{"id":15370,"date":"2026-01-03T21:30:41","date_gmt":"2026-01-03T13:30:41","guid":{"rendered":"http:\/\/www.erun-tech.com\/?post_type=dt_portfolio&p=15370"},"modified":"2026-01-06T11:00:42","modified_gmt":"2026-01-06T03:00:42","slug":"tongbubiaofashoudongzhuntongbubingche-fuzaizhuanyijifenpeishoudongjieliecaozuo","status":"publish","type":"dt_portfolio","link":"http:\/\/www.erun-tech.com\/en\/project\/tongbubiaofashoudongzhuntongbubingche-fuzaizhuanyijifenpeishoudongjieliecaozuo","title":{"rendered":"Synchronization Table Method: Manual Synchronization and Coupling, Load Transfer and Distribution, Manual Decoupling Operations"},"content":{"rendered":"

Synchronized table method manual quasi-synchronized parallelism,<\/b><\/strong>\u00a0Load transfer and distribution, manual unlisting operations<\/b><\/strong><\/p>\n

I. Synchronous generator parallelism<\/b><\/strong><\/p>\n

 <\/p>\n

1. Grid status check before connection (assuming that generator No. 1 is running on the grid at this time, and generators No. 2 and 3 are on standby)<\/p>\n

(1) The operating mode of the power station is in the normal state, i.e., the mode selector switch is turned to the \u201cMANU\u201d position, as shown in Figure 2-1.<\/p>\n

\"4eec267b5b68d20f8b6de0ede8770822-1\"<\/p>\n

Figure 2-1<\/b><\/strong>\u00a0Working Mode Selection<\/b><\/strong><\/p>\n

(2) Make sure that the voltage and frequency of generator No. 1 are normal, as shown in Figure 2-2. If the frequency and voltage deviate, make adjustments accordingly.<\/p>\n

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Figure 2-2<\/b><\/strong>\u00a0Electrical Instrumentation<\/b><\/strong><\/p>\n

(3) Observe the power of the generator running on the grid, if it is greater than 80% of its stand-alone power, the standby unit must be started.<\/p>\n

2.<\/b><\/strong>Start-up of standby units<\/b><\/strong><\/p>\n

(1) Combine the utilization and electromechanical status of generators No. 2 and No. 3 and select one as a standby unit (assuming that generator No. 2 is selected in this case).<\/p>\n

(2) Check that the No. 2 generator has the following starting conditions: cooling water, lubricating oil, fuel oil, and starting air supply. Verify that the \u201cLOCAL\/REMOTE\u201d selector switch on the side control panel is in the \u201cREMOTE\u201d position. Verify that the unit's \u201cREADY FOR START\u201d light on the main switchboard remains on.<\/p>\n

(3) When manual parallelization is required, press the \u201cENGINE START\u201d button of generator No. 2, as shown in Fig. 2-3, start the standby unit, and wait until the unit accelerates to a speed close to the rated speed and runs steadily for a few minutes. Observe whether the voltage and frequency of the generator to be combined are normal. The voltage does not need to be adjusted because of the automatic voltage regulator (AVR). The speed of the generator to be connected can be manually adjusted so that its frequency is the same as the grid frequency or a little higher.<\/p>\n

\"Figure

Figure 2-3 Generator Start-Stop Control<\/p><\/div>\n

3.<\/b><\/strong>\u5e76<\/b><\/strong>\u00a0\u8f66<\/b><\/strong>\u00a0(<\/b><\/strong>\u00a0\u4f7f<\/b><\/strong>\u00a0\u7528<\/b><\/strong>\u00a0\u540c<\/b><\/strong>\u00a0\u6b65<\/b><\/strong>\u00a0\u8868<\/b><\/strong>\u00a0)<\/b><\/strong><\/p>\n

(1) Turn on the synchronization table to select the generator to be merged, as shown in Fig. 2-4, the synchronization table detects the size, direction and phase difference of the frequency difference between the grid and the generator to be merged. The direction of rotation of the synchronization table pointer depends on the direction of the frequency difference, clockwise means that the frequency of the generator to be connected is higher than the grid frequency. The rotation speed of the synchronization table pointer indicates the size of the frequency difference, and the rotation period is inversely proportional to the frequency difference, for example, when the required frequency difference is equal to 0.25 Hz, the rotation period should be 4s. The phase difference is constantly changing, and the position of the synchronization table pointer indicates the instantaneous phase difference, e.g. the 11 o'clock position represents a phase difference of 30\u00b0, while the 6 o'clock position represents the reverse phase (180\u00b0 phase difference).<\/p>\n

\"Figure

Figure 2-4 Synchronization Table Selection<\/p><\/div>\n

(2) The actual parallel requires the generator to be connected at a slightly higher frequency of 0.2~0.33 Hz, so the synchronization meter pointer should be adjusted to 3~5s clockwise rotation. In the case of anticlockwise rotation (the frequency of the generator to be merged is less than the grid frequency), the generator to be merged and the grid frequency is 0.2~0.33 Hz higher than the grid frequency.<\/p>\n

 <\/p>\n

 <\/p>\n

Electrical and Electronic Operator Practical Assessment I<\/p>\n

Ship power station operation and maintenance, ship electrical and electronic management and technology<\/p>\n

After entering the grid, the reverse power will occur and lead to the failure of merging. If the frequency difference is too large (the rotation period of the pointer is less than 2s, and the frequency difference is more than 0.5 Hz), the residual kinetic energy of the unit with high rotational speed is very large, and the torque generated by the two machines is not enough to pull them into the same step, and as a result, the out-of-step generates a large shock and leads to tripping and power failure.<\/p>\n

(3) The actual parallel requires a phase difference of 15\u00b0 or less, and the same phase point is at 12 o'clock. There is a certain delay time from pressing the closing button to actually closing the main switch, so it should be closed a little earlier, so the closing moment is generally set at 11 o'clock. The requirement of phase difference is higher for the parallel vehicle, and a large phase difference will lead to excessive inrush current, which will not only cause the failure of the generator to be merged, but also cause the power supply unit to trip, resulting in the loss of power of the whole ship. It is absolutely forbidden to close the gate around 180\u00b0.<\/p>\n

(4) After successful closing, as shown in Figure 2-5, the synchronization table should be disconnected in time. Because the synchronization table for short-time working system, the working time can not exceed 15 min.<\/p>\n

(5) The load should be transferred in time after successful parallelization.<\/p>\n

\"Figure

Figure 2-5 Parallel operation of generators<\/p><\/div>\n

II. Load transfer and distribution of parallel units<\/b><\/strong><\/p>\n

(1) just merged with the car, frequency regulation load, as shown in Figure 2-6. From the power table can be seen, just access to the generator power meter pointer is close to zero, not yet with the load, by adjusting the speed control knob of the two generators, so that just merged into the generator acceleration, the original generator on the network deceleration, in the conditions of maintaining the convergence of the frequency for the rated value of the conditions, so that the two units to equalize the load.<\/p>\n

\"Figure

Figure 2-6 Speed Adjustment<\/p><\/div>\n

III. Relevant knowledge<\/b><\/strong><\/p>\n

 <\/p>\n

1. What conditions do I need to fulfill to merge vehicles?<\/p>\n

(1) The rms value of the voltage of the generator to be connected, U\u2082, is equal to the rms value of the voltage of the operating generator, U\u2082 = U\u2081.<\/p>\n

(2) The frequency f\u2082 of the generator to be connected is equal to the frequency f of the operating generator, i.e., f\u2082 = f\u2081.<\/p>\n

(3) The phase \u03b4\u2082 of the voltage of the generator to be connected coincides with the phase \u03b4\u2081 of the voltage of the operating generator, i.e., \u03b4\u2082 = 81.<\/p>\n

(4) The phase sequence of the generator voltage to be connected is the same as that of the operating generator voltage (the phase sequence of the actual generator voltage has already been determined during installation and commissioning, so there is no need to judge at this time).<\/p>\n

If there is a big difference between the parameters, a large inrush current will be generated. If the inrush current is too large, it will result in the failure of parallelization, and in serious cases, it will lead to the power outage of the whole ship, or even cause the damage of the generator set.<\/p>\n

2. What is pull-in synchronization?<\/b><\/strong><\/p>\n

When the generator is connected, any of the connection conditions at the moment of closing are not satisfied, and an inrush current will be generated between the generator sets.<\/p>\n

(1) The reactive component of the inrush current acts as a voltage equalizer.<\/p>\n

(2) The active component of the inrush current acts as a whole step. The whole step power corresponding to the whole step torque, for the generator ahead of the blocking torque, so that the speed down; for the lagging generator is the driving torque, so that the speed up, and ultimately pull the two machines into the same phase synchronous operation. This process is called pull-in synchronization.<\/p>\n

3.<\/b><\/strong>How do I use the light method to merge?<\/b><\/strong><\/p>\n

(1) Light and dark method<\/p>\n

The principle of light and dark method shown in Figure 2-7, assuming that the generator voltage amplitude is the same (easier to achieve in practice), when the generator voltage and grid voltage to be consistent with the phase, the voltage difference is theoretically 0, the lights are off; when the two voltages are anti-phase phase, then the voltage difference is the largest, the light is brightest. When the phase difference changes from 0 to 180\u00b0, the brightness of the lamp changes according to dark, brightest, dark flicker. The speed of flashing indicates the magnitude of the frequency difference, and extinguishing indicates that the phase angle is coincident (i.e., the phase is the same), and the gate can be closed at this time.<\/p>\n

\"Figure

Figure 2-7 Principle of the light and dark method<\/p><\/div>\n

Disadvantages of the light and dark method: the speed of the bright and dark flashes can only indicate the size of the frequency difference, and cannot indicate the positive or negative of the frequency difference. In addition, the bulb actually goes off when the voltage difference is less than 0. Therefore, some prediction of the closing moment is required.<\/p>\n

(2) Light rotation method<\/p>\n

The principle of the light rotation method is shown in Figure 2-8, three lights go out in turn, producing a rotating vision. The operator thus determines the frequency of the parallel side relative to the grid side of the high and low, and accordingly decides whether the generator is down-speed operation or up-speed operation. The middle light is off, indicating that the phase is the same (i.e., phase angle coincidence) can be closed into the generator.<\/p>\n

\"Figure

Figure 2-8 Principle of the light rotation method<\/p><\/div>","protected":false},"excerpt":{"rendered":"

Synchronous Table Method for Manual Semi-Synchronous Coupling, Load Transfer and Distribution, Manual Decoupling Operations I. Synchronous Generator Coupling 1. Pre-coupling Grid Status Inspection...<\/p>","protected":false},"author":1,"featured_media":15380,"comment_status":"open","ping_status":"closed","template":"","dt_portfolio_category":[891],"dt_portfolio_tags":[],"class_list":["post-15370","dt_portfolio","type-dt_portfolio","status-publish","has-post-thumbnail","hentry","dt_portfolio_category-dianzidianqiyuanshicaopinggukecheng","dt_portfolio_category-891","description-off"],"_links":{"self":[{"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio\/15370","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio"}],"about":[{"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/types\/dt_portfolio"}],"author":[{"embeddable":true,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/comments?post=15370"}],"version-history":[{"count":1,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio\/15370\/revisions"}],"predecessor-version":[{"id":15500,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio\/15370\/revisions\/15500"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/media\/15380"}],"wp:attachment":[{"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/media?parent=15370"}],"wp:term":[{"taxonomy":"dt_portfolio_category","embeddable":true,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio_category?post=15370"},{"taxonomy":"dt_portfolio_tags","embeddable":true,"href":"http:\/\/www.erun-tech.com\/en\/wp-json\/wp\/v2\/dt_portfolio_tags?post=15370"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}