Mitsubishi VFD (Variable-frequency Drive) application effect on beer production line

one. Introduction to Mitsubishi VFD (Variable-frequency Drive) speed regulation method

Mitsubishi VFD (Variable-frequency Drive) external terminal speed regulation can be divided into analog speed regulation and multi-stage speed regulation. Analog speed regulation can use voltage DC0~10V or current DC4~20mA for stepless speed regulation. Our factory uses 0~10V analog voltage as the given value for open-loop speed regulation; multi-speed uses external input terminals SD, STF, RL, RM, and RH for three-speed speed regulation. RL, RM and RH are the three speed selection terminals of low, medium and high speed, SD is the input common terminal, and STF is the start forward signal. As shown in Figure 3, when Y10 and Y11 have outputs, the VFD (Variable-frequency Drive) runs at low speed; when Y10 and Y12 have outputs, it runs at medium speed; when Y10 and Y13 have outputs, it runs at high speed. The principle of VFD (Variable-frequency Drive) 2 and 3 is the same. The three speeds are set to 15Hz, 30Hz and 45Hz respectively. When adjusting the analog speed, adjust the partial pressure ratio of W1 and W2 to set the VFD (Variable-frequency Drive) to run at high speed when KA1 is closed, and at low speed when KA2 is closed. When KA1 and KA2 are both disconnected, the VFD (Variable-frequency Drive) will Frequency Drive) is the highest speed; VFD (Variable-frequency Drive) 2 and 3 have the same principle. Through programming, the PLC selects the control mode according to the signal sent by the operating console: analog speed regulation or multi-speed speed regulation. The multi-stage speed regulation of Mitsubishi VFD (Variable-frequency Drive) has a higher priority than analog speed regulation (1).

two. System Components

According to the process requirements, the conveyor belt in front of the filling machine is divided into several sections. A, B, C, D and E are conveyor belts, and M13, M14 and M15 are the driving motors of A, B and C belts respectively. The D belt is mechanically linked to the filling machine, and the E belt is driven by another motor. In addition, there are photoelectric sensors on each belt to detect the bottle flow speed. The PLC adjusts the speed of each section of the conveyor belt according to the bottle flow.

VFD (Variable-frequency Drive) 1, 2, and 3 control motors M13, M14, and M15 respectively. The main circuit wiring diagram is omitted. The PLC is FX2-64MR. FMA﹑11 is the output signal from the filling machine VFD (Variable-frequency Drive) 0~10V, which is converted by the signal isolator into the control signal of VFD (Variable-frequency Drive) 1, 2, 3. KA1-6 in the picture is the auxiliary relay. W1-6 is a voltage divider potentiometer. The input terminals of the PLC are omitted. FMA﹑11 is the output signal from the filling machine host VFD (Variable-frequency Drive). The PLC in the two pictures is the same PLC. COM6 in Figure 2 is connected to DC24V voltage to control the auxiliary relay.

three. control thoughts

There are two speed adjustment methods for VFD (Variable-frequency Drive) 1, 2, and 3: 1. The analog signal DC0~10V from the filling machine host VFD (Variable-frequency Drive) is converted into linear DC0~10V through the isolator. , and then divided by the potentiometer as the given signal of VFD (Variable-frequency Drive) 1, 2, 3 to control the motor M13, M14, M15, so that the speed of the conveyor belt and the filling machine can be well matched; 2. Use multi-stage speed control terminals SD, STF, RL, RM, RH, and program through PLC, and the PLC sends control signals to control the speed. The PLC determines which speed control method to use based on the signal from the filling machine console, and selects high and low speeds based on the bottle flow situation. In analog signal control, the VFD (Variable-frequency Drive) output speed is controlled through the combination of auxiliary relays KA1 and KA2, KA3 and KA4, KA5 and KA6, and the voltage division of W1, W2, W3, W4, W5 and W6. At multi-stage speeds, the output frequency of each VFD (Variable-frequency Drive) is adjusted separately through the PLC output Y10, Y11, Y12, Y13, Y20, Y21, Y22, Y23, Y24, Y25, Y26, Y27 to achieve the multi-stage conveyor belt speed. Speed matching and speed matching with the filling machine. In the adjustment of the analog control method, the adjustment of the potentiometer voltage dividing ratio is the key. Through exploration during production debugging, a better speed match was finally found. Once the partial pressure ratio is adjusted, it cannot be changed at will.

Four. Application effect

In the two speed control modes, the multi-stage speed frequency of each VFD (Variable-frequency Drive) and the voltage dividing ratio of the potentiometer are adjusted separately to achieve a good match between the speed of the conveyor belt and the speed of the filling machine, and the operation is stable and reliable. Practice has proved that FR-A540E VFD (Variable-frequency Drive) can fully meet the output requirements of beer filling production lines.