Transcript cc196880ad09e14x

Mechanical design of elevator

Our elevator :
Gen2 elevator :

Cables (Ropes) :
Cables connected from car over traction sheave, to counterweights
usually in groups of 3 to 8 ropes.
Multiple cables used to increase traction and safety factor.

There are two type of core :
1- Steel core
Steel core increase the metallic cross section and so reduce
the tensile strength in the individual wires.
2- Fiber core
The advantage of fiber core it's provides increase the
flexibility to the wire rope .
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the advanced ropes (used in GEN2 ):
The GEN2 flat coated steel belts
The pulse system :
RBI Device (Resistance Based inspection ) :
Pulse electronic monitoring:
1-Continuously monitoring the belt's
steel cords.
2-Reducing the down time.
3-Increasing the reliability of the
inspection.
 the unit is located at the top of
the hoistway , where it is connected
at the belt termination .
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Pulse system consists of :
a- The belt with cords b- Conducting pins
c- Detection leds
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Machine room:
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Machine roomless (In GEN2) :

Advantages and drawback of machine room less
Advantages
Drawback
Save space
Core dimensions different according
to manufacture.
Reduce energy consumption
Reduce motor size and weight
Reduce heat o/p
No machine room required
Installation requirement according to
manufacture.
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Geared machine:
Gearless machine :
In our project :
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In Gen2 :
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1.
2.
3.
Advantages of Gearless machines:
The machine is located at the top of hoistway, so
building
space is saved dramatically, which also making the
GeN2-Regen machine easier to install and less energy
to consume.
Gearless machine is as much as 50% more efficient than
a conventional geared machine.
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Suspension methods :
IN OUR PROJECT :
1:1 Gearless Overhead :

In GEN2 :
2:1 Gearless Overhead :
Comparison
Power
1:1
2:1
Higher power
lower power
P=(Wcw-Wc)*r*ω
P=0.5(Wcw-Wc)*r*ω
Cost of elevator
running
More expensive
Less expensive
Cost of method
components
Lower
Higher
Higher
Lower
Life time
Maintenance
Speed
less maintenance
Higher
More maintenance
Lower
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Overspeed :
Theory of the operation :

Tests :
1- Elevator pit test :
2-Elevator car tests :

Elevator machine room test :
How to convert the elevator machine to
regenerative mode?
Induction Machine squirrel (generator mode) n>ns.
Induction generator operating a lone (capacitor banks).
Induction generators (squirrel) limitations.
Induction machine as generator
Generator mode at n>ns
The induction machine will operate as a generator if its
stator
terminals are connected to a three-phase supply and its rotor
is driven above the synchronous speed.
Induction machine generating mode
(cont’d)
In our project
 generate power form IM squirrel cage (n>ns) using
inverter to decrease ns so n>ns can be reached for our
model
 The inverter should also provide reactive power for IM
 Then all conditions for generation are
 Satisfied
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Induction machine generating mode
(cont’d)
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Limitations:
After experimenting the previous method to meet these
conditions the generated power returning back from
the stator, the inverter rejected it displaying error .
The inverter was unidirectional which means that it
provided the power from the source to the motor BUT
in the reverse direction the generated power was
rejected by the inverter !!
Induction machine operating alone
 It is also possible for an induction machine to
function as an isolated generator as long as
capacitors are available to supply the reactive
power required by the generator and by any
attached loads
Induction machine operating alone
cont’d
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Limitations
In our project, in case of using capacitors building up
voltage at terminals
Will take time until reaching (operating point)
At that time the car will be already
In the ground floor
V
P
Operating point
t
Vt2
Vt1
Vtr
IC
0 IC1 IC2
Voltage buildup
Permanent Magnet motors
Why PM ??
Construction of PMSM and BLDC
Theory of operation of PMSM and BLDC
Comparison between PMSM and BLDC
PM motors in regeneration
Why PM ??
The use of permanent magnets (PMs) in construction of electrical
machines brings the following benefits:
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1- high efficiency because there is excitation losses
2-high power and torque densities
3-better dynamic performance
4-simpilicty in construction and maintenance
5-reduction in prices for some types of machines
Construction of PMSM and BLDC
 PMSM and BLDC motors
 Both (typically) have permanent-magnet
rotor and a
wound stator
 So PMSM and BLDC have the same construction
Theory of operation of PMSM and
BLDC
 for BLDC
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in BLDC motors Current is being switched from winding to
winding
Using electronic commutation unlike mechanical commutation in
DC motors.
how does the motor know when to switch
current, or commutate?
Position determination and logic circuitry
Theory of operation of PMSM and
BLDC
PMSM
 PMSM has the same construction and
theory of operation like BLDC

Comparison between PMSM and
BLDC
Although PMSM and BLDC motors are similar
in construction and in the theory of operation
there is a significant difference between them
back emf of the BLDC motor is trapezoidal but
in PMSM it is sinusoidal
 Also BLDC is fed by DC current but in PMSM is
fed by AC current
Only two phases are on in BLDC at the same time
while it Is possible for PMSM to have 3 phases on
at the same time.

PM motors in regeneration
C
A specific version of the Green Power PM
gearless machine prepared to work at 28 AC
will be used
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Simulate the permanent magnet by
DC field rotor
Synchronous generator
 Synchronous motor drawbacks
 Induction wound rotor as generator
(doubly fed)
 Our project idea and implementation
 Experiments
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Synchronous generator
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Synchronous machine is the most popular machine in
generators
So when thinking about regeneration elevators we have to
consider synchronous generator as an option
Theory of operation
In Synchronous Generator, a DC current is applied to rotor
winding (produce rotor magnetic field).
The rotor is turned by prime mover producing a rotating
magnetic field.
The rotating magnetic field produce three phase sets of
voltages within the stator.
• Armature winding [in stator]
• Field winding [in rotor]
Synchronous motor
Theory
Applying DC current field to the rotor and
three phase balanced current is applied to
the winding of the stator then the rotor
poles will be locked to the stator opposite
poles and it will run with synchronous
speed.
Why synchronous motor is not
suitable ?
1- DC excitation must be applied to the
rotor
 2-Not self starting
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Why synchronous motor is not
suitable ? Cont’d
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3- The cost per kW output is generally higher than that of
induction motors
4- no possibility of speed adjustment unless the incoming
supply frequency is adjusted (Variable Frequency Drives)
5- Synchronous motors cannot be started on load. Its
starting torque is zero
6-When loading increase the synchronism will be lost and
the motor will halt.
7-collector and brushes mean more maintenance
8- not suitable for high starting torque applications
9- tendency to hunt
induction motor wound rotor as
generator(doubly-fed induction
generator)
induction motor wound rotor as
generator(doubly-fed induction
generator)
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When the stator and the rotor magnetic
fields rotate in the same direction
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When the stator and the rotor magnetic
fields rotate in the opposite direction
induction motor wound rotor as generator(doublyfed induction generator)
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The frequency f-rotor of the ac currents that
need to be fed into the doubly-fed induction
generator rotor windings to maintain the
generator output frequency f-stator the
same value as the frequency f-network of
the ac power network depends on the
rotation speed of the generator rotor nrotor and can be calculated using the
following equation
induction motor wound rotor as
generator(doubly-fed induction
generator)
Our project main idea
Our project main idea
we use the induction motor wound rotor as
generator by fed the rotor by dc current to
simulate the permanent magnet synchronous
machine which the best machine suitable to our
application so we use special case of the doubly
fed
 Rotor connection for motoring mode:
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Our project main idea cont’d
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Rotor connection for generating mode:
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Note that the stator connection can be star or delta
but practically we found that we need the delta
connection to be able to run the elevator at low
frequencies.
Experiment
Objective:
 Finding relation between the applied
frequency to the rotor and the output
voltage.
 Connection
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Experiment cont’d
Steps
 DC supply voltage = 134V
 Vrotor = 5V DC
 Irotor = 5A
 Change the frequency of the prime mover
using IC5
 Draw relation between the frequency of
the prime mover and the generator
output voltage
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Experiment cont’d
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Results
Frequency
(Hz)
Line output voltage (V)
1
12:65
1.5
30:54
2
30:55.5
2.5
22:66
3
25:70
3.5
35:68
4
40:55
Experiment cont’d
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Relation between output voltage and
frequency
Experiment cont’d
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Using Simulink
Experiment cont’d
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Results
Final search cont’d
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Company Contacts
Company name: PRIMA TRADING (SUZHOU) CO.,LTD
Tel: 86-512-5286-2628; 5286-2658; 5284-2226
Fax: 86-512-52862566
Add: Rm. 304 Zhongjiang Business Center
,No.2 Kaiyuan Avenue.,Changshu Jiangsu 215500,P.R.China
Email: [email protected]
Website: www.primatrading.com.cn

Final search
Final search cont’d
The company has the driver for this machine but
note that it’s not regenerative drive so you need
to look for regenerative drive if you need its
application
 Because of the high costs of the PMSM and its
driver we looked for another idea to can achieve
our project practically. We made this study to
choose the suitable machine for our application
as long as we don’t have the PMSM. We need a
machine to operate in motoring and generating
modes

Why we use drive system in our project ?
*Drive System is considered the brain of the motor to
controlling the rotational speed of the motor by
controlling the frequency and voltage of the electric
power supplied to the motor.
Types of drives
1. DC drives:
To drive DC motors.
(series, shunt, separately excited).
1. AC drives:
To drive AC motors.
(induction, synchronous).
Construction of the drive system?
*Any drive system consist of three main parts as shown :
1. RECTIFIRE PART
*Convert the incoming AC voltage into DC voltage by using any
techniques as half wave rectifier or full wave rectifier.
2. DC BUS PART
*It`s holding capacitor that`s store the dc value come from the
converter part on it`s terminals in order not to have ripples and it
feed the inverter part.
3. INVERTER PART
*Takes the electrical energy from the DC link and supply it to the
motor after convert it to AC voltage, and it`s consist of 6
switches of any types of the power electronics element (IGBT,
Mosfet, SCR) , and it`s use certain sequence for (on-off) each
element to have building up AC voltage feed to the motor.
The main types of inverter
*The inverters can be classified into two types they are:
1.Voltage Source Inverter (VSI)
* When the DC voltage remains constant (i.e, low-ripple) This 
is achieved with a capacitor or LC filter in the dc link, then it
is called voltage source inverter(VSI) or voltage fed inverter
(VFI).
*When the DC voltage remains constant (i.e., low-ripple) This is achieved
with a capacitor or LC filter in the dc link, then it is called voltage
source inverter(VSI) or voltage fed inverter (VFI).
2.Current Source Inverter (CSI)
*When the input current remains constant this is
achieved with a series inductor is placed in the dc link.
then it is called current source inverter (CSI) or current
fed inverter (CFI).
IG5 in our project
Three modes of operation:
Motoring mode 
Generation mode 
Power cut mode 
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Ac drive
220-230 (3-phase i/p)
1HP
con1
con3
3 phase
IM
rectifier
con2
battery
Types of drives based on power flow
*Where as the types of drives based on the direction of
power flow divided into two types.
1. Non Re-generative drives
*The diode is one direction transmission unit. The power
transferred from potential energy produce can not feed back to
the building grid. These energy have to be consumed by resistance
heating.
2.Re-generative drives
Introduction
*any industrial application are usually characterized by
power flow that goes from the ac distribution system to
the load.
*For example (elevator) in case of motoring mode
operation (fig2) the active power flows from the source
side to motor side.
*However, in which the load may supply power to the
system. This is known as the regenerative mode
operation (fig1).
Electrical power
Consumption
loaded car
Electrical power
Generation
loaded car
Lightly car
Lightly car
Fig1
fig2
*hence we can say that the drives operates in the motoring mode
when the power flows from the source to the motor side, and in the
regenerative mode when the power flows from the motor side
to the source side.
*Also this type of drives called(Bi-directional inverter) as
shown in the fig.
1) Motoring mode operation
* in this mode the inverter in the left side at the grid side is used
as bridge converter by using the freewheeling diodes (FWD) to
convert from ac to dc which are can be made smooth due to the
capacitor used between 2 sides.
*and the transistors (IGBT) will be (open circuit).
* while the inverter in the right side at the motor side is used to
convert from dc to ac by using transistors (IGBT) in order to supply
the motor in normal operation.
*and the (FWD) will be (open circuit).
Motoring mode operation cont.
Motoring mode operation cont.
Waves form in Motoring mode.
2) Re-generative mode operation:
*in this mode the inverter in the right side at the motor side is
used as bridge converter by using the freewheeling diodes
(FWD) to convert from regenerated ac to dc which are can be
made smooth due to the capacitor used between 2 sides .
*and the transistors (IGBT) will be (open circuit).
*while the inverter in the left side at the grid side is used to
convert from dc to ac using transistors (IGBT) and return the
power back to the grid.
*and the (FWD) will be (open circuit).
Re-generative mode operation cont.
*We can return the power in three ways:1- to dynamic resistor.
2-to batteries in dc bus.
3-to supply grid.
1- to dynamic resistor or batteries
(AC single phase)
3-to supply grid.
*First method
3-to supply grid cont.
*second method
Waves form in Re-generative mode
Re-generative mode operation cont.
conclusion
Non Re-Generative drive = Energy wasted
+
Dynamic Braking Resistors
Cooling
Re-Generative drive = Energy Re-used in many different applications
And the Energy saving will be up to 70%
Motoring Mode
Power cut mode
Generating mode
Flow chart of three modes
Moving between floors in six categories
Start
Determine car floor
Floor 1
Floor 0
Call
1
Call
2
Call
0
Floor 2
Call
2
Motoring Mode
Call
0
Call
1
Operating in Forward direction
Floor 0
Constant
speed
operation
Floor 1
Floor 2
A
Motoring Mode
Floor 0
Call
2
N
A
o
A
yes
Door
contacts
=1
Over
weight
No
Set brakes ,con_1 and con_2
Move in forward direction
Power
cut
No
Slow
signal
Operate at low speed
Continue
yes
Activate ARD
Magnet 3
Magnet 4
Magnet 3
Proximity _slow
Magnet 2
Magnet 2
Proximity stop
Magnet 1
Magnet 1
Motoring Mode
Continue
yes
Power
cut
Activate ARD
No
Stop
Signal
No
Reset brakes . Energize door
lock 2 relay
Floor 2
Operate at low speed
Floor 2
Generation Mode
Call 0
Full
load car
No
Set brakes
Set Contactor 3 and DC relay
Stop
signal
Stop Motor
Reset Contactor 3 and DC relay
Floor 0
Motoring Mode
Power cut mode
Power
cut
Move in forward direction
Set Contactor 1 and 2
Time
out
Stop Motor reset contactor 1,2
and brakes and store I fow in D00
Move in reverse direction
Set Contactor 1 and 2
Time
out
Stop Motor reset contactor 1,2
and brakes and store I rev in D01
Compare I fow and
I rev
Continue
Continue
Power cut mode
I fow > I
rev
No
Operate inForward
direction , set contactor
1 , 2 and brakes
No
Stop signal
Yes
Reset brakes . Energize door
lock
Reset Contactor 1 and 2
Operate in Reverse
direction , set contactor
1 , 2 and brakes
Quick review
Call buttons
Contactors
Limit Switch
Proximity sensor
Door lock -fb
Indicator o/p
Power check
relay
Door contact
Door lock
relays
PLC
Master relay
Master
K120-S
Brakes relay
DC relay
Drives control
pins
FX
PLC
Master
K120-S
RX
P1
U
V
W
Ac Drives
IG5
CM
inputs
Induction Motor wound
rotor