Application of KE300A Frequency Converter in Industrial Washing Machine

2022-04-01

1. The composition and working principle of a fully automatic industrial washing machine

Fully automatic industrial washing machine refers to a large-capacity washing machine that has functions such as initial washing, washing, rinsing, bleaching and dehydration, and can realize automatic conversion without manual operation between functions. The washing machine can be divided into three types: suspension vibration isolation type, water injection balance vibration isolation type, and gravity fixed type according to different methods of vibration reduction and vibration isolation. At present, the mainstream products on the market are suspension vibration isolation automatic industrial washing machines. It is mainly composed of shell, frame panel, inner roller of main shaft, transmission system, anti-vibration system, front door parts, feeding parts, braking parts, water discharge valve parts, super-vibration parts, control parts, pipeline parts and pneumatic system.

The working principle of the fully automatic industrial washing machine is that, under the unified scheduling management of the timing controller, the asynchronous motor is controlled by the frequency converter to continuously perform forward and reverse rotation to realize the asynchronous movement of the water and the clothes, so that the water and the clothes rub against each other so as to achieve the purpose of cleaning. It mainly has the following washing procedures:

Start→

wash→

even cloth→

middle dewatering→

deep dewatering→

end

2. Transmission system of automatic industrial washing machine

The transmission system is an extremely important part of the industrial washing machine, and it participates in the whole washing process because it mainly provides power support for the washing machine.

The transmission system is composed of an electric motor and various speed change mechanisms. Now the frequency converter is mainly used, so its components are significantly simplified. Generally, it is composed of a frequency converter, a frequency conversion motor, a pulley and a transmission belt. And in the whole washing stage, with the automatic adjustment of the frequency of the frequency converter, the constant torque speed change (stepless speed regulation) of the device without impact and intermediate transition (gearbox, speed change device or coupling, clutch, etc.) is realized, so that the the energy consumption of the washing process is significantly reduced.

With its unparalleled performance and absolutely excellent price-performance advantage, the frequency converter solves the technical difficulties of industrial washing machines such as high starting torque, multi-speed, wide voltage range, automatic slip compensation and fast and powerful communication methods. And it has stable performance, can adapt to a variety of complex high temperature, high humidity environments. The scientific custom V/F curve is adopted to make the washing machine start smoothly, the current is reduced, and the operation is stable during the customer's use, which is favored by customers.

Among them, kE300 series frequency converters are very suitable for industrial washing machines of various power levels, with beautiful appearance and outstanding quality, which can widely meet the needs of various customers.

3. Electric wiring diagram of transmission system and parameter setting of frequency converter

The power supply of the industrial washing machine is mainly three-phase 380AC. The wiring of the electric and its control system is as follows:

三相断路器：Three-phase circuit-breaker

电动机：Motor

工业洗衣机时序控制器及电气控制系统：Timing controller and electrical control system for industrial washing machine

外接制动电阻：External brake resistance

外接报警输出：External alarm output

In the above picture, D1/C0M and D2/C0M are start and stop as well as forward and reverse switching terminals of the frequency converter respectively. When only D1 and C0M are closed, the frequency converter will run forward; when only D2 and C0M are closed, the frequency converter will reverse. If D1 and D2 are disconnected from C0M at the same time or D2 and C0M are closed, the frequency converter is in stop state.

Terminals D1~D6 are digital signal ports, and their common terminals are unified as C0M, that is, it is effective to close and conduct with C0M. The D3, D4, and D5 terminals are the three multi-speed terminals set by the frequency converter by default, which can respectively correspond to the three washing programs of the industrial washing machine: even cloth, middle dewatering, and deep dewatering. The D6 and HD1 terminals are defined as acceleration and deceleration time selection terminals, so that users can conveniently select 4 different acceleration and deceleration times defined by the frequency converter, so as to scientifically and effectively determine the best acceleration and deceleration time for different washing programs of the industrial washing machine and achieve the best washing effect and significantly reduce the mechanical impact, so that the washing machine always works in the best state.

L1, L2, L3 are three-phase input, U, V, W are three-phase output of the frequency converter. T1A/T1B/T1C are frequency converter relay output terminals, among which T1B/T1C are normally closed ports, and T1A/T1C are normally open ports. According to the actual electrical design and control needs, customers can easily choose normally closed or normally open ports as alarm output. (+) and PB are the external braking resistor ports of the frequency converter, which are used to install braking resistors of various power levels that match the power level of the frequency converter. Note: the braking unit is built-in in machine of below 18.5KW.

The main function parameters of frequency converter for the automatic industrial washing machine are set as follows:

Function code	Setting value	Description of parameter setting
P0-02	1	The running command channel is controlled by external terminals
P0-03	6	Setting of multi-speed running
P0-08	9.0	Digital setting frequency is 9.0Hz
P0-10	130.0	The maximum set frequency of the frequency converter is 130Hz
P0-11	130.0	The upper limit of the maximum frequency of the frequency converter is 130Hz
P0-17	10	The duration of acceleration time 1 is 10S
P0-18	10	The duration of deceleration time 1 is 10S
P4-00	1	D1 terminal is set to run forward
P4-01	2	D1 erminal is set to run in reverse
P4-02	12	D3 terminal is set to multi-speed control 1
P4-03	13	D4 terminal is set to multi-speed control 2
P4-04	15	D5 terminal is set to multi-speed control 4
P4-05	16	D6 terminal is set as acceleration and deceleration time selection 1
P4-06	17	HDI terminal is set to acceleration and deceleration time selection 2
P4-11	1	Two-wire type 2
P5-02	2	Relay output selection (T1A, T1B, T1C) is set to frequency converter fault Set to frequency converter fault
P8-03	20	Acceleration time 2 is 20S
P8-04	20	Deceleration time 2 is 20S
P8-05	25	Acceleration time 3 is 25S
P8-06	25	Deceleration time 3 is 25S
P8-07	15	Acceleration time 4 is 15S
P8-08	15	Deceleration time 4 is 15S
PC-01	12	The effective corresponding frequency of D3 function terminal is 12Hz (even cloth)
PC-02	90	Effective corresponding frequency of D4 function terminal is 90Hz (middle dewatering) 130
PC-04	130	Effective corresponding frequency of D5 function terminal is 130Hz (deep dewatering)

Note:

1. The correspondence between multi-speed and washing programs and their frequency settings can be modified according to actual functional requirements.

2. The set 4 specific acceleration and deceleration times can also be modified according to the actual function matching requirements.

The function parameters of the dedicated custom V/F curve are as follows:

Function code	Setting value	Description of parameter setting
P3-00	1	V/F curve setting (multi-point V/F)
P3-01	2.0	Torque boost is 2.0%
P3-03	6	V/F frequency 1 is set to 6Hz
P3-04	25	V/F voltage 1 is set to 25% (380×0.25)
P3-05	25	V/F frequency 2 is set to 25Hz
P3-06	83	V/F voltage 2 is set to 83% (380×0.83)
P3-07	50	V/F frequency 3 is set to 50Hz
P3-08	100	V/F Voltage 3 is set to 100% (400V)

Matters needing attention: the customization of V/F curve is the most critical step in the application and debugging of frequency converters of industrial washing machine. During the debugging process, continuous optimization must be carried out according to the on-site working conditions, and the following principles must be mastered:

(1) The industrial washing machine should start slowly and smoothly, and the low-frequency starting torque of the frequency converter should be large.

(2) Pay attention to the slope of the V/F curve. If the slope of each setting point of the V/F curve is too large, the running current will be too large, and if the slope is too small, the operation cannot be started. Therefore, it should be comprehensively grasped according to the motor and its site conditions.

P.S: Because of the special technological requirements of the fully automatic industrial washing machine, when selecting the frequency converter, it is generally based on the rated power of the motor equipped with the washing machine, and the frequency converter with a higher power level should be equipped.