Permanent magnet synchronous motor and controller is installed on the electric dynamometer bench test, bench motor speed control, measured motor three-phase PWM duty ratio was 50%, all the negative current, the higher the speed, the greater the current, what a great god can explain the reason

CodePudding user response:

The negative current is bus current or a phase current? So-called current is negative, it is a reference to the volatility, volatility, may be your abnormal part of the interference and power supply, power supply work abnormal reason, generally cut right or not for you, the efficiency is low, lead to electrical power did not translate into mechanical power, cut correctly or not may be the cause of cutting phase voltage point is wrong, you also may be the result of your degaussing didn't have enough time to cut phase voltage point wrong,

CodePudding user response:

Three-phase PWM duty cycle is fixed value 50%, at this point I control algorithm is not running, motor torque output, in my understanding, the motor being dragged, there should be no current, but to me is a phase current, bus current is negative, the test when another set of motor controller, no current, that is why?

CodePudding user response:

Duty is higher than 50% remain unchanged, electricity at ordinary times all three phase line to the busbar is, relative to the three-phase motor is received on the same point, at this time can be as a three phase short circuit, when the motor is drag in power state, the three phase line will be a counter electromotive force is the voltage, the motor phase line is in short circuit condition, nature has the current phase line,

CodePudding user response:

Bridge arm under 50% of the time not half time is fully open, half open time is on the bridge arm, its valid values should not be zero?

CodePudding user response:

reference 1st floor dewei5_jiang response:

bus current or a phase current is negative current? So-called current is negative, it is a reference to the volatility, volatility, may be your abnormal part of the interference and power supply, power supply work abnormal reason, generally cut right or not for you, the efficiency is low, cause the electric power did not translate into mechanical power cut correctly or not may be the cause of cutting phase voltage point is wrong, you also may be the result of your degaussing didn't have enough time to cut phase voltage point wrong,

great god, is it possible that is the reason why we hardware design

CodePudding user response:

reference xu564543326 reply: 3/f

50% duty ratio remains unchanged, high levels of three phase line all got on the bus is, relative to the three-phase motor is received on the same point, as can be seen as three phase short circuit, when the motor is drag in power state, the three phase line voltage, there will be a counter electromotive force is motor phase line is in short circuit condition, nature has the current phase line,

50% of the time, I think it should be half the time on the bridge arms open, half the time under the bridge arm fully open, effective value should be zero, please great god points out that the wrong place

CodePudding user response:

The inertial drag is generator?
If I can observe whether there is a permanent magnet magnetic field transform?

CodePudding user response:

refer to 7th floor datao125 response:

inertial drag is the generator?
If I can observe whether there is a permanent magnet magnetic field transform?

is the generator and, yes, but you three-phase if not connected, it also only yes, produce the electric potential is not current PWM50 %, produced by the potential for power supply, the PWM cycle, half is positive, negative, half the effective value is 0, so it should not have a current

CodePudding user response:

refer to 7th floor datao125 response:

inertial drag is the generator?
If I can observe whether there is a permanent magnet magnetic field transform?

you refers to the permanent magnet magnetic field change is to point to?

CodePudding user response:

Accelerate the absorption current, motor slowdown would produce negative current

CodePudding user response:

references to the tenth floor worldy response:

motor accelerate absorption current, motor slowdown would produce negative current

it is the state driven, acceleration is also provided by the test bench,

CodePudding user response:

references to the tenth floor worldy response:

motor accelerate absorption current, motor slowdown would produce negative current

motor is driven by test bench, the acceleration is also provided by the platform, there should be no current, and what has happened is that there are current

CodePudding user response:

Motor by external mechanical drive, into the engine model, of course, to the output current