PESHAWAR: The Bus Rapid Transit service resumed here on Saturday after remaining suspended for around 40 days due to fire incidents in some buses.

The development came after the Chinese bus manufacturer rectified the cause of fire.

A statement issued by the TransPeshawar, the government-owned company set up to manage bus operations, said the service was launched on Saturday morning and would continue from 6am to 10pm.

It said it had also launched express bus service, which would begin from Chamkani and make stops at Sardar Ghari, Lahori Adda, Hashtnagri, Malik Saad, Khyber Bazaar, Dabgari Garden, Saddar Bazaar, Peshawar University, Mall of Hayatabad and Karkhano Market.

Also, there will be a special route from Khyber Bazaar to Mall of Hayatabad. Three Hayatabad feeder routes will become operational today (Sunday).

Chinese company rectifies cause of recent fire in buses

The BRT bus service was launched on Aug 13 by Prime Minister Imran Khan. However, it was suspended on Sept 16 in the wake of four fire incidents in buses.

A team of engineers from the Chinese bus manufacturer reached Peshawar to identify and rectify the issues causing fire.

The company submitted a report to the TransPeshawar attributed fire incidents to the malfunctioning of a motor controller installed between hybrid batteries and electrical motor.

It said the motor control unit of buses ‘acted as the core of the hybrid systems, and converted direct current from battery to the alternating current to drive the motor by the complicated control of variable parameters to control the parameters to control the power performance of electric motor and bus’.

The company said the MUC was managed by a programme, which was developed according to the input of external conditions.

It said as buses started, that system worked in such a manner that batteries gave energy via motor controller to motors to drive the buses initially from idle position or re-circle the energy by converting the kinetic energy to current and charging back to the batteries in deceleration.

“During this path, the DC-AC converting of current flows generates the ripple current in the MCU and in the circuit. Under the normal conditions, the ripple current would be absorbed by the batteries or they are smoothed via capacitors in motor controller.”

The company said due to the unexpected abnormal external conditions, which included multiple parameters, increased the ripple current up to the maximum 750A stopping the MCU capacitors from smoothing the ripple current as it was beyond their capacity.

“The failure of capacitors directly led to the violent heat up and malfunction and even explosion, which consequently led to short circuit of high volt power circuit and thus leading to the eruption of fire on the vehicles.”

In the report, the company noted that the peak current was supposed to be restrained by software upgrade to limit the flow of the current from the motor controller change.

It, however, pointed out that certain electronic components in the MCU of buses were checked to have been damaged by the abnormal current before the software updating that caused the fire incidents.

The company said it had developed a solution for the problem, including redesign and replacement of bus motor controllers.

It also said it would replace motor controllers in 18 meters model buses for better temperature resistance performance.

The company’s solution also included the changing of the insulated gate bipolar transistor in the motor controller, which will reserve the larger power capacity and improve the performance of the temperature resistance and current converting efficiency.

In addition, the temperature sensors will be installed in motor controller to record and provide warning for any abnormal temperature in the unit.

The company said the single motor controller in 12 meters long buses would be changed to the dual one.

It also assured the authorities that it stood by its commitments mentioned in the contract and would continue offering full support and cooperation for the smooth running of the bus service.

Published in Dawn, October 25th, 2020