发电机故障排除没有实质性进展，本次主要针对发电机的电路部分和机械部分进行了深入探讨。
首先，我们对发电机脱扣电路部分进行了详细分析。从下图可以看出，发电机脱扣有四个主要原因，只要其中任何一个原因得电，辅助触点脱开，发电机就会分闸。
Firstly, we conducted a thorough examination of the generator's tripping circuitry. As illustrated in the figure below, there are four primary reasons for the generator to trip. Should any one of these causes become energized, the auxiliary contact will open, leading to the generator tripping.
第一，K283.31辅助触点与岸电有关。当岸电接入后，三台发电机是不允许合闸的，形成一个互锁。当时没有进行岸电操作，因此这个原因很容易被排除。
The auxiliary contact K283.31 is associated with shore power. Once shore power is connected, it is prohibited for the three generators to be closed, creating an interlock. As no shore power operations were conducted at the time, this cause can be readily dismissed.
第二，K111.7辅助触点是浮差触点。根据分析，一号和二号发电机共用一个浮差触点，三号发电机单独使用一个，两个同时出现问题的可能性较小。同时，这个触点动作后，我们在配电盘外部是无法复位的，需要专门的复位操作。当时我们只是在配电盘外部将ACB ABNORMAL RESET后，就可以合闸，说明这个辅助触点并未触发。
The auxiliary contact K111.7 is a differential contact. Chief Wang had previously mentioned during discussions that this fault could potentially cause the generator to trip. Upon analysis, NO.1&2 share a single differential contact, while NO.3 G/E has a separate one. The likelihood of both encountering issues simultaneously is quite low. Moreover, once this contact is actuated, it cannot be reset from outside the switchboard and requires a specific reset procedure. At the time, we were only able to close the circuit after performing an ACB ABNORMAL RESET from outside the switchboard, indicating that this auxiliary contact did not trigger.
第三，CON-16 DG1 ABN TRIP触点是发电机在不正常的情况下导致发电机不正常跳闸，会有报警。例如，欠压保护、缺相保护、长延时和短延时等，都会导致发电机TRIP，这个应该可以在发电机控制屏上找到报警记录。如果低电压和低频率时间不够长，是不会报警，也是直接ACB TRIP.
The contact CON-16 DG1 ABN TRIP is for the generator to trip abnormally under abnormal conditions, which would set off an alarm. For example, under voltage protection, phase loss protection, long-time delay, and short-time delay can all lead to a generator TRIP. This should be recorded in the generator control screen's alarm log. But if the low voltage and low frequency do not persist for a sufficient duration, there will be no alarm; instead, it will directly cause an ACB TRIP.
第四，K152.62辅助触点是发电机安保系统给出的信息，发电机才会进行stop/shutdown，详见下图Fig2。本次因为发电机没有停机，所以可以不考虑shutdown的报警，例如滑油低压这样的就不用考虑了。
The auxiliary contact K152.62 is an information signal from the generator's security system that would lead the generator to perform a stop/shutdown. Please refer to the figure below for details. Figure 2. Since the generator did not stop this time, we can disregard shutdown alarms, such as low lubricating oil pressure.
Fig2
其次，我们讨论了发电机的信号干扰问题。尽管发电机线路已经全部进行了包扎和装铠甲，但这也不是百分之百的。这个问题的查找会比较麻烦。
Secondly, we discussed the issue of signal interference with the generator. Although all generator wiring has been wrapped and armored, this is not a foolproof solution. Identifying this issue will be quite challenging.
再次，我们讨论了发电机PLC控制板的问题。分析认为，PLC不存在死机现象。因为当时24V电一直在给发电机供电，如果控制屏没有重启，死机现象就会一直存在。但我们当时进行并电操作都没有问题；现在看到控制屏上的数据都在实时更新，也可以排除PLC死机的可能。
Thirdly, we addressed the issue of the generator's PLC control board. The analysis suggests that there is no PLC crash. Since the 24V power supply was continuously provided to the generator, if the control screen did not reboot, the crash would persist. However, we encountered no issues during parallel operation; the data on the control screen is now updating in real-time, which also rules out the possibility of a PLC crash.
最后，我们对发电机ACB主空气开关进行了分析。从二号和三号发电机合闸的情况看，发电机是进行了合闸再分闸。三号发电机合闸时间为15秒，当时的负荷值为19.7%；二号发电机合闸时间为10秒，负荷为31.5%。通过计算，0.197*1250=146KW；0.315*1250=393KW。从Fig3来看，三号发电机启动到了15秒，到了启动主海水泵阶段；二号发电机到了启动低温淡水泵阶段。二号的负荷不应该比三号大。这说明可能有大的设备启动或过电流。如果海水泵卡住，不进行复位，是不可能自动恢复的。但现在所有设备都是正常的。
因此怀疑，当时应该是发电机给了主空气开关脱扣信号。从跳电到现在也将近一周时间，发电机已经在使用，也没有发现什么问题。
因此，建议我们三台发电机轮流使用，看是否还会出现类似问题。另一个建议是在安全的情况下，再次进行一号发电机分闸，让二、三号发电机重新并电进行测试。
Lastly, we analyzed the generator's ACB main air switch. Observing the closing and tripping of NO.2&3, it appears that the generator closed and then tripped. NO.3 G/E closed for 15 seconds with a load value of 19.7%; NO.2 G/E closed for 10 seconds with a load of 31.5%. By calculation, 0.197 * 1250 = 146KW; 0.315 * 1250 = 393KW. From Figure 3, it can be seen that NO.3 G/E initiated for 15 seconds, reaching the stage of starting the main seawater pump; NO.2 G/E reached the stage of starting the low-temperature freshwater pump. The load on NO. 2G/E should not be greater than that on NO.3 G/E. This indicates that there may have been a significant equipment start-up or overcurrent. If the seawater pump were jammed and not reset, it would not recover automatically.
However, all equipment is currently operational. Therefore, we suspect that the generator issued a tripping signal to the main air switch at that time. Since the power outage, which has been nearly a week, the generator has been in use without any issues.
Therefore, it is recommended that we rotate the use of the three generators to see if similar issues will arise again. Another suggestion is to, under safe conditions, trip NO.1 G/E again and allow NO.2&3 G/E to re-parallel for testing.
Fig3
之后，我们讨论了发电机的燃油系统和供气系统。因为刚刚加注完成，开始加注时，可能惰化中存在氮气，导致燃气不纯，也有可能发生gas trip。我们开始加注的管路中确实会存在一定的氮气。因此建议开始使用时，特别是在刚刚出马六甲海峡的时候，尽量不要使用燃气。因为他不是发电机方面的服务商，他还是建议将一号发电机油压降低，同时燃气升高的曲线交给发电机服务商分析。从曲线来看，燃油和燃气是否同时存在共进的问题？是否是发电机控制电路板问题，发现异常，给出信号，只是分闸保护发电机，而没有停机信号。
Following up on our previous discussion, we then delved into the fuel and air supply systems of the generator. Engineer Zhang posited that, given the recent refueling, there might have been nitrogen in the inert gas during the initial fueling process, leading to impure gas and potentially causing a gas trip. It is true that our refueling lines would contain a certain amount of nitrogen. Therefore, it is recommended to avoid using gas, especially when just exiting the Straits of Malacca. As he is not a service provider specializing in generators, he suggested handing over the curve showing the decrease in oil pressure and the increase in gas pressure of NO.1 G/E to the generator service provider for analysis. From the curve, we need to determine if there is a simultaneous co-feeding issue with fuel and gas, and whether it could be a problem with the generator's control circuit board that detects anomalies and sends signals to trip the generator for protection without issuing a shutdown signal.
同时，我们询问了服务商，是否可以从PLC控制面板和发电机控制屏调取发电机电流、电压和频率等参数？他说我们这种发电机里面是没有的。这又是分析是否存在过流、缺相和欠压等重要数据的关键。
Additionally, I inquired with service Engineer about the possibility of retrieving parameters such as current, voltage, and frequency from the PLC control panel and generator control screen. He informed us that our type of generator does not have this capability. This is crucial data for analyzing potential issues such as overcurrent, phase loss, and under voltage.
以上是我们最近分析的结果，还有几个疑问待解决：什么原因导致发电机自动脱扣信号给发电机，而不停机关？另外，gas trip后，什么节点燃油接管？是否存在燃油和燃气共进的时刻？如果gas trip，调速器没有跟上，导致发电机跳电是否有这种可能性？
The above are the results of our recent analysis, and we still have several questions to resolve: What causes the generator to send an automatic tripping signal without shutting down the engine? Additionally, after a gas trip, at what point does the fuel take over? Is there a moment when fuel and gas are co-delivered? Is it possible that if a gas trip occurs and the governor does not respond in time, it could cause the generator to trip?
同时也感谢热心的同仁在文章后面的留言，确实给我们很好的建议。非常感谢！
We also appreciate the enthusiastic colleagues who have left comments after the article, which indeed provided us with valuable suggestions. Thank you very much!
