• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a method and a device for off-grid detection in self-generating systems, in which a island criterion associated with an island grid operation is checked by at least one electrical state variable of a public power grid is detected and determined whether it leaves a predetermined tolerance range. Reliable off-grid detection is achieved by triggering a time measurement when a departure from the tolerance range (30) is detected and by emitting a detection signal for off-grid operation within a predetermined period (At) of at most five seconds after the start of the time measurement, if the state variable is continuously outside the tolerance range (30) during the period (At).
    公开号:AT511649A2
    申请号:T699/2012
    申请日:2012-06-20
    公开日:2013-01-15
    发明作者:
    申请人:Changetec Ag；
    IPC主号:
    专利说明:

    The invention relates to a method for island detection in self-generating systems, in which an island island operation associated island criterion is checked by at least one electrical state variable of a public power grid is detected and determined whether it leaves a predetermined tolerance range, as well as to an apparatus for performing the process.
    Such a method and such a device for island mesh detection is addressed in DE 10 2009 047 980 ^ 1. Here, in the context of an activation control device for driving a circuit breaker device also, as is conventional, checked by means of a monitoring device, if there are disturbances on the public power grid, which make a separation of a self-generating system (decentralized energy supply system) from the public network required. As a criterion, the frequency and voltage in a connection region to the public power network is monitored by means of monitoring electronics of the monitoring device as an electrical state variable and it is determined whether changes in the electrical state variable (n) leave predetermined limit values of a tolerance range. If this is the case, a circuit breaker device is controlled with contactors and the self-generating system disconnected from the public grid Previous monitoring devices include for detecting the electrical variable size (s) monitoring electronics with actively switchable electrical components, which mean a considerable circuit and control effort and also consume even electrical energy.
    In the standard VDE 0126-1-1 it is prescribed that a (decentralized) electricity self-generator by a release point, such. B. a bidirectional Sicherhertsin-terface (BiSi) must be disconnected from the public grid, as soon as an island criterion for a stand-alone operation is present. This is z. As is the case when the public power grid is turned off by the power company for repair purposes. The shutdown must be recognized by the generator and cause its separation from the public grid. Thus, the public power lines are voltage-free and accessible for construction. In conventional known methods cyclic short-term stress tests are performed on all three network phases by switching on inductive or capacitive loads. The height of the existing network impedance determines the resulting voltage level, which is used as the island criterion. Off-grid operation is present when the grid is switched off or interrupted. Due to the increased network impedance when the network is switched off, load changes due to test pulses have a much greater effect on the mains voltage than in the case of public networks connected to the self-generating system. Thus, mains voltage dips are forced by active methods for island grid detection, which are detected, which can be concluded that an island grid.
    The invention has for its object to provide a method and an apparatus for island detection in self-generating systems that or with the least possible effort results in a secure island network detection.
    This object is achieved with the features of claim 1 or 9. It is provided that when a departure from the tolerance range is detected, a time measurement is triggered and a detection signal for the off-grid operation within a predetermined period of no more than five seconds after the start of the time measurement is issued, if the state variable during the period continuously outside the Tolerance range is.
    In the apparatus, it is provided that the time measuring device is actuated for the immediate triggering of a time measurement signal when at least one measured value leaves the tolerance range and that the evaluation device is designed to generate a detection signal for off-grid operation within a period of at most five seconds from the triggering of the time measurement signal outputs when the state variable during the period continuously outside the tolerance range is the detection signal can be a separation of the self-generating system from the public grid, for. B. cause by means of a corresponding control signal.
    By triggering the time measurement and the specified period of time during which the state variable must be outside the Toieranzbereichs, it is avoided that z. B. accidental short-term exceedances of the tolerance range falsely lead to island detection. The time span is sufficiently short, z. 8, no more than three, four or five seconds to ensure fast island detection. Advantageously, the method can be carried out by means of software programs which result in flexible, optimized adaptation possibilities to different circumstances. With the method or the device, expensive active measures such as the connection of inductive or capacitive loads are unnecessary, so that the island grid recognition can be performed passively, whereby the own energy consumption of the device is significantly reduced.
    An advantageous embodiment with which a time measurement for determining an in-selkriteriums can be triggered quickly again, is that the timing is reset and not recognized on a stand-alone operation when the state variable falls within the time period in the tolerance range.
    At a low cost, the measures contribute to the fact that the at least one electrical state variable takes place by means of an existing monitoring device of an enabling device without active connection of an additional load.
    Various design variants consist in that the at least one electrical state variable is at least one voltage, at least one frequency or at least one phase angle or that a combination of at least two of these state variables is detected and used for the evaluation in order to check the island criterion. A combination of at least two state variables results in an increased reliability in the determination of the island criterion, wherein compared to the evaluation of only one state variable and a narrower tolerance range can be selected. For carrying out the method, the measures are advantageous in that the tolerance range is limited by an upper threshold value lying above a preset value of the respective state variable and a lower threshold value lying below the preset value of the relevant state variable.
    In this case, an advantageous embodiment of the method is that the upper threshold value and the lower threshold value are or are selected to be at most 10% away from the predefined value. Investigations by the inventors have shown that threshold values or limit values of the tolerance range of ± 6% of the standard value give meaningful results for island operation. Threshold values of not more than + 4% or ± 5% are also conceivable, in particular if a combination of state variables or a more differentiated processing, eg. B. more accurate measured value analysis possibly with statistical evaluation, flows.
    An advantageous embodiment of the method and correspondingly also of the device for reliable recognition of an island network operation is based on a predefined standard value of the state variable or a time-averaged measured value of the state variable over a specific time interval, the time interval being a Many times longer than the time span for the tripping of the islanding network detection.
    The embodiment of the method in such a way that the examination of the island criterion and the triggering of the detection signal or of the control signal are software-controlled results in flexible possibilities for adaptation and optimization with regard to different circumstances and / or future requirements. The same applies to the relevant embodiment of the device.
    The invention will be explained in more detail by means of embodiments with reference to the drawings, in which:
    1 shows a block diagram of a device for islanding network detection,
    2A is a diagram with a measured value profile to a state variable and a tolerance range,
    FIG. 2B shows a further exemplary embodiment for a measurement value of a state variable with a defined tolerance range and
    2C is a diagram with the measured value curve to a state variable corresponding to FIG. 2B with a time-adjusted tolerance range, FIG.
    Fig. 1 shows essential components of a device for island detection of a self-generating system, such. B. a photovoltaic system, a combined heat and power plant or a wind turbine. By means of a measuring device 10, z. B. a three-phase amplifier, is at junctions of three phases L1, LZ, L3 of a (not shown) public power system at least one electrical state variable, such. B. a mains voltage U of one or more phases, the frequency f of one or more phases and / or the phase angle φ one or more phases detected, whereby corresponding first, second and third measured values 11, 12, 13 of the three phases L1, L2, L3 are available, which describe a respective electrical state variable of the public power grid and are supplied to an evaluation device 20 for further processing. In the evaluation device 20 a Erkennungssignai or an output-side control signal 27 is formed, which is a separation device such. As a Schaitvorrichtung with shooters, is supplied to separate the self-generating system from the public power grid when an island criterion is detected for an island operation. «7 ft *
    The evaluation device 20 comprises a first, second and third calculation module 201, 202, 203, to which the first, second and third measured values 11, 12, 13 are fed, in order to obtain first, second and third time-averaged measured values 24, 25 and 26 form. The first measured values 11 and the first averaged measured values 24 are fed to a first comparator 211, whose output is connected to a first timer 221 whose output signals are fed to an evaluation module 230. Accordingly, the second measured values 12 and second averaged measured values 25 are fed to a second comparator 212, whose output is connected to a second timer 222 whose output signals are supplied to the evaluation module 230. The third measured values 13 and third averaged measured values 26 are fed to a third comparator 213, whose output is connected to a third timer 223, whose output signals are also supplied to the evaluation module 230. The evaluation module 230 forms the detection signal for the isolated operation or the control signal 27, which is emitted at the output of the evaluation device 20.
    The processing and evaluation of the measured values 11, 12, 13 and the averaged measured values 24, 25, 26 and possibly further data in the evaluation device 20 are at least for the most part preferably software-controlled or by means of program modules, for which corresponding processing devices and memory devices in the evaluation device 20, in particular at least one integrated computer unit, such as a microcontroller, are present. The illustrated processing blocks are accordingly to be understood symbolically for relevant program modules. Alternatively, the illustrated units may be at least partially formed of hardware components. -8th-
    The measuring device 10 preferably consists of hardware components, but may also contain software components or program modules for processing the measured values 11, 12, 13, and may also contain, for example, B. be controlled by means of a Mikrocontrolfers.
    In order to form the averaged measured values 24, 25, 26, the measured values 11, 12, 13 are recorded in the relevant calculation modules 201, 202, 203 and transmitted via a predetermined or predefinable, eg. B. via a program changeable, time interval! averaged, the z. 30 seconds or one or more minutes, so that the averaged readings reflect a slow voltage change taking place in the public power grid, such as with increased power consumption at noon, without any abrupt changes interfering with it.
    In the comparators 211, 212, 213, tolerance ranges 30 are formed between an upper and lower threshold value OS, US (see FIGS. 2A to 2C), and it is checked whether the respective electrical state quantity descriptive measured values 11, 12, 13 within the tolerance range 30 lie or leave this. In the exemplary embodiment shown in FIG. 1, the respective mean measured value 24, 25 or 26 is used as the upper threshold OS and a threshold value 6% above the default value and the lower threshold US below the same percentage deviation below Default value. In this way, the respective averaged measured value 24, 25 or 26 determines the position of the tolerance range 30, which is carried along in time according to the averaged measured value 24, 25 or 26, as shown in FIG. 2C. This ensures that the measured values 11, 12, 13 normally remain substantially in the middle range of the tolerance range 30 and do not approach a threshold value OS or US when the voltage in the public power supply changes as a function of the load, as in FIG. 2B for the case shows that a > Mr
    Load tests must be carried out by switching on inductive or capacitive loads, which represent a relatively high energy losses on the one hand and on the other hand can cause glitches and associated errors. For monitoring the electrical state variable of the public power grid existing hardware components of the monitoring device of the self-generating system can be used anyway, while the actual evaluation for the determination of the island criterion is advantageously carried out by means of software. The configuration by means of software also offers flexible adaptation options to various generators (eg photovoltaic system, combined heat and power plant, wind turbine system), which can also influence the detection of the electrical state variable. In this way, z. Example, the tracking of the default value, such as the duration of the time interval for the temporal averaging of the measured values, the type of time averaging {sampling intervals, number of sampling points, type of temporal or statistical average and the like.) And the determination of the size of the tolerance range, be taken by programming without changing hardware components suitable. An adaptation to changed standards or different networks is advantageously possible in this way, whereby an automatic adaptation can be implemented by recognizing different systems.
    Vienna, the 2Q. JUiii tuU
    权利要求:
    Claims (11)
    [1]
    Dr. Müllner Dipl.-Ing.: Kttts'efci1Vikä Q £ G " Patent Attorney's Office Weihburggasse S ^ Pijstfeih > 59. · A »1 Oj4 V {IEN Austria Telephone: c +43 {1} 512 24 81 / Fax: - * + 43 (1) 513 76 81 / e-mail: r »: repatenS@aon.at Account (PSK): 1480 708 BLZ 60000 BIC: OPSKATWW IBAN: AT19 6000 0000 0148 07081 480 708 13a / Ö 45586 changetec AG 71691 Freiberg (DE) Claims: 1. A method for island network detection in Eigenerzeugeraniagen in which a coherent with a stand-alone operation Inseikriterium is checked by at least one electrical state variable of a public power grid is detected and determined whether it leaves a predetermined tolerance range, characterized in that then when a departure from the tolerance range (30) is detected, timing is triggered, and a detection signal for off-grid operation is given within a predetermined period (At) of at most five seconds after the start of the time measurement d, if the state variable during the period (At) continuously outside the tolerance range (30).
    [2]
    A method according to claim 1, characterized in that the time measurement is reset and unrecognized for off-grid operation if the state quantity falls within the tolerance range (30) within the time period (Δt).
    [3]
    3. The method of claim 1 or 2, characterized in that the at least one electrical state variable by means of an existing monitoring device of a free-running device without active connection of an additional load. • · · · · * * ♦; · «« «· · ** · " * Δ * Λ-» + «« »· *
    [4]
    4. The method according to any one of the preceding claims, characterized in that the at least one electrical state variable is at least one voltage, at least one frequency or at least one phase angle or that a combination of at least two of these state variables is detected and used for the evaluation to verify the island criterion ,
    [5]
    5. The method according to any one of the preceding claims, characterized in that the tolerance range (30) is limited by a above a default value of the respective state variable lying upper threshold (OS) and lying below the default value of the respective state variable lower threshold (US).
    [6]
    A method according to claim 5, characterized in that the upper threshold (OS) and the lower threshold (US) are or are selected to be at most 10% away from the default value.
    [7]
    7. The method according to claim 5 or 6, characterized in that as the default value a fixed predetermined normal value of the state quantity is used as a basis or over a certain time interval averaged measured value (24, 25, 26) of the state quantity is based, wherein the time interval to a multiple is longer than the time period (At).

    3 - • * • ·
    [8]
    8. The method according to any one of the preceding claims, characterized in that the verification of the island criterion and triggering of the control signal (27) are performed software controlled.
    [9]
    9. A device for carrying out the method according to one or more of the preceding claims with a monitoring device for detecting an island criterion for a Inseibetrieb with a measuring device (10) for detecting at least one electrical state variable of a public network and a time measuring device having evaluation (20), with the It can be determined whether the electrical state quantity leaves a predetermined tolerance range (30), characterized in that the time measuring device is triggered to trigger a time measurement signal if at least one measured value (11, 12, 13) leaves the tolerance range (30) and if the evaluation device ( 20) is adapted to emit a detection signal (27) for the island operation within a time period (At) of at most five seconds from the triggering of the timing signal, if the state quantity during the period (At) continuously outside the tolerance range (30) lies.
    [10]
    10. The device according to claim 9, characterized in that the tolerance range (30) by a above a default value of the respective state variable lying upper threshold (OS) and below the default value of the state variable underlying lower threshold (US) is limited and that the evaluation device (20) for calculating a measured over certain time intervals measured value (24, 25, 26) of the state variable is used as the default value for setting the upper and lower threshold (OS, US) is based, wherein the time interval selected by a multiple longer is the time span (At).
    [11]
    11, device according to claim 9 or 10, characterized in that at least parts of the evaluation device (20) are formed by means of program modules, Vienna tO. June 2012
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    同族专利:
    公开号 | 公开日
    AT511649A3|2016-09-15|
    DE102011051199A1|2012-12-20|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP1764894A1|2005-09-19|2007-03-21|ABB Schweiz AG|Method for detecting islanding operation of a distributed generator|
    DE102007049251A1|2007-10-12|2009-04-23|Repower Systems Ag|Wind turbines with regulation for network faults and operating methods therefor|
    DE202009018199U1|2009-10-01|2011-06-09|changetec GmbH, 71691|Unlock control unit|CN103091578A|2013-01-11|2013-05-08|天津理工大学|Island detection method of photovoltaic grid-connected system|
    CN103743976A|2013-12-30|2014-04-23|西安爱科赛博电气股份有限公司|Side-frequency harmonic current disturbance island detection method|
    DE102017126996A1|2017-11-16|2019-05-16|Solarinvert Gmbh|inverter means|
    法律状态:
    2017-02-15| REJ| Rejection|Effective date: 20170215 |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102011051199A|DE102011051199A1|2011-06-20|2011-06-20|Method for islanding detection in self generating system, involves triggering time measurement, if abandonment of tolerance range is determined, where recognition signal is delivered for island operation within predetermined time period|
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