Energy storage elevator
By using DC-DC energy conversion modules and monitoring circuits in energy storage elevators, the number of energy conversion stages is simplified, solving the problems of high energy consumption and insufficient emergency response capabilities of traditional energy storage elevators, and achieving efficient energy conversion and stable power supply.
Patent Information
- Application Number
- CN202422943937.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-29
AI Technical Summary
Traditional energy storage elevators have high energy consumption and insufficient emergency response capabilities when the power grid is out of service or malfunctions. The multiple energy conversion stages lead to large energy losses and unstable elevator operation.
The DC-DC energy conversion module is directly connected to the battery energy storage module and the DC bus capacitor of the frequency converter, simplifying it to a single-stage conversion. Combined with monitoring circuits and emergency modules, it achieves efficient conversion of elevator potential energy into electrical energy and provides emergency power supply.
It reduces energy consumption, improves the safety and reliability of elevator operation, and ensures normal operation even during power grid failures.
Smart Images
Figure CN223495922U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of elevator technology, and in particular to an energy storage elevator. Background Technology
[0002] As an important means of transportation in modern buildings, elevators are increasingly attracting attention due to their energy consumption and safety issues. Traditional elevator systems mostly rely on direct power supply from the grid, which not only results in high energy consumption but also affects elevator operation during power outages or malfunctions.
[0003] Traditional energy storage elevators primarily employ a two-stage DC / DC / AC conversion method during battery discharge. The resulting AC power is connected to the R / S / T input of the frequency converter, powering the converter to drive the elevator traction machine. While this two-stage DC / DC / AC conversion achieves the mutual conversion between potential energy and electrical energy, the high number of conversion stages in this intermediate energy conversion module results in significant energy loss and hinders energy recycling. Utility Model Content
[0004] Therefore, the purpose of this utility model is to provide an energy storage elevator to solve the above-mentioned technical problems, which includes:
[0005] Elevator body, DC-DC energy conversion module, battery energy storage module, and control module;
[0006] The elevator body includes an elevator, a traction machine, and a frequency converter;
[0007] One end of the DC-DC energy conversion module is connected to the battery energy storage module, and the other end is connected to the DC bus capacitor of the frequency converter. The DC-DC energy conversion module is used to realize the conversion between elevator potential energy and electrical energy, and the energy conversion between the battery energy storage module and the elevator.
[0008] The control module is used to obtain the status of the elevator body and the battery energy storage module and switch the status of the DC-DC energy conversion module.
[0009] Furthermore, the battery energy storage module includes a monitoring circuit, which is connected to the control module; the monitoring circuit is used to detect whether the battery power exceeds a preset threshold, and if it does, it sends a power supply signal to the control module.
[0010] To prevent the battery from continuing to charge when it is fully charged, which could cause the DC bus capacitor voltage to spike, the battery storage module includes a monitoring circuit. This circuit determines the battery level and, when the battery level exceeds a certain storage capacity, provides parallel power. This avoids stopping charging after the battery is fully charged, thus preventing the need to rely on the braking resistor for heat dissipation. Parallel power supply also addresses the issue of insufficient grid voltage during peak electricity usage periods, which could lead to slower elevator speeds or elevator shutdowns.
[0011] Furthermore, the frequency converter includes a rectifier, a DC bus capacitor, an inverter, and a fault detection circuit;
[0012] The rectifier, the DC bus capacitor, and the inverter are connected in parallel. The fault detection circuit is connected to the rectifier, the DC bus capacitor, and the inverter respectively to detect the voltage and current changes of the rectifier, the DC bus capacitor, and the inverter.
[0013] Furthermore, a protective resistor is provided between the DC bus capacitor and the rectifier.
[0014] Furthermore, the energy storage elevator also includes an emergency module, which is connected to the energy conversion module and the control module. The emergency module automatically switches to battery energy storage module power supply when the power grid fails or the elevator malfunctions.
[0015] Furthermore, the energy storage elevator also includes an emergency module, which is connected to the energy conversion module and the control module. The emergency module automatically switches to battery energy storage module power supply when the power grid fails or the elevator malfunctions.
[0016] Furthermore, the preset threshold range is 50%-70% of the battery's full charge.
[0017] In summary, through the above-described configuration, the energy storage elevator of this invention does not require the battery's electrical energy to undergo a two-stage DC-DC-AC conversion before being input to the inverter's three-phase interface and then processed by a rectifier before being input to the DC bus capacitor. Instead, it employs a single-stage DC-DC conversion during energy transfer, and the direct connection to the inverter's DC bus capacitor further reduces energy loss. Similarly, during battery charging, the kinetic energy generated by the traction machine is also stored in the battery through a low-loss conversion method. More importantly, with this connection method, the input positions of the two power supply terminals are different. When the inverter's rectifier fails, causing the power grid to be unable to supply power, the battery module of this energy storage elevator can still directly provide power output to the traction machine through the DC bus capacitor, improving the system's safety and reliability.
[0018] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description
[0019] Figure 1 Here is a structural block diagram of an existing energy storage elevator;
[0020] Figure 2 A structural block diagram of an exemplary energy storage elevator provided by this utility model;
[0021] Figure 3 A structural block diagram of an existing frequency converter provided by this utility model;
[0022] Figure 4 This is a structural block diagram of an exemplary frequency converter in one embodiment of the present invention.
[0023] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings of the embodiments of this application. Detailed Implementation
[0024] Please see Figure 1 , Figure 1 The diagram shows the structural block of an existing energy storage elevator, which includes a battery energy storage module, an energy conversion module, an elevator body, and a control module. The elevator body includes a traction machine and a frequency converter. The control module monitors the status of the battery energy storage module and the elevator body to control the mode switching of the energy conversion module, enabling the conversion of the elevator's potential energy into electrical energy during charging, and controlling the battery energy storage module to supply power to the elevator body's traction machine through the energy conversion module during power supply. During the conversion process, the elevator body's frequency converter performs a two-stage AC / DC / AC conversion on the input current during charging, and converts the potential energy of the elevator during descent into electrical energy during discharging, which is then transferred to the energy conversion module.
[0025] The existing energy storage elevators and their associated frequency converters have problems with low conversion rates of potential energy to electrical energy during charging. Also, during discharging, if both the grid and the battery energy storage module are powered through the three-phase interface of the frequency converter, the elevator cannot operate normally if the rectifier fails, regardless of whether it is powered by the grid or the battery. Therefore, the existing energy storage elevators also have the problem of low emergency response capability.
[0026] To address the aforementioned problems with existing energy storage elevators, this utility model provides an energy storage elevator. Please refer to [link / reference]. Figure 2 It includes the elevator body, a DC-DC energy conversion module, a battery energy storage module, and a control module; the preferred battery energy storage module is an aqueous battery because aqueous batteries suffer minimal losses during charging and discharging, achieving energy conservation and emission reduction, and improving energy utilization efficiency. It also charges very quickly, reaching full charge in a short time. Suitable for elevator energy storage scenarios.
[0027] The elevator body includes the elevator itself, a traction machine, and a frequency converter. The traction machine, also known as the elevator main unit, is the elevator's power equipment, responsible for transmitting and distributing power to make the elevator run. It consists of a motor, brake, coupling, gearbox, traction sheave, frame, guide wheels, and an auxiliary handwheel. The frequency converter is a power control device that controls the AC motor by changing the frequency of the motor's power supply. It provides the required power voltage according to the motor's actual needs, thereby achieving energy saving and speed regulation.
[0028] Please see Figure 3 Existing energy storage elevators use frequency converters that include rectifiers, DC bus capacitors, discharge circuits, inverters, and fault detection circuits. During power supply, the frequency converter connects to an external three-phase power source through the rectifier's R, S, and T three-phase interfaces. The input AC power is converted to DC power after rectification. Due to power instability and load variations, the DC voltage fluctuates significantly, causing considerable interference and noise to the circuit, affecting its stability and performance. Therefore, DC capacitors are added to store charge and energy, smoothing the DC current, reducing noise and interference, and improving circuit stability and performance. Finally, an inverter composed of multiple IGBTs converts the DC power into a stable output AC power to supply the equipment. During the charging phase, the traction machine acts as a generator, and the generated current charges the DC bus capacitor from the inverter bridge. At this time, the DC bus capacitor voltage spikes. Therefore, conventional frequency converters require an additional discharge circuit connected in parallel with the DC bus capacitor. This discharge circuit includes a switch Vb and a braking resistor Rt connected in series with the switch. When the DC bus capacitor voltage spikes, the switch conducts, and the braking resistor Rt forms a circuit with the DC bus capacitor, discharging excess charge energy from the capacitor during the voltage spike to ensure safe charging. However, this energy is lost as heat, reducing the energy conversion rate.
[0029] In a preferred embodiment, to prevent the power supply from continuing to charge when it is already fully charged, which could cause the voltage of the DC bus capacitor to spike, the battery energy storage module includes a monitoring circuit. This monitoring circuit can determine the battery level and ensure that when the battery level exceeds a certain storage capacity (e.g., more than 50%), it can simultaneously supply power in parallel. This avoids stopping charging after the battery is fully charged, thus avoiding the problem of forced reliance on the braking resistor for heat loss. Parallel power supply also solves the problem of insufficient grid voltage during peak electricity consumption periods, which can lead to slower elevator speeds or elevator shutdowns.
[0030] After adding the monitoring circuit, the DC bus capacitor will no longer experience voltage spikes, therefore the discharge circuit can be omitted. Please refer to [link / reference needed]. Figure 4In another embodiment, the frequency converter includes a rectifier, a DC bus capacitor, an inverter, and a fault detection circuit.
[0031] The rectifier, the DC bus capacitor, and the inverter are connected in parallel. The fault detection circuit is connected to the rectifier, the DC bus capacitor, and the inverter respectively to detect the voltage and current changes of the rectifier, the DC bus capacitor, and the inverter.
[0032] By implementing the above settings, the original discharge circuit connected in parallel with the DC bus capacitor in the frequency converter is eliminated, simplifying the structure of the frequency converter and reducing system cost and losses.
[0033] In a preferred embodiment, a protective resistor R0 is further provided between the rectifier and the DC bus capacitor to prevent the DC bus capacitor from breaking down the diode in the rectifier during the charging process.
[0034] One end of the DC-DC energy conversion module is connected to the battery energy storage module, and the other end is connected to both ends of the DC bus capacitor of the frequency converter. The DC-DC energy conversion module is used to realize the conversion between elevator potential energy and electrical energy, and the energy conversion between the battery energy storage module and the elevator.
[0035] When powering the elevator, the battery energy storage module converts the chemical energy into direct current (DC) for output. The DC-DC energy conversion module then transfers this electrical energy to the DC bus capacitor of the frequency converter, powering the frequency converter. At this time, the DC bus capacitor charges, acting as a power source for the inverter. The inverter's switching mechanism provides a stable AC output, driving the traction machine and supplying power to the elevator. As the elevator descends, its potential energy decreases. The traction machine, through a feedback mode, converts kinetic energy into electrical energy and stores this energy in the DC bus capacitor. The DC bus capacitor then transfers this energy through the DC-DC energy conversion module, recovering and storing the electrical energy in the battery energy storage module.
[0036] The control module is used to obtain the status of the elevator body and the battery energy storage module and switch the status of the DC-DC energy conversion module.
[0037] The control module monitors the elevator's operating status, the battery storage module's status, and the power grid's power supply status, and performs scheduling and control based on actual conditions. This module acquires the elevator's motion status (including upward movement, downward movement, and stationary position). When the elevator's potential energy does positive work (e.g., the elevator is moving upward), the generated energy is converted into electrical energy and stored. When the elevator's potential energy does negative work (e.g., the elevator is moving downward), the stored electrical energy is released first. When the battery is fully charged and the elevator is ascending, power is supplied synchronously from the power grid and battery to achieve energy conservation.
[0038] With the above configuration, the energy storage elevator of this invention does not require the battery's electrical energy to undergo a two-stage DC-DC-AC conversion before being input to the inverter's three-phase interface and then processed by a rectifier before being input to the DC bus capacitor. Instead, it uses a single-stage DC-DC conversion during energy transfer, and directly connecting to the inverter's DC bus capacitor further reduces energy loss. Similarly, during battery charging, the kinetic energy generated by the traction machine is also stored in the battery through a low-loss conversion method. More importantly, with this connection method, the input positions of the two power supply terminals are different. When the inverter's rectifier fails, causing the power grid to be unable to supply power, the battery module of this invention can still directly provide power output to the traction machine through the DC bus capacitor, improving the system's safety and reliability.
[0039] In another preferred embodiment, the energy storage elevator further includes an emergency module connected to the energy conversion module and the control module. The emergency module automatically switches to battery energy storage module power supply in the event of a power outage or elevator malfunction, thus improving system safety.
[0040] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.
Claims
1. An energy storage elevator, characterized in that, include: Elevator body, DC-DC energy conversion module, battery energy storage module, and control module; The elevator body includes an elevator, a traction machine, and a frequency converter; One end of the DC-DC energy conversion module is connected to the battery energy storage module, and the other end is connected to the DC bus capacitor of the frequency converter. The DC-DC energy conversion module is used to realize the conversion between elevator potential energy and electrical energy, and the energy conversion between the battery energy storage module and the elevator. The control module is used to obtain the status of the elevator body and the battery energy storage module and switch the status of the DC-DC energy conversion module.
2. The energy storage elevator according to claim 1, characterized in that: The battery energy storage module includes a monitoring circuit, which is connected to the control module. The monitoring circuit is used to detect whether the battery power exceeds a preset threshold. If it does, it sends a power supply signal to the control module.
3. The energy storage elevator according to claim 2, characterized in that: The frequency converter includes a rectifier, a DC bus capacitor, an inverter, and a fault detection circuit. The rectifier, the DC bus capacitor, and the inverter are connected in parallel. The fault detection circuit is connected to the rectifier, the DC bus capacitor, and the inverter respectively to detect the voltage and current changes of the rectifier, the DC bus capacitor, and the inverter.
4. The energy storage elevator according to claim 3, characterized in that: A protective resistor is also provided between the DC bus capacitor and the rectifier.
5. An energy storage elevator according to claim 4, characterized in that: The energy storage elevator also includes an emergency module, which is connected to the energy conversion module and the control module. The emergency module automatically switches to the battery energy storage module for power supply when the power grid fails or the elevator malfunctions.
6. An energy storage elevator according to any one of claims 2-5, characterized in that: The preset threshold range is 50%-70% of the battery's full charge.