"SAFETY, MONITORING AND PROTECTION EQUIPMENT AND USE

THEREOF"

Technical Domain

The present application describes a safety, monitoring and protection equipment and use thereof.

Background

In the market of components and systems for photovoltaic centrals, there is a large range of separate or grouped solutions in protection and monitoring, eventually including safety. These solutions present as characteristics the fact that they are installed in the concentration places, immediately before or close to the localization of the inverter equipment, that is, at the end of the set of cable originating from the module groups, which in this text are defined as conduits.

The inverter equipment itself has analysis circuits for the defects of upstream isolation thereof, turning off and thus protecting in some way the inverter itself by interrupting the current flow of the conduit.

The deballast, protection and monitoring functions are carried out together in a location which will be as distant as the size of the photovoltaic central, therefore, in view of this premise, the defects originated upstream and which in physical terms are effective are not solved by any of the equipment described and known to the state of the art. Summary

The present application describes a safety, monitoring and protection equipment that comprises a deballasting component, DC fuses in each pole and group diode, Hall effect current sensor and voltage sensor per voltage divider, wherein said equipment is installed at the beginning of the DC conduits close to the photovoltaic module groups.

In one embodiment, one safety, monitoring and protection equipment is installed for each module group.

In one embodiment, the Hall effect current sensors and voltage sensor per voltage divider of the equipment for safety, monitoring and protection are integrated in RS485 and/or wireless communications.

In another embodiment, the deballasting component of the safety, monitoring and protection equipment is a solid state relay .

In still another embodiment, the deballasting component of the safety, monitoring and protection equipment is placed in series with the negative pole of the photovoltaic module group .

In one embodiment, the group diode of the safety, monitoring and protection equipment is placed in series with the positive pole of the module group.

In still another embodiment, the safety, monitoring and protection equipment is assembled in the interior of a box with MC4-type connectors or others suitable for use in photovoltaic centrals.

The present application further describes the use of the safety, monitoring and protection equipment in photovoltaic centrals .

General Description

A photovoltaic central consists of photovoltaic modules, cables, DC/AC protection devices, inverters and monitoring devices. The physical location of the equipment involved in said constitution is specific:

• Photovoltaic Modules - rooftops or open spaces (soil);

• Cables - established among the components of the photovoltaic central, both in the DC as in the AC side;

• Inverters - installed in technical zones or rooftops;

• Monitoring devices - of the inverter itself or placed in the DC or AC grouping enclosures.

For all the used references to upstream and downstream, the reference point is the photovoltaic central.

In case of serious defects, such as for example a short- circuit in the photovoltaic central conduits on the DC side, upstream from the DC protection and grouping enclosures, the defect is fed by the photovoltaic generator closing a current loop. In view of the range of the defect, we might have short-circuit currents much higher than the cable fusion current values, which in these conditions might lead to a fire which may affect the conduits, equipment, rooftops and ultimately, all of the location where the photovoltaic central is installed.

In the cases where there is a serious defect in the DC conduits, there is no equipment capable of carrying out the deballasting of the module groups, since it is not possible to turn off solar light, therefore, there is the need to place an equipment at the beginning of the modules, which in case of defects may be activated in an automatic or manual manner to interrupt the short-circuit current flow, and in case of the need of intervention by firefighters, an electrocution danger free place is created for combating a fire outbreak in the central or related zones.

The safety, monitoring and protection equipment comprises a deballasting component responsible for the safety of the system. DC fuses in each pole and group diode to avoid inverted connections, which components are responsible for the protection of the system. Hall effect current sensors and voltage sensor per voltage divider, components responsible for monitoring. The Hall effect current sensors and voltage sensor per voltage divider are integrated in RS485 and/or wireless communications or any other suitable communication protocol.

The safety, monitoring and protection equipment will be installed at the beginning of the DC conduits together with the module groups (string), being one placed for each group, with the main function of allowing the opening of the DC circuit of these modules groups, in an automatic or manual manner . The monitoring and protection equipment is built with material that is non-flammable, watertight and with high mechanical resistance, such as for example a UV resistant, fire retardant polymer. According to the constructive base, the equipment only works when fed by an auxiliary current, by means of non-flammable conductors so that in case of defect in this feed there is no flow of current from the photovoltaic modules.

The deballasting component incorporated in the equipment, which may be a solid state relay, is not mechanical thus it does not have movable parts, it is immune to the electrical arch capable of being formed in the interruption of an electric DC circuit and the auxiliary feed is an optically insulated deballasting circuit. This deballasting component has a location close to the negative pole so as to interrupt the current immediately at the source and not on its return, working on the principle that the current flow will be made from the negative to the positive.

The equipment has as its main function, the guarantee of safety and two more incorporated functions, one of protection and the other of monitoring. The protection function consists of a DC fuse ( 1000/1500Vdc) in both poles and a group diode to avoid inverted currents in cases of bad connection. These functions may be signalized, locally or not, by means of light signals. The monitoring function has the purpose of collecting the sampling of the current (A) and voltage (V) values of the group and states.

The placing of the equipment at the beginning of the conduit of a module group has as a premise the fact that a short- circuit of only one group is not serious for the cables nor the modules, since the voltage of a short-circuit in a group is equal to the voltage of a short-circuit of a module and very close to the working voltage of the group itself. Downstream from this point, with the agglomeration of groups in common conduits may cause much higher short-circuit voltages .

This equipment was created with the focus on photovoltaic centrals located on rooftops, whether industrial, residential or service, where it is necessary to guarantee the protection of people, property and animals and to create conditions so that the official entities are able to intervene in case of fire whether caused or not by the photovoltaic central without the danger of being electrocuted .

Brief Description of the Figures

For an easier understanding of the present application figures are attached, which represent embodiments which, however, do not mean to limit the technology disclosed herein .

Figure 1 illustrates an installation scheme of a photovoltaic central according to the state of the art.

Figure 2 illustrates a type scheme of a photovoltaic central with the inclusion of the safety equipment disclosed herein.

Figure 3 illustrates a scheme for a physical box of the safety equipment disclosed herein. Figure 4 illustrates an internal block diagram, a one-line diagram and components that constitute the safety equipment disclosed herein and where the following elements appear:

El - Group Entry (-)

E2 - Group Entry (+)

FI e F2 -DC Fuse type gG PV

R1 e R2 - Group tension measurement

Trl - Measurement transducer (I and V)

COM - External communication

II - Group current measurement

STR1 - Deballasting component

D1 e D2 - Diodes in row

51 - Group Exit (-)

52 - Group Exit (+) .

Figure 5 illustrates the stages of development of the equipment, in its natural/off state (1) and on (2) .

Description of embodiments

Referring to the figures, some embodiments are now described in a more detailed manner, which do not intend, however, to limit the scope of the present application.

The safety, monitoring and protection equipment comprises a deballasting component, which is responsible for the safety of the system. DC fuses in each pole and group diode to avoid inverted connections, components responsible for the protection of the system, and Hall effect current sensors and voltage sensor per voltage divider, which are components responsible for monitoring. The Hall effect current sensors and voltage sensor per voltage divider are integrated in RS485 and/or wireless communications or any other suitable communication protocol.

The main aspects and distinguishing criteria of this equipment from the ones known to the state of the art are the safety function and the functions of protection and monitoring, grouped with the first in one single device, placed at the beginning of the DC conduits in each photovoltaic module group.

The safety function of the equipment is carried out by means of the deballasting component, non-mechanical, such as for example a solid state relay 1000/1500Vdc 25A NO, placed in series with the negative pole of the module group.

The protection function against overcurrents with DC FV 12- 16A fuses in series with positive and negative pole and the protection function against inverted polarity by means of diode placed in series with positive pole of the module group .

The equipment box may comprise MC4-type connectors allowing the interconnection with the majority of the systems installed and which will be installed, without the need of equipment, material or extra tools. Thus, the monitoring function is guaranteed by the incorporation of monitoring (V-A) and states, integrated by means of communication cables (RS-485) and/or RF in existing systems (SCADA) or platform to be development with a similar purpose. The monitoring system must be suitable for the equipment in terms of integration. The monitoring is thus incorporated by reading the current which is made by the Hall effect current sensors and voltage sensor per voltage divider with transducer and remittance of the data through the RS485 and/or wireless circuit .

Figure 1 illustrates a typical photovoltaic central scheme as installed with the state of the art, where the purpose of this scheme is to show the typology of a photovoltaic central. The photovoltaic centrals present this type of scheme in constructive terms, altering solely the quantity of equipment according to the purpose.

Figure 2 illustrates a typical photovoltaic central scheme with the inclusion of the safety, monitoring and protection system. As can be seen in this Figure 2, the safety, monitoring and protection equipment is installed at the beginning of the DC conduits with the photovoltaic modules, one being placed for each group, with the main function of allowing in an automatic or manual manner to effect the opening of the DC circuit of this photovoltaic module group.

Figure 3 illustrates a scheme of the physical box of the equipment. The importance of this scheme is the fact that the box has, at entry and exit, MC4-type connectors so as to facilitate the installation in photovoltaic centrals both new and existing, since 99% of the typical connectors used in photovoltaic centrals are of the MC4-type. This detail turns the equipment into Plug & Play type.

Figure 4 illustrates an internal block diagram, a one-line diagram and components that constitute the equipment. This scheme clearly identifies the three functionalities, safety, protection and monitoring. In this figure it is clearly verified that the safety, monitoring and protection equipment comprises a deballasting component, responsible for the safety of the system, which may be a solid state relay with technology based on the Insulated Gate Bipolar Transistor (IGBT) which allows switching state in a quick and efficient manner. The equipment further comprises DC fuses in each pole and group diode to avoid inverted connections, responsible for the protection of the system and the Hall effect current sensors and voltage sensor per voltage divider, responsible for monitoring.

Figure 5 illustrates the working stages of the equipment. In this figure it is intended to show the two main states of working, the off state, entitled state 1) and natural to the equipment, which means solely installed in a group and not fed by an external source. When the equipment is off, the state will always be off, so there is safety in case of failure of external feed. The on state, entitled state 2), when externally fed allows the photovoltaic module group to work perfectly.

Since the energy production systems by means of solar photovoltaic are very specific in constructive terms, the equipment introduces the safety component installed in a strategic place. Other functions are coupled to this component, such as protection and monitoring, making it a unique product, straightforward to install and of general use .

Analyzing the immense photovoltaic park installed in rooftops, whether residential, industrial or of services, in global terms, where there were and are specific legal rulings directed to these locations, the concern and dissemination of the safety systems associated to the protection of people, properties and animals to avoid accidents with the primary production source (solar) will be of global scope.

The technology is used in photovoltaic centrals that are already installed or to be installed with main focus on rooftops of buildings.

The present description is not, naturally, in any way restricted to the embodiments shown in this document and one with average skills in the area may foresee many possibilities of alteration of the same without departing from the general idea, such as defined in the claims. The preferred embodiments described above are obviously interchangeable among themselves. The following claims additionally describe preferred embodiments.