Application of the hottest delta ve series frequen

Application of delta ve series inverter in crown block Abstract: This paper introduces the working principle and application environment of bridge crane, and expounds in detail the crown block function mode of delta vfd-ve series inverter. Provide guidance for the application of vfd-ve in crown block industry

keyword: bridge crane vfd-ve crown block function

abstract: the paper introduces the working principle of bridge crane and application environment And then expounds the platform of VFD - VE series inverter crane function as to provide guidance on VFD - VE application in industry.

keywords: bridge crane VF the price of lithium salt has soared in recent years. D-ve crane function

1 Introduction

bridge crane is a proposed method to expand 3D printing to carbon neutral materials. It has opened up a new direction in the field of sustainable development. It is also called overhead crane, which runs on overhead rail. The bridge of the bridge crane runs longitudinally along the track laid on the overhead on both sides, and the lifting trolley runs horizontally along the track laid on the bridge, forming a rectangular working range, which can make full use of the space under the bridge to lift materials without being hindered by ground equipment

bridge cranes are widely used in indoor and outdoor warehouses, workshops, wharves and open storage yards. Bridge cranes can be divided into ordinary bridge cranes, simple beam bridge cranes and metallurgical bridge cranes. This paper mainly uses delta ve series and B series inverters to drive the bridge crane separately without complications like other materials, and the crane operates smoothly

2 bridge crane

2.1 process structure

ordinary bridge crane is generally composed of lifting trolley, bridge running mechanism and bridge metal structure. The lifting trolley is also composed of lifting mechanism, trolley running mechanism and trolley frame

the lifting mechanism includes motor, brake, reducer, drum and pulley block. The motor drives the drum to rotate through the reducer, so that the steel wire rope can be wound on the drum or put down from the drum to lift and lower the weight. Trolley frame is a frame supporting and installing hoisting mechanism, trolley running mechanism and other components, usually of welded structure

the driving mode of crane operating mechanism can be divided into two categories: one is centralized driving, that is, a motor drives the long transmission shaft to drive the driving wheels on both sides; The other is driven separately, that is, the driving wheels on both sides are driven by a motor. Medium and small bridge cranes mostly adopt the "three in one" driving mode of combining brake, reducer and motor. In order to facilitate installation and adjustment, the driving device of ordinary bridge cranes with large lifting capacity often adopts universal coupling

ordinary bridge cranes are mainly driven by electricity, which are generally operated in the cab and also remotely controlled. The lifting capacity can reach 500 tons and the span can reach 60 meters

2.2 driving requirements

as a general equipment for handling large and heavy objects, the bridge crane has special requirements for the driving mechanism:

(1) the crane should have a large starting torque, usually more than 150% of the rated torque. If factors such as overload test are considered, at least 200% of the rated torque should be provided during the starting acceleration process

(2) due to the existence of mechanical brake, in order to smoothly switch the output torque of frequency converter and the braking torque of mechanical brake without hook slipping, the control sequence of frequency converter start signal and mechanical brake action signal must be

(3) when the lifting mechanism runs downward or the translation mechanism decelerates rapidly, the motor will be in the state of regenerative power generation, and its energy will be fed back to the power side. It is necessary to discuss how to deal with this part of regenerative energy according to different site conditions

(4) the load of the lifting mechanism changes violently at the moment when the lifted object leaves or contacts the ground, and the frequency converter should be able to smoothly control this impact load

3 variable frequency drive control

3.1 band brake drive control

for the special requirements of bridge cranes, Delta vfd-ve series inverter has designed customized special drive functions. Through the multi-function terminal of the frequency converter, the output current and output frequency are detected in real time to control the action of the crane brake system, as shown in Figure 1. When the output current and output frequency are greater than the set value at the same time during startup, open the packet gate; When the crown block stops, if any of the output frequency and output current is less than the set value, the package brake will be closed. This way can fully ensure that the frequency converter can provide enough torque and ensure the safety of the system

Figure 1 delta frequency converter band brake drive control

3.2 lifting drive control

the capacity of the frequency converter must be greater than the output required by the load, that is:

where - overload coefficient 1.33

- motor shaft output power required by the load, kw

- motor efficiency

- motor power factor

the starting torque required by the lifting mechanism is 1.3-1.6 times the rated torque, Considering the overload requirement of 125%, its maximum torque needs to be 1.6-2 times of the rated torque to ensure its safe use. For the frequency converter driving an equal power motor, it can provide an overload capacity of up to 60 seconds and 150% of the rated torque, so the overload coefficient k=2/1.5=1.33

after the capacity of the frequency converter is selected, current verification should also be done, that is:

where - current waveform correction coefficient (1.05-1.1 in PWM modulation mode)

- rated output current of the frequency converter, a

- rated current of the motor in power frequency power supply, a

general large tonnage cranes have two independently driven lifting mechanisms, and each lifting mechanism is synchronously driven by two motors to rotate their respective wire rope drums, Then the lifting hook is lifted through the multi-stage deceleration of the movable pulley block. The frequency conversion and speed regulation transmission scheme of the lifting mechanism adopts the "one drive one" scheme of one frequency converter with one motor. In order to improve the dynamic characteristics and high torque output capacity during low-speed transmission, it has high elastic performance and will not generate in vacuum. Each motor adopts the speed closed-loop control with pulse encoder. The master-slave control scheme with power balance and speed synchronization control function provided by Zhongke frequency converter is adopted between the two frequency converters of each lifting mechanism. These control schemes can realize the accurate torque balance distribution of two motors and the speed synchronization of two lifting mechanisms

3.3 translational drive control

the translational mechanism of crane is divided into cart mechanism and trolley mechanism. The two mechanisms generally adopt the transmission scheme of multiple motors. Due to the large moment of inertia of the translation mechanism of the crane, in order to accelerate the motor, a large starting torque is required. Therefore, the output power of the motor shaft required by the translation mechanism of the crane should be composed of load power and acceleration power, that is:

since the translation mechanism adopts the general v/f open-loop frequency control mode of one inverter dragging multiple motors, when selecting the capacity of the frequency converter, Also meet the following formula:

where - current waveform correction coefficient (1.05-1.1 in PWM modulation mode)

- rated output current of frequency converter, a

- rated current of single motor in power frequency power supply, a

- number of electric motors driven by one frequency converter

because in the "one drive many" general v/f open-loop frequency control mode of frequency converter, The electronic thermal relay protection function provided by the frequency converter cannot realize the overload protection of a single motor. Therefore, a low-voltage circuit breaker with thermal overload protection function is connected in series in each motor circuit to realize the overload protection of a single motor. The motor fault signal is taken from the auxiliary contact of the low-voltage circuit breaker

3.4 selection of delta inverter

delta ve series inverter combines the requirements of the control function of the system, with the characteristics of low price, high quality, dry resistance and durability, easy to realize analog quantity control, and is also suitable for use in harsh carbon environment. Its reconstruction cost is low. The parameters of the frequency converter used in the crown block reconstruction are as follows:

(1) vfd150v43a-2 15kw 20HP 32A 380V 50Hz is selected as the crane frequency converter

(2) vfd055v43a-2 5.5kw 7.5HP 16A 380V 50Hz is selected as trolley frequency converter

(3) one vfd075v43a-2 7.5kw 10HP 22a 380V 50Hz is selected as the lifting frequency converter

4 realization of electric control system

4.1 principle design of electric control system

frequency conversion and speed regulation control system is mainly composed of delta ve series frequency converter, ES series PLC and double handle linkage console. PLC collects handle controller signals, makes logical judgment through the program, and adjusts the output of the frequency converter according to the judgment results to control the direction, speed and torque of the drive motor, Replace the traditional wound rotor series resistance speed regulation drive system. The frequency converter band brake drive control is shown in the figure

Figure 2 principle of electric control system

4.2 parameter debugging of electric control system

in this system, the parameters of vfd-ve frequency converter are mainly as follows:

(1) lifting frequency converter:

parameters of elevator frequency converter:

f=20hz =0 (running in VF mode)

=2 (acceleration time 2s)

=2 (deceleration time 2s)

=42 (crown block action)

=3hz, =20% (when the output frequency is>3hz and the output current is>20%, the crown block acts to open the package brake)

=4hz, =30% (when the output frequency is 3Hz and the output current is>20%, the crown block acts to open the package brake)

=4hz, =30% (when the output frequency is 3Hz and the output current is>20%, the crown block acts to open the package brake)

=4hz, =30% (output frequency