船用轴带发电机PTO-PTH模式介绍

KAD 30165.1/E

Edition 12/04 Notes for projection

Functional description and operating sequence for PTO/PTI-operation

of the generator including ponymotor

1. Functional description

1.1.Design

The PTO/PTI-generator (shaft machine) is designed as brushless synchronous machine which is to operate optionally either as generator or as motor. As special feature this machine is equipped on the N-side with an additional asynchronous motor of small output as pony motor. Shaft machine and asynchronous motor are one constructional unit with a common shaft. The excitation unit ist fitted on the machine and can be switched over for PTO- or PTI-operation, with uniform functioning.

The terminal assignment for switchboard devices is indicated in the wiring diagram. The switches and auxiliary contacts required for PTO- and PTI-operation are indicated in the principle sketch 30165.1.

The manufacturer supplies the shaft machine for PTO/PTI-operation ready for connection. The voltage regulator (AVR) for generator and motor operation, the sensors for thermal winding protection and anti-condensation heater are incorporated.

Apart from interlocks a change-over switch (S6) from PTO- to PTI-operation is to be installed in the switchboard. This is to prevent unintentional switching-on of the pony motor and an activation of the power-factor control at generator operation.

1.2.PTO-Operation

The shaft machine is working as generator and is driven by the main engine via clutch "B" and gearbox, thus providing shipboard power supply. The voltage regulator (AVR) is switched for parallel operation with static. The pony motor is switched off.

1.3. PTI-Operation

In case of need the shaft machine is to operate as motor supplied with power by the auxiliary generators and driving the ship's propeller via clutch and gearbox.

In order to avoid the high starting current as synchronous motor, the pony motor is switched on with clutch "B" disengaged. The pony motor then accelerates the shaft machine up to nearly rated speed, with the shaft machine acting like a generator and exciting itself up to rated voltage.

By this the machine is synchronized with the ship's network and then continues to run as self-excited synchronous motor.

At the sarne time the pony motor is switched off.

Attention! Final determination of power of pony motor can be result from specification of counter torque and moment of inertia of the clutch between gear and PTO/PTI – machine in disengaged condition first. The voltage regulator ist switched over and works as power-factor controller in the motor operating mode which controls the exciting current of the shaft machine in such a way that it works on the ship's network with a constant power factor