Feedback-based elevator potential energy recovery system

Abstract

The invention relates to the technical field of elevator potential energy recovery, in particular to a feedback type-based elevator potential energy recovery system, which comprises a data acquisition module, a feedback module and a control module, the clustering module is used for clustering the operation parameters based on the conversion electric quantity so as to obtain various operation parameters generating the same conversion electric quantity; the control module comprises a contactor control unit used for determining whether to close a contactor based on the converted electric quantity; the voltage monitoring unit is used for monitoring the voltage of the direct-current bus in real time to determine whether the voltage is suddenly changed or not, so that a preset electric quantity threshold value is increased based on the voltage suddenly-changing duration, or a recovery current conveying area is adjusted based on the voltage fluctuation amplitude; the temperature monitoring unit is used for monitoring the resistance temperature of the brake resistor in real time so as to reduce the preset electric quantity threshold value based on the single overheating duration; and a calling unit. The electric quantity recovery efficiency of the elevator potential energy recovery system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator potential energy recovery, and particularly to a feedback-based elevator potential energy recovery system. Background Art

[0002] With the acceleration of the urbanization process, elevators have become an indispensable vertical transportation tool in modern buildings. However, during the operation of an elevator, especially when it is fully loaded and descending or ascending empty, the traction machine will generate a large amount of regenerative electric energy due to potential energy conversion. In traditional elevator systems, this part of the electric energy is often consumed by braking resistors in the form of heat, which not only causes a great waste of energy but also leads to an unnecessary increase in the ambient temperature.

[0003] To solve this problem, an elevator potential energy recovery system has emerged. Through advanced inverter technology, this system can detect the operating state of the elevator in real time, accurately capture and collect the excess electric energy generated by the traction machine, and convert this electric energy into high-quality alternating current and directly feedback it to the elevator operating system for other electrical equipment to use. Although this process realizes the effective recycling of energy, reduces the overall energy consumption of the elevator, and reduces the burden on the environment, the conversion of excess electric energy from potential energy into alternating current will cause power loss, and improper starting timing of the elevator potential energy recovery system will result in low power recovery efficiency.

[0004] Chinese Patent Publication No.: CN116961201 B discloses an external elevator potential energy recovery system and method. The potential energy recovery device includes a mechanical and electrical recovery device connected to the elevator traction machine. The mechanical and electrical recovery device transports the recovered electric energy to the common power supply DC bus through an inverter. The recovered electric energy on the common power supply DC bus is connected to a super capacitor through a DC / DC converter. The super capacitor is connected to a power supply switching device through a controller. One end of the power supply switching device is connected to the common power supply, and the other end is connected to a recovered power consumption device; overall, the maximum utilization of the recovered electric energy is implemented according to a remote monitoring processor, and the recovered electric energy is optimally allocated and used according to the daily storage capacity of the super capacitor and the specific usage situation of the elevator, avoiding the traditional drawbacks and defects of excessive electric energy that cannot be recovered, effectively improving the turnover and utilization efficiency of the recovered electric energy, and achieving the effect of energy conservation and environmental protection.

[0005] There are still the following problems in the prior art: In the prior art, there is a lack of monitoring of the starting timing of the potential energy recovery system. When the excess electric energy generated by the elevator is small, the alternating current generated by the recovery and inversion does not have practical value, resulting in low power recovery efficiency of the potential energy recovery system. Summary of the Invention

[0006] To this end, the present invention provides a feedback-based elevator potential energy recovery system to overcome the problem in the prior art that the lack of monitoring of the opening time of the potential energy recovery system results in low power recovery efficiency of the potential energy recovery system.

[0007] To achieve the above object, the present invention provides a feedback-based elevator potential energy recovery system, including:

[0008] A data acquisition module, which is used to obtain several operating parameters of the elevator, the converted power corresponding to each operating parameter of the elevator, and the recovered power of the potential energy recovery device. Among them, the operating parameters include the operating height difference and the car weight of the elevator;

[0009] A clustering module, which is connected to the data acquisition module and is used to cluster the operating parameters based on the converted power to obtain various theoretical operating parameters corresponding to the same converted power;

[0010] A control module, which is connected to the data processing module, including:

[0011] A contactor control unit, which is used to determine whether to close the contactor based on the converted power;

[0012] A voltage monitoring unit, which is used to monitor the voltage of the DC bus in real time and whether the voltage changes suddenly, so as to increase the preset power threshold based on the voltage mutation duration, or adjust the recovered current transmission area based on the voltage fluctuation amplitude;

[0013] A temperature monitoring unit, which is used to monitor the resistance temperature of the braking resistor in real time to reduce the preset power threshold based on the single overheat duration;

[0014] A calling unit, which calls the voltage monitoring unit in response to the condition of closing the contactor, or calls the temperature monitoring unit in response to the condition of not closing the contactor.

[0015] Further, the clustering module determines several converted powers within the preset power range as the same converted power based on the preset power range, classifies several operating parameters corresponding to the same converted power into one category to generate several data sets, and determines several operating parameters within any one of the data sets as several theoretical operating parameters.

[0016] Further, the condition for the contactor control unit to determine to close the contactor is that the converted power exceeds the preset power threshold.

[0017] Further, the condition for the contactor control unit not to close the contactor is that the converted power is less than or equal to the preset power threshold.

[0018] Further, under the condition of closing the contactor, the voltage monitoring unit monitors the voltage of the DC bus in real time, determines that the voltage has mutated and determines the voltage mutation duration based on the comparison result that the voltage is less than the first preset voltage;

[0019] The voltage monitoring unit determines to increase the preset power threshold based on the comparison result that the voltage mutation duration is greater than or equal to the first preset duration, wherein the increase amplitude of the preset power threshold is determined according to the difference between the voltage mutation duration and the first preset duration.

[0020] Further, under the condition of determining to increase the preset power threshold, the voltage monitoring unit determines the current actual operating parameters and several theoretical operating parameters corresponding to the current converted power, fits the actual operating parameters with the theoretical operating parameters, and corrects the theoretical operating parameters based on the fitting result.

[0021] Further, the voltage monitoring unit determines that the voltage has mutated and determines the voltage fluctuation amplitude based on the comparison result that the voltage is greater than the second preset voltage;

[0022] The voltage monitoring unit determines to increase the recovery current transmission area based on the comparison result that the voltage fluctuation amplitude is greater than or equal to the preset amplitude. A transmission area range of the recovery current is preset in advance, and the increase amplitude of the recovery current transmission area is determined according to the difference between the voltage fluctuation amplitude and the preset amplitude.

[0023] Further, under the condition of not closing the contactor, the temperature monitoring unit monitors the resistance temperature of the braking resistor in real time, determines the resistance temperature as a single abnormal resistance temperature based on the comparison result that the resistance temperature is greater than the preset temperature, and determines the single overheat duration of the single abnormal resistance temperature.

[0024] Further, the temperature monitoring unit calculates the heat generation power based on the comparison result that the single overheat duration is greater than the second preset duration.

[0025] Further, the temperature monitoring unit reduces the preset power threshold based on the heat generation power, wherein the reduction amplitude of the preset power threshold is determined according to the heat generation power and the power conversion rate, and the power conversion rate is the ratio of the recovered power to the corresponding converted power.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows. The present invention determines whether to close the contactor by the converted power. Closing the contactor means starting the potential energy recovery system. During the operation of the elevator, the potential energy is converted into direct current. The potential energy recovery system recovers and inversely converts the direct current into alternating current. There will be some losses during the inversion process. Under the condition that the alternating current generated after the inversion of the direct current generated by the potential energy is extremely small and cannot be utilized, the potential energy recovery system does work but does not generate value, resulting in low recovery efficiency. Therefore, determining whether to start the potential energy recovery system according to the converted power can effectively improve the recovery efficiency of the potential energy recovery system; when it is determined to start the potential energy recovery system, the voltage of the DC bus is monitored. The magnitude of the voltage of the DC bus represents the amount of converted power. According to the voltage of the DC bus, it is determined that the converted power suddenly increases or suddenly decreases. In response to the sudden increase in the converted power, the number of current transmission area is increased according to the change amplitude of the voltage to prevent the voltage of the DC bus from surging. In response to the sudden decrease in the converted power, the starting threshold of the potential energy recovery system is increased according to the duration of the voltage decrease, so as to achieve the purpose of timely closing the potential energy recovery system to prevent the voltage of the DC bus from dropping suddenly; when it is determined not to start the potential energy recovery system, the power converted from the potential energy of the elevator is consumed by the braking resistor heating. Therefore, it is necessary to monitor the resistance temperature of the braking resistor. The higher the resistance temperature and the longer the duration, the greater the converted power. The potential energy recovery system can be started for energy recovery, thereby reducing the starting threshold of the potential energy recovery system and timely turning on the potential energy recovery system to prevent excessive energy waste. Through the precise control of the potential energy recovery system, effective energy recovery is achieved, thereby improving the power recovery efficiency of the potential energy recovery system.

[0027] Furthermore, the present invention clusters the operating parameters of the elevator corresponding to the generation of the same converted power through the data collected by the data acquisition module, providing an accurate basis for the potential energy recovery system to pre-determine the upcoming converted power according to the actual operating parameters of the elevator, so as to make an accurate determination of whether to start the potential energy recovery system. As the operating time of the elevator increases, problems such as aging of the elevator will occur, and the converted power and the corresponding theoretical operating parameters will change. The present invention corrects the theoretical operating parameters in real time according to the actual operating parameters based on the power recovery situation of the potential energy recovery system, thereby further improving the control accuracy of the potential energy recovery system and further improving the power recovery efficiency of the potential energy recovery system.

[0028] Furthermore, in the case where the actual converted power generated from the operating parameters of the elevator does not match the converted power corresponding to the operating parameters, the present invention determines the data set corresponding to the actual converted power, fits the actual operating parameters with the theoretical operating parameters in the data set, and converts the potential energy offset caused by, for example, excessive wind force into an impact on the weight. Since the calculation of potential energy is the product of height and weight, under the condition of a certain height, the resistance can be converted into an impact on the weight and this impact is added to the data set, providing more accurate data for the potential energy recovery system to pre-determine the converted power according to the actual operating parameters of the elevator, thereby further improving the control accuracy of the potential energy recovery system and further enhancing the power recovery efficiency of the potential energy recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural block diagram of a feedback-based elevator potential energy recovery system according to an embodiment of the present invention;

[0030] Figure 2 is a flowchart for determining whether to close a contactor according to an embodiment of the present invention;

[0031] Figure 3 is a flowchart for determining whether to increase a preset power threshold according to an embodiment of the present invention;

[0032] Figure 4 is a flowchart for determining whether to increase the recovery current transmission area according to an embodiment of the present invention;

[0033] Figure 5 is a wiring schematic diagram of the main circuit of the elevator potential energy recovery system and the elevator control cabinet according to an embodiment of the present invention;

[0034] In the figure: 1, the main circuit line of the elevator control cabinet; 2, the line of the elevator potential energy recovery system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to make the objectives and advantages of the present invention clearer and more understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0037] It should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0038] Please refer to Figures 1-4 as shown in Figure 1 the structural block diagram of the feedback-based elevator potential energy recovery system according to an embodiment of the present invention; Figure 2 the flowchart for determining whether to close the contactor according to an embodiment of the present invention; Figure 3 the flowchart for determining whether to increase the preset power threshold according to an embodiment of the present invention; Figure 4 the flowchart for determining whether to increase the recovery current transmission area according to an embodiment of the present invention.

[0039] An embodiment of the present invention provides a feedback-based elevator potential energy recovery system, including:

[0040] A data acquisition module, which is used to obtain several operating parameters of the elevator, the converted power corresponding to each operating parameter of the elevator, and the recovered power of the potential energy recovery device. Among them, the operating parameters include the operating height difference and the car weight of the elevator;

[0041] A clustering module, which is connected to the data acquisition module and is used to cluster the operating parameters based on the converted power to obtain various theoretical operating parameters corresponding to the same converted power;

[0042] A control module, which is connected to the data processing module, and includes,

[0043] A contactor control unit, which is used to determine whether to close the contactor based on the converted power;

[0044] A voltage monitoring unit, which is used to monitor the voltage of the DC bus and whether the voltage changes suddenly in real time, so as to increase the preset power threshold based on the voltage mutation duration, or adjust the recovery current transmission area based on the voltage fluctuation amplitude;

[0045] A temperature monitoring unit, which is used to monitor the resistance temperature of the braking resistor in real time to reduce the preset power threshold based on the single overheat duration;

[0046] An invocation unit, which invokes the voltage monitoring unit in response to the condition of closing the contactor, or invokes the temperature monitoring unit in response to the condition of not closing the contactor.

[0047] In the embodiments of the present invention, when the elevator is ascending with no load or light load (i.e., the weight of the car is less than the elevator counterweight) and descending with full load or heavy load (i.e., the weight of the car is greater than the elevator counterweight), the traction machine operates in the power generation state. The generated electric energy is converted into DC electric energy on the DC bus of the frequency converter through the motor and the frequency converter, and is temporarily stored in the large capacitor in the DC circuit of the frequency converter. The intuitive manifestation of the amount of electricity in the large capacitor is the magnitude of the DC bus voltage. The elevator potential energy recovery system converts the DC electric energy stored in the large capacitor on the DC side of the elevator frequency converter into alternating current and sends it back to the elevator operation system.

[0048] Specifically, the greater the potential energy of the elevator, the more electric energy is converted. The potential energy of the elevator is positively correlated with the descending height of the heavier end of the elevator car and the elevator counterweight. It can be understood that with different operating parameters of the elevator, the potential energy change may not be different, and thus the converted electric energy generated may not be different. Therefore, the operating parameters of the elevator can be clustered according to the value of the converted electric energy, and the operating parameters that generate the same converted electric energy are grouped into one category, and each category of operating parameters forms a data set.

[0049] Specifically, the operating parameters of the elevator are obtained from the elevator control system, and the converted electric energy and the recovered electric energy are measured by an electric meter set at the corresponding position. The model and parameters of the electric meter are not limited.

[0050] Specifically, the clustering module determines a number of converted electric energies within the preset electric energy range as equal converted electric energies based on the preset electric energy range, groups the number of operating parameters corresponding to the equal converted electric energies into one category to generate a number of data sets, and determines the number of operating parameters within any one of the data sets as a number of theoretical operating parameters, where the preset electric energy range is greater than or equal to the first electric energy and less than or equal to the second electric energy.

[0051] It can be understood that the generated electric energies with the absolute difference in the generated electric energy within the preset electric energy range are determined as equal converted electric energies. For example, the DC electric energies generated by several operations of a single elevator are statistically counted as 10 Coulombs, 9.8 Coulombs, 8 Coulombs, 5 Coulombs, 10.2 Coulombs, 4.7 Coulombs, and 4.9 Coulombs. Then 10 Coulombs, 9.8 Coulombs, and 10.2 Coulombs are equal converted electric energies, and 5 Coulombs, 4.7 Coulombs, and 4.9 Coulombs are equal converted electric energies.

[0052] It can be understood that the difference in the recovered electric energy generated after the loss in the inversion process of the converted electric energy within the preset electric energy range can be ignored.

[0053] Specifically, the first electric energy is 0 Coulombs; the value range of the second electric energy is set to [0.15 Coulombs, 0.4 Coulombs], and 0.3 Coulombs is preferably selected in the embodiments of the present invention.

[0054] Specifically, the contactor control unit determines that the condition for closing the contactor is satisfied when the converted power exceeds a preset power threshold.

[0055] Specifically, the condition for the contactor control unit not to close the contactor is satisfied when the converted power is less than or equal to the preset power threshold.

[0056] Specifically, the value range of the preset power threshold is set to [3 Coulombs, 10 Coulombs], and 5 Coulombs is preferably selected in the embodiments of the present invention.

[0057] Specifically, in order to improve the recovery efficiency of the potential energy recovery system, when it is determined that the recovered power converted from the converted power is not sufficient to be utilized, the contactor is not closed, so that the potential energy recovery system is not started.

[0058] Specifically, under the condition of closing the contactor, the voltage monitoring unit monitors the voltage of the DC bus in real time, and determines that the voltage has a sudden change and determines the duration of the voltage sudden change based on the comparison result that the voltage is less than the first preset voltage;

[0059] Based on the comparison result that the voltage is greater than the second preset voltage, it is determined that the voltage has a sudden change and the voltage fluctuation amplitude is determined.

[0060] It can be understood that closing the contactor also means starting the potential energy recovery system. Under normal operating conditions, the magnitude of the DC bus voltage reflects the energy flow in the elevator system. When the traction machine is in the electric state, the electric energy on the DC bus is consumed and the voltage decreases. When the traction machine is in the generating state, the electric energy is fed back to the DC bus and the voltage increases. On the premise that the potential energy recovery system predicts the converted power according to the operating parameters of the elevator, the switch of the potential energy recovery system is accurately controlled, so that the voltage of the DC bus maintains a dynamic balance and fluctuates within a small range.

[0061] It can be understood that too large a voltage of the DC bus will cause problems such as unstable operation of the motor and damage to the frequency converter, and too low a voltage of the DC bus will cause problems such as motor overload. Therefore, the voltage of the DC bus needs to be maintained within a certain range.

[0062] Specifically, the value of the first preset voltage is determined according to the minimum value of the allowable voltage of the DC bus. For example, it is 1.2 times the minimum value of the allowable voltage. The value of the second preset voltage is determined according to the maximum value of the allowable voltage of the DC bus. For example, it is 0.8 times the maximum value of the allowable voltage.

[0063] Specifically, the duration of the voltage sudden change is the duration of the situation where the voltage is less than the first preset voltage, and the voltage fluctuation amplitude is the difference between the voltage and the second preset voltage.

[0064] Specifically, the voltage monitoring unit determines to increase the preset power threshold based on a comparison result that the voltage mutation duration is greater than or equal to a first preset duration, wherein the increase amplitude of the preset power threshold is determined according to the difference between the voltage mutation duration and the first preset duration;

[0065] Based on a comparison result that the voltage mutation duration is less than the first preset duration, it is determined that the preset power threshold remains unchanged.

[0066] Specifically, the setting of the first preset duration is determined according to a first preset voltage. For example, when the first preset voltage is 1.2 times the minimum allowable voltage, the first preset duration is to calculate the power in the capacitor connected to the DC bus according to 0.2 times the minimum allowable voltage. The power Q = C×V, where C is the capacitance value of the capacitor and V is the voltage of the DC bus. At the same time, Q = I×t, where I is the current and t is the duration. The ratio of the power Q to the recovery current I is the duration for the elevator potential energy recovery system to output the recovered power while ensuring the safety of the DC bus voltage without inputting power to the capacitor connected to the DC bus. It can be understood that the first preset duration is less than this duration. For example, the first preset duration can be set to 0.6 times this duration.

[0067] Specifically, the calculation method for the increase amplitude of the preset power threshold is as follows: The difference between the voltage mutation duration and the first preset duration is determined as the time difference, and the product of the time difference and the recovery current is the increase amplitude of the preset power threshold.

[0068] Specifically, under the condition that the voltage monitoring unit determines to increase the preset power threshold, it determines the current actual operating parameters and several theoretical operating parameters corresponding to the current converted power, fits the actual operating parameters with the theoretical operating parameters, and corrects the theoretical operating parameters based on the fitting result.

[0069] It can be understood that there will be a large resistance in the elevator shaft during strong wind weather, which will reduce the conversion rate of potential energy into electrical energy. The conversion power corresponding to the operating parameters of the elevator without considering wind resistance is the ideal conversion power. However, in fact, the existence of wind resistance makes the actual conversion power less than the ideal conversion power. The potential energy recovery system can determine the corresponding data set according to the actual conversion power, match the actual operating parameters with the data in the data set, find the parameters with the same running height difference, convert the influence of wind resistance into the influence on weight, and thus add the influence of wind resistance to the operating parameters to correct the data in the data set, thereby improving the determination accuracy of the potential energy recovery device for the converted power. It can be understood that the ideal conversion power is the conversion power corresponding to the ideal operating parameters.

[0070] Meanwhile, as the operation time of the elevator increases, the elevator will age, and the relationship between the operation parameters and the converted power will change. The ideal operation parameters are corrected based on the comparison between the actual converted power and the ideal converted power, so as to further improve the estimation of the converted power and the recovered power according to the parameters during the elevator operation.

[0071] Specifically, the voltage monitoring unit determines to increase the recovered current transmission area based on the comparison result that the voltage fluctuation amplitude is greater than or equal to the preset amplitude. Among them, the range of the recovered current transmission area is preset, and the increase amplitude of the recovered current transmission area is determined according to the difference between the voltage fluctuation amplitude and the preset amplitude;

[0072] Based on the comparison result that the voltage fluctuation amplitude is less than the preset amplitude, it is determined not to increase the recovered current transmission area.

[0073] Specifically, the potential energy recovery system preferentially delivers the recovered power to the elevator operation system. Under the condition that there is still surplus recovered power, it can supply areas in the elevator such as the lighting system and the monitoring system, and determine the voltage of each area respectively.

[0074] Specifically, the setting of the preset amplitude is determined according to the second preset voltage. For example, when it is determined that the second preset voltage is 0.8 times the maximum allowable voltage, the setting of the preset amplitude is less than the difference between the maximum allowable voltage and the second preset voltage. For example, it can be set to 0.1 times the difference.

[0075] Specifically, the method for determining the increase amplitude of the recovered current transmission area is as follows: determine the difference between the voltage fluctuation amplitude and the preset amplitude, sum up the voltages of each area except the original transmission area according to different numbers of areas, and take the sum result equal to the difference as the standard. The corresponding number of areas minus the number of the original transmission area is the increase amplitude.

[0076] Specifically, under the condition of not closing the contactor, the temperature monitoring unit monitors the resistance temperature of the braking resistor in real time, and determines the resistance temperature as the single - time abnormal resistance temperature based on the comparison result that the resistance temperature is greater than the preset temperature, and determines the single - time overheat duration of the single - time abnormal resistance temperature.

[0077] Specifically, under the condition of not closing the contactor, the excess converted power will be consumed by the heat generated by the braking resistor. However, due to the limited converted power, the heating temperature of the braking resistor will not be too high.

[0078] Specifically, the value range of the preset temperature is set to [30°C, 50°C], and the preferred value in the embodiments of the present invention is 40°C.

[0079] It can be understood that the higher the temperature of the braking resistor and the longer the duration, the more power is consumed.

[0080] Specifically, the temperature monitoring unit calculates the generated heat power based on the comparison result that the single overheat duration is greater than a second preset duration.

[0081] Specifically, the second preset duration is the ratio of a preset power threshold to the current of the braking resistor.

[0082] Specifically, the temperature monitoring unit reduces the preset power threshold based on the generated heat power, wherein the reduction amplitude of the preset power threshold is determined according to the generated heat power and the power conversion rate, and the power conversion rate is the ratio of the recovered power to the corresponding converted power.

[0083] Specifically, the generated heat power is the product of the current flowing through the braking resistor and the flowing time, and the product of the generated heat power and the conversion rate is the reduction amplitude of the preset power threshold.

[0084] Specifically, the value range of the power conversion rate is set to [80%, 98%], and 90% is preferably selected in the embodiments of the present invention.

[0085] Embodiment

[0086] Taking the operation process of a single elevator as an example: the rated load of the elevator is 1000 kg, the counterweight mass is 1000 kg, the DC bus capacitor capacity is 2000 μF, and the maximum voltage is 600 V;

[0087] No-load upward (power generation state), that is, the car weight is 0 kg, the counterweight weight is 1000 kg, and it travels upward 30 m. The potential energy E = (m 配重 -m 轿厢 ) × g × h = (1000 - 0) × 9.8 × 30 = 294000 J;

[0088] The initial voltage of the DC bus is 470 V, and it is 500 V after the elevator operation ends. The converted power Q 转化 = C × (V 终 -V 始 ) = 2000 × (500 - 470) ÷ 1000 = 60 C, which is greater than 5 coulombs. The contactor is closed to start the potential energy recovery system. The converted power is inverted to generate the recovered power, Q 回收 = 60 × 90% = 54 C;

[0089] At the same time, the DC bus voltage of 500 V is greater than the second preset voltage of 0.8 × 600 = 480 V, it is determined that a mutation occurs, and the voltage fluctuation amplitude is 500 - 480 = 20 V, which is greater than the preset amplitude of (600 - 480) × 0.1 = 12 V. It is determined to increase the transmission area of the recovered current.

[0090] The load is 800 kg when descending (in the power generation state), that is, the car weight is 800 kg, the counterweight weight is 1000 kg, and it descends 30 m. The potential energy E = (m 配重 - m 轿厢 ) × g × h = (1000 - 800) × 9.8 × 30 = 58800 J;

[0091] The voltage of the DC bus is initially 510 V and becomes 512 V after the elevator operation ends. The converted charge Q 转化 = C × (V 终 - V 始 ) = 2000 × (512 - 510) ÷ 1000 = 4 C, which is less than 5 Coulombs. The contactor is not closed, and the converted charge is dissipated as heat through the braking resistor. The temperature of the braking resistor is monitored to be 38 °C, which is less than the preset temperature of 40 °C, so no further monitoring of the braking resistor is performed.

[0092] Please refer to Figure 5 as shown, which is the wiring schematic diagram of the main circuit of the elevator potential energy recovery system and the elevator control cabinet in the embodiment of the present invention.

[0093] The elevator control cabinet delivers the direct current generated during the elevator operation to the elevator potential energy recovery system, and the elevator potential energy recovery system converts the direct current into alternating current and delivers it to the power grid for utilization, thus achieving the purpose of potential energy recovery and utilization.

[0094] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A feedback-based elevator potential energy recovery system, characterized in that: include: A data acquisition module, which is used to obtain several operating parameters of the elevator, the converted electricity corresponding to each operating parameter of the elevator and the recovered electricity of the potential energy recovery device, wherein the operating parameters include the operating height difference of the elevator and the weight of the car; A clustering module, connected to the data acquisition module, for clustering the operating parameters based on the converted electricity to obtain various theoretical operating parameters corresponding to the same converted electricity; A control module, connected to the data processing module, comprising: A contactor control unit, which is used to determine whether to close the contactor based on a comparison result between the converted electric quantity and a preset electric quantity threshold; A voltage monitoring unit, which is used to monitor the voltage of the DC bus in real time and whether the voltage has a sudden change, so as to increase the preset power threshold based on the duration of the voltage sudden change, or adjust the recovery current transmission area based on the voltage fluctuation amplitude; A temperature monitoring unit, which is used to monitor the resistance temperature of the brake resistor in real time to reduce the preset power threshold based on the duration of a single overheating; A calling unit is configured to call the voltage monitoring unit in response to a condition of closing the contactor, or to call the temperature monitoring unit in response to a condition of not closing the contactor.

2. The feedback-based elevator potential energy recovery system according to claim 1, characterized in that: The clustering module determines several conversion electric quantities within the preset electric quantity range as equal conversion electric quantities based on the preset electric quantity range, classifies several operating parameters corresponding to the equal conversion electric quantities into one category to generate several data sets, and determines several operating parameters in any of the data sets as several theoretical operating parameters.

3. The feedback-based elevator potential energy recovery system according to claim 2, characterized in that: The contactor control unit determines that a condition for closing the contactor is satisfied when the converted power exceeds a preset power threshold.

4. The feedback-based elevator potential energy recovery system according to claim 2, characterized in that: The condition for the contactor control unit not closing the contactor is that the converted electric quantity is less than or equal to a preset electric quantity threshold.

5. The feedback-based elevator potential energy recovery system according to claim 3, characterized in that: The voltage monitoring unit monitors the voltage of the DC bus in real time under the condition of closing the contactor, and determines that the voltage has suddenly changed and determines the duration of the voltage suddenly change based on a comparison result that the voltage is less than a first preset voltage; The voltage monitoring unit determines to increase the preset power threshold based on a comparison result that the voltage mutation duration is greater than or equal to a first preset duration, wherein the increase amplitude of the preset power threshold is determined according to the difference between the voltage mutation duration and the first preset duration.

6. The feedback-based elevator potential energy recovery system according to claim 5, characterized in that: Under the condition of increasing the preset power threshold, the voltage monitoring unit determines the current actual operating parameters and several theoretical operating parameters corresponding to the current conversion power, fits the actual operating parameters with the theoretical operating parameters, and modifies the theoretical operating parameters based on the fitting results.

7. The feedback-based elevator potential energy recovery system according to claim 5, characterized in that: The voltage monitoring unit determines that the voltage has a sudden change and determines the voltage fluctuation amplitude based on a comparison result that the voltage is greater than a second preset voltage; The voltage monitoring unit determines to increase the recovery current delivery area based on the comparison result that the voltage fluctuation amplitude is greater than or equal to the preset amplitude, wherein a delivery area range of the recovery current is pre-set, and the increase amplitude of the recovery current delivery area is determined according to the difference between the voltage fluctuation amplitude and the preset amplitude.

8. The feedback-based elevator potential energy recovery system according to claim 4, characterized in that: The temperature monitoring unit monitors the resistance temperature of the brake resistor in real time without closing the contactor, determines the resistance temperature as a single abnormal resistance temperature based on a comparison result that the resistance temperature is greater than a preset temperature, and determines a single overheating duration of the single abnormal resistance temperature.

9. The feedback-based elevator potential energy recovery system according to claim 8, characterized in that: The temperature monitoring unit calculates the heat generation power based on a comparison result that the single overheating duration is greater than a second preset duration.

10. The feedback-based elevator potential energy recovery system according to claim 9, characterized in that: The temperature monitoring unit reduces the preset power threshold based on the heat generation power, wherein the reduction range of the preset power threshold is determined according to the heat generation power and the power conversion rate, and the power conversion rate is the ratio of the recovered power to the corresponding converted power.

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