As power energy shifts from traditional thermal power plants to carbon-free generation, large-scale centralized and distributed power generation from renewable energy sources is developing rapidly. The management and regulation of power quality is becoming increasingly important. Implementing more robust and frequent monitoring can better address voltage quality challenges.
This article provides you with a detailed introduction to power quality-related issues and solutions. It can provide you with better response measures to facilitate the transformation and upgrade of your power, energy, and systems.
1. What Is Power Quality?
2. What Are The Standards In Power Quality?
3. Why We Need To Measure Power Quality?
4. How We Measure Power Quality?
5. What Is Power Conditioning?
6. What Are The Main Factors That May Impact Power Quality?
7. What Are The Effects Of Poor Power Qualities?
8. What Are The Potential Causes Of Poor Power Quality?
9. How To Tackle Power Quality Problems?
10. What Is RFI (EMI) / EMC?
11. What Are The Power Quality Solutions?
12. How To Address Power Quality Issues?
13. What Are The Power Terms For Power Systems?
14. What Are The Power Quality Challenges In The World?
15. What Are The Market Trends For Power Quality?
What Is Power Quality-sourced: electricalworkbook
Power quality is the degree to which the power value delivered to electrical equipment by technical and equipment means matches the expected value. It is mainly determined by two factors: power distribution and power consumption.
In modern power systems, power quality determines the quality and efficiency of electronic equipment operation. When the power quality is higher, the power utilization efficiency and productivity of the equipment are higher.
If the power quality is poor, the downtime of the equipment will increase, the frequency will increase, and the failures will increase. In this case, the utilization rate of power will not be high, resulting in waste of personnel, increased risk of equipment damage, and increased operating costs.
What Are The Standards In Power Quality-sourced: powerquality
In general, the quality of power is mainly determined by the standard voltage. Generally, in low-voltage power grids, the voltage standard is around 100V-130V (US, Canada, Mexico, Japan, Taiwan, China, etc.) and 220V-240V (China, UK, Germany, France, Italy, Australia, South Korea, Singapore, Thailand, etc.), with a frequency of 50Hz.
High-quality power quality can allow a 10% deviation. If your system voltage exceeds this range, the system is prone to low efficiency, and the equipment is easily damaged.
Why We Need To Measure Power Quality-sourced: hioki
In order to improve the power quality of the power system and the utilization efficiency of power equipment, we need to measure the power quality of different systems according to standard conditions.
Due to the increasing popularity of renewable energy, such as electric vehicle chargers, solar energy,y and wind energy in modern society, the power grid system under different conditions has become more complex. In order to better control the power quality and improve the efficiency of power utilization, measuring power quality is a very important technology and reference standard.
There are standard processes and technical guidance for the measurement and evaluation of power quality. This ensures that the measurement results of the power quality of the system are consistent and stable. In order to ensure that different power systems can measure results that meet specific quality and reliability standards, international standards for evaluation and measurement are provided for various power systems.
How We Measure Power Quality-sourced: electrical-engineering-portal
IEC 61000-4-30
This international standard for power quality measurement divides power quality measuring instruments into Class A and Class S. Class A specifies the functions and accuracy of power quality and includes detailed algorithms.
IEC 61000-4-7
This standard specifies international test standards for harmonic currents and harmonic voltages in energy systems. It specifies the performance of standard measuring instruments and the measurement standards for harmonic currents emitted by equipment.
IEC 61000-4-15
This international standard provides you with relevant standards and requirements for voltage fluctuation flicker technical measurements in various power systems.
EN 50160
It provides you with European standards for power supply voltage and other power quality standards.
IEEE 1159
Provides you with quality monitoring standards and standardized processes for power system testing.
IEEE 519
Provides you with standards for relevant voltage harmonics and current harmonics. It includes voltage, current, frequency, harmonics, transients, and other related parameter data to help you analyze the power quality of various systems and ensure that your power quality meets unified standards.
What Is Power Conditioning-sourced: fujielectric
Power system conditioning is to protect your equipment from external power quality through advanced technology and means. It can improve the power quality of your energy system and improve the efficiency of power utilization.
Not only can it provide you with the establishment and utilization needs of personal power systems and equipment, but it can also provide new and increasingly stringent power quality standards for various public utilities.
The following factors can be used to measure the need to meet power system requirements.
Voltage Levels
Keep your electronic equipment within a specific voltage range. Changes in the voltage level of the equipment can cause equipment failure and various power quality problems.
Unbalanced Voltage
Unbalanced Voltage-sourced: hyteps
Unbalanced voltage can cause various power quality problems. Different voltage amplitudes produce asymmetrical waveforms, causing load imbalance and ultimately connection failure. Unbalanced current can cause equipment to overheat or operate inefficiently, posing a safety hazard to the equipment.
Voltage Sags
Voltage Sags-sourced: ucarecdn
A voltage sag is when the voltage of the equipment system temporarily drops below normal levels for several cycles. This is usually caused by a sudden increase in load, causing the grid voltage to drop.
Voltage Swells
Voltage Swells-sourced: powerquality
A voltage swell is when the voltage of the power system temporarily rises above normal levels for several cycles. This is usually caused by a load change or system failure.
Voltage Interruptions
A voltage interruption is when the equipment shuts down or restarts for a few seconds to a few minutes, causing damage to the equipment or loss of data.
Flicker
Lightning is a momentary change in voltage. It is characterized by a rapid change in voltage amplitude. This condition is usually caused by a sudden change in load, such as the start-up of a large motor or power system equipment, such as an arc furnace, welding machine, or large drive.
Electrical interference
Electrical interference-sourced: medschool
Electrical interference refers to the mixing of noise signals from other electrical systems, power lines, or radio transmissions into the power system. This electrical noise affects the signal attenuation of the power system, thereby interfering with the normal operation of normal equipment.
Inadequate grounding
When power system equipment is not connected to the ground, the stability of the power system cannot be guaranteed, noise and interference cannot be reduced, and the shock caused by static electricity accumulation cannot be prevented, which can easily damage sensitive electronic equipment.
Harmonics
Harmonics-sourced: thedawstudio
Electrical harmonics of high-frequency signals can pollute power equipment and power transmission systems, causing damage to electrical equipment.
Transients
Transients-sourced: majormixing
When the voltage or current of the power system undergoes a sudden and short fluctuation in a short period of time, a voltage transient occurs. This situation may be caused by lightning strikes, switching operations, or power system faults. Such transients generally last from a few microseconds to several seconds.
If your power system is experiencing low power quality, your system may have the following problems:
Equipment downtime
Equipment downtime-sourced: dreamzcmms
Low power quality in the power system will directly lead to equipment failure or equipment downtime, which will increase your operating costs.
Production stoppage
Production stoppage-sourced: lean
When power quality seriously affects the normal operation of your equipment, or even causes equipment damage, it will indirectly cause your production losses.
Increase costs
When your production stops or the equipment operation efficiency becomes low, your production costs increase, making the benefits lower.
Equipment damage
Low power quality will cause voltage changes in the power system, so that your power equipment and other equipment are subjected to different power pressures, causing equipment failures and damage.
The following potential factors can also cause a decrease in system power quality.
Non-linear loads
Non-linear loads-sourced: ytelect
Non-linear loads in power systems can easily cause harmonic distortion, which can affect the efficiency of power quality applications and cause equipment downtime or failure.
The following steps can help you solve power quality problems.
Power Quality Analysis
Power Quality Analysis-sourced: enerdoor
The first step to solving power quality problems is to deeply analyze the power quality of the power system so that the corresponding solutions can be applied to solve the power quality problems. You can measure and evaluate the power quality parameters such as voltage, current, frequency, and harmonics of the power system.
Voltage Regulation
Voltage Regulation-sourced: cyberpowersystems
The first step to solving power quality problems is to regulate the voltage of the power system. You can install some professional voltage regulation equipment, such as voltage regulators, stabilizers, or transformers.
Use power conditioning equipment
Reduce power quality problems by using various surge protectors, uninterruptible power supplies, and harmonic filters.
Use high-quality electrical equipment
High-quality electrical equipment can reduce the occurrence of power quality problems, such as motors, transformers, and inverters.
Improve grounding
Improve grounding-sourced: kritester
Properly grounding the electrical system of the equipment or adjusting the grounding can help eliminate ground loops, reduce noise and interference, etc.
What Is RFI (EMI) / EMC-sourced: est-aegis
EMI, also known as RFI, is a type of interference that affects circuits and refers to electrical noise of any frequency. The noise originates from electromagnetic conduction or electromagnetic radiation emitted by external sources.
EMC refers to the electronic or electrical products that should work as expected in their environment. It generally deals with the noise emission and interference immunity of electronic and electrical products and systems.
Different power quality issues require different solutions. Here are some ways to apply targeted solutions.
Voltage fluctuations
Voltage fluctuations-sourced: sciencedirect
When your power system experiences voltage fluctuations, you can try a voltage stabilizer to automatically adjust the voltage. It not only compensates for voltage changes and keeps the voltage constant, but also automatically adjusts the voltage.
Automatic switching transformers
Automatic switching transformers-sourced: eaton
By automatically switching transformers, you can adjust the overall voltage level according to changes in your own power grid.
Power outages
Power outages-sourced: myslidell
You can use UPS and uninterruptible power supplies. This power supply can provide power to your power system in a short period of time and ensure that the equipment can be shut down correctly.
Voltage sags
Voltage sags-sourced: dam-assets
To deal with voltage sags, you can try a sag compensator. That is, the compensator can continue to provide power when the voltage drops for 1 second.
Micro-interruption compensators
Micro-interruption compensators can ensure the normal supply of power in the case of extremely short current interruptions.
Emergency generators
Emergency generators-sourced: odysseypower
Emergency generators can provide power to your energy devices in the event of a long power outage.
Battery storage systems
Battery storage systems-sourced: energytoolbase
This storage system can provide you with a stable power source when the power is interrupted.
Harmonics
The best solution to deal with harmonics is to use active harmonic filters or passive harmonic filters. It can not only detect and compensate for harmonics in the power system in real time, but also attenuate harmonics.
Flicker
When flicker occurs in the power system, you can use a static reactive power compensator to improve the power problem. It can quickly adjust the voltage, reduce flicker, or eliminate rapid voltage fluctuations.
Power factor problem
Power factor problem-sourced: powerquality
When facing power factor problems, you can compensate for reactive power through capacitor banks or static reactive power compensators. At the same time, correct the power factor.
Electromagnetic and transient interference
Electromagnetic and transient interference-sourced: geeksforgeeks
Protect equipment from sudden voltage spikes and reduce electromagnetic interference by using surge protectors and electromagnetic RF filters.
Properly ground the line
Properly grounding the shielded line can help reduce electromagnetic noise.
How To Address Power Quality Issues-sourced: mdpi
Power quality issues require long-term and continuous attention and adjustments to maintain a reliable power supply and improve power application efficiency.
You can adopt a traditional PQM system. The equipment is measured and evaluated for a 10-minute average value over 7 days.
Learning the terms related to power systems can help you better understand and know your power system. These terms include:
What Are The Power Terms For Power System-sourced: googleusercontent
| Sine wave | Sine wave generally refers to the normal waveform of the voltage generated by the generator. |
| Peak value | That is, the maximum amplitude of the waveform. |
| Average value | The average value generally refers to the average value of the sum of the instantaneous peak values of the waveform. It is usually calculated by multiplying the peak value by 0.637 for a sine wave. |
| Root mean square value | It refers to the effective value of the waveform or the total amount of heat and work. It is calculated by multiplying the peak value by 0.707 for a sine wave. |
| Crest factor | That is, the ratio of the peak value of the waveform to the root mean square value, the peak or maximum current it requires. |
| Impedance | That is, the resistance in the AC current. |
| Linear load | It mainly refers to the load whose power consumption is proportional to the voltage applied to the system. |
| Non-linear load | The load whose power consumption is independent of the voltage applied to the system. |
| Harmonics | Multiples of the line frequency. |
| Harmonic distortion | System distortion caused by currents above the line frequency. |
As modern power systems are moving towards sustainability and complexity, some power quality issues are also facing challenges. These include:
Power quality of carbon-free systems
Power quality of carbon-free systems-sourced: weforum
The current power grid energy system is moving towards a carbon-free power system. As centralized power plants turn to decentralized energy sources such as solar panels, electric vehicles, and wind farms. Different voltage levels are also increasingly changing with the flow of energy, and are facing the risk of overload, which means that the power grid needs to be operated, adjusted, and reinforced.
Load pressure
With the power pollution caused by devices such as LED lights, computers, medical equipment, and electric vehicle chargers, the load pressure and sustainability of the power system are being challenged.
What Are The Market Trends For Power Quality-sourced: media
Modern grid systems and power quality are shifting towards carbon-free generation. That is, large-scale centralized and distributed power sources from renewable energy are gradually replacing traditional thermal power plants. This shift will lead to the integration of a large number of power electronic devices, the use of various voltage levels, power cables, and an increase in the production of fluctuating energy.
To improve the consistency, reliability, and stability of power quality, you can take measures to maintain good power quality. This will not only avoid equipment damage or failure, system downtime, and data loss, but also ensure the sustainable, safe, and efficient use of power systems and equipment. Learn more here.
