RU2765200C1 - Method and system for elevator evacuation and controller - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: method and system for elevator evacuation and a controller are proposed. An engine is switched to a short-circuit state, an elevator cabin is switched to a sliding state, when it is detected that the primary power source is unavailable. After a predetermined time, short-circuit states of the engine are removed, and open-loop control is carried out on the engine in such a way that an inverter module applies voltage to the engine. In this case, the engine uses energy generated by sliding to charge an energy-storing component on a high-power DC bus after detecting the voltage applied by the inverter module. Closed-loop control is carried out on the engine, when it is detected that the engine enters a predetermined stable state, so that the engine rotation speed reaches a predetermined evacuation speed. The engine rotation speed is reduced to zero, and the engine is stopped based on closed-loop control. Next, sliding of the cabin is stopped in such a way that the elevator cabin stops in an aligned position, and an elevator cabin door is opened, when it is detected that the elevator cabin is moved to a predetermined distance from the aligned position.

EFFECT: described method makes it possible to control the elevator with a smooth start, reverse alignment and cabin stopping, when the primary power source is unavailable, and the DC bus voltage drops to very low value or even to zero.

17 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The present application generally relates to the field of elevator control, and more specifically, to an elevator evacuation method and system, and a controller.

BACKGROUND OF THE INVENTION

With the development of elevator control technology, the safety and fault tolerance requirements of elevator system customers are increasing. In general, when an elevator system is installed in a building, it is necessary that the elevator system has an emergency evacuation function that can quickly initiate the opening of the door after moving to the leveled position in the event of a power failure, to safely evacuate passengers. There are several schemes for the implementation of emergency evacuation of the elevator in the event of a power failure.

1. An uninterruptible power supply/uninterruptible power supply (UPS) or automatic evacuation device (ARD) can be provided for emergency evacuation of the elevator. When the mains fails, some of the capacity of the energy stored in the battery is converted into electrical energy to supply electrical power to the frequency converter in the form of single-phase alternating current (AC) (basically simulating 220V mains power, and some of them have square waves ), replacing the normal 380V AC three-phase power supply. Under low voltage power supply conditions, the controller controls the motor to slowly move to the leveled position. However, UPS and ARD costs are high, and battery power is limited. After several evacuation operations, the battery power will be almost completely used up.

2. The elevator car can be slid to the leveled position using a star-delta contactor. The three-phase motor winding is short-circuited by a star-delta contactor. The frequency converter is not functioning. The short circuit current of the motor can generate a torque resistance that is balanced with the load torque, so that the elevator car can move to the adjacent aligned position at low speed. After receiving the leveled zone signal or the door area signal, the pulley brake is quickly closed to stop the elevator car in the leveled position. This method can prevent the cost of power supply from UPS and ARD, but the sliding speed of the elevator car provided by the star-delta contactor is low, so it takes a long time to return to the leveled position. In addition, the pulley brake works when the speed of the elevator is not zero, which has a negative effect on passengers.

3. The sliding of the elevator car can be performed by an electrical device. This method has the same principle as the star-delta contactor. However, the three-phase motor winding is short-circuited by the inverter switches, not by the star-delta mechanical contactor. Therefore, the same problems as described above take place here.

4. In this circuit, the energy regeneration of the motor is determined. In patent document CN107128756A, a scheme has been presented in which, when three-phase input power is unavailable during the movement of the elevator, the control strategy in the motor is changed to generate renewable energy in order to maintain direct current (DC) voltage in the bus and return the elevator car to the leveled position in a smooth and controlled manner. way. However, this scheme is implemented before the DC bus voltage has fallen to a low level, and it does not provide how you can return the elevator car to the leveled position in a smooth manner when the elevator has already stopped moving and the DC bus voltage has already dropped. down to zero.

5. The elevator car can slide by blocking the PWM wave of the frequency converter. When the elevator controller detects that there is a failure of the elevator and it has stopped without power supply, the inverter PWM wave is blocked and the pulley brake is released to allow the motor to slide. At this time, the inverter runs in an uncontrolled rectification state, and the regenerated energy of the motor charges the DC bus through the IGBT flyback diode. When the DC bus voltage rises to a predetermined threshold or the motor slip reaches a predetermined speed, the elevator controller starts switching to closed-loop motor speed control, and then controls the elevator car to smoothly return to the leveled position. The problem with this scheme is that when it starts, the sliding speed is too high, which has a negative effect on passengers.

In conclusion, there are certain problems in prior art solutions such as high costs, poor convenience, or DC bus voltage too low to operate in the event of a mains failure.

DISCLOSURE OF THE INVENTION

It is an object of the present application to present a method and system for evacuating an elevator and a controller that addresses the above problems of prior art solutions such as high costs, poor convenience, or DC bus voltage too low to operate in the event of a power failure.

In one aspect, a method for evacuating an elevator is provided, which includes:

switching the power source from the primary power source to the backup power source, switching the motor to a short circuit state, and ensuring that the elevator car enters the car slip state when it is detected that the primary power source is unavailable,

releasing a short circuit state of the motor and performing open-loop control on the motor after the elevator car enters the car sliding state for a predetermined time so that the inverter module outputs voltage to the motor according to a predetermined strategy; wherein the motor uses the power generated by the cab sliding operation to charge the power storage component on the high power DC bus after detecting the voltage applied by the inverter module;

performing closed-loop control on the engine upon detecting that the engine enters a predetermined steady state so that the engine speed reaches a predetermined escape speed and the engine operates according to the predetermined escape speed;

reducing the engine speed to zero and stopping the engine based on closed-loop control, and then stopping the sliding of the car so that the elevator car stops at the leveled position and the elevator car door is opened when it is detected that the elevator car has moved a predetermined distance from an aligned position.

In the second aspect, a controller is presented that contains:

a car sliding control unit configured to switch the power source from the primary power source to the backup power source, switch the motor to a short circuit state, and ensure that the elevator car enters the car sliding state when it detects that the primary power source is unavailable,

an open-loop control unit that is configured to clear the motor short-circuit condition and perform open-loop control on the motor after the elevator car enters the car sliding state for a predetermined time so that the inverter module applies voltage to the motor according to a predetermined a certain strategy; wherein the motor uses the power generated by sliding the cabin to charge the power storage component on the high power DC bus after detecting the voltage applied by the inverter module;

a closed-loop control unit that is configured to perform closed-loop control on the engine upon detecting that the engine enters a predetermined steady state so that the engine speed reaches a predetermined evacuation speed and the engine operates in accordance with a predetermined evacuation speed;

a brake control unit which is configured to reduce the engine rotation speed to zero and stop the engine based on closed-loop control, and then stop the car sliding operation so that the elevator car stops in a leveled position and the elevator car door is opened, upon detecting that that the elevator car moves a predetermined distance from the leveled position.

In a third aspect, a controller is provided that includes a memory and a processor, the memory being configured to store a computer program that can be executed by the processor, wherein the execution of the computer program by the processor takes place in the steps of the above-described elevator evacuation method.

In a fourth aspect, an elevator evacuation system is provided that includes a rectifier module, a high power DC bus, an inverter module, a buck converter, a switch, a backup power supply, a DC/DC converter, and a controller as described above; wherein the rectifier module, the high power DC bus, and the inverter module are connected in series;

a buck converter is connected to the high power DC bus to lower the high power DC bus voltage and output a reduced power DC bus voltage;

the backup power supply is connected to the buck converter to capture power from the buck converter for charging under normal power supply;

the switch is connected to the buck converter, the backup power supply, the controller, and the DC/DC converter, respectively, to select at least one DC output source from the buck converter and the backup power supply under the control of the controller;

The DC/DC converter comprises an input port and a plurality of output ports, wherein the input port is connected to a switch, and the plurality of output ports, respectively, is connected to an inverter module, a controller, and other devices associated with the movement of an elevator, to realize the voltage conversion of a DC output source. current selected by the switch, and outputting the operating voltage to the inverter module, controller and other devices related to the movement of the elevator.

By implementing the method and system for evacuating an elevator and the controller according to the present application, several advantages can be achieved. In the present invention, the motor is switched to a short circuit state before the elevator car slip is activated, so that the car slip can start at a low speed to ensure that the elevator car does not accelerate quickly, thereby improving the stability and safety of starting during an evacuation operation. After that, open-loop control is implemented, followed by closed-loop control. Negative voltage is applied to the motor through open loop control so that the motor can charge the high power DC bus to improve smooth switching to closed loop control. Closed-loop control enables the motor to start more smoothly during the return to leveling process, and when stopped, the motor speed can be quickly reduced to zero based on closed-loop control. In this way, the feeling of hopelessness caused by the direct closing of the pulley brake will be eliminated, and the convenience and stability of the evacuation process can be improved. In summary, in the present application, there is no need to provide a UPS or ARD, and the hardware cost is low, while the elevator can realize stable start, return to level and stop control when the primary power source is not available and the DC bus voltage drops. to a very low value or even to zero.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly describe the embodiment of the present invention or the prior art, the following description will briefly describe the drawings used in the embodiment or the prior art. Obviously, the following drawings represent only embodiments of the present invention. A person skilled in the art, without any creative effort, will also be able to obtain drawings other than the drawings shown.

Fig. 1 is a schematic representation of the operation of an elevator.

Fig. 2 is a diagram of an elevator evacuation method according to the first embodiment of the present invention.

Fig. 3 is a diagram of an elevator evacuation method according to the second embodiment of the present invention.

Fig. 4 is a structural diagram of a controller according to the third embodiment of the present invention.

Fig. 5 is a structural diagram of a controller according to the fourth embodiment of the present invention.

Fig. 6 is a diagram of an elevator evacuation system according to a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to facilitate understanding of the present invention, a more comprehensive description of the present invention will now be presented with reference to the corresponding drawings. Typical embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are presented in order to make the description more detailed and exhaustive.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally known to a person skilled in the art to which the present invention pertains. The terms used in the description of the present invention are presented for the purpose of describing particular embodiments only and are not intended to limit the present invention.

Fig. 1 is a schematic representation of the operation of an elevator according to the present application. As shown, the AC output from the three-phase power supply is converted to DC after being rectified by the rectifier module, and then output to the inverter module via the high power DC bus. Then, the inverter module converts the direct current into an adjustable voltage alternating current to control the speed of the motor and drive the elevator car to move up and down by the motor. On the one hand, the controller controls the inverter module to control the operation of the motor, and on the other hand, it controls other parts of the elevator operation, such as the pulley brake, etc.

The general idea of the present invention is as follows. First, upon detecting that the primary power supply is unavailable, the power supply switches from the primary power supply to the backup power supply, and the motor switches to a short circuit state, and the elevator car enters the car sliding state. Then, after the elevator car enters the car sliding state for a predetermined time, the motor short-circuit condition is released and open-loop control is performed on the motor so that the inverter module can apply voltage to the motor according to a predetermined strategy. The motor uses the energy generated by the cab sliding to charge the energy storage component on the high power DC bus after detecting the voltage applied by the inverter module. When the engine is detected to enter a predetermined steady state, closed-loop control is performed on the engine so that the engine rotation speed reaches the predetermined evacuation speed and the engine operates in accordance with the predetermined evacuation speed. Finally, upon detecting that the elevator car has moved a predetermined distance from the leveled position, the motor rotation speed is reduced to zero, and then the engine is stopped based on closed-loop control, then the car sliding is stopped, so that the elevator car stops at the leveled position, and the elevator door opens.

In order to provide an improved understanding of the above technical solutions, they will be described in detail in conjunction with the description drawings and specific implementation methods. It should be understood that the specific features of the embodiments and embodiments of the present invention are a detailed description of the technical solutions of the present application, and not a limitation of the technical solutions of the present application. In case there is no conflict, embodiments and technical features in an embodiment of the present invention can be combined with each other.

First implementation option

Fig. 2 is a diagram of an elevator evacuation method according to the first embodiment of the present invention. The method is executed by the controller in FIG. 1, and a detailed description of the implementation process of the method is as follows.

In step S101, upon detecting that the primary power supply is unavailable, the power supply switches from the primary power supply to the backup power supply, and the motor switches to a short circuit state, and the elevator car enters the car sliding state.

Turning the motor into a short circuit state means that the motor enters the signal blocking state. For example, all the bridge high-side switches in the inverter module connected to the motor are turned off, and all the bridge low-side switches in the inverter module are turned on at the same time, so that the signal lock state of the motor is realized electronically.

The steps of the method in this embodiment may be implemented by the controller in FIG. 1 when interacting with other devices related to motor movement (such as inverter module, pulley brake, etc.). Therefore, when the primary power supply is not available, a power supply must also be provided for the controller and other devices associated with the movement of the elevator. Thus, in this embodiment, when the primary power source is available, the backup power source and devices associated with the movement of the elevator grab power from the DC bus at high power for charging or operation after a voltage drop. When the primary power source is not available, the power source is switched from the primary power source to the backup power source, so that the devices associated with the movement of the elevator take power, respectively, from the backup power source for movement. For example, a low power DC bus is generally provided in the elevator system and is powered directly from the backup power source during an emergency evacuation, and the backup power source is charged by the high power DC bus when the primary power source is available. Thus, as the elevator system returns to normal operation within a certain period of time, it can be ensured that the backup power supply has enough power for the next evacuation.

In step S102, after the elevator car enters the car sliding state for a predetermined time, the motor short circuit condition is released and open-loop control is performed on the motor so that the inverter module can apply voltage to the motor according to a predetermined strategy. The motor uses the energy generated by the cab sliding to charge the energy storage component on the high power DC bus after detecting the voltage applied by the inverter module.

In particular, the output voltage of the inverter module can be controlled to make the motor power negative (for example, if the direction of the voltage applied by the inverter module is opposite to the direction of the motor current, the motor power may be negative). Negative motor power means that the energy generated by the motor during slip is transferred to the high power DC bus.

In step S103, upon detecting that the engine has entered a predetermined steady state, closed-loop control is performed on the engine so that the engine speed reaches the predetermined evacuation speed and the engine runs according to the predetermined evacuation speed.

Since changing the high power DC bus power storage component by the motor in step S102 will increase the high power DC bus output voltage, smooth switching can be ensured when switching this step to open loop control. This is because if the high power DC bus does not have enough output voltage, but directly switches to closed loop control, there is a possibility that the controller output will be strong due to the bus voltage being too low, resulting in loss of control.

In step S104, upon detecting that the elevator car has moved a predetermined distance from the leveled position, the rotation speed of the engine is reduced to zero, and then the engine is stopped on the basis of closed-loop control, then the sliding of the car is stopped, so that the elevator car stops in the leveled position. position and the elevator door opens.

In this embodiment, the motor is switched to a short circuit state before the activation of the elevator car slip, so that the car slip can start at a low speed to ensure that the elevator car does not accelerate quickly, thereby improving stability and start safety during the evacuation operation. After that, open-loop control is implemented, followed by closed-loop control. The negative voltage is supplied to the motor through open loop control so that the motor can charge the high power DC bus to boost the high power DC bus voltage and improve smooth switching to closed loop control. Closed-loop control enables the motor to start more smoothly during the return to leveling process, and when stopped, the motor speed can be quickly reduced to zero based on closed-loop control. In this way, the feeling of hopelessness caused by the direct closing of the pulley brake will be eliminated, and the convenience and stability of the evacuation process can be improved. In summary, in the present application, there is no need to provide a UPS or ARD, and the hardware cost is low, while the elevator car can realize stable start, return to level and stop control when the primary power supply is unavailable and the DC bus voltage drops to a very low value or even to zero.

Second implementation option

When the primary power supply is available, the backup power supply (such as a battery) and devices associated with the movement of the elevator (such as an inverter module, pulley brake, etc.) take power from the DC bus with high power to charge or operate after voltage reduction. When the primary power supply is unavailable, the elevator system will first report a failure and stop, and at this time, the motor will stop until the maintenance personnel manually or the high-level control software automatically starts the implementation of the evacuation method shown in FIG. 3 of this embodiment. Similarly, the method is executed by the controller in FIG. one.

In step S201, the power supply is switched from the primary power supply to the backup power supply, the devices associated with the movement of the elevator take power, respectively, from the backup power supply. This can be implemented by switching the low power DC bus input to a redundant power supply via the controller.

In step S202, a check is made as to whether the evacuation conditions are satisfied; if so, the method proceeds to step S203, otherwise, the pulley brake is closed and the output of the inverter module is blocked to wait for manual evacuation.

The evacuation conditions include that the standby power supply condition is stable and the inverter module connected to the motor is working without fail. Here, steady state of the standby power supply means that the output voltage of the standby power supply is within the normal operating range.

In step S203, the motor is switched to the short circuit state by the inverter module. For example, the high side switches of the inverter module bridge are turned off, while the low side switches of the inverter module bridge are turned on. In this case, the switches of the upper and lower arms of the bridge are insulated gate bipolar transistors (IGBTs).

In step S204, the pulley brake is released so that the elevator car can enter the car sliding state. This can be done by controlling the pulley brake contactor to be activated by the controller.

In step S205, when the elevator car has entered the car sliding state for a predetermined time, the motor short circuit condition is released and open-loop control is performed on the motor so that the inverter module applies voltage to the motor according to a predetermined strategy; wherein the motor utilizes the power generated by the sliding of the car to charge the power storage component on the high power DC bus after detecting the voltage applied by the inverter module.

Preferably, the control of the inverter unit is performed to supply a voltage uq to the q-axis of the motor and a voltage ud to the d-axis of the motor; the voltage ud is 0. When the maximum output voltage Umax of the high power DC bus is less than αRsIq, the voltage uq is –Umax. When the maximum output voltage Umax of the high power DC bus is greater than or equal to αRsIq, the voltage uq is equal to –αRsIq. Wherein, Rs is the motor stator resistance, Iq is the real-time detectable q-axis component of the three-phase motor current, and α is a coefficient which is preferably less than 0.5.

In step S206, upon detecting that the engine has entered a predetermined steady state, closed-loop control is performed on the engine so that the engine speed reaches the predetermined escape speed and the engine runs according to the predetermined escape speed.

When the motor is in the cabin sliding state, the permanent magnet of the motor rotates to generate a counter electromotive force in the motor stator winding. Under the combined action of the voltage uq applied to the motor, a current is generated in the stator winding. The torque generated by this current can prevent the cab sliding speed provided by the motor from continuing to increase. The higher the sliding speed of the car provided by the motor, the greater the opposing electromotive force, the generated stator current, and the greater the torque. Thus, the acceleration of the sliding speed of the cabin is reduced, and even the sliding speed of the cabin can also be reduced. Finally, the stator torque and attractive force will reach equilibrium and the motor will reach a predetermined steady state. The predetermined steady state refers to the state where the motor speed and current remain stable. The so-called stability means that fluctuations in speed and current are within the allowable error range. The larger the above coefficient α, the higher the steady state speed of the motor. When the motor speed and current are kept stable, closed loop motor control can be selected, which includes the following steps.

In step S2061, after the motor speed and current have been kept stable, the motor switches from open-loop control to closed-loop control. During the switching process, the closed-loop speed, closed-loop torque current, and closed-loop excitation current for closed-loop control are initialized according to the current speed, motor current, and inverter module output during open-loop control. The specific process has the following aspects.

In the first aspect, the target speed for the closed-loop speed is set as the rotation speed returned by the motor at the switching time, and meanwhile, the closed-loop speed output value is set as the q-axis torque current at the switching time.

In the second aspect, the target torque current for the closed loop torque current is set as the q-axis torque current at the switching time, and meanwhile, the output value of the closed loop torque current is set as the voltage uq applied to q- motor axis by the inverter module at the last moment during open loop control.

In the third aspect, the set excitation current for the closed loop excitation current is set as the d-axis excitation current at the time of switching, and meanwhile, the output value of the closed-loop excitation current is set as the voltage ud applied to the d-axis of the motor by the inverter module at the last moment during open loop control.

Thus, when switching to closed-loop control, the set value and output value of the closed-loop control can be made to closely match the actual operating conditions, and seamless switching from open-loop control to closed-loop control can be realized.

In step S2062, the set speed for the closed loop speed is increased to the predetermined evacuation speed, the set torque current for the closed loop torque current is set as the closed loop speed output value, and the set drive current for the closed loop drive current is reduced down to zero.

Here, the increase to a predetermined evacuation speed and decrease to zero may be any increase or decrease modes according to a predetermined curve or a certain slope. There are no restrictions in this regard, so it can rise or fall along the entire line of travel.

When the set speed for closed loop speed rises to the predetermined evacuation speed, the final motor speed and current tend to be stable under closed loop control.

In step S207, upon detecting that the elevator car has moved a predetermined distance from the leveled position, the rotation speed of the engine is reduced to zero, and then the engine is stopped on the basis of closed-loop control, then the sliding of the car is stopped, so that the elevator car stops in the leveled position. position and the elevator door opens.

Specifically, in the car sliding process, when a door area signal or a leveled area signal is detected, it is detected that the elevator car and the leveled position are separated by a predetermined distance, and then the predetermined closed loop speed is modified to zero. When the rotation speed value returned by the motor is zero, the pulley brake is closed to stop the sliding of the car, and the elevator car door is opened.

Preferably, if the high power DC bus voltage is higher than the braking circuit start voltage in the above cabin sliding process in steps S210 to S207, the braking circuit is activated and the high voltage is absorbed through the braking resistor in the braking circuit.

In addition, the controller as a whole can be divided into a frequency controller and an elevator controller. The inverter controller, inverter module, and rectifier module in FIG. 1 form a frequency converter in the general sense. In the above cab sliding process including steps S201 to S207, if a fault is detected in the working environment of the inverter, the pulley brake is closed, the pulse width modulation (PWM) signal output to the inverter module is disabled, and the corresponding fault information is output.

In addition, in the above cabin sliding process including steps S201 to S207, if there is any failure affecting the operation of the engine, it is determined whether the number of times of entering the cabin sliding state exceeds a predetermined number of times of cabin sliding, for example, three times. If so, the sheave brake closes and all high and low bridge switches in the inverter module connected to the motor turn off to await evacuation. Otherwise, the motor switches to a short circuit state and the elevator car enters the car sliding state again.

Third implementation option

Referring to FIG. 4, the present embodiment discloses a controller based on the same concept. The controller contains:

a car sliding control unit configured to switch the power source from the primary power source to the backup power source, switch the motor to a short circuit state, and ensure that the elevator car enters the car sliding state when it detects that the primary power source is unavailable,

an open-loop control unit that is configured to clear the motor short-circuit condition and perform open-loop control on the motor after the elevator car enters the car sliding state for a predetermined time so that the inverter module applies voltage to the motor according to a predetermined a certain strategy; wherein the motor uses the power generated by sliding the cabin to charge the power storage component on the high power DC bus after detecting the voltage applied by the inverter module;

a closed-loop control unit that is configured to perform closed-loop control on the engine upon detecting that the engine enters a predetermined steady state so that the engine speed reaches a predetermined evacuation speed and the engine operates in accordance with a predetermined evacuation speed;

a brake control unit that is configured to reduce the engine rotation speed to zero and stop the engine based on closed loop control, and then stop the sliding of the car so that the elevator car stops in a leveled position and the elevator car door is opened, upon detecting that that the elevator car moves a predetermined distance from the leveled position.

In the preferred embodiment, the open loop control unit further comprises a high power DC bus that is configured to control the inverter module to supply a voltage uq to the q-axis of the motor and a voltage ud to the d-axis of the motor; wherein the voltage ud is equal to 0. When the maximum output voltage of the high power DC bus is less than αRsIq, the voltage uq is equal to the maximum output voltage of the high power DC bus. When the maximum high power DC bus output voltage is greater than or equal to αRsIq, the voltage uq is equal to –αRsIq. Wherein, Rs is the motor stator resistance, Iq is the real-time detectable q-axis component of the three-phase motor current, and α is a coefficient which is preferably less than 0.5.

In a preferred embodiment, the closed loop control unit further comprises:

a switching unit that is configured to switch the motor from open-loop control to closed-loop control after the motor speed and current are stable, wherein during the switching process, initialization of the closed-loop speed, closed-loop torque, and closed-loop excitation current loop for closed-loop control according to the current speed and current of the motor and inverter module output during open-loop control;

an adjusting unit that is configured to raise the closed loop speed command speed to a predetermined evacuation speed, set the closed loop torque current command torque current as the closed loop speed output, and decrease the field current command current for the field current closed loop to zero.

In a more preferred embodiment, the switching unit further comprises:

a closed-loop speed initialization unit, which is configured to set the target speed for the closed-loop speed as the rotation speed returned by the motor at the time of switching, and meanwhile, set the closed-loop speed output value as the q-axis torque current at the moment of switching;

a closed-loop torque current initialization unit, which is configured to set the target torque current for the closed-loop torque current as the q-axis torque current at the switching time, and meanwhile set the output value of the closed-loop torque current loop as the voltage uq applied to the q-axis of the motor by the inverter module at the last moment during open-loop control;

a closed-loop excitation current initialization unit, which is configured to set the predetermined excitation current for the closed-loop excitation current as a d-axis excitation current at the time of switching, and meanwhile, set the output value of the closed-loop excitation current as voltage ud applied to the d-axis of the motor by the inverter module at the last moment during open-loop control.

In a more preferred embodiment, the brake control unit further comprises:

a speed modification unit that is configured to modify the predetermined speed for the closed loop speed to zero upon detection of a door area or leveled zone signal;

a sheave brake and door control unit that is configured to close the sheave brake to interrupt car sliding to stop the elevator car in a leveled position and open the elevator car door when the rotation speed value returned by the motor is zero.

Other details may apply to the first and second embodiments, which will not be repeated here.

It should be noted that the above description includes various modules (and likewise blocks). Typically, these modules include hardware and/or a combination of hardware and software (eg, "frozen" (solidified) software). These modules may also include computer-readable storage media (such as non-volatile storage media) containing instructions (such as program instructions). When these instructions are executed by the processor, various functional features of the present invention may be performed. Therefore, the scope of this application is not limited to specific hardware and/or software features in modules that are explicitly specified in the implementation options, if not explicitly required. As a non-limiting example, program instructions (such as those stored in non-persistent memory and/or permanent memory) may be executed by one or more controllers.

Fourth implementation option

Referring to FIG. 5 and based on the same technical intent, the present embodiment discloses a controller that includes a memory and a processor, wherein the memory is configured to store a computer program that can be executed by the processor, wherein when the computer program is executed by the processor, the steps of the elevator evacuation method are implemented. described in the first and second embodiments.

Fifth implementation option

Referring to FIG. 6, the fifth embodiment discloses an elevator evacuation system comprising a rectifier module, a 540-570V high power DC bus, an inverter module, a buck converter, a switch, a backup power supply, a DC/DC converter, and a controller described in the third and fourth implementation options. The rectifier module, high power DC bus and inverter module are connected in series. The rectifier module rectifies the 3-phase power supply from the external power grid into DC voltage and injects it into the 540-570V high power DC bus. The inverter module converts the DC power in the high power DC bus into AC power and outputs the AC power to the controller controlled motor.

The buck converter is connected to the high power DC bus to step down the high power DC bus voltage and output the reduced voltage DC power.

The redundant power supply is connected to the buck converter to capture power from the buck converter for charging at normal power up.

The switch is connected to the buck converter, the backup power supply, the controller, and the DC/DC converter, respectively, to select one DC output source from the buck converter and the backup power supply under the control of the controller.

The DC/DC converter comprises an input port and a plurality of output ports, wherein the input port is connected to a switch, and the plurality of output ports, respectively, is connected to an inverter module, a controller, and other devices associated with the movement of an elevator, to realize the voltage conversion of a DC output source. current selected by the switch, and outputting the operating voltage to the inverter module, controller and other devices related to the movement of the elevator. For example, a DC/DC converter can perform voltage conversion on a DC output source selected by a switch to produce a DC output of 5V, 24V, ±15V.

In particular, in this embodiment, the backup power supply is a battery and the switch may be a relay. The common port of the relay is connected to the DC/DC converter via a 24V low power DC bus, the normally closed contact of the relay is connected to the buck converter, the normally open contact of the relay is connected to the battery, and the relay coil is connected to the controller.

It can be seen that the 24V low power DC bus is generally powered by the 540-570V high power DC bus after the voltage is reduced. For emergency evacuation, it is powered directly from the battery, which is charged by the 540-570 High Power DC Bus during normal operation. Thus, as the elevator system returns to normal operation within a certain period of time, it can be ensured that the battery has enough power for the next evacuation.

The particular evacuation process in the embodiment may refer to the first and fifth embodiments, which will not be repeated here.

In summary, by implementing the method and system for evacuating an elevator and the controller according to the present application, several advantages can be achieved. In the present invention, the motor is switched to a short circuit state before the elevator car slip is activated, so that the car slip can start at a low speed to ensure that the elevator car does not accelerate quickly, thereby improving stability and start safety during the evacuation operation. After that, open-loop control is implemented, followed by closed-loop control. Negative voltage is applied to the motor through open loop control so that the motor can charge the high power DC bus to improve smooth switching to closed loop control. Closed-loop control allows the motor to start more smoothly during the return to leveling process, and when stopped, the motor speed can be quickly reduced to zero based on closed-loop control. In this way, the feeling of hopelessness caused by the direct closing of the pulley brake will be eliminated, and the convenience and stability of the evacuation process can be improved. In summary, in the present application, there is no need to provide a UPS or ARD, and the hardware cost is low, while the elevator can realize stable start, return to level and stop control when the primary power source is not available and the DC bus voltage drops. to a very low value or even to zero.

Words such as "equals", "between" or other similar terms are not limited to absolute equality or identity of mathematical terms. When exercising the rights described in this application, they may be similar in design sense or within an acceptable range of error.

The above description refers to various elements. Typically, these blocks and modules include hardware and/or a combination of hardware and software (eg, "frozen" (solidified) software). It should be noted that in the above description of the various blocks, these blocks are separated only for the sake of clarity. However, in practice, the boundaries between different blocks may not be clear. Therefore, the scope of this application is not limited to mandatory boundaries between various hardware and/or software elements, unless expressly required otherwise.

An embodiment of the present invention has been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific embodiments mentioned above. The above specific implementation options are only schematic and not restrictive. One of ordinary skill in the art will be able to make many forms without departing from the scope protected by the object and claims of the present invention. All of them are included in the protection scope of the present invention.

Claims (49)

1. The method of evacuation of the elevator, including the following steps: switching the power source from the primary power source to the backup power source, switching the motor to a short circuit state, and ensuring that the elevator car enters the car slip state when it is detected that the primary power source is unavailable, releasing a short circuit state of the motor and performing open loop control on the motor after the elevator car enters the car sliding state for a predetermined time so that the inverter module applies voltage to the motor according to a predetermined strategy; wherein the motor charges the energy storage component on the high power DC bus with the energy generated by the car sliding after detecting the voltage applied by the inverter module; performing closed-loop control on the engine upon detecting that the engine enters a predetermined steady state so that the engine speed reaches a predetermined escape speed and the engine operates according to the predetermined escape speed; reducing the engine speed to zero and stopping the engine based on closed-loop control, and then stopping the sliding of the car so that the elevator car stops at the level position and the elevator car door is opened when it is detected that the elevator car has moved a predetermined distance from an aligned position. 2. The elevator evacuation method according to claim 1, wherein the step of performing open-loop control on the motor so that the inverter module applies voltage to the motor in accordance with a predetermined strategy further comprises: controlling the inverter module to supply voltage uq to the q-axis of the motor and voltage ud to the d-axis of the motor; in this case, the voltage ud is equal to 0; wherein when the maximum output voltage Umax of the high power DC bus is less than αRsIq, the voltage uq is -Umax; when the maximum output voltage Umax of the high power DC bus is greater than or equal to αRsIq, the voltage uq is equal to –αRsIq; where Rs is the motor stator resistance, Iq is the real-time detectable q-axis component of the three-phase motor current, and α is the coefficient. 3. The elevator evacuation method according to claim 1, wherein the step of executing closed loop control on the motor upon detecting that the motor has entered a predetermined steady state so that the rotational speed of the motor reaches a predetermined evacuation speed and the motor is running in accordance with a predetermined evacuation speed, additionally includes: switching the motor from open-loop control to closed-loop control, and initializing the closed-loop speed, closed-loop torque current, and closed-loop excitation current for closed-loop control according to the current speed and current of the motor, and the output of the inverter module when open-loop control during the switching process, after which the motor speed and current are kept stable; increasing the closed loop speed command speed to the escape speed preset, setting the closed loop torque current command torque as the closed loop speed output, and decreasing the closed loop field current field current command to zero. 4. The elevator evacuation method according to claim 3, characterized in that the step of initializing the closed-loop speed, the closed-loop torque current, and the closed-loop excitation current for closed-loop control according to the current speed and current of the motor and the output of the inverter module in open-loop control during the switching process, additionally includes: setting the target speed for the closed-loop speed as a rotation speed value returned by the motor at the switching time, and meanwhile setting the closed-loop speed output value as a q-axis torque current at the switching time; setting the torque reference current for the closed loop torque current as the q-axis torque current at the time of switching, and meanwhile setting the output value of the closed loop torque current as the voltage uq applied to the q-axis motor by the inverter module at the last torque during open loop control; setting the excitation target current for the closed loop excitation current as the d-axis excitation current at the time of switching, and meanwhile setting the output value of the closed-loop excitation current as the voltage ud applied to the d-axis of the motor by the inverter module at the last moment in the course of control with open loop. 5. The elevator evacuation method according to claim 1, characterized in that the step of reducing the engine rotation speed to zero and stopping the engine based on closed loop control, and then stopping the car sliding so that the elevator car stops in a leveled position and the elevator car door was opened, upon detecting that the elevator car has moved a predetermined distance from the leveled position, further includes: modifying the set speed for the closed loop speed to zero upon detection of a door area or leveled zone signal; and closing the pulley brake to interrupt the sliding of the car to stop the elevator car in a leveled position and open the elevator car door when the rotation speed value returned by the motor is zero. 6. The elevator evacuation method according to claim 1, characterized in that the step of switching the engine to a short circuit state and entering the elevator car into the car sliding state further includes: turning off all the switches of the upper bridge side in the inverter module and turning on all the switches of the lower side of the bridge in the inverter module, and then releasing the pulley brake to enter the elevator car into the car sliding state; moreover, the switches of the upper and lower arms of the bridge are insulated gate bipolar transistors. 7. The elevator evacuation method according to claim 1, which additionally includes: activating the braking circuit to absorb high voltage through the braking resistor in the braking circuit if the high power DC bus voltage during the cab sliding process is higher than the starting voltage of the braking circuit. 8. The elevator evacuation method according to claim 1, which additionally includes: closing the pulley brake, blocking the PWM signal output to the inverter module, and outputting the corresponding fault information if a fault is detected in the working environment of the frequency converter during the car sliding process. 9. The elevator evacuation method according to claim 1, which further includes: determining whether the number of car sliding state inputs exceeds a predetermined number of car sliding times, if any failure occurs in the car sliding process affecting engine operation, and if so, closing the pulley brake and turning off all the top and bottom switches bridge arms in the inverter module connected to the motor to wait for evacuation, otherwise, switching the motor to a short circuit state and allowing the elevator car to enter the car sliding state again. 10. The elevator evacuation method according to claim 1, which further includes: charging a backup power source and powering devices associated with the movement of the elevator, reduced voltage from the high power DC bus when the primary power source is available. 11. Controller, containing: a car sliding control unit configured to switch the power source from the primary power source to the backup power source, switch the motor to a short circuit state, and ensure that the elevator car enters the car sliding state when it detects that the primary power source is unavailable, an open-loop control unit that is configured to clear the motor short-circuit condition and perform open-loop control on the motor after the elevator car enters the car sliding state for a predetermined time so that the inverter module applies voltage to the motor according to a predetermined a certain strategy; wherein the motor charges the power storage component on the high power DC bus with the energy generated by the car sliding after detecting the voltage applied by the inverter module; a closed-loop control unit that is configured to perform closed-loop control on the engine upon detecting that the engine enters a predetermined steady state so that the engine speed reaches a predetermined evacuation speed and the engine operates in accordance with a predetermined evacuation speed; a brake control unit that is configured to reduce the engine speed to zero and stop the engine based on closed loop control and then stop the car sliding so that the elevator car stops in a level position and the elevator car door is opened, upon detecting that the elevator car moves a predetermined distance from the leveled position. 12. The controller according to claim 11, characterized in that the open loop control unit further comprises a high power DC bus charging unit, which is configured to control the inverter module to supply voltage uq to the q-axis of the motor and voltage ud to the d-axis engine; in this case, the voltage ud is equal to 0; wherein when the maximum output voltage Umax of the high power DC bus is less than αRsIq, the voltage uq is -Umax; when the maximum output voltage Umax of the high power DC bus is greater than or equal to αRsIq, the voltage uq is equal to –αRsIq; where Rs is the motor stator resistance, Iq is the real-time detectable q-axis component of the three-phase motor current, and α is the coefficient. 13. The controller according to claim 11, characterized in that the closed loop control unit further comprises: a switching unit that is configured to switch the motor from open-loop control to closed-loop control and initialize closed-loop speed, closed-loop torque current, and closed-loop excitation current for closed-loop control according to the current speed and current motor, and the output of the inverter module under open-loop control during the switching process, after which the motor speed and current are kept stable; an adjusting unit that is configured to increase the closed loop speed command speed to a predetermined evacuation speed, set the closed loop torque current command torque current as the closed loop speed output, and reduce the closed loop field current field current command contour to zero. 14. The controller according to claim 13, characterized in that the switching unit further comprises: a closed-loop speed initialization unit, which is configured to set the speed reference for the closed-loop speed as the value of the rotation speed returned by the motor at the time of switching, and meanwhile, set the closed-loop speed output value as the q-axis torque current in switching moment; a closed-loop torque current initialization unit, which is configured to set the predetermined torque current for the closed-loop torque current as a q-axis torque current at the switching time, and meanwhile, set the output value of the closed-loop torque current as the voltage uq applied to the q-axis of the motor by the inverter module at the last moment during open-loop control; a closed-loop excitation current initialization unit, which is configured to set a predetermined excitation current for the closed-loop excitation current as a d-axis excitation current at the switching time, and meanwhile, set an output value of the closed-loop excitation current as a voltage ud applied to d-axis motor by inverter module at the last moment during open-loop control. 15. The controller according to claim 11, characterized in that the brake control unit further comprises: a speed modification unit that is configured to modify the predetermined speed for the closed loop speed to zero upon detection of a door area or leveled area signal; a pulley brake and door control unit that is configured to close the pulley brake to interrupt the sliding of the car to stop the elevator car in a leveled position and open the elevator car door when the rotation speed value returned by the motor is zero. 16. A controller that contains a memory and a processor, wherein the memory is configured to store a computer program that can be executed by the processor, and when the computer program is executed by the processor, the steps of the elevator evacuation method according to any one of paragraphs are implemented. 1-10. 17. An elevator evacuation system that includes a rectifier module, a high power DC bus, an inverter module, a buck converter, a switch, a backup power supply, a DC/DC converter, and a controller according to any one of claims. 11-15; wherein the rectifier module, the high power DC bus, and the inverter module are connected in series; a buck converter is connected to the high power DC bus to lower the high power DC bus voltage and output a reduced voltage; the backup power supply is connected to the buck converter to capture power from the buck converter for charging under normal power supply; the switch is connected to the buck converter, the backup power supply, the controller, and the DC/DC converter, respectively, to select at least one DC output source from the buck converter and the backup power supply under the control of the controller; the DC-to-DC converter comprises an input port and a plurality of output ports, wherein the input port is connected to a switch, and the plurality of output ports are respectively connected to an inverter module, a controller and other devices associated with the movement of the elevator, to realize the voltage conversion of the DC output source, selected by the switch, and output the operating voltage to the inverter module, controller and other devices related to the movement of the elevator.

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