IN AN AC CIRCUIT, THERE ARE TWO TYPES OF POWER SOURCES PROVIDED TO THE LOAD; IT IS A POSITIVE FORCE AND A REACTIVE POWER. ACTIVE POWER IS THE ELECTRICITY THAT NEEDS TO MAINTAIN THE NORMAL OPERATION OF ELECTRICAL EQUIPMENT AND CONVERT ELECTRICAL ENERGY INTO OTHER FORMS OF ENERGY (MECHANICAL ENERGY, SOLAR ENERGY, THERMAL ENERGY). FOR EXAMPLE, A 5.5 KW MOTOR CAN CONVERT 5.5 KW OF ELECTRICAL ENERGY INTO MECHANICAL ENERGY, AND A WATER PUMP OR THRESHER CAN BE USED FOR THRESHING; VARIOUS LIGHTING DEVICES CONVERT ELECTRICAL ENERGY INTO LIGHT ENERGY, PROVIDING LIGHTING FOR PEOPLE'S DAILY LIFE AND WORK. THE SYMBOL FOR ACTIVE POWER P REPRESENTS UNITS OF WATTS (W), KILOWATTS (KW), AND MEGAWATTS (MW). REACTIVE POWER IS RELATIVELY ABSTRACT, IT IS USED FOR THE EXCHANGE OF ELECTRIC AND MAGNETIC FIELDS WITHIN A CIRCUIT, AND FOR SETTING AND MAINTAINING THE MAGNETIC FIELD OF ELECTRICAL EQUIPMENT. IT DOESN'T WORK.ALL ELECTROMAGNETIC COILS OF ELECTRICAL EQUIPMENT, CREATING A MAGNETIC FIELD, WILL CONSUME REACTIVE POWER. A 40 WATT FLUORESCENT LAMP, IN ADDITION TO CONSUMING MORE THAN 40 WATTS OF ACTIVE POWER, ALSO NEEDS TO CONSUME A PORTION OF THE ACTIVE POWER (BALLAST) TO EMIT LIGHT, REQUIRING ONLY ABOUT 80 REACTIVE LOAD COILS TO ESTABLISH AN ALTERNATING MAGNETIC FIELD. BECAUSE IT IS NOT ISOTHERMAL, IT IS CALLED 'ACTIVE'. REACTIVE POWER Q, SYMBOLIZING UNIT FLOWER (VAR) OR KILOVOLT AMPERE (KILOVOLT AMPERE). REACTIVE POWER IS BY NO MEANS USELESS, IT HAS IMPORTANT USES. AN ELECTRIC MOTOR NEEDS TO ESTABLISH AND MAINTAIN A ROTATING MAGNETIC FIELD TO MAKE THE ROTOR ROTATE, THEREBY DRIVING MECHANICAL MOTION. OBTAINING THE MAGNETIC FIELD OF THE MOTOR ROTOR FROM THE POWER SOURCE IS REACTIVE POWER. REACTIVE POWER TRANSFORMERS AND THE MAGNETIC FIELD OF TRANSFORMER COILS ARE ALSO REQUIRED.REACTIVE POWER SUPPLY AND ELECTRICITY GENERATION HAVE SOME ADVERSE EFFECTS, MAINLY MANIFESTED IN: (1) REDUCING THE ACTIVE POWER OUTPUT OF THE GENERATOR. (2) REDUCE THE POWER SUPPLY CAPACITY OF SUBSTATION EQUIPMENT BY DEFEATING. (3) INCREASE THE VOLTAGE LOSS AND POWER LOSS OF THE LINE. (4) THE OPERATION, LOW POWER FACTOR, AND VOLTAGE DROP HAVE NOT FULLY UTILIZED THE CAPABILITIES OF ELECTRONIC DEVICES. THE REACTIVE POWER SUPPLIED FROM GENERATORS AND HIGH-VOLTAGE TRANSMISSION LINES CANNOT MEET THE NEEDS OF THE LOAD, SO SOME REACTIVE POWER COMPENSATION DEVICES NEED TO BE INSTALLED IN THE POWER GRID TO PROVIDE REACTIVE POWER TO ENSURE THE USER'S DEMAND FOR REACTIVE POWER. IT CAN WORK ON ELECTRICAL EQUIPMENT AT RATED VOLTAGE. THIS IS A NECESSARY REACTIVE POWER COMPENSATION DEVICE.