一个视频看懂如何测量IGBT

设备功率管IGBT测量方法，1、2、3脚分别是G、C、E，用万用表10K欧姆档测量，黑表笔接第2脚，红表笔接第3脚。用手触摸1、2脚导通，触摸1、3脚截止，说明这个功率管是完好的。How to measure the IGBT？Measurement method for IGBT of equipment power transistor, pins 1, 2, and 3 are G, C, and E respectively, measured with a multimeter in 10K ohm range, with the black probe connected to pin 2 and the red probe connected to pin 3. Touch pins 1 and 2 with your hand to turn on, and touch pins 1 and 3 to turn off, indicating that this power transistor is intact.

发布：2025-12-09      浏览：59

一个视频了解光伏的心脏-逆变器

光伏就是把太阳能转化为电能的过程，但太阳能产生的是直流电，而电网传输、设备运行使用的都是交流电，所以需要把直流转化为交流。交流转直流叫整流，直流转交流叫逆变，这个设备是：逆变器。是光伏的核心部件，常用在新能源汽车里。它的转化效率时刻影响着发电效率，把电池的直流转换为交流，以供电机使用。逆变器的重要性堪比燃油车的变速箱，因为它负责控制电流、电压和频率，从而改变电机的转速、扭矩，影响着电机的能耗、马力，对纯电续航和性能影响巨大。 The heart of photovoltaics - invertersPhotovoltaics is the process of converting solar energy into electrical energy, but solar energy generates direct current, while the power grid transmission and equipment operation use alternating current, so it is necessary to convert direct current into alternating current. The conversion of AC to DC is called rectification, and the conversion of DC to AC is called inversion. This device is an inverter. It is the core component of photovoltaics and is commonly used in new energy vehicles. Its conversion efficiency constantly affects the power generation efficiency, converting the DC of the battery into AC for use by the motor. The importance of an inverter is comparable to that of a gearbox in a gasoline car, as it is responsible for controlling current, voltage, and frequency, thereby changing the speed and torque of the motor, affecting its energy consumption and horsepower, and having a huge impact on pure electric range and performance.

发布：2025-12-05      浏览：84

如何云监测高采低补后的PF？

光伏项目中经常采用高采低补的方案，即：采样点在高压侧，通过高压侧的CT、PT，测量计量点的电流电压、PF等参数，补偿设备仍然安装在低压侧400V。PF控制器采集高压侧的数据，分析后判定低压侧无功设备发出或吸收多少无功功率。升压式SVG无功补偿方案由低压SVG（400V或者690V）补偿柜、升压变压器、高压侧电流采样信号及其它辅助电气元件组成。低压SVG实时检测系统电压电流，快速输出补偿无功电流，通过升压变压器变换到高压侧去补偿高压无功功率，从而提升高压母线的PF。需要注意的是：升压变压器一次侧电压必须与高压系统一致，二次侧电压必须与选择的SVG额定电压一致。升压变压器可以为了SVG单独增加，也可利用现场原有的变压器。系统总电流采样的位置可以选择从总进线柜取，也可选择从计量柜取，具体位置需要根据现场实际取样可行性判断。高压电流采样，有的系统是A、B、C三相各相一只互感器，有的只有A、C两相有互感器；有三只互感器的系统，可直接将电流采样信号线引入SVG采样电流互感器接线端子即可。如果现场只有A、C两相有互感器，可以构造出B相电流，然后将三相电流采样引入SVG。 How to monitor the PF after high mining and low replenishment in the cloud?The high sampling and low compensation scheme is often adopted in photovoltaic projects, that is, the sampling point is on the high voltage side, and the current, voltage, PF and other parameters of the measuring point are measured through CT and PT on the high voltage side. The compensation equipment is still installed on the low voltage side 400V. The PF controller collects data on the high voltage side, analyzes it, and determines how much reactive power the low voltage side reactive equipment emits or absorbs.The step-up SVG reactive power compensation scheme consists of a low-voltage SVG (400V or 690V) compensation cabinet, a step-up transformer, a high-voltage side current sampling signal, and other auxiliary electrical components. The low-voltage SVG real-time detection system detects voltage and current, quickly outputs compensating reactive current, and compensates for high-voltage reactive power by converting it to the high-voltage side through a step-up transformer, thereby improving the PF of the high-voltage bus.It should be noted that the primary voltage of the step-up transformer must be consistent with the high voltage system, and the secondary voltage must be consistent with the selected SVG rated voltage. The step-up transformer can be added separately for SVG, or the existing transformer on site can be used. The location for sampling the total current of the system can be selected from the main incoming cabinet or the metering cabinet, and the specific location needs to be determined based on the feasibility of sampling on site.High voltage current sampling, some systems have one transformer for each phase of A, B, and C phases, while others only have transformers for phases A and C; A system with three transformers can directly introduce the current sampling signal line into the SVG sampling current transformer terminal. If only phases A and C have transformers on site, phase B current can be constructed, and then the three-phase current can be sampled and introduced into SVG.

发布：2025-12-03      浏览：102

一个视频记住如何使用万用表

1、测量先看挡，不看不测量每次拿起表笔准备测量时，务必再核对一下测量类别、量程选择开关是否拨对位置。2、测量不拨挡，测完拨空挡测量中不能任意拨动选择旋钮，特别是测高压（如220V）或大电流（如0.5A）时，以免产生电弧，烧坏转换开关触点。测量完毕，应将量程选择开关拨到空挡位置。3、表盘应水平，读数要对正使用万用表应水平旋转，读数时视线应正对着表针。4、量程要合适，针偏过大半选择量程，若事先无法估计被测量大小，应尽量选较大的量程，然后根据偏转角大小，逐步换到较小的量程，直到指针偏转到满刻度的 2/3 左右为止。5、测R不带电，测C先放电严禁在被测电路带电的情况下测电阻。检查电器设备上的大容量电容器时，应先将电容器短路放电后再测量。6、测R先调零，换挡需调零测量电阻时，应先将转换开关旋到电阻挡，把两表笔短接旋“Ω”调零电位器，使指针指零欧后再测量。正常情况下，每次更换电阻挡时，都应重新调整欧姆零点。7、黑负要记清，表内黑接“+”红表笔为正极，黑表笔为负极，但电阻挡上黑表笔接内部电池的正极。8、测I应串联，测U要并联测量电流时，应将万用表串接在被测电路中；测量电压时应将万用表并联在被测电路的两端。9、极性不接反，单手成习惯测量电流和电压时应特别注意红、黑表笔的极性不能接反，并且一定要养成单手操作的习惯，以确保安全。

发布：2025-11-24      浏览：153

切换电容器复合（无弧）接触器有何优势？

在电力系统运行的过程中，电力电容器被广泛应用于改善功率因数、提高电能质量和稳定电压等方面。但是，在切换电力电容器时，需要专用的接触器来实现。下面阐述为什么切换电容器专用接触器拥有卓越的性能和可靠性。一、切换电容器专用接触器的原理是什么？其是一种用于控制电容器切换的电器装置，它通过控制接触器动作来切换电容器的工作状态，以实现对电网功率因数的调节和优化。通常由电磁铁、接触系统和外壳等部分组成。在正常工作状态下，电磁铁处于断电状态，接触器处于分断状态；当需要切换电容器时，电磁铁受到控制信号作用，产生吸合力，使接触器闭合，将电容器接入电网。二、切换电容器专用接触器主要应用在哪里？1、电力系统的配电网和变电站中，用于管理电容器组的运行状态，以维持电网电能质量；2、工业自动化控制器中，用于改善电能质量，提高工作效率，并节省电能；3、切换电容器专用接触器还可应用于复合型电容器组的切换和保护等。三、切换电容器专用接触器的特点是什么？1、高负载能力：能够承受高电压和大电流，具有很高的负载能力；2、快速响应：响应时间短，能够快速切换电容器；3、安全可靠：其外壳采用防护材料制造，能够在高温、高压等恶劣环境下工作，同时还具有防爆、耐火等特点。切换电容器专用接触器作为电容器切换的重要部分，在电力系统以及工业自动化等领域中具有广泛应用前景。其高耐力、高可靠性以及快速响应时间等特点，能够有效地改善电能质量，提高工作效率，为电能质量真正做到保驾护航。实现无弧的原理图（1）新一代高性能、无涌流、无电弧的电容投切交流接触器，是一种晶闸管和机械开关混合的电容投切开关，是目前国内少数能承受八倍额定电流通断 、达到AC3通断能力复合结构的电容投切装置。尤其适用于功率因数补偿滤波电容的频繁准动态投切，是传统电容接触器的升级产品。工业场合中160A的复合（无弧）接触器，能实现过零投切、抵御瞬间电流1000A左右。实现无弧的工作原理为：在接触器接通过程中，晶闸管在两端电压过零时导通，然后机械触点闭合，从而达到无浪涌冲击电流接通电容的目的；在接触器分断的工作过程中，晶闸管在机械触点两端存在一定电位差时导通，接触器机械触头在分断瞬间电流经晶闸管旁路，达到分断无电弧之目的。电容器复合（无弧）接触器图（2）

发布：2025-11-14      浏览：181

串联谐振的原理是什么？

在 RLC 串联交流电路中，流经电感元件与电容元件的电流为同一电流。由于电感电压超前电流90°，电容电压滞后电流90°，所以每时每刻，电感电压总与电容电压相反。当两电压幅值相等（感抗等于容抗）时，其电压叠加值为零，即电感与电容构成的整体可等效视为短路。此时依据欧姆定律，电路电流可直接表示为电压与电阻的比值，且电压与电流相位一致。需注意，电感与电容两端各自存在端电压，其数值可能远高于输入电压，此现象即被定义为串联谐振过电压。What is the principle of series resonance?In an RLC series AC circuit, the current flowing through the inductive and capacitive elements is the same current. Due to the inductor voltage leading the current by 90 ° and the capacitor voltage lagging the current by 90 °, the inductor voltage is always opposite to the capacitor voltage at all times. When the amplitudes of two voltages are equal (inductance equals capacitance), the voltage superposition value is zero, which means that the whole composed of inductance and capacitance can be equivalently regarded as a short circuit. According to Ohm's Law, the current in a circuit can be directly expressed as the ratio of voltage to resistance, and the voltage and current phases are consistent. It should be noted that there is a terminal voltage at both ends of the inductor and capacitor, which may be much higher than the input voltage. This phenomenon is defined as series resonant overvoltage.

发布：2025-11-03      浏览：214

电流互感器二次为什么不能开路？

正常运行时，二次电流产生的反向磁通抵消一次电流产生的磁通，使得铁芯中总磁通较小，所以二次电压接近为零。若二次断开，二次电流为零，没有反向磁通的抵消，一次电流产生的磁通就是总磁通，急剧变大，二次侧将会出现高达数千伏的电压，此时危险来临。Why Can't the Secondary Side of a Current Transformer Be Open-Circuited?During normal operation, the reverse magnetic flux generated by the secondary current offsets the magnetic flux generated by the primary current. This keeps the total magnetic flux in the iron core relatively small, so the secondary voltage is close to zero. If the secondary side is disconnected, the secondary current becomes zero, and there is no offset from the reverse magnetic flux. The magnetic flux generated by the primary current then becomes the total magnetic flux, which increases sharply. As a result, the secondary side will develop a voltage as high as several thousand volts, and at this point, dangers arise.

发布：2025-10-27      浏览：218

有功功率、无功功率的关系

正常情况下，视在功率是指，容量固定不变，把视在功率看作圆的半径，横轴上投影是有功功率，纵轴上投影是无功功率，夹角就是功率因数角。当夹角为0时，功率因数为1，容量直接等于有功功率，那么当夹角为90°时，是什么情况呢？The relationship between active power and reactive powerUnder normal circumstances, apparent power refers to a situation where the capacity remains constant. Think of apparent power as the radius of a circle, with the projection on the horizontal axis representing active power and the projection on the vertical axis representing reactive power. The angle formed is the power factor angle. When the angle is 0, the power factor is 1, and the capacity is directly equal to the active power. So what happens when the angle is 90°?

发布：2025-10-27      浏览：195

电容并联或串联后的三种状态

相同参数的两个电容并联后，电容的耐压值不变，但是容量翻两倍！相同参数的两个电容串联后，耐压值增加了两倍，但是容量会减半！相同参数的两个有极性电容背靠背反向串联后就组成了无极性电容，电容的耐压值不变，容量值减半！ Three States of Capacitors After Parallel or Series ConnectionWhen two capacitors with the same parameters are connected in parallel, the voltage rating remains unchanged, but the capacitance doubles!When two capacitors with the same parameters are connected in series, the voltage rating triples, while the capacitance is halved!When two polar capacitors with the same parameters are connected in reverse series back-to-back, they form a non-polar capacitor. The withstand voltage value of the capacitor remains unchanged, and the capacity value is halved!

发布：2025-10-21      浏览：187

三次谐波引发零线发热怎么办？

酒店、商超的零线发热问题主要由三次谐波引起，有如下七种治理方案：一、在谐波源附近加装LC无源滤波器、APF有源滤波器；二、更换优质开关电源，降低谐波，提升功率因数；三、调节三相负载，尽可能让每一相负载均匀分布；四、加粗零线，提高零线的过流能力；五、匹配开关电源和负载的功率，避免“大马拉小车”现象；六、在相线上串联电抗器，并定期检查中性线是否松动；七、推荐TN-S接地系统，错峰运行高谐波设备。 ‌How to Fix Neutral Heating by Third Harmonics?The problem of zero line heating in hotels and supermarkets is mainly caused by third harmonic, and there are seven solutions for addressing it as follows:1st、 Install LC passive filters and APF active filters near harmonic sources;2nd、 Replace high-quality switching power supply, reduce harmonics, and improve power factor;3rd、 Adjust the three-phase load to ensure even distribution of each phase load as much as possible;4th、 Bold the zero line to improve its overcurrent capability;5th、 Match the power of the switch power supply and the load to avoid the phenomenon of "big horse pulling small car";6th、 Connect a reactor in series on the phase line and regularly check if the neutral line is loose;7th、 Recommend TN-S grounding system and staggered operation of high harmonic equipment.  ‌

发布：2025-10-20      浏览：194