1. Strong acceleration ability
This advantage comes from the larger dynamic drag ratio. Under the condition of sufficient power and reasonable power output control, the greater the traction ratio, the greater the traction that the train can exert.
In China, the conventional traditional passenger train is generally a large marshalling bus with locomotive traction, with 88 tons of locomotive or 132 tons and 880 tons of passenger train marshalling-1 100 tons. The power is concentrated and the ratio of moving to towing is very small, which leads to the small traction that the train can exert. However, most of the EMUs are decentralized, and even if they are occasionally centralized, their moving-towing ratio is still greater than that of traditional large passenger trains. At the same time, this leads to two characteristics: EMU has stronger acceleration ability.
The acceleration ability is strong, and the train can return to normal running speed in a short time after leaving the station or passing through the speed-limited slow-moving section, which can bring a series of benefits.
For passengers, this means that the EMU with the same maximum speed limit can stop at more stations in the same long running time, which is convenient for travel, or in the case of mixed lines, the travel time is shorter than that of traditional large group buses.
For the dispatching department, this means that the extra time for the train to start and accelerate is less, which is easier to dispatch and easier to improve the railway operation efficiency.
For the manufacturer, this means that there is no need to squeeze the wooden bridge to increase the maximum allowable speed of the train in order to ensure the average speed of the train-which saves the cost of building cars and repairing roads at the same time.
Myth: "This advantage is absolute, regardless of the occasion".
The traditional trains of Bianxiao Group, the traditional trains with two locomotives and some traditional trains with two locomotives can also enter the field of weak power dispersion and have high acceleration ability on the flat ground. This is very common in foreign countries, but it is rare in China and has no universal significance. It is also reported that a commuter line uses DF 1 1G to tow three 22 buses a day, which is a strong power dispersion, but this situation is even more rare. So in China, this advantage has almost become the patent of EMU.
2. Strong climbing ability
This characteristic has been mentioned in the above characteristics, and it also comes from the large dynamic resistance ratio. Under the condition of sufficient power, the strong power dispersed train can still maintain the ability of quasi-high-speed or even high-speed operation on the 2% continuous ramp, while the weak power dispersed train can only go up in small steps, and the power concentrated train is even difficult to start, and it can only slowly rub forward when starting.
The short-listed high-speed trains in China are all high-power decentralized EMUs. The ramp's strong climbing ability and speed keeping ability provide great convenience for high-speed railway line selection, which can effectively reduce the cost of line construction and maintenance. Traditional trains and self-developed EMUs in China do not have the ability to pass at high speed or quasi-high speed on continuous steep slopes due to insufficient traction ratio or power, so this market is filled by technology and joint venture technology.
Myth: "This advantage is not absolute, regardless of the occasion".
The traction ratio of a single locomotive is generally 1:0, with super decentralized power and the strongest climbing ability. Many locomotives pull a small number of locomotives and have strong climbing ability. On a line with steep slope in Japan, even the EMU needs to be equipped with a patching machine. Only such a situation is not representative.
3. Commutation convenience
For the traditional trains in China, the reversing step in operation is "stop in the station-dismantle the front locomotive-reattach the locomotive at the rear of the train-restart". However, as long as the EMUs are in normal marshalling operation, both ends of the train must be controlled by the cab, and each cab can control the power and braking equipment on the whole train. When reversing, only the driver needs to go to the cab at the other end of the train. In this way, the step of locomotive shunting operation is omitted, thus saving the reversing time, reducing the time occupied by locomotive shunting on the station line, and reducing the probability of personal injury caused by car picking and trailer accidents.
Myth: "This advantage is absolute, regardless of occasion".
Traditional trains can also do this. Hang up the train at both ends of the train, or hang up the control car with cab at the other end, and then use reconnection cables to run through the whole train, so that the cab at both ends can control the braking capacity of the whole train and realize commutation without stopping. However, there is no such operation mode in China, so it is only the patent of EMU that it is not replaced when operating in China.
4. Luxury, comfort and high speed
This is the biggest misunderstanding.
The most widely used occasions of EMU are commuting in cities and suburbs. The core value of this train is to transport a large number of passengers with acceptable speed and comfort. Luxury and comfort come from high-consumption trains and are not necessarily related to EMUs. At present, some domestic media vigorously promote EMU, especially CRH series, which belongs to high-speed trains with high consumption, giving the public the illusion that EMU is luxurious, comfortable and high-speed.