Battery energy storage power supply device for elevator

Abstract

The present application provides a battery energy storage power supply device for an elevator, comprising a charger, an elevator driving unit, a battery stack, a reconfigurable switch, and an overcurrent protection unit. The battery energy storage power supply device for an elevator can be charged during off-peak electricity price periods of a mains power grid, and during peak electricity price periods of the utility grid, the battery energy storage power supply device is used to provide energy for the elevator. The battery energy storage power supply device for an elevator can also store the electricity generated by an elevator traction machine in a power generation state into the battery energy storage power supply device, and can also store low-price electric energy in the battery stack during off-peak periods of a power grid.

Description

An elevator battery energy storage power supply device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410487309.1, filed on April 22, 2024, entitled "An Elevator Battery Energy Storage Power Supply Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to power electronic converter technology and battery energy storage technology, particularly to converters, battery energy storage, elevator drives and other fields. Background Technology

[0004] Elevators, an ancient yet modern means of transportation, provide vertical lifting services for humans. Thanks to advancements in various technologies, especially power electronics, elevators have seen significant improvements in control and ride comfort. With increasing demands for energy conservation and emission reduction in modern society, people are focusing on energy-efficient elevator operation. Adding energy storage devices to the elevator drive system can achieve energy savings to some extent. When the weight on the elevator car side is greater than the weight on the counterweight side, the elevator traction machine operates in a generator state during descent, and its electrical energy flows back to the DC bus through the drive converter. Traditional elevators dissipate this energy using parallel braking resistors; otherwise, the DC bus voltage would rise, leading to accidents. The principle of elevator energy storage devices is to connect an energy storage device in parallel to the DC bus. This device stores the electrical energy output by the traction machine instead of dissipating it through braking resistors. This stored energy is returned to the DC bus at appropriate times, thus enabling energy-efficient elevator operation.

[0005] Due to the complex operating conditions of elevators and energy storage devices—elevators ascend and descend, and the car load varies constantly—the state of charge (SOC) of the energy storage device dynamically changes with operating time. This complexity makes it difficult to determine the operating state of the elevator energy storage device, leading to control challenges. Furthermore, current research on adding energy storage devices to elevators only focuses on single elevators. However, with the trend towards larger and higher-rise buildings, multiple elevators per building are becoming the norm. Equipping each elevator with its own energy storage device is clearly insufficient to meet the demands of modern development. Summary of the Invention

[0006] This application provides a converter device and its control method, which can store the electrical energy generated by the traction machine in the battery stack when it is in the power generation state, and can also store low-cost electrical energy in the battery stack during grid off-peak periods.

[0007] This application provides an elevator battery energy storage power supply device, comprising:

[0008] Charger;

[0009] Elevator drive unit;

[0010] Battery stack;

[0011] Variable structure switch;

[0012] Overcurrent protection unit;

[0013] in:

[0014] The elevator drive unit includes a voltage sensor, a current sensor, and several frequency converters, each of which drives one traction machine. The input terminals of each frequency converter are connected to the municipal power grid to obtain power from the grid. Each frequency converter is equipped with a DC bus, which is connected in parallel with the common bus of the elevator drive unit.

[0015] The charger provides charging current to the battery stack; the battery stack has a positive (+) terminal and a negative (-) terminal, and through the variable structure switch and overcurrent protector, the positive and negative terminals of the battery stack are respectively connected to the positive and negative terminals of the common bus of the elevator drive unit;

[0016] The variable structure switch is controlled according to the status of the municipal power grid and the peak-valley electricity price time.

[0017] The variable structure switch is controlled by the voltage and current sensors of the elevator drive unit;

[0018] The overcurrent protection unit activates when the current in the elevator drive unit exceeds a set threshold, disconnecting the battery stack from the common bus.

[0019] The variable structure switch includes a first switch, a second switch, a current-limiting resistor, and a circuit breaker; the circuit breaker includes a third and a fourth switch contact; the first switch and the current-limiting resistor are connected in series and then in parallel with the second switch, one end of which is connected to the positive terminal of the battery stack, and the other end is connected to one end of the third switch contact of the circuit breaker; the other end of the third switch contact of the circuit breaker is connected to the positive terminal of the common bus of the elevator drive unit, and one end of the fourth switch contact of the circuit breaker is connected to the negative terminal of the battery stack, and the other end is connected to the negative terminal of the common bus of the elevator drive unit.

[0020] The battery stack includes a battery management system and several battery modules connected in series. The positive terminal of the first battery module is the positive terminal of the battery stack, and the negative terminal of the last battery module is the negative terminal of the battery stack.

[0021] The battery module includes a battery module management system and several individual batteries connected in series. The positive terminal of the first individual battery is the positive terminal of the battery module, and the negative terminal of the last individual battery is the negative terminal of the battery module.

[0022] The single-cell battery consists of a positive electrode, a separator, a negative electrode, a polyoxymethylene (POM) solid electrolyte, and packaging materials. The POM solid electrolyte is formed by injecting an electrolyte solution containing trioxymethylene into the cell and then solidifying it in situ within the cell at 20-60°C. The POM in the solid electrolyte has a unique micro / nano structure that confines the electrolyte within this structure, preventing it from flowing freely.

[0023] The aforementioned solid-state lithium-ion and sodium-ion batteries containing polyoxymethylene do not contain freely flowing liquid electrolyte within the cell.

[0024] The structural changes of the contacts of the first switch, second switch, current-limiting resistor, and third and fourth switches of the variable structure switch are as follows:

[0025] When the voltage of the common bus of the elevator drive unit is higher than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus decreases over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the common bus charges the battery stack.

[0026] When the voltage of the common bus of the elevator drive unit is lower than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus rises over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the battery stack provides power to the elevator drive unit.

[0027] When the municipal power grid is in a low-voltage period, the charger charges the battery stack, and the elevator drive unit is powered by the municipal power grid. When the municipal power grid is in a high-voltage period, the charger stops charging the battery stack, and the elevator drive unit is powered by the battery stack.

[0028] The voltage of the battery stack is consistent with the voltage of the common bus of the elevator drive unit.

[0029] The elevator battery energy storage power supply device also includes a remote communication unit. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the first application example of the elevator battery energy storage power supply device of this application;

[0031] Figure 2 is a schematic diagram of the variable structure switch structure of this application;

[0032] Figure 3 is a schematic diagram of the battery stack structure of this application;

[0033] Figure 4 shows the structural schematic of the battery module in this application;

[0034] Figure 5 is a schematic diagram of the current-limiting mode of the variable structure switch in this application;

[0035] Figure 6 is a schematic diagram of the conduction modes of the variable structure switch of this application;

[0036] Figure 7 is a schematic diagram of the voltage change of the common bus when the battery stack of this application is powered by the common bus and the variable structure switch is in the current limiting mode.

[0037] Figure 8 is a schematic diagram of the voltage change of the common bus under the working conditions of traction machine power generation, common bus charging of battery stack, and variable structure switch under current limiting mode.

[0038] Figure 9 is a schematic diagram of a second application example of the elevator battery energy storage power supply device of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] It should be noted that when a component is described as "fixed to" another component, it can be directly on another component or it can be in the middle of another component. When a component is described as "connected to" another component, it can be directly connected to another component or it may be in the middle of another component.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] To at least partially address the problems existing in the prior art, such as the difficulty in controlling the charging of the battery stack by the power grid or traction machine, this application provides an elevator battery energy storage power supply device, wherein the elevator battery energy storage power supply device includes:

[0043] Charger;

[0044] Elevator drive unit;

[0045] Battery stack;

[0046] Variable structure switch;

[0047] Overcurrent protection unit;

[0048] in:

[0049] The elevator drive unit includes a voltage sensor, a current sensor, and several frequency converters, each of which drives one traction machine. The input terminals of each frequency converter are connected to the municipal power grid to obtain power from the grid. Each frequency converter is equipped with a DC bus, which is connected in parallel with the common bus of the elevator drive unit.

[0050] The charger provides charging current to the battery stack; the battery stack has positive and negative terminals, and through the variable structure switch and overcurrent protector, the positive and negative terminals of the battery stack are respectively connected to the positive and negative terminals of the common bus of the elevator drive unit.

[0051] The variable structure switch is controlled according to the status of the municipal power grid and the peak-valley electricity price time.

[0052] The variable structure switch is controlled by the voltage and current sensors of the elevator drive unit;

[0053] The overcurrent protection unit activates when the current in the elevator drive unit exceeds a set threshold, disconnecting the battery stack from the common bus.

[0054] The variable structure switch includes a first switch, a second switch, a current-limiting resistor, and a circuit breaker; the circuit breaker includes a third and a fourth switch contact; the first switch and the current-limiting resistor are connected in series and then in parallel with the second switch, one end of which is connected to the positive terminal of the battery stack, and the other end is connected to one end of the third switch contact of the circuit breaker; the other end of the third switch contact of the circuit breaker is connected to the positive terminal of the common bus of the elevator drive unit, and one end of the fourth switch contact of the circuit breaker is connected to the negative terminal of the battery stack, and the other end is connected to the negative terminal of the common bus of the elevator drive unit.

[0055] The battery stack includes a battery management system and several battery modules connected in series. The positive terminal of the first battery module is the positive terminal of the battery stack, and the negative terminal of the last battery module is the negative terminal of the battery stack.

[0056] The battery module includes a battery module management system and several individual batteries connected in series. The positive terminal of the first individual battery is the positive terminal of the battery module, and the negative terminal of the last individual battery is the negative terminal of the battery module.

[0057] The single-cell battery is a solid-state lithium-ion battery or a sodium-ion battery containing polyoxymethylene (POM). The POM-containing solid-state lithium-ion battery and sodium-ion battery consist of a positive electrode, a separator, a negative electrode, a POM solid electrolyte, and packaging materials. The POM solid electrolyte is formed by injecting an electrolyte solution containing trioxymethylene into the cell and then solidifying it in situ within the cell at 20-60°C.

[0058] The structural changes of the contacts of the first switch, second switch, current-limiting resistor, and third and fourth switches of the variable structure switch are as follows:

[0059] When the voltage of the common bus of the elevator drive unit is higher than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus decreases over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the common bus charges the battery stack.

[0060] When the voltage of the common bus of the elevator drive unit is lower than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus rises over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the battery stack provides power to the elevator drive unit.

[0061] When the municipal power grid is in a low-voltage period, the charger charges the battery stack, and the elevator drive unit is powered by the municipal power grid. When the municipal power grid is in a high-voltage period, the charger stops charging the battery stack, and the elevator drive unit is powered by the battery stack.

[0062] The voltage of the battery stack is consistent with the voltage of the common bus of the elevator drive unit.

[0063] The elevator battery energy storage power supply device also includes a remote communication unit.

[0064] Figure 1 is a schematic diagram of a first application example of the elevator battery energy storage power supply device of this application. The elevator battery energy storage power supply device shown in Figure 1 includes a charger 1, an elevator drive unit 2, a battery stack 3, a variable structure switch 4, and an overcurrent protection unit 5.

[0065] The charger 1 uses the industrial frequency AC power from the city power grid to charge the battery stack 3. The positive terminal of the battery stack 3 is connected to the positive terminal of the common bus of the elevator drive unit 2 through the variable structure switch 4 and the overcurrent protection unit 5, and the negative terminal of the battery stack 3 is connected to the negative terminal of the common bus of the elevator drive unit 2 through the variable structure switch 4 and the overcurrent protection unit 5.

[0066] The elevator drive unit 2 includes several frequency converters 21, each driving one traction machine. Each frequency converter has a positive DC bus terminal and a negative DC bus terminal, which are connected to the positive and negative terminals of a common bus, respectively. The elevator drive unit 2 includes several voltage sensors 22 and current sensors 23 for detecting the operating status of the elevator drive unit. The outputs of the voltage sensors 22 and current sensors 23 can be used to control the variable structure switch 4. The mains power grid provides power to the frequency converters.

[0067] Figure 2 is a schematic diagram of the variable structure switch of this application. Referring to Figure 2, the variable structure switch includes a first switch 41, a second switch 42, a current-limiting resistor 43, and a circuit breaker 44. The circuit breaker 44 includes a third switch contact 441 and a fourth switch contact 442. The first switch 41 and the current-limiting resistor 43 are connected in series and then in parallel with the second switch 42. One end of the first switch 41 is connected to the positive terminal of the battery stack 3, and the other end is connected to one end of the third switch contact 441 of the circuit breaker. The other end of the third switch contact 441 of the circuit breaker is connected to the positive terminal of the common bus of the elevator drive unit. One end of the fourth switch contact 442 of the circuit breaker is connected to the negative terminal of the battery stack 3, and the other end is connected to the negative terminal of the common bus of the elevator drive unit 2.

[0068] Figure 3 is a schematic diagram of the structure of the battery stack 3 of this application. Referring to Figure 3, the battery stack 3 includes a battery management system 31 and a plurality of battery modules 32, which are connected in series. The positive terminal of the first battery module is the positive terminal of the battery stack, and the negative terminal of the last battery module is the negative terminal of the battery stack.

[0069] Figure 4 shows the schematic diagram of the battery module structure of this application. As shown in Figure 4, the battery module 32 includes a battery module management system 321 and a plurality of individual batteries 322. The individual batteries are connected in series, with the positive terminal of the first individual battery being the positive terminal of the battery module 32 and the negative terminal of the last individual battery being the negative terminal of the battery module 32.

[0070] Figure 5 is a schematic diagram of the current-limiting mode of the variable structure switch 4 in this application. Figure 6 is a schematic diagram of the conduction mode of the variable structure switch in this application. Figure 7 is a schematic diagram of the common bus voltage change when the battery stack 3 is powered by the common bus and the variable structure switch is in the current-limiting mode. As shown in Figure 5, during the current-limiting mode of the variable structure switch, the circuit breaker 44 is turned on, the third switch contact 441 and the fourth switch contact 442 are closed, and the first switch 41 is turned on. Due to the current-limiting resistor 43, the common bus voltage increases over time as shown in Figure 7. When the common bus voltage is equal to the battery stack voltage, the variable structure switch 4 enters the conduction mode as shown in Figure 6. During the conduction mode of the variable structure switch, the first switch 41 is turned off, the second switch 42 is turned on, the battery stack is directly connected to the common bus, and the battery stack provides power to the elevator drive unit.

[0071] Figure 8 illustrates the voltage change of the common bus in the following operating conditions: traction machine power generation, common bus charging of the battery stack, and variable structure switch in current-limiting mode. When the common bus voltage is higher than the battery stack voltage, the circuit breaker 44 is turned on, and the third switch contact 441 and the fourth switch contact 442 are turned on. The first switch 41 is turned on, and the variable structure switch enters the current-limiting mode as shown in Figure 5. As shown in Figure 8, the common bus voltage decreases over time due to current limiting by the current-limiting resistor 43. When the common bus voltage equals the battery stack voltage, the first switch is turned off, the second switch is turned on, and the variable structure switch 4 enters the conduction mode as shown in Figure 6. The battery stack is directly connected to the common bus, and the common bus charges the battery stack.

[0072] Figure 9 is a schematic diagram of a second application of the elevator battery energy storage power supply device according to this application. The second application example of the elevator battery energy storage power supply device is based on the first application example of the elevator battery energy storage power supply device, with the addition of a remote communication unit. The remote communication unit can send the real-time operating status of the elevator battery energy storage power supply device to the upper-level control system, or the upper-level control system can issue commands to the elevator battery energy storage power supply device.

[0073] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes (but is not limited to) various media capable of storing program code, such as read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An elevator battery energy storage power supply device, characterized in that, include: Charger; Elevator drive unit; Battery stack; Variable structure switch; Overcurrent protection unit; in: The elevator drive unit includes a voltage sensor, a current sensor, and several frequency converters, each of which drives one traction machine. The input terminals of each frequency converter are connected to the municipal power grid to obtain power from the grid. Each frequency converter is equipped with a DC bus, which is connected in parallel with the common bus of the elevator drive unit. The charger provides charging current to the battery stack; the battery stack has positive and negative terminals, and through the variable structure switch and overcurrent protector, the positive and negative terminals of the battery stack are respectively connected to the positive and negative terminals of the common bus of the elevator drive unit. The variable structure switch is controlled according to the status of the municipal power grid and the peak-valley electricity price time. The variable structure switch is controlled by the voltage and current sensors of the elevator drive unit; The overcurrent protection unit activates when the current in the elevator drive unit exceeds a set threshold, disconnecting the battery stack from the common bus.

2. The elevator battery energy storage power supply device according to claim 1, characterized in that: The variable structure switch includes a first switch, a second switch, a current-limiting resistor, and a circuit breaker; the circuit breaker includes a third and a fourth switch contact; the first switch and the current-limiting resistor are connected in series and then in parallel with the second switch, one end of which is connected to the positive terminal of the battery stack, and the other end is connected to one end of the third switch contact of the circuit breaker; the other end of the third switch contact of the circuit breaker is connected to the positive terminal of the common bus of the elevator drive unit, and one end of the fourth switch contact of the circuit breaker is connected to the negative terminal of the battery stack, and the other end is connected to the negative terminal of the common bus of the elevator drive unit.

3. The elevator battery energy storage power supply device according to claim 1, characterized in that: The battery stack includes a battery management system and several battery modules connected in series. The positive terminal of the first battery module is the positive terminal of the battery stack, and the negative terminal of the last battery module is the negative terminal of the battery stack.

4. The elevator battery energy storage power supply device according to claim 3, characterized in that: The battery module includes a battery module management system and several individual batteries connected in series. The positive terminal of the first individual battery is the positive terminal of the battery module, and the negative terminal of the last individual battery is the negative terminal of the battery module.

5. An elevator battery energy storage power supply device according to claim 1 or 2, characterized in that: The structural changes of the contacts of the first switch, second switch, current-limiting resistor, and third and fourth switches of the variable structure switch are as follows: When the voltage of the common bus of the elevator drive unit is higher than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus decreases over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the common bus charges the battery stack. When the voltage of the common bus of the elevator drive unit is lower than the voltage of the battery stack, the circuit breaker is turned on, the third and fourth switch contacts are closed, the first switch is turned on, and the current is limited by the current limiting resistor. The voltage of the common bus rises over time. When the voltage of the common bus is equal to the voltage of the battery stack, the first switch is turned off, the second switch is turned on, the battery stack is directly connected to the common bus, and the battery stack provides power to the elevator drive unit.

6. The elevator battery energy storage power supply device according to claim 1, characterized in that: When the municipal power grid is in a low-voltage period, the charger charges the battery stack, and the elevator drive unit is powered by the municipal power grid. When the municipal power grid is in a high-voltage period, the charger stops charging the battery stack, and the elevator drive unit is powered by the battery stack.

7. The elevator battery energy storage power supply device according to claim 1, characterized in that: The voltage of the battery stack is consistent with the voltage of the common bus of the elevator drive unit.

8. The elevator battery energy storage power supply device according to claim 1, characterized in that: The elevator battery energy storage power supply device includes a remote communication unit.

9. The elevator battery energy storage power supply device according to claim 4, characterized in that: The individual cells are solid-state lithium-ion batteries and sodium-ion batteries containing polyoxymethylene, and there is no freely flowing electrolyte inside the cells.

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