ES2957852A1 - ENERGY DEMAND OPTIMIZER SYSTEM FOR ELECTRICAL MICROGRIDS (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Energy demand optimizing system for electrical microgrids, with which the power exchange with the power system (PS) is managed and participates in the potential/frequency control of the power system (PSC), the microgrid comprising at least one selected element from among thermal controllable loads (TCL), renewable energy generation systems (RES), energy storage systems (ESS) or a combination of them; comprising a supervisory device that is in connection with at least one element selected from: an inverter, which manages the RES and/or ESS; one or more converters, which manage the RES; and an optimizing device that manages the TCLs; where the supervisory device comprises a communications module that keeps the elements of the microgrid connected, which comprises a system management computer program and where the supervisory device establishes whether or not to participate in the PSC. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

ENERGY DEMAND OPTIMIZER SYSTEM FOR ELECTRICAL MICROGRIDS

TECHNIQUE SECTOR

The present invention consists of an energy demand optimizer system for electrical microgrids intended to improve management related to the generation, distribution and the growing penetration of renewable energy in the industrial sector.

Specifically, the present invention falls within the equipment and systems related to electrical and energy engineering, within these, those related to electrical microgrids.

BACKGROUND OF THE INVENTION

As is known within the industrial sector related to energy, the environmental and energy dependency problems suffered by most developed countries make them opt for energy self-sufficiency of homes. This new and decisive step towards distributed generation brings economic and environmental benefits because it encourages the integration into the electrical grid of facilities based on renewable energy sources. However, its presence can also lead to technical difficulties in the control and safe operation of the network, such as: distributed generation introduces bidirectional power flows; protection schemes must be redesigned towards more complex systems that avoid unintentional disconnection of end users and unintentional supply of disconnected areas of the network; Due to their very nature, most renewables work intermittently and unpredictably; and renewables are normally connected to the grid through interfaces based on power electronics. This causes difficulties to appear in the line of power quality that are even more relevant than those already existing in the traditional network. These interfaces also contribute to the proliferation of nonlinear charges.

One way to address this problem is through the use of microgrids (^grids). A microgrid is a network that is composed of a generation and distribution system, usually low voltage, that integrates distributed energy sources, such as microturbines, fuel cells, photovoltaics or wind, along with energy storage systems, such as batteries, supercapacitors, flywheels or others, and manageable loads. Furthermore, this microgrid can operate connected to the general electrical grid and can also operate in isolation, disconnected from the general electrical grid, by having power sources and energy storage systems capable of supplying the loads included in the microgrid.

Therefore, a microgrid acts as a single controllable entity relative to an overall network to which it can connect and disconnect. It has control, supervision and coordination capacity to achieve economic, technical and environmental objectives. This control capacity, along with the communications system necessary to implement it, is what turns a microgrid into an intelligent network, known within the sector as “smartgrid”.

Microgrids have obvious advantages over the use of traditional electricity production, transportation and distribution systems, among which can be found: improving the security and reliability of the electrical system; They can work coupled to the general network or in isolation; allows to supply areas where there is no electrical distribution; and reduce losses in the electrical system by generating, storing and using electricity locally.

It therefore seems that the electrical system model towards which we should tend is one based on the use of microgrids interconnected with each other through the conventional electrical system. Microgrids are typically connected to the distribution network through a direct connection or a converter that allows the microgrid to feed or inject energy into the general distribution network, depending on whether its production is less or more than its own consumption. In addition, it allows you to disconnect in case the general network presents problems and as required by the management of your own production and demand.

In this sense, there are well-known disclosures that reflect microgrids, mainly documents that attempt to control microgrids published in recent years. Among the known documents, the patent application US2021/0057909A1 stands out, which discloses an energy manager that acts on the loads located in its field of action, controlling their consumption based on different factors such as demand, electricity price and others. It includes generation systems such as photovoltaic panels or wind turbines whose power exchange with the grid also controls the invention, although this document only provides solutions for installations in residential buildings.

It is also known what is disclosed in document US9146548B2, which works like the previous antecedent, but in addition to executing the control of the data flow it receives, it has the ability to learn from this flow.

It is also known what was disclosed in document US20210149429A1, where energy aggregators are incorporated into the highest management layer to control the supply and sale of energy.

The three documents indicated, as well as all those known to the applicant, are applicable to homes and residential buildings and consist of controlling their energy consumption, each incorporating a capacity that improves the others. However, none of these known systems allow the electrical microgrid to participate in the power/frequency control of the power system (power system control - PSC) regardless of the size of that microgrid; and whether it is formed solely by thermal controllable loads (hereinafter TCL); formed by TCL and renewable energy generation systems (Renewable Energy Systems), hereinafter RES; formed by TCL, RES and energy storage systems (Energy Storage Systems) hereinafter ESS; formed only by only RES; or formed by RES and ESS.

The optimizing system proposed in the present invention, compared to any other known in the state of the art, comprises a control system that is applicable to microgrids formed from at least one of TCL, RES and ESS to, in addition to minimizing the overall consumption of the microgrid according to different parameters, such as the existing inventions listed above, solve the following problems in the field of the microgrid, such as:

(i) jointly manage the elements of the microgrid, even if they are connected to independent data networks, as would be the case of residential buildings.

(ii) make the power exchanged between the microgrid and the power system (PS) consist solely of fundamental active power, without other components that reduce the efficiency of this exchange, in the case of microgrids that contain RES and/or ESS; and

(iii) ensure that the microgrid can participate in the PSC with an amount of power that depends on the scope and size of each microgrid and applying different control strategies, depending on the elements that constitute it (TCL/RES/ESS).

In this sense, the applicant is not aware of any system that manages to solve the above problems.

It is true that, for the second problem or point (ii), one can think about optimizing the power exchange between the power system and a set of loads, so that the power exchanged is active, being able to use an active filter of power. However, there is no known system that integrates its functionality into microgrids and nor is there any device that performs both functions simultaneously and is also capable of alternating its operation between voltage source and intensity source, something that is achieved in the present invention. .

Another advantage of the present invention is that it can be applied not only to residential buildings, as is known to date, but to any type of industrial microgrid that contains TCL/RES/ESS, even if these elements are connected to different data networks. .

Thus, the system object of the present invention achieves, in addition to managing the exchange of energy with the PS, that this exchanged energy contains only fundamental active power and that the microgrid in which it has been implemented can participate in the PSC regardless of the constitution. of that microgrid.

EXPLANATION OF THE INVENTION

As previously mentioned, distributed generation and the growing penetration of renewable energy in the PS makes it necessary to restructure the known structures. A viable structure consists of the existence of many microgrids with the capacity to participate in the PSC and in the supply/demand balance. In the transition from the current model to this new PS we therefore find microgrids of different sizes, from those that contain only loads, among which we will highlight the TCL loads, to those that contain in addition to TCL, RES and/or ESS, passing through those that consist only of RES and/or ESS.

The present invention responds to this problem, and consists of a control system applicable to all these types of microgrids, which in addition to optimizing the efficiency of power exchange with the PS, enables its operation by participating in the PSC. In this sense, this system applicable to microgrids of different sizes optimizes their energy consumption both quantitatively and qualitatively, and makes it possible for the microgrid to participate in the control of the power system at the request of its operator, regardless of its composition. The system optimizes consumption by reducing the electric energy (EB) bill, from a quantitative and qualitative point of view, for which it is based on the fact that, although the microgrid contains loads that produce harmonics, the intensity exchanged with the electricity system power is sinusoidal. Therefore, compared to known systems, the present system achieves a qualitative optimization based on compensating the harmonic components of the intensity so that the power system (PS) sees the microgrid as a balanced sinusoidal load.

The system is applicable to a home without/with energy production or storage systems or to an industrial microgrid and can also be used with groups of homes in which the loads are connected to different data networks, as occurs in blocks of flats or urbanizations. Qualitative optimization consists of compensating the harmonic components of the intensity so that the power system sees the pred as a balanced sinusoidal load.

This system for optimizing the energy demand of electrical microgrids can include:

a supervisory device that contains the communications module that keeps permanently connected the elements that control the TCL, the RES and the ESS, or those present in each microgrid; and comprises a computer program or interface where the operation of the control system is managed and where the supervising user programs and establishes its operating parameters at all times;

an optimizing device that comprises a microprocessor with a computer program or algorithm that daily calculates the “on/off” sequence and the temperature that each TCL must follow, based on the electricity rate and meteorological data forecast for the next day and in depending on the operating parameters established by the supervisor through the interface; and a telematic control module that is responsible for guaranteeing that the temperature of the TCL follows the temperature sequence established by the algorithm in the previous point; and a plurality of temperature sensors and switches that connect and disconnect the TCLs;

an inverter that is responsible for transmitting the energy generated in the RES to the AC loads and/or to the electrical grid (if the microgrid contains RES); to compensate the harmonic components of the intensity consumed by the loads, so that the PS sees the microgrid as a balanced sinusoidal load, where this function of the inverter is carried out if the microgrid contains RES and/or ESS, although it does not contain TCL but only uncontrollable loads; and where the inverter supplies the non-sinusoidal component of the intensity required by the loads, so that, from the power system, the microgrid is seen as a linear load that consumes a sinusoidal intensity.

a DC/DC converter (hereinafter converters) for each RES existing in the microgrid, which controls the operating mode of the RES, distinguishing between its operation at the maximum power point (maximum power point) and MPP, or maintaining a determined reserve of active power; and where the mode of operation is determined by the parameters established by the supervisor and by the elements contained in the microgrid.

Going into greater detail of the invention, the supervisor device comprises a microprocessor card with an interface in which the owner/manager of the microgrid can establish the operating mode of the system (participating or not in the PSC). This parameter, together with the composition of the microgrid, determines the operating parameters of each component of the system. The interface also allows you to follow the operation of the system, since it can show or obtain the values of the different sensors and actuators of each of the components of the system and which, as detailed below, can be:

- Temperature values of the different spaces controlled by the TCLs.

- States of those TCLs, whether connected/disconnected;

- DC bus voltage value.

- Value of the different types of power (active and reactive) exchanged with the PS. - Values of the active power generated by the different RES.

- Values of the parameters that evaluate the quality of the wave in the intensity exchanged by the microgrid and the PS.

For its part, as previously mentioned, the communications module keeps all system components permanently connected, be it the inverter, the converters and/or the optimizing device.

For its part, the inverter has an internal structure that comprises a full-wave inverter made up of at least four insulated gate bipolar transistors or "IGBT transistors" with a transistor diode, which is a power element or stage; a circuit generating the firing orders of the previous power stage, based on the operation of a chip equipped with a response time shorter than that of the power stage itself; an LC filter as a conditioning circuit for the output wave of the power stage; a module for measuring the effective value of the output voltage; an input voltage measurement module; where the interface comprises two different reference signal generation algorithms: one of them generates a sinusoidal signal of 230 V effective and 50 Hz without the need for synchronization with the PS since it is the one used to generate the trigger signals of the IGBTs when the inverter works as a voltage source isolated from the PS; and another algorithm that generates a variable signal and that depends on the intensity required by the microgrid loads, in the following way: a signal is generated formed by the harmonic components of the intensity required by the microgrid loads and whose effective value fundamental varies so that the voltage of the DC bus to which the inverter will be connected is kept constant, where that second signal is synchronized with the voltage of the PS; So the inverter has the advantage over any known technology that the control module produces a wave that is the sum of a solenoidal wave and the harmonics contained in the load current.

As for the converters, these are DC/AC converters that include “boosts” (voltage boosters) and that include a microcontroller card and an interface with which IGBT trigger signals are generated so that an RES operates according to the parameters set in the interface. In addition, these converters also include an intensity sensor that measures the intensity generated by the RES system and another voltage sensor that measures its working voltage; and they also include a computer tool or control algorithm that calculates the voltage and intensity at which the RES system has to work.

As for the consumption optimizing device, this comprises two complementary control programs, the first that calculates the optimal temperature sequence for each space controlled by TCL, depending on the overall objective for the optimizer that has been imposed on the interface and the rate. expected for the following day, and also calculates the “on/off” sequence applicable to each TCL that achieves the above profile; and a second program that is responsible for guaranteeing that the temperature of each space controlled by TCL follows the previous profile, so that it controls the temperature at all times and, if the limit comfort temperature is exceeded, it acts by modifying the on/off sequence. established, until the temperature reaches that expected in the corresponding sequence.

On the other hand, the communications module of the supervision and control device, in possible embodiments of the invention, is such that it is configured for access to secure data networks that, being modular and scalable, are connectable with at least one connected secure network. with a plurality of physical equipment or plants accessible on a network and a non-secure public network accessible through a UI (Userinterface) module executable in a web browser and has the particularity of comprising at least one SCRA module ( Server to Control the Remote Access) which is a server configured to control access to a secure network with several sets of physical equipment or plants, all of them accessible on the network; which can also replace a SCRA module with a CPD module (Cloud Publishing Device), which is an electronic device configured to connect to a secure network with access to converged physical equipment that constitutes a group or plant; and configured to request publication in a CPS module (CloudPublishing Server) is a server configured to make publishing requests made by the CPD module or modules visible from the non-secure public network.

The present invention allows a microgrid to also operate without participating in the PSC, establishing as the setpoint voltage of the DC bus the maximum value supported by the ESS, if it exists. Furthermore, the RES would work in their respective MPP and the consumption optimizer would work by minimizing the electric energy bill (EB) if there is no ESS, or minimizing consumption otherwise.

In this sense, the applicant does not know of any device that can make a microgrid work by participating or not in the PSC (at the choice of its manager) regardless of the elements that compose it, something that is proposed in the present invention. And there is no known system applied to microgrids that, in addition, works as an active power filter whenever the microgrid works connected to the PS and that also allows the inverter to manage the connection/disconnection of the microgrid with the PS. Furthermore, compared to any system known in the state of the art, the field of action of the present invention is not limited to residential buildings, but also works in business or industrial facilities with any of the TCL/RES/ESS elements.

It must be taken into account that, throughout the description and claims, the term "comprises" and its variants are not intended to exclude other technical characteristics or additional elements.

BRIEF DESCRIPTION OF THE FIGURES

In order to complete the description and to help a better understanding of the characteristics of the invention, a set of figures and drawings is presented where the following is represented, for illustrative and non-limiting purposes:

Figure 1.- Shows the diagram of the optimizing system object of the present invention when the microgrid comprises TCLs, an RES and an ESS, therefore it comprises a supervisor device (1), an optimizing device (4), an inverter (2), and some converters (3); the latter being connected with a common DC direct current bus (5); and where an inverter is connected to that bus, which is responsible for supplying power to the loads, exchanging energy with the PS, compensating for the harmonic components of the load intensity and managing the connection/disconnection of the PS; where the inverter is in turn connected to the PS and the loads; and where the microgrid comprises TCL representing residential and industrial loads.

Figure 2.- Shows the diagram of the optimizing system for the case in which the microgrid is made up of RES and ESS.

Figure 3.- Shows the diagram of the optimizing system for the case in which the microgrid is made up of TCL and RES.

Figure 4.- Shows the diagram of the optimizing system for the case in which the microgrid is made up of loads, among which the TCL stands out, such as the loads of current conventional homes and buildings.

Figure 5.- Shows the diagram of the optimizing system for the case in which the microgrid is made up of RES.

Figure 6.- Shows a diagram of the qualitative optimization of microgrid consumption, where some loads (AC loads) are connected to the PS. These loads produce harmonics that mean that the intensity they consume is not sinusoidal (iload). By connecting a DC/AC converter between the PS and the loads, this converter can generate the non-sinusoidal part of the intensity required by the loads (iinv), so that the intensity required by the set of both devices, and which has to supply the PS, is sinusoidal (<sp>), and where the element is represented by a computer operating tool (F) controlled by its corresponding computer control tool (C) to which the values of the voltages and intensities continuously arrive. necessary for its correct functioning

DESCRIPTION OF SOME MODES OF CARRYING OUT THE INVENTION

As can be seen in the previous set of figures, some possible embodiments of the system object of the invention are detailed below.

Specifically, Fig. 1 shows the system operating in a complete microgrid, which includes TCL, RES and ESS, where the RES and ESS are connected to a common direct current bus (5) through separate converters (3). ). The inverter (2) is also connected to that DC bus, it interfaces with the PS and supplies power to the loads. In this case, the system includes

a supervisory device (1) that contains the communications module that keeps permanently connected the elements that control the TCL, the RES and the ESS, or those present in each microgrid; and comprises a computer program or interface where the operation of the control system is managed and where the supervising user programs and establishes its operating parameters at all times;

an optimizing device (4) that comprises a microprocessor with a computer program or algorithm that daily calculates the “on/off” sequence and the temperature that each TCL must follow, based on the electricity rate and weather data forecast for the day following and depending on the operating parameters established by the supervisor through the interface; and a telematic control module that is responsible for guaranteeing that the temperature of the TCL follows the temperature sequence established by the algorithm in the previous point; and a plurality of temperature sensors and switches that connect and disconnect the TCLs;

an inverter (2) that is responsible for transmitting the energy generated in the RES to the AC loads and/or to the electrical grid; to compensate the harmonic components of the intensity consumed by the loads, so that the PS sees the microgrid as a balanced sinusoidal load; and where the inverter supplies the non-sinusoidal component of the intensity required by the loads, so that, from the power system, the microgrid is seen as a linear load that consumes a sinusoidal intensity, and that manages the connections/disconnections of the microgrid and the PS; and

some converters (3) for each RES existing in the microgrid, which control the mode of operation of the RES, distinguishing between their operation in the MPP, or maintaining a specific reserve of active power; and where the mode of operation is determined by the parameters established by the supervisor and by the elements contained in the microgrid.

Figure 2 shows another possible embodiment example where there is a system in which the microgrid is made up of RES and ESS; therefore, it comprises a supervisory device (1); an inverter (2) and converters (3) for each RES existing in the microgrid, and where the RES and the ESS are connected to a bus (5).

Figure 3 shows an example of embodiment of the invention where there is a system in which the microgrid is formed by TCL and RES; therefore, it comprises a supervisory device (1); an optimizing device (4) for the TCL, an inverter (2) and converters (3) for each RES existing in the microgrid.

Figure 4 shows another example of a possible embodiment of the invention where the optimizing system is used for the case in which the microgrid is made up of loads, among which the TCL stands out, such as the loads of current conventional homes and buildings.

Finally, Figure 5 shows an example of carrying out the invention where there is an optimizing system for the case in which the microgrid is made up of RES.

As can be seen, the present invention, compared to the technologies known in the state of the art, can be applied not only to residential buildings as is known to date, but to any type of industrial microgrid that contains TCL/RES/ESS, even if those elements are connected to different data networks.

In this sense, the functions of the converters (3) are the following: keep each RES working at its MPP or with an active power reserve, depending on the operating mode established by the supervisory device (1); disconnect the RES from the DC bus (5) if the voltage therein rises with respect to the setpoint voltage above a value that will also be established by the supervisory device; and the DC bus voltage is also established by the supervisory device depending on the operating mode.

Regarding the inverter (2), its functions depend on whether the microgrid is connected to the PS or not and are as follows:

- if the microgrid is connected to the SP. In this case, the inverter works as a current source and its objectives are: to inject power to the loads and/or to the SP, for which it will work as a current source, maintaining the DC bus (5) voltage at the established value. by the supervisory device (1); compensate the harmonics of the intensity required by the loads so that the intensity exchanged by the network and the PS is sinusoidal, that is, it works as an active power filter; remain attentive to the PS voltage to function as a voltage source in the event of its disconnection.

- if the microgrid is not connected to the SP. In this case, the inverter functions as a voltage source and its objectives are: to supply power to the microgrid loads; disconnect when the DC bus (5) voltage rises or falls with respect to the setpoint voltage above the value established by the supervisory device; Stay attentive to the PS signal to synchronize and connect when it is available.

With respect to the consumption optimizing device (4), it is responsible for controlling the operation of the TCLs if they exist in the microgrid, as described above.

The general operation is described below based on the parameters established by the supervisory device (1), where it is stable whether the PSC is participated or not.

In the event that the supervisory device (1) establishes that it does not participate in the PSC.

A) The microgrid is made up of one or several buildings with loads, including several TCLs, all connected to the same data network or to different data networks. In this case, the optimizing device (4) calculates the temperature profile that reduces the electric energy bill (EB) for each of the TCL and the “on/off” sequence of the corresponding thermal equipment. This calculation is carried out daily by the optimizing device based on a model of each TCL, the data on irradiance, temperature, cloudiness and the electricity rate for the next day. Before starting the day in question, you already have the sequence to follow. From there, the optimizing device is dedicated solely to monitoring that the TCL temperatures do not deviate from the setpoint beyond a value determined by the supervisory device. Note that, in this case, the microgrid has to be continuously connected to the PS and if a zero voltage occurs, the optimizing device (4) can do nothing but wait for it to be corrected. This embodiment example corresponds to the one presented in Figure 4.

B) The microgrid is made up of loads, among which are the TCLs and also one or more RES. The operation with respect to the TCL is as previously described, except that in the calculation of the “on/off” sequence of the TCL, the optimizing device (4) takes into account the production profile of the RES. The non-participation of the microgrid in the PSC requires that the RES work at all times in their MPP. The inverter (2), which functions in these circumstances as a current source, acts, in addition to injecting the power produced by the RES into the PS, as an active power filter, compensating for the harmonics produced by the loads connected to the grid in a that the intensity at the input of the qgrid, which the PS must provide, is sinusoidal. In case of PS failure, the converter (3) begins to function as a voltage source, using the power generated in the RES to supply the loads, as long as possible. This embodiment example corresponds to the one presented in Figure 3.

C) If the microgrid is made up only of RES, its operation in the case of non-participation in the PSC would be as described in the previous case without the part corresponding to the TCL. This embodiment example corresponds to the one presented in Figure 5.

D) When the microgrid is made up of TCL, RES and ESS loads, such as the example embodiment in Figure 1, in this case, the temperature profile calculated for the TCL by the optimizing device (4) varies because it is no longer treated of reducing EB but of reducing their total consumption. Apart from that, the operation of the consumption optimizing device (4) is the same as in the previous points. In a microgrid that contains these elements and without participation in the PSC, the voltage on the DC bus (5) will be the maximum that can be supported by the ESS to keep it always charged. The RES always work in their MPP. In this case, two operating possibilities are open: 1.D.1. With the microgrid always connected to the PS. The inverter (2) works as a current source and as an active power filter, compensating for load harmonics. If a voltage zero occurs, the converter (3) begins to function as a voltage source, as long as the battery can supply the necessary power, that is, as long as the voltage on the DC bus (5) remains above its value. minimum. If this voltage is reached, the inverter (2) cuts off the supply until it rises again or the SP signal returns. If this second happens, the converter (3) synchronizes and starts working again as a current source and active power filter.

1.D.2. With the microgrid isolated and connecting once a day to replenish the ESS load. In this case, the inverter (2) works as a voltage source. The supervisory device (1) determines the daily connection time with the PS so that it is during off-peak hours in the event that the ESS needs to be recharged and during peak hours otherwise. During the connection time with the PS, the inverter works as a current source and as an active power filter if it has to inject power into the grid or as a rectifier if it has to take it.

E) If the microgrid is made up of RES/ESS, like the one shown in Figure 2, with operation as described in the previous point without the part corresponding to the TCL.

The supervisory device (1) establishes that you do participate in the PSC.

F) An example of implementation in a system like the one shown in Figure 4.

The operation of the supervisory device (1) with respect to the TCL is as described in point A; However, in addition to that, the supervisory device remains attentive to the instructions of the PS operator (powersystem operator), hereinafter PSO. In the event that the PSO requires a decrease in consumption or an increase in generation, the optimizing device (4) disconnects all the TCLs, which are connected as they reach the non-comfort temperature and remain "on" until the corresponding temperature is reached. at that moment of the setpoint temperature profile established the previous day. If the PSO requires an increase in consumption, the optimizing device (4) connects all the TCLs. From there, the operation of the system is analogous to that explained previously in the. point A, where the microgrid has to be continuously connected to the PS.

G) The microgrid is made up of TCL loads and RES, as in the example embodiment in Figure 3. The operation with respect to the TCL is as described in the previous point, except that in the calculation of the “on/ off' of the TCL, the optimizing device (4) takes into account the production profile of the RES. The RES work at a certain point, different from the MPP so that they can increase or decrease generation according to the requirements of the PSO. The behavior of the TCL with respect to the PSO continues to be as described in the previous point. The inverter (2), which functions in these circumstances as a current source, acts, in addition to injecting the power produced by the RES into the PS, as an active power filter, compensating for the harmonics produced by the loads connected to the pred in a that the intensity at the input of the pred and that the PS must provide will be sinusoidal. In case of PS failure, the converter (3) begins to function as a voltage source, using the power generated in the RES to supply the loads, as long as possible.

H) The control described in the previous point can be applied, ignoring the TCL issues, to a microgrid formed solely by RES, such as the one shown in Figure 5.

I) When the microgrid is made up of TCL, RES and ESS loads, in this case, the optimizing device (4) calculates the temperature profile of the TCL that minimizes its consumption (and not the EB). Apart from that, the operation of the optimizing device is the same as in the previous sections. In a microgrid that contains these elements participating in the PSC, the voltage on the DC bus (5) is the nominal voltage of the ESS so that it can increase and decrease electrical generation at the request of the PSO. The RES always work in their MPP. In this case, two operating possibilities are open:

1.I.1. With the microgrid always connected to the PS. The inverter (2) works as a current source and as an active power filter, compensating for load harmonics. If the PSO needs to reduce consumption or increase generation, the setpoint voltage of the DC bus (5) becomes the minimum supportable by the ESS, until the need disappears. Otherwise, this DC voltage becomes the maximum supportable by the ESS. If a zero voltage occurs, the inverter (2) begins to function as a voltage source, as long as the battery can supply the necessary power, that is, as long as the voltage on the DC bus (5) remains above its value. minimum. If this voltage is reached, the inverter (2) cuts off the supply until it rises again or the SP signal returns. If this second happens, the inverter (2) synchronizes and starts working again as a current source and active power filter.

1.I.2. With the microgrid isolated and connecting once a day to replenish the ESS load. In this case, the inverter (2) works as a voltage source. The supervisory device (1) determines the daily connection time with the PS so that it will be during off-peak hours when the ESS needs to be recharged and during peak hours otherwise. During the connection time with the PS, the inverter (2) works as a current source and as an active power filter if it has to inject power into the grid or as a rectifier if it has to take it. In this case, at the request of the PSO, the supervisory device connects the qnet and works to decrease or increase consumption, as required by the PSO.

J) The control described in the previous section can be applied to a microgrid formed by RES/ESS, such as the one presented in Figure 2, if the TCL is ignored.

Claims (7)

1. - Energy demand optimizing system for electrical microgrids, with which the power exchange with the power system (PS) is managed and participates in the power/frequency control of the power system (PSC), comprising the microgrid at least an element selected from thermal controllable loads (TCL), renewable energy generation systems (RES), energy storage systems (ESS) or a combination thereof; which is characterized by it comprises a supervisory device (1) that is in connection with at least one element selected from an inverter (2), a converter (3) and an optimizing device (4); where the supervisor device (1) comprises a communications module that keeps the elements present in the microgrid connected, and comprises a computer program or system management interface and where a supervisor user programs and establishes operating parameters, and where the device supervisor establishes whether or not to participate in the PSC; where the optimizing device (4) is a TCL management element; and where the inverter (2) is a management element of the RES and/or ESS, where the converter (3) is a management element of the RES, the RES and the ESS being connected to a common current bus (5). keep going. 2. - Energy demand optimizer system for electrical microgrids, according to claim 1, wherein the communications module of the supervisory device (1) is connectable with at least one secure network connected to a plurality of physical equipment or plants accessible on the network and a non-secure public network accessible through a UI (User Interface) module executable in a web browser, and comprising at least one module selected from a SCRA (Server to Control the Remote Access) module configured to control the access to a secure network with several sets of plant equipment, all of which are network accessible; a CPD (Cloud Publishing Device) module connected to a secure network with access to converged physical equipment that constitutes a group or plant; and configured to request publishing in a CPS module (CloudPublishing Server) configured to make publishing requests made by the CPD module or modules visible from the non-secure public network. 3. - Energy demand optimizer system for electrical microgrids, according to claim 1, wherein the inverter (2) has an internal structure that comprises a full wave inverter consisting of at least four insulated gate bipolar transistors or "IGBT transistors" with transistor diode, which is a power element or stage; a circuit generating the firing orders of the previous power stage, based on the operation of a chip equipped with a response time shorter than that of the power stage itself; an LC filter as a conditioning circuit for the output wave of the power stage; a control module that regulates the different parameters of the output signal; a module for measuring the effective value of the output voltage; an input voltage measurement module; and an operation control monitoring module. 4. - Energy demand optimizer system for electrical microgrids, according to claim 3, where the interface comprises two different reference signal generation algorithms: one of them generates a sinusoidal signal of 230 V effective and 50 Hz without the need for synchronization with the PS; and another algorithm that generates a variable signal that depends on the intensity required by the microgrid loads. 5. - Energy demand optimizing system for electrical microgrids, according to claim 1, where the converters (3) are DC/DC converters that comprise voltage boosters, a microcontroller card and at least one computer tool or interface, and, at least, an intensity sensor that measures the intensity generated by each RES and another voltage sensor that measures the working voltage of that RES. 6. - Energy demand optimizer system for electrical microgrids, according to claim 5, where there is a computer tool for managing the operation of the RES, and a computer control tool that calculates the voltage and intensity at which the RES has to work. . 7. - Energy demand optimizing system for electrical microgrids, according to claim 1, wherein the optimizing device (4) comprises a microprocessor with two computer programs or interfaces in connection with at least one sensor and/or actuator located in each TCL of the system. , where the first program calculates the on/off sequence of each TCL and the second controls the temperature of each TCL at all times.