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67-398: The Kawasaki Heavy Industries & CSR Qingdao Sifang C151A is the fourth generation electric multiple unit rolling stock in operation on the existing North–South (NSL) and East–West (EWL) lines of Singapore's Mass Rapid Transit (MRT) system, manufactured by Kawasaki Heavy Industries (KHI) and CRRC Qingdao Sifang under Contract 151A. Their introduction to the network has increased

134-537: A phase converter having single-phase converter input and three-phase inverter output. Controller advances have exploited dramatic increases in the voltage and current ratings and switching frequency of solid-state power devices over the past six decades. Introduced in 1983, the insulated-gate bipolar transistor (IGBT) has in the past two decades come to dominate VFDs as an inverter switching device. In variable- torque applications suited for Volts-per-Hertz (V/Hz) drive control, AC motor characteristics require that

201-817: A CaiXin Online article originally published in March 2016 by the China Railway Construction Corporation blaming the China Railway Rolling Stock Corporation for the decline of quality standards. According to the former, 60% of all railway incidents in China and 90% of all railway disruptions during 2015 can be attributed to CRRC manufactured trains not meeting quality or maintenance standards, with 210 instances resulting in death or injuries. The equivalent of

268-510: A Hong Kong-based non-profit news organization FactWire had broken the news of the C151A trains suffering from multiple defects relating to Chinese-made materials and posted the entire investigative works in YouTube . These are the list of allegations mentioned in their YouTube video since C151A entered into revenue service in 2011 (27 May 2011). This list compiles the initial response from

335-557: A VFD system is usually a three-phase induction motor . Some types of single-phase motors or synchronous motors can be advantageous in some situations, but generally three-phase induction motors are preferred as the most economical. Motors that are designed for fixed-speed operation are often used. Elevated-voltage stresses imposed on induction motors that are supplied by VFDs require that such motors be designed for definite-purpose inverter-fed duty in accordance with such requirements as Part 31 of NEMA Standard MG-1. The VFD controller

402-440: A VFD, the stopping sequence is just the opposite as the starting sequence. The frequency and voltage applied to the motor are ramped down at a controlled rate. When the frequency approaches zero, the motor is shut off. A small amount of braking torque is available to help decelerate the load a little faster than it would stop if the motor were simply switched off and allowed to coast. Additional braking torque can be obtained by adding

469-621: A braking circuit (resistor controlled by a transistor) to dissipate the braking energy. With a four-quadrant rectifier (active front-end), the VFD is able to brake the load by applying a reverse torque and injecting the energy back to the AC line. Many fixed-speed motor load applications that are supplied direct from AC line power can save energy when they are operated at variable speed by means of VFD. Such energy cost savings are especially pronounced in variable-torque centrifugal fan and pump applications, where

536-409: A conveyor application for smoother deceleration and acceleration control, which reduces the backlash that can occur when a conveyor is accelerating or decelerating. Performance factors tending to favor the use of DC drives over AC drives include such requirements as continuous operation at low speed, four-quadrant operation with regeneration, frequent acceleration and deceleration routines, and need for

603-417: A maximum output of 140 kW (190 hp). However, the main difference is that the traction for the trains is higher pitched than the ones from C751B trains which are lower pitched. The C151A trains use the monolink axlebox type bolsterless air spring bogie. There are no major technical differences between a trailer and motor car bogie other than additional electrical components for the latter; similar to

670-497: A means for an operator to start and stop the motor and adjust the operating speed. The VFD may also be controlled by a programmable logic controller through Modbus or another similar interface. Additional operator control functions might include reversing, and switching between manual speed adjustment and automatic control from an external process control signal. The operator interface often includes an alphanumeric display or indication lights and meters to provide information about

737-411: A motor) that controls speed and torque by varying the frequency of the input electricity. Depending on its topology , it controls the associated voltage or current variation. VFDs are used in applications ranging from small appliances to large compressors. Systems using VFDs can be more efficient than hydraulic systems , such as in systems with pumps and damper control for fans. Since

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804-483: A motor-driving car or power-driving car. On third rail systems, the outer vehicles usually carry the pick up shoes with the motor vehicles receiving the current via intra-unit connections . Many modern two-car EMU sets are set up as twin or "married pair" units. While both units in a married pair are typically driving motors, the ancillary equipment (air compressor and tanks, batteries and charging equipment, traction power and control equipment, etc.) are shared between

871-406: A pure electrical means of communication. Typical means of hardwired communication are: 4-20mA , 0-10VDC, or using the internal 24VDC power supply with a potentiometer . Speed can also be controlled remotely and locally. Remote control instructs the VFD to ignore speed commands from the keypad while local control instructs the VFD to ignore external control and only abide by the keypad. Depending on

938-534: A step-up transformer is placed between a LV drive and a MV motor load. MV drives are typically rated for motor applications greater than between about 375 and 750 kW (503 and 1,006 hp). MV drives have historically required considerably more application design effort than required for LV drive applications. The power rating of MV drives can reach 100 MW (130,000 hp), a range of different drive topologies being involved for different rating, performance, power quality, and reliability requirements. It

1005-436: A wide range of single-phase and multi-phase AC motors. Low-voltage (LV) drives are designed to operate at output voltages equal to or less than 690 V. While motor-application LV drives are available in ratings of up to the order of 5 or 6 MW, economic considerations typically favor medium-voltage (MV) drives with much lower power ratings. Different MV drive topologies (see Table 2) are configured in accordance with

1072-546: Is a solid-state power electronics conversion system consisting of three distinct sub-systems: a rectifier bridge converter, a direct current (DC) link, and an inverter. Voltage-source inverter (VSI) drives (see 'Generic topologies' sub-section below) are by far the most common type of drives. Most drives are AC–AC drives in that they convert AC line input to AC inverter output. However, in some applications such as common DC bus or solar applications, drives are configured as DC–AC drives. The most basic rectifier converter for

1139-400: Is also often available to allow the VFD to be configured, adjusted, monitored, and controlled using a computer. There are two main ways to control the speed of a VFD; networked or hardwired. Networked involves transmitting the intended speed over a communication protocol such as Modbus , Modbus / TCP , EtherNet/IP , or via a keypad using Display Serial Interface while hardwired involves

1206-596: Is constructed from intersections of a saw-toothed carrier signal with a modulating sinusoidal signal which is variable in operating frequency as well as in voltage (or current). Operation of the motors above rated nameplate speed (base speed) is possible, but is limited to conditions that do not require more power than the nameplate rating of the motor. This is sometimes called "field weakening" and, for AC motors, means operating at less than rated V/Hz and above rated nameplate speed. Permanent magnet synchronous motors have quite limited field-weakening speed range due to

1273-414: Is drawing less than 50% of its rated current from the mains in the low-speed range. A VFD can be adjusted to produce a steady 150% starting torque from standstill right up to full speed. However, motor cooling deteriorates and can result in overheating as speed decreases such that prolonged low-speed operation with significant torque is not usually possible without separately motorized fan ventilation. With

1340-443: Is estimated that drive technology is adopted in as many as 30–40% of all newly installed motors. An energy consumption breakdown of the global population of AC motor installations is as shown in the following table: AC drives are used to bring about process and quality improvements in industrial and commercial applications' acceleration, flow, monitoring, pressure, speed, temperature, tension, and torque. Fixed-speed loads subject

1407-412: Is regarded as the inventor of this technology. Strömberg managed to sell the idea of PWM drive to Helsinki Metro in 1973 and in 1982 the first PWM drive SAMI10 were operational. A variable-frequency drive is a device used in a drive system consisting of the following three main sub-systems: AC motor, main drive controller assembly, and drive/operator interface. The AC electric motor used in

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1474-417: Is simpler as no provision is needed for exhausting fumes, although retrofitting existing limited-clearance tunnels to accommodate the extra equipment needed to transmit electric power to the train can be difficult. Multiple unit train control was first used in the 1890s. The Liverpool Overhead Railway opened in 1893 with two-car electric multiple units, controllers in cabs at both ends directly controlling

1541-727: The China Railway High-speed in China, ICE 3 in Germany, and the British Rail class 395 Javelin. The retired New York–Washington Metroliner service, first operated by the Pennsylvania Railroad and later by Amtrak , also featured high-speed electric multiple-unit cars, known as the Budd Metroliner . EMUs powered by fuel cells are under development. If successful, this would avoid

1608-551: The Land Transport Authority (LTA) and SMRT for the cover-up about the defective trains, while others questioned the quality of the Chinese-made trains. The LTA released more technical details on 6 July 2016 claiming that 5 of the 26 defective trains had been rectified, including photos illustrating the 'hair-line crack'. The authority also named an independent third-party assessor, TUV Rheinland who shared

1675-520: The 1980s, power electronics technology has reduced VFD cost and size and has improved performance through advances in semiconductor switching devices, drive topologies, simulation and control techniques, and control hardware and software. VFDs include low- and medium-voltage AC–AC and DC–AC topologies. Pulse-Width Modulating (PWM) variable-frequency drive projects started in the 1960s at Strömberg in Finland. Martti Harmoinen  [ fi ]

1742-499: The C751B trains. A break from tradition, the C151A trains features auxiliary inverters for its electrical systems on all six cars of the train. Previously, auxiliary inverters were mounted only on motor cars. The VVVF Inverter is controlled by IGBT semiconductors and rated at 80 kV. A battery charger is built with the inverter and provides 16 kW (21 hp) output. The interior of the C151A trains depending on each car, features

1809-567: The English article is also provided by CaiXin Online as well. The incident became a political issue as opposition politician Gerald Giam from the Workers' Party questioned the transport authority for awarding the consortium a "top quality score", among other statements in his Facebook page. The party later issued a second statement that their MPs would file 17 questions in Parliament about

1876-568: The North–South Line during the MRT disruption in 2011, starting from 7 May 2012 all the way until 23 October 2013. SMRT engineers detected arcing problems on one of the C151As, but no evidence was shown that it was the root cause of the service suspension in 2015. During the suspension of the C151A running on the North–South Line, SMRT had investigated and found impurities in aluminium bodywork caused

1943-463: The United States, an estimated 60–65% of electrical energy is used to supply motors, 75% of which are variable-torque fan, pump, and compressor loads. Eighteen percent of the energy used in the 40 million motors in the U.S. could be saved by efficient energy improvement technologies such as VFDs. Only about 3% of the total installed base of AC motors are provided with AC drives. However, it

2010-426: The VFD controller. Basic programming of the microprocessor is provided as user-inaccessible firmware . User programming of display , variable, and function block parameters is provided to control, protect, and monitor the VFD, motor, and driven equipment. The basic drive controller can be configured to selectively include such optional power components and accessories as follows: The operator interface provides

2077-722: The VSI drive is configured as a three-phase, six-pulse, full-wave diode bridge . In a VSI drive, the DC link consists of a capacitor which smooths out the converter's DC output ripple and provides a stiff input to the inverter. This filtered DC voltage is converted to quasi- sinusoidal AC voltage output using the inverter's active switching elements. VSI drives provide higher power factor and lower harmonic distortion than phase-controlled current-source inverter (CSI) and load-commutated inverter (LCI) drives (see 'Generic topologies' sub-section below). The drive controller can also be configured as

Kawasaki Heavy Industries & CSR Qingdao Sifang C151A - Misplaced Pages Continue

2144-471: The allegations in a press statement. The link to the original rumor was deleted soon after the response from the authorities. On 7 July 2016, the LTA also stated that "no brackets were added at any time to the underframe" in order to refute a subsequent FactWire report claim. LTA also stated that it "considered that the contractor was able to quickly identify the cause of the defects, take responsibility and carry out

2211-492: The authorities are compiled from the first SMRT press release on 5 July 2016, 4:30pm (GMT+8) by SMRT Trains managing director Lee Ling Wee as well as the first Land Transport Authority press release at an hour after first SMRT's press release. and also the subsequent official position on Singapore government's online FAQ portal 'Factually' which quotes sources from the Facebook page of Land Transport Authority hours after

2278-445: The batteries are charged via the electric pickup when operating on electric mode. EMUs, when compared with electric locomotives , offer: Electric locomotives, when compared to EMUs, offer: VVVF A variable-frequency drive ( VFD , or adjustable-frequency drive , adjustable-speed drive , variable-speed drive , AC drive , micro drive , inverter drive , or drive ) is a type of AC motor drive (system incorporating

2345-649: The capacity of both lines by 15%. They are the last batch of rolling stock on the two lines to be painted in the "Blackbird" livery. Developed from the Kawasaki Heavy Industries & Nippon Sharyo C751B trainsets, further developments of the type include the C151B and C151C trains featuring design updates and changes. The C151A was the first rolling stock on the MRT network to be manufactured in China . The initial contract of 22 trainsets of 6 cars each

2412-544: The chart's four quadrants are defined as follows: Most applications involve single-quadrant loads operating in quadrant I, such as in variable-torque (e.g. centrifugal pumps or fans) and certain constant-torque (e.g. extruders) loads. Certain applications involve two-quadrant loads operating in quadrant I and II where the speed is positive but the torque changes polarity as in case of a fan decelerating faster than natural mechanical losses. Some sources define two-quadrant drives as loads operating in quadrants I and III where

2479-430: The constant magnet flux linkage . Wound-rotor synchronous motors and induction motors have much wider speed range. For example, a 100 HP, 460 V, 60 Hz, 1775  RPM (4-pole) induction motor supplied with 460 V, 75 Hz (6.134 V/Hz), would be limited to 60/75 = 80% torque at 125% speed (2218.75 RPM) = 100% power. At higher speeds, the induction motor torque has to be limited further due to

2546-485: The construction of electric traction railways and trolley systems worldwide. Each car of the train has its own traction motors: by means of motor control relays in each car energized by train-line wires from the front car all of the traction motors in the train are controlled in unison. The cars that form a complete EMU set can usually be separated by function into four types: power car, motor car, driving car, and trailer car. Each car can have more than one function, such as

2613-427: The contactor thus turns on the drive and has it output to a designated speed. Depending on the sophistication of the drive multiple auto-starting behavior can be developed e.g. the drive auto-starts on power up but does not auto-start from clearing an emergency stop until a reset has been cycled. Referring to the accompanying chart, drive applications can be categorized as single-quadrant, two-quadrant, or four-quadrant;

2680-477: The cracks found in structural components, including the sub-floor, which is a compartment located under passenger floor. Its role is to hold equipment box and electrical wires and bolster function parts connecting the car body to the bogie. Affected trainsets were sent back to China progressively between July 2014 and January 2020, before the COVID-19 pandemic . The tender for trains under the contract turnkey 151A

2747-488: The first being when 2 C151 trains collided at Clementi . Electric multiple unit EMUs are popular on commuter, and suburban rail networks around the world due to their fast acceleration and pollution-free operation, and are used on most rapid-transit systems. Being quieter than diesel multiple units (DMUs) and locomotive -hauled trains, EMUs can operate later at night and more frequently without disturbing nearby residents. In addition, tunnel design for EMU trains

Kawasaki Heavy Industries & CSR Qingdao Sifang C151A - Misplaced Pages Continue

2814-547: The initial press release. Moreover, an unnamed source from CRRC Qingdao Sifang claimed to FactWire that since 2015, 5 or more affected trains have already been replaced. This source claims that the entire process to rectify the issue will take 4 months to complete. This 4 months process begins with shipping the trains from Singapore to Qingdao , getting the defective train disassembled before parts are to reassembled into new aluminium train car body manufactured by Kawasaki Heavy Industries as well as testing and ending it with

2881-431: The issue. On 12 July 2016, Transport Minister Khaw Boon Wan released an extensive statement about this issue. These are the key points that Khaw have made: On 15 November 2017 at approximately 8.18am, 2 C151A trains collided at Joo Koon MRT station . 29 passengers were conveyed to various hospitals following the incident and a further 7 walked in themselves. This is the second of such incidents after 5 August 1993, with

2948-420: The load's torque and power vary with the square and cube , respectively, of the speed. This change gives a large power reduction compared to fixed-speed operation for a relatively small reduction in speed. For example, at 63% speed a motor load consumes only 25% of its full-speed power. This reduction is in accordance with affinity laws that define the relationship between various centrifugal load variables. In

3015-418: The lowering of the breakaway torque of the motor. Thus, rated power can be typically produced only up to 130–150% of the rated nameplate speed. Wound-rotor synchronous motors can be run at even higher speeds. In rolling mill drives, often 200–300% of the base speed is used. The mechanical strength of the rotor limits the maximum speed of the motor. An embedded microprocessor governs the overall operation of

3082-433: The model a VFD's operating parameters can be programmed via: dedicated programming software, internal keypad, external keypad, or SD card. VFDs will often block out most programming changes while running. Typical parameters that need to be set include: motor nameplate information, speed reference source, on/off control source and braking control. It is also common for VFDs to provide debugging information such as fault codes and

3149-492: The motor to a high starting torque and to current surges that are up to eight times the full-load current. AC drives instead gradually ramp the motor up to operating speed to lessen mechanical and electrical stress, reducing maintenance and repair costs, and extending the life of the motor and the driven equipment. Variable-speed drives can also run a motor in specialized patterns to further minimize mechanical and electrical stress. For example, an S-curve pattern can be applied to

3216-481: The motor to be protected for a hazardous area. The following table compares AC and DC drives according to certain key parameters: ^ High-frequency injection AC drives can be classified according to the following generic topologies: Most drives use one or more of the following control platforms: Variable-frequency drives are also categorized by the following load torque and power characteristics: VFDs are available with voltage and current ratings covering

3283-433: The motor voltage magnitude, angle from reference, and frequency so as to precisely control the motor's magnetic flux and mechanical torque. Although space vector pulse-width modulation (SVPWM) is becoming increasingly popular, sinusoidal PWM (SPWM) is the most straightforward method used to vary drives' motor voltage (or current) and frequency. With SPWM control (see Fig. 1), quasi-sinusoidal, variable-pulse-width output

3350-434: The necessary action promptly to rectify the fault" and gave the consortium the "highest quality score" as the basis for awarded them subsequent train contracts ( C151C and T251 ) in 2015 despite the defects were discovered since. The contract for C151B trains had been awarded to the same consortium in 2012, prior to the knowledge about the faults being known. On 9 July 2016, a Singapore-based alternative media republished

3417-416: The need for an overhead line or third rail . An example is Alstom ’s hydrogen -powered Coradia iLint . The term hydrail has been coined for hydrogen-powered rail vehicles. Many battery electric multiple units are in operation around the world, with the take up being strong. Many are bi-modal taking energy from onboard battery banks and line pickups such as overhead wires or third rail. In most cases

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3484-453: The operation of the drive. An operator interface keypad and display unit is often provided on the front of the VFD controller as shown in the photograph above. The keypad display can often be cable-connected and mounted a short distance from the VFD controller. Most are also provided with input and output (I/O) terminals for connecting push buttons, switches, and other operator interface devices or control signals. A serial communications port

3551-472: The order of 22 trainsets under Batch 1. Sifang handled the manufacturing and testing of the rolling stock, while KHI oversaw the project and design. The C151A contract was the first successful joint venture between these two companies in the international market. With the delivery of C151A trainsets, trains were actually operated on the East–West Line until October 2013. C151As were temporarily suspended from

3618-553: The outer end of the pair, saving space and expense over a cab at both ends of each car. Disadvantages include a loss of operational flexibility, as trains must be multiples of two cars, and a failure on a single car could force removing both it and its partner from service. Some of the more famous electric multiple units in the world are high-speed trains: the Italian Pendolino and Frecciarossa 1000 , Shinkansen in Japan,

3685-508: The rectified trains returned to Singapore . Opinions from Railway Experts and Analysts: This incident was a source of public concern among Hong Kongers because subway operator MTR had ordered fleets of a new train from the same manufacturer CSR Sifang. The news was quickly reported in other Hong Kong media. The incident also created a public uproar in Singapore, generating a public reaction. Some of these discussions included criticism of

3752-471: The same opinion that the defects are "not safety-critical". During the same period, a rumour posted on 4 February 2015 alleging misconduct of CSR Sifang faking technical data involving almost 70 people from multiple departments since November 2010 for failing to meet the standards set by Kawasaki Heavy Industries gained traction amongst the public. The consortium refuted the rumor on 7 July 2016 and threatened to take legal actions. The LTA also publicly dismissed

3819-402: The same polarity. In starting a motor, a VFD initially applies a low frequency and voltage, thus avoiding high inrush-current associated with direct-on-line starting . After the start of the VFD, the applied frequency and voltage are increased at a controlled rate or ramped up to accelerate the load. This starting method typically allows a motor to develop 150% of its rated torque while the VFD

3886-667: The shades red , blue and green seats. Priority seats in darker shades. The floor of the train has also been grey floor and cream interior walls similar to that of C751B trains. The coupling configuration of a C151A in revenue service is DT–M1–M2+M2–M1–DT. The car numbers of the trains range from x501 to x570, where x depends on the carriage type. Individual cars are assigned a 4 digit serial number. A complete six-car trainset consists of an identical twin set of one driving trailer (DT) and two motor (M) cars permanently coupled together. For example, set 535/536 consists of carriages 3535, 1535, 2535, 2536, 1536 and 3536. On 5 July 2016,

3953-435: The speed and torque is same (positive or negative) polarity in both directions. Certain high-performance applications involve four-quadrant loads (Quadrants I to IV) where the speed and torque can be in any direction such as in hoists, elevators, and hilly conveyors. Regeneration can occur only in the drive's DC link bus when inverter voltage is smaller in magnitude than the motor back- EMF and inverter voltage and back-EMF are

4020-404: The states of the input signals. Most VFDs allow auto-starting to be enabled. Which will drive the output to a designated frequency after a power cycle, or after a fault has been cleared, or after the emergency stop signal has been restored (generally emergency stops are active low logic). One popular way to control a VFD is to enable auto-start and place L1, L2, and L3 into a contactor. Powering on

4087-568: The traction current to motors on both cars. The multiple unit traction control system was developed by Frank Sprague and first applied and tested on the South Side Elevated Railroad (now part of the Chicago 'L' ) in 1897. In 1895, derived from his company's invention and production of direct current elevator control systems, Frank Sprague invented a multiple unit controller for electric train operation. This accelerated

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4154-501: The trains were returned for rectification works, and have since published official statements to address FactWire's specific allegations. On 6 May 2009, the Land Transport Authority announced that KHI and Sifang had won over Hyundai Rotem , Bombardier Transportation and Mitsubishi Heavy Industries to secure the contract at a cost of S$ 369 million, despite Hyundai Rotem offering the lowest bid at S$ 323 million for

4221-426: The two cars in the set. Since neither car can operate without its "partner", such sets are permanently coupled and can only be split at maintenance facilities. Advantages of married pair units include weight and cost savings over single-unit cars (due to halving the ancillary equipment required per set) while allowing all cars to be powered, unlike a motor-trailer combination. Each car has only one control cab, located at

4288-691: The voltage magnitude of the inverter's output to the motor be adjusted to match the required load torque in a linear V/Hz relationship. For example, for 460 V, 60 Hz motors, this linear V/Hz relationship is 460/60 = 7.67 V/Hz. While suitable in wide-ranging applications, V/Hz control is sub-optimal in high-performance applications involving low speed or demanding, dynamic speed regulation, positioning, and reversing load requirements. Some V/Hz control drives can also operate in quadratic V/Hz mode or can even be programmed to suit special multi-point V/Hz paths. The two other drive control platforms, vector control and direct torque control (DTC), adjust

4355-421: The voltage/current-combination ratings used in different drive controllers' switching devices such that any given voltage rating is greater than or equal to one to the following standard nominal motor voltage ratings: generally either 2 + 3 ⁄ 4 .16 kV (60 Hz) or 3 + 3 ⁄ 6 .6 kV (50 Hz), with one thyristor manufacturer rated for up to 12 kV switching. In some applications

4422-464: Was awarded to KHI and Sifang by the Land Transport Authority . In 2013, a further order of 13 trainsets was placed, with all 35 trainsets in revenue service as of 2014. In 2016, an investigative news report from Hong Kong's FactWire alleged that C151A trainsets were discreetly being shipped back to Qingdao for rectification due to multiple defects, including an exploding battery and cracks on trains. The Singapore government subsequently acknowledged

4489-663: Was closed in January 2009. The tender results were published in May 2009. The C151A trains are the third commuter type Electric Multiple Unit (EMU) made in Japan to feature electric systems fully manufactured by Fuji Electric . Propulsion is controlled by VVVF Inverter with 2-level IGBT semiconductor controller, rated at 415 kV. Each inverter unit controls two motors on one bogie (1C2M), and one motor car features two of such units. Motors are three-phrase AC induction type, model MLR109, with

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