Static Var Compensation (SVC) Static Var Compensators (SVC) are devices that can quickly and reliably control line voltages. An SVC will typically regulate and control the voltage to the required set point under normal steady state and contingency conditions and thereby provide dynamic, fast response reactive power following system contingencies (e.g. network short circuits, line and generator disconnections). In addition, an SVC can also increase transfer capability, reduce losses, mitigate active power oscillations and prevent over voltages at loss of load. The SVC is customized to fit each customer with their specific needs. The SVC consists of a number of fixed or switched branches, of which at least one branch includes thyristors, and the combination of branches can be varied a lot depending on requirements. An SVC typically includes a combination of at least two of the given items below (e.g. TCR/FC or TCR/TSC/FC): ◆ Thyristor controlled reactor (TCR) ◆ Thyristor switched capacitor (TSC) ◆ Harmonic filter (FC) ◆ Mechanically switched capacitor bank (MSC) or reactor bank (MSR) MV SVC contactor switched APFC capacitor banks MV SVC Contactor switched SVC capacitor banks Most common topologies for SVCs are: TCR/FC or TCR/TSC/FC. The main advantage for using a topology with TSC branch(es) is to reduce the losses (by reducing the filter size). Mechanically switched banks can be included both on HV and LV side of SVC transformer to increase the total reactive power support outside the dynamic range.  SVC control system can be utilized for controlling new or existing external shunt banks. ZDDQ L.V SVC Contactor switched capacitor banks ZDDQ L.V SVC TSC capacitor banks Applications ◆ SVC Solutions for Utilities ◆ SVC Solutions for Metal Industries ◆ SVC Solutions for Mining Industries ◆ SVC Solutions for Chemical Industries ◆ SVC Solutions for Oil and Gas Industries ◆ SVC Solutions for Heavy Industries ◆ SVC Solutions for Automotive Industries

What is SATACOM? STATCOM or Static Synchronous Compensator is a power electronic device using force commutated devices like IGBT, GTO etc. to control the reactive power flow through a power network and thereby increasing the stability of power network. STATCOM is a shunt device i.e. it is connected in shunt with the line. A Static Synchronous Compensator (STATCOM) is also known as a Static Synchronous Condenser (STATCON). It is a member of the Flexible AC Transmission System (FACTS) family of devices. The terms Synchronous in STATCOM mean that it can either absorb or generate reactive power in synchronization with the demand to stabilize the voltage of the power network. Working Principle of STATCOM: To understand the working principle of STATCOM, we will first have a look at the reactive power transfer equation. Let us consider two sources V1 and V2 are connected through an impedance Z = Ra + jX as shown in figure below. In the above reactive power flow equation, angle δ is the angle between V1 and V2. Thus if we maintain angle δ = 0 then Reactive power flow will become Q = (V2/X)[V1-V2] and active power flow will become P = V1V2Sinδ / X =0 To summarize, we can say that if the angle between V1 and V2 is zero, the flow of active power becomes zero and the flow of reactive power depends on (V1 – V2). Thus for flow of reactive power there are two possibilities. 1) If the magnitude of V1 is more than V2, then reactive power will flow from source V1 to V2. 2) If the magnitude of V2 is more than V1, reactive power will flow from source V2 to V1. This principle is used in STATCOM for reactive power control. Now we will discuss about the design of STATCOM for better correlation of working principle and design. Design of STATCOM: STATCOM has the following components: 1) A Voltage Source Converter, VSC The voltage-source converter is used to convert the DC input voltage to an AC output voltage. Two of the common VSC types are as below. a) Square-wave Inverters using Gate Turn-Off Thyristors: In this type of VSC, output AC voltage is controlled by changing the DC capacitor input voltage, as the fundamental component of the converter output voltage is proportional to the DC voltage. b) PWM Inverters using Insulated Gate Bipolar Transistors (IGBT): It uses Pulse Width Modulation (PWM) technique to create a sinusoidal waveform from a DC voltage source with a typical chopping frequency of a few kHz. In contrast to the GTO-based type, the IGBT-based VSC utilizes a fixed DC voltage and varies its output AC voltage by changing the modulation index of the PWM modulator. 2) DC Capacitor DC Capacitor is used to supply constant DC voltage to the voltage source converter, VSC. 3) Inductive Reactance A Transformer is connected between the output of VSC and Power System. Transformer basically acts as a coupling medium. In addition, Tranformer neutralize harmonics contained in the square waves produced by VSC. 4) Harmonic Filter Harmonic Filter attenuates the harmonics a...

Thyristor Switched Capacitors(TSC) TSC is a well established technology that is primarily used to reduce transfer reactances, most notably in bulk transmission corridors. The result is a significant increase in the transient and voltage stability in transmission systems. Thyristor Switched Capacitors enables rapid dynamic modulation of the inserted reactance. At interconnection points between transmission grids, this modulation will provide strong damping torque on inter-area electromechanical oscillations. As a consequence, a TSC rated at around 100 Mvar makes it possible to interconnect grids having generating capacity in the many thousands of megawatts. Often the TSC is combined with fixed series compensation to increase transient stability in the most cost effective way. The TSC concept also enables inherent immunity against subsynchronous resonance (SSR), and thus allows for extended use of series capacitors in specific transmission grids comprising thermal generation. The immunity to SSR is a result of the ABB patented SVR control strategy. TSC Principle There are two main principles supporting TSC technology. First, the TSC provides electromechanical damping between large electrical systems by modulating the reactance of one or more specific interconnecting power lines. In other words, the TSC will provide a variable capacitive reactance. Second, the Thyristor Switched Capacitors/TSC will change its apparent impedance (as seen by the line current) for subsynchronous frequencies in such a way that a potential subsynchronous resonance is avoided. The TSC achieves both objectives by using control algorithms that work concurrently. The controls will function on the thyristor circuit (this in parallel to the main capacitor bank) such that controlled charges are added to the main capacitor, making it a variable capacitor at fundamental frequency but a "virtual inductor" at subsynchronous frequencies. TSC technology From a principal technology point of view, the TSC resembles the conventional series capacitor. The power equipment is located on an isolated steel platform, including the thyristor valve used to control the inductor in parallel with the capacitor bank. The inductor is placed on support insulators outside the platform. Control and protection systems are located on ground potential, together with other auxiliary systems. ZDDQ TSC Products TSC Capacitor banks

Introduction: Based on DSP control technology and Instantaneous power control theory, Wanlida thyristor switched capacitor banks (TSC/TSF) with high-speed switching capability are designed to support the supply voltage of distribution systems and to correct the power factor and eliminate the harmonic current of connected loads. Thyristor zero-crossing switching switches are resistant to mechanical wear, operate without noise, and are capable of practically transient-free switching, so it is more safety than contactor switched capacitor banks. Functions: 1.Improve power factor 2.Stabilize busbar voltage and suppress subsynchronous resonance 3.Eliminate harmonic current 4.Decrease grid loss 5.Optimize reactive power I6.ncrease transformer loading capacity Principles: Thyristor switched capacitor banks is the compensating device based on switching operation of capacitor banks by thyristor. TSC mainly consists of control system, thyristor, capacitors and reactors. Capacitor banks are divided into multiple units to realize step control. TSC is able to implement step regulating in reactive power, accuracy of regulating depends on numbers of multiple unit. Thyristor switched capacitor banks (TSC/TSF) apply delta wiring. To optimize effect of reactive power compensating and harmonic filtering, TSC capacity and branch configuration must be designed according to reactive power variation and harmonic components from nonlinear load. Technical features: SN Parameters Value 1 Rated voltage AC220V~1140V 2 Operation voltage 0.8~1.1Un 3 Rated frequency 50Hz/60Hz (Option) 4 Capacitor wiring mode Delta/Star (Option) 5 Switching mode Cycle/sequence/coded combination (Option) 6 Response time <20ms 7 Allowable maximum over current 1.3 times of rated current 8 Control steps 1~12/1~16 (Option) 9 Multiple units operation mode Parallel 10 Power loss <0.5% 11 Communication modes Modbus/RS485/232/CAN/GPRS etc (Option) 12 IP IP40 (customized) 13 Cooling mode Air cooling 14 Leading in mode Bottom/Top/Busbar (Option) 15 Altitude <1500 M 16 Ambient temperature -200C~+500C 17 Ambient humidity <95% 18 Operation environment No condensation, no corrupt gas, no conductive dust, no explosive and inflammable materials 19 Installation requirement No vibration, inclination≤50 20 Switching characteristic Current zero-crossing switching 21 Harmonic display Measure and display 2nd ~25th 22 Phase sequence protection Fault phase, phase loss 23 Thyristor protection Over-temperature protection and self-recovery 24 LCD display Real time current and voltage 25 Emergency protection Emergency stop switch 26 Compensation mode Three-phase compensation, phase splitting compensation 27 Protection modes Over current, over voltage, short-circuit, quick break

What is Power Factor? Power that is used by electrical equipment is known as real power. A site may also draw power that is not directly used, this is known as reactive power. The combination of the two is known as apparent power. Power Factor is the relationship between real and apparent power. If a site has poor Power Factor, it could be paying for energy that cannot be used. What is Powre Factor correction? Power Factor Correction (PFC) equipment is a technology which when installed allows the consumer to reduce their electricity bill by maintaining the level of reactive power consumption. If a sites Power Factor falls below a predetermined figure then the electricity company adds reactive power charges to your bill. In general, the strain on electrical infrastructure is reduced if Power Factor is good. Power factor correction PFC systems introduce a reactive load which supplies reactive power of an opposite sign to that exported by a site, thereby having a cancelling effect. The ideal Power Factor ratio is 1:0. Poor Power Factor has a negative impact on a site including drawing more power from the network causing losses at transformers, reducing effective capacity and incurring ‘poor Power Factor’ or ‘reactive power’ charges from the supplier. Advantages of improved power factor include reducing power demand from the network (which will result in lower electricity bills), prolonging lifespan of equipment, reducing losses in supply transformers and increasing the effective capacity of your electrical network. What we offer? 0.4kV Automatic power factor correction 3.3kV Automatic power factor correction:contactors 10kV Automatic power factor correction:contactors

POWER FACTOR CORRECTION The power factor of a load is defined as the ratio of active power to apparent power, i.e. kW : kVA and is referred to as cos
. The closer cos
is to unity, the less reactive power is drawn from the supply. For system with a low power factor the transmission of electric power in accordance with existing standards results in higher expenses both for the supply distribution companies and the consumer. In general terms, as the power factor of a three phase system decreases, the current rises. The heat dissipation in the system rises proportionately by a factor equivalent to the spare of the current. Types of Power Factor Correction : - Single or Fixed PFC, compensating for the reactive power of individual inductive loads at the point of connection so reducing the load in the connecting cables (typical for single, permanently operated loads with a constant power) - Group PFC, connecting on fixed capacitor to a group simultaneously operated inductive loads (e.g. group of motors, discharge lamp) - Bulk PFC, typical for large electrical systems with fluctuating load where it is common to connect a number of capacitors to 3 main power distribution station or substation. The capacitors are controlled by a microprocessor based relay which continuously monitors the reactive power demand on the supply. The relay connects or disconnects the capacitors to compensate for the actual reactive power of the total load and to reduce the overall demand of the supply.

Hybrid power factor correction Hybrid Power Factor Correction provide an instantaneous and effective response to power quality problems in low or high voltage electric power systems with lower cost. They enable longer equipment lifetime, higher process reliability, improved power system capacity and stability, and reduced energy losses, complying with most demanding power quality standards and grid codes. SVG TSC hybrid power factor correction SVG TSC mixed reactive power compensation Active power factor correction systems utilise power electronics and digital control to achieve active reactive current compensation for specific and high performance solutions. The  active power factor correction unit utilises closed loop control to correct power factor with a ¼ cycle (5mS) response.  This is suitable for unsteady fast changing loads such as cranes, welders, saws and debarking machines. However, sites containing loads such as these generally have a steadier base load. Considering active power factor correction produces a significant amount of heat, the question is whether the whole site needs active power factor correction when only part of the site needs it.A hybrid power factor correction system is comprised from both capacitor based and active power factor correction. Active power factor correction is used to cope with the unsteady fast changing portion of total load while capacitor banks support correction by correcting the steadier base load. This system offers the high level performance of an active system combined with the cost effectiveness offered by capacitor bank correction. Typical Design ◆SVG+SVC(Thyristor) ◆Hybrid Active Power Factor Correction with filters Features Hybrid power factor correction is completely step-less, instantaneous, and precise. Moreover, it can help clients realize significant fuel savings on DG operation. Furthermore, ZDDQ's unique priority setting feature allows you to get the maximum out of the installed filter capacity by using any spare capacity for harmonic compensation, load balancing, and neutral compensation Synchronous Rotating Frame Principal for best performance Ultra fast compensation Proven performance on welding Selective Harmonic compensation Step-less Reactive Power Compensation Negative Sequence Compensation (load balancing) Zero Sequence Compensation (neutral compensation) Benefits Performance of Active with cost effectiveness of passive Compliance with prescribed harmonic limits - No penalty Unity Power Factor - higher savings Reduced energy (kVAh) charges - higher savings Reduced peak demand charges - higher savings Reduced fuel consumption in generators - higher savings Ultra fast compensation - effective with fast fluctuating load Proven performance on welding Optimum capacity utilization of electrical infrastructure Optimum capacity utilization of backup generators Improved voltage profile Reduced risk of transformer failure - higher uptime Reduced risk of equipment failure - high...

Devices consuming electrical energy present two types of loads: resistive and reactive. Those purely resistive are characterized because the current absorbed is placed in phase with the applied voltage. This is the case of incandescent lamps, electrical heaters, and so on.

MEC/Multifunction Electricity Controller & Optimizer Multifunction Electricity Controller system has a stronger ability in restraining the voltage fluctuation and flickering, effectively compensates the voltage drops with the drop depth and width respectively below 50% and within 100ms, and effectively restrains the three-phase imbalance, rendering superior reliability and stability, With the response time smaller than 3ms it can solve the defects of traditional shunt capacitors and well satisfy the requirements on the quality improvement of electric energy and energy-saving application of power distribution network. Our Solutions Advanced Static var generator APF+SVG ZDDQ MEC Products Adanced static var generator Low voltage static var generator and active power filter system Advanced Static Var Generator static var generator and active harmonic filter system Advanced SVG The Advanced Static Var Generator provides the same dynamic performance as the SVG with the added benefit of combining harmonic mitigation. Available in 50/100/150,kVar wall mount and 100/150kVar cabinet mount modules, 400/480/690VAC three phase Extend your Power Factor Correction Performance The requirement for power factor correction is the number one power quality issue faced by the vast majority of industrial and commercial installations. The second biggest power quality issue is harmonic mitigation. Commercial installations will often have elevated 3rd harmonics owing to single phase non-linear loads such as computer switch mode power supplies, LED lighting, electronics lighting ballasts, inverter heat pumps. Add a computer data centre backed up by UPS containing a six pulse rectifier and 5th, 7th, 11th harmonics can be added into the mix. Variable Speed Drives controlling air handler units within building HVAC systems can further elevate the 5th, 7th, 11th harmonics Industrial installations will often have high levels of variable speed drive loading as automation systems improve efficiencies and productivity. It is no uncommon to see very high levels of current harmonics and voltage harmonic distortion resulting from six pulse VSDs drawing predominantly 5th, 7th 11th harmonics. Wouldn’t it be great if you could address both power factor correction and harmonic mitigation in one cost effective unit. The Advanced Static Var Generator (ASVG) does just that. Power Factor Correction And Harmonics Filtering in One Unit Reactive power compensation: Cos ϕ = 1.00 Capacitive and Inductive compensation: -1 to +1 All the features and benefits of the SVG Mitigation of 3rd, 5th, 7th, 11th harmonic orders Unit capacity can be shared 50/50 between power factor correction and harmonics correction Current imbalance correction can correct for load imbalance across all three phases The 3rd, 5th, 7th, 11th harmonic orders are the most prevalent in the majority of installations. A correctly sized ASVG can not only correct your displacement power factor to unity but also reduce your harmoni...

Low voltage intelligent power capacitor This is a new generation of energy-saving reactive power compensation device which can effectively reduce capacitor loss/wastage of coil, improve power factor and electrical quality in 0.4KV low voltage network. This product onsists of intelligent measurement and control unit, passing zero switch, rpotection unit and 2 triangle type /1 Y type LV power capacitor. Heavy structure and bulky size no longer exist, the product is smaller, easy to do maintenance,lower loss and longer lifetime with better price. Meet high requirement of modern intelligent power network to power compensation. Main functions Filtration function Function of Switching without surge Respective compensation function Measurement Protection function Signaling function Communication function Connection function Intelligent network control Self-diagnosed function What we offer ◆Integrated Capaicotrs with Thyristor ◆Intergrated Capacitors with Combination switch ◆Intergrated Capacitors with Contactors Remark:Reactors optional

Power Quality Power quality refers to the ability of electrical equipment to consume the energy being supplied to it in an efficient and effective manner. A number of power quality issues including electrical harmonics, poor power factor, voltage instability and imbalance impact on the efficiency of electrical equipment. This has a number of consequences including: Higher energy usage and costs. Higher maintenance and repair costs. Equipment instability and failure resulting in process or business disruption. How is your Power Quality? Power Quality – the efficiency and effectiveness of power supply. Good power quality is critical in efficient and uninterrupted industrial processes. Poor power quality can result in unstable equipment operation or failure, inefficiencies and reduced equipment lifespan, interruption of supply and plant down-time. ZDDQ specialise in evaluating, auditing and addressing a wide range of power quality issues to increase plant, motor and equipment efficiencies and the bottom line. What solution is right for us? Power consumption can be influenced by an intricate and complex set of variables. Our deep knowledge of power supply and electrical systems allow us to pinpoint your requirements as a power user and design or assign a solution that addresses your needs. This is generally done in 2 ways: By understanding your power usage and any problems that may be occurring, our experienced people will recommend the right solution. ZDDQ can perform a full power audit including data logging over a set period of time. This can allow an intimate knowledge of your power profile allowing us to develop a cost benefit analysis against a range of technologies of combination of technologies. Our Technologies and Solutions are Varied Power Quality products can be sorted in five general categories 1. Active Power Filters Active power filters (APF) are devices connected in parallel with the load to be compensated. They can be understood as controlled current sources that provide any kind of current waveform (in terms of phase, amplitude and frequency) in real time . APF are flexible, high performance and cost-effective solutions used to mitigate all the power quality problems generated by the equipment installed in electric power systems, enhancing equipment operating life time, and improving power system capacity.Active Power Filter products include: Active Harmonic Filters (AHF) Static VAR Generators (SVG) Active Load Balancers (ALB) Hybrid VAR Compensators (HVC) 2. Power Factor Correction Power Factor Correction (PFC) aims to improve power factor and hence power quality, switching in capacitors to offset usually inductive loads, for example electric motors. PFC systems increase the efficiency of power supply, delivering immediate cost savings on electricity.Technologies in this group include: Power Factor Correction (PFC) Smart Power Factor Correction Static VAR Generators (SVG) Hybrid VAR Compensators (HVC) 3. Static Compensators(SVG and...

Energy Saving Everyone wants to save money on their energy bill. Many facilities have mandates to save energy. Improving energy efficiency offers huge advantages to businesses—reducing the costs of energy and operations— and increasing sustainability. Reduced power costs can be achieved by reducing the voltage received and increasing the quality of the power. ZDDQ develop technologies to achieve efficiencies for industrial and commercial high energy users through standardised and customised solutions. Reduce power consumption and reduce your costs and environmental footprint. Technologies for reducing Electricity Bill, ◆Power factor correction(PFC) – by reducing reactive power consumption ◆Active Hamonic Filter– by eliminating unwanted harmonics ◆Static VAR Generators(SVG) – through creating efficiencies by adapting to fast changing loads   Save money by saving energy One of the best ways to save money on an electric bill is to reduce the amount of energy used in a facility, either through the use of energy-efficient devices, or through intelligent building control systems. Energy-efficient devices can range from variable frequency drives (VFDs) for motor control, to utilizing LED lighting, or high-efficiency motors and transformers. Intelligent building controls can leverage new or existing technology to reduce energy consumption through load management, lighting control and advanced thermostats. This section will explore, in detail, the methods available to save money through directly reducing energy consumption in facilities. Three main load types dominate electricity use in commercial facilities. HVAC, lighting and plug loads (office device and computers) combine to represent almost 85% of all electric energy consumed by commercial customers.