increasing the frequency), can be checked. It can also be checked whether the power generation unit switches off in good time in the event of significant network faults and / or whether minor network faults occur properly. Comparable to the hash values, the assessment parameters can be determined by the acquisition module for the measured values. Here too, however, it is possible for the evaluation parameters to be carried out and mutually validated by several entities, for example the operator of the wind energy installation (s) and / or the power grid. The calculated hash values of a measured value time series and the determined evaluation variables of the same measured value time series - but not the measured values of the measured value time series itself for reasons of storage space - are then added as a data record to a distributed ledger database. Distributed ledger databases are databases that are managed locally on networked computers and come to an agreement (consensus) on the sequence of database entries and changes. An example of such a distributed ledger database is the blockchain. A blockchain is a continuously expandable list of data records that are linked to one another in a tamper-proof manner using cryptographic methods. Each data record typically includes a cryptographically secure scatter value of one or more previous data records, a time stamp and the actual user data, in this case hash value and evaluation variables. The blockchain can also be managed and stored decentrally, which can further increase its security.

The use of the well-known distributed ledger technology, in particular blockchain technology, ensures that the hash values and evaluation variables can no longer be manipulated afterwards.

When the hash values and evaluation variables are added to the distributed ledger database or blockchain, a computer protocol depicting the feed-in conditions is preferably used at the same time to check whether the feed-in conditions have been complied with on the basis of the evaluation variables added or to be added to the distributed ledger database or blockchain , It is of course also possible for the check to be carried out before or after adding the hash values and evaluation variables. However, the check at the same time as the addition can be achieved directly using known smart contract technologies, which are considered to be tamper-proof, so that generally no additional tamper-evident precautions need to be taken when checking compliance with the feed-in conditions, as is the case with a separate one - or downstream review could be the case.

The result of the check is preferably also stored in the distributed ledger database or blockchain and is therefore tamper-proof. In particular, if a smart contract technology is used, it is possible to save the result of the check directly together with the underlying evaluation parameters and the associated hash value in a single data record. The method according to the invention offers a tamper-proof verifiability of the compliance with the feed-in conditions of a power grid by one or more power generation units feeding into it, in particular in the event of grid faults. It is only conceivable and possible that the operators of power generation unit (s) and / or power grids trust the final result of the method to such an extent that one or more experts usually check the feed-in behavior by an expert examination of the feed-in behavior Power generation units can be dispensed with in the event of a grid failure.

If a corresponding expert opinion is nevertheless requested, it can be checked on the basis of the hash value calculated and stored according to the invention that the operator is actually presented with the correct measured values recorded by the operators at a predetermined point in time, for example a network fault. Even in this case, the method according to the invention thus offers even greater security against manipulation.

In principle, it is also possible, for example, to monetarily reward compliance with the feed-in conditions or special requirements of the network operator. If this can be derived from the evaluation parameters, the reward can also be shown automatically in the form of a smart contract.

Since, according to the invention, the measured values at the grid feed-in point are used, in particular in the case of wind energy plants which are combined to form a wind farm, additional devices which are integrated into a wind farm internal grid and can influence the feed-in of energy, such as STATCOMs or energy stores, also recorded with transparency. In other words, it is fundamentally irrelevant for checking compliance with the feed-in conditions, which devices are arranged behind the grid feed-in point and are actually active. In order that the determination of evaluation variables and the subsequent check of compliance with the feed-in conditions can be carried out with sufficient accuracy and reliability, it is preferred if the voltage and current strength per phase are recorded at a sampling rate of at least 1 kHz, preferably at least 2 kHz. further preferably takes place of at least 5 kHz. It has been shown that with appropriate sampling rates, a sufficiently precise picture of the actual situation at the grid entry point can be provided. To explain the arrangement according to the invention and the set of computer program products according to the invention, reference is made to the above explanations.

The use of a set of computer program products shows that the individual computer program products in the set can be executed on different computers. This enables efficient resource distribution and use, especially if the computer program products are not exclusively executed on a computer.

The energy generation units are preferably wind turbines. A group of corresponding energy generation units is a wind farm. The invention will now be described by way of example with reference to an advantageous embodiment with reference to the accompanying drawings. It shows:

FIG. 1: an arrangement according to the invention designed to carry out a method according to the invention.

An arrangement 100 according to the invention is shown in FIG. The arrangement comprises a power network 1 comprising a local transmission network 2 and a number of local distribution networks 3 connected to it. In particular, various consumers (not shown), such as industrial companies, commercial enterprises and households, are connected to the distribution networks 3.

The energy to be distributed through the power grid is provided by energy generation units 4, 5. In addition to a conventional power plant 4, which feeds the generated energy directly into the transmission network 2, individual wind energy plants 5 or those combined in a wind farm 6 also feed energy into the power grid 1. Among others Due to the spatial proximity of the respective lines, the feed often does not take place in the transmission network 2, but rather in local distribution networks 3. In the exemplary embodiment shown, the wind farm 6 also includes an energy store 7, which together with the wind energy plants 5 via a network 8 internal to the wind farm Transformer and park control station 9 is connected to the power network 7, in particular a local distribution network 3.

The power grid 1 is monitored in a network monitoring and control center 10 using measuring stations and sensors (not shown). The network monitoring and control Central 10 is connected via data lines 11 directly or via a park control station 9 to the individual energy generation units 4, 5, and can make these specifications regarding the energy feeds that are either implemented directly by energy generation units 4, 5 or initially by one Park control station 9 can be translated into individual specifications for the wind energy plants 5 connected to them and the power store 7.

The obligation of the energy generation units 4, 5 to react to corresponding specifications within a certain time is laid down in the feed-in conditions. These feed-in conditions also contain provisions for the behavior of the energy generation units 4, 5 in the event of a grid failure, which must be implemented by the energy generation units 4, 5 even without an explicit separate specification.

To check whether the wind energy installation 5 or the wind farm 6, comprising a plurality of wind energy installations 5 and a power storage unit 7, comply with the feed-in conditions, detection modules 12 are provided at the respective grid feed-in points, with which the voltage and current intensity are recorded separately for each phase with a sampling rate of 5 kHz becomes. The detection modules 12 are designed to use the measured values to detect network faults, for example due to a sudden massive voltage drop, and then to generate a network fault signal. Optionally, as shown for the wind farm 6, the acquisition modules 12 can also be connected to the network monitoring and control center 10 via a data line 11 in order to receive any network fault signals from there.

If a self-generated network fault signal or a network fault signal originating from an external source is present in a detection module 12, the measured values currently recorded are combined in a measured value time series. These are supplemented by the measurement values of the last 10 seconds before the input of the network fault signal stored in a buffer of the acquisition module 12. The measured value time series is updated by 5 seconds until the network fault signal disappears and beyond. This ensures that not only the feed-in behavior during the presence of a grid fault signal, but also the feed-in before the occurrence of the grid fault and after its clarification, including the respective transients, is recorded in the measured value time series.

The measurement time series created in this way can, if required, be stored and archived in a data memory optionally connected to the acquisition module 12 for later checking. In any case, however, they will be transmitted via data lines 13 secured by encryption transmitted to a computer network 14. The computer system 14 is a plurality of computers which each execute the functions described below in parallel and then validate their results with each other. In particular if the computers of the computer network 14 are assigned to different operators, it can be ensured in this way that the computers are not manipulated with regard to the interests of individuals.

In the computer network 14, hash values for measured value time series are calculated, with the aid of which it can be determined at a later point in time with a high degree of certainty whether an archived measured value series corresponds to the measured value series on which the hash value calculation was based.

Furthermore, 14 evaluation variables for measured value time series are determined in the computer network. The evaluation parameters are selected in such a way that they can be subsequently checked for compliance with the feed-in conditions. In the present example, also for the sake of clarity, only one evaluation variable is calculated, namely the active power rate after clarification of a grid failure resulting in a voltage breakdown. However, it is of course possible and also regularly displayed to calculate a large number of evaluation variables.

If the hash value calculation and the determination of the evaluation variables have been completed and the validation by the individual computers of the computer network 14 has been positive, the hash values and calculation variables - but not the measured value series - are transmitted to a database network 15 which operates according to the blockchain principle. Similar to the computer network 14, it is not a singular database that is provided, but rather a plurality of databases that are synchronized with one another in a network, so that - particularly if the individual databases in the network are assigned to different operators - there is a high level of security against manipulation.

When adding the hash value and the associated evaluation parameters, compliance with the feed-in conditions is checked based on the evaluation parameters based on the principle of a smart contract. For this purpose, the feed-in conditions are shown in a computer protocol 16, which can carry out the corresponding check for individual conditions and / or all conditions together on the basis of the evaluation variables. The calculated hash value, the associated evaluation variables and the verification of compliance with the feed-in conditions based thereon are added to the database of the database system 15 as a new data record.

The database or the newly added data record has the following structure:

Due to the blockchain technology used according to the invention, subsequent modification or manipulation, but also deletion of the data is practically impossible.

The data stored in the database system 15 can be accessed at any later time by any party, the access being able to be regulated in a known manner via access rights, so that only authorized persons can actually see the data.

Claims

claims

1. A method for monitoring compliance with the feed-in conditions of a power grid (1) by one or more power generation units (4, 5) feeding therein, comprising the steps: - Detecting the voltage and current strength per phase at the grid feed-in point

Energy generation unit (4, 5) or a group (6) of energy generation units (5) for forming measured value time series;

Calculating hash values for measurement time series;

Determination of evaluation variables from measured value time series; - Adding the hash values and evaluation values to a distributed ledger

Database;

Checking compliance with the feed-in conditions on the basis of the evaluation variables in the distributed ledger database using a computer log (16) which depicts the feed-in conditions.

2. The method according to claim 1,

characterized in that

a measurement time series is formed only when there is a fault signal on the part of the power network (1), preferably for the duration of the fault signal.

3. The method according to claim 2,

characterized in that

the measurement time series is supplemented by measurement values that were recorded a predetermined period before and / or after an error signal was present.

4. The method according to any one of the preceding claims,

characterized in that

the result of the check is stored in the distributed ledger database.

5. The method according to any one of the preceding claims,

characterized in that the hash value calculation for measured value time series and / or determination of evaluation variables for measured value time series for validation are carried out by more than one instance.

6. The method according to any one of the preceding claims,

characterized in that

the evaluation variable comprises the active power rate after clarification of a grid failure resulting in a voltage breakdown.

7. The method according to any one of the preceding claims,

characterized in that

The detection of the voltage and current per phase at the grid feed-in point is carried out by a calibrated and / or lead-sealed detection module (12).

8. The method according to any one of the preceding claims,

characterized in that

Detection of the voltage and current strength per phase is carried out at a sampling rate of at least 1 kHz, preferably of at least 2 kHz, further preferably of at least 5 kHz.

9. An arrangement (100) comprising at least one energy generation unit (4, 5) that feeds into a power network (1) at a network entry point,

characterized in that

a detection module (12) for detecting the voltage and

Current strength is provided per phase and the components of the arrangement (1) are designed to carry out a method according to one of the preceding claims.

10. Set of computer program products, comprising program parts which, when loaded into a computer or into interlinked computers, are designed to carry out the method according to one of claims 1 to 9.