Abstract: With the improvement of port automation, AGV(Automated Guided Vehicle) has become the trend of container handling systems. This article mainly describes the successful application of the INVT GD800 four-quadrant inverter in some seaports of AGV.
Keywords: AGV, Four-quadrant, GD800
AGV is a kind of handling vehicle with safe protection and full loading and unloading ability, equipped with automatic guidance device such as electromagnetic or optical, it can travel along the specified guide path. Its movement route and action can be controlled by a computer in addition to the drive.
AGV has the characteristics of good flexibility, high degree of automation and high level of intelligence. The travel path of the AGV can be flexibly changed according to the warehousing space requirement, and the cost of the operation path change is very low, compared with the conventional transmission line.
In order to improve the transportation efficiency, AGV needs to adjust the speed. The frequency conversion speed regulation has the advantages of large speed range, good smoothness, high precision, and is widely used in the field of electric transmission.
AGV's performance requirements for frequency converters are as follows:
1. The inverter has enough starting torque to meet the requirements of AGV with heavy load start-up;
2. When the input voltage fluctuates and the load changes greatly, the inverter can maintain the bus voltage stability and ensure good output characteristics;
3. The inverter can meet the requirement of quickly parking within the specified safety distance when the AGV is full speed full load;
4. The frequency converter must ensure front and rear wheel speed synchronization and power balance;
5. The inverter can realize CANopen communication with the on-board PLC;
6. The inverter is small in size and easy to install in the limited space of the vehicle body.
3.Solution of AGV system
The basic principle of AGV is that the diesel generator supplies three-phase AC power to the PWM rectifier. The entire vehicle is driven by two inverters using droop control, one driving the front wheels and the other driving the rear wheels. The two inverters adopt master-slave control, the master adopts speed control, and the other slave is torque control. The power balance is achieved by setting a droop frequency.
Motor rated voltage is 440V, the diesel generator output voltage is 380v, we adopt the GD800 PWM rectifier to increase the DC bus voltage, so that the output voltage reach 440V. In order to protect the generator, we adopt braking unit, to consume the regenerative energy.
The following is the system diagram:
4.Advantages of GD800 inverter
GD800 is a frequency converter developed specifically for engineering applications. Be suitable for heavy-duty applications with high overload capacity, high reliability and continuous operation, especially in metallurgy, ports, lifting, testing, machine tools, petroleum, petrochemical, chemical, power, construction, mining, vehicle transportation, papermaking, variable frequency power supply and other industries.
Main technical characteristics:
Excellent handling performance
● Closed loop vector, variable frequency separation, torque control mode to meet customer requirements;
● External power supply for control and power supply equipment to facilitate system connection and debugging;
● STO, SS1, SLS, BC protection;
● PWM rectifier unit, inverter unit and LCL PWM filter device to meet the needs of integrated solutions;
● Standard four-quadrant drive cabinet products;
● High reliability
● Optical fiber communication between system units to achieve optical isolation;
● Standard cabinet products meet the requirements of C3.
The GD800 series products support a variety of communication modes to enable flexible application of the vfd drive in various control systems. The successful application at the port AGV proves that the GD800 four-quadrant frequency inverter has good performance, high reliability and stability. The series of frequency converters have broad application prospects in port storage, manufacturing and AGV equipment in other industries.
 《GD800 series operation manual from Shenzhen INVT electric company》
 《GD800 series hardware catalog from Shenzhen INVT electric company》