Long-Ma, the dragon-scaled winged horse of Chinese mythology, had to come to life during the official ceremony in the Beijing Olympic Stadium in October 2014. France and China planned to celebrate the 50th anniversary of their diplomatic relations. With only 12 months lead time DINTEC, a well-known system integrator for electric drives and hybrid applications, accepted the challenge to power the dragon-horse.
In October 2013 Compagnie La Machine (www.lamachine.fr) approached their partner DINTEC with the request to power a giant dragon-horse. It should allegorize Long-Ma, a fabled winged horse with dragon scales in Chinese mythology. Very quickly it became obvious that this project would be like no other. As Long-Ma should come to life within 12 months only and then be the main attraction at the celebrations for the 50th anniversary of the diplomatic relations between China and France, the pressure on DINTEC was extreme. But being an experienced system integrator especially for off-highway applications DINTEC took on the challenge and got the responsibility for the whole power system. The passion for mobile machines and for the entertainment created by the amazing creatures of Compagnie La Machine allowed DINTEC to master the system from power generation, storage and distribution to control and sensors. DINTEC dedicated a multidisciplinary team of 5 engineers who started by understanding the energy balance of the animal and the constraints in terms of operating mode (hybrid, fully electric for 45 minutes). After 1,800 hours of engineering work a complete hybrid architecture was defined [see pic. 1] in detail and the software for the power management written and compiled. So only 7 months after the kick-off a prototype of the system could already be seen working in DINTEC’s workshop.
Hybrid PowerPack
In order to supply the 620 VDC electric net DINTEC designed a bespoke PowerPack driven by a Perkins 6-cylinders Tier 4 Interim engine to lower emissions. The diesel engine is coupled to the STW powerMELA 140 kW E-machine. Due to its integrated inverter the powerMELA permits four quadrant operation and works here as a generator. Running at variable speed depending on real-time power demand, the combination offers best-in-class fuel consumption. Lots of efforts have also been made in terms of PowerPack enclosure as the giant Long-Ma had to remain a silent machine (see pic. 2). Even when the diesel engine starts advanced noise insulation keeps Long-Ma quiet.
Electric Generator and Motors
The main electric consumers are two STW powerMELA 140kW E-machines working as motors. They supply hydraulic power for all the movements (head, body, legs, eyes…), the hydrostatic transmission and the steering system. A brake chopper has been implemented on the DC bus to avoid over-voltage in case of hard braking. The brake chopper is also equipped with an electric insulation measurement system that permanently controls the electric isolation of the DC bus from the machine chassis. A shortcut here would be hazardous to the operators of Long-Ma. All electric components (batteries, motors, generator, inverters…) are connected to the DC bus through small cabinets integrated into the machine.
The giant also requests a number of additional electric networks so DINTEC supplied appropriate solutions derived from the 620Vdc bus. Inverters and filters take care of the transformation to the AC world with a 400Vac-50Hz (triphases + neutral) net for air compressors and water pumps and a 230Vac-50Hz net to power small AC motors, lights, music systems. A DC/DC converter converts the voltage down to 30Vdc to supply fans, controllers, and lights.
Energy Storage
After a deep benchmarking of technologies taking the duty cycle of the machine, its required lifetime and the constraints in terms of use and availability into account, DINTEC selected Sodium Nickel batteries for their high power and energy density and supplied 5 sets of 23.56 kWh each fitting to the 620Vdc net and weighing a total of 1,000 kg. While each set features its own cooling system, the batteries are designed to be charged from the grid but can also be directly charged from the embedded PowerPack when necessary.
Electronics
Animating such an animal smoothly and realistically means over 50 speed and position regulations for the movements of the head, the body, the legs and the displacement (hydraulic propelling and steering). To handle these numerous functions and also the communication between the 24 HMI (display, joysticks, keypads) and more than 200 sensors (angles, length for cylinder heads, pressures, temperatures, etc.), DINTEC defined a complex network of 16 embedded controllers communicating through 17 different CAN-buses.
The STW ESX-3XL was selected as the central control unit and brain of the system. The ESX-3XL can handle up to 124 I/Os and offers plenty of computing power and memory to run the sophisticated application. The steering and propelling get managed through the off-the-shelf STW ESX-C which is fully capable of controlling the rolling chassis. DINTEC used the ESX-C to implement the power management algorithms. These are capable of adjusting permanently the power generation to the machine requirements and make sure all requested movements can be operated at the right speed. Two ESX-IOX and eleven ESX-IOXp decentral I/O control systems for the hydraulic movement control of the head, legs, and eyes were deployed by DINTEC. Also, efficient communication between all CAN participants was established. At last, a STW ESX-C2C with mobile communication capabilities was added so that diagnosis, software updates and machine follow-up was possible remotely using DINTEC’s well-proven Web Server.
The Result
After intensive testing in Nantes, France, Long-Ma passed all controls and certifications handled by TUV Belgium which is specialized in unusual and therefore special applications. Long-Ma then left Nantes in September 2014 aboard an Antonov 124 to land the next day in Beijing, China. After being re-assembled and after several days of testing and rehearsals for the ceremony, Long-Ma performed 3 days of intensive shows, leaving unforgettable memories to the Chinese public. Finally, Long-Ma returned back to Nantes in June 2015 for a couple of presentations and performances. After those Long-Ma is due to be permanently located in China as part of a larger project.
Both companies, DINTEC as the system integrator and STW as the provider of the control system, the power generation and motors were proud to work on a project of this scale. This pride reached its peak when after 12 months the engineered system gave life to the animal which took part in the big show for the celebrations of the 50th anniversary of China’s and France’s diplomatic relations. This project could be realized on time only due to the long term relationship between DINTEC and STW. Only this way the requirements of the machine manufacturer could be met as all technical challenges could be solved by seamless communication. DINTEC’s deep know-how in electrification and electrohydraulic systems combined with the quality of the STW components once again achieved customer satisfaction.
About DINTEC:
DINTEC is a well-known System Integrator for Electric Drives and Hybrid Applications across Europe, the company is able to manage highly innovative technologies for off-highway applications. Based in Nantes – France, DINTEC collaborates with OEMs in segments such as Agriculture, Construction, Mining, Material Handling or Ground Support Equipment.
About STW:
STW is an internationally active company that has supported the world's leading manufacturers of mobile machines and industrial vehicles in the application of new technologies in automation, connectivity and e-mobility for over 30 years.
STW develops, manufactures and distributes a wide range of products for measurement and control, telematics and the electrification of the powertrain and implements.
Legal notice:
Long Ma Jing Shen, Original creation of François Delaroziere & Cie La Machine as part of France China 50 and supported by Institut Français.