RU217285U1 - HYBRID ELECTRICITY STORAGE FOR DC TRACTION POWER SUPPLY SYSTEM - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used in a DC traction power supply system for electrified railway transport, namely, at traction substations or linear devices of a DC contact network. The purpose of the utility model is to improve the energy efficiency of the DC traction power supply system containing a hybrid energy storage device. The proposed device makes it possible to reduce power losses in the traction power supply system by controlling a hybrid power storage device in charge and discharge modes, taking into account the energy performance of traction substations.

Description

The utility model relates to the field of electrical engineering and can be used in a DC traction power supply system for electrified railway transport, namely, at traction substations or linear devices of a contact network.

The purpose of the utility model is to improve the energy efficiency of the DC traction power supply system containing a hybrid power storage device.

The proposed device makes it possible to reduce power losses in the traction power supply system and implement control of various types of power storage devices when they work together in charge and discharge modes, taking into account the energy performance of adjacent traction substations.

There are various technical solutions for the use of energy storage devices in power supply systems that implement various mechanisms of charge and discharge.

The disadvantage of such devices is the inability to control the operating characteristics of the converter in the charge and discharge mode, taking into account the energy performance of adjacent substations of the DC traction power supply system.

Known device charge-discharge capacitive energy storage [1], which uses a capacitive storage, two smoothing devices and bidirectional converter control system. The technical result is achieved through the use of two controlled bidirectional DC/AC and AC/DC voltage converters, a transformer, a rectifier-inverter converter, and an automatic regulation and control system for an electric power storage device. The disadvantages of this scheme are: the inability to ensure joint operation of drives with different characteristics; increased power losses in a high-voltage bidirectional converter during voltage rectification; the inability to control the characteristics in the charge and discharge mode; the inability to adjust the performance depending on the energy performance of adjacent power supplies of substations.

A device is known for sectioning DC with a hybrid energy storage device [2], containing a capacitive and electrochemical energy storage device, two static converters, current and voltage sensors, a smoothing device and a control system. The technical result is provided by two different types of electric power storage devices, control of converters and placement of the device at traction substations or in the traction power supply system. The disadvantage of this scheme is the lack of galvanic isolation, which increases the reliability of operation, and operation with increased losses in bidirectional controlled converters, the inability to adjust the performance depending on the energy performance of adjacent traction substations.

A device (prototype) of a hybrid power storage device for a DC traction power supply system [3] is known, containing two power storage devices, two low-voltage bidirectional converters, a converter transformer, two high-voltage converters, filters, smoothing reactors, current and voltage sensors, an alarm and protection unit, automatic control system. The technical result is achieved through the use of active topology on the low voltage side and control depending on the voltage level on the buses to which the device is connected. The disadvantage of this solution is the absence of a body for regulating the operating characteristics of the device in the charge and discharge mode, depending on the load level and voltage on the buses of adjacent traction substations.

The proposed device can be used at traction substations, linear devices (sectioning posts and parallel connection points) of a 3.3 kV DC traction power supply system, on board an electric rolling stock when using hybrid power storage systems to improve the energy efficiency of the traction power supply system.

The converter of the hybrid electric power storage device ensures coordination of its operation with the DC traction network, regulation of the characteristics in the charge and discharge mode, coordination of the joint operation of various types of electric energy storage devices, ensuring galvanic isolation from the traction network and reducing electricity losses. Depending on the load level and voltage on the buses of adjacent traction substations, the operating characteristics of the device are regulated in charge and discharge modes.

The technical result is achieved by including in the device additional units for transmitting measurements, telemetry and telemechanics and connecting the unit for transmitting measurements to the existing automatic control system.

The claimed device consists of voltage sensors 1, 3 and 5, current sensors 2, 4 and 6, an alarm and protection unit (BSiZ) 7, an automatic control system unit (ACS) 8, an electrochemical type storage device (NEHM) 9, an electric storage type ( NET) 10, low-voltage filtering devices 11 (F1) and 12 (F2), bidirectional AC/DC converters 13 (P1) and 14 (P2), converter transformer (PT) 15, high-voltage inverter (P3) 16 and rectifier converters and 17 (P4), reactors (P1) 18 and (P2) 19, high-voltage filtering device (F3) 20, switching unit (BK) 21, connected to the substation buses or linear device (sectioning post (PS)) "+" bus 22 and "-" bus to rail.

Voltage sensors 1, 3 and 5 are connected to the output of the NEKhM and NET electric power storage devices from the low voltage side and to the output of high-voltage converters 16 and 17 on the higher voltage side from the contact network. The outputs of the voltage sensors 1, 3 and 5 are connected to the input of the SAR 8. The current sensors 2, 4 and 6 are connected to the outputs of the NEKhM and NET on the low voltage side and at the output of high voltage converters 16 and 17 on the high voltage side. The outputs of the current sensors 1, 3 and 5 are connected to the input of the ACS 8. The input-output pair of the BSIS 7 is connected to the input-output of the ACS 8. The outputs of the ACS 8 are connected to the inputs of the controlled transducers 13, 14 and 16, and the switching unit 21. Accumulators 9 and 10 are connected through filters to converters 13 and 14, which are connected to a converter transformer 15. A rectifier converter 17 and an inverter 16 are connected to the higher voltage winding of the PT 15, which are connected to the contact network through reactors 18 and 19 and a filter device 20. The output of the filter device 20 connected to the switching unit 21, then to the contact network through the buses of the substation or linear device (sectioning post)22.

The output of the measurement transmission unit (BPI) 23 is connected to the ACS input 8. The input of the BPI unit 23 is connected to the output of the telemetry unit (BTI) 24, the input of which, in turn, is connected to the telemechanics unit (BT). The inputs of the BT block are connected to the data transmission system (DTS).

The principle of operation of the claimed device is based on the operation of a DC/DC voltage converter with an AC link. With the help of ACS, the converters make it possible to implement various characteristics in the charge and discharge mode, depending on the traction load, the voltages on the substation or linear devices buses, the degree of charge of the storage devices and the depth of their discharge. By receiving real-time current and voltage measurement data from adjacent traction substations, the ATS adjusts the performance of the hybrid storage for charge and discharge modes depending on the load level and voltage.

In the charge mode, the electric power supplied to the device from the traction network (Fig. 1), through the buses of the substation or linear device (sectioning post) 22 and the switching unit 21, enters the filter device 20 and the inverter 16. The automatic control system 8 sends control signals for the opening of semiconductor switches depending on the voltage of the sensor 5, allowing you to generate an alternating voltage on the primary winding of the transformer 15, which is reduced to the required voltage level on the secondary winding. Then CAP 8, based on the measurement data of the voltage level (sensor 5) and current of the device (sensor 6), voltage sensors 1 and 3, current sensors 2 and 4, determines the degree of charge and the depth of discharge of the drives, the need to charge the drive of the first 9 and second 10 types , applying control pulses to the selected controlled bidirectional converter 13 or 14, respectively. The rectified voltage through low-voltage filtering devices 11 and 12 is supplied to the storage devices for charging.

In the discharge mode, the electricity supplied from the storage devices 9 and/or 10, depending on the discharge characteristics selected by the ATS 8, based on determining the degree of charge and the depth of discharge of the storage devices, measurements from voltage sensors 1, 3 and current sensors 2, 4, and the level load using a voltage sensor 5, as well as the incoming telemetry data from the BPI unit 23, is transmitted through low-voltage filtering devices 11 or 12 to a bidirectional converter 13 or 14, respectively.

On the basis of pulse-width modulation, low-voltage converters 13 or 14 provide the conversion of direct voltage into alternating voltage, which is supplied to the secondary winding of the transformer 15. The alternating voltage of the primary winding of the PT 15 is rectified using P4 17 and flows through the high-voltage filter device 20 and the reactor 19 to the contact and rail network, respectively.

Power control and regulation of the characteristics in the charge and discharge mode, based on the analysis of measurement data of the ACS of currents and voltages flowing in the circuits of the converter and adjacent substations, is implemented by selecting the operating mode of low-voltage converters 13 or 14 with drives 9 and 10.

Filtering devices 11, 12 and 20 make it possible to reduce the variable component in the charge and discharge currents flowing in the converter circuits. Reactors 18 and 19 are used to limit the circulating current in the rectifier-inverter circuit, to reduce the rate of rise of the inverter rollover current for stable operation of the protections.

Transformer 15 has two windings, the higher voltage winding has additional turns (for connecting inverter 16 with an increased transformation ratio), which makes it possible to reduce the unbalance of the inverted current in the charge mode.

As semiconductor devices in converters 13, 14 and 16, power lockable thyristors and transistors can be used, and in rectifier converter 17, uncontrolled semiconductor devices can be used to increase efficiency and reduce distortion of the rectified voltage curve.

Based on the current and voltage measurement data from adjacent substations coming to the ACS 8 from the BPI 23 unit connected through the telemetry units 24 and telemechanics 25 to the data transmission system, the performance characteristics of the converters are calculated and corrected according to the level of traction load within the boundaries of the intersubstation zone and the determination voltage losses in the contact network.

The advantage of the proposed device is the ability to regulate its performance in the charge and discharge mode and increase energy efficiency, taking into account the electric traction load within the boundaries of the inter-substation zone and voltage losses from the buses of adjacent substations to the proposed device.

Bibliographic list

1. Pat. RU (11) 158492 (13) U1. MPK N01M 10/44 Charge-discharge device for capacitive energy storage / Yu.V. Moskalev No. 2015118763/07; Claimed 05/19/2015; Published 01/10/2016. Bull. No. 1.

2. Pat. RU (11) 182831 (13) U1. MPK V60M 3/00 DC sectioning post with hybrid energy storage / V.L. Nezevac, B.T. Cheremisin, A.P. Shatokhin No. 2017144925; Claimed 12/20/2017; Published 09/04/2018. Bull. No. 25.

3. Pat. RU (11) 202369 (13) U1. IPC V60M 3/06 (2021.01). H01M 10/44 (2021.01). Hybrid energy storage device for direct current traction power supply system / V.L. Nezevak, V.T. Cheremisin, S.S. Samolinov. No. 2020135222; Claimed 10/26/2010; Published 02/15/2021. Bull. No. 5.

Claims (1)

Hybrid energy storage device for DC traction power supply system, consisting of DC energy storage devices, low-voltage bidirectional converters, converter transformer, high-voltage converters, low-voltage and high-voltage smoothing filters, reactors, current and voltage sensors, signaling and protection unit, automatic control system unit, a switching unit, characterized in that the outputs of an additional unit for transmitting measurement data on the load of adjacent substations are connected to the inputs of the unit of the automatic control system of the hybrid drive, the inputs of which are connected to the output of the additional unit of telemetry connected to the telemechanics unit of the traction power supply system.

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