变频电机保护信号传输方式的研究及应用

Research and application of signal transmission method for variable frequency motor protection

在聚酯工艺流程中都是采用变频精准控制转速的电机,且重要流程点的变频控制电机是使用强冷风扇降温和PTC热保护继电器保护电机,在日常检查变频电机强冷风扇运行状态和电机温度保护PTC继电器信号时,主要靠人工巡检来完成,但由于人工巡检的时间是阶段性的,故障发生时很容易存在不能及时发现并处理的情况,给稳定生产带来了很大的安全隐患。针对此问题本文进行了相关的研究。研究结果表明,(1)根据目前电机变频器的控制单元CU240E-2 DP丰富的参数进行深入探索,通过备用IO点将外部信号接入控制单元经过内部组态,在其原有的通信基础上将增加2个经控制单元内部组态的外部信号传入DCS系统以实现24小时实时监控。(2)方案在聚酯一项目中实际应用表明,所有电机强冷风扇和PTC继电器信号传送到DCS系统,组态出报警信号,最终实现了在操作站进行实时监控。

In the polyester process,variable frequency precision control motors are used to control the speed,and the variable frequency control motors at important process points use strong cooling fans for cooling and PTC thermal protection relays to protect the motors.In daily inspections of the operation status of the strong cooling fan of the variable frequency motor and the PTC relay signal for motor temperature protection,manual inspections are used to complete the task.However,due to the phased nature of manual inspections,It is easy to encounter situations where faults cannot be detected and dealt with in a timely manner,which poses significant safety hazards to stable production.This article has conducted relevant research on this issue.The research results indicate that(1)based on the rich parameters of the control unit CU240E-2 DP of the current motor frequency converter,in-depth exploration is carried out.External signals are connected to the control unit through backup IO points for internal configuration.On the basis of its original communication,two external signals from the internal configuration of the control unit are added to the DCS system to achieve 24-hour real-time monitoring.(2)The practical application of the plan in the polyester project shows that all motor forced cooling fans and PTC relay signals are transmitted to the DCS system,configured with alarm signals,and ultimately achieved real-time monitoring at the operating station.