The most famous technique for starting of synchronous motor is to use an Amortisseur winding, it also is known as damper A pole face with a set of damper winding is shown in given figure. Using pony motors 2. The interaction of the fluxes produces torque in the direction of field rotation. Otherwise, instead of merely coasting along, the pony would act as an electric brake and draw unnecessary power from the idler. Below are the techniques used for starting a synchronous motor: Starting a Synchronous Motor Using an Induction Motor. It is generated by the torque applied to the motor shaft at the beginning of the starting. However, there are also great disadvantages: It offers no adjustable starting characteristics and a soft stop is not possible at all. Pony motor method Synchronous Motor Starting Methods. Synchronous motor can started by the following three methods: 1. MY old D7's are much older requiring a hand crank start - but -30 was no problem- you fill gas tank on pony- pull decompression lever & put pony tranny in lo & let it crank till there is good oil pressure- then compression till pony runs out of gas-- refill tank- put pony tranny in hi & let it run a bit then hit the fuel to diesel & presto - you are off & running- the big eng is all Bryan Parker sells kits that convert most Caterpillar engines equipped with a pony motor to electric start. A small (also called as a pony) Ac induction motor will be connected with the synchronous motor. the second method of starting a synchronous motor is to attach an external starting motor (pony motor) to it and bring the synchronous machine to near about its rated speed (but not exactly equal to it, as the synchronization process may fail to indicate the point of closure of the main switch connecting the synchronous machine to the supply Usually the objective is to maintain the motor below 90% heating. We need to bring the rotor of the synchronous motor to synchronous speed before we switch on the motor.
Depending on the starting method and the motor and application parameters, heating during start can be 40-90%. Using small d.c. machine coupled to it. Also, high torque and current peaks during the switchover are possible. As the motor requires six wires, the cable costs are not to be underestimated. This method is based on the principle that in star connections, the voltage across each winding is phase voltage i.e. The stator winding is initially connected in a star configuration and later on changed over to a Delta connection, when the motor reaches rated speed. The various methods to start the synchronous motor are, 1. Using damper windings. Pony Motor Starting Method. In other words, the motor is started as an induction motor, the bars in the pole face slots forming a sort of squirrel cage rotor. Willy said, Today, in 1983, to rebuild a Caterpillar pony motor, costs around $6000.00 and the parts were now obsolete, and difficult to find.. Once started, the pony was "clutched" into the primary enginethe diesel..and, in turn, the diesel was set in motiona parasite upon the pony until the diesel actually began combustion. Therefore, it requires some auxiliary means of starting. on starting method selection. Mechanical stress is the third consequence of the motor start. This tuning method is designed to be performed with the idler running but with no electrical load. Heat from the pony motor helped the diesel attain starting temperature. A. Multiple steps required Overvoltages Special control (motor speed) Not suited for Islanded systems Motor Starting Problems (3) steps (i.e. 3xCB) 51 Motor Starting Pony Motor (not Jacking Motor) The method used for starting synchronous motor is/are - Published on 29 Oct 15. a. Note here, that the number of poles Idler is a 1750 RPM and Pony is 3600 RPM. StarDelta starters for large motors. The 3 Star Delta Starting Methods of Induction Motor. As a slip ring induction motor 4. Using Pony Motors : By using the small pony motors like a small induction motor, we can start the synchronous motor. The engines must have gear reducers of at least 10 to 1. As seen earlier, synchronous motor is not self starting. A synchronous motor is not inherently self-starting. It is necessary to rotate the rotor at a speed very near to synchronous speed. Reviews starting techniques for AC motors: direct-on-line, captive transformer, autotransformer, capacitor start, wye-delta, solid-state soft start, Adjustable Drive System (ASD), pony driver starting, and adjustable V/f isolated bus starting. This is possible by various method in practice. As a result, the rotor of the motor will pull into step with the stator magnetic field. Its stator winding which consists of a 3 phase winding is provided with 3 phase supply and rotor is provided with DC supply. Answer (1 of 20): Principle of Operation Synchronous Motor Synchronous motor is a doubly excited machine i.e two electrical inputs are provided to it. Three-Point Starting Method: The starter used is basically a variable resistance divided into a number of sections.
8 years ago. An induction motor or pony motor Pony Motor starting Here left side motor indicate induction motor and right side motor indicate synchronous motor. The small engine used for a "pony motor" was typically gasoline powered. Methods Of Starting Synchronous Motor 1. Pony Starting Engine Rope Length. The motor gets synchronized, and then supply to the pony motor is disconnected. For understanding in a given figure, the salient pole rotor with having 2 poles consists of damper windings is shown. Using pony motors. Synchronous Motor Starting with an External Prime Mover They sell for as little as $595 to as much as $885, depending on the kit. Grigg Any constructive on topic ideas please share. The cost is as little as $895 or as much as $1,200 depending on which options you choose with the kit. The methods are given below: 1. When the motor picks up the speed, the DC excitation to the rotor is turned on. We also have charging systems. This is primarily where using a pull to start small (gasoline) engine is more practical (for various reasons) than battery powered electric starters or stored air pressure pneumatic starters. Using pony motors 2. Starting methods of Induction motor include: Direct On line (DOL) starters for less than 10 Kw motors. Induction Motor Start. My recommendations are for D2-4 - 7 feet, and D6 - 10 feet of 1/4" diameter polypropylene sash cord with a minimum tensile strength of 250 lbs. Get a 6 or 8 inch tire and wheel and merry it to the output shaft of the engine. This small induction motor is coupled to the rotor of the synchronous motor. Allowing for a one button start pony started converter.
Convert Cat Engines From Pony Motor To Electric Start ENGINES Engines 90-10-48 Bryan Parker sells kits that convert most Caterpillar engines equipped with a pony motor to electric start. The cost is as little as $895 or as much as $1,200 depending on which options you choose with the kit. Starting using variable frequency External prime mover. Answer (1 of 2): I can add to Kevins answer; the small starting engine used to get started a larger engine. Make a base on a hinge affair with a tiller to tilt the engine into the flywheel. 1. Pony Motor Method / Induction Motor Pony motors are small motors mostly induction motors,which are used to run the rotor near to the synchronous speed. However, the pony motor starting method is not a common practice for induction motor, it requires additional equipment including pony motor, 415V VFD for the pony motor and MV Panel with Capacitor Bank. Got in touch with ICM folks and they said it will start up with just L1 and 2, but just have to set the interrogation period long enough for L3 to be generated. It works as a three-phase induction motor. In this method, an external motor is coupled mechanically to the synchronous motor. This information is from a Caterpillar Technical Partsgram issued in May 1966. When a three phase supply is connected to the stator, the synchronous motor with Damper Winding will start. Some options were considered only in passing and others were investigated more thoroughly as follows: 1) Auxiliary Starting Motors (Diesel or electric): One option considered was to install pony motors to Using damper winding 3. A motor is an electro-mechanical device which converts electrical energy to mechanical energy. Synchronous Motor Working Principle. A soft starter or reduced voltage starter for the 330kw would probably be less expensive than installing a separate pony motor with an additional starter, wiring, and installation costs. We've helped hundreds of FARM SHOW readers convert Cat engines from pony motor to electric start using our do-it-yourself kits. [1]. Procedure to start a synchronous motor Reduced voltage is given to the stator terminals of the synchronous motor, with the help of an autotransformer. External prime mover 2. The VFD for a pony motor is not the simplest method for making this type of converter, but in this case seems like a good idea to me, and it can be programmed to also control the electric cluthc and teh contactor on the 40HP. A. and a 3 phase motor runs at. New for 2001 is a kit to convert Cat generators to a 1-wire alternator. Damper winding 3. In this method, a small induction motor known as pony motor is used to bring the motor speed to synchronous speed. The Top Common Four Starting Methods of DC Motor. We now have kits for the RD-6 3 cylinder. Using damper winding 3. However, as mentioned by scottyuk, a pony motor would work and does make sense on larger motors and at higher voltages. The function of this induction motor is to bring the rotor of the synchronous motor to the synchronous speed. The pony motor start-run capacitor is disconnected whenever the idler is running. As soon as the motor approaches the synchronous speed, the DC excitation is applied to the field windings. The kits are available for both 12 and 24-volt electric systems. In this thread, member Skogsgurra related a novel method employed to soft start 11kv synchronous motors using a 690v feed into a 3300V, 250KVA transformer, using a VFD to slowly bring up the speed on a defibrator at a pulp mill. Damper windings, consisting of copper bronze bars embedded in slots in the pole faces and short-circuited at both ends are usually provided in synchronous motors which serve not only to damp out oscillations during hunting but are also suitably designed as a squirrel-cage winding for starting purposes. He said customers that owned Caterpillar diesel bulldozers were all so happy to be able For that reason, we directly couple a small induction motor (pony motor) with the synchronous motor. In order to start a synchronous motor, there are following two methods . After the speed has reached up to its synchronous value, the DC field is switched ON. In the previous article we came to know that synchronous motors are not self starting so to make them start. Some of these engines have 3 or 4 to 1 reduction which is too fast to use to start a big engine. The most common synchronous motor starting methods are: Supply frequency control Using an external motor Small pony motors DC motors Slip ring Induction motor Damper windings Let us discuss these induction motor starting methods in a bit more detail. 1/3 times the line voltage whereas the same winding, when connected in delta, will have full line voltage across it. The synchronous motor runs along with the Induction motor initially. When 3-phase supply is fed to the stator, a rotating magnetic field is produced in the air gap which induces currents in the bars which further produces flux. Have a 1 way sprag clutch on the pony motor and Pony has a 3" pulley while idler has a 6" pulley. Starting with damper windings. Motor Starting Alternatives Considered Multiple motor starting alternatives were considered to address the voltage flicker limits. Starting with an external prime mover. Auto transformer. The contact points of these sections are called studs starting from the OFF position to the RUN position with many resistances within these positions. The method used for starting synchronous motors are using pony motors, damper windings. Equivalent circuit for start and operation. This is possible through various methods in practice. By using the small pony motors like a small induction motor, we can start the synchronous motor. This small induction motor is coupled to the rotor of the synchronous motor. The function of this induction motor is to bring the rotor of the synchronous motor to the synchronous speed. b. As a slip ring induction motor 4. Home >> Category >> Electrical Engineering (MCQ) questions and answers >> Electrical Machines; Q. Supply frequency control Supply frequency control to start synchronous motor This motor is not self starting it requires some additional devices to start the motor.