Electromagnetic recuperator of reactive power with cooling

Abstract

The utility model relates to the field of electrical engineering, namely to devices for converting and regulating reactive power in alternating current networks. The technical result achieved through the implementation of the utility model consists in ensuring the safe operation of an electromagnetic reactive power recuperator. The electromagnetic reactive power recuperator for connection to a three-phase alternating current network comprises a housing, a first block of capacitors connected in a delta pattern in parallel, a three-phase choke, and a second block of capacitors connected in a delta pattern in parallel, wherein the three-phase choke and the second block of capacitors are connected via semiconductor switches in each phase, and also comprises an input contactor, temperature sensors for the power cable, the three-phase choke, and the air inside the recuperator housing, as well as a telemetry module connected to the said temperature sensors and the input contactor. 3 c.p. f-y. 1 ill.

Description

[0001] The utility model relates to the field of electrical engineering, namely to devices for converting and regulating reactive power in alternating current networks in order to reduce electricity losses, reduce the load on electrical networks and improve the quality of power supply.

[0002] The prior art discloses devices for increasing the efficiency of using electrical energy in a power supply network, converting reactive power to supply a load. A reactive power compensation device is known, comprising a three-phase cosine capacitor and a contactor including contacts and a control element for them, wherein the outputs of the three-phase capacitor are connected to the inputs of the contactor, the outputs of which are connected to a three-phase electrical network, characterized in that a contactor switching unit is included therein, the inputs of which are connected to the outputs of the three-phase capacitor, and the output is connected to the control element for the contacts of the contactor, wherein the power input of the contactor switching unit is connected to one of the phases of the electrical network [RU Patent No. 75517, IPC H02J 3 / 18, published 10.08.2008].

[0003] A half-period generator is known, comprising a three-phase inductor coil with steel, a load, thyristors and capacitors, characterized in that the capacitors, connected in a triangle, are connected in parallel to a three-phase alternating current source, to which a three-phase inductor coil with steel, other capacitors connected in a triangle, capacitors connected in a star, and a load are also connected in parallel via thyristors [RU Patent No. 197031, IPC H02M 7 / 155, published 03 / 26 / 2020].

[0004] A neutral current modulator is known, containing diodes, a three-phase inductor with steel, capacitor banks, a transistor, active loads and a control system, characterized in that the three-phase inductor with steel is connected in parallel to a three-phase AC voltage source, through diodes in each phase connected in series to the three-phase inductor with steel, one capacitor bank, connected in a triangle, is connected in parallel to the three-phase AC voltage source, the second capacitor bank, connected in a star, is connected in parallel to the three-phase inductor with steel, the transistor, together with one of the active loads, are connected in series with each other and with the neutrals of the three-phase AC voltage source and the three-phase inductor with steel, three other identical active loads are connected in parallel to the diodes [RU Patent No. 170594, IPC H02M 7 / 06, publ. [02.05.2017].

[0005] The closest analogue (prototype) is known - a reactive power compensator, comprising a housing in which a voltage and current monitoring unit is placed, as well as at least one block of capacitors connected in a triangle, configured to be connected in parallel to an electrical load, a three-phase current choke with a star connection of windings and at least one block of capacitors connected in a triangle, configured to be connected to an electrical load through at least one power semiconductor switch in parallel to each other, wherein the neutral of the three-phase current choke is configured to be connected to the neutral of the supply transformer through a rheostat with variable resistance [RU Patent No. 230975, IPC H02J 3 / 18, published. 12 / 26 / 2024]. The disadvantage of the known solutions is the lack of overheating protection.

[0006] The technical problem addressed by the development of this utility model is the need to increase the reliability and efficiency of an electromagnetic reactive power recuperator, as the following transient operating conditions may occur during its operation: when load parameters change, the reactive component may increase, leading to increased heating of the choke coils. Overheating of the choke coils can lead to degradation and destruction of the winding wire insulation, ultimately leading to a short circuit. During prolonged operation of the device at elevated temperatures, the capacitors inside the housing overheat, causing them to dry out and lose capacity. Furthermore, overheating negatively impacts the performance of the recuperator.

[0007] The technical result achieved in the implementation of the utility model consists in increasing the reliability and efficiency of the electromagnetic recuperator of reactive power, which is ensured by reducing the negative impact of overheating of the choke and the entire device as a whole during transient operating modes of the electromagnetic recuperator.

[0008] The essence of the utility model is expressed in the following set of essential features: an electromagnetic recuperator of reactive power for connection to a three-phase alternating current network, comprising a housing, a first block of capacitors connected in a triangle in parallel, a three-phase choke and a second block of capacitors connected in a triangle in parallel, wherein the three-phase choke and the second block of capacitors are connected through semiconductor switches in each phase, characterized in that it contains a heat exchange circuit with terminals for connection to an external heat exchange circuit.

[0009] The stated combination of essential features enables the claimed technical result to be achieved, as it ensures reliable and efficient operation of the electromagnetic reactive power recuperator by removing excess thermal energy generated during operation under certain transient conditions from the inductor and the housing of the claimed device as a whole. The first block of capacitors, connected in a delta-parallel configuration, and the three-phase inductor connected via semiconductor switches in each phase, as well as the second block of capacitors, connected in a delta-parallel configuration, form a reactive power filter that compensates for reactive energy, increasing the power factor, thereby reducing energy losses, reducing the load on the power grid, and improving the quality of the power supply.

[0010] The drawing (figure) shows a block diagram of one example of the implementation of the utility model - an electromagnetic recuperator of reactive power with cooling.

[0011] 1 - Body

[0012] 2 - Contact group for connection to a three-phase network

[0013] 3 - Contact group for connection to the load

[0014] 4 - The first block of capacitors connected in a triangle in parallel

[0015] 5 - Semiconductor switches

[0016] 6 - Second block of capacitors connected in a triangle in parallel

[0017] 7 - Throttle

[0018] 8 - Heat exchange circuit

[0019] 9 - Terminals for connection to an external heat exchange circuit.

[0020] In this example, the electromagnetic reactive power recuperator comprises a housing 1, a contact group 2 located on the outer part of the housing for connection to a three-phase network (A, B, C, N), a contact group 3 for connection to a load in the form of a single device (electric motor, welding machine, etc.), or in the form of a complex of consumers (for example, a production workshop). It also contains: a first block of capacitors 4, connected in a delta in parallel, semiconductor switches in each phase 5, a second block of capacitors 6, connected in a delta in parallel, a three-phase choke 7, which together form a reactive power extraction filter, acting as an LC filter, creating increased harmonics in the three-phase circuit. The semiconductor switches in each phase 5, implemented in this example in the form of a diode assembly, pass a positive half-wave, which is fed to the circuit formed by the coils of the choke 7 and the capacitors of the second block of capacitors 6.When the voltage sign changes, a negative self-induction current is induced in the circuit. Since this current pulse is more negative than the input current at semiconductor switches 5, semiconductor switches 5 pass a portion of the electrical energy back to the AC source and the load connected to contact group 3. The first block of capacitors 4, connected in a delta pattern in parallel to the three-phase AC source, serves as a compensator within the reactive power filter, regulating the extraction of reactive power. In this example, the electromagnetic reactive power recuperator is equipped with a heat exchange circuit 8 in the form of a radiator with terminals 9 for connection to an external heat exchange circuit, located in close proximity to the choke coils. Heat exchange circuit 8 can also be implemented as a tube encircling the choke coils, with terminals for connection to an external heat exchange circuit.The external heat exchange circuit can be an external radiator, or a building's heating system with a pump or natural circulation of the coolant. If an electromagnetic recuperator is used at a production site, the external heat exchange circuit can be used for heating in the production process.

[0021] The second capacitor block can consist of several capacitor banks connected in a triangle in parallel and contain power contactors and a telemetry module, which allows for automatic or forced connection and disconnection of capacitor banks depending on the parameters of the supplied load.

[0022] The electromagnetic recuperator may also include an input contactor, temperature sensors, and a telemetry module connected to the aforementioned temperature sensors and the input contactor. The telemetry module receives data from the temperature sensors connected to it, which may be located on the power cable, in the three-phase choke, or inside the recuperator housing. The telemetry module refers to the device element that reads parameters (in this case, temperature) and is capable of sending control commands to other device elements (input contactor, heat exchanger circuit pump), configured to transmit data to a control center, which may be a remote server with standalone software or a remote control workstation. Data transmission may be accomplished via a built-in wireless communication unit, an external antenna connected via a connector, or wired communication, including fiber optics.Based on the received data, control signals are generated to activate the heat exchanger circuit pump and disconnect the input contactor in the event of excessive overheating. Control software can also be stored directly in the telemetry module.

[0023] Thus, the utility model ensures the reliability and efficiency of the electromagnetic reactive power recuperator.

Claims

1. An electromagnetic regenerative power recuperator for connection to a three-phase alternating current network, comprising a housing, a first block of capacitors connected in a triangle in parallel, a three-phase choke and a second block of capacitors connected in a triangle in parallel, wherein the three-phase choke and the second block of capacitors are connected through semiconductor switches in each phase, characterized in that it contains a heat exchange circuit with terminals for connection to an external heat exchange circuit, wherein the heat exchange circuit is made in the form of a tube encircling the choke coils.

2. An electromagnetic recuperator of reactive power according to paragraph 1, characterized in that the second block of capacitors consists of capacitor banks connected in a triangle in parallel.

3. An electromagnetic recuperator of reactive power according to paragraph 1, characterized in that diodes are used as semiconductor switches in each phase.

4. An electromagnetic regenerative power recuperator according to paragraph 1, characterized in that it contains an input contactor, temperature sensors, and a telemetry module connected to said temperature sensors and the input contactor.

Images