RU2800630C1 - System for monitoring the quality of electric energy by measuring electric power quantities and parameters - Google Patents

Abstract

FIELD: electrical measuring equipment.

SUBSTANCE: system for monitoring the quality of electric energy by measuring electric power quantities and indicators includes mechanisms for disconnecting the lines for the supply of electricity to the consumer from the lines of the centralized supply of electricity, which are interconnected through the means of connecting the lines in the area up to the entrance to the lines for the supply of electricity to the consumer and to each of which a device is connected for measurement of at least current, voltage and temperature, equipped with a means of transmitting data in the direction of the controller, configured for implementing the functions of shutting down the power supply line to the consumer when the readings deviate from those set for assessing the quality of electrical energy, shutting down the lines associated with the lines of the centralized supply of electricity, in case of deviation of the readings of measuring devices from those established for assessing the quality of electric energy and combining lines connected with lines of a centralized supply of electricity into a common line. The controller is connected to partial discharge sensors and is connected via wireless communication lines to the cloud data storage server for measurements, to the dispatcher's computerized workstation and to a separate server configured to implement the function of updating and restoring the controller's software systems and backup storage of data received from controller. Computerized user workstations and a customized service server are connected to the cloud storage server.

EFFECT: increasing the safety of functioning of power supply lines to end consumers by identifying sections of lines and electrical equipment with impaired operational parameters.

1 cl, 1 dwg

Description

The invention relates to means of electrical measuring equipment for accounting for the quality of electricity according to the recorded indicators of the electric power indicators of the network in the current time mode.

The quality of electrical energy is the degree of compliance of the parameters of electrical energy with their established values (GOST R 54130-2010. National Standard of the Russian Federation. Quality of electrical energy. Terms and definitions). In turn, the parameter of electrical energy is a quantity that quantitatively characterizes any property of electrical energy. Under the parameters of electrical energy understand the voltage, frequency, shape of the electric current curve. In Russia, indicators and standards for the quality of electrical energy in electrical networks of general-purpose power supply systems of three-phase and single-phase alternating current with a frequency of 50 Hz at the points to which electrical networks or electrical installations of consumers are connected are established by the Interstate standard GOST 32144-2013 "Electric energy. Electromagnetic compatibility of technical means. Standards for the quality of electrical energy in general-purpose power supply systems" (dated July 22, 2013 N 400-st).

In accordance with GOST 32144-2013, the main indicators of the quality of electrical energy are the following: steady-state voltage deviation, voltage swing, flicker dose, distortion coefficient of the sinusoidal voltage curve, coefficient of the n-th harmonic component of the voltage, voltage asymmetry coefficient in the negative sequence, asymmetry coefficient zero sequence voltage, frequency deviation, voltage dip duration, impulse voltage, temporary overvoltage factor.

In connection with the development of market relations in the electric power industry, electricity should be considered not only as a physical phenomenon, but also as a product that must meet a certain quality and market requirements. The Federal Law "On the Electric Power Industry" defines the responsibility of energy sales organizations and electricity suppliers to consumers for the reliability of their electricity supply and its quality in accordance with technical regulations and other mandatory requirements ("Power Quality Management" I. I. Kartashev, V. N. Tulsky , R. G. Shamonov and others, under the editorship of Yu. V. Sharov, M, MPEI Publishing House, 2006).

Currently, there are quite a few circuit solutions for controlling energy resources in terms of their distribution and control over the main parameters of the flows of resources provided.

Thus, there is a well-known measuring and computing complex for accounting and managing energy resources, containing primary measuring converters of energy resources of approved types: electronic electricity meters, heat meters, flow meters-meters of various liquids, analog current and voltage sensors, programmable controllers based on MK microcontrollers based on a PIC single-chip microprocessor 16F877/201P with EEPROM with a sufficiently large number of discrete and analog inputs to create measuring channels of an integrated energy accounting and management system with wired communication lines that allow each primary measuring transducer to be connected directly to a discrete or analog input of the MK microcontroller, radio modem, radio station, server, dispatcher workstation, workstations, non-contact power switch, software, wired communication lines, and for the power supply of functional circuits of discrete and analog inputs and outputs of the MK microcontroller, a main power supply circuit was used, providing power from a centralized power source of independent sources autonomous power supply of galvanically isolated inputs and outputs of the microcontroller MK (RU 18313, G01R 22/00, publ. June 10, 2001).

The disadvantage of this solution is the low reliability of the received indicators due to the use of analog readout nodes and the limited possibilities of using the complex due to the use of wired communication types.

The use of a multimedia system for monitoring and managing energy resources makes it possible to increase the accuracy and reliability of the transmitted indicators. Such a system contains a data collection and transmission device connected via a bidirectional public access communication channel with unique identification addresses to the second input of each specialized meter-computer of consumed electricity, workstations based on personal computers, a server, a computer-collector, a central control room and "n" structurally identical local information-measuring blocks of control, accounting

and management of energy resources associated with a data collection and transmission device connected to a computer-collector connected to workstations based on personal computers, to a server and to a central control room (RU 2474827, G01R 11/42, publ. 21.07.2011) .

In this system, each local information-measuring unit for monitoring, accounting and managing energy resources includes a series-connected power electrical network, a specialized counter-computer of consumed electricity, a module for forced shutdown of the power supply, a consumer load, and an information block associated with a device for collecting and transmitting data and control and with the switching unit of external devices and connected to the information display unit and to the input-output panel, while the second output of each specialized counter-computer of the consumed electricity is connected via a bidirectional public communication channel with unique identification addresses with the second input of the corresponding module for forced shutdown of the supply electricity.

The disadvantage of this solution is that it most likely solves the problem of monitoring the consumption of energy resources to identify entities that do not pay for the service and to disconnect them from consumption lines.

This explains the introduction of means of switching supply networks into the system and the fact that it can be used in housing and communal services.

Known system, which is a multifunctional, three-level hierarchical structure, consisting of measuring, connecting and computing components that form the measuring channels. The first level consists of primary measuring components that measure the parameters of the coolant, electricity, continuously or discretely, with the required time interval. At the second level of the system, measuring transducers are used to receive measuring information from primary measuring components, followed by data transmission via radio channels, industrial network communication lines and Ethernet networks, their archiving and transmission on request to the server and automated operator workstations. The third (upper) level of the system is a server and/or operator workstation with the function of a computer-based archival database server with specialized software (RU 83829, F24D 1/00, published on 06/20/2009).

This solution describes the hierarchical structure of building automated systems for monitoring the state of electricity supply systems and collecting and processing information on the consumption of electricity provided.

As a prototype, a three-level automated system for technical accounting of power quality was chosen, which includes active and reactive energy meters of traction substations, a data collection and transmission unit, an information collection and integration unit, from a device for simulating the operation of a traction power supply system, consisting of a storage unit for passport and reference database block of parameters of the traction power supply system, block of the database of track development of sections of the polygon, block of the database of current characteristics, block of the database of speed characteristics, block for calculating the traction power supply system, block for constructing instantaneous schemes, block for correcting the operation of the system, block for monitoring the adequacy of work of the system, a block for determining power losses, a block for determining traction power consumption and from a device for monitoring train operation on a section, an additional block for measuring power quality indicators is additionally introduced, which is connected in series with the input of the block for collecting and integrating information, in which, in turn, two outputs are additionally made , in the device for simulating the operation of the traction power supply system of the automated system, a block for monitoring and predicting indicators of power quality was introduced, which has one output and two inputs, one of which is connected to the output of the block for determining traction power consumption, and the second - to the output of the block for collecting and integrating information of the technical device metering of electricity, a block for predicting traction power consumption is additionally introduced into the train operation control device at the site, which is connected by one input to the block for predicting train operation of the same device and by two inputs is connected to the blocks for determining traction power consumption and calculating the traction power supply system of the device for simulating the traction power supply system. (RU 80600, G06F 17/00, published on June 16, 2008).

The disadvantage of this system lies in its design complexity due to the fact that it includes meters of active and reactive energy of traction substations, a device for simulating the operation of the traction power supply system, consisting of a block for storing passport and reference data, a database block for the parameters of the traction power supply system , block of the database of track development of the polygon sections. In this solution, an attempt was made to combine the system for monitoring the parameters of the functioning of traction substations, which are sources of electricity supply to the lines supplying the consumer, and the system for accounting and consumption of electricity in these lines. Thus, the solution establishes a dependent relationship between the operation of the traction substation system and the parameters of electricity consumption.

At present, the conditions have been formed according to which the functioning of substations in terms of issuing electricity to the consumer of the normatively established quality is not related to the specifics of the functioning of systems for accounting and consumption of electricity and its consumption in the volume normalized for these systems. Therefore, linking two different systems leads to the fact that one system begins to depend on the other. The patent states that the patented system has enhanced capabilities by reducing equipment failure rates, reducing damage from power outages, reducing losses and current loading of equipment before and after applying reactive power compensation, which leads to a reduction in losses by 2-3%.

If we take into account that reactive power compensation means a targeted impact on the balance of reactive power in a node of the electric power system in order to regulate voltage, and in distribution networks in order to reduce power losses, then it can be seen that this compensation is carried out using compensating devices. To maintain the required voltage levels in the nodes of the electrical network, the consumption of reactive power must be provided by the required generated power, taking into account the necessary reserve. As a result, it can be seen that the loss in the quality of electricity parameters in this system is compensated by the issuance of backup voltage from traction substations. But such a solution does not ensure the elimination of the causes of changes in the quality of electricity in the lines of their delivery to the final consumer and does not reveal the points of occurrence of defects on the lines in which this change occurs. Any change in the quality parameters on the line is the result of the destruction of the line section, which can ultimately lead to line breakage. This line state is ignored. Therefore, this system does not fully ensure the safety of the state of the lines for the issuance of electrical energy to the consumer. Reactive power compensation by recharge from the reserve is a temporary solution to keep the line in the required state until it is completely destroyed due to the disregard for the appearance of partial discharges, which are the result of the destruction of the insulation of the current-carrying line.

The present invention is aimed at achieving a technical result, which consists in improving the safety of the operation of power supply lines to end consumers by monitoring the quality parameters of the supplied energy and identifying sections of lines and electrical equipment that are losing operational parameters.

The specified technical result is achieved by the fact that the system for monitoring the quality of electric energy by measuring electric power quantities and indicators includes devices for collecting primary information, each of which is connected to the line for issuing electricity to the consumer, includes sensors for measuring at least current, voltage and temperature and equipped with a means of data transmission in wired or wireless modes in the direction of the controller, with which the mechanisms for disconnecting the lines for issuing electricity to the consumer are connected from the lines of the centralized supply of electricity, which are interconnected through the means of connecting the lines in the area up to the entrance to the lines for issuing electricity to the consumer and with each of which a device for measuring at least current, voltage and temperature is connected, equipped with a means of transmitting data in wired or wireless modes in the direction of the specified controller, configured to implement the functions of shutting down the power supply line to the consumer when the readings of the primary information collection device deviate from those set for assessing the quality of electrical energy , disconnecting the lines associated with the lines of the centralized supply of electricity, when the readings of the device for measuring at least current, voltage and temperature deviate from those set for assessing the quality of electric energy and combining the lines associated with the lines of the centralized supply of electricity into a common line, while the controller is connected with partial discharge registration sensors and via wireless communication lines is connected to the server of the cloud data storage for measurements, to the dispatcher's computerized workstation and to a separate server configured to implement the function of updating and restoring the controller software systems and backup storage of data received from the controller, connected to the unit of autonomous independent power supply and protection against power failures, and the computerized user workstations, the computerized workstation of the dispatcher and the server of the customized service are connected to the cloud storage server via wireless communication lines.

These features are essential and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the desired technical result.

Figure 1 is a block diagram of the system for monitoring the quality of electrical energy by measuring electric power quantities and indicators.

According to the present invention, a new system for monitoring the quality of electric energy by measuring electric power quantities and indicators is considered, which is used to identify primary (beginning to appear) functional violations in order to maintain the viability of equipment and lines for supplying electric energy to the end consumer and to eliminate emergency situations with these lines and equipment.

The claimed invention is considered on the example of standard systems 1, consisting of a power plant, step-up substation, power lines 2, step-down substation, switchgear and consumer 3. A feature of such a system is that the longer the line 2, the greater its resistance. According to the Joule-Lenz law, power is directly proportional to resistance. That is, the greater the resistance, the greater the losses in the line. Reducing losses in the power line can be done in two ways: by increasing the cross section of the line wire, then the resistance will decrease and the loss will decrease, or by increasing the network voltage. But if you increase the cross section of the wire, it greatly increases the cost of it. It became more profitable to increase the voltage.

Power lines are divided into overhead and cable lines. Air are located above the ground on supports. Cable lines are carried underground, they have both external and inter-core insulation. Power lines run from the step-up transformer, for example, with a voltage of 220 kV. It is transmitted via power lines to a substation with a switchgear, this substation is already stepping down.

The switchgear can be for several voltages: 6, 10 or 35 kV, that is, from 220 kV, the transformer substation reduces the voltage to 6, 10 or 35 kV. From the switchgear, as a rule, not by air, but by cable lines, electricity is distributed to one or more sections. The cable line goes to the distribution point, the busbars of which are energized. The purpose of this substation is to reduce the voltage to 0.4 kV. From the transformer substation, cable lines go to the input switchgear of a residential building or switchboards of a workshop or any enterprise.

Technological losses of electricity during its transmission through electric networks include technical losses in the lines and equipment of electric networks due to physical processes occurring during the transmission of electricity in accordance with the technical characteristics and modes of operation of lines and equipment, taking into account the consumption of electricity for substation own needs and losses due to permissible errors in the electricity metering system.

Under the technical losses in the power supply lines of consumers are understood the losses caused by the emergency condition of the lines, which is determined by the presence of a partial discharge (PD). PD is a short-term ultra-low power discharge that occurs inside or on the surface of the insulation of high-voltage cables. Also, a partial discharge can also occur on the housings of power plants of high or medium voltage classes. A single PD does not entail any special danger - it is a short event that cannot harm the cable. But, occurring on a regular basis, such discharges lead to the destruction of the insulation, and as a result, to a short circuit. As a result of PD, the following phenomena are observed: the appearance of a pulsed current, electromagnetic radiation into the environment, light radiation and the decay of insulation and the appearance of cracks in it. Most often, partial discharges are observed in places of insulation inhomogeneity. Inclusions of slags and impurities, air voids or liquid droplets - all these are places of increased risk of PD. And taking into account the fact that such discharges provoke damage in the cable line, the worse the condition of the line, the more often partial discharges occur on the site. In addition, it should be taken into account that the measuring equipment does not measure each PD separately, but operates with the total charge flowing per unit time. Such a charge is the sum of all the discharges that occurred during the measured period.

Under the action of an electric field, aging mainly occurs due to the development of PD in the insulation. PDs occur in gas inclusions in the thickness of the insulation (the electrical strength of gas bubbles is lower than the strength of a solid dielectric, and the electric field strength in a gas bubble at an alternating voltage is higher than in a solid dielectric). In the manufacture of insulation, special measures are usually taken against the appearance of gas inclusions, but despite this, one has to reckon with the possibility of their accidental formation at the manufacturing stage (due to imperfection of the drying and impregnation processes) or in operation (the appearance of cracks during mechanical overloads, the release of gases during decomposition materials due to local overheating, etc.). Overheating of the insulation leads to an acceleration of the process of its destruction due to an increase in the number of points at which new defects appear, leading to an increase in the number and volume of dendrites. PD has a thermal effect on the insulation, and also destroys it with charged particles and chemically active products resulting from the discharge. In addition, PDs cause the appearance of pulsed currents in the channels they create. During a breakdown, all this is accompanied by electromagnetic radiation, shock waves, light flashes and the breakdown of insulation at the molecular level. PDs are among the main causes of equipment damage. This is explained by the fact that the appearance of a PD is the initial stage in the development of most defects in high-voltage insulation.

The claimed system (figure 1) is intended to improve the safety of the operation of lines 2 supplying electricity to end consumers 3 by monitoring the quality parameters of the supplied energy and identifying sections of the lines that are losing operational parameters, where deviations in the quality of electricity parameters are detected.

Such a system includes devices 4 for collecting primary information related to such parameters as current, voltage and temperature. Each of these devices is connected to the line 2 for the supply of electricity to the consumer and includes sensors for measuring at least current, voltage and temperature. Each device 4 is equipped with a means of transmitting data in wired or wireless modes in the direction of the controller 5. The sensors 6 for detecting partial discharges are also connected via wireless communication lines, which operate according to the radio wave method (based on the detection of radio interference caused by PD, the place of the highest concentration interference will be the place of occurrence of the PD). During normal operation of the line, a stable background of electromagnetic radiation is created around it, which is accepted as neutral. This background is periodically read by sensors 6 when monitoring lines 2. This neutral background is entered into the controller as a reference level. In the normal operation of the device 4 at a given interval, the readings of the quality parameters of the electricity supplied to the consumer are taken. If these parameters go beyond the limits of the limit values established by the regulations (for example, GOST 32144-2013), then these deviations are signs of defects in the lines. When establishing the signs of a defect, the line is scanned by sensors 6 (PR) to determine the places of deviation of the electromagnetic disturbance from the background level.

Practice shows that a low-level PD is a normal manifestation of the line operation, these signals appear periodically with an unspecified time interval. Critical PDs are those that have a significant range in amplitude, and their frequency of occurrence is reduced in time. When 10 or more such critical PDs are detected in a short period of time or an interval decreasing in time, the controller generates a command to detect an emergency (even if the line continues to function at the time of registration of critical PDs).

The controller is designed for:

- measurement and registration of the main indicators of power quality (PQE) established by GOST 32144-2013;

- measurement and registration of the main parameters of electrical energy (PEE) in single-phase and three-phase electrical networks (effective values of voltages and currents with sinusoidal and distorted waveforms; active, reactive and apparent electrical powers, supply voltage frequency, cosFi, electrical energy accounting);

- tire and ambient temperature measurements;

- measurements of partial discharges;

- indication of the measured values and presentation of information in a form convenient for the operator;

- indication of oscillograms of currents and voltages;

- transferring information to the operator's workstation in a form convenient for analysis and perception via the IEEE 802.3 (Ethernet) interface, using a GSM modem;

- transferring information to a cloud storage server for its subsequent processing and storage via the IEEE 802.3 (Ethernet) interface and via a GSM modem

- obtaining, processing and storing information on the measurement and registration of SCE and PEE, temperature, etc. from related meters (data collection devices) via wired or wireless Ethernet, RS485, Wi-Fi, LoRaWAN, etc.

- control of automatic switches or contactors; reading information from microprocessor automatic switches, their control and management;

preventive diagnostics of electrical equipment; analysis and forecast of emergency and pre-emergency situations.

In each line 2 there are mechanisms 7 for disconnecting the lines for issuing electricity to the consumer from the lines of the centralized supply of electricity, which are interconnected through a means for connecting lines in the area before entering the lines for issuing electricity to the consumer. These mechanisms 7 are wired or wirelessly connected to the controller 5. The controller 5 is configured to implement the functions of turning off the power supply line to the consumer when the readings of the primary information collection devices 4 deviate from those set for assessing the quality of electric energy.

The controller 5 is also connected to the mechanism 8 in the form of a switch for combining lines into a common line. When one of the lines is turned off due to its emergency condition, sections of the lines for issuing to the consumer can be connected to a working line or to a backup line using this switch.

In addition, the controller is connected to nodes 9 in the form of a mechanism for disconnecting lines in the area from the points of electricity supply to the consumer and to the points (locations) of the devices 4 for collecting primary information.

Thus, from the point of connection of lines 2 to the centralized power supply source to the points of issuance of this electricity to the consumer, the system is equipped with switching (switching off) mechanisms controlled by the controller 5 via, for example, modem connection 10, to disconnect that section of the lines, the power quality parameters for which are confirmed radio wave characteristics of the pattern of electromagnetic disturbances. This allows preventive measures to identify sections of lines in respect of which the likelihood of failures and accidents increases, and proactively turn off these sections with their transfer to the repair and recovery mode.

The controller is connected via a wireless communication line (via modem 11) with the server 12 of the cloud data storage for measurements, with a computerized workstation 13 of the dispatcher and with a separate server 14 (service server), configured to implement the function of updating and restoring the software systems of the controller and backup storage of data received from the controller.

AWP cloud storage server provides:

1) periodic and (or) on request automatic collection of measurement results;

2) automatic collection of data on the state of measuring instruments from all additional components serviced by this controller, and the state of measurement objects (if there is automatic collection of information on the state of measurement objects);

3) automatic collection of measurement results and data on the state of measuring instruments from all devices interrogated by the controller and the state of measurement objects (if there is automatic collection of information on the state of measurement objects) after the restoration of the communication channels, restoration of power supply;

• formation and transmission of measurement results and data on the state of measurement objects (in the presence of automatic collection of information on the state of measurement objects);

4) remote access from the workstation to the controller components;

5) hardware and software protection against unauthorized modification of parameters and any modification of data;

6) configuration and parameterization of hardware and software.

The controller is a programmable complex connected to the unit 15 of autonomous independent power supply and protection against power interruptions, which maintains the operability of the complex in the event of an emergency state of the centralized power supply system. The complex is connected with a block 16 of auto-recovery, self-diagnosis and auto-update, a block 17 of controlling the temperature of the cabinet where the controller is located, and a bright flash, as well as opening the cabinet, a block 18 of blocking the cabinet opening mechanisms

And with the cloud storage server 12, computerized user workstations 19 and a customized service server 20 are connected via wireless communication lines.

Thus, within the framework of the present invention, the controller is used for energy inspection of enterprises - producers and consumers of electrical energy, technological control and analysis (monitoring) of energy parameters and quality of electrical energy, accounting for electrical energy and monitoring the temperature of tires, the environment, etc., technical control and analysis of the level of partial discharges.

Claims (1)

The system for monitoring the quality of electric energy by measuring electric power quantities and indicators, characterized in that it includes devices for collecting primary information, each of which is connected to the line for issuing electricity to the consumer, includes sensors for measuring at least current, voltage and temperature and is equipped with a means data transmission in wired or wireless modes in the direction of the controller, with which the mechanisms for disconnecting the lines for supplying electricity to the consumer are connected from the lines of the centralized supply of electricity, which are interconnected through the means of connecting the lines in the area up to the entrance to the lines for supplying electricity to the consumer and with each of which a device is connected measurement of at least current, voltage and temperature, equipped with a means of transmitting data in wired or wireless modes in the direction of the specified controller, configured to implement the functions of shutting down the power supply line to the consumer when the readings of the primary information collection device deviate from those set for assessing the quality of electrical energy, shutdown lines connected to the lines of the centralized supply of electricity, when the readings of the device for measuring at least current, voltage and temperature deviate from those set for assessing the quality of electric energy and combining the lines associated with the lines of the centralized supply of electricity into a common line, while the controller is connected to the sensors registration of partial discharges and is connected via wireless communication lines to the server of the cloud data storage for measurements, to the computerized workstation of the dispatcher and to a separate server configured to implement the function of updating and restoring the controller software systems and backup storage of data received from the controller that is connected to the block of autonomous independent power supply and protection against power failures, and the computerized user workstations, the computerized workstation of the dispatcher and the server of the customized service are connected to the cloud storage server via wireless communication lines.

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