Advanced Energy Dynamics, LLC
AED improves facility efficiency while reducing electric costs up to 25%.
We will correct your electrical efficiencies within your facility immediately by improving motor performance. No disruption or change to your daily operations is required!
By allowing Advanced Energy Dynamics to assist you in solving these power quality problems you will realize the following cost-saving benefits:
- 1. Increased reliability (less downtime)
- 2. Decreased maintenance and replacement costs for machinery
- 3. Energy Savings (KW, KWH, and reduced power factor penalties)
- 4. Improved customer satisfaction
Intermittent Supply Failures
Voltage irregularities are one of the greatest power quality issues facing industry today. In fact, about 95% of the problems revealed in electrical networks stem from voltage problems.
Over/Under-voltage:
Technically speaking, an over/under-voltage condition is reached when voltage exceeds/lags the nominal expected supply voltage by 10% for more than 1 minute. These conditions result in voltage that falls outside the acceptable power envelope as defined by the Computer and Business Equipment Manufacturers' Association (CBEMA).
Short-Term Voltage Fluctuations:
Short duration voltage events can also occur such as transients, sags or dips and swells. Although shorter in duration (by definition they are all shorter than 1 minute), these events can reach a magnitude that falls outside the acceptable power envelope. When this happens, high voltage events can lead to insulation breakdown, overvoltage tripping and over excitation. The low voltage events may cause loads to drop out altogether. Both conditions result in customer complaints due to system unreliability and often damages equipment impacting on system integrity.
Voltage Imbalance:
Voltage imbalance is most often seen as a result of single-phase motors installed on a three-phase circuit. Voltage imbalance that exceeds 2% is detrimental to reliable long-term 3-phase motor operation, and the National Electrical Manufacturers Association (NEMA) says a motor should not be operated with a voltage imbalance at or above 5%.
Voltage imbalance generates unwanted heat in motors. This, in turn, results in wasted energy, insulation breakdown and ultimate motor failure, and improper and inefficient motor operation. A 5% voltage imbalance would result in a 50% increase in temperature.
Intermittent Supply Failures:
Short duration intermittent supply failures can last anywhere from 0.5 cycles up to 1 minute and can be caused by a number of occurrences such as supply system faults (caused by lightning or other natural phenomena), equipment failures, or malfunctions in control equipment. These intermittent supply failures can be very costly to industry and can cause loss of microprocessor memory, improper motor and other equipment operation or failures, and loss of control equipment.
Imbalanced currents:
Imbalanced currents often arise when single-phase loads are employed unevenly on a 3-phase distribution system. When the imbalance approaches 10%, problems such as negative voltage sequence, circulating currents, increased current in neutral conductor, increased Neutral-to-Ground voltage, overheating of motors, insulation breakdown and subsequent motor failures, reduced motor efficiency, increased maintenance of equipment and machinery, wasted energy and higher electric bills. All of these cause a loss to investments and operating capital.
Harmonics:
Harmonics are a distortion of the supplied frequency (60 Hz). Harmonic distortion of current occurs when the 60-cycle supply voltage is applied to a non-linear load (ex. electronic ballast, PLC, adjustable-speed drive, arc furnace, any ac/dc converter). More often than not, the sources of the harmonic currents in a distribution system are the loads in operation within that facility, and more interestingly, these loads are frequently the most sensitive to distortion in the current and/or voltage. Harmonics cause a distortion of the current waveform, which indirectly causes a distortion of the supply voltage.
In general, harmonics present on a distribution system can cause overeating of transformers & rotating equipment, increased hysteresis losses, decreased kVA capacity, neutral overloading, unacceptable neutral-to-ground voltages, distorted voltage and current waveforms, breakers and fuses tripping, interference on phone and communications systems, unreliable operation of electronic equipment, erroneous register of electric meters, wasted energy / higher electric bills - kW & kWh, wasted capacity - inefficient distribution of power and increased maintenance of equipment and machinery.
Power Factor:
Power Factor is the ratio of Real Power (kW) to Apparent Power (kVA). In a purely resistive circuit, all of the current delivered to the load is converted to real work (kW). Therefore, the kW=kVA, and the Power Factor = 1 (unity). However, many loads in industry today are inductive. This inductance causes the current to lag behind the voltage, and the reactive and harmonic currents drawn are used to create the magnetic field needed to operate these machines. Thus, power is lost in the magnetic field and kW < kVA, and the Power Factor < 1. Low Power Factor causes increased line losses - I2R. ; wasted distribution / transformer capacity (kVA), wasted system capacity (kVA), reduced system efficiency (kW), increased max. demand (kVA), & related charges, possible poor power factor penalty charges, increased maintenance of equipment and machinery, wasted energy / higher electric bills, and wasted investment and operating capital.
Overloaded Transformers (loss of kVA capacity):
Overloaded transformers are found in industry as a result of a combination of factors. Often times expansion without adequate capacity planning can lead to overloaded transformers. This combined with the poor power factor and high harmonic currents generated by inductive loads, can cause a transformer to become heavily loaded. Whatever the cause, an overloaded transformer presents an obstacle to future plant expansion and heavily overloaded transformers can overheat and pose a potential fire hazard.
Lightning:
Lightning can cause serious problems and extensive damage in an electrical distribution system. As mentioned previously, lightning strikes can cause intermittent supply failures. In fact, EPRI has estimated that lightning causes approximately 30% of all power outages. In addition, lightning can generate dangerously high-magnitude transient overvoltages that flow into a distribution system.
Brownouts:
Although no formal definition exists in the power quality literature, the term "brownout is generally used to describe a long-duration undervoltage condition. These long-duration undervoltage conditions can cause equipment shutdowns, loss of microprocessor memory, reduced motor torque, increased motor stalling, overheating of motors (insulation breakdown), tripping of protective devices, speed variation in ASDs.