Master everything about capacitor compensation cabinets in one article

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This article provides a professional overview of the functions and working principles of capacitor compensation cabinets, along with the primary circuit diagram, secondary wiring diagram of such cabinets, and the installation procedures for them. It is highly useful for instrument repair technicians and electricians to quickly become familiar with and master the knowledge related to capacitor compensation cabinets. Most of the load types in power systems are inductive loads, and the widespread use of power electronic equipment by electrical consumers results in a low power factor in the grid. A lower power factor reduces equipment utilization, increases investment in power supply infrastructure, deteriorates voltage quality, shortens the lifespan of equipment, and **increases line losses. Therefore, by installing capacitor compensation cabinets in the power system, inductive loads can be balanced and the power factor improved, thereby increasing the utilization rate of equipment. Capacitor compensation cabinet: yunrun.com.cn/tech/2140.html. Functions and working principle of the capacitor compensation cabinet: Its role is to improve the power factor of the load, reduce reactive power, and enhance the efficiency of power supply equipment. It is possible to determine whether the capacitive compensation cabinet is operating properly by checking the reading on the power factor meter; if the reading is around 0.9, it can be considered to be working normally. With the knife-switch fuses and circuit breakers closed, the reactive power compensation controller outputs control signals based on the phase difference between the voltage and current in the incoming line cabinet, thereby controlling the opening and closing of the AC contactors and thus regulating the connection and disconnection of the capacitors. The following figure shows its physical structure and the main circuit diagram of the primary circuit. http://yunrun.com.cn/upload/201808/14/201808142110407065.png Secondary schematic diagram of the capacitor compensation cabinet. The working principle of the secondary circuit is as follows: when operating manually, each time the toggle switch KK moves from position KK21 to KK22, another LED light turns on, indicating that capacitors 1 through 8 come online one after another ； When in automatic mode, if the changeover switch KK stops at position KK1-2, then all positions except the one where it is stopped will be activated. The schematic diagram of the secondary circuit is shown below. http://yunrun.com.cn/upload/201808/14/201808142120285245.png Wiring diagram for the secondary circuit of the capacitor compensation cabinet. The wiring diagram for the secondary circuit is shown below. http://yunrun.com.cn/upload/201808/14/201808142126131101.png The method for reading the diagram is as follows: for example, A611/1: Ua, where A611 is the wire number, 1 is the component number, and Ua is the terminal number of the component ； Another example is 7:5, where 7 represents the component number and 5 represents the component terminal number ； 29: A2, where 29 represents the component number and A2 represents the component terminal number. Installation procedures for the secondary circuit of a capacitor compensation cabinet: ① Tools required: wire strippers, scissors, screwdrivers, crimping pliers, appropriate socket wrenches, needle-nosed pliers, benders, lamp holders, adjustable wrenches, and electrician’s knives. ②According to the diagram, install electrical components of the secondary system such as relays, instruments, signal lights, terminal blocks, etc., along with their accessories. ③Paste the component labels according to the layout diagram; these labels are generally placed on the metal frame in the upper middle part of the component. In cases where it is not possible to place a label above the component, an appropriate location nearby can be chosen for placement. ④Determine the wiring path based on the pattern. Measure along the wiring path, cut the material correctly (usually leaving a length of 300–500 mm), and mark or label both ends; then lay it out according to the wiring path. ⑤The wiring should be laid in a straight and orderly manner, with a neat and clear arrangement; it should be secured using tie straps or wrapping tape. The secondary wires can be laid in plastic trunking designed for wiring; in this case, it is only necessary to organize the wires properly without tying them together. Assembly steps for the capacitor compensation cabinet: Wiring should be carried out following the principle of starting from the left side then the right, from top to bottom, from inside to outside, and tackling the more difficult tasks first. First, connect the reactive power meter, ammeter, and voltmeter ； Then connect the automatic compensator and the universal changeover switch ； After completion, use binding wire to keep it horizontal and vertical with a 90° corner. When wiring the terminal block, leave some slack in the wires; each terminal screw should connect no more than two wires. Then connect the current transformer, AC contactor, and thermal relay.