- How does the Smart Voltage Energy Saving (ESU) Unit Work?
- Voltage Optimisation
- Product Reliability
- Energy Savings – Advanced
The general focus of energy savings to date has been on technologies, systems and human behavior downstream of the electrical switch-room or Main Distribution Board (MDB). As a result, conservation measures have focused on BMS, EnMS, energy efficient lighting, LEDs, slow-starters and VSDs. There has been little or almost no focus on the quality of electricity that enters a building and the effects on every appliance and piece of machinery within it.
The Smart Voltage ESU aims to change this by refining and optimizing the raw power quality it receives from the distributor – tailoring voltage to a level. This enables electrical equipment to run more efficiently and create significant electricity savings. The optimized voltage also create capacity savings for the distributor and significant carbon emission savings.
The Smart Voltage ESU does this by improving the following key areas of power quality:
- Voltage Optimization and Conservation: Reducing and optimizing the voltage to a level that is suitable for each individual business premise. Given that nearly 90% of all business premises operate at the upper end of the prescribe range, we aimed to see energy users and businesses in general operate at mid-point of the prescribe voltage range of MS IEC60038. The improve voltage will reduce electricity demand and energy consumption.
- Power Factor Correction: The Smart Voltage ESU is not a dedicated power factor correction unit, however it typically improves power factor in the order of 0.01 to 0.08. This occurs by combining the action of Coils A and B (within The Smart Voltage ESU) to compensate with reactive energy as required when phase current tends to lag excessively behind voltage. This is achieved via the unique combination of physical location and electrical connection of Coil A in series and Coil B in parallel with the load. Coil A provides energy to the load for the most part. However, as a fundamental of alternating current principles there are ‘gaps’ in Coil A’s supply. Coil B compensates for these ‘gaps’ by way of the unique interconnection of Coils A and B to maintain or improve Power Factor.
- Harmonics Filtering: Whilst ESU is not a dedicated harmonics filter, it is able to reduce harmonic distortions (both voltage and current harmonics) as a result of the built-in tertiary winding and thus helps address the problems associated with high harmonic levels. As losses due to unwanted harmonics increases with increases in frequency, The Smart Voltage ESU gives notable energy reduction at lower frequencies with increasing reductions as frequency increases.
- Phase Balancing: Within The Smart Voltage ESU, as each phase is star connected to each other and due to the manner of interconnection between the two coils, a level of voltage balance between each phase is provided at the unit’s output. The effect is a more suitable supply to the connected load, providing increased efficiency in the operation of loads – in particular rotating loads (e.g. 3 phase synchronous motors).
The Smart Voltage ESU uses a high efficiency transformer core made of amorphous alloy (Fe-B-Si). The magnetic core is constructed not in the regular rectangular shape of conventional inductive devices but in a similar shape to that of a magnetic field. This design provides an extremely efficient path for the magnetic fields within the cores to circulate with very little energy loss with an efficiency of >99.8%. The core construction is made of long strips which has the effect of maximizing magnetic field strength while minimizing losses in energy due to eddy current. Each coil is constructed with high grade copper to minimize resistance and reduce impedance, providing more than 2x the magnetic circuit conductance of standard materials. The coils are insulated with grade “H” insulating materials for galvanic isolation and longer operating longevity.
The second important technology applied to The Smart Voltage ESU is the incorporation of the Eniscope Real-time Energy Monitoring System. The Eniscope delivers 3-Phase voltage reference, multi-circuit monitoring with ethernet connectivity, allowing it to connect over local network or the internet enabling persons in charge (building managers/energy managers) to measure and monitor real-time key energy performance indicators and identify, control and perform energy savings action.
How is it possible to optimise voltage on a site-specific basis?
The statutory supply range for electricity in Malaysia is 216V to 253V i.e. 230V -6% to +10% (MS IEC60038:2006). Due to the fact that transmission losses occur through the electricity grid, the majority of premises receive voltage at the high end of this range. This is to ensure that the premises located at the extremities of the grid receive voltage above the minimum allowable level.
However most electrical equipment used in Malaysia (and globally) is designed to function optimally at 220-230V and will even operate effectively down to 200V. When motors and equipment operate at voltage levels higher than what they are designed for (i.e. greater than 220V) there is a degradation of the equipment and energy is lost through heat (joule heating), vibration etc. As the iron losses are proportional to the square of the voltage increase, this over-voltage leads to significantly higher electricity consumption due to the energy that is wasted.
From the extensive data logging that the Company has performed, we estimate that approximately 90% of sites in Malaysia are operating at an over-voltage level (with an overall average of approximately 240V) and could therefore significantly benefit from installing The Smart Voltage ESU to optimise their voltage.
The Smart Voltage ESU’s amorphous alloy transformer technology optimises voltage, enabling motors and equipment on-site to operate within their optimal (and design specified) voltage range of between 220-230 Volts, while also delivering energy savings to the end user.With >99.8% internal efficiency, The Smart Voltage ESU is able to reduce voltage without increasing current and hence achieves a net reduction in power usage for the same net output of motors and equipment.
The Smart Voltage ESU with its built-in real-time power monitoring enables users, building managers or energy managers to step-down incoming voltage received from the utility provider to the nominal level and works on improving other key areas of electricity supply such as Voltage phase balancing, harmonics filtering and power factor corrections – all from a single box installed in the electrical room. No other energy efficiency or energy savings system available today allows for this.
Furthermore, we are able to identify, implement and verify a wide range of strategies and technologies that will enhance savings and control of energy management from multiple sources and delivers critical information, be it kWh, cost, voltage or carbon. The data is made available across networks, to be viewed on any computer, or across a range of portable devices, from anywhere in the world.
Why do electricity suppliers provide high voltage levels?
It is most common for network operators to set voltages towards the higher end of a statutory band for a number of reasons:
- Voltage drop – setting a course tapping on substations ensures that supply quality is maintained across all customers on the grid i.e. the approximate 10% of premises that are already receiving voltage levels at the lower end of the statutory band would have their power supply seriously compromised by broad scale voltage reduction by the electricity suppliers.
- Transmission losses – high voltage transmission produces lower losses on the network’s grid – thus saving the network operator money and improves the working life of their network assets.
- Reducing the voltage would result in an immediate loss of income for the network operator and retailer, as consumers would be paying less for their supply.
- It would take a colossal level of investment for the electricity suppliers to alter the electrical infrastructure to lower voltage universally while still ensuring adequate supply to all end-users.
Accordingly, supply authorities are not in a practical position to be able to step down voltages universally. Site-specific voltage optimization is the best method to refine electricity supply and The Smart Voltage ESU technology is able to do this in a manner that achieves significant electricity savings and power quality improvements for the end user.
What voltage optimisation levels can the Energy Saving Unit be set at?
The voltage optimization of The Smart Voltage ESU can be set at tappings of 6%, 8% or 10%.
In Malaysia, the statutory minimum voltage is 216V, hence the voltage optimization cannot be set to reduce the voltage below this level.
Assuming a typical voltage of approximately 240V, an 8% tapping will reduce the voltage to approximately 221V. If the incoming voltage is higher than this, it is often possible to optimise the voltage by 10%, providing larger energy savings.
The voltage at a site will generally fluctuate substantially over a 24-hour period. By measuring the voltage at 1-minute intervals over a 7-day period, we are able to get a very thorough understanding of the electricity supply quality delivered to a site, enabling us to set the appropriate voltage tapping level with regard to the statutory band.
Is the output voltage in direct proportion to the supply voltage?
The output voltage level is directly proportional to the supply voltage. From the results of our power quality analysis we are able to determine the appropriate voltage optimization for a site – either 6,8, or 10%.
Could I tap down my transformer to generate energy savings?
The purpose of the supply authority transformer tap-downs is to provide voltage within the Malaysia statutory range, rather than provide energy savings for the end-user.
When a traditional step-down transformer with high internal losses is used to tap down Voltage (V), the system losses are maintained and the Current (I) increases with the decrease in Voltage and hence there is only a small net reduction in energy used. Hence, the savings achieved by tapping down the voltage on a conventional transformer will only be very minor compared to those achieved from The Smart Voltage ESU installation.
The Smart Voltage ESU’s ability to optimize voltage with greater than 99.8% internal efficiency (in combination with its other energy saving principles – improving power factor, 3-phase voltage balancing and reducing harmonic distortions), without drawing more current, is what makes the technology unique and enables it to provide electricity and carbon emission savings.
In addition to the energy savings generated by The Smart Voltage ESU, its installation benefits a site’s overall power quality and helps protect its electrical infrastructure. Hence, the savings and benefits from The Smart Voltage ESU installation far exceed those offered by a traditional transformer tap.
What are the differences between The Smart Voltage ESU and traditional autotransformers?
There are fundamental differences between the two devices.
|The Smart Voltage ESU||Traditional Autotransformers|
|Designed to save energy and to improve the quality of power supplied to a site||Designed to control voltage|
|Operates with exceptional efficiency (i.e. greater than 99.8%)||High internal losses (energy dissipated via heat and vibration) results in efficiency of around 85-90% varying according to loading conditions.|
|No moving parts or electronics enables maintenance free operations, with an expected lifespan of 30+ years.||Inefficiencies and wear from moving parts increases maintenance requirements and results in short life spans.|
|In addition to optimising supply voltage, also improves power factor, 3-phase voltage balance and reduces harmful harmonics.||Negatively affected by Harmonic distortions.|
|Does not produce noise||Produces noise|
|Pin ≅ Pout||Pin ≠ Pout|
|Compact size||Large size|
How is it possible to optimise voltage on a site-specific basis?
No. It is a ‘set and forget’ installation.
All we recommend is an occasional dust removal and thermal imaging test that would be applied to any other high current electrical device or switchboard.
Why do electricity suppliers provide high voltage levels?
The Smart Voltage ESU has the ability to withstand high over current conditions at a high rate of change, e.g. high-power surge currents. The Smart Voltage ESU can withstand 2 times its maximum rated current (I) for 2 minutes and withstand shock current 105 times the maximum rated current (I) for 300msecs. The simple construction of the iron core and winding as well as the very high quality ‘H’ grade material of construction (offering high temperature withstand limit) enables The Smart Voltage ESU to provide an extremely robust, stable supply under most normal and abnormal conditions of operation.
On what load types can The Smart Voltage ESU generate savings?
It can generate savings across a wide variety of load types, including;
- mechanical services i.e. HVAC (heating, ventilation, air-conditioning)
- 3-phase motors
- general power
- HID lighting
- fluorescent lighting
- incandescent/ backlash halogen lighting
This means that viable Ark solutions can be tailored for nearly any industry sector.
What happens to electric motors when they are supplied with high voltage levels?
Motors are particularly susceptible to over-voltage. While it depends where they are manufactured, the majority of 3-phase motors in Australia are designed to operate optimally at 380-390V. The average supply voltage in Australia is significantly higher than this (approximately 415V). Some of the problems this excess voltage creates for 3-phase motors include;
- Internal energy losses (iron and copper losses in the form of heat)
- The iron core becomes saturated as the motor draws excess current. The core is magentised beyond its optimal and designed rated capacity and the iron loss is proportional to the square of the voltage increase.
- Additional internal losses as a result of the reversing magnetic field passing through the iron core.
- Extra strain upon the motor (heat, vibration etc.) reduces its life span and increases maintenance requirements.
How does The Smart Voltage ESU create savings with electric motors?
As we know, Power (kW) is equal to the Voltage (V) multiplied by the Current (i), kW = V x I.
Power into a 3-phase motor (kW in) is equal to the power out (kW out) plus system losses (heat and vibration). A motor running on higher voltage than required will have increased copper and iron losses for a similar power output, as well as poorer power factor. Hence the electricity consumed (kW in) significantly increases with an increase in voltage beyond a motor’s optimum capacity.
With a Smart Voltage ESU installed, the internal losses and the stress on motors is significantly reduced.
A Smart Voltage ESU installation enables motors and equipment on-site to operate within their optimal (and design specified) voltage range, while also improving power factor, 3-phase voltage balancing and reducing harmonic distortions. The net effect is that motors operate with greater efficiency. There is a significant reduction in internal losses and hence a net reduction in power usage for the same motor output. There is no effect on the speed of the motor as this is determined by the number of poles on the motor and the frequency of the electricity supply. By providing voltage within the motors design specified voltage range, there is no reduction in torque.
As a result, The Smart Voltage ESU provides very good savings on loads with 3-phase motors. Hence, mechanical services loads, such as air-conditioning, ventilation, heating, refrigeration and general plant and machinery provide attractive ROI’s when tailoring Smart Voltage ESU solution for a site.
What about Ohms Law?
Since Power = Current x Voltage (P = I x V), the common electrical paradigm and traditional teaching is that if you reduce voltage, the current will increase proportionally.
In order for the current and voltage to be inversely proportional, this interpretation of the formula assumes that electrical loads have constant power i.e. regardless of changes in voltage and current, a 2kW motor will always use 2kW. In real life, this is not the case and the formula simply means that the power being drawn is the product of voltage and current.
Power into a 3-phase motor (kW in) is equal to the power out (kW out) plus system losses (heat and vibration). In a theoretical sense, there are no system losses. However, in real-world applications, we know that this is not the case. Anyone who has observed the heat, vibration and noise of a motor is aware that this is a dissipation of energy that is not being used to create output from the motor. The introduction of these system losses as a result of poor electricity quality, outside of the controlled environment of Ohms Law theory, is what changes the practical interpretation of the law in this instance.
The nameplate power of machinery will be delivered at any voltage within the statutory range of 216-253V in Malaysia. However, when a motor receives voltage above its optimum and design specified level, additional energy is used for no improvement in performance. It will continue to deliver its rated output, but will use more energy to do so as the core is driven into saturation and iron and copper losses increase. Energy is dissipated in the form of heat and vibration and more energy is consumed as a result.
By optimising the voltage to the most efficient operating point for motors and equipment (and also improving the power factor, improving 3-phase voltage balancing and reducing harmonic distortions) The Ark significantly reduces the losses that are created by poor electricity quality, and consequently reduces the energy consumed by the motor while delivering the same output.
Further, it is known that Voltage (V) = Current (I) x Resistance (R).
As P = I x V (and I = V/R), by substitution P = V2/R.
If we assume that the resistance is constant, it follows within Ohms Law theory that with a reduction in voltage, the power will reduce as the square of the voltage. This is what actually happens with most electrical equipment in a practical situation. Accordingly, reducing the voltage from the average supply level in Australia of 240V, by 8%, on a 20Ω load, will result in a reduction in the power from 2.880 kW to 2.42 kW. This application of Ohm’s Law theory provides for a 16% saving in energy.
This level of savings from The Smart Voltage ESU on 3-phase motors is very clearly demonstrated in practical applications.
Will my electric motors be affected in any adverse way by The Smart Voltage ESU?
No. Independent tests have been carried out by the University of Newcastle in response to initial electrical engineering concerns that reducing the voltage delivered to electric motors will cause the motors to heat up. The results of this test and the practical application of The Smart Voltage ESU in client's premises over many years clearly proves that it does not have this effect.
How does The Smart Voltage ESU compare to VSD's or VFD's on motors?
An installation The Smart Voltage ESU on a load with AC Motors will deliver comparable energy savings to a typical VSD (Variable Speed Drive) or VFD (Variable Frequency Drive) installation.
If a VSD or VFD is already installed, an Ark installation will still generate savings, however they will be less than would be achieved without the VSD or VFD installed.
Due to The Ark’s ability to improve the quality of power supplied to the load (by optimising the voltage and improving the power factor, 3-phase voltage balancing and harmonics), the lifespan of any VSD’s or VFD’s already installed will be extended as a result of an Ark installation – particularly due to the susceptibility of VSD’s and VFD’s to the stresses associated with over-voltage.
Additionally, VSD’s and VFD’s are renown for the harmonic distortions that they create. Due to the harmful effects of harmonic distortions on sensitive equipment, The Ark’s ability to reduce harmonics will help mitigate the damaging effects of VSD’s and VFD’s.
What are the consequences of harmonic distortions?
Harmonics can be likened to pollution within your power supply. The consequences of excessive harmonic levels include overheating of distribution boards, de-rating of circuit breakers, degradation of power factor correction equipment, overheating in cables (increasing the risk of damage to cables and electrical infrastructure and potentially the risk of fire), de-rating the output of generators, inefficiencies in the operation of electrical motors and wasted energy consumption.
Sources of harmonic distortions can be electronic loads, electronic ballast fluorescent lights, computers, UPS units, Variable Speed Drives (VSD’s), Variable Frequency Drives (VFD’s) etc.
Due to the increasing proportion of electronic devices and ‘non-linear’ loads within premises, the occurrence of the problems resulting from harmonic distortions is also increasing.
What effect does The Smart Voltage ESU have on Harmonics?
The Smart Voltage ESU does not create harmonics.
Further, whilst The Smart Voltage ESU is not a dedicated harmonics filter, it is able to reduce harmonic distortions (both voltage and current harmonics) as a result of the built-in tertiary winding and thus helps address the problems associated with high harmonic levels.
Losses due to unwanted harmonics increases with increases in frequency. The Smart Voltage ESU gives notable energy reduction at lower frequencies with increasing reductions as frequency increases.
What are the consequences of 3-phase voltage imbalance on motors?
The effect of 3-phase voltage imbalance is somewhat analogous to a spinning wheel. If the wheel is not completely balanced, the force required to maintain the spinning motion is higher than for a balanced wheel. Hence, in practical terms, 3-phase voltage imbalance can result in significant energy waste and heating of motors and wiring. Maintenance requirements also increase as motors run less efficiently.
What effect does The Smart Voltage ESU have on 3-phase voltage imbalance?
The Smart Voltage ESU is able to improve the voltage balance between the 3-phases.
Within the Smart Voltage ESU, as each phase is star connected to each other and due to the manner of interconnection between the two coils, a level of voltage balance between each phase is provided at the unit’s output. The effect is a more suitable supply to the connected load, providing increased efficiency in the operation of loads – in particular rotating loads (e.g. 3 phase synchronous motors).
What are the consequences of poor power factor?
Power Factor is essentially a measure of how effective electrical power is being used by a system. It is represented by a numerical value between 0 and 1, equal to the ratio of reactive power to active power. The higher the value, the more efficient the system.
A system with poor power factor requires the energy retailers to supply more power in order for end-use equipment and appliances to operate. The requirement of this additional power can result in excessive heating of equipment and electrical infrastructure, additional maintenance costs and the potential for fires in extreme situations.
In regions where customers are charged on the basis of kilovolt amps (kVA), a financial penalty is effectively charged for poor power factor.
What effect does The Smart Voltage ESU have on power factor?
The Smart Voltage ESU is not a dedicated power factor correction unit, however it typically improves power factor in the order of 0.01 to 0.08. This occurs by combining the action of Coils A and B (within The Ark) to compensate with reactive energy as required when phase current tends to lag excessively behind voltage. This is achieved via the unique combination of physical location and electrical connection of Coil A in series and Coil B in parallel with the load. Coil A provides energy to the load for the most part. However, as a fundamental of alternating current principles there are ‘gaps’ in Coil A’s supply. Coil B compensates for these ‘gaps’ by way of the unique interconnection of Coils A and B to maintain or improve Power Factor.
What effect does The Smart Voltage ESU have on different lighting types?
The Smart Voltage ESU is able to generate high levels of savings on lighting loads, particularly the following types;
- HID lighting
- Standard fluorescent lighting
- Incandescent lighting
- Halogen lighting
Lighting is typically a substantial and consistent user of electricity, so significant savings can be achieved by improving the efficiency of lighting loads.
Optimising the voltage to the correct level will improve the efficiency of all types of lighting, including those with resistive or magnetic ballasts. If other energy efficient lighting devices have already been installed, The Smart Voltage ESU can generally still create further savings, however the savings will be less than without the other energy efficient device.
As well as creating energy savings, optimising the voltage provides significant improvements in the lifespan of lights.
Incandescent lighting is particularly susceptible to high voltage levels and a 5% increase in voltage decreases the life of lamps by up to 47%. For fluorescent lamps, an increase in voltage of 10% decreases lamp life by up to 15%. Minimising lamp change frequency by optimising voltage creates significant cost savings in labour and replacement consumables.
How does this technology compare to other energy efficiency measures for lighting?
Fixed dimming units can only be used on some lighting loads. This means that energy saving can only be achieved on the portion of your total power bill relating to this suitable lighting, which in most cases represents only 20-25% of your electricity consumption. Fixed dimmers on lighting generally run at full voltage for 5-10 minutes on start up, so lights that are only on for short periods of time or are used intermittingly will see reduced savings. The Ark works anytime that lights are switched on.
Some lighting control systems mechanically drop the voltage a pre-set amount. This type of lighting control is not compatible with The Smart Voltage ESU, as the voltage reduction from the action of both devices would reduce the voltage too low for the effective operation of the lighting.
Other energy saving measures on lighting use electronic controllers or electronic ballasts. Because these devices are responsible for generating high levels of harmonic distortions, The Smart Voltage ESU can improve the efficiency of these loads further by helping filter the harmonics and thus helping provide protection for sensitive equipment.
Optimising voltage with The Smart Voltage ESU can reduce the need for the investment in energy efficient lighting devices, as lighting loads are made significantly more efficient by the operation of The Smart Voltage ESU . Savings can be provided with one product across the entire premise, encompassing not only the whole range of lighting, but also general power and mechanical services loads.
Does The Smart Voltage ESU work for resistive devices?
Typically, a resistive device that is specifically designed to produce constant power (including some lighting and ovens/ electrical kiln heating) will result in a lower level of savings. For this type of equipment, although the voltage supply is reduced, the device is rated so that it will draw more current to provide constant power.
If we are placing The Smart Voltage ESU on a general light and power load, it will usually contain a mixture of electrical load types, and savings are aggregated across all the equipment. The effect of any resistive devices upon the energy savings is factored into your projected financial payback during the site assessment stage.