CN103241619B - The control method of a kind of energy-conserving elevator and operation thereof - Google Patents

Abstract

The control method of a kind of energy-conserving elevator and operation thereof on electrical motor, is coaxially arranged with power-transfer clutch be communicated with fluid control valve with hydraulic pump/motor, is provided with pressure sensor, energy storage is communicated with computing machine, realize the Energy Saving Control to overall elevator.The present invention adopts hydraulic accumulator energy storage, and the technology maturation life-span is long, improves the braking deceleration performance of electrical motor simultaneously, shortens the motor braking time, operate steadily, safe and reliable.

Description

An energy-saving elevator and its operation control method

technical field

The present invention relates to an elevator and its control method, and furthermore, it is a method for controlling the energy-saving operation of the elevator by utilizing the electro-hydraulic energy storage structure to regenerate the potential energy of the elevator's downward load and the kinetic energy consumed in the deceleration and braking process.

Background technique

With the acceleration of my country's urbanization process and the rapid development of high-rise buildings, the use and annual output of elevators are also increasing rapidly. In the long run, the number of elevators in my country will be very large, because elevators often have to carry heavy loads during use. Downward, continuous acceleration and deceleration, therefore, there is a lot of potential energy and kinetic energy that can be further saved and utilized. Therefore, under the background that the country vigorously advocates energy conservation and emission reduction, the development of new technologies for elevator energy conservation and the regeneration and utilization of this part of energy will have important economic and social value.

There are many methods currently available to reduce energy consumption during elevator operation. One of the low-cost methods is to convert the energy generated by the elevator’s downward movement and braking into electrical energy and store it in the battery. Although battery energy storage has a low price advantages, but the charging and discharging of the battery cannot withstand large currents, and it is impossible to fully absorb the regenerative energy of the elevator; the number of charging and discharging does not match the operating frequency of the elevator, and the life is short. In order to protect the battery, it is necessary to use resistance auxiliary braking.

A frequency converter with energy feedback is used to control the running speed of the elevator. Even if the motor has four-quadrant working characteristics, the potential energy and kinetic energy of the elevator's load-bearing downward movement and deceleration braking can be used. However, because there is no energy storage element in the power grid, a large number of elevators are running Randomly feeding power to the grid will cause a large current impact and harmonic interference to the grid, affecting the quality of the grid. Therefore, the promotion and application are subject to certain restrictions.

A patent authorized by the United States Patent Office in 2010, patent number: US 7,681,694 B2, discloses an elevator energy-saving operation scheme that uses a flywheel battery as an energy storage unit, that is, on the DC bus of the frequency converter that controls the elevator speed, A unit dedicated to controlling the speed of the flywheel is also connected, but the technology of flywheel energy storage is still immature, especially when it needs to operate in a vacuum environment, and the current technical level is difficult to meet.

A patent authorized by the United States Patent Office in 2004, patent number: US 6,742,630 B2, discloses an elevator energy-saving operation scheme using super capacitors as energy storage units, through DC-DC converters, the energy generated during elevator operation Stored in supercapacitors, compared with traditional batteries or ordinary capacitors, although supercapacitors have the advantages of fast charging and discharging points and long life, but this technology is still in the development stage, and the withstand voltage of a single energy storage unit is very low. Only a series-parallel combination of supercapacitors can be used. Many technologies have yet to be broken through, and they are not yet practical.

The two power-saving methods mentioned above are the conversion of energy storage and energy release through the DC bus, and cannot directly apply torque to the motor, so the installed power of the motor cannot be reduced, and it is not helpful for the safe operation of the motor.

Contents of the invention

The purpose of the present invention is to solve the technical difficulties of the existing elevator system using energy-consuming braking, low energy efficiency, feeding power to the grid, having a large impact on the grid, immature flywheel and supercapacitor energy storage technology, and difficult for users to benefit directly, and Provided is an energy-saving elevator capable of reducing installed power, recovering and reusing potential energy and kinetic energy in the process of elevator lowering and deceleration and braking, and a control method for its operation.

In order to solve the above-mentioned technical difficulties, the technical solution adopted by the present invention is an energy-saving elevator and its operation control method, wherein, the provided energy-saving elevator includes a motor; its characteristic is that a clutch and a Hydraulic pump/motor, the two oil ports of the hydraulic pump/motor are respectively connected with the first oil outlet A and the second oil outlet B of the hydraulic control valve, when the hydraulic control valve is in the neutral position, the first oil outlet A. The second oil outlet B is connected to the oil return port T, the oil inlet P of the hydraulic control valve, the oil port of the hydraulic accumulator and the oil inlet of the safety valve are connected; and a pressure sensor is installed to detect the accumulator The internal oil pressure of the elevator is equipped with a computer connected with a pressure sensor, a hydraulic control valve and a clutch to realize energy-saving control of the overall elevator.

In the technical scheme of the above-mentioned energy-saving elevator, the further technical scheme is as follows:

The adopted hydraulic pump/motor is a quantitative hydraulic pump/motor, or an electronically controlled variable displacement proportional hydraulic pump/motor.

The adopted hydraulic control valve is an electromagnetic reversing valve or an electromagnetic proportional valve.

The hydraulic accumulator used is one accumulator, or an accumulator group composed of two or more accumulators.

The hydraulic oil tank adopted is a low-pressure hydraulic accumulator.

Provided is a control method for the operation of the above-mentioned energy-saving elevator, the energy-saving control method is that when the elevator goes down under a load greater than the balance weight, or goes up under a load less than the balance weight, the motor is in the power generation state, and the frequency converter The voltage rises and is controlled by the control computer to input the output signal of the DC voltage sensor to the DC voltage sensor. The output signal of the DC voltage sensor also increases accordingly, and the control computer sends a control signal to the hydraulic control valve to make the hydraulic control valve switch to the working position; when the elevator goes up, The P port of the hydraulic control valve is connected to the B port. When the elevator is going down, the P port is connected to the A port. When the load is heavy, or when the load is greater than the balance weight, the motor is in the electric state, and the voltage in the frequency converter will not rise. To the working position, the hydraulic pump/motor is in the working state of the hydraulic motor, the auxiliary drive motor runs, and the oil in the hydraulic accumulator is discharged into the hydraulic oil tank.

Compared with the existing energy-saving elevator, the energy-saving elevator and its operation control method described above in the present invention have the advantages and positive effects that it directly brings and inevitably produces: it can effectively reduce the energy-saving effect of the elevator. It is reflected in the user's electricity bill; it will not have an impact on the power grid, and can assist in maintaining the stability of the elevator operation under abnormal fluctuations in the power supply voltage of the power grid; in the case of peak power consumption or use of backup power, it can compensate for the acceleration of the elevator The peak power of the elevator reduces the pressure on the power grid, especially in the case of a power failure, the system using the energy storage device can maintain the operation of the elevator for a period of time, expanding the function of the elevator emergency leveling device; the braking resistor can be saved , directly recycle the kinetic energy of motor deceleration and braking and the potential energy provided by the external load, so that the asynchronous motor has the ability to work in four quadrants; it reduces the heat generation of the motor and further improves the service life of the motor; it does not need to go through a complicated inverter unit Feed power to the grid, that is, it can store and utilize the electric energy generated by the motor in the power generation condition, and at the same time improve the braking deceleration performance of the motor and shorten the braking time of the motor; compared with the use of super capacitors and flywheel batteries, hydraulic accumulators are used Capable, mature technology, reliable operation, long life.

Description of drawings

Fig. 1 is the schematic structural diagram of the principle structure of the energy-saving elevator and its operation control method using quantitative hydraulic pump/motor in the present invention;

In the figure: 1: car; 2: counterweight; 3: electric motor; 4: inverter; 5; battery; 6: clutch; 7: hydraulic pump/motor; 8: hydraulic accumulator; 9: hydraulic control valve; 10: Safety valve; 11: DC voltage sensor; 12: Control computer; 13: Pressure sensor; 14: Hydraulic oil tank.

A: Oil outlet I; B: Oil outlet II; T: Oil return port, P: Oil inlet.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Specific implementation mode 1

As shown in accompanying drawing 1, implement a kind of energy-saving elevator provided by the present invention, comprise car 1, counterweight 2, electric motor 3, frequency converter 4, accumulator 5, control computer 12, feature is to set up clutch 6, Hydraulic pump/motor 7, hydraulic accumulator 8, hydraulic control valve 9, safety valve 10, DC voltage sensor 11, pressure sensor 13 and hydraulic oil tank 14. The electric motor 3, the clutch 6 and the hydraulic pump/motor 7 are coaxially connected, and the two oil ports of the hydraulic pump/motor 7 are respectively connected with the first oil outlet A and the second oil outlet B of the hydraulic control valve 9, and the hydraulic control valve When 9 is in the neutral position, the first oil outlet A, the second oil outlet B and the oil return port T are connected, the oil inlet P of the hydraulic control valve 9, the oil port of the hydraulic accumulator 8 and the inlet of the safety valve 10 The oil port communicates with the pipeline, and the pressure sensor 13 is connected to the pipeline communicating with the hydraulic accumulator 8 to detect the oil pressure inside the accumulator 8. The output signal of the pressure sensor 13 is connected to the control computer 12, and the DC voltage sensor 11 Connected to the DC bus of the frequency converter 4 to detect the voltage of the DC bus, the output signal of the DC voltage sensor 11 is connected to the control computer 12, and the output signal of the control computer 12 is connected to the electromagnet of the hydraulic control valve 9, and the control computer 12 simultaneously Control the disengagement and reunion of clutch 6.

Wherein, the implementation of the hydraulic pump/motor 7 may be a quantitative hydraulic pump/motor, or an electronically controlled variable displacement proportional hydraulic pump/motor. The hydraulic control valve 9 described above may be an electromagnetic reversing valve or an electromagnetic proportional valve. The implementation of the hydraulic accumulator 8 may be one accumulator, or an accumulator group composed of two or more accumulators. Implementing the described hydraulic oil tank 14 is to select a low-pressure hydraulic accumulator for use.

Specific implementation mode 2

As shown in accompanying drawing 1, implement the operation control method of a kind of energy-saving elevator provided by the present invention, the working process of this system is, when the elevator goes down under the load that is greater than the balance weight, or goes up under the load that is less than the balance weight, the motor 3 In the state of power generation, the voltage in the DC bus 4 is increased. The increased voltage value is detected by the DC voltage sensor 11 and then input to the control computer 12. According to the detected DC voltage value, the control computer 12 sends a control signal to the hydraulic pressure. The control valve 9 makes the hydraulic control valve 9 switch to the working position. When the elevator goes up, the P port of the hydraulic control valve 9 is connected to the B port. When the elevator goes down, the P port is connected to the A port. The motor 3 drives the hydraulic pump/motor 7 In the working condition of the hydraulic pump, the oil is pumped from the hydraulic oil tank 14 into the hydraulic accumulator 8 to store the gravitational potential energy during the operation of the elevator; Uplink, the motor 3 is in the electric state, and the voltage in the DC bus will not rise. When the elevator is in the process of accelerating, the control computer 12 controls the hydraulic control valve 9 to be in the neutral position or reversed according to the signal given by the pressure sensor 13. Working position, if the pressure in the hydraulic accumulator 8 reaches the set threshold, the hydraulic control valve is switched to the working position, the pressure oil in the accumulator drives the hydraulic pump/motor 7 to be in the hydraulic motor working condition, and the hydraulic accumulator The oil in the accumulator 8 is discharged into the hydraulic oil tank 14, the auxiliary drive motor 3 runs, and the stored energy is regenerated; when the pressure in the hydraulic accumulator 8 does not reach the set threshold, the control computer 12 does not provide hydraulic pressure. The control valve 9 reversing signal, the hydraulic control valve 9 maintains a short-circuit state in the neutral position; when there is a component in the hydraulic energy storage system, such as the hydraulic accumulator 8, the hydraulic control valve 9, or the hydraulic pump/motor 7 fails, The control computer 12 gives a signal to the clutch 6 to disengage the hydraulic energy storage unit from the elevator system without affecting the normal operation of the elevator.

Claims (6)

1. An energy-saving elevator, comprising a motor [3]; It is characterized in that a clutch [6] and a hydraulic pump/motor [7] are coaxially arranged on the motor [3], and the two hydraulic pumps/motors [7] The two oil ports are respectively connected with the first oil outlet A and the second oil outlet B of the hydraulic control valve [9]. When the hydraulic control valve [9] is in the neutral position, the first oil outlet A and the second oil outlet B communicates with the oil return port T, the oil inlet P of the hydraulic control valve [9], the oil port of the hydraulic accumulator [8] and the oil inlet of the safety valve [10] are connected; and a pressure sensor [13] is provided ] to detect the internal oil pressure of the hydraulic accumulator [8], a control computer [12] is provided to connect the pressure sensor [13], the hydraulic control valve [9] and the clutch [6] to realize the energy-saving control of the whole elevator. 2. The energy-saving elevator according to claim 1, characterized in that the hydraulic pump/motor [7] is a quantitative hydraulic pump/motor or an electronically controlled variable displacement proportional hydraulic pump/motor. 3. The energy-saving elevator according to claim 1, characterized in that the hydraulic control valve [9] is an electromagnetic reversing valve or an electromagnetic proportional valve. 4. The energy-saving elevator according to claim 1, characterized in that the hydraulic accumulator [8] is an accumulator or an accumulator group composed of two or more accumulators. 5. The energy-saving elevator according to claim 1, characterized in that the hydraulic oil tank [14] is a low pressure hydraulic accumulator. 6. A control method for the operation of an energy-saving elevator according to claim 1, wherein the control method is that when the elevator goes down under a load greater than the balance weight, or goes up under a load less than the balance weight, the motor [3] is at In the power generation state, the voltage in the frequency converter [4] rises and is input to the DC voltage sensor [11] by the control computer [12], and the output signal of the DC voltage sensor [11] also increases correspondingly, and the control computer [12] gives The control signal is sent to the hydraulic control valve [9] to switch the direction of the hydraulic control valve [9] to the working position. When the elevator goes up, the P port of the hydraulic control valve is connected to the B port. When the elevator goes down, the P port is connected to the A port. The pump/motor [7] is in the working condition of the hydraulic pump, pumping oil from the hydraulic oil tank [14] into the hydraulic accumulator [8]; Up, the motor [3] is in the electric state, the voltage in the frequency converter [4] will not rise, the control computer [12] controls the hydraulic control valve [9] to be in the neutral position or It is reversing to the working position, the hydraulic pump/motor [7] is in the hydraulic motor working condition, the auxiliary drive motor [3] runs, and the oil in the hydraulic accumulator [8] is discharged into the hydraulic oil tank [14].