Direct current elevator system and direct current elevator

Abstract

The invention relates to the technical field of elevator energy-saving control, and particularly discloses a direct-current elevator system and a direct-current elevator. The system comprises a direct-current input power supply, a direct-current frequency converter and a direct-current traction machine; the DC input power supply is used for providing DC input for the DC frequency converter. The direct current frequency converter is connected with the direct current traction machine and used for driving the direct current traction machine; the first semiconductor step-down module is connected with the direct-current input power supply and is used for executing step-down operation and outputting first direct-current voltage; the plurality of first direct current components are connected with the first semiconductor step-down module, and each first direct current component operates based on the first direct current voltage; the second semiconductor step-down module is connected with the first semiconductor step-down module and is used for executing step-down operation and outputting second direct-current voltage; the plurality of second direct current components are connected with the second semiconductor step-down module, and each second direct current component operates based on the second direct current voltage; the first DC voltage is lower than the DC input voltage, and the second DC voltage is lower than the first DC voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator energy-saving control, and in particular to a direct current elevator system and a direct current elevator. Background Art

[0002] In the process of modern high-rise buildings and urbanization, the energy consumption of elevators as vertical transportation tools has received increasing attention. Traditional AC elevator systems are composed of AC equipment or components. During use, on the one hand, the AC elevator system consumes AC power; on the other hand, the DC regenerative power generated during the operation of the elevator cannot be directly used, so it is often directly consumed through consumption resistors, or converted into AC power through conversion equipment and then sent to the power grid.

[0003] However, in actual application, neither the electric energy directly consumed nor the electric energy sent to the power grid can be reused by the elevator. Therefore, it has certain limitations in energy consumption and cannot meet the needs of higher energy efficiency.

[0004] With the continuous development of new energy technologies in recent years, DC power supply has been increasingly used in our lives. Combined with the high efficiency and energy saving characteristics of DC elevator systems, it has gradually attracted attention. DC elevator systems usually use variable frequency speed regulation technology and energy feedback technology. These technologies can dynamically adjust the power supply frequency and voltage of the motor according to the actual operation needs of the elevator, thereby achieving energy saving. However, there is currently no DC elevator system, so it cannot meet market demand. Summary of the invention

[0005] In order to overcome the above-mentioned technical problems existing in the prior art, the embodiments of the present invention provide a DC elevator system and a DC elevator, which allow the elevator to operate in the most economical way by improving the traditional elevator to DC, thereby effectively reducing the elevator operating cost and meeting user needs.

[0006] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a DC elevator system, which includes: a DC input power supply, a DC inverter and a DC traction machine; the DC input power supply is connected to the DC inverter to provide a DC input for the DC inverter; the DC inverter is connected to the DC traction machine to drive the DC traction machine; a first semiconductor buck module is connected to the DC input power supply to perform a buck operation and output a first DC voltage; a plurality of first DC components are connected to the first semiconductor buck module, each of which operates based on the first DC voltage; a second semiconductor buck module is connected to the first semiconductor buck module to perform a buck operation and output a second DC voltage; a plurality of second DC components are connected to the second semiconductor buck module, each of which operates based on the second DC voltage; the first DC voltage is lower than the voltage of the DC input, and the second DC voltage is lower than the first DC voltage.

[0007] Preferably, the DC elevator system further comprises a regenerative energy device connected to the DC traction machine for generating regenerative energy; the regenerative energy device is further connected to an energy storage device, and the energy storage device is connected to the DC frequency converter.

[0008] Preferably, the first DC component includes a main control module, which is used to: determine whether the driving signal of the DC inverter is obtained; if so, control the renewable energy device to output the renewable energy to the DC inverter; otherwise, control the renewable energy device to output the renewable energy to the energy storage device.

[0009] Preferably, the main control module is also used to: obtain the current time period; if the current time period is in the preset daytime period, control the DC input power supply, the renewable energy device and the energy storage device to power the DC inverter based on a first control strategy, and the first control strategy gives priority to controlling the energy storage device to power the DC inverter; if the current time period is in the preset nighttime period, control the DC input power supply, the renewable energy device and the energy storage device to power the DC inverter based on a second control strategy, and the second control strategy gives priority to controlling the DC input power supply to power the DC inverter.

[0010] Preferably, the controlling the DC input power supply, the renewable energy device and the energy storage device to power the DC inverter based on the first control strategy includes: obtaining the connection status and current power of the energy storage device; when the energy storage device and the DC inverter are in a connected state, if the current power is less than a first preset power, controlling the DC inverter to connect to the DC input power supply and disconnect from the energy storage device; when the energy storage device and the DC inverter are in a disconnected state, if the current power is greater than a second preset power, controlling the DC inverter to connect to the energy storage device and disconnect from the DC input power supply, the first preset power is less than the second preset power.

[0011] Preferably, the controlling the DC input power supply, the renewable energy device and the energy storage device to supply power to the DC inverter based on the second control strategy includes: when the energy storage device is in a connected state, if the current power is less than a third preset power, controlling the DC inverter to connect to the DC input power supply and disconnect from the energy storage device, and the third preset power is greater than the first preset power and less than the second preset power; when the energy storage device is in a disconnected state, if the current power is greater than a fourth preset power, controlling the DC inverter to connect to the energy storage device and disconnect from the DC input power supply, and the fourth preset power is greater than the second preset power.

[0012] Preferably, the main control module is also used to: obtain historical regeneration data of the renewable energy device; generate a generation curve of renewable energy in unit time based on the historical regeneration data; obtain an energy consumption curve of total energy consumed in the unit time; determine the first preset power, the second preset power, the third preset power and the fourth preset power based on the generation curve and the energy consumption curve; generate a first control strategy based on the first preset power and the second preset power, and generate a second control strategy based on the third preset power and the fourth preset power.

[0013] Preferably, the determining of the first preset power, the second preset power, the third preset power and the fourth preset power based on the generation curve and the energy consumption curve includes: obtaining a daytime charge and discharge number threshold and a nighttime charge and discharge number threshold, the daytime charge and discharge number threshold being greater than the nighttime charge and discharge number threshold; when the current time period is in the preset daytime time period, determining the first preset power and the second preset power based on the daytime charge and discharge number threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the first preset power during the preset daytime time period; when the current time period is in the preset nighttime time period, determining the third preset power and the fourth preset power based on the nighttime charge and discharge number threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the third preset power during the preset nighttime time period.

[0014] Preferably, the main control module is also used to: obtain the first output current of the first semiconductor buck module, obtain the second output current of the second semiconductor buck module; determine whether there is an abnormality in at least one of the first output current, the first DC voltage, the second output current and the second DC voltage; if so, cut off the corresponding first semiconductor buck module and / or second semiconductor buck module, and output corresponding alarm information.

[0015] Correspondingly, the present invention further provides a DC elevator, which includes the DC elevator system described in the embodiment of the present invention.

[0016] Through the technical solution provided by the present invention, the present invention has at least the following technical effects: By improving the traditional AC elevator system and adopting a DC elevator driven by a DC power supply, all electrical components in the elevator system are replaced with DC drive components. The entire elevator can be operated with a DC input power supply combined with multiple semiconductor step-down modules, which reduces the cost of the elevator. At the same time, renewable energy can be directly used for elevator operation, thereby improving the economy of elevator operation.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0019] Figure 1 is a structural schematic diagram of a DC elevator system provided by an embodiment of the present invention;

[0020] Figure 2 It is a structural schematic diagram of a DC elevator system provided by a second embodiment of the present invention. DETAILED DESCRIPTION

[0021] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0022] The terms "system" and "network" in the embodiments of the present invention can be used interchangeably. "Multiple" means two or more than two. In view of this, "multiple" can also be understood as "at least two" in the embodiments of the present invention. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the previous and subsequent associated objects are in an "or" relationship. In addition, it should be understood that in the description of the embodiments of the present invention, the words "first", "second", etc. are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0023] An embodiment of the present invention provides a DC elevator system, which includes: a DC input power supply, a DC inverter and a DC traction machine; the DC input power supply is connected to the DC inverter to provide a DC input for the DC inverter; the DC inverter is connected to the DC traction machine to drive the DC traction machine; a first semiconductor buck module is connected to the DC input power supply to perform a buck operation and output a first DC voltage; a plurality of first DC components are connected to the first semiconductor buck module, each of which operates based on the first DC voltage; a second semiconductor buck module is connected to the first semiconductor buck module to perform a buck operation and output a second DC voltage; a plurality of second DC components are connected to the second semiconductor buck module, each of which operates based on the second DC voltage; the first DC voltage is lower than the voltage of the DC input, and the second DC voltage is lower than the first DC voltage.

[0024] See also Figure 1In a possible implementation, the existing elevator system is transformed into a DC system. Specifically, first, the input power of the elevator is replaced by a DC input power supply from the original 380V AC power supply or 220V AC power supply, for example, it is changed to a 700~750V DC input power supply, and a DC inverter is connected to the DC input power supply. The DC inverter drives the DC traction machine to operate according to the DC input to achieve the normal operation of the elevator, and then the first semiconductor step-down module is connected to the DC input power supply to perform a step-down operation on it and reduce it to a first DC voltage. For example, the first DC voltage is a 310V DC input. The first DC voltage is used to power multiple first DC components, and the first DC components include but are not limited to the elevator's main control cabinet, safety protection device, car lighting, shaft lighting and other components. That is, all of the above components are replaced from the original AC components to DC components, so as to better meet the development needs of new technologies.

[0025] Furthermore, since there are components driven by other voltage specifications in the elevator, a second semiconductor buck module is also configured, connected to the first semiconductor buck module, for bucking it into a second DC voltage, for example, the second DC voltage is a 110V DC input, for driving second DC components such as safety protection devices and brakes. In an embodiment of the present invention, a third semiconductor buck module is also configured, connected to the second semiconductor buck module, for bucking the second DC voltage into a third DC voltage, for example, a 24V DC input, and for providing power input for low-voltage DC components such as control circuit boards, sensors, elevator door machines, and hall call devices. In an embodiment of the present invention, the semiconductor buck module is a buck module based on third-generation semiconductor materials (gallium nitride or silicon carbide), which has good power conversion efficiency and higher safety.

[0026] In the embodiment of the present invention, by performing DC improvement on the traditional elevator system, the electrical components of the entire elevator system are all composed of DC components, so that only one DC input power supply is configured for the elevator during operation. Combined with multiple semiconductor step-down modules, the normal operation of the entire elevator can be achieved, and there is no need to configure corresponding power supplies for elevator components driven by different voltages respectively, thereby effectively reducing the configuration cost of the elevator. At the same time, the semiconductor step-down module can effectively improve the power conversion efficiency and reduce the elevator operation cost. The higher safety of the semiconductor step-down module and its switching characteristics can further improve the safety of the elevator system.

[0027] See also Figure 2 In an embodiment of the present invention, the DC elevator system also includes a renewable energy device connected to the DC traction machine for generating renewable energy; the renewable energy device is also connected to an energy storage device, and the energy storage device is connected to the DC inverter.

[0028] In the embodiment of the present invention, by connecting the renewable energy device with the energy storage device, the DC renewable energy generated by the renewable energy device can be directly stored and used for subsequent use of the elevator, thereby effectively reducing the operating cost of the elevator and improving the economy of the elevator.

[0029] In an embodiment of the present invention, the first DC component includes a main control module, which is used to: determine whether the driving signal of the DC inverter is obtained; if so, control the renewable energy device to output the renewable energy to the DC inverter; otherwise, control the renewable energy device to output the renewable energy to the energy storage device.

[0030] In a possible implementation, the main control module is arranged in the main control cabinet, and the regenerative energy device is also directly connected to the DC inverter. During the operation of the elevator, the main control module determines whether the driving signal of the DC inverter is obtained. For example, in one embodiment, the elevator receives an external call signal from a certain floor station, so it needs to immediately control the elevator car to go to the floor station. At this time, the driving signal is issued, which means that it needs the input of electric energy to drive the DC traction machine to move the elevator car to the floor station. At this time, the main control module controls the regenerative energy device to output the regenerative energy directly to the DC inverter for its use, thereby effectively reducing the energy consumption during the operation of the elevator. At other times, when the elevator is parked at the floor station and is in standby state or the elevator is in heavy load down or light load up, if regenerative energy is generated at this time, since the DC inverter does not need input current, the main control module controls the regenerative energy device to output the regenerative energy to the energy storage device for storage for subsequent use.

[0031] In actual applications, energy storage devices, such as lithium battery modules or power battery packs, have high configuration costs, and current batteries have a fixed number of charge and discharge cycles. Therefore, if they are frequently charged and discharged, their service life will be reduced and the economic efficiency of configuring energy storage devices for electrical energy storage will be reduced.

[0032] In an embodiment of the present invention, the main control module is also used to: obtain the current time period; if the current time period is in a preset daytime period, control the DC input power supply, the renewable energy device and the energy storage device to power the DC inverter based on a first control strategy, and the energy storage device is preferentially controlled to power the DC inverter in the first control strategy; if the current time period is in a preset nighttime period, control the DC input power supply, the renewable energy device and the energy storage device to power the DC inverter based on a second control strategy, and the DC input power supply is preferentially controlled to power the DC inverter in the second control strategy.

[0033] In a possible implementation, the current time period is first obtained. If the current time period is in the preset daytime period, the electricity price is at a relatively high level at this time. Therefore, based on the first control strategy, the DC input power supply, the renewable energy device and the energy storage device are controlled to power the DC inverter. In an embodiment of the present invention, the DC input power supply, the renewable energy device and the energy storage device are controlled to power the DC inverter based on the first control strategy, including: obtaining the connection status and current power of the energy storage device; when the energy storage device and the DC inverter are in a connected state, if the current power is less than a first preset power, controlling the DC inverter to connect to the DC input power supply and disconnect from the energy storage device; when the energy storage device and the DC inverter are in a disconnected state, if the current power is greater than a second preset power, controlling the DC inverter to connect to the energy storage device and disconnect from the DC input power supply, and the first preset power is less than the second preset power.

[0034] Specifically, the electricity price is higher during the day, so it is more economical and has lower operating costs to give priority to the electric energy in the energy storage device to drive the elevator. First, the connection status and current power of the energy storage device are obtained. If the energy storage device is connected to the DC inverter, that is, the energy storage device is in a discharging state at this time. If it is monitored that its current power is less than the first preset power, such as the first preset power is 20%, the DC inverter is controlled to connect the DC input power supply and disconnect the energy storage device, so as to avoid using the energy storage device under low power conditions and causing greater damage to it. At this time, the energy storage device enters the charging mode; if the energy storage device is disconnected from the DC inverter, that is, the energy storage device is in the charging mode at this time, the current power of the energy storage battery is monitored, and when the current power is greater than the second preset power, for example, the second preset power is 40%, the DC inverter is controlled to connect to the energy storage device and disconnect the DC input power supply, so as to give priority to using the electric energy in the energy storage device for power supply, so as to achieve more economical elevator operation.

[0035] In the embodiment of the present invention, the energy storage device is preferentially configured to supply power for the elevator operation during the high electricity price period during the day, thereby improving the economy of the elevator operation and reducing its operating cost; at the same time, by adopting different power switching thresholds in the charging and discharging mode of the energy storage system, the frequent charging and discharging times of the energy storage system can be effectively avoided, thereby increasing the service life of the energy storage system.

[0036] On the other hand, if the current time period is in the preset night time period, that is, the electricity price level is low at this time, an external DC input power supply can be used for power supply in priority to reduce the frequency of use of the energy storage system and increase its service life.

[0037] In an embodiment of the present invention, the controlling of the DC input power supply, the renewable energy device and the energy storage device to supply power to the DC inverter based on the second control strategy includes: when the energy storage device is in a connected state, if the current power is less than a third preset power, controlling the DC inverter to connect to the DC input power supply and disconnect from the energy storage device, and the third preset power is greater than the first preset power and less than the second preset power; when the energy storage device is in a disconnected state, if the current power is greater than a fourth preset power, controlling the DC inverter to connect to the energy storage device and disconnect from the DC input power supply, and the fourth preset power is greater than the second preset power.

[0038] In one possible implementation, if the energy storage device is in a connected state with the DC inverter, that is, the energy storage device is in a discharge mode at this time, if the current power of the energy storage device is less than a third preset power, for example, the third preset power is 30%, the DC inverter is controlled to connect to an external DC input power supply and disconnect the energy storage device; if the energy storage device is in a disconnected state with the DC inverter, that is, the energy storage device is in a charging mode, then when it is monitored that the current power of the energy storage device is greater than a fourth preset power, for example, the fourth power is 60%, the DC inverter is controlled to connect to the energy storage device and disconnect from the DC input power supply, thereby achieving an optimal balance between using low-cost electricity and maximizing the service life of the energy storage device.

[0039] In the embodiment of the present invention, different control strategies are adopted for switching the input power of the elevator at different time stages to comprehensively balance the use of low-cost electric energy and maximize the service life of the energy storage device, thereby meeting the actual needs of users and improving the user experience.

[0040] In actual application, different elevators have different usage conditions, and the amount of renewable energy generated thereby is also different, and the economic performance that can be achieved thereby is also different. Therefore, the above fixed control strategy does not achieve the best economic performance.

[0041] In an embodiment of the present invention, the main control module is also used to: obtain historical regeneration data of the renewable energy device; generate a generation curve of renewable energy in unit time based on the historical regeneration data; obtain an energy consumption curve of total energy consumed in the unit time; determine the first preset power, the second preset power, the third preset power and the fourth preset power based on the generation curve and the energy consumption curve; generate a first control strategy based on the first preset power and the second preset power, and generate a second control strategy based on the third preset power and the fourth preset power.

[0042] In a possible implementation, in order to achieve the maximum operating cost reduction effect and optimize the service life of the energy storage device, the historical regeneration data of the renewable energy device is obtained, and the generation curve of the renewable energy generated by the renewable energy device in a unit time is determined based on the data, for example, the unit time is 1-7 days. At this time, the energy consumption curve of the total energy consumed by the elevator in the unit time is obtained, that is, the energy consumption curve of the entire elevator in the unit time. At this time, the economic efficiency of energy use is accurately analyzed based on the generation curve and the energy consumption curve to determine the optimal first preset power, second preset power, third preset power and fourth preset power, and the corresponding first control strategy and second control strategy are generated according to the determined optimal first preset power, second preset power, third preset power and fourth preset power, so as to achieve the above technical effect.

[0043] In an embodiment of the present invention, the determining of the first preset power, the second preset power, the third preset power and the fourth preset power based on the generation curve and the energy consumption curve includes: obtaining a daytime charge and discharge number threshold and a nighttime charge and discharge number threshold, the daytime charge and discharge number threshold being greater than the nighttime charge and discharge number threshold; when the current time period is in the preset daytime time period, the first preset power and the second preset power are determined based on the daytime charge and discharge number threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the first preset power during the preset daytime time period; when the current time period is in the preset nighttime time period, the third preset power and the fourth preset power are determined based on the nighttime charge and discharge number threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the third preset power during the preset nighttime time period.

[0044] In a possible implementation, firstly, a daytime charge and discharge number threshold and a nighttime charge and discharge number threshold are obtained. For example, the above two thresholds are thresholds set in advance by technicians based on acceptable charge and discharge times of the energy storage device, wherein the daytime charge and discharge number threshold is greater than the nighttime charge and discharge number threshold, so as to give priority to consuming electric energy in the energy storage device during the day and giving priority to reducing the charge and discharge times of the energy storage device at night.

[0045] According to the time period in which the elevator is running, if it is in the preset daytime period, the renewable energy generation rate in the preset daytime period is determined according to the generation curve, and the charging rate of the energy storage device can be determined according to the data, and the energy consumption rate in the energy storage device can be determined in combination with the energy consumption curve, thereby determining the next charging time interval of the energy storage device, based on which, the optimal first preset power and second preset power are determined according to the above-mentioned daytime charge and discharge number threshold, and based on the first preset power, the renewable energy is completely consumed in the preset daytime period; And, if the third preset power and the fourth preset power are determined based on the same principle during the preset night time period, the renewable energy is completely consumed during the preset night time period based on the third preset power. Thus, according to the above-mentioned optimal power setting value, the best control scheme can be generated to achieve the best elevator operation economic performance and the best number of charge and discharge times of the energy storage device, thereby ensuring its service life and meeting the actual needs of users.

[0046] In actual use, due to the use of semiconductor-based step-down modules, compared with traditional switching power supplies or relay devices, it is possible to monitor the output current and voltage of each semiconductor step-down module in real time, analyze elevator abnormalities, and provide timely prompts, thereby improving the safety of elevator use.

[0047] In an embodiment of the present invention, the main control module is also used to: obtain the first output current of the first semiconductor buck module, obtain the second output current of the second semiconductor buck module; determine whether there is an abnormality in at least one of the first output current, the first DC voltage, the second output current and the second DC voltage; if so, cut off the corresponding first semiconductor buck module and / or second semiconductor buck module, and output corresponding alarm information.

[0048] In a possible implementation, during the operation of the elevator, a first output current of the first semiconductor buck module and a second output current of the second semiconductor buck module are obtained, and whether there is an abnormality is determined based on the first output current, the first DC voltage, the second output current and the second DC voltage. For example, in the first embodiment, if it is monitored that the current output by a semiconductor buck module is significantly greater than the normal output current, it can be determined that there are abnormal electrical components in the electrical components loaded by the semiconductor buck module, and therefore the semiconductor buck module is immediately cut off, and a corresponding alarm message is immediately issued; in the second embodiment, if it is monitored that the DC voltage across a semiconductor buck module is significantly higher, it can be determined that there is an abnormality in the semiconductor buck module, and in order to protect the electrical components from damage, the semiconductor buck module is immediately cut off, and a corresponding alarm message is output.

[0049] In the embodiment of the present invention, by configuring a semiconductor step-down module and utilizing its own current monitoring and voltage monitoring functions, it is possible to monitor the current and voltage of various electrical components during the operation of the elevator without configuring additional monitoring devices, and detect abnormalities in a timely manner, thereby effectively improving the safety of the elevator operation.

[0050] Furthermore, an embodiment of the present invention also provides a DC elevator, which includes the DC elevator system described in the embodiment of the present invention.

[0051] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical scheme of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0052] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0053] In addition, various implementation modes of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed by the embodiments of the present invention.

Claims

1. A DC elevator system, characterized in that: The DC elevator system comprises: DC input power supply, DC inverter and DC traction machine; The DC input power supply is connected to the DC frequency converter and is used to provide a DC input for the DC frequency converter; The DC inverter is connected to the DC traction machine and is used to drive the DC traction machine; A first semiconductor step-down module, connected to the DC input power supply, configured to perform a step-down operation and output a first DC voltage; A plurality of first DC components connected to the first semiconductor step-down module, each of the first DC components operating based on the first DC voltage; A second semiconductor buck module, connected to the first semiconductor buck module, configured to perform a buck operation and output a second DC voltage; a plurality of second DC components connected to the second semiconductor step-down module, each of the second DC components operating based on the second DC voltage; The first DC voltage is lower than the voltage of the DC input, and the second DC voltage is lower than the first DC voltage.

2. The DC elevator system according to claim 1, characterized in that: The DC elevator system further includes a regenerative energy device connected to the DC traction machine, for generating regenerative energy; The renewable energy device is also connected to an energy storage device, and the energy storage device is connected to the DC inverter.

3. The DC elevator system according to claim 2, characterized in that: The first DC component includes a main control module, and the main control module is used for: Determining whether a driving signal of the DC inverter is obtained; If so, controlling the renewable energy device to output the renewable energy to the DC inverter; Otherwise, the renewable energy device is controlled to output the renewable energy to the energy storage device.

4. The DC elevator system according to claim 3, characterized in that: The main control module is also used for: Get the current period; If the current time period is in the preset daytime period, the DC input power supply, the renewable energy device and the energy storage device are controlled to supply power to the DC inverter based on a first control strategy, wherein the energy storage device is preferentially controlled to supply power to the DC inverter in the first control strategy; If the current time period is in the preset night time period, the DC input power supply, the renewable energy device and the energy storage device are controlled to power the DC inverter based on a second control strategy, and the DC input power supply is preferentially controlled to power the DC inverter in the second control strategy.

5. The DC elevator system according to claim 4, characterized in that: The method of controlling the DC input power supply, the renewable energy device and the energy storage device to supply power to the DC inverter based on the first control strategy includes: Obtaining the connection status and current power of the energy storage device; When the energy storage device is connected to the DC inverter, if the current power is less than a first preset power, control the DC inverter to connect to the DC input power supply and disconnect from the energy storage device; When the energy storage device and the DC inverter are in a disconnected state, if the current power is greater than a second preset power, the DC inverter is controlled to connect to the energy storage device and disconnect from the DC input power supply, and the first preset power is less than the second preset power.

6. The DC elevator system according to claim 5, characterized in that: The method of controlling the DC input power supply, the renewable energy device and the energy storage device to supply power to the DC inverter based on the second control strategy includes: When the energy storage device is connected to the DC inverter, if the current power is less than a third preset power, control the DC inverter to connect to the DC input power supply and disconnect from the energy storage device, and the third preset power is greater than the first preset power and less than the second preset power; When the energy storage device and the DC inverter are in a disconnected state, if the current power is greater than a fourth preset power, the DC inverter is controlled to connect to the energy storage device and disconnect from the DC input power supply, and the fourth preset power is greater than the second preset power.

7. The DC elevator system according to claim 6, characterized in that: The main control module is also used for: Obtaining historical regeneration data of the renewable energy device; Generate a generation curve of renewable energy per unit time based on the historical regeneration data; Obtaining an energy consumption curve of total energy consumed within the unit time; Determine the first preset power, the second preset power, the third preset power, and the fourth preset power based on the generation curve and the energy consumption curve; A first control strategy is generated based on the first preset power and the second preset power, and a second control strategy is generated based on the third preset power and the fourth preset power.

8. The DC elevator system according to claim 7, characterized in that: The determining the first preset power, the second preset power, the third preset power, and the fourth preset power based on the generation curve and the energy consumption curve includes: Obtaining a daytime charge and discharge number threshold and a nighttime charge and discharge number threshold, wherein the daytime charge and discharge number threshold is greater than the nighttime charge and discharge number threshold; When the current time period is in the preset daytime period, a first preset power quantity and a second preset power quantity are determined based on the daytime charge and discharge times threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the first preset power quantity in the preset daytime period; When the current time period is in the preset night time period, a third preset power amount and a fourth preset power amount are determined based on the night time charge and discharge times threshold, the generation curve and the energy consumption curve, and the renewable energy is completely consumed according to the third preset power amount during the preset night time period.

9. The DC elevator system according to claim 1, characterized in that: The main control module is also used for: Acquire a first output current of the first semiconductor buck module, and acquire a second output current of the second semiconductor buck module; determining whether at least one of the first output current, the first DC voltage, the second output current, and the second DC voltage is abnormal; If so, the corresponding first semiconductor buck module and / or second semiconductor buck module is cut off, and the corresponding alarm information is output.

10. A DC elevator, characterized in that: The DC elevator comprises a DC elevator system according to any one of claims 1-9.

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