WO2019224583A1 - Système d'alimentation en énergie électrique - Google Patents

Système d'alimentation en énergie électrique Download PDF

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Publication number
WO2019224583A1
WO2019224583A1 PCT/IB2018/053680 IB2018053680W WO2019224583A1 WO 2019224583 A1 WO2019224583 A1 WO 2019224583A1 IB 2018053680 W IB2018053680 W IB 2018053680W WO 2019224583 A1 WO2019224583 A1 WO 2019224583A1
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Prior art keywords
electric power
electric
energy source
energy
inverter
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PCT/IB2018/053680
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English (en)
Inventor
Blanka Andrea CSIZMADIA
Zoltán CSIZMADIA
László Zsolt SÁNDOR
József Lajos ORMÓS
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Microwatt Energetikai És Szaktanácsadói Kft.
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Application filed by Microwatt Energetikai És Szaktanácsadói Kft. filed Critical Microwatt Energetikai És Szaktanácsadói Kft.
Priority to PCT/IB2018/053680 priority Critical patent/WO2019224583A1/fr
Publication of WO2019224583A1 publication Critical patent/WO2019224583A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/14—Balancing the load in a network
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources

Definitions

  • the patent application relates to an electric energy supply system with analogue process control, suitable for meeting the continuous electric power demand of residential consumers with ad-hoc electric power demand, belonging primarily to the same household, which system is connected to at least two independent electric energy sources, and one of the energy sources is a renewable direct current energy source, while the other energy source is an alternating current energy source.
  • An analogue circuit formed in the system ensures that the electric power demand of the consumer is always met by electric power coming from the energy source having the higher voltage.
  • the patent application further relates to a new commercial method for the settlement of electric power using the energy supply system based on the conversion of a non-stockable renewable energy source and the drawing of electric power.
  • Power plants meeting the electric power demand of large communities, supplying the public utility network, are usually very high-capacity power plants, they most often convert heat energy or flowing mechanical energy into electric energy, and the electric energy so produced is supplied to the electric power line system. Electric energy is difficult to store in an efficient manner.
  • DC networks are rarely constructed to meet a special electric energy demand. Where DC supply is needed, the DC electric power is usually produced on-site from the alternating current (AC) network.
  • DC networks are often designed in such a way that the AC network is converted into a DC network by rectifiers in a local power plant close to the place of consumption.
  • a typical DC network is the network transmitting electric power to tramways, it is not used for supplying household consumers. From the point of view of the place of consumption, DC networks can usually be considered as closed and technically bounded subnetworks.
  • DC grids and DC microgrids has come to the fore of interest.
  • Household and small community residential power plants are usually multi-purpose power plants, which are suitable for performing the complex task of energy production and energy distribution.
  • One of their subtasks is to produce electric power from a renewable energy source, used primarily for meeting the energy demand of the own consumers. For this the purpose, the conversion into electric power is controlled.
  • the other task of current household and small community residential power plants is to distribute the produced instantaneous electric energy.
  • the electric power from own conversion covers the own demand
  • the system supplies consumers belonging to the own household.
  • the electric power produced from a renewable energy source exceeds the instantaneous value of the own electric power demand, the remaining surplus is measured and sold, fed into the public utility electricity network. The sold surplus can be used for meeting the power demand of external consumers belonging to another household.
  • household and small community residential power plants are designed to automatically disconnect from the public utility network upon reaching a predetermined degree of deviation. Therefore, in such electric power plants, the recovery of the regular and normal operation of the household and small community residential power plant usually requires separate process control and intervention.
  • Residential electric consumers can be motor-driven devices, such as kitchen appliances, vacuum cleaners, refrigerators, washing machines; can be electric heating and warming devices, such as hot plates, microwave ovens, water heaters; can also be light sources, such as incandescent lamps, fluorescent lamps or LED lamps; as well as other devices, such as communications and entertainment devices.
  • the simultaneous use of household consumers changes the demand to be met simultaneously from instant to instant in an ad-hoc manner.
  • the production of electric power produced locally from a renewable energy source, and the connection to the public utility network for drawing-selling energy has to be controlled according to several parameters varying with time, in accordance with the instantaneous direction of the aggregate power balance.
  • Deng Duo et al. disclose a method and apparatus for adjusting wakeup time in electric power converter systems and transformer isolation, comprising a controller implemented in software, hardware and/or firmware, enabling a Maximum Power Point Tracking (MPPT) algorithm.
  • MPPT Maximum Power Point Tracking
  • the invention published under No. PL 407538 discloses a direct current grid connecting multiple components.
  • a design similar to the one disclosed is used for connecting electric distribution networks according to the HVAC system, primarily for transmitting electric power through specially designed undersea cables.
  • the current HVAC networks are installed for special electric energy distribution network purposes.
  • the published invention offers the solution used on an industrial scale for special purposes, and scaled specifically for the purpose, for smaller scale residential use in households.
  • a direct current distribution network with multiple supplies, supplied by a renewable energy source as well is supplied using a circuit controlled to a constant voltage unvarying with time and a constant power, and is also connected to a device for storing electric power.
  • a common disadvantage of the disclosed solution and the residential wind power plants and solar power plants used in practice is that in residential or small community electric power distribution networks electric energy cannot be stored, or only to a very limited extent.
  • the instantaneous surplus electric power is usually stored in batteries.
  • the direct storage of electric power in batteries is difficult to ensure, not only because the storage capacity is finite, but also for reasons of fire and property protection.
  • the storage through conversion of electric power presents other obstacles, for example the combined losses of back-and- forth conversion are not always covered by surplus energy from the renewable energy source.
  • Another difficulty in use is that the balancing of the difference in time between the storing and drawing of the electric energy produced by conversion, and the occurrence of the consumption demand is not solved in all cases either.
  • the solutions used in storage power plants for storing electric power are direct current systems with a non-linear behaviour varying along a polarization curve.
  • control is made more difficult by the time and place of switch on-off events occurring within the network compared to the instant of zero-crossing of the public utility network, and their frequency compared to the network frequency.
  • Which in other words means the distance between the storage power plant with storage capacity and the electricity consumer causing an electric energy event of switch on-off voltage change, and the phase angle corresponding to this distance in the branch supplying the given load.
  • 1/8 cycle points are 750 or 625 km away
  • the 1/16 cycle points are 375 or 312.5 km away
  • the 1/32 cycle points are 187.5 or 156.25 km away
  • the 1/64 cycle points are 93.75 or 78.125 km away from each other on a sine curve of theoretical accuracy, which also means that there is no phase difference between zero-crossing public utility network points of the same switching distance and direct current points.
  • Batteries do not follow Ohm's general law, therefore the accuracy of the measured electric parameter and the display of the meter reading also influence the electric parameter to be measured, obtained as a product. That is, the data are suitable for measurement and control of reference accuracy, but the digitally measured values and the instantaneous values calculated on their basis are not necessarily matching values in every instant, because they may depend on phase angle type data as well, therefore, at different distances there are different powers, which change according the frequency determined by the own public utility supplier, when there is neither feed-in, nor outgoing supply on the given section.
  • DC microgrids are usually designed with voltage droop or frequency droop control. Such designs can be DC microgrids with either central or distributed control.
  • Jinxin Zhao et al. disclose a Distributed control and optimization in DC microgrids on pages 18 - 26 of the November 2015 issue of Vol. 61 of Automatica.
  • Various solutions are discussed through a simplified mathematical model, covering the voltage droop and frequency droop solutions, which are examined with the simplification of real operation, in a constant current or constant impedance load - or purely resistive, or Ohm-capacitive, P - model, omitting the disturbing factors existing in reality. It is easy to see on the basis of the thorough and detailed examination of the simplified operation that even within a single household there are a lot of electric power demand related events that arise from the everyday use of the household appliances and that need to be managed by the control.
  • the invention of GB Patent No. 2519823 discloses a method and system for powering a load, wherein the power may be provided to said load by DC and AC voltage sources.
  • the specification discloses a system and method for controlling an electrical power supply to a load, comprising the use of a first, renewable electrical power source to generate a first amount of power for supply to the load, the comparison of the first amount of power to the power demand of the load, and the determination of whether to supply power to the load from a second, different electrical power source, such as the AC grid.
  • the specification discloses a digital system design and method for controlling the subprocesses of the generation of power, the comparison of the generated power and the power demand, and the determination of whether to use a second power source.
  • a disadvantage of the solution is that it uses a lot of computing resources, and leaves a lot of room for errors.
  • the first amount of power generated by the first electrical power source is maximised using MPPT, and when the comparison step indicates that there is a shortfall amount between the first amount of power generated by the first electrical power source for supply to the load and the power demand, the output of the second electrical power source is controlled so that the second amount of power is as close as possible to said shortfall amount.
  • the solution according to the invention uses computer software for MPPT, and a computer can be configured or adapted to perform the described method.
  • a device for energy conversion and electric power distribution, and a method for local load sharing can be implemented not only with a DC microgrid with battery or feed-in, but systems made for this purpose with a suitably designed analogue circuit device can also be controlled in an analogous manner. All subprocesses of such process control can be performed on-site, and thus load sharing can also be performed fully at the place of consumption through the operation of the system.
  • an electric energy system requires little human and little computing resources, and is suitable for meeting ad-hoc household consumption demand both in island operation and in power drawing operation, and can be operated without equipment suitable for the storage of electric power.
  • An object of the invention is to eliminate the disadvantages of the currently known solutions, and to develop an electric energy supply system, which system draws the energy required for its operation simultaneously on the one hand from a renewable energy source available locally, and on the other hand from an externally owned electricity network, preferably a public utility network, and which system ensures continuous and safe power supply to the electric consumers of a household or small community.
  • Another object of the invention is to ensure that the sytem is capable of operating autonomously, in an island-like manner, independently of the network of the public utility supplier, and is also capable of cooperating with it, and that, if necessary, it is capable of supplying power independently to consumers belonging to a household.
  • the system does not allow the electric power produced from a renewable source and not used by the consumers to be fed in the public utility network.
  • the system ensures that, when a sufficient amount of renewable energy is available, the power supply to the own consumers is provided through the distribution of electric power from the renewable energy source, by producing the highest instantaneous power at the highest efficiency, or if the amount of renewable energy available at a given instant is lower than the energy demand, only the necessary amount is drawn from the public utility network.
  • a method of analogue process control is preferable to a method of digital process control for the combined control of such complex processes as the subprocesses of the production of electric power from a renewable energy source and the distribution of the electric power drawn from the public utility electricity network, which control processes are required in currently available residential electric power plants in the process control of processes related to conversion into electric power, and to the distribution and drawing of electric power according to the instantaneous values, which processes are executed in the devices currently available in the market, forming an integral part of the operation of devices designed for the performance of such a complex task.
  • the invention also simplifies the commercial method for the settlement of electric power for residential power plants made exclusively for supplying consumers belonging to a household or a small community, because contrary to power plants of previous designs converting non-stockable energy sources into electric power, the operation of which also requires uninterrupted and continuous public utility supply, and the use of previously known solutions for conversion efficiency based on an at least three-dimensional function, with the value of the instantaneous conversion of the surplus convertible power of the renewable energy source exceeding the limit value, the lower limit under the instantaneous household parameters, our power drawing power plant of analogous design will not feed-in power under any circumstances. Therefore, there is no need for the technical solutions and organizational knowledge required for the previously known solutions, either for their operation or for the settlement of the electric power.
  • the idea of the invention is based on the recognition that an electric energy supply system, to be operated in a household, or according to the small community distribution model, producing electric power from a renewable energy source using a direct current converter, preferably a PV device or a small wind turbine, for supplying residential consumers found in households or small plants, preferably for supplying AC consumers that can be connected to and operated by it, and for performing load sharing between the public utility electricity network and the locally produced electric energy, preferably especially in the electric power range of ⁇ 15 kW, can be implemented by assembling analogue circuit elements and by using exclusively analogue process control.
  • a direct current converter preferably a PV device or a small wind turbine
  • the invention relates to an electric energy supply system, suitable for meeting the continuous electric power demand of residential consumers with ad-hoc electric power demand, belonging primarily to the same household.
  • the system is connected simultaneously to at least two independent electric energy sources, which supply electric energy to the system.
  • One of the energy sources is a renewable, direct current (DC) energy source
  • the other energy source is an alternating current (AC) energy source.
  • the electric power of at least one of the selected energy sources is sufficient in itself to meet the demand of the own household at all times.
  • the system contains the following elements: at least one DC/DC converter, a DC/ AC inverter, a rectifier and a consumer, wherein the elements of the system are connected to each other by electric wire.
  • the DC energy source is connected by electric wire to the direct current input point of the DC/DC converter
  • the AC energy source is connected by electric wire to the alternating current input point of the rectifier.
  • the electric wires coming from the direct current output point of the DC/DC converter and direct current output point of the rectifier are connected to each other, forming a node.
  • the electric wires of the system conducting direct current come into this node.
  • the electric wire coming from the node is connected to the direct current input point of the DC/ AC inverter.
  • the direct current output point of the DC/DC converter, the direct current output point of the rectifier, the node and the direct current input point of the DC/ AC inverter, and the electric wires connecting these points with correct polarity form a circuit designed as an analogue device within the system.
  • the circuit designed as an analogue device ensures that from the energy sources the current can flow only in the direction of the consumer.
  • the design of the system prevents the current instantaneous voltage of the node from appearing either at the converter input point, at the rectifier input point or at the alternating current output point.
  • the renewable energy source is a solar panel known in itself, or a known rotating machine producing electric power.
  • the energy source supplying the DC/DC converter is a solar panel or a PV device formed by connecting solar panels in an array, which converts the light of the Sun into electric power.
  • the solution according to the invention allows the system to contain more than one DC/DC converters, then each DC/DC converter is connected to a machine converting into electric power, which can be machines operating on the same principle, or can be machines operating on a different principle, such as the combined use of a PV device and a small wind turbine.
  • Each electric wire coming from the converter direct current output points of the DC/DC converters is connected to the node. It is easy to see that there is no need for the installation of separate data connection or data transmission.
  • the AC energy source can be any source that has properties corresponding to the network voltage signal, preferably the public utility network, or energy drawn from it, but the AC energy source can also be a generator, where appropriate.
  • Figure 1 shows the elements of the system according to the invention and their connection to each other, in a linear representation
  • Figure 2 shows the elements of the system according to the invention and their connection to concrete energy sources, in a linear representation.
  • Figure 1 shows the elements of the system: a DC/DC converter 1 , a DC/ AC inverter 2, a rectifier 3 and a consumer 4, where these are connected to each other by electric wire 7.
  • the DC/DC converter 1 has a converter input point 11 and a converter output point 12, to which electric wires 7 are connected.
  • the DC/AC inverter 2 has an inverter input point 21 and an inverter output point 22, to which electric wires 7 are connected.
  • the rectifier 3 also has a rectifier input point 31 and a rectifier output point 32, to which electric wires 7 are connected.
  • the electric wire 7 coming from the converter output point 12 and the electric wire 7 coming from the rectifier output point 32 are connected to each other, forming a node 10.
  • the electric wire 7 coming from the node 10 is connected to the DC/AC inverter 2 through the inverter input point 21 thereof.
  • the electric wire 7 coming from the inverter output point 22 of the DC/ AC inverter 2 is connected to the connection point 41 of the consumer 4.
  • the connection point 41 is the supply point of the internal circuit of the own household, which supplies electric energy to the electric household appliances connected to it.
  • the electric wire 7 coming into the converter input point 11 is connected to a DC energy source supplied with electric power from a renewable energy source, while the electric wire 7 coming into the rectifier input point 31 is connected to an AC energy source.
  • the converter output point 12, the rectifier output point 32, the node 10 and the inverter input point 21, and the electric wires 7 connected to these points form a circuit designed as an analogue device.
  • the voltages present at the converter output point 12, the rectifier output point 32, the node 10 and the inverter input point 21 form the energy sources of the circuit within the analogue device.
  • FIG. 2 shows, in addition to the elements of the system, the DC and AC energy sources as well, and their connection to the system according to the invention.
  • the DC energy source can be a simple solar panel, or a PV device 6 formed by connecting solar panels.
  • the electric wire 7 coming from the direct current output point 62 of the PV device 6 is connected to the converter input point 11.
  • the AC energy source is the public utility network 5
  • the electric wire 7 coming from the alternating current output point 52 thereof is connected to the rectifier input point 31.
  • the rectifier 3 supplies a constant effective DC1 voltage of constant direction.
  • the function of the DC/DC converter 1 is to convert the voltage of the direct current (DC) energy source to a DC2 voltage, to prevent the voltage of the node 10 from appearing at the converter input point 11, and to adjust it to the DC voltage demanded by the DC/ AC inverter 2.
  • DC direct current
  • the DC/DC converter 1 is designed is such a way that for the rated terminal voltage measurable at the output of the converter, when converting environmental potential at the rated power of the renewable energy source, a predetermined DC2 voltage appears at the converter output point 12.
  • This DC2 voltage depends on the instantaneous value of the environmental potential of the non-stockable renewable energy source, and also on the instantaneous efficiency of conversion, therefore it is a DC voltage of constant direction and variable size, the value of which is proportional to the instantaneous available electric power. Therefore, the DC/DC converter 1 is designed in such a way that during conversion under rated environmental conditions, when supplied with the rated voltage of the direct current output point 62, the DC2 voltage is higher than the DC1 voltage.
  • the rated voltage of the direct current output point 62 of the DC energy source, measured at the converter input point 11, is adjusted by the DC/DC converter 1 to the required value.
  • the DC/DC converter does not change the direct current nature of the voltage present at the converter input point 11, its function is to adjust it to the value of the DC input demanded by the DC/ AC inverter 2, to prevent the current instantaneous voltage of the node 10 from appearing at the converter input point 11 , and to ensure that the load present at the direct current output point 62 as instantaneous terminal voltage is changed as little as possible by the current value of the ad-hoc change in the set of consumers 4.
  • the DC2 voltage always depends on the instantaneous renewable energy source potential, on the instantaneous efficiency of the given energy source conversion, and also on the instantaneous impedance. This is also true when several renewable energy sources available on site are used in such a way in the DC supply branch that the different types of energy sources, by taking into account their own characteristics, are connected by electric wire 7 to an own DC/DC converter to form a separate supply branch by converter, which produces a DC2 voltage at its own output when converting the rated potential, and the so formed converter output point 12 is used as the DC supply branch.
  • the electric wire 7 coming from the converter output point 12 of the DC/DC converter 1 is connected directly to the node 10. From the point of view of the node 10, it is one of the input power components thereof.
  • the electric wire 7 coming from the rectifier output point 32 of the rectifier 3 is connected to the node 10, from the point of view of the node 10, it is another of the input power components thereof.
  • the AC/DC rectifier 3 can be any device that converts alternating current into direct current, irrespective of its input and/or output form. Its function, in addition to converting the voltage of the alternating current (AC) energy source to the DC voltage demanded by the inverter input point 21 of the DC/AC inverter 2, is to prevent the current instantaneous voltage of the node 10 from appearing in the section bounded by the alternating current output point 52 and the rectifier input point 31. It is easy to see that the solution according to the invention is not suitable for feed- in operation, however, it is capable of island operation according to the instantaneous potential of the renewable energy source.
  • the DC/ AC inverter 2 is a voltage converter that converts the direct current appearing at the inverter input point 21 into alternating voltage of a power suitable for the consumer 4, thus the consumer 4 can be connected and operated within the internal network through the inverter output point 22 of the DC/AC inverter 2.
  • the only electric wire 7 coming out from the node 10 is connected to the inverter input point 21 of the DC/ AC inverter 2.
  • the node 10 is a privileged place in the system, which is not bypassed by the power of the electric energy supplied by the elements managing the energy flow of the system according to the invention, and the voltage of which corresponds to the voltage value present at the inverter input point 21 of the DC/ AC inverter 2. This value is a decisive value of the system, the value or value range specified by the manufacturer of the component elements.
  • the voltage of the node 10 supplies the DC/AC inverter 2, by connecting directly to the inverter input point 21 thereof.
  • Kirchhoff s first law applies to the node 10 at all times, where the current supplied by he output of the DC/DC converter 1 represents the currents flowing into the node 10, and the inverter input point 21 represents the value of the current flowing out of the node 10.
  • Kirchhoff s first law, at a node the sum of the currents flowing into that node is equal to the sum of currents flowing out of that node, which law applies in real time, under all circumstances and without any active or passive intervention, automatically.
  • This design is an analogue system, which during its operation controls the extent to which the individual energy sources present on the input side prevail as a function of their instantaneous voltage conditions, and forces their input to an extent corresponding to the instantaneous load, in a shared way.
  • the electric wires 7 coming from the converter output point 12 and the rectifier output point 32 are connected directly to the node 10, that is the currents coming from the individual energy sources are currents flowing into the node 10.
  • the electric wire 7 coming from the node 10 is connected to the inverter input point 21, and thus defines the current demand of the node 10 according to the resultant impedance of the set of consumers 4, which current demand is the current flowing out of the node 10.
  • the circuit effect acts at the node 10 in such a way that the supply branches supply it with a voltage corresponding to their instantaneous power.
  • the output current demand is divided on the input side into components shared between the individual energy sources, the sum of which is equal to the output current demand.
  • the circuit of the device of the analogue system controls the proportions of the division of the current demand into components shared between the individual energy sources by supply branch in such a way, that the output current is always supplied by the energy source having the higher voltage.
  • the input currents supply the required output current together, in a shared way.
  • This consumer current demand defines the output current of the node 10, which also defines the sum of the input currents of the node 10 supplied by the converter output point 11 of the DC/DC converter 1 and the rectifier output point 32 of the rectifier 3. And the sharing of these currents between the individual energy sources is determined by their voltage conditions, there is no need for the use of switch contacts in the system.
  • the use of the system does not require measuring instruments and digital control based on organizing event-driven pre-stored processes into algorithms, when the analogue system is loaded and the load is supplied in the given way, the operating conditions are set, by selecting the DC1 and DC2 voltages the analogue control is implemented by itself. Therefore, both on-site conversion into electric power, and on-site electric load sharing can be performed by operating the system.
  • consumer 4 is used to mean a set of electric consumers operating at a given instant, using standardized alternating voltage and not exceeding the normal power demand of households.
  • the DC energy source is a machine or PV device 6 converting the rays of the Sun into electric current using the photovoltaic phenomenon.
  • Its normal operating voltage is low voltage direct current, which can take any value between zero and the so called no-load voltage as a function of the load connected to its terminals and the intensity of radiation at its surface.
  • the public utility network 5 is a basic energy source with a high power reserve, providing continuous energy supply.
  • the network supplies alternating voltage according to standardized values, it is capable of supplying the consumer directly.
  • Such a system can be made without switch contacts, preferably from analogue circuit elements.
  • a further advantage of the system is that the branch currently capable of supply can be continuously and simply selected, and the continuous back-and-forth switching of the load between the branches supplying the current power demand can be simply controlled by the DC2 and DC1 values taking into account the input of the DC/ AC inverter 2.
  • the system uses a DC energy source supplied with electric power produced from a renewable energy source to supply the consumer, if the DC energy source can meet the power demand of the consumer, then the total electric power demand of the consumer is met by the DC energy source. If the energy amount of the DC energy source is less than the energy amount demanded by the consumer, then the missing energy is supplied by the AC energy source.
  • the power of the public utility network 5 exceeds the demand of household consumers by orders of magnitude, thus the system can use it as the only energy source, if necessary.
  • the voltage of the inverter input point 21 always corresponds to the voltage demanded by the ad-hoc instantaneous impedance belonging to the own household, and thus the DC/ AC inverter 2 is capable of meeting the instantaneous electric power demand in the circuit supplied in the own household.
  • the impedance profile changes dynamically with time, and is also modified by the instantaneous status indicators of combined operation.
  • Simple summation is made more difficult by the fact that both the semiconductor elements and the batteries and capacitors, similarly to fuel cells, are ohmically non-linear circuit elements, therefore, by taking into account the inductive components, phase-correct vector summation should be performed for the correct use of the computing resources and algorithms, and load sharing should be selected by taking into account the switching distance as well, which can be avoided with the solution proposed by us.
  • the previously disclosed residential small community power plant system solutions using non- stockable renewable energy sources usually do not perform vector summation, but are designed in such a way that electric power exceeding the instantaneous electric power demand is fed in the public utility network 5 by using a separate control unit, while the electric power exceeding the own demand is measured by a separate meter.
  • These previous priority-controlled systems draw from the public utility network 5 the total instantaneous electric power demand of the own household in all cases, which demand necessarily includes the electric power demand required for the operation of the given power plant, considered to be constant, and in addition, the instantaneous demand of the consumer 4 operated in an ad-hoc manner in the household.
  • the analogue system can be controlled by selecting the value of the DC1 and DC2 voltages, and with such a design, the supply branches can be continuously selected by the stepless back-and- forth switching of the load in the system, in order to supply electric power to the consumers 4 at all times on demand exclusively within the own household.
  • the DC/DC converter 1 incorporated into the device of the system is designed in such a way that by taking into account the rated voltage measurable during the conversion of the renewable energy source, performed under rated environmental conditions, while supplying the same voltage to the converter input point 11 as that of the direct current output point 62, the DC2 voltage of the converter output point 12 is some volts higher than the DC1 voltage, which is the voltage of the normal alternating current supply of the rectifier 3, at the rectifier output point 32 thereof, for supplying the node 10 in order to supply the DC/ AC inverter 2 by taking into account the constant continuous electric power demand.
  • the usability of the solution according to our invention is characterized by the behaviour of an undersized solar panel embodiment, experienced under blackout conditions, as a stress test, to which our test system was exposed to between 15th and 18th March 2018, in an unmanaged and special period for smart grids.
  • the test system is used in an assisted mode of operation, where the installed solar panel power is less than 1 kW for meeting the daytime energy demand of a normal household.
  • the PV power of the test system under laboratory conditions is about 850 W, from which a real peak power of about 650 W can be expected, and from which 500-550 W can be drawn with the assembly according to the invention, under ideal weather conditions. Weather conditions are considered ideal when the ambient temperature is not extremely high and it is sunny.
  • test system operated under such conditions, during the period between sunrise and sunset, continuously supplied a power of 80 - 100 W, this power proved to be sufficient for operating the about 50 W pump of a gas heating system during the day, and for charging mobile phones, and allowed the use of other consumers as well, for example during the daytime hours the power of our test system was sufficient for operating a television set, while the public utility network 5 branch was under repair.
  • Such a system is simple to operate, simple to de-energise, it operates exclusively as a power drawing system in such a way that feed-in is technically impossible.
  • the device is suitable for island-operation as well, and in places where no public utility network 5 is installed, it is suitable for being supplied by an individual AC generator.
  • the system according to the invention allows the implementation of the set objectives, the energy conversions are performed in a self-controlled manner, by analogue process control.

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  • Supply And Distribution Of Alternating Current (AREA)

Abstract

L'invention porte sur un système d'alimentation en énergie électrique, approprié pour répondre à la demande de puissance électrique continue de consommateurs résidentiels avec une demande d'énergie électrique ad hoc, appartenant principalement au même foyer. Le système est connecté à au moins deux sources d'énergie indépendantes (6, 5), l'une des sources étant une source (6) d'énergie renouvelable, à courant continu (CC), et l'autre source d'énergie étant une source (5) d'énergie à courant alternatif (AC). Le système contient au moins un convertisseur CC/CC (1), un onduleur CC/CA (2), un redresseur (3) et un consommateur (4), les éléments du système étant connectés l'un à l'autre par un fil électrique (7). Le système selon l'invention est commandé de manière analogique, et son circuit analogique assure que la réunion de la demande de puissance du consommateur (4) est partagée entre les sources d'énergie, et qu'aucune puissance produite par la source d'énergie en courant continu et non utilisée par le consommateur (4) puisse être fournie dans la source d'énergie en courant alternatif.
PCT/IB2018/053680 2018-05-24 2018-05-24 Système d'alimentation en énergie électrique WO2019224583A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111579897A (zh) * 2020-04-15 2020-08-25 深圳供电局有限公司 一种用于全直流楼宇配用电系统性能评价的实验平台
CN113612380A (zh) * 2021-08-27 2021-11-05 国网江苏省电力有限公司电力科学研究院 一种综合能源站换流器的启停方法及装置
CN115459334A (zh) * 2022-10-20 2022-12-09 清华大学 农村光伏柔性直流配电网系统及方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7629708B1 (en) * 2007-10-19 2009-12-08 Sprint Communications Company L.P. Redundant power system having a photovoltaic array
US20140260410A1 (en) * 2013-03-14 2014-09-18 Regal Beloit America, Inc. Methods and systems for controlling power to an electric motor
US20140285010A1 (en) * 2011-05-24 2014-09-25 D. Kevin CAMERON System and method for integrating and managing demand/response between alternative energy sources, grid power, and loads

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7629708B1 (en) * 2007-10-19 2009-12-08 Sprint Communications Company L.P. Redundant power system having a photovoltaic array
US20140285010A1 (en) * 2011-05-24 2014-09-25 D. Kevin CAMERON System and method for integrating and managing demand/response between alternative energy sources, grid power, and loads
US20140260410A1 (en) * 2013-03-14 2014-09-18 Regal Beloit America, Inc. Methods and systems for controlling power to an electric motor

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111579897A (zh) * 2020-04-15 2020-08-25 深圳供电局有限公司 一种用于全直流楼宇配用电系统性能评价的实验平台
CN111579897B (zh) * 2020-04-15 2022-09-02 深圳供电局有限公司 一种用于全直流楼宇配用电系统性能评价的实验平台
CN113612380A (zh) * 2021-08-27 2021-11-05 国网江苏省电力有限公司电力科学研究院 一种综合能源站换流器的启停方法及装置
CN115459334A (zh) * 2022-10-20 2022-12-09 清华大学 农村光伏柔性直流配电网系统及方法

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