外文翻譯---基于高壓無刷直流電機小型電動車的控制和結構（英文）

1、Instrumentation and Control of a High Power BLDC Motor for Small Vehicle Applications Alexander Rowe1, Gourab Sen Gupta1, Serge Demidenko2 1School of Engineering and Advanced Technology, Massey University, Palmerston No

2、rth, New Zealand School of Electronics and Computer Engineering, RMIT International University Vietnam ARowe@bto-ltd.co.nz, g.sengupta@massey.ac.nz, serge.demidenko@rmit.edu.vn Abstract—Brushless DC (BLDC) motors are b

3、ecoming an increasingly popular motor of choice for low powered vehicles such as mopeds, power assisted bicycles, mobility scooters, and in this reported application, motorised mountain boards. With rapid development

4、s in technology, high energy density batteries such as Lithium-ion Polymer batteries are becoming more affordable and highly suitable for such vehicles due to the superior charge rate and light weight of the lithium c

5、hemistry batteries. This combined with the high power, light weight, and low cost BLDC motor results in the BLDC motor being a very favourable solution over an internal combustion engine for low power vehicles with p

6、ower requirements of up to 7kW. A BLDC motor controller was developed specifically for the motorised mountain board application. The motor controller is a sensored BLDC motor controller which takes inputs from Hall Ef

7、fect sensors to determine the rotor position. Many other sensors are used to monitor the variables that are critical to the operation of the motor controller such as the motor phase current, battery voltage, motor te

8、mperature, and transistor temperature. The reported system is further enhanced by several additional features such as output for an LCD screen, regenerative braking, timing advance, cruise control, and soft start func

9、tions. These topics are discussed briefly in this paper. Keywords- sensored BLDC motor controller, regenerative braking, timing advance, electric skateboard, Hall sensors I. INTRODUCTION A motorised mountain board allo

10、ws users to take the extreme sport of mountain boarding, which is normally limited to downhill use only, to flat and uphill surfaces. This gives the users a much wider choice of locations where they can use the mount

11、ain board. A BLDC outrunner motor has been used for this application. An outrunner motor was chosen for its low speed (130 RPM/v), high torque characteristics which reduces the gearing requirements; a 3.8:1 gear ratio

12、 is used which is achieved in a direct chain drive. The motor is a Turnigy C80100-130 which has a power rating of 6.5 kW. This amount of power is sufficient to drive small vehicles to speeds of approximately 70 km/hr

13、; however the gearing and battery voltage has been selected to limit the mountain board to 50 km/hr. Consequently, the torque at the wheels is increased and is sufficient to allow the motorised mountain board to climb

14、 steep hills. A sensorless controller requires the motor to produce a measureable back EMF for the motor controller to be able to determine the position of the rotor and therefore cannot provide smooth commutation at

15、 start up and low speeds. In contrast, a sensored BLDC motor controller uses position sensors and therefore is able to determine the rotor position at any speed. This allows for smooth commutation during start up. A

16、sensored BLDC motor controller was built for this reason. II. ELECTRICAL SYSTEM OVERVIEW A mixed-signal field programmable microcontroller, the Silicon Laboratories C8051F020, has been used to control the motor driver

17、 circuit according to a range of inputs from various sensors. Custom made software was programmed in C which runs on the microcontroller. This software determines the operation of the motor controller. Fig. 1 shows th

18、e functional blocks of the motor controller. The motor controller uses a three phase H-bridge to drive the motor. This circuit was chosen because it allows for four quadrant operation of the motor, as well as coasting

19、. Fig. 2 shows the schematic diagram of the three phase H-bridge. Figure 1 Overview of the major components of the motor controller978-1-4577-1772-7/12/$26.00 ©2012 IEEEB. Regenerative braking The motor controller

20、 incorporates a simple regenerative breaking function. The amount of energy regenerated during normal use in a flat or uphill application is very little. However, because regenerative braking is the only braking metho

21、d that does not simply convert kinetic energy into heat energy, which heats up the transistor heat sink and the motor, it was included in the project. Regenerative braking is achieved by boosting the back EMF of the

22、 motor to a higher voltage than the battery voltage by using a boost converter circuit. Fig. 4 shows the schematic diagram of a basic boost converter circuit [5] This circuit is implemented without any additional hard

23、ware. It is created by using the low side transistors of the three phase H-bridge as the switching device, the motor windings as the inductor, and the high side flyback diodes as the diode in the boost converter circu

24、it. Three of these circuits are in fact used, one for each of the three phases. The output voltage of the boost converter is controlled by varying the PWM duty cycle of the low side transistor. As the output voltage i

25、s increased, the charging current is increased which results in the braking force being increased. Therefore the braking force is controlled by reading the position of the brake lever and adjusting the duty cycle acco

26、rdingly. The charging current has to be kept within specified limits to prevent damage to the battery pack. For the Lithium-ion Polymer battery pack used in this application, the maximum charging current is 20A. It w

27、as calculated that 20A of charge current provides sufficient brake power to slow down from 30 km/hr to a complete stop in 3s C. Timing Advance Timing advance is used in both brushed and brushless DC motors [6]. In bru

28、shed DC motors this is done by mechanically moving the position of the brushes relative to the motor windings. In BLDC motors, timing advance is done electronically by commutating the motor sooner than it would norma

29、lly do so. Ideally, the amount of timing advance (expressed as an angle of electrical rotation) would be continuously variable from 0° at zero speed to some maximum advance angle at the maximum motor speed. This

30、can be done with a microcontroller, however it requires much processing and would require a dedicated microcontroller [7]. The large amount of processing is required because the microcontroller must predict when the n

31、ext motor position will occur based on the speed of the motor, and then calculate the time delay between the last motor position transition and the next transition for the desired angle of advance. With this informat

32、ion the microcontroller can trigger the commutation at the calculated time after the previous transition. D. Internal position sensors In this application, a simple approach to timing advance has been taken; two sets

33、of Hall Effect sensors have been installed inside the motor. One set is positioned for neutral timing, the other set is positioned 30° (electrical rotation) from the neutral timing set. This second set of Hall Ef

34、fect sensors produce a signal for 30° advanced timing in the forward direction or 30° retarded timing in the reverse direction. This angle of advance was recommended by [8] as an optimum amount of timing ad

35、vance for this motor at 5000RPM which is near the top speed of the motor when running on a 42V battery. Also, because the motor has a 12 pole stator, each pole is spaced 30° apart. This means that both the neutra

36、l timing and advanced timing set of Hall Effect sensors can conveniently be mounted in the gaps between the stator poles. Fig. 5 shows waveforms of the signals from the neutral and 30° advanced motor position sen

37、sors. The top three waveforms are from the neutral timing set and the bottom three are from the advanced timing set of motor position sensors. This shows the advanced timing transitions occurring 30° of electric

38、al rotation before the neutral timing transitions. With this angle of timing advance, it also works out that the signal for 30° advanced timing in the reverse direction can be generated from the signal from the s

39、econd set of hall sensors. This is because the signal for 30° retarded timing is identical to the 30° advanced signal when phase shifted by 60° (which is the spacing between motor position transitions).

40、 This results in the 30° retarded signal being exactly one sequence behind the 30° advanced signal. By generating this third signal, it is possible for the Motorboard to use 30° advanced timing in the F