introduction: Power supply is the heart of information systems and electronic products; the quality of AC power determines whether these systems and products can function properly. Therefore, understanding AC power supply quality issues is crucial for providing effective solutions. Common AC power supply quality problems include: 1. Excessive voltage fluctuations: Insufficient grid power, reduced voltage supply by the power company, or excessive losses in remote areas can lead to low voltage. Insufficient grid power consumption results in high voltage; low voltage prevents loads from functioning properly, while excessive voltage shortens load lifespan or burns out the load. 2. Waveform distortion (or harmonic distortion): Common waveform distortion refers to various harmonics in the standard power supply waveform. Grid harmonics are generated by the use of switching power supplies in power electronic equipment and electrical appliances such as rectifiers and UPS power supplies, or by the secondary power supply itself. The main hazards of harmonics to the public power grid include: 1) Inducing additional harmonic losses in components of the public power grid, reducing the efficiency of power generation and transmission equipment. When a large amount of third harmonics flows through the neutral line, it can cause line overheating or even fire; 2) Affecting the normal operation of various electrical equipment. In addition to causing additional losses, it can also cause mechanical vibration, noise, and overvoltage in motors, severe local overheating in transformers, and overheating, insulation aging, and shortened lifespan of equipment such as capacitors and cables, leading to damage; 3) Causing local parallel and series resonance in the public power grid, thereby amplifying harmonics and greatly increasing the aforementioned hazards, even causing serious accidents; 4) Causing malfunctions in relay protection and automatic devices, and inaccurate measurement of electrical measuring instruments; 5) Interfering with nearby communication systems, ranging from noise and reduced communication quality to information loss and malfunction of the communication system. 3. Power surges refer to an instantaneous (within milliseconds) output voltage effective value exceeding 110% of the rated value, lasting for one or several cycles. Power surges are a major culprit in damaging precision electronic equipment. Besides lightning strikes, they are primarily caused by high voltage surges generated when large electrical equipment connected to the power grid is switched on or off, due to the sudden unloading of the grid. 1) The effects of power surges on sensitive electronic and electrical equipment include: Damage: Voltage breakdown of semiconductor devices; damage to the metallized surface of components; damage to printed circuit board traces or contacts; damage to triacs/thyristors… Interference: Lock-up, thyristor or triac malfunction; partial corruption of data files; errors in data processing programs; errors and failures in receiving and transmitting data; unexplained malfunctions… Premature aging: Premature aging of components, significantly shortened lifespan of electrical appliances; decreased output sound and picture quality. 2) Which electrical equipment can be damaged by power surges? Electrical equipment containing microprocessors is highly susceptible to damage from power surges. This includes computers and auxiliary equipment, program-controlled exchanges, broadcast television transmitters, film and television equipment, microwave relay equipment; and products in the home appliance industry, including televisions, washing machines, and refrigerators. Survey data shows that 63% of electrical equipment malfunctions during the warranty period are caused by power surges. 4. **Voltage Spikes (or High-Voltage Spikes)** refer to voltage spikes with a peak value of 6000V and a duration ranging from one ten-thousandth of a second to 10ms. These are mainly caused by lightning strikes, electric arcing, static discharge, or the switching operation of large electrical equipment. Their main hazards include: when the spike amplitude is large, it can damage the input filter, rectifier, and even the main oscillator of the industrial control computer's switching power supply. Furthermore, its wide frequency spectrum can also cause interference in the computer. 5. **Transient Overvoltage and Temporary Overvoltage** refer to pulse voltages with a peak value as high as 20000V, but a duration ranging from one millionth of a second to one ten-thousandth of a second. Their main causes and potential damage are similar to high-voltage spikes, primarily caused by lightning. Its main hazards are: Advanced electronic devices such as measurement, monitoring, communication, and computer networks, with large-scale integrated circuits as their core components, are widely used in various fields of modern life. These electronic devices, composed of large CMOS integrated components, generally have a weak ability to withstand transient overvoltages and overcurrents. Transient overvoltages can not only cause malfunctions in electronic devices, or cause interference, data loss, or temporary paralysis; in severe cases, they can cause component breakdown and circuit board burnout, paralyzing the entire system. 6. Voltage sag/brownouts refer to a low-voltage state where the effective value of the mains voltage is between 80-85% of the rated value, and the duration is one to several cycles, or even longer. Causes include: startup and application of large equipment, startup of large motors, or connection of large power transformers, main power line switching, line overload, etc. Its main hazards are: Voltage sag is the most common power problem, accounting for 87% of power problems. Its impact on computers ranges from causing interface devices to stop working to data loss and file corruption. Voltage sags can also damage computer components, shortening their lifespan. 7. Three-phase voltage imbalance refers to unequal voltages or phase angles between phases, caused by unbalanced loads. The relevant standard stipulates that the allowable unbalance at the point of common coupling in normal operation is 2%, and it should not exceed 4% for short periods. Harm to transformers: Three-phase load imbalance causes transformers to operate asymmetrically, increasing transformer losses (including no-load and load losses). According to transformer operation regulations, the neutral current of a transformer in operation should not exceed 25% of the rated current on the low-voltage side. Furthermore, unbalanced three-phase load operation can cause excessive zero-sequence current in the transformer, leading to increased localized metal component temperatures and even transformer burnout. Impact on electrical equipment: Three-phase voltage imbalance can result in current imbalance several times greater. This induces increased reverse torque in motors, causing their temperature to rise. Imbalance between phases shortens the lifespan of electrical equipment and increases maintenance costs. The reduced current margin of circuit breakers makes them prone to overload and short circuits when loads change or alternate. Excessive unbalanced current flowing into the neutral conductor causes it to thicken. This affects line loss. In a three-phase four-wire system, line loss is minimal when the three-phase load is balanced; the increase in line loss is small when one phase is heavily loaded and two phases are lightly loaded; however, when the three-phase load is unbalanced, the current is unbalanced regardless of the load distribution, leading to increased line loss. 8. Noise refers to radio frequency interference (RFI), electromagnetic interference (EFI), and other high-frequency interference. Originating from electromagnetic waves or high-frequency wave induction, it is a high-frequency variation, ranging from 15-100% potential fluctuation at the normal 50Hz power frequency. Motor operation, circuit breaker operation, motor controller operation, broadcast transmission, microwave radiation, and electrical storms all cause noise. Its main hazards are: excessive noise may cause misjudgments by the computer CPU, and in severe cases, may burn out the CPU and other computer components, and may cause radio transmission interruptions. Induction conduction to the surrounding environment can cause other electronic devices to malfunction. This can lead to the failure of civil aviation systems, communication disruptions, computer errors, and malfunctions of automated equipment. The Aoqis AC parameter power supply integrated regulator plays a crucial role in improving the power quality of the distribution network. This device has the following functions: 1) Maintaining a constant load-side voltage under conditions of primary-side voltage fluctuations or short-term power outages of 2-3 cycles. 2) Maintaining three-phase voltage balance on the load side under conditions of primary-side voltage imbalance and harmonics. 3) Compensating for load-side current harmonics and reactive power, ensuring the grid side only provides active current. 4) Compensating for load-side unbalanced current harmonics, ensuring three-phase balance of the grid-side current. 5) Eliminating various microscopic power source interference pollution.