RU2470439C2 - Method and device for electrical network monitoring - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: application: in the field of electrical engineering. The method for monitoring of an electric distribution network including connection of an electric network for transfer of electrical energy in multiple units N₁-N_N, besides, the connection S of the electrical network is connected to the unit N₁, and the specified units are connected in series, includes the following actions: start of a roundabout from the last unit N_N and transition along units to the connection S of the electrical network with calculation of a value representing amount of electric energy sent into each unit from the previous unit, on the basis of power consumption by a unit and losses in elements arranged between this unit and previous unit, and calculation of the value representing amount of electric energy sent from connection of the electrical network to the first unit N₁, on the basis of power consumption by the unit and losses in elements arranged between connection of the electrical network and the first unit N₁.

EFFECT: higher efficiency.

18 cl, 3 dwg

Description

FIELD OF THE INVENTION

The present invention relates to monitoring electrical networks.

State of the art

Electric networks are being built to connect end-users of electric energy with power plants and other producers of electric energy. Traditionally, such networks are intended for the distribution of electrical energy produced by a small number of large power plants. Thus, the traditional power supply system is unidirectional: electric energy is transferred from the power plant to the high voltage power system, from the power system to the high voltage network (HV network), from the HV network to the medium voltage network (MV network), from the MV network to the low voltage network voltage (LV network) and, finally, from the LV network to end consumers. Other voltage levels may also occur.

The UK electrical network can be seen as such a downstream network. In the United Kingdom, electricity producers are mainly large power plants, and only a relatively small amount of electricity is produced by low-power plants, such as wind power plants, small heat and power plants (CHP), etc. Power plants are connected to the state energy system, which ensures the distribution of electric energy to consumers throughout the country. Thus, the energy system is to some extent a great source of electrical energy, although in general it does not store energy (pumped storage power plants are a rare exception).

Since consumers pay for electric energy at fixed rates, asset and load management in the full sense of the word is justified only for a high-voltage power system, to which generators are made, with the possibility of regulation. When moving to lower voltage levels, asset and load management is reduced only to matching the systems with the load. Monitoring electrical energy consumption and losses to provide an assessment of performance in such a system is relatively simple. Table 1 shows a simple example in which the HV network through a transformer feeds the CH power line, which in turn feeds nodes 1-10. The distances (cable length) from the node to the previous node (from node 1 to the transformer) are given.

Table 1 HV network Transformer Mains power Node number one 2 3 four 5 6 7 8 9 10 Distance 1.8 2,3 2,3 3,1 1,2 3,5 2.7 2.2 1.9 2,4 Flow direction -> -> -> -> -> -> -> -> -> ->

The nodes can be end-users (that is, industrial consumers of medium voltage), other radial networks in the MV network or transformers of LV networks - in this case, the node can be an LV network similar to the presented MV network of the circuit. This SN network also represents a node in the HV network, which in turn can represent a node in the energy system to which electric energy producers are connected.

In such a system, there are no operational measurements, but there is only accumulated readings (for a month, quarter or year) from the measuring instruments of end consumers. Customers change the load at their discretion, and the balance of electric energy production is ensured by maintaining the voltage of the power system and the HV network, as well as the frequency by increasing or decreasing the load of the generators. In case of serious problems in the HV network (for example, failure of a powerful generator), the MV networks are disconnected until the balance is restored (load limitation due to power shortage).

The actual cost of delivering electric energy at the moment and to a given point or node in the system is unknown, the cost is accumulated and distributed to customers in accordance with established tariffs.

Based on these accumulated readings, statistical information and information from consumers about special electrical equipment and matching the system are collected using the "best method", that is, based on a number of standard assumptions and calculations. Direct measurements (i.e. measurements on transformers) are carried out only in case of complaints from customers, for example, voltage dips, flicker, etc.

The actual condition may be the same as in table 2, and the values given therein may differ from those obtained by estimation using the best method. To obtain these values, a thorough analysis of each element in the system is necessary.

table 2 Network power VN 1463 HV network price 10 Transformer Losses 0.0427 Network cost CH 10.45 Network power CH 1401 Node number one 2 3 four 5 6 7 8 9 10 Distance 1.8 2,3 2,3 3,1 1,2 3,5 2.7 2.2 1.9 2,4 Flow direction -> -> -> -> -> -> -> -> -> -> Power flow 1400.88 1246.62 1139.29 896.00 777.26 605.01 491.95 400.67 220.10 130.02 Line losses, total 0.0137 0.0275 0,0388 0,0482 0,0509 0,0557 0,0582 0,0595 0,0599 0,0600 Cost, including losses 10.59 10.74 10.87 10.97 11.01 11.06 11.09 11.11 11.11 11.11 Consumption 135 90 230 110 170 110 90 180 90 130

The power flow at each node is shown as "power extending from the previous node to power this and the following nodes." Thus, the power flow in the node 1 is the power transmitted from the transformer to power the nodes 1-10, the power flow in the node 2 is the power transmitted from the node 1 to power the nodes 2-10, etc. Consumption at each node is shown, which is, for example, the measured consumption of the end user. Losses are shown as “transformer losses” and “line losses” (cable) and can be calculated as losses per unit of electrical energy entering the element (transformer or power line). Knowing the losses, you can calculate the actual cost of delivering a unit of electrical energy at each node. Losses and costs are critical to assessing network performance and identifying sites whose modernization or maintenance would be most effective for improving network performance.

However, many electrical networks no longer correspond to the traditional unidirectional models described above. The production of electric energy by low-power installations, especially environmentally friendly sources of electric energy, such as wind or tidal energy, as well as thermal power plants, is increasing intensively. The presence of electrical energy producers at low voltage levels of a system is known as distributed production of electrical energy.

For example, in Denmark, unlike the United Kingdom, about 70% of electric energy is generated by low-power installations. The whole system can be described as a distributed system, since the generating capacities are distributed geographically. There are a large number of low-power CHPs, as well as wind turbines. Wind turbines produce electrical energy where there is wind, and there is no centralized control of low-power installations such as thermal power plants. Therefore, when Denmark produces more electric energy than necessary, it is forced to export electric energy, for example, using an underwater cable to Norway or stop powerful power plants. The control of the production of electric energy by a thermal power plant and wind turbines and its transmission to the energy system is very limited. Several medium-sized CHPPs and high-power wind farms can be centrally stopped in an emergency.

With a significant number of distributed producers of electrical energy, the power flow in the network changes completely. Table 3 shows how the situation described above changes when two electric energy producers are connected to the same CH network with the formation of new nodes 4 and 9. The node numbers used in table 1 and 2 are shown in brackets.

Table 3 HV network Transformer Mains power Node number one 2 3 four 5 (4) 6 (5) 7 (6) 8 (7) 9 10 (8) 11 (9) 12 (10) Distance 1.8 2,3 2,3 one 2.1 1,2 3,5 2.7 one 1,2 1.9 2,4 Flow direction ? ? ? ? ? ? ? ? ? -> -> ->

The magnitude and direction of the power flow between the transformer and the node 9 are unknown. Moreover, it is not even known whether this node of the CH network is a load or source with respect to the HV network. In a distributed network, electrical energy is transmitted and consumed throughout the network, which means that the load on the network / the “actual value” of the network’s assets varies significantly. Existing best calculation methods cannot be effectively applied for this type of distributed production of electrical energy. This creates significant problems for evaluating network performance and makes it difficult to manage network assets efficiently. If it is impossible to effectively monitor the network on any part of the network, overload may occur unexpectedly, and maintenance and capital investments in network elements and assets cannot be effectively carried out.

It is believed that this type of system is likely to become more common in the future, as more and more electrical energy is generated by environmentally friendly sources such as wind and tidal installations. Such a system also favors potentially more efficient technologies, such as low-power CHPs. For the effective operation of such a system, taking into account both energy and economic efficiency, a method of accurate monitoring of the electric network is necessary.

Disclosure of invention

In accordance with the first aspect, the present invention provides a method for monitoring an electrical distribution network comprising connecting an electrical network for transmitting electrical energy to a plurality of nodes N ₁ -N _N , wherein the electrical network connection is connected to a node N ₁ , and said nodes are connected in series, including: detour from the last node N _N and the transition through the nodes to the connection of the electric network with the calculation of a value representing the amount of electric energy transmitted to each node from the previous its node, based on power consumption by the node and losses in the elements located between this node and the previous node; and calculating a value representing the amount of electrical energy transferred from the electrical network connection to the first node N ₁ , based on the power consumption of the node and the losses in the elements located between the electrical network connection and the first node N ₁ .

It is clear that the number of nodes is not limited to a value in excess of many nodes. In the limiting case of two nodes, the end node N _N and node N _{2 are the} same.

This method allows you to analyze the electrical distribution network based on power consumption in each node and losses in the elements between the nodes and the connection of the electric network.

In a traditional downflow network, the electrical connection is always a source of electrical energy, which is then consumed at the nodes. However, in the present invention, the connection of the electrical network can both transmit electrical energy to the nodes and receive electrical energy from the nodes. Thus, the flow of electric energy can be directed from the connection of the electric network to the node, which corresponds to a positive value of the "transmitted" electric energy below, or from the node to the connection point of the electric network, which corresponds to the negative value of the "transmitted" electric energy below. The amount of electric energy transferred to each node also appears to be a positive value corresponding to the consumption of electric energy, or a negative value corresponding to the production of electric energy. The amount of electric energy transferred to the node includes the amount of electric energy used in this node, as well as the amount of electric energy transferred to the following nodes, that is, nodes located further from the connection of the electric network. Both the amount of electric energy used and the amount of transmitted electric energy can, of course, take negative values, which actually corresponds to the produced and received electric energy. The present method provides a calculation of a value representing power flows between the elements, and therefore, provides an assessment of network performance without the need for a complete measurement and analysis of each part of the network.

The present method, in particular, allows to achieve a positive result in distributed networks, but can also be used for less complex networks, and in fact can be used to analyze the performance of traditional networks, as well as networks with a small share of the distributed production of electric energy. In addition, since the present method does not depend on the analysis of the actual elements and their performance, and also does not depend on the number of nodes, it can be used to predict the results of changes in the load and production of electric energy by customers. For example, the ability of the system to operate in the event of a sudden peak in load can be assessed, or a prediction of the results of introducing a new power station or wind farm can be obtained. When adding new nodes to a network model or a real network, the method can provide monitoring of the extended network without any changes.

The amount of electric energy used in the present method can be measured in units of current, which allows direct calculation of losses, although other suitable units for measuring the amount of electric energy can be used. For example, a measurement of electric energy or power can be used, and it is advantageous, since it provides the use of the method in situations where the voltage and current are unstable, for example, when the transformer forms part of the connection between the nodes.

The power consumption at each node can be, for example, the measured final consumer consumption in the LV or MV network or the consumption of a lower voltage network, for example, an LV transformer connected to several consumers and being a node in the MV network. The nodes themselves can be either single devices or groups of devices, for example, connected to a network node. The electrical connection may be a transformer connecting the nodes to a higher voltage network. Losses can be line losses in power lines and / or transformer losses.

In a preferred embodiment, the present method includes the following steps: starting a detour from the first node N ₁ and moving from the electric network connection with an estimate of the total losses at each node relative to the electric network connection and using the total losses to calculate the cost of electric energy for each node relative to the cost of electric energy in the electrical connection.

Thus, mainly the present method can be used to assess local losses, as well as local value. This allows you to determine the actual cost of any losses and perform maintenance or capital investments in the new infrastructure exactly where it is most effective. Large losses at low cost may be less important than small losses at significantly higher cost.

The step of calculating a quantity representing the amount of electrical energy transmitted from the connection of the electrical network and nodes to the following nodes can be performed by:

(a) determining the amount of electrical energy delivered to the final node N _N , based on the power consumption of the specified node;

(b) determining the loss of elements for the connection between the node N _N and the previous node N _N-1 ;

(c) calculating the total amount of electric energy transmitted to the node N _N from the connection point of the previous node N _N-1 , based on the amount of electric energy delivered to the node N _N and losses between the nodes N _N and N _N-1 ;

(d) determining the amount of electric energy used in the previous node N _N-1 , based on the power consumption of the specified node and then calculating a value representing the amount of electric energy transferred to the node N _N-1 by summing the amount of electric energy used in the node N _N-1 , and the amount of electrical energy transmitted to the node N _N ;

(e) repeating steps (b) to (d) for node N _N-1 and previous nodes to determine a value representing the amount of electrical energy transferred to each node from the corresponding previous node, before moving to node N _1, and thus determining a value representing the amount of electrical energy transmitted from the connection points of the nodes N ₁ -N ₂ ; and

(e) calculating a quantity representing the amount of electrical energy transmitted to the node N ₁ from the connection of the electric network based on the amount of electric energy delivered to the node N ₁ and the loss of connection between the connection of the electric network and the node N ₁ .

The method may include estimating losses at each node with respect to the electrical connection by:

(g) calculating the "P / P" ratio for each node, and for the first node N1, the P / P ratio is equal to the amount of electric energy leaving the electrical network connection divided by the amount of electric energy delivered to the specified node, and for each node N _2- N _N the P / P ratio is equal to the amount of electric energy leaving the previous node, divided by the amount of electric energy delivered to this node;

(h) calculating the ratio “P _trans / P" for each node, the ratio P _trans / P equal to the product P / P for a given node and P / P for the previous node or P / P for connecting the electrical network in which this node is the first node is N ₁ , and the P / P ratio for connecting the electrical network is equal to one;

(i) determining the total loss for each node as P _trans / P minus 1.

Total losses can be used to calculate the cost of electric energy in each node by:

(k) calculating the cost in the first node N ₁ by multiplying the cost of electric energy in the connection of the electric network by the ratio P / P for the node N ₁ ; and

(k) calculating the cost in the next node N ₂ and each subsequent node by multiplying the value in the previous node by the ratio P / P for the node N ₂ and each subsequent node.

Thus, monitoring a complex electrical distribution network can be accomplished by repeating a sequence of simple steps. The method of these preferred embodiments is not limited to a plurality of nodes. Thus, in the limiting case of two nodes, the end node N _N and the node N _{2 are the} same as described above, and the node N _N-1 coincides with the node N ₁ .

The simplicity of the calculations and the small amount of information transmitted from node to node at each stage allow real-time monitoring. The impact of losses on network efficiency can be determined taking into account changing conditions over the course of days or hours, thereby eliminating the use of monthly or even quarterly accumulated values to determine load points. For example, a node with relatively small total losses can have maximum losses during a period of high cost or high demand, and these losses can have a greater impact on efficiency than a node with large total losses that appear during a period of low demand.

The specified method can be applied for each voltage level of the network to monitor the entire network. Thus, the connection of the electric network can form a node in the network of a higher voltage, consisting of other similar sources and consumers or manufacturers at a given voltage level. A node can also form an electrical network connection for a lower-level network consisting of lower-level nodes.

Loss and consumption values for each node can be stored. Such storage may be performed in a storage device located in the computing device for each node. The indicated values can be read by any suitable device and transmitted to a computer for further analysis. In another example, some kind of analysis can be performed on each node before the results are output for that node or data is transferred somewhere.

The determination of values for each node can be performed remotely. However, the determination of values is preferably performed by a computing device at each node.

In accordance with a second aspect, the present invention provides a method for monitoring an N _x node in an electrical distribution network having a plurality of nodes, comprising: estimating an amount of electric energy consumed by an N _x node and determining transmission power loss from a previous N _x-1 node; receiving from the next node N _{x + 1 the} amount of electrical energy transmitted from the node N _x to the specified node N _{x + 1} ; and calculating the amount of electric energy transmitted to the node N _x from the previous node N _x-1 based on the amount of consumed electric energy, transmission loss and the amount of electric energy transferred to the next node N _{x + 1} , and transferring this value to the previous node N _x-1 .

The method in accordance with the second aspect allows you to determine the values related to the place next to each node, only on the basis of information transmitted from adjacent nodes. Thus, knowledge of the entire network is not required. Therefore, expanding the network by including additional nodes does not pose a problem for the present invention.

Preferably, the method in accordance with the second aspect includes: calculating the P / P ratio for the node N _x based on the amount of electric energy transmitted to the node N _x from the previous node N _x-1 and the transmission loss between the node N _x and the previous node N _x-1 , transmitting the P / P value for the N _x node to the next N _{x + 1} node; receiving the P / P value for the previous node N _x-1 , calculating the ratio "P _trans / P" for the node N _x , and the ratio P _trans / P is equal to the product P / P for the node N _x and P / P for the previous node N _{x -1} , and determining the total losses relative to the connection of the electric network for the node N _x as P _trans / P minus 1. In addition, the method may include: receiving the value from the previous node N _x-1 , calculating the cost in the node N _x by multiplying the cost in the previous node N _x-1 to the ratio P / P in the node N _x and the transfer of the value for the node N _x to the next node N _{x + 1} .

Thus, local losses and costs can be calculated without knowing the entire network.

In accordance with a third aspect, the invention provides an apparatus for monitoring an N _x node in an electrical distribution network having a plurality of nodes, comprising: a data receiving device for receiving data from the next N _{x + 1} node regarding the amount of electrical energy transmitted from the N _x node to the specified node N _{x + 1} , a computing device configured to estimate the amount of electric energy consumed by the node N _x , determine the power loss during transmission from the previous node N _x-1 and calculate the number of elec tric energy transferred to the node N _x from the previous node N _x-1 , based on the amount of electric energy consumed, transmission losses and the amount of electric energy transferred to the next node N _{x + 1} , and a data transmission device for transmitting data regarding the amount of electric energy transferred to the node N _x from the previous node N _x-1 , to the previous node N _x-1 .

The device may be configured to perform the method of the preferred embodiments in accordance with the second aspect described above.

The device may be located away from the node. However, in a preferred embodiment, the device is located in a node. Since each node can have a device for monitoring this node and transmitting / receiving data from adjacent nodes, you can easily add a new node to any point on the network that has a device for its own monitoring, which can be connected between adjacent nodes that were previously connected to each other to friend.

In accordance with a fourth aspect, the present invention provides an apparatus for monitoring an electrical distribution network comprising an electrical network connection for transmitting electric energy to a plurality of nodes N ₁ -N _N , wherein the electrical network connection is connected to a node N ₁ , and said nodes are connected in series, comprising a device data processing, configured to implement the method in accordance with the first and second aspect described above.

The device can be configured to monitor multiple nodes or the entire sequence of nodes in the network. However, the device preferably comprises a monitoring device at each network node. The device described above in accordance with the third aspect can be installed in each node.

The nodes may be provided with means of measuring electrical energy to monitor the consumption of electrical energy. Some measurements at the final consumer are always necessary, but the consumption in nodes located above the final consumer can be calculated using the method described above and then transferred to the higher-level network as a value of the node consumption. When installing measuring instruments for each end consumer, the method and device described above can be used to determine losses only on the basis of the readings of these measuring instruments and basic information about the characteristics of the system. Thus, there is no need to monitor all network nodes. However, the use of a larger number of measuring instruments provides greater monitoring accuracy, since additional measuring instruments make it possible to compare the values calculated from the lower-level network with the measured values. Thus, the monitoring of consumption at each node can be carried out using a measuring tool.

Measurement tools can be built into the device in accordance with the third aspect, which will allow direct transmission of consumption data to the computing unit.

In accordance with another aspect of the invention, the invention provides a computer program comprising instructions that, when executed, enable a data processing apparatus to execute a method in accordance with the first or second aspect described above.

In accordance with another aspect, the invention provides a method for controlling an electrical distribution network comprising connecting an electrical network to transmit electrical energy to a plurality of nodes N ₁ -N _N , wherein the electrical network connection is connected to a node N ₁ , and said nodes are connected in series, including: transmission electrical energy between the mains connection and the first node N _1, and between each node and the next node, determining the consumption or production of electricity at each kt e and the amount of electrical energy transmitted between a first node and a compound of the electrical network, determining losses in energy transmission between the mains connection and the first node N ₁ and between each node and the next node, and monitoring the electricity distribution network or the nodes therein using a method described above in accordance with the first or second aspect and its preferred features.

Brief Description of the Drawings

The following are preferred embodiments of the present invention by way of example only and with reference to the accompanying drawings, in which

figure 1 is a diagram of a state electric power system;

figure 2 is a diagram of the nodes of a generalized network;

figure 3 is a graph of changes in the price of electric energy during the week.

The implementation of the invention

As an example of a distributed network, FIG. 1 shows an electric power system used in Denmark. In this example, there are five voltage levels. The largest generating capacities are provided by one or several traditional power plants, which transmit power of the order of thousands of megawatts to a 13-volt network with a voltage of 400 kV. This network is used to transmit electrical energy over long distances. Then, the voltage is reduced to 150 kV and supplied to the regional network 14. This network also has generating capacities connected to it, such as powerful wind turbines 15 located at sea.

The voltage in the network of 150 kV is then reduced to 60 kV and supplied to the district networks, which can be considered as the above-described HV networks. This network can be connected to wind turbines 16 located on land, and powerful district heat and power plants 17.

To distribute electric energy to various local sites, the voltage drops to 10 kV with the formation of networks of 20 SN. Less powerful CHPs 18 and less powerful wind power plants 21 can also power this part of the network with electrical energy. It is from this part of the network that large industrial buildings 19 are fed, and in some cases they may be able to transfer electrical energy to the network.

Local distribution networks 22 and 23 with a voltage of 400 V are supplied from each medium voltage network 20 through transformers.

Local network 22 contains several consumers 22a, 22b, etc. In local network 23, some consumers have their own generating capacity. These generating capacities include cogeneration plants 23a and 23b.

From the following description, it will become clear that in this system, electrical energy is transmitted to the distribution network at various voltage levels. If there is excess power in the network, it can be exported from level 3 with a voltage of 400 kV via international submarine cables.

In accordance with the invention, network monitoring is provided by computing devices using data at nodal points. For example, in the network 20 SN there are five nodes, including in order, starting from the transformer, which is the connection of the electric network: local network 23, wind power installation 21, industrial consumer 19, CHP 18 and local network 22. At points outside the local network 22 other nodes may be located.

Figure 2 is a diagram of a generalized network having an electrical network connection S in the form of a transformer connecting a lower voltage network 24 to a higher voltage network 25. The connection of the connection S of the electric network to the higher voltage network 25 forms a node 26 in the network 25. Three nodes are shown in the lower voltage network 24 as a sequence of nodes N _x-1 , N _x and N _{x + 1} . Each node has a node load, which consumes electrical energy from the network. The nodes are connected by transmission lines 27, 28. It is clear that before and after the shown nodes N _x-1 , N _x and N _{x + 1,} any number of nodes can be connected.

Each node has a computing unit or node computing device configured to calculate losses in an element of the distribution network (i.e., cable of a given length, transformer) between this node and the previous node (towards the point of common connection) in this network and calculate the accumulated losses and relative cost in this node based on the following information: relative characteristics, such as loss characteristics, nodal load and load of the previous node. The computing unit transmits information about the total load, including the nodal load plus the load of the following nodes to the previous node, and also transfers information about the accumulated losses and relative cost to the next node.

The imaginary network from table 3 was used for calculation as an example of a method for monitoring and operation of a nodal computing device. In this case, the "network elements" (except for the transformer) are sections of the CH network cable with the indicated lengths ("distance"). The calculation results are shown in table 4.

For clarity, it is better to start the loss calculation from the last node and move towards the transformer. Table 5 shows the calculation results for nodes 7-12 from table 3.

In table 5:

"Elem losses." (loss of elements) are the total losses in the cable of the CH network from the connection point of the previous node, calculated as the current at the rated voltage (transformer).

"Total current" is the sum of the node current and current of the following nodes, calculated at the connection point of the previous node. A negative value means that the flow is directed to the transformer / previous node.

"Nodal current" is the nodal current calculated at the connection point of the previous node. A negative value means that the node is a source of electrical energy, and not a consumer.

"R / P" is the ratio of the power extending from the connection point of the previous node to the power entering the connection point of this node. If P / P is greater than 1, then the flow is directed to the previous node.

"Rtrans / R"("R _trans / R") is the ratio of the power leaving the transformer to the power entering the connection point of this node.

"Total losses" are losses in relative units in a node relative to the transformer.

“Cost” is the relative cost / value in a node relative to the price of the transformer.

"Reference current" is the value of the reference current delivered to the node, calculated at the rated voltage (rated voltage of the transformer, in this example 10 kV) from electric power (kW). This power value can be obtained from the nodal measuring means or obtained as a result of a sequence of calculations similar to the calculations in this network and based on the readings of the measuring instruments of the final consumers.

In this example, the power factor is assumed to be 1, but other power factors, both fixed and variable, that is, due to the HV / CH transformer, can be used.

The calculations are performed as described below, with the sign ^"*" indicates the operation of multiplication.

The total value of the reference current supplied to the connection point of the bridle (etc.) is found as the sum of the "reference current" and the current for the connection point of the next node. This value is not shown in table 5.

For the connection point of node 12, the total reference value = "reference current", since node 13 is absent. Losses of elements (“loss of elements”) from the connection point (etc.) of the node 11 to the connection point of the node 12 are equal to the losses in the cable, which can be defined as the squared current * element size (resistance of a cable unit) * cable length. In this example, the value of the cable element is 0.0001 / unit, and the cable length is 2.4 units. Based on this information, the computing unit of node 12 calculates the amount of electrical energy (in this example, the number of units of current) that leaves the node 11 as follows

→ Loss of elem. = 0.0001 * 2.4 * 7.506 * 7.506 = 0.0135

→ P / P (units departing from the like of node 11 in relative units to the like of node 12) = (7.506 + 0.0135) / (7.506) = 1.0018.

→ Total current (value for the like node 12 s.r. at the reference current of the like node 11) = 7.5 * 1.0018 = 7.5191.

The value of the "total current" is then transmitted to the node 11. Therefore, the reference current arriving at the like. node 11 is equal

("Reference current" of the node 11) + ("total current" of the node 12) = 12.715,

The computing unit of node 11 then calculates the units delivered from node 10 in the same way as above.

→ Loss of elem. = 0.0001 * 1.9 * 12.715 * 12.715 = 0.0307.

→ P / P (units departing from the like of node 10 in relative units to the like of node 11) = (12.715 + 0.0307) / 12.715 = 1.0024.

→ Total current (value for the like node 11 at the reference current of the like node 10) = 12.715 * 1.0024 = 12.7459.

The value of the "total current" is then transmitted to the node 10.

Reference current coming to the like node 10.

("Reference current" of node 10) + ("total current" of node 11) = 23.138.

The computing unit of node 10 then calculates the units delivered from node 9, as above

→ Loss of elem. = 0.0001 * 1.2 * 23.138 * 23.138 = 0.0642.

→ P / P (units departing from the like of node 9 in relative units to the like of node 10) = (23.138 + 0.0642) / 23.138 = 1.0028.

→ The total current (value for the like node 9 with a reference current for the like node 10) = 23.138 * 1.0028 = 23.2025.

The value of the "total current" is then transmitted to the node 9.

Reference current coming to the like 9:

("Reference current" of node 9) + ("total current" of node 10) = - 11.439.

Here, the "reference current" is negative, which means node 9 is the source, but calculations for the like. node 8 are the same.

→ Loss of elem. = 0.0001 * 1.0 * (- 11.439) * (- 11.439) = 0.0131.

→ P / P (units departing from the like of node 8 in relative units of the like node

9) = (- 11.439 + 0.0131) / (- 11.439) = 0.9989.

→ Total current (value for the other node 8 at the reference current for the other node

9) = - 11.439 * 0.9989 = -11.4254.

The value of the "total current" is then transmitted to the node 8.

In this case, the "total current" is also negative, so the power flow from the like. node 8 in the like node 9 is negative, which means the flow of power (and loss) is directed from the like. node 9 to the like node 8.

Reference current coming to the like node 8:

("Reference current" of node 8) + ("total current" of node 9) = - 6.2292.

Here, the "reference current" is positive, since node 8 is a consumer, and the "total current" from node 9 is negative, and the power flow is directed from node 9, but the calculations are for the like. Node 7 are the same.

→ Loss of elem. = 0.0001 * 2.7 * (- 6.2292) * (- 6.2292) = 0.0105.

→ P / P (units departing from the like of node 7 in relative units in the like of node

8) = (- 6.2292 + 0.0105) / (- 6.2292) = 0.9983.

→ Total current (value for the like node 7 at the reference current for the like node

8) = - 6.2292 * 0.989 = -6.2188.

The value of the "total current" is then transmitted to the node 7.

In this case, the "total current" is also negative, and the power flow (and loss) is directed from the like. node 8 to the like node 7.

Reference current coming to the like node 7:

("Reference current" of node 7) + ("total current" of node 8) = 0.1321.

Here, the "reference current" is positive, since the node 7 is a consumer, and the "total current" from the node 8 is negative, and the power flow is directed from the node 6, but the calculations are for the like. Node 6 are the same.

→ Loss of elem. = 0.0001 * 3.5 * (0.1322) * (0.1322) = 0.000006.

→ P / P (units departing from the like of node 6 in relative units to the like of node 7) = (0.1322 + 0.000006) / (0.1322) = 1.00005.

→ Total current (value for the like node 6 at the reference current for the like node 7) = 0.1321 * 1.00005 = 0.1321.

The value of the "total current" is then transmitted to the node 6.

In this case, the "total current" has become positive, and the power flow (and loss) is directed away from the like. node 6, etc. node 8 to the like node 7.

This order of calculations is repeated by each nodal computing device, and the computing device of node 1 calculates the power flows from the VN / CH transformer. The whole sequence of calculations is continuously repeated at short intervals (for example, after 1 second).

The HV / CH transformer can itself be equipped with a computing device and thus can form a node with a computing device in the HV network.

In the same way, the node in the MV network can be an MV / LV transformer connected to the LV network with nodes and computing devices, which can also be industrial end users or generators, but in this case information about the "reference current" can be obtained from measuring means end users who form the basis of the measuring system.

After that, losses, P / P ratio and total current for each node can be determined, as well as “total losses” and, therefore, “cost” for each node. Since both the "total losses" and "cost" (or value) in the calculations refer to the CH side of the HV / CH transformer, for simplicity of description, it is better to start the calculation from the first node from the transformer (node 1) and go towards the end of the line. Table 6 shows the results for nodes 1-6, and the calculation procedure is described below.

Table 6 Node 1 Node 2 Knot 3 Knot 4 Node 5 Node 6 1.8 distance 2.3 distance 2.3 distance 1 distance 3.1 distance 1.2 distance 0.0001 Elem loss. 0.0118 Elem loss 0.0354 Elem loss. 0.0663 Elem loss. 0.0825 Elem loss. 0.0119 Elem loss -> <- <- <- -> -> 0.6287 total current -7.1656 total current -12.3736 total current -25.6880 Total current 16.3922 Total current 9.9589 Total current 7.7951 Nodal current 5.1876 Nodal current 13.2412 Nodal current -42.0380 Nodal current 6.3830 Nodal current 9.8267 Nodal current 1,0001 R / R 0,9983 R / R 0,9971 R / R 0,9974 R / R 1,0051 Р / Р 1,0012 R / R 1.0001 RTrans / R 0.9985 Rtrans / P 0.9956 RTrans / R 0.9930 RTrans / R 0.9981 RTrans / R 0.9993 RTrans / R 0.0001 Total Losses -0.0015 total losses -0.0044 total losses -0.0070 total loss -0.0019 total losses -0,0007 total loss 10,0011 Cost / kWh 9.9846 Cost / kWh 9.9561 Cost / kWh 9.9305 Cost / kWh 9.9807 Cost / kWh 9.9926 Cost / kWh 7.7942 Reference current 5.1962 Reference current 13.2791 Reference current -42.1466 Reference current 6.3509 Reference current 9.8150 Reference current 135-, kW 90-, kW 230-, kW -730-, kW 110-, kW 170-, kW

As described above, the value of "P _trans / P" represents the relative units departing from the transformer in a given like. node, and is calculated as follows

P _trans / P = (P _trans / P value from the previous node) * P / P

In the transformer "P _trans / P" = 1. Therefore, in node 1, "P / P" = "P _trans / P".

The value of the "total losses" is a relative value, as well as "P _trans / P", and here means the units lost during the delivery of one unit to this node relative to the transformer. Cost is calculated as follows

Total losses = ("P _trans / P") - 1.

As a result, losses due to the generation of electrical energy in the network can be represented by negative values. Of course, this can be corrected by using absolute values, since they are really losses, but in this case negative values are saved to clearly divide the network loads into “losing” and “winning”, that is, negative losses in the consumer node represent the “winning” node but in the manufacturer’s node they represent the “losing” node.

“Cost” represents the cost of delivering one unit (kWh) of energy from a transformer or the carrying amount of electrical energy from a producer in the network. Cost is calculated as follows

Cost = (cost of the previous node) * P / P, since P / P represents "units departing from the previous one of the node. In relative units in the like of this node".

The computing unit (vb) of node 1 receives the value of "P _trans / P" and "cost" from the previous node (in this case, the transformer).

P / P (node 1) = 1.0001.

→ P _trans / P = 1 * 1.0001 = 1.0001 (transformer value = 1).

→ Total losses = 1.0001-1 = 0.0001.

→ Cost = 10 * 1.0001 = 10.001.

In this case, only part of the electrical energy is transmitted from the transformer. Therefore, the losses are very small and the cost is almost equal to the price in the transformer.

B. b. node 2 receives from node 1 the values of "P _trans / P" (= 1.0001) and "cost" (= 10.001).

P / P (node 2) = 0.9983.

→ P _trans / P = 1.0001 * 0.9983 = 0.9985.

→ Total losses = 0.9985-1 = -0.0015.

→ Cost 10.001 * 0.9983 = 9.9846.

For node 2, all electrical energy is transmitted from the like. node 3, and the power flow is directed to the like node 1, with P / P <1, and in this case, the total loss is negative. Since node 2 is a consumer, it is therefore a “winning" node. The cost is reduced compared to the price in the transformer.

B. b. node 3 receives from node 2 the values of "P _trans / P" (= 0.9985) and "cost" (= 9.9846).

P / P (node 3) = 0.9971.

→ P _trans / P = 0.9985 * 0.9971 = 0.9956.

→ Total losses = 0.9956-1 = -0.0044.

→ Cost = 9.9846 * 0.9971 = 9.9561.

For node 3, all electrical energy is transmitted from the like. node 4, and the power flow is directed to the like node 2, with P / P <1, and in this case, the total losses are negative. Since node 3 is a consumer, it is therefore a “winning" node.

B. b. node 4 receives from node 3 the values of "P _trans / P" (= 0.9956) and "cost" (= 9.9561).

P / P (node 4) = 0.9974.

→ P _trans / P = 0.9956 * 0.9974 = 0.9930.

→ Total losses = 0.9930-1 = -0.0070.

→ Cost = 9.9561 * 0.9974 = 9.9305.

Node 4 is the manufacturer, and the power flow is directed to the like. node 3 s.r., with P / P <1 and the total losses are again negative. Since node 4 is a manufacturer for which “Cost” = “Value”, it is a “losing” node.

B. b. node 5 receives from node 4 the values of "P _trans / P" (= 0.9930) and "cost" (= 9.9305).

P / P (node 5) = 1.0051.

→ P _trans / P = 0.9930 * 1.0051 = 0.9981.

→ Total losses = 0.9981-1 = -0.0019.

→ Cost = 9.9305 * 1.0051 = 9.9807.

Node 5 is a consumer, and all electrical energy is transmitted from the like. node 4, with P / P> 1, but the total losses remain negative. Since node 5 is a consumer, it is therefore a “winning" node.

This calculation order is repeated by each nodal computing device to the last computing device in the network (node 12). The whole sequence of calculations is continuously repeated at short intervals (for example, after 1 second).

The HV / CH transformer can itself be equipped with a computing device and thus can form a node with a computing device in the HV network, from which the "cost" is obtained.

In the same way, a node in an MV network can be an MV / LV transformer connected to an LV network with nodes and computing devices, which can also be industrial end users or generators, but in this case the last computing device is built into the measuring instrument of the end consumer, which uses the calculated "cost" directly for conducting commercial reporting, as well as accounting for energy consumed and transfers the information further to the equipment of the final consumer, th with the ability to respond to the price that forms the basis of a system of means adapted to respond.

Actual cost (rather than power loss) as the basis for invoicing the customer and managing the load is very important, since electricity prices are extremely volatile. It makes no sense to invest if the losses eliminated by the investment appear only at very low prices (or even zero prices), for example, in the case of generating a large amount of electric energy by a wind turbine at night.

Figure 3 shows a graph of the price of electric energy for a typical week at the Kontek site (part of Nord Pool in Denmark). Prices range from zero to 149 € / MWh (= 14.9 cents / kWh), which is a "low" peak. The record price for this plot is more than 10 times higher.

Obviously, power losses at a price equal to zero are almost irrelevant, in this situation only the total power of the system matters. On the other hand, at a price of 14.9 cents / kWh at the level of the HV energy system, power losses obviously need to be minimized.

In the “actual cost” system described above, customers can be energy consumers, energy producers, or both. Each node may contain generating equipment with variable power and operating costs, each network may have different power / load / loss characteristics that vary over time, connections to the power system may be strong or weak, and the power generated by wind farms may be variable. Such a calculation system allows the customer’s equipment, configured to respond to the price, to optimize the power supply system up to the last element by continuously controlling the loads and input values to ensure optimal performance of the individual components and the entire network. Thus, load management turns into a continuous process.

The disadvantages of this fixed-rate system are shown in FIG. 3, in which price peaks represent a shortage of generating capacities, and drops to zero represent an excess of generating capacities. In a fixed-rate system, customers pay at the same price per unit of electricity at any time. In the example with the Kontek section, the price can be about 6 cents / kWh without taking into account the tariffs of the energy system and network, as well as taxes. Even if the customer’s equipment, configured to respond to the price, is only part of the full load, the effect on peak prices is very significant, since the price / load ratio in the extreme areas of the price can be 50: 1 or more. Consumers' reaction to higher prices (reflecting a shortage of generating capacities) may consist in decreasing the share of non-essential consumers, and producers of electric energy, if possible, can increase the production of electric energy.

In addition, if there is a computing unit in the transformer as well, the entire network powered by this transformer can belong to the HV network as one virtual power station with the ability to respond in extreme situations. For example, the peak price of 14.9 cents / kW · h in the Kontek section, shown in FIG. 3, can, taking into account transmission costs and operating costs, make up the actual price of 18 cents / kW · h on the HV side of the HV / CH transformer. In response to this price level in a network configured to respond, the TPPs in nodes 4 and 9 will work, and the consumption of electric energy by other equipment configured to respond to the price in nodes 3 and 10 can be reduced. As a result, the CH network can be a generator with respect to the HV network. Power losses are very small, but due to the high price they are nonetheless economically significant (up to 0.47 cents / kWh). Table 7 shows the results of these changes.

In another case, zero consumption can cause a price of 2 cents / kWh on the HV side. In this case, the production of electric energy by units 4 and 9 of the CHP will obviously be stopped. In the example shown in table 8, the node 4 does not produce electrical energy, but uses cheap electrical energy for heating, while the nodes 3 and 10 again consume electrical energy in normal mode. In this case, the power losses are very significant, and only 85% of the electric energy delivered by the HV network reaches the nodes, but the economic losses are less than in the previous case (up to 0.43 cents / kWh), and all consumers receive cheap electric energy .

Table 8 Power supply VN 2256
VN network price 2.00 Loss Transformer 0.0629 Network cost CH 2.13 Power network CH 2114 Node number one 2 3 four 5 6 7 8 9 10 eleven 12 Distance 1.8 2,3 2,3 one 3,1 1,2 3,5 2.7 one 1,2 1.9 2,4 Flow direction -> -> -> -> -> -> -> -> -> -> -> -> Power flow 2113.66 1934.17 1796.89 1525.95 912.73 788.29 614.03 496.60 402.81 401.88 220.77 130.23 Line losses, total / unit 0.0215 0.0471 0,0715 0,0809 0.0982 0.1042 0.1178 0.1263 0,1290 0,1321 0.1348 0.1369 Cost, including losses 2.18 2.23 2.29 2,34 2,36 2,39 2,39 2.40 2.41 2.42 2.42 2.43 Consumption 135 90 230 600 110 170 110 90 0 180 90 130

It is clear that under such conditions price fluctuations are significantly reduced. When using the proposed system in full, that is, when monitoring and managing the entire network in accordance with the method described above, the entire power supply system can be significantly changed: the balance of the system is provided mainly by end users absorbing fluctuations in power supply, for example, due to power generated in the HV power system by wind farms. Existing connections of HV transmission lines with neighboring sections in a larger power system (for example, ЕЕ _х - E.ON, DK East) unexpectedly turn out to be in demand.

As a result, load management is greatly improved thanks to the monitoring and calculations described above.

It also provides asset management benefits for power grids. Asset management requirements are very different from load management requirements. In this context, asset management involves the collection of material information to determine a sound basis for investment decisions.

Regarding this system of calculations, this means that

- operational values from load control functions must be accumulated, and

- computing devices must be configured to communicate with elements outside the “nearest neighbor”.

In a very simple embodiment, the computing device simply accumulates values for electric load, "economic load", power loss and economic loss of an element in a storage device configured to be accessed by a suitable reader, by which the operational costs of this element can be determined.

In a more complex version, the computing device collects the accumulated values by the necessary parts, that is, economic losses for different electrical loads, on the basis of which the cost / value of another element can be estimated.

In an even more complex embodiment, the computing device performs a set of parallel calculations and collecting values for the virtual element and / or virtual load, based on which the cost / value of the virtual element can be estimated.

In an even more complex embodiment, the computing device transmits a set of parallel computations, including element loss, to neighboring computing devices, and also receives, processes and transmits parallel sets of information from neighboring computing devices in the same way as in the main operational order. Based on this, the network cost / value of the virtual load and virtual element can be determined.

In an even more complex embodiment, the computing device of the VN / CH transformer transmits the above information to a computer configured to access the network operator.

In an even more complex embodiment, the computing device can, upon request or at specified intervals (for example, 1 min), transmit information packets containing the collected and accumulated values to a computer in which they can be stored with a time stamp as “nodal information” once again and saved as network information.

The value of the total transmission losses in the network (here 10 kV) can be calculated by the formula:

Losses during transmission in the network = (sum (element loss)) * √3 * 10 kV (kW) at a power factor of 1.

Of course, other power factors (measured or calculated) can be used.

Another value of the total transmission loss in the network can also be calculated by the formula:

Losses during transmission in the network * = (transformer load (SN side)) - (sum (nodal loads)). However, this requires measurements on the CH side of the transformer. On the other hand, such measurements can be used to calibrate individual computing units by calculating the "network power factor" based on the difference between "network transmission loss" and "network transmission loss *".

Then, the total economic losses in the network can be calculated by the formula:

(transmission losses in the network) * (unit price on the CH side of the transformer)

Claims (18)

1. A method for monitoring an electrical distribution network containing an electrical network connection for transmitting electric energy to a plurality of nodes N ₁ -N _N , wherein the electric network connection is connected to a node N ₁ , and said nodes are connected in series, including calculating a quantity representing an amount of electric energy, transmitted to each node from the previous node, based on the power consumption of each node and losses in the elements located between this node and the previous node, while the calculation begins with the last node N _N and then continue through the nodes towards the connection of the electric network; and calculating a value representing the amount of electrical energy transmitted from the electrical network connection to the first node N ₁ , based on the power consumption of the first node and the losses in the elements located between the electrical network connection and the first node N ₁ . 2. The method according to claim 1, characterized in that it includes an estimate of the total losses in each node relative to the connection of the electric network, wherein the evaluation starts from the first node N ₁ and then continues through the nodes in the direction from the connection of the electric network; and the use of total losses to calculate the cost of electric energy for each node relative to the cost of electric energy in the connection of the electric network. 3. The method according to claim 1 or 2, characterized in that the calculation of the value representing the amount of electrical energy transferred from the connection of the electrical network and nodes to subsequent nodes, includes:
(a) determining the amount of electrical energy delivered to the final node N _N , based on the power consumption of the specified node;
(b) determining the loss in elements for the connection between the node N _N and the previous node N _N-1 ; (c) calculating the total amount of electric energy transmitted to the node N _N from the connection point of the previous node N _N-1 , based on the amount of electric energy delivered to the node N _N and losses between the nodes N _N and N _n-1 ; (d) determining the amount of electric energy used in the previous node N _N-1 , based on the power consumption of the specified node, and then calculating a value representing the amount of electric energy transmitted to the node N _N-1 by summing the amount of electric energy used in the node N _N-1 , and the amount of electrical energy transmitted to the node N _N ; (e) repeating steps (b) to (d) for node N _N-1 and previous nodes to determine a value representing the amount of electrical energy transferred to each node from the corresponding previous node, before moving to node N ₁ and, thus, determining a value representing the amount of electrical energy transmitted from the connection points of the nodes N ₁ -N ₂ ; and
(e) calculating a quantity representing the amount of electric energy transmitted to the node N ₁ from the connection of the electric network based on the amount of electric energy delivered to the node N ₁ and the loss of connection between the connection of the electric network and the node N ₁ . 4. The method according to claim 3, characterized in that the losses in each node relative to the connection of the electric network are estimated by: (g) calculating the ratio "P / P" for each node, and for the first node N _{1 the} ratio P / P is equal to the number of electric energy coming from the connection of the electric network, divided by the amount of electric energy delivered to the specified node, and for each node N ₂ -N _N , the P / P ratio is equal to the amount of electric energy leaving from the previous node, divided by the amount of electric energy, delivered Noah to the specified node; (h) calculating the ratio “P _trans / P" for each node, the ratio P _trans / P equal to the product P / P for this node and P / P for the previous node or P / P for connecting the electrical network in which this node is the first node is N ₁ , and the P / P ratio for connecting the electrical network is equal to one; and (i) determining the total loss for each node as P _trans / P minus 1. 5. The method according to claim 4, characterized in that the total losses are used to calculate the cost of electric energy for each node by: (k) calculating the cost in the first node N ₁ by multiplying the cost of electric energy in the connection of the electric network by the ratio P / P for node N ₁ ; and (k) calculating the cost in the next node N ₂ and each subsequent node by multiplying the value in the previous node by the P / P ratio for the node N ₂ and each subsequent node. 6. The method according to claim 1 or 2, characterized in that it includes storage of consumption and loss values for each node for use in determining network losses. 7. The method according to claim 1 or 2, characterized in that the electrical distribution network contains distribution networks with different voltage levels, and this method is repeated for the nodes of each voltage level of the network to monitor the entire network. 8. A method for monitoring a node N _x in an electrical distribution network having a plurality of nodes, including estimating the amount of electric energy consumed by the node N _x and determining power losses during transmission from the previous node N _x-1 ; receiving from the next node N _{x + 1} data regarding the amount of electrical energy transmitted from the node N _x to the specified node N _{x + 1} ; and calculating the amount of electric energy transmitted to the node N _x from the previous node N _x-1 based on the amount of consumed electric energy, the indicated power loss during transmission from the previous node N _x-1 and the amount of electric energy transferred to the next node N _{x + 1} , and transferring this value to the previous node N _x-1 . 9. The method according to claim 8, characterized in that it includes the calculation of the ratio "P / P" for the node N _x , and for the node N _{x the} ratio P / P is equal to the amount of electric energy leaving the previous node N _x-1 , divided by the amount of electrical energy delivered to the node N _x ; transfer of the P / P value for the node N _x to the next node N _{x + 1} ; receiving the P / P value for the previous node N _x-1 , and for the node N _x-1 , the P / P ratio is equal to the amount of electric energy leaving the previous node N _x-2 divided by the amount of electric energy delivered to the node N _x-1 ; the calculation of the ratio "P _trans / P" for the node N _x , and the ratio P _trans / P is equal to the product P / P for the node N _x and P / P for the previous node N _x-1 ; determining the total losses relative to the electrical network connection for the node N _x as P _trans / P minus 1. 10. The method according to claim 9, characterized in that it includes receiving the value of the cost of electric energy for each node from the previous node N _x-1 ; calculating the cost of electric energy in the node N _x by multiplying the cost of electric energy in the previous node N _x-1 by the ratio P / P in the node N _x ; and transmitting the value of the cost of electrical energy for the node N _x in the next node N _{x + 1} . 11. A device for monitoring a node N _x in an electrical distribution network having a plurality of nodes, comprising: a device for receiving data for receiving data from the next node N _{x + 1} regarding the amount of electric energy transmitted from the node N _x to said node N _{x + 1} ; a computing device configured to estimate the amount of electric energy consumed by the node N _x , determine the power loss during transmission from the previous node N _x-1 and calculate the amount of electric energy transmitted to the node N _x from the previous node N _x-1 , based on the quantity consumed electric energy, transmission losses and the amount of electric energy transferred to the next node N _{x + 1} ; and a data transmission device for transmitting data regarding the amount of electric energy transmitted to the node N _x from the previous node N _x-1 , to the previous node N _x-1 . 12. The device according to claim 11, characterized in that the computing device is configured to calculate the P / P ratio for the node N _x , and for the node N _x , the P / P ratio is equal to the amount of electric energy leaving the previous node N _x-1 , divided by the amount of electrical energy delivered to the node N _x ; the data transmission device is designed to transmit the P / P value for the node N _x in the next node N _{x + 1} ; a data receiving device is designed to receive the P / P value for the previous node N _x-1 ; moreover, for the node N _x-1 , the P / P ratio is equal to the amount of electric energy leaving the previous node N _x-2 divided by the amount of electric energy delivered to the node N _x-1 ; and the computing device is also configured to calculate the ratio P _trans / P for the node N _x , and the ratio P _trans / P is equal to the product P / P for the node N _x and P / P for the previous node N _x-1 , and determine the total losses relative to electrical network connections for node N _x as P _trans / P minus 1. 13. The device according to p. 12, characterized in that the data receiving device is designed to receive the value of the cost of electric energy for each node from the previous node N _x-1 ; the computing device is configured to calculate the cost of electrical energy in the node N _x by multiplying the cost of electrical energy in the previous node N _x-1 by the ratio P / P in the node N _x ; and the data transmission device is designed to transmit the value of the cost of electrical energy for the node N _x in the next node N _{x + 1} . 14. The device according to claim 11, characterized in that it is located in the node. 15. A device for monitoring an electrical distribution network containing an electrical network connection for transmitting electrical energy to a plurality of nodes N ₁ -N _N , wherein the electrical network connection is connected to a node N ₁ , and said nodes are connected in series, comprising a data processing device configured to the implementation of the method according to one of claims 1 to 10. 16. The device according to item 15, wherein the data processing device comprises a device according to one of paragraphs.11-14 for each node. 17. The device according to one of paragraphs.11-16, containing measuring means for determining the power consumption of a given node or each node. 18. A method of controlling an electrical distribution network containing an electrical network connection for transmitting electric energy to a plurality of nodes N ₁ -N _N , wherein the electric network connection is connected to a node N ₁ , and said nodes are connected in series, including: transmitting electric energy between an electric network connection and the first node N ₁ , and between each node and the next node; determining the consumption or production of electric energy in each node and the amount of electric energy transferred between the first node N ₁ and the connection of the electric network;
determination of losses in the transmission of electrical energy between the connection of the electrical network and the first node N ₁ , and between each node and the next node; and monitoring the electrical distribution network or the nodes contained therein using the method according to one of claims 1 to 10.

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