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. 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. Pulse system consists of : a- The belt with cords b- Conducting pins c- Detection leds Machine room: Machine roomless (In GEN2) : Advantages and drawback of machine room less Advantages Save space Reduce energy consumption Reduce motor size and weight Reduce heat o/p No machine room required Drawback Core dimensions different according to manufacture. Installation requirement according to manufacture. Geared machine: Gearless machine : In our project : In Gen2 : Advantages of Gearless machines: 1. The machine is located at the top of hoistway, so building 2. space is saved dramatically, which also making the GeN2-Regen machine easier to install and less energy to consume. 3. Gearless machine is as much as 50% more efficient than a conventional geared machine. Suspension methods : IN OUR PROJECT : 1:1 Gearless Overhead : In GEN2 : 2:1 Gearless Overhead : 2:11:1Comparison lower power P=0.5(Wcw-Wc)*r* Higher power P=(Wcw-Wc)*r* Power Less expensiveMore expensive Cost of elevator running Higher Lower Cost of method components LowerHigherLife time More maintenanceless maintenanceMaintenance LowerHigherSpeed 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 (contd) 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 Induction machine generating mode (contd) 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 contd 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 VtVt ICIC V tr V t1 V t2 I C1 I C2 0 P Voltage buildup Operating point 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: 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 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 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 Synchronous generator 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 Why synchronous motor is not suitable ? Contd 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) When the stator and the rotor magnetic fields rotate in the same direction When the stator and the rotor magnetic fields rotate in the opposite direction induction motor wound rotor as generator(doubly- fed induction generator) 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 n- rotor and can be calculated using the following equation induction motor wound rotor as generator(doubly-fed induction generator) 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: Our project main idea contd Rotor connection for generating mode: 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 Experiment contd Steps DC supply voltage = 134V V rotor = 5V DC I rotor = 5A Change the frequency of the prime mover using IC5 Draw relation between the frequency of the prime mover and the generator output voltage Experiment contd Results Frequency (Hz) Line output voltage (V) 112: :54 230: :66 325: :68 440:55 Experiment contd Relation between output voltage and frequency Experiment contd Using Simulink Experiment contd Results Final search contd Company Contacts Company name: PRIMA TRADING (SUZHOU) CO.,LTD Tel: ; ; Fax: Add: Rm. 304 Zhongjiang Business Center,No.2 Kaiyuan Avenue.,Changshu Jiangsu ,P.R.China Website: Final search Final search contd The company has the driver for this machine but note that its 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 dont have the PMSM. We need a machine to operate in motoring and generating modes Why we use drive system in our project ? brain *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 Types of drives DC 1. DC drives: To drive DC motors..(series, shunt, separately excited) AC 1. AC drives: To drive AC motors..(induction, synchronous) Construction of the drive system? three as shown : *Any drive system consist of three main parts 1. RECTIFIRE PART DC voltage *Convert the incoming AC voltage into DC voltage by using any techniques as half wave rectifier or full wave rectifier. 2. DC BUS PART holding capacitor *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 AC voltage *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 two *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). DC voltage remains constant capacitor LC filter *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) input current remains constant a series inductor *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 Ac drive (3-phase i/p) 1HP 3 phase IM rectifier battery con1 con2 con3 Types of drives based on power flow two *Where as the types of drives based on the direction of power flow divided into two types. 1. Non Re-generative drives one direction not feed back *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 (elevator) motoring mode *For example (elevator) in case of motoring mode operation (fig2) the active power flows from the source side to motor side. regenerative mode *However, in which the load may supply power to the system. This is known as the regenerative mode operation (fig1). Fig1 fig2 Fig1 fig2 loaded loaded car Lightly Lightly car Generation Electrical power Generation loaded loaded car Lightly Lightly car Consumption Electrical power Consumption motoring mode regenerative mode *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 inverter in the left side * 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. (IGBT) (open circuit). *and the transistors (IGBT) will be (open circuit). inverter in the right side * 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. (FWD) (open circuit). *and the (FWD) will be (open circuit). Motoring mode operation cont. Waves form in Motoring mode. 2) Re-generative mode operation: inverter in the right side *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. (IGBT)(open circuit) *and the transistors (IGBT) will be (open circuit). inverter in the left side *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. (FWD) (open circuit) *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 80 + Dynamic Braking Resistors Cooling Non Re-Generative drive = Energy wasted Re-Generative drive = Energy Re-used in many different applications And the Energy saving will be up to 70% Power cut mode Generating mode Motoring Mode Flow chart of three modes Start Determine car floor Floor 0 Floor 2 Floor 1 Call 2 Call 1 Call 0 Call 1 Call 0 Moving between floors in six categories Motoring Mode Constant speed operation Operating in Forward direction Floor 0 Floor 1 Floor 2 Floor 0 Call 2 Door contacts =1 Over weight NoNo A A A Set brakes,con_1 and con_2 Move in forward direction Power cut No Activate ARD yes Slow signal No Operate at low speed Continue yes Motoring Mode Magnet 4 Magnet 3 Magnet 2 Magnet 1 Magnet 2 Magnet 3 Proximity stop Proximity _slow Continue Power cut Activate ARD yes No Stop Signal Operate at low speed No Reset brakes. Energize door lock 2 relay Floor 2 Motoring Mode Generation Mode Floor 2 Call 0 Full load car Motoring Mode No Set brakes Set Contactor 3 and DC relay Stop signal Stop Motor Reset Contactor 3 and DC relay Floor 0 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 Power cut mode Continue I fow > I rev Operate in Reverse direction, set contactor 1, 2 and brakes Reset brakes. Energize door lock Reset Contactor 1 and 2 No Operate inForward direction, set contactor 1, 2 and brakes Stop signal No Yes Limit Switch Indicator o/p Power check relay Master relay Brakes relay DC relay Drives control pins PLC Master K120-S Call buttons Proximity sensor Door lock -fb Door contact Contactors Door lock relays Quick review PLC Master K120-S PLC Master K120-S FX RX P1 CM Ac Drives IG5 U V W Induction Motor wound rotor inputs