2.11. Selection of motor parameters and counterweights
2.2, electric drive system solution
Traction machine drive system requirements:
1. Drive the permanent magnet synchronous motor to realize closed loop vector control.
2. The encoder of the West German elevator permanent magnet synchronous motor is HEIDENHAIN ERN 1387, incremental encoder SIN/COS (1 Vpp).
3. The inverter is required to have Encoder Simulation TTL differential 5V output signal. This signal is output to the elevator control board to monitor the actual speed of the elevator.
4. In order to ensure the comfort of the elevator, the speed loop proportional integral is switched according to the actual speed.
5, the inverter pulse width modulation frequency needs 8KHz, to achieve the purpose of reducing motor running noise.
3. Selection of electric drive system
Because in the elevator hoist system, the permanent magnet gearless synchronous traction machine for the elevator directly provides the load weight and the running line speed according to the experience of the elevator industry. Regarding the inverter, it is necessary to select the heavy-duty power corresponding to the synchronous motor power, and the customer provides the inverter power and the braking resistor power through calculation. However, in order to reduce the noise of the motor running, the pulse width modulation frequency of the inverter needs to be increased to 8KHz, so it is necessary to consider the output current derating caused by the actual inverter frequency increase due to the pulse width modulation frequency. When the pulse width modulation frequency of the inverter needs to be increased to 8KHz, the inverter allows the continuous output current to be derated to 70% of the rated value.
Elevator running comfort settings:
In order to meet the passenger's requirements for comfort in the elevator, it is necessary to extend the ramp function generator and the speed controller.
The extended ramp function generator provides the initial arc and the end arc during the motor start acceleration process, achieving a smooth transition of the speed, realizing the variable acceleration function during the entire acceleration and deceleration of the elevator, and the elevator starts and accelerates quickly. When the given speed is reached, the acceleration of the elevator operation is reduced, the comfort of the elevator ride is improved, and the impact of the elevator from the sudden start of the stationary state and the acceleration of the elevator to the set speed is avoided.
