Rectifying circuit, rectifying station and power supply system

Abstract

The utility model relates to a rectification circuit, a rectification station and a power supply system, the rectification circuit comprises a plurality of rectifiers in cascade connection, the plurality of rectifiers in cascade connection are used for converting alternating current into true bipolar direct current, the voltage grade of the direct current output by the rectification circuit is improved, and the rectification efficiency is improved. Therefore, the looped network voltage grade and the power supply radius of the rectification station in the power supply system are improved to meet the power supply requirement of each load device, the number of required rectification stations in the power supply system is reduced, and the equipment investment and the operation cost are reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power supply for rail transit, and in particular to a rectifier circuit, a rectifier station, and a power supply system. Background Art

[0002] As an efficient and environmentally friendly mode of public transportation, the construction and operation scale of rail transit is rapidly expanding. The power supply system of rail transit is a key infrastructure to ensure the normal operation of trains.

[0003] In the existing technology, the power supply system of rail transit generally adopts a DC unipolar power supply solution. The DC voltage level of this solution is relatively low, and the transmission and distribution of electric energy is mainly achieved through ring network lines. In addition, due to the low DC voltage level, the power supply radius is limited, which makes it difficult to meet the needs of long-distance power supply. In addition, during long-distance transmission, line losses are relatively serious, affecting the efficiency of power transmission. In order to meet the power supply needs, more rectifier stations are required, which increases equipment investment and operating costs. Utility Model Content

[0004] The purpose of the present disclosure is to provide a rectifier circuit, a rectifier station and a power supply system to improve the power supply capacity of the power supply system.

[0005] To achieve the above objectives, in a first aspect, the present disclosure provides a rectifier circuit, wherein the rectifier circuit includes a plurality of cascaded rectifiers, and the plurality of cascaded rectifiers are used to convert alternating current into true bipolar direct current.

[0006] Optionally, the rectifier circuit further includes a low-voltage AC bus, a high-voltage AC bus and a transformer, the input end of the transformer is connected to the high-voltage AC bus, the output end of the transformer is connected to the low-voltage AC bus, and the AC input ends of the multiple rectifiers are connected to the low-voltage AC bus.

[0007] Optionally, the plurality of rectifiers include a first rectifier and a second rectifier;

[0008] The AC input end of the first rectifier and the AC input end of the second rectifier are both connected to the low-voltage AC bus, the negative electrode of the output end of the first rectifier is connected to the positive electrode of the output end of the second rectifier, the first rectifier and the second rectifier are commonly grounded, and the positive electrode of the output end of the first rectifier and the negative electrode of the output end of the second rectifier are used to output a first direct current to the outside.

[0009] In a second aspect, the present disclosure further provides a rectifier station, which includes the rectifier circuit provided in the first aspect of the present disclosure, and the rectifier circuit includes a plurality of rectifiers connected in cascade.

[0010] Optionally, the rectifier circuit further includes a low-voltage AC bus, a high-voltage AC bus and a transformer, the multiple rectifiers include a first rectifier and a second rectifier, the high-voltage AC bus is connected to the low-voltage AC bus through the transformer, the AC input end of the first rectifier and the AC input end of the second rectifier are both connected to the low-voltage AC bus, the negative output end of the first rectifier is connected to the positive output end of the second rectifier, the first rectifier and the second rectifier are commonly grounded, and the positive output end of the first rectifier and the negative output end of the second rectifier are used to output the first direct current to the outside.

[0011] Optionally, the rectifier station further includes a first ring network circuit and a power distribution circuit, wherein the input end of the rectifier circuit is connected to an external AC power supply, the output end of the rectifier circuit is connected to the input end of the first ring network circuit, and the output end of the first ring network circuit is connected to the input end of the power distribution circuit;

[0012] The first ring network circuit is used to transmit the first DC power provided by the rectifier circuit to other loads, and the distribution circuit is used to adjust the voltage of the first DC power or convert the first DC power into AC power to supply power to the AC load and / or DC load corresponding to its own rectifier station.

[0013] Optionally, the first ring network circuit includes a first high-voltage DC bus, the positive output terminal of the first rectifier and the negative output terminal of the second rectifier are connected to the first high-voltage DC bus, and the first high-voltage DC bus is used to transmit the first DC power provided by the first rectifier and the second rectifier to other loads.

[0014] Optionally, the power distribution circuit includes a first DC converter, a first low-voltage DC bus, a first energy storage battery, a second DC converter, and a first inverter, wherein the first DC converter is used to convert the first DC power provided by the first high-voltage DC bus into a second DC power and transmit the second DC power to the first low-voltage DC bus; the second DC converter is used to supply power to a DC load corresponding to its own rectifier station, and the second DC power has a voltage lower than that of the first DC power;

[0015] The input end of the first DC converter is connected to the first high-voltage DC bus in the first ring network circuit, and the output end of the first DC converter is connected to the first low-voltage DC bus;

[0016] The input ends of the first energy storage battery, the second DC converter and the first inverter are all connected to the first low-voltage DC bus. The second DC converter is used to supply power to the DC load corresponding to its own rectifier station, and the first inverter is used to supply power to the AC load corresponding to its own rectifier station.

[0017] In a third aspect, the present disclosure further provides a power supply system, which includes a plurality of rectifier stations as described in the second aspect of the present disclosure.

[0018] Optionally, the power supply system includes multiple power supply partitions, each of which includes at least one rectifier station and multiple inverter stations;

[0019] In each of the power supply sections, the rectifier station and the inverter station are connected in sequence;

[0020] For any of the power supply partitions, the rectifier station is used to provide direct current power to each of the inverter stations within its own power supply partition, and / or to supply power to the corresponding loads within its own power supply partition, and the inverter station is used to convert the direct current power transmitted by the rectifier station into alternating current power and supply power to the loads corresponding to its own inverter station.

[0021] Optionally, the inverter station includes a second ring network circuit and a second power distribution circuit, and the second power distribution circuit is used to supply power to a DC load and / or an AC load corresponding to the inverter station itself;

[0022] The second power distribution circuit in any of the inverter stations is connected to the second ring network circuit;

[0023] For any of the power supply partitions, the second ring network circuit of the inverter station is connected to the second ring network circuit of the inverter station adjacent to its own inverter station, and / or is connected to the first ring network circuit of the rectifier station adjacent to its own inverter station, and / or is connected to the first inverter station in the power supply partition where its own inverter station is located, and / or is connected to the last inverter station in the power supply partition where its own inverter station is located.

[0024] Optionally, the rectifier circuit of the rectifier station includes a high-voltage AC bus, and the rectifier station further includes a first external power control switch and a second external power control switch;

[0025] For any of the rectifier stations, the high-voltage AC busbar of the rectifier station is connected to the external AC power supply through the first external power control switch, and the high-voltage AC busbar of the rectifier station is connected to the rectifier station adjacent to the rectifier station itself through the second external power control switch.

[0026] Optionally, the first ring network circuit of the rectifier station includes a first control switch, a second control switch and a third control switch, and the second ring network circuit of the inverter station includes an input control switch and an output control switch;

[0027] The first control switch and the second control switch are both used to control the on / off connection between the rectifier station and the adjacent inverter station;

[0028] The third control switch is used to control the on / off of the power supply connection between the rectifier station and the first inverter station or the last inverter station in the power supply partition corresponding to the rectifier station;

[0029] The input control switch and the output control switch are used to control the on / off of the power supply connection between the inverter station itself and an adjacent inverter station or an adjacent rectifier station.

[0030] Optionally, the second ring network circuit of the inverter station includes a second high-voltage DC bus, and the second power distribution circuit includes a third DC converter, a second low-voltage DC bus, a second energy storage battery, a fourth DC converter, and a second inverter, wherein the third DC converter and the fourth DC converter are used to adjust the voltage of the DC power;

[0031] The input end of the third DC converter is connected to the second high-voltage DC bus, and the output end of the third DC converter is connected to the second low-voltage DC bus;

[0032] The input ends of the second energy storage battery, the fourth DC converter and the second inverter are all connected to the second low-voltage DC bus. The fourth DC converter is used to supply power to the DC load corresponding to its own inverter station, and the second inverter is used to supply power to the AC load corresponding to its own inverter station.

[0033] Optionally, each of the power supply partitions is connected in sequence to form a ring network power supply loop;

[0034] In any two adjacent power supply partitions, the last station in the upstream power supply partition is connected to the first station in the downstream power supply partition. The first station and the last station in the power supply partition are rectifier stations or inverter stations. A partition control switch is set between any two adjacent power supply partitions.

[0035] Optionally, the power supply system further includes a monitoring subsystem, and the monitoring subsystem is used to monitor the fault condition of each of the rectifier station and the inverter station in the power supply system.

[0036] Through the above technical solution, multiple rectifiers are cascaded to realize true bipolar DC power supply of the rectifier circuit, which improves the ring network voltage level and power supply radius of the rectifier station in the power supply system to meet the power supply needs of various load equipment. At the same time, the required number of rectifier stations in the power supply system is reduced, reducing equipment investment and operating costs.

[0037] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0039] Figure 1 The figure is a schematic structural diagram of a rectifier circuit according to an exemplary embodiment.

[0040] Figure 2 The figure is a schematic structural diagram of a rectifier station according to an exemplary embodiment.

[0041] Figure 3 The figure is a schematic structural diagram of an inverter station according to an exemplary embodiment.

[0042] Figure 4 The figure is a schematic structural diagram of a power supply system according to an exemplary embodiment.

[0043] Figure 5 The figure is a schematic structural diagram of a power supply system according to an exemplary embodiment.

[0044] Figure 6 The figure is a structural block diagram of a power supply system according to an exemplary embodiment.

[0045] Description of Reference Numerals

[0046] Power supply system 10; rectifier station 100; rectifier circuit M0; first ring network circuit M1; first distribution circuit M2; first external power control switch QF10; second external power control switch QF20; partition control switch QN; first rectifier AD11; second rectifier AD12; low-voltage AC bus AC1; high-voltage AC bus AC0; transformer ST1; first high-voltage DC bus DC0; first DC converter DD1; first low-voltage DC bus DC1; second DC converter DD2; First inverter DA1; inverter station 200; second ring network circuit N1; second high-voltage DC bus DC2; third DC converter DD3; second low-voltage DC bus DC3; fourth DC converter DD4; second inverter DA2; second distribution circuit N2; monitoring subsystem 300; first monitoring subsystem 301; second monitoring subsystem 302; first control switch KM11, second control switch KM21 and third control switch KM12; input control switch KM1; output control switch KM2. DETAILED DESCRIPTION

[0047] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0048] In the present disclosure, unless otherwise stated, directional terms such as “upstream” generally refer to the direction of the input end, and “downstream” generally refers to the direction of the output end.

[0049] In related technical solutions, the rectifier circuit usually uses multiple rectifiers in parallel. This connection method makes the output voltage of each rectifier the same, that is, the total output voltage of multiple rectifiers is the same as the total output voltage of using a single rectifier, which cannot meet some high-voltage DC power requirements in the power supply system. In addition, due to the low voltage level of the output DC power, the transmission distance of the electric energy is short, and multiple rectifier stations are required to ensure the stable power supply of the power supply system. In addition, the polarity of the DC power output simultaneously by multiple parallel rectifiers is the same, for example, all rectifiers output positive DC power at the same time, or all rectifiers output negative DC power at the same time, which cannot meet diverse power distribution needs.

[0050] For example, if multiple rectifiers are connected in parallel and grounded, each rectifier has the same polarity relative to the common ground point. Therefore, the DC power output by the multiple parallel rectifiers can only provide a unipolar voltage range. If the rectifier circuit includes two rectifiers, and the maximum voltage of each rectifier is 100V, then the voltage range of the two rectifiers in parallel is 0 to +100V or -100V to 0. In addition, due to differences in device parameters, switching operations, and control parameters between the rectifiers in the parallel structure, the rectifier circuit may generate a circulating current, that is, the current flows between the rectifiers instead of through the load, resulting in reduced stability of the rectifier circuit.

[0051] In view of this, the present disclosure provides a rectifier circuit. Figure 1 FIG. 1 is a structural diagram of a rectifier circuit according to an exemplary embodiment. Figure 1 As shown, the rectifier circuit M0 includes a plurality of rectifiers AD connected in cascade.

[0052] In one embodiment, the rectifier circuit M0 is connected to an external alternating current (EAC). In the rectifier circuit M0, multiple cascaded rectifiers AD are used to convert AC power into DC power to provide true bipolar DC power supply. The rectifier AD can be an AC / DC (alternating current / direct current) converter.

[0053] It is worth noting that the true bipolar DC power supply of the rectifier circuit M0 is used to characterize that the DC power output by the rectifier circuit M0 includes both positive and negative poles, and the positive and negative poles are independent of each other. When any pole fails, the other pole can still supply power.

[0054] In one embodiment, the multiple rectifiers AD are preferably an even number of rectifiers AD to improve the symmetry and stability of the rectifier circuit M0. In addition, if the number of rectifiers AD is an odd number, one or more of the rectifiers AD can be used as independent unipolar power supply lines, or as a redundant structure, so that when a rectifier AD fails, support power supply can be provided through the redundant rectifier AD, thereby improving the stability and reliability of the rectifier circuit M0.

[0055] For example, the rectifier circuit M0 includes two cascaded rectifiers AD, and the maximum output voltage of each rectifier AD is 100V, one rectifier AD provides a positive voltage, and the other rectifier AD provides a negative voltage. Each rectifier AD can be independently controlled to provide true bipolar power supply, that is, the voltage range that the rectifier circuit M0 can provide is -200V to +200V, and when any rectifier AD fails, the other rectifier AD can also realize unipolar DC power supply, so that the rectifier circuit M0 can provide a wider voltage range and higher stability.

[0056] It is worth noting that the cascaded multiple rectifiers AD represent connecting the output ends of multiple rectifiers AD in series to provide true bipolar DC power supply with a higher voltage level. By connecting multiple rectifiers AD in series, the output voltage of the rectifier circuit M0 is the sum of the output voltages of multiple rectifiers AD, which improves the voltage level of the DC power output by the rectifier circuit M0, thereby improving the ring network voltage level and power supply radius of the rectifier station AD in the power supply system to meet the power supply needs of various load equipment. At the same time, the required number of rectifier stations in the power supply system is reduced, reducing equipment investment and operating costs.

[0057] Alternatively, see Figure 1 As shown, the rectifier circuit M0 also includes a low-voltage AC bus AC1, a high-voltage AC bus AC0 and a transformer ST1. The input end of the transformer ST1 is connected to the high-voltage AC bus AC0, the output end of the transformer ST1 is connected to the low-voltage AC bus AC1, and the AC input end of each rectifier is connected to the low-voltage AC bus AC1.

[0058] In one embodiment, an external AC power source is connected to a high-voltage AC bus AC0, which then steps down the high-voltage AC power to a preset voltage level through a transformer ST1, and inputs the stepped-down low-voltage AC power into a low-voltage AC bus AC1. The low-voltage AC bus AC1 then inputs the low-voltage AC power into multiple series-connected rectifiers AD to convert the low-voltage AC power into HVDC (High Voltage Direct Current), where the preset voltage level corresponds to the voltage carrying capacity of the rectifier circuit M0.

[0059] The low-voltage AC busbar AC1 can also be connected to some AC loads that can use AC power of a preset voltage level.

[0060] Optionally, the AC input end of each rectifier AD is connected to the low-voltage AC bus AC1, the DC output end of each rectifier AD is connected in series, and the DC output end of each rectifier AD is commonly grounded, that is, each rectifier AD shares a grounding point or grounding wire.

[0061] In one embodiment, the metal casings of each rectifier AD may be connected together and then grounded.

[0062] In another preferred embodiment, the common connection position of the grounding lines of the multiple rectifiers AD is set at the neutral point position between the multiple rectifiers AD to ensure the uniformity of the potential of each rectifier and improve the stability of the rectifier circuit M0.

[0063] For example, see Figure 2 As shown, the plurality of rectifiers AD include a first rectifier AD11 and a second rectifier AD12.

[0064] The AC input end of the first rectifier AD11 and the AC input end of the second rectifier AD12 are both connected to the low-voltage AC bus AC1, the negative output end of the first rectifier AD11 is connected to the positive output end of the second rectifier AD12, the first rectifier AD11 and the second rectifier AD12 are commonly grounded, and the positive output end of the first rectifier AD11 and the negative output end of the second rectifier AD12 are used to output a first direct current to the outside.

[0065] Through the above method, the current output by the first rectifier AD11 and the second rectifier AD12 is the same, but the total output voltage is increased, which improves the voltage level output by the rectifier circuit M0, and the power supply level and power supply radius of the rectifier station are also improved, thereby improving the power supply efficiency of the power supply system.

[0066] The present disclosure also provides a rectifier station, see Figure 2 As shown, the rectifier station 100 includes a first ring network circuit M1, a power distribution circuit M2, and a rectifier circuit M0. The rectifier circuit M0 includes a plurality of rectifiers AD connected in cascade.

[0067] The input end of the rectifier circuit M0 is connected to an external AC power supply, the output end of the rectifier circuit M0 is connected to the input end of the first ring network circuit M1, and the output end of the first ring network circuit M1 is connected to the input end of the power distribution circuit M2.

[0068] Among them, the first ring network circuit M1 is used to transmit the first direct current provided by the rectifier circuit M0 to other loads; the distribution circuit M2 is used to adjust the voltage of the first direct current or convert the first direct current into alternating current to supply power to the AC load and / or DC load corresponding to its own rectifier station 100. The rectifier station 100 is connected to the station adjacent to the rectifier station 100 through the first ring network circuit M1 to realize the transmission of the first direct current.

[0069] Alternatively, see Figure 2 As shown, the rectifier circuit M0 includes a low-voltage AC bus AC1, a high-voltage AC bus AC0 and a transformer ST1. The multiple rectifiers AD include a first rectifier AD11 and a second rectifier AD12. The high-voltage AC bus AC0 is connected to the low-voltage AC bus AC1 through the transformer ST1. The AC input end of the first rectifier AD11 and the AC input end of the second rectifier AD12 are both connected to the low-voltage AC bus AC1. The first rectifier AD11 and the second rectifier AD12 are commonly grounded. The negative output end of the first rectifier AD11 is connected to the positive output end of the second rectifier AD12. The positive output end of the first rectifier AD11 and the negative output end of the second rectifier AD12 are used to output a first direct current.

[0070] The positive output terminal of the first rectifier AD11 is connected to the positive line of the high-voltage DC bus DC0, and the negative output terminal of the second rectifier AD12 is connected to the negative line of the high-voltage DC bus DC0 to form a current loop through the high-voltage DC bus DC0.

[0071] Optionally, the first ring network circuit M1 includes a first high-voltage DC bus DC0, the positive output terminal of the first rectifier AD11 and the negative output terminal of the second rectifier AD12 are connected to the first high-voltage DC bus DC0, and the first high-voltage DC bus DC0 is used to transmit the first DC power provided by the first rectifier AD11 and the second rectifier AD12 to other loads.

[0072] In one embodiment, see Figure 2 As shown, the first high-voltage DC bus DC0 includes a positive line and a negative line. After the output ends of the first rectifier AD11 and the second rectifier AD12 are connected in series, the positive output end of the first rectifier AD11 is connected to the positive line of the first high-voltage DC bus DC0, and the negative output end of the second rectifier AD12 is connected to the negative line of the first high-voltage DC bus DC0.

[0073] It is worth noting that since the total output voltage of the multiple rectifiers AD connected in series is higher, that is, the voltage of the high-voltage DC bus DC0 is higher than the voltage of the high-voltage DC bus DC0 corresponding to multiple rectifiers AD in parallel or a single rectifier AD, the load usually requires low-voltage power supply. Therefore, the high-voltage DC bus DC0 cannot be mounted with low-voltage loads, such as photovoltaic devices or energy storage batteries. Then, all low-voltage loads are powered by the distribution circuit M2, which physically achieves complete isolation of the distribution circuit M2 and the ring network circuit M1, thereby improving the stability and safety of the rectifier station.

[0074] Optionally, the power distribution circuit M2 includes a first DC converter DD1, a first low-voltage DC bus DC1, a first energy storage battery, a second DC converter DD2, and a first inverter DA1, wherein the first DC converter DD1 is used to convert the first DC power provided by the first high-voltage DC bus DC0 into a second DC power, where the voltage of the second DC power is lower than that of the first DC power, and the second DC converter DD2 is used to adjust the voltage of the second DC power provided by the first low-voltage DC bus DC1 and supply power to the DC load corresponding to its own rectifier station 100, and the voltage of the DC power adjusted by the second DC converter DD2 corresponds to the DC load connected to its own inverter station.

[0075] The first DC converter DD1 and the second DC converter DD2 are both DC / DC (Direct Current / Direct Current) converters, and the first inverter DA1 is a DC / AC (Direct Current / Alternating Current) converter.

[0076] An input end of the first DC converter DD1 is connected to the first high-voltage DC bus DC0 in the first ring network circuit M1 , and an output end of the first DC converter DD1 is connected to the first low-voltage DC bus DC1 .

[0077] The input ends of the first energy storage battery, the second DC converter DD2 and the first inverter DA1 are all connected to the first low-voltage DC bus DC1. The second DC converter DD2 is used to supply power to the DC load corresponding to its own rectifier station 100, and the first inverter DA1 is used to supply power to the AC load corresponding to its own rectifier station 100.

[0078] It is worth noting that the first DC converter DD1 is used to reduce the voltage on the first high-voltage DC bus DC0 to a voltage level suitable for use by the distribution circuit M2, and the first low-voltage DC bus DC1 is used as a common connection point for the components in the distribution circuit M2 to provide a stable DC power supply. The first energy storage battery, the second DC converter DD2 and the first inverter DA1 are respectively mounted on the first low-voltage DC bus DC1. The second DC converter DD2 is used to convert the DC power output by the first low-voltage DC bus DC1 into a DC power supply of the voltage level required by the DC device to power the DC load. The first inverter DA1 is used to invert the DC power output by the first low-voltage DC bus DC1 into an AC power supply to power the AC load corresponding to its own rectifier station 100.

[0079] The first energy storage battery is used to store electric energy, so that when the external AC power supply fails, the rectifier station 100 can still be temporarily powered by the electric energy stored in the first energy storage battery.

[0080] In one embodiment, for any power supply partition, the output end of the first inverter DA1 of each rectifier station 100 in the power supply partition is connected to all AC loads in its own power supply partition, and the output end of the second DC converter DD2 is connected to all DC loads in its own power supply partition, so that when any line failure or inverter station 200 failure occurs in the power supply partition, DC support power supply can be provided through the first inverter DA1 of the rectifier station 100, and AC support power supply can be provided through the second DC converter DD2.

[0081] The present disclosure also provides a power supply system, which includes a plurality of rectifier stations described in the present disclosure.

[0082] See also Figure 3 As shown, the power supply system 10 includes multiple power supply partitions, each of which includes at least one rectifier station 100 and multiple inverter stations 200. The rectifier stations 100 in each power supply partition of the power supply system 10 are connected to an external AC power source.

[0083] In each of the power supply sections, the rectifier station 100 and the inverter station 200 are connected in sequence.

[0084] For any of the power supply partitions, the rectifier station 100 is used to provide DC power to each of the inverter stations 200 within its own power supply partition, and / or to supply power to the corresponding loads within its own power supply partition. The inverter station 200 is used to convert the DC power transmitted by the rectifier station 100 into AC power and supply power to the loads corresponding to its own inverter station 200.

[0085] Among them, each rectifier station 100 and inverter station 200 is pre-connected to the DC load and / or AC load in the power supply partition, and the rectifier station 100 is also connected to all DC loads or AC loads in the corresponding power supply partition, so that when any inverter station 200 fails or cannot supply power to the load, support power supply is provided through the rectifier station 100.

[0086] It is worth noting that the same AC load or DC load may correspond to multiple rectifier stations 100 .

[0087] In one embodiment, adjacent rectifier stations 100 and / or inverter stations 200 are connected via a ring network circuit. The rectifier station 100 can be located in the middle of the power supply partition to improve the power supply range. At the same time, the rectifier station 100 can be set at other locations within the power supply partition according to the power supply requirements of the power supply partition.

[0088] The power supply system 10 with the above structure can effectively improve power supply stability and power supply efficiency.

[0089] Alternatively, see Figure 4 As shown, the inverter station 200 includes a second ring network circuit N1 and a second power distribution circuit N2.

[0090] The second power distribution circuit N2 in any of the inverter stations 200 is connected to the second ring network circuit N1.

[0091] For any of the power supply partitions, the second ring network circuit N1 of the inverter station 200 is connected to the second ring network circuit N1 of the inverter station 200 adjacent to the inverter station, and / or is connected to the first ring network circuit M1 of the rectifier station 100 adjacent to the inverter station 200, and / or is connected to the first inverter station in the power supply partition where the inverter station 200 is located, and / or is connected to the last inverter station in the power supply partition where the inverter station 200 is located.

[0092] For example, the first power supply section includes rectifier station No. 1, inverter station No. 1, inverter station No. 2, inverter station No. 3, and inverter station No. 4. The connection method of these stations is: rectifier station No. 1 is located in the middle position of the first power supply section, the left output end of the ring network circuit of rectifier station No. 1 is connected to the right input end of the ring network circuit of inverter station No. 2, the sitting side output end of the ring network circuit of inverter station No. 2 is connected to the right input end of the ring network circuit of inverter station No. 1, the right output end of the ring network circuit of rectifier station No. 1 is connected to the left input end of the ring network circuit of inverter station No. 3, and the right output end of the ring network circuit of inverter station No. 3 is connected to the left input end of the ring network circuit of inverter station No. 4.

[0093] Alternatively, see Figure 2 and Figure 5As shown, the rectifier circuit M0 of the rectifier station 100 includes a high-voltage AC bus AC0 , and the rectifier station 100 further includes a first external power control switch QF10 and a second external power control switch QF20 .

[0094] For any of the rectifier stations 100, the high-voltage AC bus AC0 of the rectifier station 100 is connected to the external AC power source through the first external power control switch QF10, and the high-voltage AC bus AC0 of the rectifier station 100 is connected to the rectifier station 100 adjacent to the rectifier station 100 through the second external power control switch QF20.

[0095] In one embodiment, each power supply section includes a rectifier station 100, and the high-voltage AC busbars AC0 of the rectifier stations 100 in adjacent power supply sections are connected by cables. The second external power control switch QF200 is used to control the on and off connection between the rectifier stations 100 in adjacent power supply sections. When the external AC voltage connected to any rectifier station 100 is lost, the second external power control switch QF200 corresponding to its own rectifier station 100 can be turned on to enable the rectifier station 100 in the adjacent power supply section to provide support power to the rectifier station 100, thereby improving the stability of the power supply system.

[0096] In another embodiment, each power supply section includes multiple rectifier stations 100, and the high-voltage AC busbar AC0 of each rectifier station 100 in the power supply point section is connected by a cable, and at least one second external power control switch QF200 is provided between any two connected rectifier stations 100, so that multiple rectifier stations in the same power supply section can support each other in power supply.

[0097] Optionally, the first ring network circuit M1 of the rectifier station includes a first control switch KM11, a second control switch KM21 and a third control switch KM12, and the second ring network circuit N1 of the inverter station includes an input control switch KM1 and an output control switch KM2.

[0098] The first control switch KM11 and the second control switch KM21 are both used to control the on / off connection between the rectifier station 100 and the adjacent inverter station 200 .

[0099] In one embodiment, see Figures 2 to 4 As shown, when a fault occurs in the rectifier station 100, the first control switch KM11 and the second control switch KM21 of the rectifier AD can be disconnected to disconnect the connection between the rectifier AD and its adjacent inverter station 200, thereby preventing the fault of the rectifier station 100 from spreading to the inverter station 200.

[0100] The third control switch KM12 is used to control the on / off of the power supply connection between the rectifier station 100 and the first inverter station or the last inverter station in the power supply section corresponding to the rectifier station 100 .

[0101] In one embodiment, for each power supply partition, the first ring network circuit M1 of the rectifier station 100 is connected to the second ring network circuit N1 of the first inverter station or the second ring network circuit N1 of the last inverter station in the power supply partition. For example, the first inverter station can be the inverter station 200 located on the leftmost side of the power supply partition, and the last inverter station can be the inverter station 200 located on the rightmost side of the power supply partition. Through the third control switch KM12, when any line fails, the rectifier station can support power supply.

[0102] For example, power supply section No. 1 includes inverter station No. 1, inverter station No. 2, rectifier station, inverter station No. 3, and inverter station No. 4 connected in sequence, among which inverter station No. 1 is the first inverter station and inverter station No. 4 is the last inverter station. When there is no fault in power supply section No. 1, the third control switch KM12 of power supply section No. 1 is disconnected, and the power supply line is from the rectifier station to inverter station No. 2, from inverter station No. 2 to inverter station No. 1, and from the rectifier station to inverter station No. 3, and from inverter station No. 3 to inverter station No. 4. In the event of a fault in the connecting line between the rectifier station and inverter station No. 2, both inverter station No. 1 and inverter station No. 2 are powered off, and the third control switch KM12 can be closed to achieve support power supply, that is, the power supply line becomes from the rectifier station to inverter station No. 1, and from inverter station No. 1 to inverter station No. 2.

[0103] The input control switch KM1 and the output control switch KM2 are used to control the on / off of the power supply connection between the inverter station itself and an adjacent inverter station or an adjacent rectifier station.

[0104] In one embodiment, see Figure 4 As shown, when a fault occurs in the rectifier station 100 or the inverter station 200, the input control switch and the output control switch of the faulty station can be disconnected to cut off the faulty station from the power supply system. When a fault occurs in the inter-station line between the rectifier station 100 and / or the inverter station 200, the control switch of the previous station on the faulty line and the control switch of the next station on the faulty line can be disconnected to cut off the faulty line from the power supply system.

[0105] For example, the output end of rectifier station No. 1 is connected to the input end of inverter station No. 1, and the output end of inverter station No. 1 is connected to the input end of inverter station No. 2. In the connection line between rectifier station No. 1 and inverter station No. 1, the control switch at the rectifier station No. 1 end is the first control switch KM11, and the control switch at the inverter station No. 1 end is the input control switch KM1. In the connection line between inverter station No. 1 and inverter station No. 2, the control switch at the inverter station No. 1 end is the output control switch KM2, and the control switch at the inverter station No. 2 end is the input control switch KM3. The fault area in the power supply system 10 is cut off through the processing methods corresponding to the following situations.

[0106] Case 1: If the fault area is the inverter station 200, the input and output control switches of the faulty inverter station 200 are disconnected. For example, when the inverter station No. 1 fails, the input control switch KM1 of the inverter station No. 1 and the output control switch KM2 of the inverter station No. 1 are disconnected to cut off the faulty inverter station No. 1 from the power supply system 10.

[0107] After the No. 1 reverse flow station is cut off, the distribution circuit M2 of an adjacent rectifier station 100 on the left and right sides of the No. 1 reverse flow station is responsible for providing support power to the No. 1 reverse flow station. If the power supply partition where the No. 1 inverter station is located is the first power supply partition or the last power supply partition, the distribution circuit M2 of the rectifier station 100 in the power supply partition where the No. 1 inverter station is located is responsible for providing support power to the No. 1 reverse flow station.

[0108] Case 2: If the fault area is an inter-station line, disconnect the output control switch of the upstream station of the fault line, and disconnect the input control switch of the downstream station of the fault line. For example, when a fault occurs on the line between inverter station No. 1 and inverter station No. 2, disconnect the output control switch KM2 of inverter station No. 1 and the input control switch KM3 of inverter station No. 2 to cut off the fault line.

[0109] After the fault line between inverter station No. 1 and inverter station No. 2 is cut off, within the power supply area where inverter station No. 1 and inverter station No. 2 are located, the rectifier station 100 is also connected to the first inverter station or the last inverter station in the power supply area. By opening the connection switch between the rectifier station 100 and the first inverter station and / or the last inverter station, the power supply in the power supply interval can be quickly restored. For example, inverter station No. 2 is the first inverter station in the power supply area, and the control switch of the cable between rectifier station No. 1 and inverter station No. 2 is the third control switch KM12. When the connection line between rectifier station No. 1 and inverter station No. 1 is disconnected, the third control switch KM12 can be turned on to realize the current from rectifier station No. 1 to inverter station No. 2 first, and then from inverter station No. 2 to inverter station No. 1, and each load in the power supply area still maintains normal power supply.

[0110] Case 3: If the fault area is the rectifier station 100 , the first control switch KM11 and the second control switch KM21 of the faulty rectifier station 100 are disconnected to cut off the faulty rectifier station 100 .

[0111] After the faulty rectifier station 100 is cut off, for example, after rectifier station No. 1 is cut off, support power supply can be provided by the rectifier stations in the power supply partitions on both sides of the power supply partition where rectifier station No. 1 is located, or support power supply can be provided by the distribution circuit M3 of other rectifier stations in the power supply partition where rectifier station No. 1 is located.

[0112] Alternatively, see Figure 4 As shown, the second ring network circuit N1 of the inverter station includes a second high-voltage DC bus DC2, and the second distribution circuit N2 includes a third DC converter DD3, a second low-voltage DC bus DC3, a second energy storage battery, a fourth DC converter DD4 and a second inverter DA2.

[0113] An input end of the third DC converter DD3 is connected to the second high-voltage DC bus DC2 , and an output end of the third DC converter DD3 is connected to the second low-voltage DC bus DC3 .

[0114] The input ends of the second energy storage battery, the fourth DC converter DD4 and the second inverter DA2 are all connected to the second low-voltage DC bus DC3. The fourth DC converter DD4 is used to adjust the voltage of the low-voltage DC power provided by the second low-voltage DC bus DC3 to supply power to the DC load corresponding to its own inverter station 200. The second inverter DA2 is used to convert the low-voltage DC power provided by the second low-voltage DC bus DC3 into AC power to supply power to the AC load corresponding to its own inverter station 200.

[0115] Each inverter station 200 is pre-assigned an AC load and a DC load, and the same AC load or DC load can correspond to multiple inverter stations 200 .

[0116] It is worth noting that the adjacent inverter stations 200 and rectifier stations 100 are connected via the second ring network circuit N1 and the first ring network circuit M1 , and the adjacent inverter stations 200 are connected via their respective second ring network circuits N1 .

[0117] In one embodiment, after receiving high-voltage direct current (HVDC) power input from an upstream station via a second ring network circuit N1, the inverter station 200 supplies DC power and / or AC power to the inverter station 200 via a second distribution circuit N2 connected to the second ring network circuit N1. A third DC converter DD3 of the second distribution circuit N2 is mounted on a second high-voltage DC bus DC2 of the second ring network circuit N1. The third DC converter DD3 is configured to convert the high-voltage DC power in the second high-voltage DC bus DC2 into low-voltage DC power at a voltage level suitable for the second distribution circuit N2. The third DC converter DD3 then inputs the low-voltage DC power into a second low-voltage DC bus DC3 of the second distribution circuit N2. A second energy storage battery, a fourth DC converter DD4, and a second inverter DA2 are all mounted on the second low-voltage DC bus DC3. The second energy storage battery is configured to store electrical energy and, in the event that no electrical energy is received at the input end of the inverter station 200 and / or the second ring network circuit N1 fails, the electrical energy stored in the second energy storage battery is used to temporarily power the loads corresponding to the inverter station 200.

[0118] Alternatively, see Figure 3 As shown, each of the power supply partitions is connected in sequence to form a ring network power supply loop.

[0119] In any two adjacent power supply partitions, the last station in the upstream power supply partition is connected to the first station in the downstream power supply partition. The first station and the last station in the power supply partition are rectifier stations or inverter stations. A partition control switch QN is provided between any two adjacent power supply partitions. The partition control switch QN is used to control the on and off of the connection between two identical power supply partitions.

[0120] In one embodiment, in a ring network power supply loop formed by multiple power supply partitions, the one on the relatively left side of any two adjacent connected power supply partitions is the upstream power supply partition, and the one on the relatively right side is the downstream power supply partition. The leftmost station in each power supply partition is the first station, and the rightmost station is the last station.

[0121] Among them, through the partition control switch QN, the connection and isolation between the power supply partitions can be achieved according to the power supply demand and power supply circuit structure in the power supply system 10.

[0122] Alternatively, see Figure 6 As shown, the power supply system 10 further includes a monitoring subsystem 300 , and the monitoring subsystem 300 is used to monitor the fault conditions of each of the rectifier station 100 and the inverter station 200 in the power supply system 10 .

[0123] In one embodiment, the monitoring subsystem 300 includes a first monitoring subsystem 301 and a second monitoring subsystem 302. The second monitoring subsystem 302 is used to monitor the fault condition of the inverter station 200 in the power supply system 10. The second monitoring subsystem 302 determines the fault condition of the inverter station 200 by collecting status information of the inverter station 200, and when a fault occurs in the inverter station 200, disconnects the connection between the inverter station 200 and its adjacent inverter station 200 and / or adjacent rectifier station 100 to avoid the spread of the fault, and uploads the fault condition of the inverter station 200 to the first monitoring subsystem 301.

[0124] The first monitoring subsystem 301 is used to monitor the operation and fault conditions of the rectifier station 100 in the power supply system 10, and according to the fault condition of the rectifier station 100 and the fault condition of the inverter station 200 uploaded by the second monitoring subsystem 302, control the connection between the rectifier station 100 and the inverter station 200 connected thereto, and / or disconnect the connection between the power supply partition with the fault and the adjacent power supply partition.

[0125] In one embodiment, when a fault occurs at any site and / or a cable between sites in the power supply system 10 , the monitoring subsystem 300 collects power flow directions on the left and right sides of the fault site to understand the flow path and load distribution of electrical energy in the power supply system 10 .

[0126] When a fault occurs, the power supply system 10 will detect an abnormality such as overcurrent, voltage drop or other fault signals through the monitoring subsystem 300. The monitoring subsystem 300 can then determine the fault interval by analyzing the flow direction on both sides of the fault point. For example, if the flow directions on both sides of the fault point are opposite, it means that the fault occurs between the two monitoring points. After determining the fault interval, the monitoring subsystem 300 will cut off the connection between the fault interval and the station or power supply interval connected to it in the power supply system 10 to prevent the fault from spreading.

[0127] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0128] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0129] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A rectifier circuit, characterized in that: The rectifier circuit includes a plurality of rectifiers connected in cascade; The cascaded multiple rectifiers are used to convert AC power into true bipolar DC power.

2. The rectifier circuit according to claim 1, characterized in that: The rectifier circuit also includes a low-voltage AC bus, a high-voltage AC bus and a transformer, the input end of the transformer is connected to the high-voltage AC bus, the output end of the transformer is connected to the low-voltage AC bus, and the AC input ends of the multiple rectifiers are connected to the low-voltage AC bus.

3. The rectifier circuit according to claim 2, characterized in that: The plurality of rectifiers include a first rectifier and a second rectifier; The AC input end of the first rectifier and the AC input end of the second rectifier are both connected to the low-voltage AC bus, the negative electrode of the output end of the first rectifier is connected to the positive electrode of the output end of the second rectifier, the first rectifier and the second rectifier are commonly grounded, and the positive electrode of the output end of the first rectifier and the negative electrode of the output end of the second rectifier are used to output a first direct current to the outside.

4. A rectifier station, characterized in that: The rectification station comprises the rectification circuit according to any one of claims 1 to 3, wherein the rectification circuit comprises a plurality of rectifiers connected in cascade.

5. The rectifier station according to claim 4, characterized in that: The rectifier circuit includes a low-voltage AC bus, a high-voltage AC bus, and a transformer. The multiple rectifiers include a first rectifier and a second rectifier. The high-voltage AC bus is connected to the low-voltage AC bus through the transformer. The AC input end of the first rectifier and the AC input end of the second rectifier are both connected to the low-voltage AC bus. The first rectifier and the second rectifier are commonly grounded. The negative output end of the first rectifier is connected to the positive output end of the second rectifier. The positive output end of the first rectifier and the negative output end of the second rectifier are used to output a first direct current to the outside.

6. The rectifier station according to claim 5, characterized in that: The rectifier station further includes a first ring network circuit and a power distribution circuit, wherein the input end of the rectifier circuit is connected to an external AC power supply, the output end of the rectifier circuit is connected to the input end of the first ring network circuit, and the output end of the first ring network circuit is connected to the input end of the power distribution circuit; The first ring network circuit is used to transmit the first DC power provided by the rectifier circuit to other loads, and the distribution circuit is used to adjust the voltage of the first DC power or convert the first DC power into AC power to supply power to the AC load and / or DC load corresponding to its own rectifier station.

7. The rectifier station according to claim 6, characterized in that: The first ring network circuit includes a first high-voltage DC bus, the positive output terminal of the first rectifier and the negative output terminal of the second rectifier are connected to the first high-voltage DC bus, and the first high-voltage DC bus is used to transmit the first DC power provided by the first rectifier and the second rectifier to other loads.

8. The rectifier station according to claim 7, characterized in that: The power distribution circuit includes a first DC converter, a first low-voltage DC bus, a first energy storage battery, a second DC converter, and a first inverter, wherein the first DC converter is used to convert the first DC power provided by the first high-voltage DC bus into a second DC power and transmit the second DC power to the first low-voltage DC bus; the second DC converter is used to supply power to a DC load corresponding to its own rectifier station, and the second DC power has a lower voltage than the first DC power; The input end of the first DC converter is connected to the first high-voltage DC bus in the first ring network circuit, and the output end of the first DC converter is connected to the first low-voltage DC bus; The input ends of the first energy storage battery, the second DC converter and the first inverter are all connected to the first low-voltage DC bus. The second DC converter is used to supply power to the DC load corresponding to its own rectifier station, and the first inverter is used to supply power to the AC load corresponding to its own rectifier station.

9. A power supply system, characterized in that: The power supply system comprises a plurality of rectifier stations according to any one of claims 4 to 8.

10. The power supply system according to claim 9, characterized in that: The power supply system includes a plurality of power supply partitions, each of which includes at least one rectifier station and a plurality of inverter stations; In each of the power supply sections, the rectifier station and the inverter station are connected in sequence; For any of the power supply partitions, the rectifier station is used to provide direct current power to each of the inverter stations within its own power supply partition, and / or to supply power to the corresponding loads within its own power supply partition, and the inverter station is used to convert the direct current power transmitted by the rectifier station into alternating current power and supply power to the loads corresponding to its own inverter station.

11. The power supply system according to claim 10, characterized in that: The inverter station includes a second ring network circuit and a second power distribution circuit, wherein the second power distribution circuit is used to supply power to the DC load and / or AC load corresponding to the inverter station itself; The second power distribution circuit in any of the inverter stations is connected to the second ring network circuit; For any of the power supply partitions, the second ring network circuit of the inverter station is connected to the second ring network circuit of the inverter station adjacent to its own inverter station, and / or is connected to the first ring network circuit of the rectifier station adjacent to its own inverter station, and / or is connected to the first inverter station in the power supply partition where its own inverter station is located, and / or is connected to the last inverter station in the power supply partition where its own inverter station is located.

12. The power supply system according to claim 9, characterized in that: The rectifier circuit of the rectifier station includes a high-voltage AC bus, and the rectifier station also includes a first external power control switch and a second external power control switch; For any of the rectifier stations, the high-voltage AC busbar of the rectifier station is connected to the external AC power supply through the first external power control switch, and the high-voltage AC busbar of the rectifier station is connected to the rectifier station adjacent to the rectifier station itself through the second external power control switch.

13. The power supply system according to claim 11, wherein: The first ring network circuit of the rectifier station includes a first control switch, a second control switch and a third control switch, and the second ring network circuit of the inverter station includes an input control switch and an output control switch; The first control switch and the second control switch are both used to control the on / off connection between the rectifier station and the adjacent inverter station; The third control switch is used to control the on / off of the power supply connection between the rectifier station and the first inverter station or the last inverter station in the power supply partition corresponding to the rectifier station; The input control switch and the output control switch are used to control the on / off of the power supply connection between the inverter station itself and an adjacent inverter station or an adjacent rectifier station.

14. The power supply system according to claim 11, wherein: The second ring network circuit of the inverter station includes a second high-voltage DC bus, and the second power distribution circuit includes a third DC converter, a second low-voltage DC bus, a second energy storage battery, a fourth DC converter and a second inverter, wherein the third DC converter and the fourth DC converter are used to adjust the voltage of the DC power; The input end of the third DC converter is connected to the second high-voltage DC bus, and the output end of the third DC converter is connected to the second low-voltage DC bus; The input ends of the second energy storage battery, the fourth DC converter and the second inverter are all connected to the second low-voltage DC bus. The fourth DC converter is used to supply power to the DC load corresponding to its own inverter station, and the second inverter is used to supply power to the AC load corresponding to its own inverter station.

15. The power supply system according to claim 10, wherein: Each of the power supply partitions is connected in sequence to form a ring network power supply loop; In any two adjacent power supply partitions, the last station in the upstream power supply partition is connected to the first station in the downstream power supply partition. The first station and the last station in the power supply partition are rectifier stations or inverter stations, and a partition control switch is provided between any two adjacent power supply partitions.

16. The power supply system according to claim 10, wherein: The power supply system further includes a monitoring subsystem, which is used to monitor the fault conditions of each of the rectifier station and the inverter station in the power supply system.

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