Energy-saving method for elevator

Abstract

The invention discloses an elevator energy-saving method. The elevator energy-saving method comprises the following steps that an elevator energy-saving system is built on cluster elevators; monitoring voltage values of the high-voltage direct-current bus and the energy storage low-voltage bus; setting a voltage working threshold value of the high-voltage direct-current bus and a voltage protection threshold value of the energy storage low-voltage bus; regulating and controlling electric energy transmission according to the voltage value and the voltage threshold value of the energy storage low-voltage bus; and an energy storage device SOC threshold value is set, and the energy storage device SOC and the power generation state are regulated and controlled. According to the technical scheme, potential energy of the cluster elevator is fully recycled, renewable energy sources are utilized, the charging state of the high-power nickel-metal hydride battery is adjusted and controlled in real time, intelligent electric energy management of the cluster elevator, photovoltaic power generation, wind power generation and an emergency system is achieved, meanwhile, mutual interference among the multiple elevators is reduced, the system is suitable for elevator groups of different scales and types, and the cost is reduced. And expansion and upgrading are facilitated.

Description

Technical Field

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

[0002] As the height and size of modern buildings continue to increase, elevators have become an indispensable means of vertical transportation in daily life. The energy consumption of elevators has attracted widespread attention. Traditional elevator systems rely on mains power supply, and the energy utilization efficiency needs to be improved. Especially when the elevator group is in operation, energy efficiency optimization is particularly important. On the other hand, with the development of renewable energy technology, introducing renewable energy into the elevator system and optimizing the use of electric energy using energy storage devices is an effective way to improve the energy efficiency of the elevator system.

[0003] At present, lead-acid batteries and supercapacitors are the main solutions for elevator energy storage. However, lead-acid batteries have low rate performance and cannot efficiently recover the potential energy generated by the elevator during rapid descent, especially under high load conditions. Their energy release capacity is insufficient, limiting the energy recovery efficiency of the elevator. Although supercapacitors have fast charging and discharging characteristics, their relatively low energy density makes it difficult for them to provide sufficient energy support during long-term operation, especially in scenarios where cluster elevators are interconnected or connected to other renewable energy sources, and it is impossible to achieve large-scale potential energy recovery and clean electricity utilization.

[0004] Chinese patent document CN101531299A discloses an "intelligent energy-saving device for elevator groups". It uses a rectifier module, two DC bus bars, and n single elevator control components; the three power input terminals of the rectifier module are connected to the AC power grid, and the positive phase voltage output terminal and the negative phase voltage output terminal of the rectifier module are respectively connected to the corresponding DC bus bars; n single elevator control components are respectively connected in parallel between the two DC bus bars; it also includes a DC energy storage component, which is connected in parallel between the DC bus bars. It stores and releases energy in the power generation state and the electric state through the DC energy storage component, and supplies it to the elevator group. The compatibility of the above technical solutions is difficult to effectively promote. Summary of the invention

[0005] The present invention mainly solves the technical problem that the compatibility of the original technical solution is difficult to effectively promote, and provides an elevator energy-saving method, which fully recovers the potential energy of cluster elevators and utilizes renewable energy, adjusts and controls the charging state of high-power nickel-hydrogen batteries in real time, and realizes intelligent power management of cluster elevators, photovoltaic power generation, wind power generation and emergency systems. At the same time, it reduces the mutual interference between multiple elevators, adapts to elevator groups of different sizes and types, and is easy to expand and upgrade.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: The present invention comprises the following steps: S1 constructing an elevator energy-saving system on a cluster elevator; S2 monitors the voltage values ​​of the high-voltage DC bus and the energy storage low-voltage bus; S3 sets the voltage operating threshold of the high-voltage DC bus and the voltage protection threshold of the energy storage low-voltage bus; S4 regulates the power transmission according to the voltage value of the energy storage low-voltage bus and its voltage threshold; S5 sets the SOC threshold of the energy storage device and regulates the SOC and power generation status of the energy storage device.

[0007] It fully recycles the potential energy of cluster elevators and utilizes renewable energy, adjusts and controls the charging status of high-power nickel-hydrogen batteries in real time, and realizes intelligent power management of cluster elevators, photovoltaic power generation, wind power generation and emergency systems. At the same time, it reduces mutual interference between multiple elevators, adapts to elevator groups of different sizes and types, and facilitates expansion and upgrading.

[0008] Preferably, the elevator energy-saving system in step S1 includes a bidirectional DC-DC device connected to the high-voltage DC bus of the cluster elevator; a unidirectional DC-DC device connected to the DC positive and negative poles of the photovoltaic panel to form a photovoltaic low-voltage DC power generation system; a unidirectional AC-DC device connected to the generator set of the wind turbine; and an energy storage device and an elevator emergency control system interconnected with the above devices through a low-voltage bus.

[0009] Preferably, the step S2 specifically includes that the bidirectional DC-DC device monitors in real time the voltage value U1 of the high-voltage DC bus of the cluster elevator and the voltage value U2 of the energy storage low-voltage bus.

[0010] Preferably, the voltage value U1 of the high-voltage DC bus of the elevator is in the range of: When the elevator is in a static state, the voltage range of its high-voltage DC bus voltage U1 is U 11 <U1<U 12 , within this range the elevator traction machine is at rest; When the elevator is in dynamic operation, the voltage value of the high-voltage DC bus voltage U1 will change. The maximum voltage value at this time is U max , the minimum voltage value is U min .

[0011] As a preferred embodiment, the step S3 sets the voltage lower limit protection value U of the energy storage low voltage bus 4. low And voltage upper limit protection value U up .

[0012] Preferably, the step S4 includes regulating the power transmission between the high-voltage DC bus and the energy storage low-voltage DC bus, specifically including: When Umin <U1<U 11 When the bidirectional DC-DC device switches to the discharge state, it transmits power to the high-voltage bus and determines whether U2 and U low The size of low When U2 low When , stop discharging; When U 12 <U1<U max When the bidirectional DC-DC device switches to the charging state, it transmits power to the low-voltage bus and determines whether U2 and U up The size of up When U2>U up Stop charging when When U 11 ≤U1≤U 12 When the bidirectional DC-DC device switches to the standby state; When U1 min Or U1>U max When the two-way DC-DC device determines that the elevator has a low voltage or high voltage fault, it switches to the standby state without affecting the normal operation of other interconnected elevators and similar two-way DC-DC devices.

[0013] Preferably, the step S4 includes regulating the power transmission between the photovoltaic panel and the energy storage low-voltage DC bus, specifically including: When U2 up When U2≥U up When , the unidirectional DC-DC device stops generating electricity; The unidirectional DC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P = min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional DC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

[0014] Preferably, the step S4 includes regulating the power transmission between the wind turbine and the energy storage low-voltage DC bus, specifically including: When U2 up ​​​​When U2≥U up When , the unidirectional AC-DC device stops generating electricity; The unidirectional AC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P = min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional AC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

[0015] Preferably, the step S5 of setting the SOC threshold of the energy storage device specifically includes real-time detection of the low-voltage bus voltage value U2 and the current value I in the energy storage unit, calculation of the real-time SOC value of the energy storage unit 21, and setting the upper limit SOC of the protection threshold. up and lower limit SOC low .

[0016] Preferably, the step S5 of regulating the SOC and power generation state of the energy storage device specifically includes: when SOC>SOC up When the charging limit power instruction P is sent to the bidirectional DC-DC device, the unidirectional DC-DC device and the unidirectional AC-DC device respectively. charge_limit ; When SOC <SOC low When the discharge limit power instruction P is sent to the bidirectional DC-DC device discharge_limit .

[0017] The beneficial effects of the present invention are: the high-power nickel-hydrogen battery energy storage system effectively takes into account both power and energy, can fully recover the potential energy of cluster elevators and utilize renewable energy, the system can adjust and control the state of charge (SOC) of high-power nickel-hydrogen batteries in real time, and realize intelligent power management of cluster elevators, photovoltaic power generation, wind power generation and emergency systems. In addition, the design and control method of the low-voltage busbar system minimizes the mutual interference between multiple elevators, adapts to elevator groups of different sizes and types, and is easy to expand and upgrade. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of the present invention.

[0019] Figure 2 It is a circuit principle connection structure block diagram of the present invention.

[0020] In the figure, 1 is a cluster elevator, 12 is a high-voltage DC bus, 2 is a high-power nickel-metal hydride battery energy storage device, 21 is an energy storage unit, 22 is an energy storage management system, 3 is a bidirectional DC-DC device, 4 is an energy storage low-voltage DC bus, 5 is a unidirectional DC-DC device, 6 is a photovoltaic panel, 7 is a unidirectional AC-DC device, 8 is a wind turbine, and 9 is an elevator emergency control system. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the technical solutions of the present application are further described in detail below through embodiments and in combination with the accompanying drawings. It should be understood that the specific implementation method described here is only an optimal embodiment of the present application, which is only used to explain the present application and does not limit the protection scope of the present application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] At present, lead-acid batteries and supercapacitors are the main solutions for elevator energy storage. However, the rate performance of lead-acid batteries is low, and they cannot efficiently recover the potential energy generated by the elevator during rapid descent, especially under high load conditions, and their energy release capacity is insufficient, which limits the energy recovery efficiency of the elevator. Although supercapacitors have fast charging and discharging characteristics, their relatively low energy density makes it difficult to provide sufficient energy support during long-term operation, especially in cluster elevator interconnection scenarios or scenarios connected to other renewable energy sources, and it is impossible to achieve a large amount of potential energy recovery and clean power utilization. Although the existing lead-acid battery / supercapacitor hybrid energy storage method takes into account the advantages of both of the above, the compatibility and complexity of the system make it difficult to further promote and apply. In order to solve the energy saving and control problems of cluster elevators or renewable energy elevators, the existing technology proposes cluster elevators and wind and solar energy-saving elevator control devices based on high-voltage DC microgrids. However, although such solutions recover elevator potential energy and utilize renewable energy to a certain extent, they have hidden dangers such as mutual influence between elevators and fault transmission. Therefore, in response to the above problems, the present invention proposes a new elevator energy-saving system and method to overcome the shortcomings of the prior art and achieve more efficient potential energy recovery and clean energy utilization.

[0023] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the drawings; the process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0024] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0025] Embodiment: An elevator energy saving method of this embodiment, such as Figure 1 As shown, the following steps are included: S1 builds an elevator energy-saving system on cluster elevators. The elevator energy-saving system includes a bidirectional DC-DC device connected to the high-voltage DC bus of the cluster elevator; a unidirectional DC-DC device connected to the positive and negative DC poles of the photovoltaic panel to form a photovoltaic low-voltage DC power generation system; a unidirectional AC-DC device connected to the generator set of the wind turbine; and an energy storage device and an elevator emergency control system interconnected with the above devices through a low-voltage bus.

[0026] S2 monitors the voltage values ​​of the high-voltage DC bus and the energy storage low-voltage bus, specifically, the bidirectional DC-DC device monitors the voltage value U1 of the high-voltage DC bus of the cluster elevator and the voltage value U2 of the energy storage low-voltage bus in real time.

[0027] The voltage value U1 range of the elevator's high-voltage DC bus is: When the elevator is in a static state, the voltage range of its high-voltage DC bus voltage U1 is U 11 <U1<U 12 , within this range the elevator traction machine is at rest; When the elevator is in dynamic operation, the voltage value of the high-voltage DC bus voltage U1 will change. The maximum voltage value at this time is U max , the minimum voltage value is U min .

[0028] S3 sets the voltage operating threshold of the high-voltage DC bus and the voltage protection threshold of the energy storage low-voltage bus, and sets the voltage lower limit protection value U of the energy storage low-voltage bus 4. low And voltage upper limit protection value U up .

[0029] S4 regulates power transmission according to the voltage value of the energy storage low-voltage bus and its voltage threshold.

[0030] Regulate the power transmission between the high-voltage DC bus and the energy storage low-voltage DC bus, including: When U min <U1<U 11 When the bidirectional DC-DC device switches to the discharge state, it transmits power to the high-voltage bus and determines whether U2 and U low The size of low When U2 low When , stop discharging; When U 12 <U1<U max ​When the bidirectional DC-DC device switches to the charging state, it transmits power to the low-voltage bus and determines whether U2 and U up The size of up When U2>U up Stop charging when When U 11 ≤U1≤U 12 When the bidirectional DC-DC device switches to the standby state; When U1 min Or U1>U max When the two-way DC-DC device determines that the elevator has a low voltage or high voltage fault, it switches to the standby state without affecting the normal operation of other interconnected elevators and similar two-way DC-DC devices.

[0031] The bidirectional DC-DC device 3 collects the charging and discharging power limit instructions sent by the energy storage management unit 22 in real time, and its charging and discharging power is implemented by the following formula: When receiving the power limit instruction sent by the energy storage management unit 22, P charge =min(P regen ,P charge_limit ), P discharge =min(P demand ,P discharge_limit ) When no power limit instruction is received from the energy storage management unit 22, P charge =P regen , P discharge =P demand Where P regen is the regenerative power of the traction machine, P demand is the required power of the traction machine, P charge_limit is the charging limit power sent by the energy storage management unit 22, P discharge_limit The discharge limit power sent by the energy storage management unit 22, P charge is the charging power of the DC-DC device 3, P discharge is the discharge power of the DC-DC device 3.

[0032] Regulate the power transmission between the photovoltaic panels and the energy storage low-voltage DC bus, including: When U2 up When U2≥U up When , the unidirectional DC-DC device stops generating electricity; ​​The unidirectional DC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P = min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional DC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

[0033] Regulate the power transmission between wind turbines and energy storage low-voltage DC bus, including: When U2 up When U2≥U up When , the unidirectional AC-DC device stops generating electricity; The unidirectional AC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P = min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional AC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

[0034] S5 sets the SOC threshold of the energy storage device and regulates the SOC and power generation status of the energy storage device. Setting the SOC threshold of the energy storage device specifically includes real-time detection of the low-voltage bus voltage value U2 and the current I in the energy storage unit, calculating the real-time SOC value of the energy storage unit 21, and setting the upper limit SOC of the protection threshold. up and lower limit SOC low .

[0035] When SOC>SOC up When the charging limit power instruction P is sent to the bidirectional DC-DC device, the unidirectional DC-DC device and the unidirectional AC-DC device respectively. charge_limit ; When SOC <SOC low When the discharge limit power instruction P is sent to the bidirectional DC-DC device discharge_limit .​

[0036] like Figure 2 As shown, the elevator energy-saving system consists of a cluster elevator 1, a nickel-hydrogen battery energy storage device 2, a bidirectional DC-DC device 3, a unidirectional DC-DC device 5, a photovoltaic panel 6, a unidirectional AC-DC device 7, a wind turbine 8, and an elevator emergency control system 9; wherein the cluster elevator 1 consists of multiple elevator systems, and the cluster elevator 1 consists of at least two or more elevator systems, supporting elevators of different brands or models. The elevator system includes a car, a traction machine, a rectifier module, an inverter module, a control circuit and a brake resistor connected thereto, etc.; the high-power nickel-hydrogen battery energy storage device 2 consists of an energy storage unit 21 and an energy storage management system 22; the energy storage management system 22 uses one or more of the voltage lookup table method or the time-based integration method to estimate the battery SOC state. wherein the energy storage unit 21 consists of a number of energy storage monomers connected in series or in parallel, and the DC nominal voltage of the nickel-hydrogen battery energy storage unit 21 connected in series and in parallel is 36 to 96V, and the voltage working range is 30 to 130V. The energy storage management system 22 includes a voltage and current acquisition and processing module; the DC-DC device 3 is connected to the high-voltage DC bus of the cluster elevator 1; the unidirectional DC-DC device 5 is connected to the DC positive and negative poles of the photovoltaic panel 6 to form a photovoltaic low-voltage DC power generation system; the unidirectional AC-DC device 7 is connected to the generator set of the wind turbine to form a wind power low-voltage DC power generation system; the high-power nickel-hydrogen battery energy storage device 2, the bidirectional DC-DC device 3, the unidirectional DC-DC device 5, the unidirectional AC-DC device 7, and the elevator emergency control system 9 are interconnected through a low-voltage bus; the energy storage management system 22 is respectively connected to the bidirectional DC-DC device 3, the unidirectional DC-DC device 5, and the unidirectional AC-DC device 7 through communication cables; the cluster elevator 1 and the elevator emergency control system 9 are interconnected through the AC bus of the mains.

[0037] The control method of the elevator energy-saving system includes the following key steps: S1, the bidirectional DC-DC device 3 monitors the voltage values ​​of the high-voltage DC bus 12 and the energy storage low-voltage bus 4 of the cluster elevator 1 in real time, and sets the voltage working threshold of the high-voltage DC bus 12 and the voltage protection threshold of the energy storage low-voltage bus 4 in the bidirectional DC-DC device 3, thereby regulating the power transmission between the high-voltage DC bus 12 and the energy storage low-voltage DC bus 4. The following steps are included: S1.1, DC-DC device 3 collects the elevator high-voltage DC bus voltage value U1 in real time. According to the working status of the elevator, the voltage range and related thresholds are defined as follows: When the elevator is in a static state, the voltage range of its high-voltage DC bus voltage U1 is U 11 <U1<U 12 , within this range the elevator traction machine is at rest; When the elevator is in dynamic operation, the voltage value of the high-voltage DC bus voltage U1 will change. The maximum voltage value at this time is U max , the minimum voltage value is U min； S1.2, DC-DC device 3 collects the voltage value U2 of energy storage low voltage DC bus 4 in real time, and sets the voltage lower limit protection value U2 of energy storage low voltage bus 4 in the device low , voltage upper limit protection value U up .

[0038] S1.3, through real-time monitoring of voltage U 1、 U 2， The DC-DC device 3 can determine the working state of the elevator and thus perform corresponding charging, discharging or standby operations: When U min <U1<U 11 When the DC-DC device 3 switches to the discharge state, it transmits power to the high-voltage bus. low The size of low When U2 low When , stop discharging.

[0039] When U 12 <U1<U max When the DC-DC device 3 switches to the charging state, it transmits power to the low-voltage bus. up The size of up When U2>U up Stop charging when

[0040] When U 11 ≤U1≤U 12 , the DC-DC device 3 switches to the standby state.

[0041] When U1 min Or U1>U max When the DC-DC device 3 determines that the elevator has a low voltage or high voltage fault, it switches to the standby state without affecting the normal operation of other interconnected elevators and similar DC-DC devices 3.

[0042] S1.4, the DC-DC device 3 collects the charging and discharging power limit instructions sent by the energy storage management unit 22 in real time, and its charging and discharging power executes the following formula: When receiving the power limit instruction sent by the energy storage management unit 22, P charge =min(P regen ,P charge_limit ), P discharge =min(P​​demand ,P discharge_limit ) When no power limit instruction is received from the energy storage management unit 22, P charge =P regen , P discharge =P demand Where P regen is the regenerative power of the traction machine, P demand is the required power of the traction machine, P charge_limit is the charging limit power sent by the energy storage management unit 22, P discharge_limit The discharge limit power sent by the energy storage management unit 22, P charge is the charging power of the DC-DC device 3, P discharge is the discharge power of the DC-DC device 3.

[0043] S2, the unidirectional DC-DC device 5 monitors the voltage value of the energy storage low-voltage bus 4 in real time, and sets the upper voltage protection threshold of the voltage value of the energy storage low-voltage bus 4 in the unidirectional DC-DC device 5, and regulates the transmission of electric energy of the photovoltaic panel 6 to the energy storage low-voltage DC bus 4 by the voltage value of the energy storage low-voltage bus 4 and the size of its voltage threshold. The steps include: S2.1, the unidirectional DC-DC device 5 stores the voltage value U2 of the low-voltage DC bus 4 in real time, and sets the voltage upper limit protection value U2 of the low-voltage bus 4 in the DC-DC device 5 up .

[0044] By real-time monitoring of voltage U 2， Switching unidirectional DC-DC device 5 to power generation state: When U2 up When U2≥U up When , the DC-DC device 5 stops generating electricity.

[0045] S2.2, the unidirectional DC-DC device 5 collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power executes the following formula: When receiving the charging limit power instruction, P = min (P pv ,P charge_limit ); When receiving the charging limit power instruction, P = P pv ; Where P is the power generated by the unidirectional DC-DC device 5, P pv is the maximum power that can be generated by the photovoltaic panel, P charge_limit It is the charging limit power sent by the energy storage management unit 22. ​

[0046] S3, the unidirectional AC-DC device 7 monitors the voltage value of the energy storage low-voltage bus 4 in real time, and sets the upper voltage protection threshold of the voltage value of the energy storage low-voltage bus 4 in the unidirectional AC-DC device 5, and controls the transmission of electric energy of the wind turbine 8 to the energy storage low-voltage DC bus 4 by the voltage value of the energy storage low-voltage bus 4 and the size of its voltage threshold. The following steps are included: S3.1, the unidirectional AC-DC device 7 stores the voltage value U2 of the low-voltage DC bus 4 in real time, and sets the voltage upper limit protection value U2 of the low-voltage bus 4 in the unidirectional AC-DC device 7 up .

[0047] By real-time monitoring of the voltage U2, the unidirectional AC-DC device 7 is switched to a power generation state: when U2 up When U2≥U up When , the unidirectional AC-DC device 7 stops generating electricity.

[0048] S3.2, the unidirectional AC-DC device 7 collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is implemented by the following formula: When receiving the charging limit power instruction, P = min (P pv ,P charge_limit ); When receiving the charging limit power instruction, P = P pv ; Where P is the power generated by the unidirectional AC-DC device 7, P pv is the maximum power that can be generated by wind turbine 8, P charge_limit It is the charging limit power sent by the energy storage management unit 22.

[0049] S4, the elevator emergency control system 9 detects the voltage value of the AC bus 10 of the mains in real time, and according to the mains power outage, activates the high-power nickel-hydrogen energy storage device 2 or the electric energy generated by wind power / photovoltaic operation, and provides control power to the elevator through the elevator emergency device to ensure the safe stop of the elevator and the normal operation of the emergency lighting.

[0050] S5, the energy management system 22 in the high-power nickel-hydrogen energy storage device 2 detects the low-voltage bus voltage value in real time, collects the current flowing through the energy storage unit 21, and estimates the SOC state of the nickel-hydrogen battery energy storage device in real time. The energy storage management system sets the SOC upper and lower limit thresholds, and through the judgment of the SOC value and its upper and lower limit thresholds, sends power limit instructions to the DC-DC device 3, DC-DC device 4, and AC-DC device 5, and intelligently allocates the energy storage unit SOC and the wind power / photovoltaic power generation status. It includes the following steps: ​S5.1. The energy management system 22 in the high-power nickel-hydrogen battery energy storage device 2 detects the low-voltage bus voltage value U2 and the current size I in the energy storage unit 21 in real time, and calculates the real-time SOC value of the energy storage unit 21 by the time integration method of the current size or the voltage value table lookup method under different currents.

[0051] S5.2. Setting SOC in energy management system 22 up , SOC low Protection threshold. When SOC>SOC up When the charging power instruction P is sent to the DC-DC device 3, the DC-DC device 4, and the AC-DC device 5 respectively charge_limit ; When SOC <SOC low When the discharge power instruction P is sent to the DC-DC device 3 discharge_limit .

[0052] Embodiment 1 Embodiment 1 of the present application provides a Figure 2An elevator energy-saving system is shown, which consists of a cluster elevator 1, a high-power nickel-hydrogen energy storage device 2, a bidirectional DC-DC device 3, a unidirectional DC-DC device 5, a photovoltaic panel 6, a unidirectional AC-DC device 7, a wind turbine 8, and an elevator emergency control system 9; wherein the cluster elevator 1 is composed of three elevator systems, specifically Hitachi Elevator GST-HL160G (inverter bus voltage range 240V to 370V, rated power 15kW), Giant KONE Elevator GPS53E (inverter bus voltage range 550V to 680V, ​​rated power 13.3kW) and Mitsubishi Elevator MAXIEZ-CZ (inverter bus voltage range 530V to 700V, rated power 11kW); the Each elevator system includes a car, a traction machine, a rectifier module, an inverter module, a control circuit and a brake resistor connected to it; the high-power nickel-hydrogen battery energy storage device 2 is composed of an energy storage unit 21 and an energy storage management system 22; wherein, the energy storage unit 21 adopts a cylindrical 90940 nickel-hydrogen battery cell, a 40 series and 1 parallel configuration, providing a nominal DC voltage of 48V, a voltage operating range of 40V to 64V, a continuous charge and discharge current of up to 500A, and supports a high-power input and output of 24kW; the model of the energy storage management system 22 is the Hangzhou Xingyun XYBMS master-slave control integrated system, which includes 24 voltage and 6 temperature sampling channels, and real-time monitoring and management of the voltage, current and other parameters of the energy storage unit. Among them, the three bidirectional DC-DC devices 3 connected to Hitachi Elevator, Giant KONE Elevator and Mitsubishi Elevator have high voltage ranges of 200-400V, 500-800V, and 500-800V, respectively, and low voltage ranges of 40V-64V, with rated powers of 10kW, and support the setting of upper and lower working voltage limits, which can realize the recovery and efficient management of elevator regenerative energy; the unidirectional DC-DC device 5 is connected to the DC positive and negative poles of the photovoltaic panel 6 to form a photovoltaic low-voltage DC power generation system with a rated power of 1kW, which is mainly responsible for transmitting the DC power generated by photovoltaic power generation to the energy storage unit; the unidirectional AC-DC device 7 is connected to the wind turbine 8 to form a wind power low-voltage DC power generation system with a rated power of 1kW. The rated power is 2kW, which is responsible for converting the AC power generated by the wind turbine into DC power for use in the system; the high-power nickel-hydrogen battery energy storage device 2, the bidirectional DC-DC device 3, the unidirectional DC-DC device 5, the unidirectional AC-DC device 7, and the elevator emergency control system 9 are all interconnected through a low-voltage bus; the energy storage management system 22 is respectively connected to the bidirectional DC-DC device 3, the unidirectional DC-DC device 5, and the unidirectional AC-DC device 7 through communication cables, and communicates using the RS485 protocol; the cluster elevator 1 and the elevator emergency control system 9 are interconnected through the AC bus of the mains power supply. When the mains power is interrupted, the energy storage unit 2 can provide emergency power to ensure the normal operation of the elevator.

[0053] Embodiment 2 Based on the first embodiment, the second embodiment of the present application provides an elevator energy saving method: S1, the bidirectional DC-DC device 3 monitors the voltage value of the high-voltage DC bus 12 of the cluster elevator 1 and the voltage value of the energy storage low-voltage bus 4 in real time, and sets the voltage threshold of the high-voltage DC bus 12 and the voltage protection threshold of the energy storage low-voltage bus 4 in the bidirectional DC-DC device 3, and controls the power transmission between the high-voltage DC bus 12 and the energy storage low-voltage DC bus 4 by the voltage value of the high-voltage DC bus 12 and the size of its voltage threshold, and limits the power transmission between the high-voltage DC bus 12 and the energy storage low-voltage DC bus 4 by the voltage value of the energy storage low-voltage bus 4 and the size of its voltage threshold.

[0054] S2. The unidirectional DC-DC device 5 monitors the voltage value of the energy storage low-voltage bus 4 in real time, and sets an upper voltage protection threshold of the voltage value of the energy storage low-voltage bus 4 in the unidirectional DC-DC device 5, and limits the transmission of electric energy from the photovoltaic panel 6 to the energy storage low-voltage DC bus 4 through the voltage value of the energy storage low-voltage bus 4 and the size of its voltage threshold.

[0055] S3, the unidirectional AC-DC device 7 monitors the voltage value of the energy storage low-voltage bus 4 in real time, and sets the upper voltage protection threshold of the voltage value of the energy storage low-voltage bus 4 in the unidirectional AC-DC device 5, and limits the transmission of electric energy of the wind turbine 8 to the energy storage low-voltage DC bus 4 through the voltage value of the energy storage low-voltage bus 4 and the size of its voltage threshold.

[0056] S4, the elevator emergency control system 9 detects the voltage value of the AC bus 10 of the mains in real time, and according to the mains power outage, activates the nickel-hydrogen battery energy storage device or the electricity generated by wind power and photovoltaic power during operation, and provides control power for the elevator through the elevator emergency device to ensure the safe stop of the elevator and the normal operation of the emergency lighting.

[0057] S5, the energy management system 22 in the nickel-hydrogen battery energy storage device 2 detects the low-voltage bus voltage value in real time, collects the current flowing through the energy storage unit 21, and estimates the SOC state of the nickel-hydrogen battery energy storage device in real time. The energy storage management system sets the SOC upper and lower limit thresholds, and through the judgment of the SOC value and its upper and lower limit thresholds, issues power limit instructions to the DC-DC device 3, DC-DC device 4, and AC-DC device 5, and intelligently allocates the energy storage unit SOC and the power generation state of wind power and photovoltaic.

[0058] S1.1, DC-DC device 3 collects the elevator high-voltage DC bus voltage value U1 in real time. When the elevator is in a static state, the voltage range of its high-voltage DC bus voltage U1 is 550V=U 11 <U1<U 12= 560V, within this range the elevator traction machine is in a stationary state; when the elevator is running dynamically, the highest voltage value of the high-voltage DC bus voltage U1 is U max = 680V, the lowest voltage value is U min = 530V.

[0059] S1.2. The DC-DC device 3 collects the voltage value U2 of the energy storage low-voltage DC bus 4 in real time, and sets the lower voltage limit protection value U low = 40V and the upper voltage limit protection value U up = 60V.

[0060] S1.3. By monitoring the voltage U 1、 U 2， in real time, the DC-DC device 3 can judge the working state of the elevator, and then perform corresponding charging, discharging or standby operations: When 530V < U1 < 550V, the DC-DC device 3 switches to the discharging state and transmits power to the high-voltage bus. If U2 ≥ 40V at this time, the discharging state is maintained; if U2 < 40V, the discharging stops.

[0061] When 560V < U1 < 680V, the DC-DC device 3 switches to the charging state and transmits power to the low-voltage bus. If U2 ≤ 60V at this time, the charging state is maintained; if U2 > 60V p at this time, the charging stops.

[0062] When 550V ≤ U1 ≤ 560V, the DC-DC device 3 switches to the standby state.

[0063] When U1 < 530V or U1 > 680V, the DC-DC device 3 judges that the elevator has a low-voltage or high-voltage fault and switches to the standby state.

[0064] S1.4. The DC-DC device 3 executes the following formula for its charging and discharging power according to the instruction for limiting the charging and discharging power sent by the energy storage management unit 22 collected in real time: When receiving the power limit instruction sent by the energy storage management unit 22, P charge = min(P regen , P charge_limit ), P discharge = min(P demand , P discharge_limit ) When not receiving the power limit instruction sent by the energy storage management unit 22, P charge = P regen , P discharge = P demand Where P regen is the regenerative power of the traction machine, P demand is the required power of the traction machine, P charge_limit is the charging limit power sent by the energy storage management unit 22, P discharge_limit The discharge limit power sent by the energy storage management unit 22, P charge is the charging power of the DC-DC device 3, P discharge is the discharge power of the DC-DC device 3.

[0065] S2.1, the unidirectional DC-DC device 5 stores the voltage value U2 of the low-voltage DC bus 4 in real time, and sets the voltage upper limit protection value U2 of the low-voltage bus 4 in the DC-DC device 5 up is 60V.

[0066] By real-time monitoring of voltage U 2， Switch the unidirectional DC-DC device 5 to the power generation working state: when U2<60V, the unidirectional DC-DC device 5 automatically switches to the power generation state and transmits power to the low-voltage bus; when U2≥60V, the DC-DC device 5 stops generating power.

[0067] S2.2, the unidirectional DC-DC device 5 collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power executes the following formula: When receiving the charging limit power instruction, P = min (P pv ,P charge_limit ); When receiving the charging limit power instruction, P = P pv ; Where P is the power generated by the unidirectional DC-DC device 5, P pv is the maximum power that can be generated by the photovoltaic panel, P charge_limit It is the charging limit power sent by the energy storage management unit 22.

[0068] The specific steps of step S3 are similar to those of step S2 and will not be described in detail.

[0069] S5.1. The energy management system 22 in the nickel-hydrogen battery energy storage device 2 detects the low-voltage bus voltage value U2 and the current magnitude I in the energy storage unit 21 in real time, and calculates the real-time SOC value of the energy storage unit 21 by time integration of the current magnitude.

[0070] S5.2. Setting SOC in energy management system 22 up The threshold is 80%, SOC low The threshold is 20%. When SOC>80%, a charging power instruction P is sent to DC-DC device 3, DC-DC device 4, and AC-DC device 5 respectively. charge_limit; When SOC <SOC low When the discharge power instruction P is sent to the DC-DC device 3 discharge_limit .

[0071] The energy management system 22 sets the SOCup and SOCdown protection thresholds, where SOCup = 80% and SOCdown = 20%. When SOC>80%, a charging power instruction P is issued to the DC-DC device 3, the DC-DC device 4, and the AC-DC device 5 respectively. charge_limit When SOC<20%, a discharge power instruction P is issued to the DC-DC device 3. discharge_limit is 0kW.

[0072] Through the embodiments of the present invention, the overall energy efficiency of the elevator system is significantly improved. Compared with the prior art, the energy saving effect of the system is improved by about 30%, and the proportion of mains power consumption is reduced by more than 70%. In addition, the intelligent energy management system significantly reduces the risk of system operation and improves the reliability and safety of the entire cluster elevator system.

[0073] The specific embodiments described herein are merely examples of the spirit of the present invention. The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that a technician in the technical field to which the present application belongs may make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but will not deviate from the spirit of the present application or exceed the scope defined in the attached claims. For a person of ordinary skill in the art, multiple variations and improvements may also be made without departing from the concept of the present application. Therefore, the scope of protection of this patent shall be subject to the attached claims.

Claims

1. An elevator energy saving method, characterized in that: The following steps are involved: S1 builds an elevator energy-saving system on cluster elevators; S2 monitors the voltage values ​​of the high-voltage DC bus and the energy storage low-voltage bus; S3 sets the voltage operating threshold of the high-voltage DC bus and the voltage protection threshold of the energy storage low-voltage bus; S4 regulates the power transmission according to the voltage value of the energy storage low-voltage bus and its voltage threshold; S5 sets the SOC threshold of the energy storage device and regulates the SOC and power generation status of the energy storage device.

2. An elevator energy saving method according to claim 1, characterized in that: The elevator energy-saving system in step S1 includes a bidirectional DC-DC device connected to the high-voltage DC bus of the cluster elevator; A unidirectional DC-DC device is connected to the positive and negative DC poles of the photovoltaic panel to form a photovoltaic low-voltage DC power generation system; a unidirectional AC-DC device is connected to the generator set of the wind turbine; and an energy storage device and an elevator emergency control system are interconnected with the above devices through a low-voltage bus.

3. An elevator energy saving method according to claim 2, characterized in that: The step S2 specifically includes that the bidirectional DC-DC device monitors the voltage value U1 of the high-voltage DC bus of the cluster elevator and the voltage value U2 of the energy storage low-voltage bus in real time.

4. An elevator energy saving method according to claim 3, characterized in that: The voltage value U1 range of the high-voltage DC bus of the elevator is: When the elevator is in a static state, the voltage range of its high-voltage DC bus voltage U1 is U 11 <U1<U 12 , within this range the elevator traction machine is at rest; When the elevator is in dynamic operation, the voltage value of the high-voltage DC bus voltage U1 will change. The maximum voltage value at this time is U max , the minimum voltage value is U min .

5. The elevator energy saving method according to claim 3, characterized in that: The step S3 sets the voltage lower limit protection value U of the energy storage low voltage bus 4 low And voltage upper limit protection value U up .

6. An elevator energy saving method according to claim 5, characterized in that: The step S4 includes regulating the power transmission between the high-voltage DC bus and the energy storage low-voltage DC bus, specifically including: WhenU min <U1<U 11 When the bidirectional DC-DC device switches to the discharge state, it transmits power to the high-voltage bus and determines whether U2 and U low The size of low When U2 low When , stop discharging;​ WhenU 12 <U1<U max When the bidirectional DC-DC device switches to the charging state, it transmits power to the low-voltage bus and determines whether U2 and U up The size of up When U2>U up Stop charging when WhenU 11 ≤U1≤U 12 When the bidirectional DC-DC device switches to the standby state; When U1 min Or U1>U max When the two-way DC-DC device determines that the elevator has a low voltage or high voltage fault, it switches to the standby state without affecting the normal operation of other interconnected elevators and similar two-way DC-DC devices.​ 7. An elevator energy saving method according to claim 5 or 6, characterized in that: The step S4 includes regulating the power transmission between the photovoltaic panel and the energy storage low-voltage DC bus, specifically including: When U2 up When U2≥U up When , the unidirectional DC-DC device stops generating electricity;​ The unidirectional DC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P=min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional DC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

8. An elevator energy saving method according to claim 5 or 6, characterized in that: The step S4 includes regulating the power transmission between the wind turbine and the energy storage low-voltage DC bus, specifically including: When U2 up When U2≥U up When , the unidirectional AC-DC device stops generating electricity;​ The unidirectional AC-DC device collects the charging power limit instruction sent by the energy storage management unit 22 in real time, and its power generation power is calculated according to the following formula: When receiving a charging limit power command P=min(P pv ,P charge_limit ) When receiving a charging limit power command P=P pv Where P is the power generated by the unidirectional AC-DC device, P pv is the maximum power generation of the photovoltaic panel, P charge_limit Limit power for charging.

9. An elevator energy saving method according to claim 2, characterized in that: The step S5 of setting the SOC threshold of the energy storage device specifically includes real-time detection of the low-voltage bus voltage value U2 and the current I in the energy storage unit, calculating the real-time SOC value of the energy storage unit 21, and setting the upper limit SOC of the protection threshold. up and lower limit SOC low .

10. An elevator energy saving method according to claim 9, characterized in that: The step S5 of regulating the SOC and power generation state of the energy storage device specifically includes: when SOC>SOC up When the charging limit power instruction P is sent to the bidirectional DC-DC device, the unidirectional DC-DC device and the unidirectional AC-DC device respectively. charge_limit ; When SOC <SOC low When the discharge limit power instruction P is sent to the bidirectional DC-DC device discharge_limit .

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