Elevator transient energy recovery system based on super capacitor

Abstract

The invention relates to the technical field of elevators, in particular to an elevator transient energy recovery system based on a super capacitor, which comprises a power link module connected with a direct current bus in parallel, a super capacitor module is arranged in the power link module, and the power link module is used for storing transient pulse energy generated on the direct current bus; the signal sensing module is connected with the direct-current bus in parallel, and the signal sensing module is used for monitoring bus voltage on the direct-current bus; the circuit control module is connected with the signal sensing module and the power link module in parallel, and the circuit control module is used for controlling the power link module to store the transient pulse energy according to the bus voltage monitored by the signal sensing module, so that the transient pulse energy existing on the direct-current bus is accurately captured, and efficient cyclic utilization of the transient pulse energy is achieved.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and more specifically to an elevator transient energy recovery system based on a supercapacitor. Background Technology

[0002] Currently, the elevator market faces challenges in handling elevator braking energy due to inefficiency or additional problems. The most representative approaches include using braking resistors to dissipate energy and feeding the energy back to the power grid. While the braking resistor approach is simple in structure, it directly converts electrical energy into heat, resulting in wasted energy, increased elevator temperature, and additional air conditioning energy consumption. The energy feedback to the power grid approach involves an inverter process that can cause harmonic pollution to the grid, requiring complex filtering devices and facing grid connection approval and metering difficulties in some areas. Furthermore, its feedback efficiency is constrained by the quality of the power grid.

[0003] The existing solutions mentioned above cannot efficiently, reliably, and cost-effectively capture and process the transient pulse energy generated during elevator braking. This is because transient pulse energy is characterized by short duration and high peak power, making traditional batteries unsuitable due to insufficient power density and cycle life. Flywheel energy storage, on the other hand, presents challenges related to mechanical wear, noise, and maintenance. Therefore, accurately capturing transient pulse energy and achieving efficient on-site recycling has become a critical bottleneck in the current elevator technology field that urgently needs to be overcome. Summary of the Invention

[0004] To address the technical challenge of accurately capturing transient pulse energy and achieving efficient recycling, this application provides a supercapacitor-based elevator transient energy recovery system.

[0005] The transient energy recovery system for elevators based on supercapacitors provided in this application adopts the following technical solution: A transient energy recovery system for elevators based on supercapacitors, wherein the system is connected in parallel with the DC bus of the elevator frequency converter, comprising: Supercapacitor module; The power link module is connected in parallel with the DC bus and contains a supercapacitor module. The power link module is used to store the instantaneous pulse energy generated on the DC bus. The signal sensing module is connected in parallel with the DC bus and is used to monitor the bus voltage on the DC bus. The circuit control module is connected in parallel with the signal sensing module and the power link module. The circuit control module is used to control the power link module to store instantaneous pulse energy based on the bus voltage monitored by the signal sensing module.

[0006] Furthermore, the power link module also includes a bidirectional DC-DC converter; The first low-voltage side port and the second low-voltage side port of the bidirectional DC-DC converter are respectively connected to the two ends of the supercapacitor module; The first high-voltage side port and the second high-voltage side port of the bidirectional DC converter are respectively connected to the two ends of the DC bus.

[0007] Furthermore, the power link module also includes a grid-connected switch unit; The grid-connected switch unit is connected in series between the elevator power grid and the input side of the elevator frequency converter.

[0008] Furthermore, the signal sensing module includes a bus voltage detection unit; The bus voltage detection unit is connected in parallel to the DC bus.

[0009] Furthermore, the signal sensing module also includes a power grid current detection unit; The grid current detection unit is connected in series between the grid-connected switch unit and the elevator frequency converter.

[0010] Furthermore, the circuit control module includes a control unit; The first signal input terminal of the control unit is connected to the bus voltage detection unit, the second signal input terminal of the control unit is connected to the grid current detection unit, the first signal output terminal of the control unit is connected to the bidirectional DC-DC converter, and the second signal output terminal of the control unit is connected to the grid-connected switch unit.

[0011] Furthermore, the circuit control module also includes a power calculation unit; The input terminals of the power calculation unit are connected to the bus voltage detection unit and the grid current detection unit, respectively, and the output terminals of the power calculation unit are connected to the control unit, the bidirectional DC-DC converter and the grid-connected switch unit, respectively.

[0012] Beneficial effects achieved: This application provides a transient energy recovery system for elevators based on supercapacitors. The system is characterized by being connected in parallel with the DC bus of the elevator inverter. The transient energy recovery system includes: a power link module connected in parallel with the DC bus, containing a supercapacitor module, used to store instantaneous pulse energy generated on the DC bus; a signal sensing module connected in parallel with the DC bus, used to monitor the bus voltage on the DC bus; and a circuit control module connected in parallel with the signal sensing module and the power link module, used to control the power link module to store instantaneous pulse energy based on the bus voltage monitored by the signal sensing module.

[0013] The reason why this application can solve the problem of accurately capturing transient pulse energy and achieving efficient recycling lies in the fact that it achieves real-time monitoring of the bus voltage through the direct parallel connection of the signal sensing module and the DC bus. This allows for the accurate capture of the transient pulse energy characteristic signal generated by the rise in DC bus voltage during braking. Subsequently, the circuit control module triggers the action of the power link module based on this characteristic signal. The supercapacitor module, with its inherent high power density and fast charging and discharging characteristics, can efficiently absorb the transient pulse energy appearing on the DC bus, thus completing the accurate capture of transient pulse energy. At the same time, the power link module stores the energy in the supercapacitor module, providing a recyclable energy source for subsequent high-power demand scenarios such as elevator start-up. This elevator transient energy recovery system achieves a closed loop from accurate identification and rapid capture to efficient storage and reuse through the coordinated work of the above three modules, effectively solving the problems of low capture efficiency and difficult recycling caused by traditional solutions being unable to cope with transient high-power energy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a transient energy recovery system for elevators based on supercapacitors, as described in this application. Figure 2 This is a topology diagram of a supercapacitor-based elevator transient energy recovery system according to this application; Figure 3 This application is based on Figure 2 A schematic diagram illustrating the steps that can be achieved by the proposed topology.

[0015] Explanation of icon numbers: 10. Power link module; 101. Supercapacitor module; DC-DC, bidirectional DC-DC converter; 102. Grid-connected switching unit; 20. Signal sensing module; 201. Bus voltage detection unit; 202. Grid current detection unit; 30. Circuit control module; 301. Control unit; 302. Power calculation unit; 40. Elevator power grid; DC-BUS, DC bus; 50. Elevator frequency converter. Detailed Implementation

[0016] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0017] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0019] This application discloses an elevator transient energy recovery system based on a supercapacitor.

[0020] Please refer to Figure 1 The schematic diagram of a supercapacitor-based elevator transient energy recovery system proposed in this embodiment includes: A power link module 10 is connected in parallel with the DC-BUS bus. The power link module 10 includes a supercapacitor module 101 and is used to store the instantaneous pulse energy generated on the DC-BUS bus. A signal sensing module 20 is also connected in parallel with the DC-BUS bus and is used to monitor the bus voltage on the DC-BUS bus. A circuit control module 30 is connected in parallel with the signal sensing module 20 and the power link module. The circuit control module 30 is used to control the power link module 10 to store the instantaneous pulse energy based on the bus voltage monitored by the signal sensing module 20.

[0021] It should be noted that the elevator transient energy recovery system proposed in this embodiment is connected in parallel with the DC bus of the elevator inverter 50.

[0022] The core purpose of connecting the elevator transient energy recovery system in parallel with the DC bus (DC-BUS) of the elevator inverter 50 is to directly intervene in the core transmission path of the elevator's power energy, thereby capturing transient pulse energy. Through the parallel connection of the signal sensing module 20 with the DC bus (DC-BUS), the bus voltage is tracked in real time, accurately capturing the instantaneous pulse energy generated by braking energy. Then, the circuit control module 30 controls the supercapacitor module 101 in the power link module 10 to perform rapid energy throughput based on the captured instantaneous pulse energy. This allows the instantaneous pulse energy that was previously consumed by resistors to be directly captured and stored in the supercapacitor, thereby providing regenerative energy that can be called upon immediately for subsequent elevator operation. Ultimately, this achieves on-site recycling of transient pulse energy, effectively improving the overall energy efficiency of the elevator system.

[0023] In one feasible implementation, the topology of the elevator transient energy recovery system based on a supercapacitor proposed in this embodiment can be shown as follows: Figure 2 As shown: The power link module 10 also includes a bidirectional DC-DC converter, the first low-voltage side port and the second low-voltage side port of which are respectively connected to the two ends of the supercapacitor module 101; the first high-voltage side port and the second high-voltage side port of which are respectively connected to the two ends of the DC bus DC-BUS.

[0024] The core function of the bidirectional DC-DC converter in the elevator transient energy recovery system is to serve as a controlled bidirectional energy flow path. Its low-voltage side port is connected to the supercapacitor module 101 to adapt to the working voltage of the supercapacitor module 101 and realize its rapid charging and discharging control. Its high-voltage side port is connected to the DC bus DC-BUS to realize the energy interaction between the elevator transient energy recovery system and the elevator power energy.

[0025] Through the aforementioned port connections, the bidirectional DC-DC converter can switch between buck charging mode and boost discharging mode according to control commands. When elevator braking causes a momentary increase in the DC bus voltage, it switches to buck charging mode to convert the instantaneous pulse energy on the DC bus into low-voltage energy suitable for storage in the supercapacitor module 101 for rapid absorption. When the elevator requires a large current to start, it switches to boost discharging mode to raise the low-voltage energy stored in the supercapacitor module 101 to the bus voltage level and release it back to the DC bus to power the elevator, thus accurately and efficiently capturing and recycling transient pulse energy.

[0026] The power link module 10 also includes a grid-connected switch unit 102, which is connected in series between the elevator power grid 40 and the input side of the elevator inverter 50.

[0027] In this embodiment, the grid-connected switch unit 102 serves as an intelligent control switch for the power grid supply channel. Its connection method between the elevator power grid 40 and the input side of the elevator inverter 50 allows the grid-connected switch unit 102 to directly switch the power transmission path from the power grid to the elevator system. When the supercapacitor module 101 has sufficient power, it remains disconnected to force the release of power from the capacitor. It only closes when the capacitor power is insufficient to allow the power grid to supplement the power supply, thereby realizing a capacitor-priority energy dispatch strategy.

[0028] The power link module 10, composed of a bidirectional DC-DC converter, a supercapacitor module 101, and a grid-connected switch unit 102, enables controllable bidirectional energy flow between the supercapacitor module 101 and the DC-BUS via the DC-DC converter. The grid-connected switch unit 102 manages the on / off switching of power from the grid. These three components work together to form a complete energy storage, release, and switching path. When the elevator starts, the circuit control module 30 prioritizes using the instantaneous pulse energy stored in the supercapacitor module 101 for power supply. At this time, the grid-connected switch remains open to achieve forced local circulation of the instantaneous pulse energy. Only when the energy in the supercapacitor module 101 is insufficient is the grid-connected switch immediately closed to introduce supplementary power from the grid. This maximizes energy saving while ensuring that elevator operation is not affected and completely eliminates harmonic pollution caused by instantaneous pulse energy feeding back to the grid.

[0029] The signal sensing module 20 includes a bus voltage detection unit 201, which is connected in parallel to the DC bus DC-BUS.

[0030] The bus voltage parameters of the DC bus DC-BUS are acquired in real time by the bus voltage detection unit 201. It is connected to the DC bus DC-BUS in parallel and performs non-intrusive sampling of the bus voltage with high input impedance, thereby ensuring that the true instantaneous value of the bus voltage is captured completely without consuming almost no bus power.

[0031] This direct parallel connection method enables the electrical signal of the bus voltage detection unit 201 to be strictly synchronized with the changes in the bus voltage. This allows the instantaneous pulse energy fluctuations representing the energy state on the DC bus (DC-BUS) during braking or starting to be converted into signals recognizable by the circuit control module 30 without delay. This provides the most direct and rapid basis for judging the braking state, enabling the circuit control module 30 to accurately determine whether the elevator is in a braking state or a starting / accelerating state based on the actual bus voltage, and immediately trigger the corresponding energy storage or release command accordingly. Ultimately, this achieves rapid response and precise management of transient pulse energy.

[0032] The signal sensing module 20 also includes a grid current detection unit 202, which is connected in series between the grid-connected switch unit 102 and the elevator frequency converter 50.

[0033] The grid current detection unit 202 is used to measure the current value actually input from the grid to the elevator system. Its connection between the grid-connected switch unit 102 and the elevator inverter 50 ensures that the grid current detection unit 202 can directly monitor the only current path flowing through the grid-connected switch unit 102, thereby accurately obtaining the grid current data provided by the grid alone, and thus providing the circuit control module 30 with a direct basis for judging the energy dispatch status.

[0034] When the elevator starts, if the supercapacitor module 101 can independently meet the elevator's power requirements, the current detected by the grid current detection unit 202 should be zero. Conversely, when the supercapacitor module 101 is underpowered, the grid current detection unit 202 will monitor the occurrence of grid supplementary current in real time. This enables the elevator transient energy recovery system to accurately control the execution status of the capacitor-priority power supply and grid supplementary insufficient strategy, and to achieve precise management of grid energy input and accurate measurement of energy-saving effects.

[0035] In the signal sensing module 20, the bus voltage fluctuation of the DC-BUS can be monitored in real time through the bus voltage detection unit 201 to directly determine whether the elevator is in an energy-consuming start / acceleration state or an energy-generating braking state. At the same time, the grid current detection unit 202 measures the magnitude of the grid current input from the grid to assess whether the power supply capacity of the supercapacitor module 101 is sufficient and the amount of supplementary energy from the grid. The two work together to provide the control unit 301 and the power calculation unit 302 with all the key parameters of the overall energy supply and demand status of the elevator transient energy recovery system, thus laying an indispensable decision-making foundation for realizing the precise energy scheduling strategy of capacitor priority power supply and grid supplementation on demand.

[0036] It should be noted that the grid current detection unit 202 obtains the actual grid current by measuring the instantaneous value of the current flowing through it in real time. When the elevator starts, if the control unit 301 has instructed the supercapacitor module 101 to discharge, but the current value detected by the grid current detection unit 202 is always zero or extremely small, it proves that the power provided by the supercapacitor module 101 alone is sufficient to meet the elevator's needs and its capacity is sufficient without grid intervention. Conversely, if the grid current is detected to start rising, it indicates that the power supply capacity of the supercapacitor module 101 can no longer fully meet the elevator's load demand. At this time, the specific value of the grid current is the energy value that needs to be supplemented by the grid. The control unit 301 can achieve seamless switching and power balance between capacitor power supply and grid supplementation by maintaining the stability of this current.

[0037] The circuit control module 30 includes a control unit 301. The first signal input terminal of the control unit 301 is connected to the bus voltage detection unit 201, the second signal input terminal of the control unit 301 is connected to the grid current detection unit 202, the first signal output terminal of the control unit 301 is connected to the bidirectional DC-DC converter, and the second signal output terminal of the control unit 301 is connected to the grid-connected switch unit 102.

[0038] As the core decision-maker of the elevator transient energy recovery system, the control unit 301 receives corresponding signals and issues control commands to coordinate the operation of the entire elevator transient energy recovery system. The control unit 301, connected to the bus voltage detection unit 201, directly acquires the real-time voltage value of the DC-BUS, thereby accurately determining whether the elevator is in a braking state requiring energy feedback or a starting state requiring energy replenishment. The control unit 301, connected to the grid current detection unit 202, monitors the actual current supplied by the grid, thereby determining whether the power supply capacity of the supercapacitor module 101 is sufficient to meet the current elevator load demand. The control unit 301, connected to the bidirectional DC-DC converter, directly drives the bidirectional DC-DC converter to operate in boost discharge mode or buck charging mode by sending control commands such as PWM modulation signals, achieving precise control of the energy throughput of the supercapacitor module 101. The control unit 301, connected to the grid-connected switch unit 102, directly controls the on / off state of the grid-connected switch unit 102 according to the energy scheduling strategy, thereby determining whether to introduce grid power.

[0039] By establishing the above connection, the control unit 301 can continuously compare the bus voltage status with the grid current data. When the elevator starts, it prioritizes instructing the bidirectional DC-DC converter to release energy from the supercapacitor module 101. Only when the power of the supercapacitor module 101 is insufficient is it immediately instructed to close the grid-connected switch unit 102 to supplement the grid power supply, thereby realizing the precise scheduling of transient pulse energy and maximizing local recycling, while ensuring that the power demand of the elevator operation is seamlessly met.

[0040] The circuit control module 30 also includes a power calculation unit 302. The input terminal of the power calculation unit 302 is connected to the bus voltage detection unit 201 and the grid current detection unit 202, respectively. The output terminal of the power calculation unit 302 is connected to the control unit 301, the bidirectional DC-DC converter and the grid-connected switch unit 102, respectively.

[0041] The power calculation unit 302 is used to perform real-time calculations on the collected raw electrical parameters to obtain the power dynamic information required by the elevator transient energy recovery system.

[0042] In this embodiment, the input terminal of the power calculation unit 302 is connected to the bus voltage detection unit 201 and the grid current detection unit 202 respectively. The purpose is to simultaneously obtain the DC-BUS voltage change trend and the real instantaneous value of the grid current, so as to provide an accurate data basis for calculating the instantaneous power demand of elevator operation and the actual supplementary power of the grid.

[0043] The output of the power calculation unit 302 is connected to the control unit 301, the bidirectional DC-DC converter, and the grid-connected switch unit 102, respectively. Its purpose is to send the calculated real-time power data to the control unit 301 so that the control unit 301 can make intelligent scheduling decisions based on this data, and enable the bidirectional DC-DC converter and the grid-connected switch unit 102 to achieve rapid response.

[0044] The circuit control module 30, composed of the control unit 301 and the power calculation unit 302, integrates the decision-making function of the control unit 301 with the calculation function of the power calculation unit 302 through this collaborative division of labor. This enables precise perception, rapid calculation, and intelligent allocation of the power flow of the elevator transient energy recovery system. The system can dynamically compare the power supply capacity of the supercapacitor module 101 with the instantaneous power demand of the elevator at a speed of milliseconds. Based on this, it can precisely control the output power of the bidirectional DC-DC converter and the on / off timing of the grid-connected switch unit 102. Thus, while ensuring that the elevator operation is not affected in any way, it strictly follows the capacitor priority principle, maximizes the energy-saving effect, and achieves efficient, smooth, and seamless scheduling of transient energy.

[0045] It should be noted that the real-time power data in this embodiment may include the elevator's required power, the power provided by the supercapacitor module 101, and the power supplemented by the power grid. Specifically, the power calculation unit 302 collects the bus voltage and the real-time operating current flowing through the DC-BUS to provide driving force for the elevator traction machine, and calculates the elevator's required power according to the power formula P=UI. Simultaneously, it calculates the elevator's required power based on the real-time monitored terminal voltage and internal resistance parameters of the supercapacitor module 101 using the formula... The power that the supercapacitor module 101 can provide under the current state is calculated. Finally, the power demand of the elevator is compared with the power that the supercapacitor module 101 can provide in real time, and the difference is the power supplement to the grid required.

[0046] Where P represents the elevator's required power; U represents the bus voltage; and I represents the real-time operating current. This indicates the power that the supercapacitor module 101 can provide; This indicates the terminal voltage of the supercapacitor module 101; This indicates the internal resistance of the supercapacitor module 101.

[0047] Furthermore, it should be noted that the reason why both the control unit 301 and the power calculation unit 302 in this embodiment are connected to the bus voltage detection unit 201 and the grid current detection unit 202 is to construct multiple independent information and control paths to maximize the reliability, safety, and response speed of the elevator transient energy recovery system. The reason why the control unit 301 cannot be connected only to the power calculation unit 302 is that the power calculation unit 302 itself may malfunction or experience communication delays. If it becomes the only information channel, the control unit 301 will completely fail due to information interruption. Therefore, the control unit 301 must establish a direct connection with the bus voltage detection unit 201 to obtain the most raw data to perform the highest priority fault judgment and system protection. For example, when the bus voltage is detected to momentarily exceed the safety limit, the control unit 301 can bypass any calculation logic and directly instruct the executor (i.e., the bidirectional DC-DC converter, the grid-connected switch unit 10). 2) Stop working; at the same time, the control unit 301 needs to communicate directly with the power grid current detection unit 202 to achieve rapid overcurrent protection, and is directly connected to the actuator to ensure the shortest and most deterministic control command path; this architecture allows the control unit 301 to independently acquire critical states and implement low-level safety monitoring while the power calculation unit 302 provides advanced power parameters for optimized scheduling, thus forming a dual redundancy mechanism of performance optimization by the calculation unit and safety assurance by the control unit 301, fundamentally avoiding the risk of single point of failure and meeting the highest requirements of elevator system for safety and reliability.

[0048] The reason why both the control unit 301 and the power calculation unit 302 in this embodiment are connected to the bidirectional DC-DC converter and the grid-connected switch unit 102 is to achieve parallel processing of instructions and functional layering, so as to achieve optimal dynamic response speed and control reliability. As a high-speed computing core, the power calculation unit 302 directly connects to the actuator to feed the real-time calculated power data directly to the drive logic inside the bidirectional DC-DC converter and the trigger circuit of the grid-connected switch unit 102 with extremely low latency. This allows the actuator to complete parameter preset and action preparation before receiving the formal instruction from the control unit 301, which is equivalent to pre-aiming. As the final decision-making core, the control unit 301 directly connects to issue the final, highest-authority execution or abort instruction based on a more comprehensive system status (including the results of the power calculation unit 302 and other logical judgments). This architecture enables the power calculation unit 302 to be responsible for high-speed and precise micro-adjustment, while the control unit 301 is responsible for safe decision-making. The two work together to ensure millisecond-level response capability to commands during transient processes, and to ensure that the control unit 301 always has the final decision-making power. Thus, while pursuing extremely high dynamic performance, it also builds a safety redundancy to prevent malfunctions or overloads.

[0049] Among them, the bidirectional DC-DC converter can be model DCM3623T50T13A6T70; the grid-connected switch unit can be model 3RT2015-1AP00; the bus voltage detection unit can be model LV100-400; the grid current detection unit can be model HAH1DRS1000S; the control unit can be model STM32F407VGT6; and the power calculation unit can be model XC7A35T.

[0050] Furthermore, Figure 2 The overall process that can be achieved by the proposed topology graph is as follows: Figure 3 As shown: When the elevator enters the start state or is in operation (i.e.) Figure 3 In S1), the bus voltage detection unit and the grid current detection unit detect the bus voltage and / or grid current in real time (i.e., Figure 3 (S2 in the text) At the same time, the control unit determines whether the bus voltage is rising or falling based on the bus voltage detected by the bus voltage detection unit. Figure 3 In step S3), if the bus voltage is determined to be rising at this time, it indicates that the elevator is in braking mode and there is instantaneous pulse energy. Therefore, the control unit sends a PWM modulation signal control command to the bidirectional DC-DC converter to drive the bidirectional DC-DC converter to work in buck charging mode to store the instantaneous pulse energy in the supercapacitor module. Then, the bus voltage detection unit detects the change in bus voltage in real time (i.e., Figure 3 (S4 in the middle).

[0051] If the bus voltage is determined to be low at this time, it indicates that the elevator is in a start / acceleration state. The control unit then obtains the elevator's required power calculated by the power calculation unit based on the connected bus voltage and grid current, the power that the supercapacitor module can provide, and the grid supplementary power (i.e., Figure 3 (S5 in the text) Based on the power that the supercapacitor module can provide, determine the state of charge (i.e., ...) of the supercapacitor module. Figure 3 (S6 in the middle).

[0052] If it is determined that the state of charge of the supercapacitor module is insufficient to support the elevator's start / acceleration operation, the control unit directly controls the grid-connected switch unit to turn on, opening the grid power supply channel. After connecting the grid voltage to supply power for the elevator's start / acceleration operation, the bus voltage detection unit and grid current detection unit then monitor the bus voltage and grid current in real time (i.e., ...). Figure 3 (S7 in the middle).

[0053] If it is determined that the state of charge of the supercapacitor module is sufficient to support the elevator's start-up / acceleration operation, the control unit drives the bidirectional DC-DC converter to operate in boost discharge mode to release the energy stored in the supercapacitor module and provide power for the elevator's start-up / acceleration operation (i.e., Figure 3 In step S8), the power calculation unit compares the power supply capacity of the supercapacitor module with the instantaneous power demand of the elevator in real time to determine whether the state of charge of the supercapacitor module can meet the current instantaneous power demand of the elevator (i.e., Figure 3 (S9 in the middle).

[0054] If it is determined that the state of charge of the supercapacitor module can meet the instantaneous power demand of the elevator, the control unit keeps the grid-connected switch unit in the open state to ensure that the power supply is entirely provided by the supercapacitor module. Then, the bus voltage is monitored in real time by the bus voltage detection unit (i.e., Figure 3 (S10 in the middle).

[0055] If it is determined that the state of charge of the supercapacitor module is insufficient to meet the instantaneous power demand of the elevator, the control unit controls the grid-connected switch unit to connect to the grid voltage, which supplements the difference in instantaneous power demand. Then, the bus voltage detection unit and the grid current detection unit continuously monitor the bus voltage and grid current (i.e., ...) in real time. Figure 3 (S11 in the middle).

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A transient energy recovery system for elevators based on supercapacitors, characterized in that, The elevator transient energy recovery system is connected in parallel with the DC bus of the elevator frequency converter. The elevator transient energy recovery system includes: A power link module is connected in parallel with the DC bus. The power link module is equipped with a supercapacitor module and is used to store the instantaneous pulse energy generated on the DC bus. A signal sensing module is connected in parallel with the DC bus and is used to monitor the bus voltage on the DC bus. A circuit control module is connected in parallel with the signal sensing module and the power link module. The circuit control module is used to control the power link module to store the instantaneous pulse energy based on the bus voltage monitored by the signal sensing module.

2. The elevator transient energy recovery system based on supercapacitors according to claim 1, characterized in that, The power link module also includes a bidirectional DC-DC converter; The first low-voltage side port and the second low-voltage side port of the bidirectional DC-DC converter are respectively connected to the two ends of the supercapacitor module; The first high-voltage side port and the second high-voltage side port of the bidirectional DC converter are respectively connected to the two ends of the DC bus.

3. The elevator transient energy recovery system based on supercapacitors according to claim 2, characterized in that, The power link module also includes a grid-connected switch unit; The grid-connected switch unit is connected in series between the elevator power grid and the input side of the elevator frequency converter.

4. The elevator transient energy recovery system based on supercapacitors according to claim 3, characterized in that, The signal sensing module includes a bus voltage detection unit; The bus voltage detection unit is connected in parallel to the DC bus.

5. The elevator transient energy recovery system based on supercapacitors according to claim 4, characterized in that, The signal sensing module also includes a power grid current detection unit; The grid current detection unit is connected in series between the grid-connected switch unit and the elevator frequency converter.

6. The elevator transient energy recovery system based on supercapacitors according to claim 5, characterized in that, The circuit control module includes a control unit; The first signal input terminal of the control unit is connected to the bus voltage detection unit, the second signal input terminal of the control unit is connected to the grid current detection unit, the first signal output terminal of the control unit is connected to the bidirectional DC-DC converter, and the second signal output terminal of the control unit is connected to the grid-connected switch unit.

7. The elevator transient energy recovery system based on supercapacitors according to claim 6, characterized in that, The circuit control module also includes a power calculation unit; The input terminal of the power calculation unit is connected to the bus voltage detection unit and the grid current detection unit, respectively, and the output terminal of the power calculation unit is connected to the control unit, the bidirectional DC-DC converter and the grid-connected switch unit, respectively.

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