BR112020007686A2 - balanced energy storage balance technology - Google Patents

Abstract

The present invention relates to an energy storage system that comprises an energy reservoir and a system controller. The power reservoir is charged with DC power from a DC power source during discharge of DC power to a DC / AC converter. A system controller regulates the DC energy discharged from the energy reservoir to the DC / AC converter to almost balance the amount of DC energy charged in the energy reservoir. Since this loading and unloading is almost balanced, the size of the energy reservoir can be quite small in relation to the amount of loading and unloading. This is advantageous where the charge and discharge flow is high, as may be the case if the energy reservoir receives charge from all or a substantial portion of a power plant, such as a solar power plant. With such a controller the use of an energy reservoir becomes technically feasible even with these large current flows.

Description

"CONTROLLED ENERGY STORAGE BALANCE TECHNOLOGY" BACKGROUND

[001] Photovoltaic power plants (PV) generate electricity by converting solar energy into electricity. This generated electricity is then supplied to an electrical grid. The source of solar energy (that is, the rays received from the sun) is characterized as having a varying intensity over time. Therefore, the photovoltaic electric generators in such PV power plants incorporate a power generation optimization device (also known as an “optimizer”). One type of optimizer is called a “maximum power point tracker” (MPPT) (or “MPPT device”), which tracks an instantaneous voltage from the maximum power production point (MPPP) that the MPPT device uses to control the operation of the PV power plant. This practice is referred to as “blind MPPT conformation” in this document. The MPPT device is usually software or firmware; and tracks time-varying voltage, resulting in maximum power output from the time-varying solar energy source.

[002] The object claimed here is not limited to modalities that solve any disadvantages or that operate only in environments such as those described above. Instead, this Foundation section is provided only to illustrate an area of exemplary technology where some modalities described in this document can be practiced.

BRIEF SUMMARY

[003] The modalities described in this document refer to an energy storage system that comprises an energy reservoir and a system controller. The power reservoir is charged with DC power from a DC power source during discharge of DC power to a DC / AC converter. A system controller regulates the DC energy discharged from the energy reservoir to the DC / AC converter to almost balance the amount of DC energy charged in the energy reservoir. Since this loading and unloading is almost balanced, the size of the energy reservoir can be quite small in relation to the amount of loading and unloading. This is advantageous where the charge and discharge flow is high, as may be the case if the energy reservoir receives charge from all or a substantial portion of a power plant, such as a solar power plant. With such a controller, the use of an energy reservoir becomes technically feasible even with these large current flows.

[004] The system controller comprises a detection component, a determination component and a delivery component, the detection component is configured to measure a level of energy stored in the energy reservoir. The determination component is configured to use the measured level of stored energy from the energy level to assess whether an adjustment should be made. The delivery component is configured to encode the instruction to perform the adjustment on a coded message when the determination component determines that the adjustment must be made, and is also configured to deliver the encoded message to the CC / AC converter.

[005] This Summary is provided to introduce a selection of concepts in a simplified way, which are described later in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed object, nor is it intended to be used as an aid in determining the scope of the claimed object.

BRIEF DESCRIPTION OF THE DRAWINGS

[006] In order to describe the way in which the above mentioned advantages and resources and others can be obtained, a more particular description of various modalities will be provided by reference to the accompanying drawings. Understanding that these drawings represent only sample modalities and, therefore, should not be considered limiting the scope of the invention, the modalities will be described and explained with specificity and additional details through the use of the attached drawings, in which:

[007] Figures 1A to 1C illustrate block diagrams of several power plants in which decoupling devices are used in conjunction with an energy reservoir;

[008] Figure 2A illustrates a block diagram of a power plant that was configured in an experiment, and in which there are two AC power production units that are configured in a conventional way, and with power and energy meters that measure the output from each power production unit;

[009] Figure 2B illustrates a block diagram of the power plant of Figure 2A after modification to include decoupling devices and an energy reservoir, and which was used to verify better energy output to the grid;

[010] Figure 3 illustrates a block diagram of a power plant in which there are two channels of power delivery, one channel invoking the use of an energy reservoir, and one not invoking the use of the energy reservoir;

[011] Figure 4 illustrates a block diagram of a power plant that represents a broader modality in Figure 3;

[012] Figure 5 illustrates a block diagram of a power plant in which power is delivered through the use of an energy reservoir;

[013] Figure 6 illustrates a block diagram of a power plant that represents a broader modality in Figure 5;

[014] Figure 7 illustrates a block diagram of a power plant;

[015] Figure 8 illustrates a block diagram of a Maximum Energy Utilization Point Tracking (MEUPT) controller according to the principles described in this document; and

[016] Figure 9 illustrates a block diagram of the MEUPT controller from

Figure 8 in the context of a power plant.

DETAILED DESCRIPTION

[017] Patent publications US2016 / 0036232 and US2017 / 0149250 A1 (whose content is incorporated by reference) disclose that PV power systems that practice blind MPPT conformation achieve suboptimal amounts of electricity supplied to the grid. These patent publications teach that, in order to efficiently extract electricity for energy use, the characteristics of the energy extraction device must be combined to effectively and efficiently extract the electrical energy produced. In addition, these patent applications teach that the related devices must also be combined to condition and / or deliver the extracted electricity for energy efficient use.

[018] These patent publications further emphasize the fact that energy use efficiency is inextricably dependent on energy demand, in addition to power production. Furthermore, they teach that, in any energy system, typical power consumption is not necessarily equal to power production, even when complying with energy and load conservation laws.

[019] Instead of using the MPPT device as the optimizer for solar power plants, the aforementioned patent publications proposed to use a “maximum energy usage point tracker”, or the “MEUPT device” as the PV power plant optimizer. . Such an optimizer will be referred to as a “MEUPT optimizer” in this document. According to the referenced patent publications, the MEUPT optimizer is designed to capture what is referred to as “surplus energy”, which is defined as the electrical energy that is produced, but not extracted and / or delivered to the grid for use. Such a definition of “surplus energy” is also used in this document.

[020] The MEUPT optimizer is also designed to temporarily store the excess energy captured within an energy reservoir; and then prepare and deliver that electricity to the grid for use. In this way, the electricity sales revenue of the PV power plant can be improved by incorporating the MEUPT optimizer.

Section One: MEUPT optimizer functionality

[021] In accordance with the principles described in US2016 / 0036232 and US2017 / 0149250 A1 (the “referenced patent publications”), the MEUPT optimizer of a modality disclosed in this document comprises an excess energy extractor, an energy reservoir and a MEUPT controller. The MEUPT controller works in conjunction with power extractors and DC / AC converters. The terms "power" and "energy" (although not exactly the same) are used interchangeably in the technique. Thus, unless otherwise specified, each term has the same meaning.

[022] A power extractor extracts an initial oscillating power train from the produced DC electrical power source. The extracted initial power chain adapts to the AC mains requirements of the mains. In other words, the extracted initial power chain has a time-varying sinusoidal voltage having a peak voltage that adapts to the voltage range of the power grid. In addition, the electrical power (which is proportional to the square of the voltage) takes the form (sin? (Wt) or cos? (Wt)), which is synchronized (with the same phase and the same frequency) with the electrical network.

[023] On the other hand, an excess energy extractor extracts a remaining oscillating power train that remains from the subtraction of the initial oscillating power train from the produced DC power. In other words, this remaining oscillating power train is a remaining oscillating power train that remains after providing the initial oscillating power train to the power grid. The remaining oscillating power train has a phase shift of 90º compared to the initial oscillating power train that was supplied to the power grid. Due to the 90º phase shift, this remaining oscillating power train cannot be immediately converted into AC power for supply to the same electrical network. An energy reservoir is thus used to temporarily store the surplus energy from the remaining oscillating power train. Afterwards, the stored energy is supplied to a DC / AC converter; such that the surplus stored energy can be converted into AC power, which is synchronized (with the same phase and frequency with the same electrical network.

[024] The MEUPT controller measures the energy level of the reservoir; estimates the amount of energy in the reservoir that can be extracted; and delivers that information to the associated DC / AC converter (s), such that that amount of energy can be extracted by the DC / AC converter (s). The DC / AC converter (s) then extract (s) the stored energy from the reservoir for conversion to AC power in the form of a suitable pulsating power train and provide AC power to the mains. PV power plants can thus supply almost all the electrical energy produced to the power grid by incorporating the MEUPT optimizer. In contrast, without the MEUPT optimizer, the PV power plant according to the aforementioned patent publications can only supply less than half of the power / energy produced to the power grid.

Section Two: Improving conventional PV power plant with MEUPT

[025] Solar power plants are generally classified in terms of some number of MegaWatts (MW). Conventionally, when a solar power plant is declared rated at x MW (where x is some positive number), this means that the sum total of the DC power production rating for all solar chains is x MW. Such conventional solar power plants also have three-phase DC / AC converters with a total DC / AC conversion capacity declared by the manufacturer that is not more than x MW. This principle summarizes the operations of conventional power plants according to conventional MPPT practice.

[026] In other words, the conventional x MW rated PV power plant consists of chains of x MW PV solar panels, which convert solar energy into DC electricity. The generated DC electricity is then extracted and converted by three-phase DC / AC converters into suitable AC electrical power that adapts to all the AC power requirements of an electrical network, and is then supplied to the electrical network. This AC electrical power supplied to the electrical network is also referred to in this document as the “initial oscillating power train”. It is recalled that the total DC / AC conversion capacity declared by the manufacturer of the DC / AC converters is not more than x MW, which is the total amount of DC generation capacity of the installed solar panels declared by the solar panel industry.

[027] According to the description of the referred patent publications, US2016 / 0036232 and US2017 / 0149250 A1, there is a remaining oscillating power train that results in subtracting the initial oscillating power train (extracted by the power extractor) from the DC power total produced by the solar panel chains. In other words, this power train is the remaining oscillating power train that has a phase difference of about 90º from the initial oscillating power train that was extracted by the power extractor and supplied to the power grid.

[028] As the remaining oscillating power train is lagged by about 90º from the electrical network, this remaining oscillating power train cannot be directly conditioned and converted into AC power and supplied to the same electrical network. According to the principles disclosed in the aforementioned patent publications, an energy reservoir temporarily stores the energy contained in this remaining oscillating power train lagged 90º (which when stored represents the surplus energy). After that surplus energy is stored in the energy reservoir, the surplus energy can serve as the DC energy that can be supplied to a DC / AC converter. This surplus energy can then be converted into an AC power that adapts to all the requirements of the electrical network (including synchronization with the electrical network), such that the resulting AC power can be supplied to the same network.

Section Three: Prevent energy leakage from the energy reservoir

[029] Before elaborating on the consideration of the project energy reservoir for the MEUPT optimizer, an important subject is first addressed in this document. Specifically, solar panel chains can have a very high resistance at dusk, but the solar panel chain can conduct significant electrical current in any direction, when the sun is strong at noon. Therefore, the electrical energy stored in the reservoir can leak and heat the solar panels during the day. Therefore, decoupling diodes can be added to each chain of solar panels, such that electrical energy can flow from each chain of solar panels to charge the reservoir, but the energy in the reservoir cannot return the flow from the reservoir to the chains. solar panel. Various energy reservoir systems that perform this decoupling will now be described with reference to Figures 1A, 1B and 1C.

Section Four: Design considerations for the energy reservoir

[030] Figure 1A shows a block diagram illustrating a 1300A energy reservoir that is designed to temporarily store the excess power resulting from a power flow produced from a set of 1100A solar chains by subtracting the power extracted by a DC / converter AC 1200A when the DC / AC 1200A converter converts that power into AC power. AC power is supplied to an AC 1600A mains via a 1500A transformer. The 1300A reservoir receives the remaining oscillating power train through a 1400A decoupling diode assembly. In one example, this 1300A energy reservoir is designed to temporarily store surplus energy from a 1 MW PV power plant for 2 minutes.

[031] Just as an example, suppose that the primary energy source can maintain constant intensity (and that the energy production of PV 1100A chains is maintained, in order to allow a constant production of generator power of 1 MW) for 2 minutes . For the following analysis, both the initial and remaining oscillating power trains have the same repetition forms, but with a 90 degree phase difference. First, let's examine how the energy reservoir can be designed using brute force. Remember that the purpose of the energy reservoir is to temporarily store surplus energy so that DC / AC converters can later convert that stored energy.

[032] As discussed in the referenced patent publications, the estimated proportion of surplus energy to the produced DC electrical energy is greater than 0.5 for typical conventional PV power plants. For analysis, let's assume that the PV power plant has 1 MW PV solar panel chains; and the DC power is converted to AC power to supply a 50 hertz network and three-phase AC power with a 380 V line voltage. In this case, the duration of a power cycle is about 0.01 second and the total phase current is up to

1,000,000 / (380 / 1,732), where 1,732 is the square root value of 3. This ratio is the ratio of peak voltage to line voltage (line-to-phase voltage, or “phase voltage”, in power Three-phase AC). Storing the load associate with the surplus energy in a power cycle for that power station would require an equivalent load capacity of approximately 8 V Faraday (05 * 0.01 *

1,000,000 / (380 / 1,732)), where “V” is the voltage difference of the designed tank before and after loading.

[033] To maximize the energy utilization of this PV station, in some modalities, the operating voltage of the MEUPT optimizer must be within 75% of the maximum PV power production voltage. In other words, the voltage range of the maximum power output of 75% is observed in the MEUPT optimizer modes. The measured | -V data indicates that this range is typically around 80 volts. When this voltage range is chosen as the charging / discharging voltage range (ie, V = 80 volts) for the energy reservoir, the charging capacity of an energy reservoir is about 0.1 Faradays per MW , per power cycle (where the power cycle lasts 0.01 seconds).

[034] If the design consideration is to store that maximum amount of excess energy accumulating for two (2) minutes, the equivalent load capacity required is equal to 1200 Faradays (100 * 120 * 0.1) for the PV power plant of 1 MW. This required equivalent load capacity is referred to as the “total maximum load capacity” and the amount of energy stored in the associated reservoir is referred to as the “total maximum energy reservoir capacity” or “total maximum excess energy” in this document.

[035] If only thin-film capacitors were used to meet the required charging capacity, the set of thin-film capacitors needed to achieve the charging capacity would be prohibitively large in volume and very expensive. Thus, it is not practical to design an energy reservoir that consists only of thin film capacitors.

[036] As a turning point in brute force design, it is possible to incorporate Faraday devices (such as batteries) into the design to reduce volume and size. The inventors' careful analysis reveals that the required charge capacitance is in fact technically manageable for an energy reservoir with thin film capacitors and Faraday devices. However, the cost of this reservoir is still too high to be beneficial, unless the battery price can be reduced by at least a factor of 3, while maintaining the same performance.

[037] The use of electrolytic capacitors can substantially reduce the cost of capital required. However, this would increase the cost of operation due to the relatively short life of such capacitors. Thus, currently, the use of electrolytic capacitors is also not practical. Therefore, brute force does not reach economically beneficial projects with the total capacity of the reservoir of maximum energy required.

[038] The principles described in this document use the following facts observed by the inventors to solve this problem: (1) Most existing DC / AC converters can easily increase or decrease power by 3% in one second; and the existing 500 kW DC / AC converters can easily increase or decrease more than 10 kW in one second during operation.

(2) As a preliminary observation, a typical 1 MW PV power plant starts producing power from zero power every morning and rarely increases its power production faster than 10 kW / second in its normal daily operation.

(3) A PV power plant at the MW level (rated greater than 1 MW) may occasionally experience an increase rate greater than 10 kW per second during a short burst of power. However, the energy contained in that short burst (or even in bursts greater than 100 kW per second) is insignificant when compared to the total daily energy produced in power plants at the MW level.

[039] From these three facts, the inventors determined that (1) the power generation in each of the solar panel chains starts from scratch every morning; and (2) the PV generator does not generate full power instantly. This way, the remaining oscillating power train does not increase to its maximum value instantly. In other words, the remaining oscillating power train typically increases much more smoothly than the acceleration rate of DC / AC converters. In addition, the amount of energy in any burst of acceleration is not a significant problem in collecting energy for PV plants rated 1 MW or higher.

[040] Therefore, instead of designing a reservoir of energy capable of storing the maximum total amount of surplus energy, the principles described in this document suggest designing a reservoir to store the amount of net energy equal (say, 2 minutes) to the difference between the excess energy inserted in the reservoir, and the energy that the DC / AC converter (s) extracted from the reservoir. This amount of energy is referred to as the “maximum differential excess energy” in this document. This amount of maximum differential surplus energy is much less than the maximum total surplus energy. It is thus easier to design such a smaller energy reservoir; which has manageable technology and is also economical.

[041] Figure 1B presents a block diagram that symbolically illustrates a 1300B energy reservoir that stores surplus power resulting from a power flow produced from a set of 1100B solar chains by subtracting the power extracted by a 1201B DC / AC converter. At the same time, another 1202B DC / AC converter is driven by the MEUPT 1310B controller to receive approximately the same amount of DC energy from the 1300B energy reservoir (containing the surplus power). Both 1201B and 1202B DC / AC converters simultaneously convert the received DC power into AC power, and supply that AC power to the same 1600B network through the same 1500B transformer. In doing so, the net energy storage load for the 1300B reservoir can be reduced to a very small capacity when compared to that of the 1300A reservoir shown in Figure 1A.

[042] Figure 1C shows a configuration that is modified from the configuration shown in Figure 1B, but has approximately the same performance as the configuration shown in Figure 1B. As shown in Figure 1C, a 1300C energy reservoir stores the DC power flow produced by PV 1100C solar chains through a 1400C diode array. Two 1201C and 1202C DC / AC converters are directed by the MEUPT 1310C controller to receive (in the aggregate) approximately the same total DC power from the 1300C energy reservoir in an amount approximately equal to the inserted DC energy produced by the PV chains. Thus, there is only a very small net power input balance at the 1300C reservoir inlets and outlets. Both 1201C and 1202C simultaneously convert the received DC power into AC power supplied to the same 1600B network via the same 1500C transformer.

[043] In short, as shown in Figure 1B (when properly decoupled) the power reservoir can extract and store surplus energy in the form of a remaining oscillating power train that remains after the produced DC power is extracted by an energy extractor (which can be embedded as a 1201B DC / AC converter module). The other 1201B DC / AC converter is designed to draw an approximately equal amount of energy from the 1300B energy reservoir to reduce the net amount of excess energy stored in the reservoir. Thus, a relatively small reservoir is suitable.

[044] Also as shown in Figure 1C, (when properly decoupled) the 1300C energy reservoir can receive all the DC power produced from the 1100C PV chains. An oscillating power train is then extracted by the DC / AC converters 1201C and 1202C, while the surplus energy (the remaining power) is also implicitly stored inside the 1300C energy reservoir in the form of an oscillating power train lagging 90º. As can be seen, this surplus energy is also implicitly extracted automatically and stored in the 1300C reservoir.

[045] Applying the design shown in Figure 1B (or Figure 1C), the projected energy reservoir can serve as the energy reservoir for a MEUPT optimizer; which temporarily stores a small amount of net surplus energy that is 90º out of phase. The difficult task of designing the energy reservoir is now shifted to the task of designing a suitable MEUPT controller.

Section 5: Necessary functions of the MEUPT controller

[046] The controller must be able to direct the associated DC / AC converters to consistently extract an adequate amount of energy from the reservoir that is substantially equal to the amount of excess power loading in the reservoir. By doing this, you can minimize the net amount of energy storage in the reservoir; and maintaining adequate balanced energy storage in the reservoir to stabilize the system's operation. In doing so, the energy reservoir only needs to store (or supply) the energy difference between the excess load power and the power extracted by the DC / AC converter (s) within a short time.

[047] With a suitable controller, the power difference can be designed to be manageable small. The duration of time can be designed to be long enough to increase or decrease the DC / AC converter (s) in correspondence of the surplus energy; and short enough to significantly reduce reservoir capacity, while keeping system operation stable. The estimated capacity of the reservoir can therefore reduce to less than 0.001 times the maximum total surplus energy. This capacity is less than 2 Faradays per 1 MW PV power plant; manageable charging capacity even when using thin film capacitors. An example of a suitable MEUPT controller will be described with respect to sections Twelve to Fourteen below.

Section Six: Capacitor / battery combined power reservoir

[048] Another issue is that a good thin-film capacitor can last from 10 to 15 years while still maintaining more than 80% of its original capacitance, while a good battery can last less than 5 years and have approximately 70% of its capacity. charge after that time. Therefore, a careful design balance is suggested to optimize economic costs. In addition, the amount of energy in the reservoir must be large enough to stabilize the operation at all times. Project simulations show that, with current prices for thin-film batteries and capacitors, a typical 20-year ideal energy reservoir design for a 1 MW PV station is a project with 0.1 to 0.1 thin film capacitors. 1 Faraday combined with a battery life of approximately 50 amps per hour with an adequate operating voltage.

Section Seven: Prevent mutual annihilation of power in PV chains

[049] As described above, the decoupling technique applied in Figure 1B and Figure 1C allows the chains of solar panels to charge the energy reservoir; but it prevents the power from flowing back from the reservoir to the solar PV chains. By applying the decoupling diode set correctly, this technique not only prevents energy from escaping from the reservoir through the PV solar panel chains, but it can also prevent a phenomenon discovered by the inventors. This phenomenon is referred to in this document as the “phenomenon of mutual annihilation of power between PV chains”, the “phenomenon of mutual annihilation of power” or the “phenomenon of annihilation of power”,

[050] This phenomenon occurs when PV chains connected in parallel collect the power produced. This phenomenon is especially pronounced when PV chains connected in parallel have very different | -V characteristics, photoelectric conversion efficiencies and / or maximum power production voltages.

[051] For example, when less than all solar panels in less than all chains have shadow projections, chains that are within the shadow will have less efficiency for photoelectric conversion than those that are outside the shadow. In other words, these solar chains would have very different | -V characteristics even at the same time of the day, due to different projections of shadows. When these solar chains are connecting in parallel, the high efficiency chains can discharge part of their electrical power produced to the less efficient solar chains to interrupt the production of power in the PV solar chains. The inventors confirmed this phenomenon experimentally. Experiments also show that this phenomenon can be prevented when solar PV chains are properly decoupled.

[052] In addition, the phenomenon of power annihilation can also occur when PV chains connected in parallel have very different maximum power production voltages. For example, suppose there are two solar panel chains connected in parallel - one with 15 chain solar panels and the other with 19 chain solar panels. The power generated in the 19-panel chain will definitely flow through the 15-panel chain and the phenomenon of power annihilation will occur. Experiments show that the power received from the two chains connected in parallel above can reduce to less than half that produced by the chain with 19 panels in isolation. When properly decoupled, the power received from the two chains connected in parallel above can recover about 1.53 times what is produced by the chain with 19 panels in isolation. The experiment described above shows that (a) the phenomenon of mutual annihilation of power does not exist; and (b) appropriate decoupling techniques can prevent the phenomenon.

[053] In another experiment, a PV plant was organized to have two power production units; each unit consists of 85 solar panels of the same manufacturer and model. Each of the two power product units was configured with five (5) PV chains connected in parallel to collect the produced DC energy. Two PV chains were configured with 15 panels connected in series, two chains with 17 panels connected in series and another chain with 21 panels connected in series. When these maximum power production voltages of the chains are measured separately at noon with clear skies, the maximum power production voltages ranged from 420 volts as the lowest to 610 volts at the highest. Thus, these PV solar chains connected in parallel have very different maximum power production voltages under the same clear sky.

[054] Each of the power production units converts the collected DC power through a different DC / AC converter to AC power. To measure energy and power produced in each production unit, a kilowatt-hour meter and a watt meter were connected to the AC output of each of the production unit's DC / AC converters. These units were then connected to a transformer to supply AC power to a network. With 72 identical readings from the two power meters over a 36-day period, and with identical readings from the two kilowatt-hour meters at the end of the 36-day period, it is confirmed that all elements in these two power production units (including the two sets of meters) were substantially identical.

[055] A power production unit was then modified to be configured with 4 chains of 21 panels (and 1 panel not in use); while the other power production unit remained unchanged in the 5 chains described above. The measured power output of the modified power output unit was typically greater than 4.1 times that of the other power output unit at noon and clear skies. Then, sixty (60) days of accumulated energy provided were measured, which was derived from the readings of the two kilowatt-hour meters. The modified power production unit supplied power to the grid 3.38 times that of the unmodified power production unit. The above experiments clearly and definitively demonstrated that the phenomenon of mutual power annihilation does exist in PV chains connected in parallel; especially with chains having very different | -V characteristics or very different maximum power voltages.

[056] To conclude, an appropriate decoupling technique according to the principle described in this document can prevent energy leakage from the energy reservoir through solar chains; and it can also avoid the phenomenon of mutual power annihilation discovered between PV chains.

Section Eight: Experiments that prove surplus energy

[057] Before describing the MEUPT optimizer designs, this section describes experiments to definitively prove the existence of surplus energy in such PV power plants; which is provided for by the referenced patent publications, US2016 / 0036232 and US2017 / 0149250 A1. To reiterate, said patent publications define surplus energy as the electrical energy produced, but not extracted and / or used before being transformed into heat. Specifically, in a PV power plant, "surplus energy" includes remaining electrical energy that exists after the produced DC energy is extracted and converted into AC power by three-phase DC / AC converters. A MEUPT optimizer can be designed to capture / use that remaining electrical energy, the surplus energy. The following describes the experimental configurations and step-by-step experiments.

[058] Figure 2A shows the initial configuration of a PV 2000A power plant comprising 2 AC power production units 2100A and 2200A. Each of the AC 2100A and 2200A power production units practices blind MPPT conformation; and provides three-phase AC power to the 2600A mains. The AC 2100A power production unit consists of a 2110A DC power generator and a three-phase 2130A DC / AC converter (15 kW). The 2200A AC power production unit consists of a 2220A DC power generator and a three-phase 2230A DC / AC converter (15 kW). The 2110A power generator uses 2 PV chains connected in parallel 2111A and 2112A to generate DC electricity. The 2220A power generator uses two other solar chains connected in parallel 2221A and 2222A to generate DC electricity. Each of the 4 PV chains consists of 25 solar panels connected in series; each panel capable of producing 250W of power at noon and with clear skies.

[059] The DC power generator 2110A supplies DC power to the three-phase DC / AC converter 2130A; and the 2220A DC power generator supplies DC power to the 2230A three-phase DC / AC converter. These two converters 2130A and 2230A then convert the supplied DC power into three-phase AC power. In the experiment, the AC output power of the 2100A and 2200A power production units was measured by two three-phase AC watts meters (in kW) 2351A and 2352A, respectively. The AC power production (in kW "* hour) of these two power production units 2100A and 2200A was also measured by two 2361A and 2362A kW-hour meters, respectively. The three-phase AC power produced was then supplied to the 2600A network through transformer 2500A The PV power plant was operated, and the energy production of the two AC power production units 2100A and 2200A was measured for 7 days.

[060] The readings on the two kW-hour meters showed equal values every day during that time. This provides high confidence that all elements of these two 2100A and 2200A power production units (including the two sets of measuring instruments) are substantially identical. After this step, one of the two AC power production units 2200A was left unchanged, while the other AC power production unit 2100A was modified with a different configuration 2100B as shown on the left side of Figure 2B.

[061] The 2200B power production unit in Figure 2B is the unmodified 2200A power production unit in Figure 2B. Yet, the elements

2351B, 2361B, 2352B, 2362B, 2500B, 2600B of Figure 2B are the same as elements 2351A, 2361A, 2352A, 2362A, 2500A, 2600A, respectively, of Figure 2A. In addition, although the configuration of the 2100B power production unit is different in Figure 2B from the 2100A power production unit in Figure 2A, some of the elements of the 2100B power production unit in Figure 2B are the same as those that are included inside the 2100A power production unit of Figure 2A. For example, the PV chains 2111B and 2112B of Figure 2 are the same as the PV chains 2111A and 2112A, respectively, of Figure 2A. Likewise, the DC / AC converter 2130B in Figure 2B is the same as the DC / AC converter 2130A in Figure 2A.

[062] The following six (6) steps describe how the 2100A power production unit was modified in the 2100B configuration, and is described with respect to the left side in Figure 2B. Step 1 was to add a set of decoupling diodes 2311B between solar chains 2111B and 2112B and the three-phase DC / AC converter 2130B, which is practicing the blind MPPT conformation. Step 2 was to add a 2410B power reservoir to the configuration. Step 3 was to connect the power reservoir 2410B to the DC terminals of the DC / AC converter 2130B through another set of decoupling diodes 2312B and through a SW! 1 switch. Step 4 was to add another 2130S three-phase DC / AC converter (20 kW) in the configuration, whose converter 21308 was operated according to the direction of a MEUPT controller designed 2420B. Step 5 was to connect the DC / AC converter 21308 to the 2410B power reservoir through another set of decoupling diodes 2313B and via a SW2 switch. Step 6 was to connect the output terminals of the 21308 converter to the 2351B and 2361B power and energy measuring instrument set via a SW3 switch. Note that said "decoupling diode set" can be those diodes that are called "blocking diodes" in the art. Also note that switches SW1,

SW? 2 and SW3 are added as shown in Figure 1B, such that the relevant devices can be introduced to (or removed from) the experiments at an appropriate time in the projected experimental execution steps described below.

[063] The first night after the above modification is made; SW1 was turned on while switches SW2 and SW3 were turned off. The 2130B and 2230B converters started running early the next morning. The power meters 2351B and 2352B measuring the two outputs of the power production units 2100B and 2200B presented the same reading. The 2410B reservoir also started charging as indicated by measuring the high terminal voltage of the 2410B reservoir. The system was operated as described throughout the first day. The measured energy provided by the two power production units 2100B and 2200B were the same; as shown in the 2361B and 2362B kW-hour meter readings. This experimental step demonstrated that the added decoupling diode sets 2311B and reservoir 2410B did not alter the power and energy output of the 2100B power production unit.

[064] Switches SW1, SW2 and SW3 were activated the night after the first day of operation (second night). The 2130B and 2230B converters started running early in the morning (second day), while the 2130S converter started running at a lower power conversion level about 15 minutes after the 2130B and 2230B converters started. Afterwards, the 2130 converter increased its conversion power level every 2 minutes; which is consistent with the controller design and the increase in the energy level of the reservoir. The 2351B power meter reading (for the 2100B unit) reached about twice the 2352B power meter reading (for the 2200B unit) throughout the day - until almost sunset. The energy supplied by the two power production units 2100B and 2200B at the end of the second day was derived from the readings from the two kW-hour meters. The result showed that the energy supplied by the 2100B modified power production unit was more than double the energy supplied by the 2200B unmodified power production unit. For the next six consecutive days, switches SW1, SW2 and SW3 remained on, and the power supplied by the 2100B modified power production unit was consistently more than double the 2200B power production unit per day.

[065] The following night, switches SW2 and SW3 were turned off. The metered power supplied by the 2100B and 2200B power production units returned to the same level for the next five consecutive days during which switches SW2 and SW3 remained off. The following night, switches SW2 and SW3 were turned on again. The measured power output of the 2100B power production unit has again become more than double that of the 2200B power production unit per day for the next five consecutive days with switches SW2 and SW3 remaining on.

[066] As described above, the step-by-step execution of these experiments definitely proves the existence of said surplus energy in the PV power plant as the referenced patent publications (US2016 / 0036232 and US2017 / 0149250 A1) predicted. Specifically in the PV power plant when the DC power produced is extracted by a three-phase DC / AC converter, the remaining energy still exists. The MEUPT optimizer can capture and use this surplus energy to increase the electricity supplied to the grid.

Section Nine: Projected MEUPT Optimizer Settings

[067] The 2100B modified power generation unit (as described above and shown in Figure 2B) can serve as an example of a PV power generation unit incorporating a MEUPT optimizer. In this case, the MEUPT optimizer comprises three decoupling diode sets 2311B, 2312B and 2313B; a 2140B reservoir, and a MEUPT 2320B controller. Note that the decoupling diode assembly is referred to as the “decoupling device” hereinafter.

[068] The connections for the MEUPT optimizer modules are shown in Figure 2B and described above. Note that the surplus energy is passively extracted by the 2410B energy reservoir in this mode. Another power extractor is included as a module in the 21308 three-phase DC / AC inverter, which extracts the excess energy that is stored in the 2410B reservoir. The AC power conversion level of the 21308 converter is regulated by the MEUPT 2320B controller, such that the power loads in the 2410B power tank are approximately balanced with the power discharged from the 2410B power tank. Therefore, the “net” power charged to the reservoir within a period can be as small as desired. Smaller net power loads have the benefit of allowing a smaller 2410B energy reservoir, at the expense of tighter control by the MEUPT 2320B controller.

[069] Another modality is shown in Figure 3. This modality illustrates a configuration of the PV 3000 power plant incorporating a MEUPT optimizer that comprises only an AC 3100 power production unit that uses 500 kW 3110 solar panels to convert solar power into power DC electrical. In other words, the AC 3100 power generation unit consists of a 3110 DC power generator and a 3130 three-phase DC / AC converter (500 kW) 3130. The 3110 power generator uses 80 solar chains connected in parallel to generate DC electricity. Each of the 80 solar chains consists of 25 solar panels connected in series; each panel is declared to have a 250W DC power production capacity at noon and with clear skies. Note that this DC 3110 generator is referred to as a 500 kW electrical power generator (80 * 25 * 250 W = 500 kW); and this PV power plant is referred to as a 500 kW PV power plant.

[070] As shown in Figure 3, the 3110 power generator supplies DC power to a three-phase 3130 DC / AC converter (with 500 kW declared) through a 3311 decoupling device. The 3110 generator also provides DC power to the power reservoir 3410 via decoupling device 3312, and serves as a DC power source that charges the 3410 energy reservoir. Therefore, excess energy is passively extracted by the 3410 reservoir. The 3410 reservoir then supplies (or discharges) DC power. to another 3130S three-phase DC / AC converter (with 500 kW declared) via the 3313 decoupling device. The 3130 converter operates as an MPPT optimizer, while the 3130S converter operates as a MEUPT controller. The 3130 and 31308 converters convert the DC power supplied separately into three-phase AC power and deliver it to the 3600 mains through the same 3500 transformer.

[071] Note that the DC / AC converters used in the descriptions above can be categorized into two types; that is, one type that receives its DC power directly from the solar PV chains, and another type that receives its DC power from the energy reservoir. When the distinction of converter type is necessary in the disclosure and in the detailed description below, what receives the DC power from PV solar chains is also referred to as the “DC / AC converter PS”; while the other that receives the DC power from the energy reservoir is also referred to as the “DC / AC converter ER” in this document. When the distinction is necessary in the cases that use three-phase DC / AC converters in this disclosure, the converters will also be categorized and referred to in this document as “three-phase DC / AC converter PS” and “three-phase DC / AC converter ER”, respectively.

[072] To reiterate at a broader level; as shown in the configuration shown in Figure 4, this MEUPT optimizer provides an optimization service to a PV power plant of x MW that adequately disposed solar panel chains with a power generation capacity rating of x MW. The produced DC power is extracted by a "three-phase PS / DC converter PS" of y MW declared by the manufacturer 4130 through a 4311 decoupling device. The remaining power is charged to a 4410 energy reservoir through another 4312 decoupling device; thus, extracting and storing the surplus energy.The stored surplus energy is then converted by another “MW three-phase DC / AC converter ER” declared by the manufacturer 41308 through another decoupling device. One of the 4130 converters is regulated by an MPPT optimizer while the other 41308 converter is regulated by a MEUPT controller. Both converters convert an adequate amount of DC power into three-phase AC power; and supply three-phase AC power to the 4600 mains through the same 4500 transformer. Note that x = y = z = 0.5 in this configuration.

[073] Figure 5 presented another way of incorporating a MEUPT optimizer in a large PV power plant. The power plant is equipped with 0.5 MW classified 5110 solar panel chains and two 500 kW three-phase DC / AC converters declared 5130 and 51308. This modality illustrates another configuration for the MEUPT optimizer. One can think of the PV 5000 power plant comprising an AC power production unit (hereinafter also referred to as “AC power production unit 5100”). The 5100 AC power production unit consists of a 5110 DC power generator that is comprised of classified 500 kW solar panels, and two three-phase DC / AC converters (each declared as 500 kW) 5130 and 51308. The power generator 5110 uses 80 solar chains connected in parallel that generate DC electricity. Each of the 80 solar chains consists of 25 solar panels connected in series; each solar panel classified to have a power production capacity of 250W. The 5410 power reservoir receives the DC electrical power from the 5110 generator via a 5311 decoupling device. The two 5130 and 51308 three-phase DC / AC converters receive DC power from the 5410 reservoir via two separate decoupling devices including the 5312 decoupling device for the 5130 converter, and the 5313 decoupling device for the 51308 converter. 5130 and 51308 converters are regulated by the MEUPT controller to extract the appropriate amount of power from the 5410 reservoir, and convert the DC power into three-phase AC power to supply the grid 5600 through the transformer

5500.

[074] To elaborate more broadly on the configuration shown in Figure 5: the MEUPT optimizer provides optimization service to a PV power plant of x MW. This PV power plant has an AC power production unit with solar panel chains having a total rated DC power generation capacity of x MW. The DC generator charges a reservoir of energy through a decoupling device. The power reservoir supplies DC electricity to two three-phase DC / AC converters through two separate sets of decoupling devices. The total conversion capacity declared by the manufacturer of the two "ER three-phase DC / AC converters" is z1 +22 = z MW. Both converters are regulated by a MEUPT controller to convert an appropriate amount of DC power to three-phase AC power. produced by the two converters is supplied to an electrical network through the same transformer. The configuration described above is redesigned and shown in Figure

6. Note that x = 0.5, y = O, z = 1 in this configuration.

[075] This description will now compare the two configurations shown in Figures 4 and 6. In the configuration shown in Figure 4, the DC generator supplies DC power to a “three-phase DC / AC converter PS” with capacity declared by the manufacturer of y MW; and charges the remaining power to an energy reservoir. In Figure 4, the power reservoir supplies DC power to an “ER three-phase DC / AC converter” with capacity declared by the manufacturer of z MW. Without any “PS three-phase DC / AC converter” in the configuration shown in Figure 6 (that is, y = 0), all the generated DC power is charged to a power reservoir via an uncoupling device, and the power reservoir supplies DC electricity to two “three-phase DC / AC converters ER” via two separate sets of Therefore, x = y = z = 0.5 in the configuration of Figure 3, while x = 0.5, y = 0, z = 1 in the configuration of Figure 6. In an additional embodiment of Figure 6, there is no energy reservoir 6410. Instead, the 6110 solar chains provide DC power to the 6130 converters through a 6311 decoupling device.

[076] Now, the only remaining design problem for the MEUPT optimizer is to identify the ideal power matching relationship between the parameters that represent the rated capacity of solar chains and converters. Specifically, the task is to identify the relationship between the value of x, y and z in the ideal situation. As a reminder, the sum value y + z is not greater than the value x in a conventional PV power plant as described in Section Two.

[077] Also note that the x value is assigned to the MW value of the production capacity of classified DC power of the PV chains; the y-value is assigned to the total MW value of the capacity declared by the manufacturer of the "three-phase DC / AC converter PS" which converts the DC energy supplied by the PV chains; while the z value is assigned to the total value of MW of capacity declared by the manufacturer of the "ER three-phase DC / AC converter" which converts the DC energy supplied by the energy reservoir.

[078] For example, in Figure 6, x is equal to 0.5, the total PV capacity declared by that of 0.5 MW; y is equal to Which means that no “three-phase DC / AC converter PS” is installed; z is equal to 1, which means that the capacity declared by the total manufacturer of 1 MW of the two “three-phase DC / AC converters ER” is incorporated to receive DC power from the energy reservoir and convert the DC energy into three-phase AC power. Note that the value of y + z is not less than 2 times the value of x in the two configurations described above. The term "capacity" is also referred to as the "power rating" of the device; and is henceforth interchangeable, unless otherwise indicated.

Section Ten: The ideal power matching ratio.

[079] Due to different disciplines (industries), the definition of the power rating for solar panels is different from that of DC / AC converters. The power rating of solar panels is defined as the maximum DC power that a solar panel can produce at noon with clear skies. The solar panel manufacturing industry uses a predetermined type of lighting lamp (referred to in this document as a “standard lamp”) to simulate clear skies; and midday is simulated by a flow of illuminating light perpendicularly across the penal solar surface. Therefore, the manufacturer stated that the power production capacity can be very close to the actual capacity of the DC generator. The experiments carried out by the inventors also confirm the above statement. The total capacity for generating DC power from PV solar chains is therefore considered credible; and the title “capacity declared by the manufacturer” is omitted in this document when describing the power rating of the solar chains. On the other hand, the DC / AC converter manufacturing industry defines the power rating of DC / AC converters according to the electrical industry convention, referred to as the “electrical network convention” in this document. The convention and definition of the capacity of the DC / AC converter are elaborated below.

[080] The AC power industry applies a convention (referred to as the power grid convention) to ensure that the built three-phase AC power grid can meet the declared power delivery capacity. The three-phase AC mains consists of 3 or 4 power lines that can provide variable sinusoidal functions of voltage and current in each pair of power lines as a phase. The mains convention defines the voltage declared in the specification as the maximum "standard" voltage for the power lines to withstand (referred to as the "line voltage"). Likewise, the maximum specified current stated in the specification is the maximum current for the power lines to carry (referred to as the “maximum phase current”). When a device is manufactured to conform to the mains convention, the voltage stated in the device specification is the maximum voltage that all related components must withstand. Likewise, the maximum current stated in the specification is the maximum current carrying capacity for all related components of a phase, connecting to a pair of power lines. The time-varying functions of the voltage and current of the device must also conform to the sinusoidal function of the phase each in the AC mains.

[081] To reiterate, the specified voltage of a three-phase DC / AC converter is defined as the line voltage of the three-phase power; the maximum current specified is defined as the maximum current carrying capacity of the power line pair for each phase; and the maximum power specified is defined as the sum total of the maximum power capacity that the three phases can support. In other words, when adapting to the power grid convention, the power lines for each phase and the connected power devices must be able to transmit one third (1/38) of the specified maximum power, to state otherwise, the “Power rating declared by the manufacturer” of the three-phase DC / AC converter is 3 * U * |, where U is the phase voltage and | is the phase current. Each pair of power lines is capable of providing U * | power, or 1/3 of the “power rating declared by the manufacturer”; and each module connected to the power line pair is also required to transport or deliver 1/3 of the specified specified power rating, when adapting to the mains convention.

[082] For example, consider a three-phase DC / AC converter specifying “AC voltage = 315 VAC; maximum current = 916 amps; and the maximum power output = 500 kW "as an example. The specification" AC voltage = 315 VAC "should be read as:" the output line voltage of this converter is 315 volts ". Or, when the three-phase is balanced, the phase U voltage of each phase is U = 315 / 1.732 = 181.9 volts (where 1.732 is the square root of 3 which is the ratio of the line voltage to the line voltage). phase). The specified “maximum current = 916 amps” should be read as that the power lines and all components in each phase are indicated to guarantee the current load capacity of | = 916 amps. The "maximum power output = 500 kW" specified must be understood as the maximum capacity for conversion and power delivery of all components of each DC / AC conversion phase = U * | = 181.9 * 916 = 500/3 KW; and the maximum total conversion capacity and power delivery of the modules listed in conversion phase 3 is the sum of each phase, 3 * U * 1 = 3 * 181.9 * 916 = 500 kW, which is the “rating of power declared by the manufacturer ”= 3 * U * | when adapting to the power grid convention declared in the previous paragraph.

[083] The three phases in a three-phase DC / AC converter are strictly correlated to have 120º phase differences. In other words, a pair of power lines (phase) delivers variable power at the time of U * | sin? (wt); while the second phase delivers variable power at U * time | sin? (wt + 120º); and the third phase between variable power at U * time | sin? (wt - 120º). Each pair of power lines from the three phases delivers three oscillating AC power trains related to each other with strict correlation. Note that the power conversion capacity, P (t), is not equal to the “power rating declared by the manufacturer”. The power conversion capacity, P (t), is expressed as a function of time and derived according to the defined three-phase AC power restrictions.

[084] In other words, the DC / AC power conversion capacity, P (t), is derived from the sum of the variable power outputs over the time of the 3 phases; with a strictly correlated phase difference of 120º; and with power waveforms that conform to the square sinusoidal oscillations of sin?

(wt) or cos? (wt); and synchronized with the electrical network (same phase and frequency) that forces the angular frequency w to be constant.

[085] Now, we will derive the time-varying power conversion capacity, P (t), from the three-phase DC / AC converter. The power conversion capacity of a three-phase DC / AC converter as a function of time is P (t) = U * | * (sin? (wt) + sin? (twt + 120º) + sin? (wt - 120º)). As defined above, U is the phase voltage, l is the phase current, and w is the constant angular frequency of the power grid. Still, it can be shown that sin? (wwt + 120º) + sin? (wt - 120º) = cos? (wt) + 1/2. Therefore, the power conversion capacity, P (t), of a three-phase DC / AC converter as a function of time is P (t) = U * I * (sin? (Wt) + sin? (Wt + 120º) + sin? (wt - 120º)) = U * | * (sin? (wt) + cos? (wt) + 1/2) = U * I * (1 + 1/2) = 3/2 (U *] ).

[086] In other words, the sum total of these three pulsed power trains correlated in the three phases is a constant. In other words, the sum total of power delivery for these three pairs of power lines is a constant. Or the sum total of the three modules related to the three phases is a constant. However, this constant is only equal to half (1/2) of the “declared power capacity”. This is the relationship between the power conversion capacity and the defined “declared power capacity” of a three-phase DC / AC converter when in compliance with the electrical grid convention.

[087] Remember that, as previously described, the “power rating declared by the manufacturer” or the “power capacity declared by the manufacturer” of a three-phase DC / AC converter is 3 * U * |, when in compliance with the power grid convention. Comparing with the power conversion capacity derived above, P (t) = 3/2 (U * |); it is clear that the DC / AC power conversion capacity derived from a three-phase DC / AC converter is only half of the “power capacity declared by the manufacturer”.

[088] As an example, consider again the three-phase DC / AC converter described above; which specifies “AC voltage = 315 VAC; maximum phase current = 916 amps; and the maximum power output = 500 kW ". In reality, the DC / AC power conversion capacity of this three-phase DC / AC converter is only 250 kW. To derive the above conclusion, we first confirm that the declared maximum power, 500 kW, is actually equal to 3 * U * |, where U is the phase voltage derived from the specified line voltage, and | is the maximum declared current; the power conversion capacity of this converter is equal to 3/2 * U * | = 250 kW.

[089] The ideal power correspondence ratio for parameters x, y and z (as defined) is that the value of (y + z) should not be less than 2x. Where the related PV power plant is made up of x MW MW solar PV chains; with the three-phase "DC / AC converters PS" having total "power capacity declared by the manufacturer" of y MW; and with “ER three-phase DC / AC converters" having total “manufacturer declared power capacity” of z MW. “PS three-phase DC / AC converters” and “ER three-phase DC / AC converters” can be operated by one or more MPPT controllers, or by one or more MEUPT controllers To practice MEUPT optimization, it is preferable to operate all DC / AC converters per MEUPT controller (s).

Section Eleven: Abstracts

[090] Figure 7 illustrates in an abstract form the configuration of a PV 7000 solar power plant. The power plant comprises solar panels of x MW in total arranged in 7100 solar chains. The DC power generated in the 7100 solar chains provides DC power input. to a group of three-phase DC / AC converters 7301 via a decoupling device 7201; and loads excess power into a 7400 reservoir via a 7202 decoupling device. The 7400 energy reservoir provides DC power input to a group of three-phase DC / AC converters 7302 via an uncoupling device

7203. Both 7301 and 7302 three-phase DC / AC converters provide three-phase AC power converted to a 7600 mains through a 7500 transformer. The total “capacity declared by the manufacturer” of the 7301 converters is yY MW. The total “capacity declared by the manufacturer” of the 7302 converters is z MW. The sum value (y + z) is not less than 2x. Remember that when using a similar configuration to describe a conventional PV power plant as described in Section Two, the value of (y + z) is not greater than the value of x. Therefore, when a project with a value of (y + z) is greater than x or even better 1.1 times x; this means that part of the surplus energy can be captured to increase the electricity supplied to the grid.

[091] Converters 7301 and 7302 can all be operated by the MEUPT controller (s) described above. In some modalities, some, one or even none of the converters are operated by a MEUPT controller. In addition, in some embodiments, one or some of the decoupling devices 7201, 7202 and 7203 can be omitted in the configuration. The PV 7100 solar chains provide DC power input to the 7301 converters. Therefore, they are referred to as the “PS converters” in this document. The 7400 power reservoir provides DC power input to the 7302 converters. Therefore, they are referred to as the “ER converters” in this document. The terms "total power rating declared by the manufacturer" and "total power capacity declared by the manufacturer" must be abbreviated as the "declared power" in this document.

[092] To reiterate the description of the configuration shown in Figure 7: a PV 7000 power plant comprises x MW 7100 solar chains as a DC power generator. The DC 7100 power generator provides input to the 7301 “PS converters” with “declared power” of y MW, through the 7201 decoupling device; and loads the remaining power to the 7400 reservoir through another 7202 decoupling device. The 7400 reservoir provides input to the “ER converters” 7302 with “declared power” of z MW via the 7203 decoupling device. All three-phase DC / AC converters 7301 and 7302 provide the three-phase AC power converted to the 7600 mains through a transformer

7500. In some embodiments, the value of (y + z) is not less than the value of 2x. However, when the value of (y + z) is greater than the value of x, the project may receive a partial benefit to increase the sale of electricity to the grid.

[093] A MEUPT optimizer according to the principles described in this document can serve a small PV power plant or a large PV power plant comprising one or more AC power production units. In addition, with the properly designed decoupling device, energy leakage from the energy reservoir through the solar PV chains can be prevented. In addition, with the properly designed decoupling device, the phenomenon of “mutual power annihilation” discovered can be avoided. Furthermore, the energy reservoir can be used to receive only the surplus energy after the energy extraction from the “PS converter” or to receive all the DC energy produced before any extraction. Finally, the MEUPT optimizer can also provide service for the PV power plant equipped with a single phase DC / AC converter (s).

Section Twelve: MEUPT controller design constraints

[094] Figure 8 illustrates a MEUPT 8000 controller (also referred to as a “system controller”) that represents an example of the MEUPT 2320B controller in Figure 2B. The MEUPT 8000 controller consists of 3 executable components: an 8100 detection component, an 8200 determination component and an 8300 delivery component.

[095] The detection component 8100 measures the level of energy stored in an 8400 reservoir. An example of the reservoir is reservoir 2410B in Figure 2B, the energy reservoir 3410 in Figure 3, the energy reservoir 4410 in Figure 4, the 5410 power reservoir in Figure 5, the power reservoir

6410 of Figure 6, and the 7410 power reservoir of Figure 7.

[096] A determination component 8200 determines the appropriate power extraction level to almost balance the load supplied to and discharged from the 8400 energy reservoir.

[097] An 8300 delivery component delivers an encoded message from the appropriate power extraction level determined above to the exceeding 8500 DC / AC converter (s). The converters interpret the encoded message, and obey the coded message, such that the converter (s) can (s) continuously operate at the directed power level to almost balance the energy in the load. An example of the 8500 converters that extract from the 8400 reservoir are converters 21308 in Figure 2B, converters 31308 in Figure 3, converters 41308 in Figure 4, converters 51308 in Figure 5, converters 61308 in Figure 6, converters 7302 in Figure 3.

[098] To derive the MEUPT economic beneficial optimizer, the MEUPT controller design takes into account the following parameters and variables, (1) the capacity of the 8400 energy reservoir; (2) the up / down speed of the 8500 DC / AC converters; (3) the | -V characteristics of the solar chains; (4) the climate at the PV power plant site; and (5) the MEUPT controller's ability to work with the surplus DC / AC converter to minimize the difference between (or balance) the amount of charge supplied to the energy reservoir, and the amount of charge extracted from the energy reservoir. A direct design can only be derived by applying a custom controller to each PV power plant, taking these parameters and variables into account.

Section Thirteen: MEUPT controller designs

[099] It is impractical to customize a MEUPT controller for each PV power plant that must use a MEUPT controller. On the other hand, it is very difficult to find a direct project for the required MEUPT controller; especially when custom design controllers are not allowed. However, a terminal voltage of the energy reservoir can be seen as a measure that is influenced by each of the 5 parameters and variables. Therefore, the 5 design restrictions above can be divided into two parts when the terminal voltage of the MEUPT energy reservoir is chosen as the determining parameter.

[0100] When comparing the measured terminal voltage with a set of site-specific “standard voltage ranges”; it was clear to the inventors that the level of power extraction and conversion currently being performed by the system can be quantified since the level of power extraction is (1) very low, (2) very high or (3) exact. Therefore, the design task of the MEUPT controller can be to decouple in 1) a common industrial controller, plus 2) a bespoke site-specific “standard voltage range” table (referred to in this document as the “voltage range table ”).

[0101] Since a table of site-specific voltage ranges is built for a PV power plant; the voltage range table can work in conjunction with an industrial controller to perform the necessary functions of the MEUPT controller. The industrial controller is then composed of a detection component, a determination component and a delivery component, as also illustrated in Figure 8. However, in this case, the detection component 8100 measures the terminal voltage of the 8400 energy reservoir. The determination component 8200 compares the measured voltage with the voltage range table; and determines the amount of power extraction suitable to almost balance the energy in charging. An 8300 delivery component again delivers the encoded message of the appropriate power draw level determined above to the surplus DC / AC converter (s); such that The converter (s) can continuously operate at the directed power level to almost balance the incoming and outgoing loads from the 8400 energy reservoir.

[0102] In one embodiment, the ME00T 8000 controller 8100 detection component measures the terminal voltage of the 8400 surplus energy reservoir in real time. Even so, the determination component 8200 can still perform the comparison (of the measured voltage against the voltage interface table) for each designated time interval. This comparison can result in one of three situations: (1) If the comparison of the measured voltage and the voltage range table indicates that the power level is too low, the 8000 controller can request (via delivery component 8300) that the 8500 three-phase DC / AC converter increases the power extraction and conversion level by one for the next designated time interval; (2) If the comparison of the measured voltage and the voltage range table indicates that the power level is too high, the 8000 controller can request (via delivery component 8300) that the 8500 three-phase DC / AC converter reduce by one the power extraction and conversion level for the next designated time interval; (3) If the comparison of the measured voltage and the voltage range table indicates that the power level is accurate, the 8000 controller can request the 8500 three-phase DC / AC converter to remain at the same power draw level for the next interval of designated time, at least until the next occurrence of the comparison.

[0103] When power extraction / conversion adjustment levels of the DC / AC converter are small enough, the above project can work for all types of power reservoir capacity; for all types of up / down speed of the DC / AC converter; for all types of characteristics | -V of the solar chains; and for all climates of the PV site. Therefore, it is important that the controller can direct small adjustment steps to the three-phase DC / AC converter that draws power from the energy reservoir.

[0104] Typical conventional centralized three-phase DC / AC converters can operate in very small adjustment steps when directed. However, the equipped communication channel, referred to as the “dry connection box” in the art (and so referred to in this document), usually has only 6-bit communication channels via optical messages. To control more than 6 levels of power extraction through the dry connection box, an encoding and decoding technique is employed. This technique allows to transmit up to 26 = 64 messages to control the power extraction levels. With up to 64 levels of adjustment power extraction, the necessary net balance close to zero in the incoming and outgoing reservoir energy can be achieved technically.

Section Fourteen: PV power plant incorporating MEUPT optimizer

[0105] As shown in Figure 9, a PV 9000 power plant incorporates a MEUPT 9200 optimizer that consists of a MEUPT 9210 controller. The MEUPT 9200 controller comprises 3 executable components; that is, a 9211 detection component to measure the terminal voltage of the 9400 surplus energy reservoir; a determination component 9212 for comparing the measured voltage with the PV range voltage range table; and a delivery component 9213 for notifying the three-phase CC / AC converter 4502 to initialize, suspend or remain the same via delivery component 4213. Components 9211, 9212 and 9213 of Figure 9 are examples of components 8100, 8200 and 8300, respectively from Figure 8. The energy reservoir 9400 in Figure 9 is an example of the energy reservoir 8400 in Figure 8. The 9502 converters are examples of the 8500 converters in Figure 8.

[0106] The PV 9000 power plant also comprises solar PV chains

9100. The 9100 solar chains convert solar energy into electricity; and deliver the DC power generated to the 9400 surplus energy reservoir through the 9320 decoupling device. The three-phase DC / AC converter 9502 receives DC power input from the 9400 surplus energy reservoir through the 9330 decoupling device. The solar chains 9100 in Figure 9 are collectively a DC power source for charging the energy reservoir, and are examples of solar chains 2111A and 2111B in Figure 2B, solar chain 3110 in Figure 3, solar chain 4110 in Figure 4, solar chain 5110 in Figure 5, solar chain 6110 of Figure 6, and solar chain 7110 of Figure 7. Decoupling device 9320 of Figure 9 is an example of decoupling device 2312B of Figure 2B, decoupling device 3312 of Figure 3, decoupling device 4312 of Figure 4, decoupling device 5311 of Figure 5, decoupling device 6311 of Figure 6, and decoupling device 7202 of Figure 7. The decoupling device uncoupling 9330 of Figure 9 is an example of uncoupling device 2313B of Figure 2B, uncoupling device 3313 of Figure 3, uncoupling device 4313 of Figure 4, uncoupling device 5313 of Figure 5, uncoupling device 6313 of Figure 6, and decoupling device 7203 of Figure 7.

[0107] As indicated above, the MEUPT 9210 controller directs the 9502 three-phase DC / AC converter to extract the appropriate amount of energy from the 9400 energy reservoir to balance the incoming energy loading of the 9100 solar chains; which resulted in an almost zero energy loading or extraction in the 9400 reservoir. Thus, a small 9400 energy reservoir is suitable for the PV station. The converted AC power of the DC / AC converter is supplied to the 9700 mains through the 9600 transformer.

[0108] As used in this document, the term “executable component” is used in connection with Figures 8 and 9. The term “executable component” is the name for a structure that is well understood by one skilled in the field of computing as being a structure that can be software, hardware, firmware or a combination of them. For example, when implemented in software, one skilled in the art would understand that the structure of an executable component can include objects, routines, software methods that can be executed in the computing system, if that executable component exists in the chain of a computing system. , if the executable component exists on a computer-readable storage medium.

[0109] In this case, one skilled in the art will recognize that the structure of the executable component exists in a computer-readable medium, so that when interpreted by one or more processors in a computing system (for example, by a segment of the processor ), the computing system is made to perform a function. This structure can be computer readable directly by the processors (as is the case if the executable component were binary). Alternatively, the structure can be structured to be interpretable and / or compiled (whether in a single stage or in several stages), in order to generate a binary that is directly interpretable by the processors. This understanding of exemplary structures of an executable component is well within the understanding of one skilled in computing technique when using the term "executable component".

[0110] The term "executable component" is also well understood by a common verse as including structures that are implemented exclusively or almost exclusively in firmware or hardware, such as within a field programmable port arrangement (FPGA), an integrated circuit specific application (ASIC) or any other specialized circuit. Therefore, the term "executable component" is a term for a structure that is well understood by those skilled in computing, whether implemented in software, hardware or a combination.

[0111] The present invention can be incorporated in other specific forms without departing from its spirit or essential characteristics.

The described modalities must be considered in all aspects only illustrative and not restrictive.

The scope of the invention is therefore indicated by the appended claims and not by the previous description.

Any changes that fall within the meaning and equivalence range of the claims must be encompassed by their scope.

Claims (8)

1. Energy storage system, FEATURED by the fact that it comprises: an energy reservoir that is charged by DC energy from a DC energy source during DC energy discharge to a DC / AC converter; a system controller to regulate the dc energy discharged from the energy reservoir to the dc / ac converter to almost balance the amount of dc energy charged in the energy reservoir, the system controller comprising: a detection component configured to measure a level of energy stored in the energy reservoir; a determination component configured to use the measured level of stored energy from the energy level to assess whether an adjustment should be made; and a delivery component configured to encode the instruction to perform the adjustment on a coded message when the determination component determines that the adjustment must be made, and also configured to deliver the encoded message to the CC / AC converter. 2. Energy storage system, according to claim 1, CHARACTERIZED by the fact that the detection component measures the level of stored energy by measuring a terminal voltage of the energy reservoir. 3. Energy storage system, according to claim 2, CHARACTERIZED by the fact that the measurement of the terminal voltage of the energy reservoir occurs in real time. 4. Energy storage system, according to claim 3, CHARACTERIZED by the fact that the determination component is configured to perform the assessment of whether an adjustment should be made on a periodic basis with a designated time interval. 5. Energy storage system, according to claim 1, CHARACTERIZED by the fact that the determination component is configured to perform the assessment of whether an adjustment should be made on a periodic basis with a designated time interval. 6. Energy storage system, according to claim 1, CHARACTERIZED by the fact that the delivery component is configured to deliver the encoded message to the DC / AC converter via a dry connection box. 7. Energy storage system, according to claim 1, CHARACTERIZED by the fact that the delivery component is configured to deliver a respective coded message to each of a plurality of DC / AC converters including the DC / AC converter. 8. Energy storage system, according to claim 1, CHARACTERIZED by the fact that the delivery component is configured to deliver the respective coded message to at least one of the plurality of DC / AC converters through a dry connection box .