Elevator traction machine definition
The traction machine is the main source of power for moving the elevator cabinet. Its mission is to convert electrical energy into power.
Classification of elevator traction machines
Classified by the type of voltage supplied by the motor on the traction machine
DC motor traction machine
AC motor traction machine
Classification by shifting system
1: Geared traction machine
2: Gearless traction machine
Geared traction machine
2: spur gear,
3: helical gear,
4: Planetary gear
Elevator gearless traction machine
Gearless traction machine classification
1: DC traction machine
2: AC permanent magnet synchronous traction machine
3: AC linear motor traction machine (Otis D25)
Structure of elevator traction machine
The structure of the elevator with gear elevator traction machine includes
1: motor (DC motor, AC motor)
2: reduction gearbox, traction sheave (spur gear, helical gear, turbine, planetary gear)
3: Brake wheel, brake (external hub brake brake shoe, internal brake brake shoe, disc brake)
4: Encoder (incremental encoder)
5: brake switch (mechanical switch, photoelectric sensor switch, Hall sensor)
6: traction machine thermal protection (thermal switch, PTC thermistor, NTC thermistor)
Gearless elevator traction machine structure
1: motor (DC motor, AC motor, AC linear motor)
2: Brake wheel, brake (external hub brake brake shoe, internal brake brake shoe, disc brake)
3: Encoder (positive cosine, absolute encoder)
4: brake switch (mechanical switch, photoelectric sensor switch, Hall sensor)
5: Motor thermal protection (thermal switch, PTC thermistor, NTC thermistor)
Elevator traction machine thermal protection
The elevator traction machine is thermally protected. In order to protect the traction machine from being burnt due to overcurrent or overvoltage heating, a thermistor is inserted into the stator winding of the traction machine, or a thermal switch is attached to the stator core. When the motor is heated due to peripheral control or its own internal fault temperature, the thermal element will work, cut off the control, and then stop the motor.
1: Thermal switch, the thermal switch is usually normally closed, that is, when the temperature rises to a certain temperature, the moving contact piece is broken due to heat bending.
2: Thermistors have two types of thermal elements, PTC and NTC.
When the temperature rises, the resistance of the PTC thermistor increases with the increase in temperature.
When the temperature of the NTC thermistor increases, its resistance decreases with increasing temperature.
Elevator brake (brake brake)
The brakes of the elevator motor are divided into mechanical brakes and electrical brakes.
The electric brake of the elevator motor is divided into eddy current braking and energy consumption braking.
Eddy current brakes are commonly used in AC variable resistance elevators (two-speed elevators)
Energy consumption braking, in the AC voltage regulating elevator, in the elevator braking process, DC current is applied to control the speed of the elevator, and the current of the applied DC current is reduced to reduce the running speed of the motor (OTIS TOEC40, Mitsubishi ACVV, Schindler MB ~D2)
VVVF drive and energy brake
In today's permanent magnet synchronous traction machine driven system, VVVF drive is adopted. In the deceleration braking of the motor, in order to stably control the voltage on the DC bus (BUS), the DC bus (BUS) is used. The brake unit is set up (the collector of the IGBT is connected in series with the high-power resistor across the P and N of the BUS)
Elevator traction machine mechanical brake (brake)
The brake of the elevator consists of an electromagnetic brake coil, a brake arm linkage assembly and a brake shoe. When the elevator is running, the brake is released. When the elevator stops, the brake shoe is locked on the brake wheel (zero speed closing), and the deceleration of the elevator is not implemented by the mechanical brake.
Brake (brake) detection switch
The setting of the brake switch is to detect the reliability of the mechanical action of the brake during the start and stop of the elevator. The action of the mechanical brake accurately transmits the signal to the control system through the on/off of the switch, so that the system makes a correct judgment. Similarly, the brake switch is also a sub-unit of the elevator safety protection.
REGEN Energy Regeneration System
In the latest system of inverter-driven permanent magnet synchronous motor with energy feedback, the mechanical energy of the negative load operation is converted into electric energy, which is not released by the brake unit, but is directly fed back to the grid, which will be more environmentally friendly and energy-saving. The OTIS REGEN system and the LIHY-II/III both use an energy regeneration system.
The speed encoder is used to detect the speed at which the motor is running. It is also the selector of the elevator.
When the elevator is running, the square wave pulse from the speed encoder, the inverter control unit counts the pulse, senses the speed of the elevator, and simultaneously outputs a series of pulse codes through the frequency divider card of the frequency converter, and cooperates with the leveling sensor. After self-learning through the well, the floor table is compiled in the software, and the actual position of the elevator in the hoistway is reflected. The selection of the elevator is realized by the floor table in the system.
The HEIDENHAIN 1387 encoder is widely used in today's permanent magnet synchronous masters. It is a standard sine and cosine encoder. The data setting type on the Westway inverter is SINCOSSIN, which has an incremental channel and a sine and cosine signal channel. The output, the incremental pulse is 2048/rev, and the working voltage is 5V+- 5%. In the configuration of Xiwei inverter, the initial setting of the magnetic phase angle is required. This must be done after the elevator has been commissioned and the encoder has been replaced.
The application of the absolute encoder on the permanent magnet synchronous traction machine does not require the encoder phase angle compensation learning due to the particularity of the output signal.
Definition of traction machine\motor nameplate data
TYPE: 160VAT_OVF motor form: 160VAT - for Otis frequency conversion,
PART NO: TAA2003C153 Part Number: TAA2003C153
SUPPLIER: REIVAJ supplier: REIVAJ, Spain
SERVIAL NO: 7215090 Serial number: 7215090
Motor supply line voltage
AC 380/415 V 50/60HZ
AC 380/415 V 50/60 Hz
Pulse width modulation speed regulation is to change the DC voltage pulse width applied to the rotor or stator end of the motor through the on/off of the electronic switch when the DC power supply voltage is substantially constant. (the so-called duty cycle), to adjust the voltage average of the input motor rotor or stator
Inverter drives PWM common mode
In the vector control, due to peripheral environmental defects and loop interference, the common mode suppression circuit is designed in the PWM output of the inverter. Due to the increase of the common mode voltage, the PWM vector closed-loop control of the inverter will increase the output voltage accordingly. This will cause the voltage of the traction motor to be too high and burn out. In addition, the design adds a filter to the circuit and requires the motor power line to shield.
Note: In order to control the voltage rise of the PWM output, the power line length of the inverter to the motor is usually less than 5 meters.