DE202021003646U1 - Regulation and control assembly for PV panels - Google Patents

Abstract

Regulation and control assembly for PV panels, comprising a DC-DC converter and a microcontroller, which regulates and controls a plurality of control and regulation circuits, characterized in that the microcontroller works clocked on the input side with at least 3 strings of at least one panel can be connected alternately and is configured on the output side to provide a +-10% constant voltage that is at least 4 times higher, preferably a voltage of at least 100 V, particularly preferably a voltage of 230 volts.

Description

GENERAL AREA

The invention is located in the general field of electrics and electronics in photovoltaic systems. Photovoltaics, hereinafter abbreviated to PV, is based on the generation of electrical current from light quanta.

TECHNICAL BACKGROUND

The present invention relates to a regulation and control assembly according to the preamble of the independent claims. The purpose of the regulation and control assemblies in the PV sector is to improve efficiency. Electricity should be generated, stored and transmitted to where it is needed as efficiently as possible.

DESCRIPTION OF THE PRIOR ART

• Im Jahre 2003 offenbart die US2003/0048648 A1 einen DC-DC-Wandler mit Sensor, dessen Messwert zur Regelung des Wandlers herangezogen wird. In 5 ist ein IC offenbart, welcher regelnd eingebunden ist. Mehrere Feedback-Schleifen sind in den Erläuterungen offenbart und tragen zur Qualität der Regelung bei.
• Im Jahre 2004 offenbart die US2004/0249876 A1 Wandler für Stromnetze, wobei die Wandler gemäß der Absätze 26 ff. programmierbare Komponenten sowie Software umfassen können. Durch verbesserte Analyse der mit einer Frequenz anfallenden Messdaten über eine Betrachtung der Fehlerquadrate (Standardabweichung ) wird genauer ermittelt, welche Messwerte eine schädliche Leistungs-Spitze anzeigen und eine Abschaltung rechtfertigen.
• Im Jahre 2009 beschreibt die WO 2009/051853 A1 ein System zur hoch effizienten PV-Nutzung. Gemäß der Zusammenfassung auf Seite 1 sind Effizienzen von 92% bis hin zur optimalen Effizienz (nur noch Leitungsverluste durch die Stromleitungen) zugänglich. Mithin soll hier der jeweils optimale Leistungspunkt einer PV-Anlage angefahren werden. Nachteilig ist jedoch unter den vielen, ergänzenden und kombinierbaren Aspekten nicht erkennbar, wie dies sinnvoll auf Ebene eines oder weniger PV-Paneel umgesetzt und zuverlässig erreicht werden könnte.

PV is the subject of intensive research and is the subject of many innovations. In a chronological overview one can identify some established basic principles:

• In 2003 revealed the US2003/0048648 A1 a DC-DC converter with a sensor, the measured value of which is used to control the converter. In 5 discloses an IC which is involved in regulation. Several feedback loops are disclosed in the explanations and contribute to the quality of the control.
• In 2004 revealed the US2004/0249876 A1 Converters for power grids, which converters according to paragraphs 26 et seq. may include programmable components and software. Improved analysis of the measurement data occurring with a frequency via a consideration of the least squares (standard deviation) determines more precisely which measurement values indicate a harmful power peak and justify a shutdown.
• In 2009 describes the WO 2009/051853 A1 a system for highly efficient PV use. According to the summary on page 1, efficiencies from 92% to optimal efficiency (only line losses through the power lines) are accessible. Consequently, the optimal performance point of a PV system should be approached here. However, given the many additional and combinable aspects, it is disadvantageous that it cannot be seen how this could be sensibly implemented and reliably achieved at the level of one or fewer PV panels.

The object of the present invention was therefore to overcome the disadvantages of the prior art and to provide a regulation and control assembly for PV panels which, despite fewer and comprehensible measures, is able to provide significantly increased efficiency in the operation of PV panels.

This problem is solved according to the features of the independent claims. Advantageous embodiments result from the dependent claims and the following description.

SUMMARY OF THE INVENTION

According to the invention, the regulation and control assembly for PV panels comprises a DC-DC converter and a microcontroller, which regulates and controls a plurality of control and regulation circuits, the microcontroller working clocked on the input side with at least 3 strings of at least one PV panel is connected and on the output side a +-10% constant voltage that is at least 4 times higher, preferably a voltage of at least 100 V, particularly preferably a voltage of 230 volts, is designed to provide it. The advantage of this invention is that the integrated electronics can ensure that the individual strings or cells are always operated at their optimum, which was not possible until then. It is generally known that a photovoltaic cell has a so-called optimum effect that is related to its amperage load. If a panel is irradiated with light unevenly, this optimum effect of the individual cells is shifted in such a way that the overall efficiency of a panel can suffer in such a way that there can be a loss of up to 50% or more. Here, too, the present invention provides a massive remedy, since the cells are now each operated at their optimum individually or as a cluster.

DESCRIPTION OF THE INVENTION AND ADVANTAGEOUS FEATURES

According to the invention, a regulation and control assembly for PV panels, comprising a DC-DC converter and a microcontroller, which regulates and controls a plurality of control and regulation circuits, is claimed, the microcontroller working clocked on the input side with at least 3 strings at least of a panel can be connected alternately and is designed to provide a +-10% constant, at least 4 times higher voltage, preferably a voltage of at least 100 V, particularly preferably a voltage of 230 volts, on the output side.

The strings are preferably arranged galvanically isolated from one another.

The microcontroller preferably has a non-volatile memory, preferably an FRAM memory.

The microcontroller preferably has a power value memory, preferably a power value memory with a storage capacity of 3 years with value acquisition every minute.

The microcontroller preferably includes a CRISC processor.

Each string is preferably connected to at least one switchable relay on the input side.

Each string is preferably connected to at least one switchable relay on the output side.

The device preferably includes overload capacitors, which are integrated via control circuits to compensate for voltage peaks.

Each string can preferably be short-circuited by a relay.

The device claimed here preferably comprises a PV panel with a plurality of cell groups which are subdivided into at least 3 common strings which are galvanically isolated from one another and have two terminals and which emit direct current. A clocked microcontroller, which can advantageously be a clocked IC in the most cost-effective design, regulates each string successively on the access side to an optimal I-U ratio in order to be able to call up the available power with optimal efficiency. On the output side, an assigned step-up converter is connected for each string, which retrieves the power synchronized to the clock or in the same clock and regulates it up to a constant 230 V +-10% DC. These at least 3 Abagbe contacts of the strings, connected in parallel, lead to an output connection, which always provides 230 +- 10% volts. The software that is executable on a data carrier or a processor therefore provides a minimum sequence of commands, which first checks on the access side for available and usable power; in the event of insufficient power, switching off and de-contacting the respective string for the remaining process is advantageous; increasing the I-U values of the usable strings to maximum efficiency within each string; connecting the respective set string to the associated step-up converter; increasing the voltage to 230 +- 10 V DC; Delivery of the built-up power up to 80% residual efficiency; disconnecting all contacts; return to command 1 and start a new command sequence as before; provides. Optionally, the cycles of the individual strings are offset against each other with increased frequency in order to provide greater consistency in the power available on the output side with highly uniform usage conditions. Usual devices can be connected via a simple DC-AC converter or DC devices can be directly connected. The latter allows a power grid to be set up in which the AC-DC converters that would otherwise be required in the respective end devices can be eliminated in an advantageous and resource-saving manner. Against this background, the present innovation also reveals an overall concept in which PV panels equipped according to the invention can supply power directly to both DC and AC end devices in a hybrid network via standard, inexpensive cables; Supplemented by step-down converters, the usual voltages of digital end devices can allow the integration of usual electronics, up to the simpler integration of smart home automation concepts.

Further advantages result from the exemplary embodiments. It goes without saying that the preferred features, advantages and exemplary embodiments described above are not to be interpreted as restrictive. Advantageous or preferred additional features and additional combinations of features, as explained in the description and known as technical background, can be realized within the scope of the independent claims in the claimed subject matter as additional features and measures, both individually and in different combinations, without the range of the invention would leave.

DETAILED EXPLANATION OF THE INVENTION USING EXEMPLARY EMBODIMENTS

The special feature of the power-up solar cells relevant here, hereinafter referred to as PUSZ, is that the voltage in or directly on the individual or several cells is increased directly or indirectly without a high loss due to voltage drop of the external diodes ins weight falls. The great advantage is based on the fact that the voltage is increased directly in the cell or directly on the cell to a higher voltage of at least 100V, preferably 230V +/-10%.

Normal photovoltaic cells have a voltage between 0.3V to 0.7V and even the best Shottky diodes available have an average voltage drop of 0.3V under load, which accounts for 70 - 95% or even more of their output for individual cells. This means that, for example, in a “Junction Box” the power of 1-3 cells per panel will be lost in the diodes. If you now set the voltage in a preferred embodiment of the present invention for monocrystalline cells by means of an integrated circuit to a constant 100V, preferably 230V +/- 10%, the 0.3V voltage drop will only be a fraction of the percentage and all cells could be parallel in the string be nested. This then also has the further advantage that the voltage drop in the conductor tracks or connections between the cells is no longer of such importance due to the length of the lines.

The chip-based voltage step-up technology provided here is already available in many variations in other technical areas. For example, in flash memory chips, the programming voltage is directly increased from the approximately 3V operating voltage to 17V. Or there are also chips available today for so-called VFD display tubes that increase the voltage internally to 60V, for example, without external components.

Such methods can advantageously be integrated directly into the solar cell wafer under the connection points as a circuit using special doping, as is also used today in a similar way to TFT displays. When laminating the solar cell wafers, it would also be possible to integrate external booster circuits as inductive microcircuits with microcoils or capacitive boosters with so-called "CerCos" (ceramic capacitors).

According to the current state of the art, it is generally known that the amperage decreases more than the voltage in longer lines.

For this reason, step-up transformer stations are built today and the mains voltage is transmitted as high voltage in order to minimize losses in the long lines.

If you now apply the method and corresponding circuits to photovoltaic cells in the panel, the efficiency is very constant; By connecting at least 3, preferably more, strings in parallel within a panel, the voltage is constant even if, for example, individual cells are partially covered by leaves or dirt. Normally a panel in this situation loses up to one complete string (row of cells) in a panel, which is then decoupled from the solar cell array by means of the diodes in the "junction box". The present invention now provides a remedy here, as each cell or cluster of cells always generates, for example, 100V, preferably 230V+-10%. This is done, for example, by increasing the voltage, which is integrated or directly added to the cell. Another advantage is that decoupling already takes place and external decoupling is even superfluous. For example, through the loss of a single 1.2 watt cell (instead of 0.6V and 2A, 100V and 12mA are now flowing), the loss in the contacts and the connection strings is reduced from a few percent to a few per thousand. That is, the minimal loss of the booster circuit is offset by the reduced loss here. For example, even better efficiency than before can be expected per panel. This now also brings the decisive advantage that the anodes or cathodes of all cells can be mounted on a conductive plate, so that the rear string can be omitted and thus optimal heat dissipation and electrical contacting of the cells can be realized more compactly.

It is also well known that the electrons generated by the photons cannot "flow away" quickly enough, which often results in a reduction in the efficiency of the cell. Here, too, the present invention provides an advantageous remedy. A controlled control of this circuit can now pulsate the so-called electron clouds from the silicon and increase the efficiency percentage again.

The control behavior programmed into the at least one microcontroller can also be explained as a method. It goes without saying that the term 'method' refers to an executable code programmed into the claimed device, which is designed as a control and regulating assembly via the corresponding sub-assemblies familiar to a person skilled in the art. Consequently, the present device offers a method which results in a constant, increased output voltage of photovoltaic cells. A step-up circuit or circuits is advantageously integrated directly in or on the cells or cell clusters.

External step-up circuits are preferably attached directly to the cells or cell clusters, these increasing the voltage by means of coils in order to reduce the power loss in the connections. External step-up circuits are preferably attached directly to the cells or cell clusters, which use capacitors and/or voltage multipliers to increase the voltage in order to reduce the power loss in the connections.

Booster circuits are preferably integrated into the cells, thus booster circuits increase the voltage to reduce the power dissipation in the connections.

The voltage is preferably increased in order to reduce the power loss in decoupling diodes.

The exposure-dependent performance data arising from photovoltaic cells are preferably used to optimize the effect by increasing and regulating the operating voltage.

Power shifts between the strings are preferably also used through direct or indirect control circuitry.

The voltage of the cell is preferably directly or directly set significantly above the voltage drop of the decoupling diodes.

The voltage of each string is preferably increased directly in the claimed control circuit on the respective panel.

The voltage is preferably converted into a grid-synchronized grid voltage.

The control circuit preferably measures cyclically available parameters, determines an optimal watt peak in a U/I curve and it is readjusted accordingly, so that the cells are permanently operated at optimal efficiency.

In a photovoltaic cell with an integrated circuit under the rear connections, the voltage is preferably boosted. An external step-up circuit preferably implements the increased operating voltage of the photovoltaic cell.

The increased voltage is preferably realized in a cluster of 4 cells and via a central voltage multiplier circuit. This can then be brought together and diverted via a busbar in the panel.

A voltage multiplier circuit is preferably implemented as a parallel interconnection of individual cell clusters.

A parallel interconnection of the individual strings is preferably implemented in a panel with the aid of the voltage multiplier circuit.

INDUSTRIAL APPLICABILITY

Established photovoltaic panels - hereinafter referred to as PV panels - are only insufficiently adjusted to I-U values with maximum efficiency of power utilization and thus cause an increased need for resources and hardware required on the output side.

The task is to provide a control and regulation assembly that takes this disadvantage into account.

The solution is achieved with a control and regulation assembly that checks assigned subgroups of the PV panel in a clocked manner, adjusts them to optimal I-U values and finally makes the power available on the output side with a constant output voltage.

This increases the efficiency of PV panels and significantly reduces the hardware requirements in the interface area of locally connected home and house networks. PV electricity is provided more efficiently and is easier to use with simpler end devices.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 2003/0048648 A1 [0003]
• US 2004/0249876 A1 [0003]
• WO 2009/051853 A1 [0003]

Claims (10)

Regulation and control assembly for PV panels, comprising a DC-DC converter and a microcontroller, which regulates and controls a plurality of control and regulation circuits, characterized in that the microcontroller works clocked on the input side with at least 3 strings of at least one panel can be connected alternately and is configured to provide a +-10% constant voltage at least four times higher on the output side, preferably a voltage of at least 100 V, particularly preferably a voltage of 230 volts. Device according to the preceding protection claim, characterized in that the strings are galvanically isolated from one another. Device according to one of the preceding protection claims, characterized in that the microcontroller has a non-volatile memory, preferably an FRAM memory. Device according to one of the preceding protection claims, characterized in that the microcontroller has a power value memory, preferably a power value memory with a storage capacity of 3 years with value acquisition every minute. Device according to one of the preceding protection claims, characterized in that the microcontroller comprises a CRISC processor. Device according to one of the preceding protection claims, characterized in that each string is connected to at least one switchable relay on the input side. Device according to one of the preceding protection claims, characterized in that each string is connected to at least one switchable relay on the output side. Device according to one of the preceding protection claims, characterized in that the device comprises overload capacitors which are integrated via control circuits to compensate for voltage peaks. Device according to protection claims 6 and 7 , characterized in that each string is designed to be short-circuitable. Device according to any of the preceding claims.