Towing power supply integrated energy system

Abstract

The utility model discloses a kind of traction power supply comprehensive energy systems, including railway energy router, low-voltage direct-current bus, power source, direct-current converter, energy storage and controller;The direct-current port of the railway energy router is connected low-voltage direct-current bus, a phase port of alternating side is connected railway traction power supply a phase, b phase port of alternating side is connected railway traction power supply b phase;Power source is connected low-voltage direct-current bus after controllable direct-current electricity output by direct-current converter;Energy storage is directly connected low-voltage direct-current bus;The signal end of the controller is connected with the signal end of railway energy router, power source, direct-current converter, energy storage respectively.The present application effectively solves the problem of integrating renewable new energy and not with DC-DC energy storage into railway energy router low-voltage direct-current bus.

Description

Technical Field

[0001] This utility model belongs to the field of new energy technology for traction power supply in electrified railways, and in particular relates to a comprehensive energy system for traction power supply. Background Technology

[0002] By the end of 2024, the total operating mileage of railways in China had reached 162,000 kilometers, of which more than 120,000 kilometers were electrified, with annual energy consumption exceeding 100 billion kWh. For a long time, electrified railways have been highly dependent on the public power grid, which relies mainly on fossil fuels, resulting in persistently high carbon emissions. The integration of green renewable energy with electrified railways, and technologies such as energy storage to recover regenerative braking energy from trains, have become the development trend of electrified railway technology.

[0003] Existing electrified railway traction power supply systems employ railway energy routers (RERs) to integrate new energy sources and recover regenerative braking energy from trains, while simultaneously addressing reactive power and negative sequence issues in the traction power supply system. Current research indicates that energy storage requires connection to a DC bus with large-capacity inductors and capacitors via a DC-DC converter, and relies on the energy storage DC-DC converter to control the DC bus voltage. However, the energy storage DC-DC converter and the large-capacity inductors and capacitors introduce both device cost issues and reduced system energy efficiency. Utility Model Content

[0004] In order to overcome the shortcomings of existing technologies, the purpose of this utility model is to propose a traction power supply integrated energy system that can effectively solve the technical problems of integrating renewable new energy sources such as photovoltaic and wind power, as well as low-voltage DC bus accessing railway energy routers without DC-DC energy storage.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a traction power supply integrated energy system, including: a railway energy router (RER), a low-voltage DC bus (LVDB), a generator (PGR), a DC converter (DCC), an energy storage system (ESS), and a controller (CC).

[0006] The railway energy router (RER) includes a DC port, an AC a-phase port, and an AC b-phase port. The DC port is connected to the low-voltage DC bus (LVDB), the AC a-phase port is connected to the railway traction power supply a-phase, and the AC b-phase port is connected to the railway traction power supply b-phase.

[0007] The power source PGR outputs controllable DC power through the DC converter DCC and then connects to the low-voltage DC bus LVDB.

[0008] The energy storage ESS is directly connected to the low-voltage DC bus LVDB;

[0009] The signal ports of the controller CC are connected to the signal terminals of the railway energy router RER, the power source PGR, the DC converter DCC, and the energy storage ESS, respectively.

[0010] Furthermore, the railway energy router (RER) adopts a back-to-back structure and includes: single-phase inverters DACa and DACb. The AC sides of the single-phase inverters DACa and DACb are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation respectively via step-up transformers. The DC sides of the single-phase inverters DACa and DACb are connected in parallel and then connected to the low-voltage DC bus LVDB.

[0011] Furthermore, the railway energy router RER adopts a cross-phase structure, including: a cross-phase single-phase inverter IBI, a traction power supply a-phase reactive power compensation device RPOa, and a traction power supply b-phase reactive power compensation device RPOb. The two AC ports of the cross-phase single-phase inverter IBI are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation via a step-up transformer. The DC side of the cross-phase single-phase inverter IBI is connected to the low-voltage DC bus LVDB.

[0012] Furthermore, the railway energy router (RER) adopts a star-shaped structure and includes: a cross-phase single-phase inverter (IBI), a static var generator (SVGa), and a static var generator (SVGb). The two AC ports of the cross-phase single-phase inverter IBI are connected to the a-phase circuit and b-phase circuit of the traction substation or sectioning station via a step-up transformer. The AC sides of the static var generators SVGa and SVGb are respectively connected to the a-phase circuit and b-phase circuit of the traction substation or sectioning station. The DC sides of the cross-phase single-phase inverter IBI, SVGa, and SVGb are all connected in parallel to the low-voltage DC bus (LVDB).

[0013] Furthermore, the power source PGR includes at least one of photovoltaic, wind power, hydropower, fuel cell, and nuclear power; the power source PGR converts DC or AC power into DC output that is compatible with the low-voltage DC bus LVDB voltage via a DC converter.

[0014] Furthermore, the energy storage ESS includes at least one of lithium titanate batteries, lithium iron phosphate batteries, solid-state batteries, semi-solid-state batteries, and sodium-ion batteries; the energy storage ESS is directly connected to the low-voltage DC bus LVDB, and its operating voltage range is adapted to the allowable fluctuation range of the low-voltage DC bus LVDB.

[0015] The beneficial effects of adopting this technical solution are:

[0016] This utility model proposes a railway traction power supply integrated energy system with a railway energy router using a low-voltage DC bus. The railway energy router is designed to eliminate the low-voltage DC bus with large-capacity inductors and capacitors. The energy storage is designed to withstand second-harmonic ripple impacts and eliminates the DC-DC converter. This avoids the purchase cost and operating losses of low-voltage DC bus inductors and capacitors and energy storage DC-DC converters in existing research, thereby reducing system cost and improving system energy efficiency. Attached Figure Description

[0017] Figure 1 This is a topological diagram of the integrated energy system structure for railway traction power supply according to the present invention;

[0018] Figure 2 This is a system structure topology diagram of the first embodiment of the present invention;

[0019] Figure 3 This is a system structure topology diagram of the second embodiment of the present invention;

[0020] Figure 4 This is a system structure topology diagram of the third embodiment of the present invention. Detailed Implementation

[0021] To make the purpose, technical solution and advantages of this utility model clearer, the present utility model will be further described below with reference to the accompanying drawings.

[0022] In this embodiment, see Figure 1 As shown, a traction power supply integrated energy system includes: a railway energy router (RER), a low-voltage DC bus (LVDB), a generator (PGR), a DC converter (DCC), an energy storage system (ESS), and a controller (CC).

[0023] The railway energy router (RER) includes a DC port, an AC a-phase port, and an AC b-phase port. The DC port is connected to the low-voltage DC bus (LVDB), the AC a-phase port is connected to the railway traction power supply a-phase, and the AC b-phase port is connected to the railway traction power supply b-phase.

[0024] The power source PGR outputs controllable DC power through the DC converter DCC and then connects to the low-voltage DC bus LVDB.

[0025] The energy storage ESS is directly connected to the low-voltage DC bus LVDB;

[0026] The signal ports of the controller CC are connected to the signal terminals of the railway energy router RER, the power source PGR, the DC converter DCC, and the energy storage ESS, respectively.

[0027] As an optimization scheme 1 of the above embodiments, such as Figure 2As shown, the railway energy router (RER) adopts a back-to-back structure and includes: single-phase inverters DACa and DACb. The AC sides of single-phase inverters DACa and DACb are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation respectively via step-up transformers. The DC sides of single-phase inverters DACa and DACb are connected in parallel and then connected to the low-voltage DC bus LVDB.

[0028] As an optimization scheme 2 of the above embodiments, such as Figure 3 As shown, the railway energy router RER adopts a cross-phase structure and includes: a cross-phase single-phase inverter IBI, a traction power supply a-phase reactive power compensation device RPOa, and a traction power supply b-phase reactive power compensation device RPOb. The two AC ports of the cross-phase single-phase inverter IBI are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation via a step-up transformer. The DC side of the cross-phase single-phase inverter IBI is connected to the low-voltage DC bus LVDB.

[0029] As an optimization scheme 3 of the above embodiments, such as Figure 4 As shown, the railway energy router (RER) adopts a star-shaped structure and includes: a cross-phase single-phase inverter (IBI), a static var generator (SVGa), and a static var generator (SVGb). The two AC ports of the cross-phase single-phase inverter IBI are connected to the a-phase circuit and the b-phase circuit of the traction substation or sectioning station via a step-up transformer. The AC sides of the static var generators SVGa and SVGb are respectively connected to the a-phase circuit and the b-phase circuit of the traction substation or sectioning station. The DC sides of the cross-phase single-phase inverter IBI, the static var generator SVGa, and the static var generator SVGb are all connected in parallel to the low-voltage DC bus (LVDB).

[0030] The power source PGR includes, but is not limited to, one of photovoltaic, wind power, hydropower, fuel cell, and nuclear power; the power source PGR converts DC or AC power into DC output that is compatible with the low-voltage DC bus LVDB voltage via a DC converter.

[0031] The energy storage ESS includes, but is not limited to, one of lithium titanate batteries, lithium iron phosphate batteries, solid-state batteries, semi-solid-state batteries, and sodium-ion batteries; the energy storage ESS is directly connected to the low-voltage DC bus LVDB, and its operating voltage range is adapted to the allowable fluctuation range of the low-voltage DC bus LVDB.

[0032] To better understand this utility model, the working principle of this utility model will be described in detail below:

[0033] The railway energy router (RER) uses a low-voltage DC bus (LVDB) without large-capacity inductors and capacitors (DC bus voltage <1000V, which can be appropriately relaxed to a peak voltage of 1500V). The energy storage ESS does not have a DC-DC converter directly connected to the low-voltage DC bus (LVDB). The generator (PGR) converts DC or AC power into voltage-adapted DC output via a DC converter (DCC) and then connects to the low-voltage DC bus (LVDB). The railway energy router (RER) contains a DC port, an AC-side a-phase port, and an AC-side b-phase port. Its DC port is connected to the low-voltage DC bus. The low-voltage DC bus (LVDB) has its AC-side a-phase port connected to the railway traction power supply a-phase, and its AC-side b-phase port connected to the railway traction power supply b-phase. All three ports can be adjusted bidirectionally for power flow as needed. The energy storage ESS actively clamps the voltage of the low-voltage DC bus (LVDB). The power generation PGR adopts constant current closed-loop control. The railway energy router adopts constant current closed-loop control when the external public grid is supplying power normally, and adopts grid-type constant voltage and constant frequency control when the external public grid fails, so as to realize the consumption of new energy, the recovery and utilization of braking energy, the optimization of power quality, and the guarantee of emergency power supply.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A traction power supply integrated energy system, characterized in that, include: Railway energy router (RER), low-voltage DC bus (LVDB), power generator (PGR), DC converter (DCC), energy storage system (ESS), and controller (CC); The railway energy router (RER) includes a DC port, an AC a-phase port, and an AC b-phase port. The DC port is connected to the low-voltage DC bus (LVDB), the AC a-phase port is connected to the railway traction power supply a-phase, and the AC b-phase port is connected to the railway traction power supply b-phase. The power source PGR outputs controllable DC power through the DC converter DCC and then connects to the low-voltage DC bus LVDB. The energy storage ESS is directly connected to the low-voltage DC bus LVDB; The signal ports of the controller CC are connected to the signal terminals of the railway energy router RER, the power source PGR, the DC converter DCC, and the energy storage ESS, respectively.

2. The traction power supply integrated energy system according to claim 1, characterized in that, The railway energy router (RER) adopts a back-to-back structure and includes: single-phase inverters DACa and DACb. The AC sides of the single-phase inverters DACa and DACb are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation respectively via step-up transformers. The DC sides of the single-phase inverters DACa and DACb are connected in parallel and then connected to the low-voltage DC bus LVDB.

3. The traction power supply integrated energy system according to claim 1, characterized in that, The railway energy router (RER) adopts a cross-phase structure and includes: a cross-phase single-phase inverter (IBI), a traction power supply a-phase reactive power compensation device (RPOa), and a traction power supply b-phase reactive power compensation device (RPOb). The two AC ports of the cross-phase single-phase inverter (IBI) are connected to the a-phase circuit and b-phase circuit of the traction substation or section substation via a step-up transformer. The DC side of the cross-phase single-phase inverter (IBI) is connected to the low-voltage DC bus (LVDB).

4. The traction power supply integrated energy system according to claim 1, characterized in that, The railway energy router (RER) adopts a star-shaped structure and includes: a cross-phase single-phase inverter (IBI), a static var generator (SVGa), and a static var generator (SVGb). The two AC ports of the cross-phase single-phase inverter IBI are connected to the a-phase circuit and the b-phase circuit of the traction substation or sectioning station via a step-up transformer. The AC sides of the static var generators SVGa and SVGb are respectively connected to the a-phase circuit and the b-phase circuit of the traction substation or sectioning station. The DC sides of the cross-phase single-phase inverter IBI, the static var generator SVGa, and the static var generator SVGb are all connected in parallel to the low-voltage DC bus (LVDB).

5. A traction power supply integrated energy system according to any one of claims 1-4, characterized in that, The power source PGR includes at least one of photovoltaic, wind power, hydropower, fuel cell, and nuclear power; the power source PGR converts DC or AC power into DC output that is compatible with the low voltage DC bus LVDB voltage via DC converter.

6. A traction power supply integrated energy system according to any one of claims 1-4, characterized in that, The energy storage ESS includes at least one of lithium titanate battery, lithium iron phosphate battery, solid-state battery, semi-solid-state battery, and sodium-ion battery; the energy storage ESS is directly connected to the low-voltage DC bus LVDB, and its operating voltage range is adapted to the allowable fluctuation range of the low-voltage DC bus LVDB.

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